Organization, Consolidation and Presentation of Financial Statements [Abstract] Description of Business Nature of Operations [Text Block] Basis of Presentation Basis Of Presentation [Policy Text Block] Basis Of Presentation [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Consolidation of Variable Interest Entities Consolidation, Variable Interest Entity, Policy [Policy Text Block] Foreign Currency Translation Foreign Currency Transactions and Translations Policy [Policy Text Block] Risks and Concentrations Concentration Risk Disclosure [Text Block] Contingencies and Litigation Commitments and Contingencies, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Inventories Inventory, Policy [Policy Text Block] Other Current Assets Other Current Assets [Text Block] Property, Plant and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Goodwill Goodwill and Intangible Assets, Policy [Policy Text Block] Other Assets Schedule of Other Assets, Noncurrent [Table Text Block] Fair Value Measurements Fair Value of Financial Instruments, Policy [Policy Text Block] Revenue Recognition Revenue from Contract with Customer [Policy Text Block] Research and Development Costs Research and Development Expense, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Income Tax Disclosure [Abstract] Tax Credit Carryforward [Table] Tax Credit Carryforward [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] U.S. Federal Domestic Tax Authority [Member] Foreign Foreign Tax Authority [Member] Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] U.S. Foreign Tax Credits Foreign Tax Credit Carryforward [Member] Foreign Tax Credit Carryforward [Member] U.S. Other Tax Credits Other Tax Credit Carryforward [Member] Other Tax Credit Carryforward [Member] Tax Credit Carryforward [Line Items] Tax Credit Carryforward [Line Items] Tax Credits Tax Credit Carryforward, Amount Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Director Director [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Stock Options Employee Stock Option [Member] Restricted shares Restricted Stock [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2007 Plan Two Thousand Seven Equity Incentive Plan [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based compensation Share-based Compensation Deferred income tax benefits for stock options and restricted stock Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Number of shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Number of shares available for grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Expiration period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Unrecognized compensation expense from Restricted Stock Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Weighted-average period of recognition of unrecognized compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Restricted shares vesting (as a percent) Restricted Shares Vesting Percentage The annual rate at which restricted share awards vest to employees. Statement of Comprehensive Income [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Adjustments to unrealized components of defined benefit pension plans Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Foreign currency translation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Comprehensive income attributable to Amkor Comprehensive Income (Loss), Net of Tax, Attributable to Parent Factoring of Accounts Receivable [Abstract] Factoring of Accounts Receivable [Abstract] Factoring of Accounts Receivable [Table] Factoring of Accounts Receivable [Table] Factoring of Accounts Receivable [Table] Factoring of Accounts Receivable [Axis] Factoring of Accounts Receivable [Axis] Factoring of Accounts Receivable [Axis] Factoring of Accounts Receivable [Domain] Factoring of Accounts Receivable [Domain] [Domain] for Factoring of Accounts Receivable [Axis] Total Factored Total Factored [Member] Total Accounts Receivable Factored [Member] Factoring Fees Factoring Fees [Member] Factoring Fees [Member] Factoring of Accounts Receivable [Line Items] Factoring of Accounts Receivable [Line Items] [Line Items] for Factoring of Accounts Receivable [Table] Accounts Receivable Sold without Recourse Accounts Receivable Sold without Recourse Accounts Receivable Sold without Recourse Quarterly Financial Information Disclosure [Abstract] Net sales Revenues Gross Profit Gross Profit Operating income Operating Income (Loss) Income tax (benefit) expense Income Tax Expense (Benefit) Net income (loss) Net income (loss) attributable to Amkor Net Income (Loss) Attributable to Parent Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Condensed Income Statement [Table] Condensed Income Statement [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Korea KOREA, REPUBLIC OF Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Proceeds from sale of property, plant and equipment Proceeds from Sale of Property, Plant, and Equipment Gain on sale K1 factory Gain (Loss) on Disposition of Property Plant Equipment Net tax benefit from U.S. tax reform Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit) Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act of 2017, Incomplete 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State Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Current income tax expense (benefit) Current Income Tax Expense (Benefit) Deferred: Deferred Federal, State and Local, Tax Expense (Benefit) [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Deferred income tax expense (benefit) Deferred Income Tax Expense (Benefit) Income tax expense Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Defined Benefit Pension Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member] Foreign Currency Translation Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member] Total AOCI Including Portion Attributable to Noncontrolling Interest [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Balance at beginning of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive income (loss) Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Balance at end of period Payables and Accruals [Abstract] Accrued Expenses Accounts Payable and Accrued Liabilities Disclosure [Text Block] Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Description of Business and Summary of Significant Accounting Policies [Abstract] Description of Business and Summary of Significant Accounting Policies [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Variable Interest Entities by Classification of Entity [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Ownership Percentage Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Variable Interest Entity, Consolidated, Carrying Amount, Assets Variable Interest Entity, Consolidated, Carrying Amount, Assets Variable Interest Entity, Consolidated, Carrying Amount, Liabilities Variable Interest Entity, Consolidated, Carrying Amount, Liabilities Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Number of Shares Outstanding beginning balance Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Number of Shares Granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Number of Shares Exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Number of Shares Forfeited or expired Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Number of Shares Outstanding ending balance Number of Shares Fully vested and expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Number of Shares Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Weighted Average Exercise Price Per Share Outstanding beginning balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted Average Exercise Price Per Share Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Weighted Average Exercise Price Per Share Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Weighted Average Exercise Price Per Share Forfeited or expired (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Weighted Average Exercise Price Per Share Outstanding ending balance (in dollars per share) Weighted Average Exercise Price Per Share Fully vested and expected to vest (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Weighted Average Exercise Price Per Share Exercisable (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Weighted Average Remaining Contractual Term Outstanding (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Average Remaining Contractual Term Fully vested and expected to vest (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Average Remaining Contractual Term Exercisable (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Aggregate intrinsic value Outstanding ending balance (in dollars) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Aggregate intrinsic value Fully vested and expected to vest (in dollars) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value Aggregate intrinsic value Exercisable (in dollars) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair value assets measured on recurring basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] Cash equivalent money market funds (Level 1) Cash and Cash Equivalents, Fair Value Disclosure Restricted cash money market funds (Level 1) Restricted Cash Fair Value Disclosure Restricted Cash Fair Value Disclosure Defined Benefit Plan [Abstract] Expected contributions in next fiscal year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] Defined Benefit Plan, Expected Future Benefit Payment [Abstract] 2019 Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months 2020 Defined Benefit Plan, Expected Future Benefit Payment, Year Two 2021 Defined Benefit Plan, Expected Future Benefit Payment, Year Three 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year Four 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equipment Machinery and Equipment [Member] Capital lease machinery and equipment Assets Held under Capital Leases [Member] Software and computer equipment Software and Computer Equipment [Member] Software and Computer Equipment [Member] Furniture, fixtures and other equipment Furniture and Fixtures [Member] Construction in progress Construction in Progress [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Total property, plant and equipment Property, Plant and Equipment, Gross Less accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total property, plant and equipment, net Property, Plant and Equipment, Net Depreciation expense Depreciation Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving 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Reconciliation, Foreign Income Tax Rate Differential, Amount Foreign exchange (loss) gain Income Tax Reconciliation Foreign Exchange Gain Loss The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations that is attributable to gains or losses on foreign exchange. Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Adjustments related to prior years Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount U.S. tax reform (the Tax Act) Income tax credits generated Effective Income Tax Rate Reconciliation, Tax Credit, Amount Repatriation of foreign earnings and profits Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount Expiration of net operating losses and credits Effective Income Tax Rate Reconciliation, Expiration of Net Operating Losses Effective Income Tax Rate Reconciliation, Expiration of Net Operating Losses Other Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Valuation Allowance [Table] Valuation Allowance [Table] United States UNITED STATES Portugal PORTUGAL Other Other Foreign Countries [Member] Other Foreign Countries [Member] Valuation Allowance [Line Items] Valuation Allowance [Line Items] Total valuation allowance Deferred Tax Assets, Valuation Allowance Prepaid benefit cost (included in non-current assets) Assets for Plan Benefits, Defined Benefit Plan Accrued benefit liability (included in pension and severance obligations) Liability, Defined Benefit Plan Net amount recognized at year end Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position Summary of Property, plant and equipment Property, Plant and Equipment [Table Text Block] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Recognized actuarial (gain) loss Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit Net periodic pension cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Curtailment loss Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment Settlement (gain) loss Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Total pension expense Pension Cost (Reversal of Cost) Cost recognized Defined Contribution Plan, Cost Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Statement, Equity Components [Axis] Total Amkor Stockholders' Equity Parent [Member] Common Stock Common Stock [Member] Additional Paid- In Capital Additional Paid-in Capital [Member] Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Treasury Stock Treasury Stock [Member] Noncontrolling Interest in Subsidiaries Noncontrolling Interest [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance at beginning of period, shares Common Stock, Shares, Issued Balance at beginning of period, shares Treasury Stock, Shares Cumulative effect adjustment from standard adoption Cumulative Effect of New Accounting Principle in Period of Adoption Net income attributable to Amkor Net income attributable to noncontrolling interests Total other comprehensive income (loss) Treasury stock acquired through surrender of shares for tax withholding, shares Shares Paid for Tax Withholding for Share Based Compensation Treasury stock acquired through surrender of shares for tax withholding Adjustments Related to Tax Withholding for Share-based Compensation Issuance of stock through share-based compensation plans, shares Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Issuance of stock through share-based compensation plans Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Share-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Subsidiary dividends to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Balance at end of period, shares Balance at end of period, shares Commitments and Contingencies Disclosure [Abstract] Schedule of Future Minimum Rental Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Business Combinations [Abstract] Acquisitions Business Combination Disclosure [Text Block] Other Income and Expenses [Abstract] Interest income Interest Income, Deposits with Financial Institutions Foreign currency (gain) loss, net Foreign Currency Transaction Gain (Loss), before Tax Loss on debt retirement Gain (Loss) on Extinguishment of Debt Other (income) expense, net Other Nonoperating Income (Expense), Net The net of miscellaneous income and expense items that are combined together as a component of Other Nonoperating Income (Expense). Total other (income) expense, net Other Nonoperating Income (Expense) New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Schedule of New Accounting Pronouncements and Changes in Accounting Principles Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Schedule of Significant Accounting Policies [Table] Schedule of Significant Accounting Policies [Table] Schedule of Significant Accounting Policies [Table] Summary of Significant Accounting Policies [Line Items] Summary of Significant Accounting Policies [Line Items] Summary of Significant Accounting Policies [Line Items] Revenue recognition period Revenue From Contract With Customer, Period of Recognition Revenue From Contract With Customer, Period of Recognition Schedule of Income before Income Tax, Domestic and Foreign Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Summary of Valuation Allowance Summary of Valuation Allowance [Table Text Block] Summary of Operating Loss Carryforwards Summary of Operating Loss Carryforwards [Table Text Block] Summary of Tax Credit Carryforwards Summary of Tax Credit Carryforwards [Table Text Block] Schedule of Unrecognized Tax Benefits Rollforward Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Segment Reporting [Abstract] Revenue from External Customers by Products and Services Revenue from External Customers by Products and Services [Table Text Block] Net sales by country, and property, plant and equipment by physical location Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block] Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block] Document and Entity Information [Abstract] Document And Entity Information. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Pension and Severance Plans Pension and Severance Plans [Text Block] The entire disclosure for pension and severance defined benefit plans. Accounting Changes and Error Corrections [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] New Accounting Pronouncement Adjustment Scenario, Adjustment [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2017-07 Accounting Standards Update 2017-07 [Member] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] Restatement [Axis] Restatement [Axis] Restatement [Domain] Restatement [Domain] As Previously Reported Previously Reported [Member] Restatement Restatement Adjustment [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Income Statement: Income Statement [Abstract] Net sales Cost of sales Cost of Goods and Services Sold Income tax expense Balance Sheet: Statement of Financial Position [Abstract] Accounts receivable, net Accounts Receivable, Net, Current Inventories Inventory, Net Other Assets, Noncurrent Other Assets, Noncurrent Accrued expenses Accrued Liabilities, Current Other non-current liabilities Other Liabilities, Noncurrent Accumulated deficit Retained Earnings (Accumulated Deficit) SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] Schedule II - Valuation and Qualifying Accounts SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Debt Debt Disclosure [Text Block] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) London Interbank Offered Rate (LIBOR) [Member] Senior notes Senior Notes [Member] 6.625% Senior notes, due June 2021 Senior Notes Due June 2021 [Member] Senior notes due 2021. 6.375% Senior notes, due October 2022 Senior Notes Due October 2022 [Member] Senior Notes Due October 2022 [Member] Term loan, fixed rate at 3.70%, due May 2020 Fixed Rate Term Loan Due May 2020 [Member] Fixed Rate Term Loan Due May 2020 [Member] Term loans, fixed rate at 0.53%, due April 2018 Term Loans Due April 2018 [Member] Term Loans Due April 2018 [Member] Term loan, fixed rate at 0.86%, due June 2022 Term Loan Due June 2022 [Member] Term Loan Due June 2022 [Member] Term loan, fixed rate at 0.60%, due July 2022 Term Loan, Fixed Rate at 0.60% Due July 2022 [Member] Term Loan, Fixed Rate at 0.60% Due July 2022 [Member] Term loan, fixed rate at 1.30%, due July 2023 Term Loan, Fixed Rate at 1.30% Due July 2023 [Member] Term Loan, Fixed Rate at 1.30% Due July 2023 [Member] Repayments of debt Repayments of Long-term Debt Credit facility, borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Total debt Long-term Debt Including Related Party, Gross Amount of long-term debt, including related party debt, before deduction of unamortized discount or premium. Interest rate (as a percent) Debt Instrument, Interest Rate, Stated Percentage Interest rate spread (as a percent) Debt Instrument, Basis Spread on Variable Rate Amount of debt agreement Debt Instrument, Face Amount Remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Prior Service Cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Including Portion Attributable to Noncontrolling Interest [Member] Actuarial Net Gain (Loss) Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] Total Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] Amortization and settlement gain included in net periodic pension cost Net gain (loss) arising during period Estimated amortization of cost to be included in 2019 net periodic pension cost Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Quarterly Results (Unaudited) Quarterly Financial Information [Text Block] Property, Plant and Equipment [Table] Percentage of proceeds received Percentage of Proceeds Received The percentage of proceeds received from sale of property, plant, and equipment Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance, beginning of period Unrecognized Tax Benefits Additions based on tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Additions for tax positions of prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Reductions for tax positions of prior years Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Reductions from lapse of statutes of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Balance, end of period Income tax contingency [Abstract] Income tax contingency [Abstract] Unrecognized tax benefits, period increase (decrease) Unrecognized Tax Benefits, Period Increase (Decrease) Liability for uncertain tax positions Liability for Uncertainty in Income Taxes, Noncurrent Accrued and unpaid interest and penalties Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued New Accounting Standards New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] U.S. Federal Internal Revenue Service (IRS) [Member] U.S. State State and Local Jurisdiction [Member] Foreign Non-US [Member] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Loss Carryforwards and other details [Abstract] Income Taxes Textuals [Abstract] Income Taxes Textuals [Abstract] Operating loss carryforwards Operating Loss Carryforwards Tax credit carryforward Undistributed earnings of foreign subsidiaries Undistributed Earnings of Foreign Subsidiaries Repatriation of earnings estimated tax impact Repatriation Of Earnings Estimated Tax Impact The estimated tax impact (foreign withholding and federal income tax) that would be generated if undistributed earnings as of the balance sheet date were to be repatriated to the domestic country. Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Number of Shares Nonvested beginning balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Number of Shares Awards granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Number of Shares Awards vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Number of Shares Awards forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Number of Shares Nonvested ending balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Weighted Average Grant-Date Fair Value Nonvested beginning balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value Awards granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value Awards vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value Awards forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted Average Grant-Date Fair Value Nonvested ending balance (in dollars per share) Share-Based Compensation Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents, Current Accounts receivable, net of allowances of $677 and $803, respectively Other current assets Other Assets, Current Total current assets Assets, Current Property, plant and equipment, net Goodwill Goodwill Restricted cash Restricted Cash and Cash Equivalents, Noncurrent Other assets Total assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Short-term borrowings and current portion of long-term debt Debt, Current Trade accounts payable Accounts Payable, Current Capital expenditures payable Capital expenditures payable Amount owed for capital expenditures. Total current liabilities Liabilities, Current Long-term debt Long-term Debt, Excluding Current Maturities Pension and severance obligations Liability, Pension and Other Postretirement and Postemployment Benefits, Noncurrent Total liabilities Liabilities Commitments and contingencies (Note 15) Commitments and Contingencies Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, $0.001 par value, 10,000 shares authorized, designated Series A, none issued Preferred Stock, Value, Issued Common stock, $0.001 par value, 500,000 shares authorized, 285,352 and 285,129 shares issued, and 239,385 and 239,184 shares outstanding, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Retained earnings (accumulated deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Treasury stock, at cost, 45,967 and 45,945 shares, respectively Treasury Stock, Value Total Amkor stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interests in subsidiaries Stockholders' Equity Attributable to Noncontrolling Interest Total equity Total liabilities and equity Liabilities and Equity Land use rights Buildings and improvements Machinery and equipment Software and computer equipment Furniture, fixtures and other equipment Useful life Property, Plant and Equipment, Useful Life Unbilled receivables Unbilled Receivables, Current Other Income and Expense Other Income and Other Expense Disclosure [Text Block] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Fair Value Portion at Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Senior notes (Level 1) Revolving credit facilities and term loans (Level 2) Subsidiary Term Loans and Revolving Credit Facilities [Member] Subsidiary Term Loans and Revolving Credit Facilities [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Total financial instruments Debt Instrument, Fair Value Disclosure SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Valuation Allowance of Deferred Tax Assets SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] Balance at Beginning of Period SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Additions (Credited) Charged to Expense SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense Write-offs SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction Other SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Other Account Balance at End of Period Dilutive Securities Adjustments [Table] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Stock Options and Restricted Share Awards [Member] Stock Options Dilutive Effect [Member] Stock Options Dilutive Effect Dilutive Securities Adjustments [Line Items] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Net income available to Amkor common stockholders Net Income (Loss) Available to Common Stockholders, Diluted Weighted-average shares outstanding — basic Weighted Average Number of Shares Outstanding, Basic Effect of dilutive securities: Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract] Stock options and restricted share awards Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted-average shares outstanding — diluted Weighted Average Number of Shares Outstanding, Diluted Net income attributable to Amkor per common share: Earnings Per Share, Basic and Diluted [Abstract] Summarized Accrued expenses Schedule of Accrued Liabilities [Table Text Block] Expected life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Weighted-average grant date fair value per option granted Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Total debt Less: Unamortized premium and deferred debt costs, net Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Less: Short-term borrowings and current portion of long-term debt Long-term debt Non Current Long term Debt Including Related Party Non current long-term debt including related party. Gross profit Selling, general and administrative Selling, General and Administrative Expense Research and development Research and Development Expense Gain on sale of real estate Gain (Loss) on Disposition of Assets Total operating expenses Operating Expenses Operating income Interest expense Interest Expense Interest expense, related party Interest Expense, Related Party Other (income) expense, net Total other expense, net Nonoperating Income (Expense) Net income Net income attributable to noncontrolling interests Net income attributable to Amkor Net income attributable to Amkor per common share: Shares used in computing per common share amounts: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Diluted (in shares) Components of Deferred Tax Assets and Liabilities [Abstract] Net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards Income tax credits Deferred Tax Assets, Tax Credit Carryforwards Property, plant and equipment Deferred Tax Assets, Property, Plant and Equipment Deferred interest expense Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Interest Expense Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Interest Expense Accrued liabilities Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Receivable Deferred Tax Assets, Other Deferred Liabilities Deferred Tax Assets, Other Deferred Liabilities Unrealized foreign exchange loss Deferred Tax Assets, Unrealized Currency Losses Other Deferred Tax Assets, Other Total deferred tax assets Deferred Tax Assets, Gross Valuation allowance Total deferred tax assets net of valuation allowance Deferred Tax Assets, Net of Valuation Allowance Property, plant and equipment Deferred Tax Liabilities, Property, Plant and Equipment Deferred gain Deferred Tax Liabilities, Tax Deferred Income Unrealized foreign exchange gain Deferred Tax Liabilities, Unrealized Currency Transaction Gains Unbilled receivables Deferred Tax Liabilities, Unbilled Receivables Deferred Tax Liabilities, Unbilled Receivables Other Deferred Tax Liabilities, Other Total deferred tax liabilities Deferred Tax Liabilities, Gross Other assets Deferred Tax Assets, Net, Noncurrent Other non-current liabilities Deferred Tax Liabilities, Net, Noncurrent Net deferred tax assets Deferred Tax Assets, Net Quarterly Financial Information Quarterly Financial Information [Table Text Block] Tax benefit from income tax holiday Income Tax Holiday, Aggregate Dollar Amount Benefit from income tax holiday on diluted earnings per share (in dollars per share) Income Tax Holiday, Tax Benefit, Diluted Earnings Per Share Income Tax Holiday, Tax Benefit, Diluted Earnings Per Share Transition tax payable Effective Income Tax Reconciliation, Tax Cut and Jobs Act 2017, Transition Tax Payable Effective Income Tax Reconciliation, Tax Cut and Jobs Act 2017, Transition Tax Payable Income Tax Examination [Table] Income Tax Examination [Table] Income Tax Examination [Line Items] Income Tax Examination [Line Items] Reductions from lapse of statutes of limitations Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Amortization of deferred debt issuance costs and premiums Amortization of Debt Issuance Costs and Discounts Deferred income taxes Loss on debt retirement Loss (gain) on disposal of fixed assets, net Proceeds from insurance recovery for property, plant and equipment Gain on Business Interruption Insurance Recovery Other, net Other Noncash Income (Expense) Changes in assets and liabilities, net of acquisitions: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Inventories Increase (Decrease) in Inventories Other current assets Increase (Decrease) in Other Current Assets Other assets Increase (Decrease) in Other Noncurrent Assets Trade accounts payable Increase (Decrease) in Accounts Payable Accrued expenses Increase (Decrease) in Accrued Liabilities Pension and severance obligations Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Other non-current liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Payments for property, plant and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from insurance recovery for property, plant and equipment Proceeds from Insurance Settlement, Investing Activities Acquisition of business, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Other investing activities Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from revolving credit facilities Proceeds from Lines of Credit Payments of revolving credit facilities Repayments of Lines of Credit Proceeds from short-term debt Proceeds from Short-term Debt Payments of short-term debt Repayments of Short-term Debt Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt Payments of long-term debt Payments of long-term debt, related party Repayments of Related Party Debt Payments of capital lease obligations Repayments of Long-term Capital Lease Obligations Payment of deferred consideration for purchase of facility Final Installment Payment for Previous Acquisition The cash outflow attributable to a prior period acquisition whereby a portion of the fixed consideration was deferred to the current period. Proceeds from issuance of stock through share-based compensation plans Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Including Stock Options Other financing activities Proceeds from (Payments for) Other Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate fluctuations on cash, cash equivalents and restricted cash Effect of Exchange Rate on Cash and Cash Equivalents Net increase in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash, cash equivalents and restricted cash, beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents and restricted cash, end of period Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Cash paid during the period for: Cash Paid During Period For Abstract Cash Paid During Period For Interest Interest Paid, Excluding Capitalized Interest, Operating Activities Income taxes Income Taxes Paid Non-cash investing and financing activities: Noncash Investing and Financing Items [Abstract] Property, plant and equipment included in capital expenditures payable Capital Expenditures Incurred but Not yet Paid Equipment acquired through capital lease Capital Lease Obligations Incurred Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Advanced Products Advanced Products [Member] Advanced Products [Member] Mainstream Products Mainstream Products [Member] Mainstream Products [Member] Communications (smartphones, tablets, handheld devices) Sales Channel, Communications [Member] Sales Channel, Communications [Member] Automotive, industrial and other (driver assist, infotainment, safety, performance) Sales Channel, Automotive, Industrial And Other [Member] Sales Channel, Automotive, Industrial And Other [Member] Computing (datacenter, infrastructure, PC/laptop, storage) Sales Channel, Computing [Member] Sales Channel, Computing [Member] Consumer (set-top boxes, televisions, connected home, personal electronics, visual imaging) Sales Channel, Consumer [Member] Sales Channel, Consumer [Member] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Customer One Customer One [Member] Customer One [Member] Customer Two Customer Two [Member] Customer Two [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Sales Sales [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Product Concentration Risk [Member] Product Concentration Risk [Member] Customer Concentration Risk Customer Concentration Risk [Member] Europe, Middle East and Africa EMEA [Member] Asia Pacific Asia [Member] Total foreign countries Total Foreign Countries [Member] Total Foreign Countries [Member] Malaysia MALAYSIA Other foreign countries Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of operating segments Number of Operating Segments Concentration risk (as a percent) Concentration Risk, Percentage Income Taxes Income Tax Disclosure [Text Block] Payroll and benefits Employee-related Liabilities, Current Income taxes payable Accrued Income Taxes, Current Deferred revenue and customer advances Deferred Revenue and Credits, Current Accrued severance plan obligations (Note 12) Supplemental Unemployment Benefits, Severance Benefits Accrued interest Interest Payable, Current Accrued settlement costs Accrued settlement costs, current Accrued settlement costs, current Other accrued expenses Other Accrued Liabilities, Current Total accrued expenses Operating Leases Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total future minimum lease payments Operating Leases, Future Minimum Payments Due Capital Leases Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Capital Leases, Future Minimum Payments Due, Next Twelve Months 2020 Capital Leases, Future Minimum Payments Due in Two Years 2021 Capital Leases, Future Minimum Payments Due in Three Years 2022 Capital Leases, Future Minimum Payments Due in Four Years 2023 Capital Leases, Future Minimum Payments Due in Five Years Thereafter Capital Leases, Future Minimum Payments Due Thereafter Total future minimum lease payments Capital Leases, Future Minimum Payments Due Change in projected benefit obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Projected benefit obligation at January 1 Defined Benefit Plan, Benefit Obligation Service cost Interest cost Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Actuarial (gain) loss Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Effects of curtailment Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment Settlement Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement Foreign exchange (gain) loss Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss) Projected benefit obligation at December 31 Change in plan assets: Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Fair value of plan assets at January 1 Actual gain (loss) on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Employer contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Settlement Defined Benefit Plan, Plan Assets, Payment for Settlement Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Foreign exchange gain (loss) Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss) Fair value of plan assets at December 31 Funded status of the Plans at December 31 Defined Benefit Plan, Funded (Unfunded) Status of Plan Defined Benefit Plan, Liability Liability, Defined Benefit Plan [Abstract] Accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract] Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract] Aggregate projected benefit obligation Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation Aggregate fair value of plan assets Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract] Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract] Aggregate accumulated benefit obligation Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation Aggregate fair value of plan assets Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Discount rate for determining net periodic pension cost (as a percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Discount rate for determining benefit obligations at December 31 (as a percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Rate of compensation increase for determining net periodic pension cost (as a percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Rate of compensation increase for determining benefit obligations at December 31 (as a percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Expected rate of return on plan assets for determining net periodic pension cost (as a percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Property Plant and Equipment Policy Property Plant and Equipment Policy [Table Text Block] Property Plant and Equipment [Table Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Stock Options And Restricted Shares [Member] Stock Options And Restricted Shares [Member] Stock options and restricted shares. Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Stock options and restricted share awards Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Loss Contingencies [Table] Loss Contingencies [Table] Litigation Case [Axis] Litigation Case [Axis] Litigation Case Type [Domain] Litigation Case [Domain] Patent License Litigation Tessera Inc Legal Proceedings [Member] Tessera Inc Legal Proceedings [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Amount awarded to other party Litigation Settlement, Amount Awarded to Other Party Number of quarterly settlement payments Number of Quarterly Settlement Payments Number of Quarterly Settlement Payments Rent expense Operating Leases, Rent Expense, Net Non-lease long-term supply contract, remaining amount Purchase Obligation Non-lease Long-term Supply Contract, Remaining Amount Remaining amount to be expensed for long term purchase obligation supply contract. Factoring of Accounts Receivable Factoring of Accounts Receivable [Text Block] Factoring of Accounts Receivable 2019 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2020 Long-term Debt, Maturities, Repayments of Principal in Year Two 2021 Long-term Debt, Maturities, Repayments of Principal in Year Three 2022 Long-term Debt, Maturities, Repayments of Principal in Year Four 2023 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Valuation of money market funds and restricted cash using quoted market prices in active markets for identical assets Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Financial instruments that are not recorded at fair value Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Allowance Allowance for Doubtful Accounts Receivable, Current Preferred stock designated Series A, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock designated Series A, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock designated Series A, shares issued (in shares) Preferred Stock, Shares Issued Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Treasury stock, shares Schedule Of Accrued Severance Obligation Schedule Of Accrued Severance Obligation [Table Text Block] Schedule Of Accrued Severance Obligation [Table Text Block] Schedule of Changes in Projected Benefit Obligations and Fair Value of Plan Assets Schedule of Changes in Projected Benefit Obligations and Fair Value of Plan Assets [Table Text Block] Schedule of Changes in Projected Benefit Obligations and Fair Value of Plan Assets [Table Text Block] Schedule of Amounts Recognized in Balance Sheet Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Schedule of Amounts Recognized in Other Comprehensive Income (Loss) Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block] Components of net periodic pension cost Schedule of Net Benefit Costs [Table Text Block] Schedule of Assumptions Used Schedule of Assumptions Used [Table Text Block] Schedule of Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Schedule of Expected Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Summary of Short term Borrowings And Long term Debt Schedule of Debt [Table Text Block] Schedule of Interest Rates Schedule of Long-Term Interest Rates [Table Text Block] Schedule of Long-Term Interest Rates [Table Text Block] Schedule of Maturities of Long-term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] $75 million revolving credit facility, foreign currency funding-linked base rate plus 1.60%, due June 2018 Revolving Credit Facility Due June 2018 [Member] Revolving Credit Facility Due June 2018 [Member] Debt Instruments [Abstract] Debt Instruments [Abstract] Redemption price (as a percent) Debt Instrument, Redemption Price, Percentage Write off of deferred debt issuance cost Write off of Deferred Debt Issuance Cost Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Nanium [Member] Nanium [Member] Nanium [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Percentage of voting interests acquired Business Acquisition, Percentage of Voting Interests Acquired Schedule of Other Nonoperating Income (Expense) Schedule of Other Nonoperating Income (Expense) [Table Text Block] Other Postretirement Benefit Plans [Table] Schedule of Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits, by Title of Individual and by Type of Deferred Compensation [Table] Other Deferred Cash Compensation [Axis] Other Deferred Cash Compensation [Axis] Other Deferred Cash Compensation [Axis] Other Deferred Cash Compensation [Domain] Other Deferred Cash Compensation [Domain] Other Deferred Cash Compensation [Domain] Korean Severance Plan Korean Severance Plan [Member] Severance plan in the form of a lump-sum payment upon termination of employment (employees and directors), based on length of service, seniority and average monthly wages at the time of termination, which is not related to restructurings, pension plans or other post retirement benefit plans. Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Deferred Compensation Liability, Current and Noncurrent [Roll Forward] Deferred Compensation Liability, Current and Noncurrent [Roll Forward] Deferred Compensation Liability, Current and Noncurrent [Roll Forward] Balance at January 1 Deferred Compensation Cash-based Arrangements, Liability, Current and Noncurrent Provision of severance benefits Provision of Severance Benefits Provision related to lump-sum payment upon termination of employment (employees and directors), based on length of service, seniority and average monthly wages at the time of termination, which is not related to restructurings, pension plans or other post retirement benefit plans. Severance benefits are estimated assuming all eligible employees were to terminate their employment at the balance sheet date. Severance payments Payments for Employee Severance Lump-sum payments related to termination of employment (employees and directors), based on length of service, seniority and average monthly wages at the time of termination, which is not related to restructurings, pension plans or other post retirement benefit plans. Severance benefits are estimated assuming all eligible employees were to terminate their employment at the balance sheet date. Foreign currency (gain) loss Severance Benefits, Gain (Loss) Translation Adjustments Foreign currency translation adjustments related to the transactions for lump-sum payment upon termination of employment (employees and directors), based on length of service, seniority and average monthly wages at the time of termination, which is not related to restructurings, pension plans or other post retirement benefit plans. Severance benefits are estimated assuming all eligible employees were to terminate their employment at the balance sheet date. Balance at the end of year Payments remaining with the National Pension Fund Payments Remaining With Local Pension Fund Payments remaining with the Korean National Pension Fund. Total accrued severance plan obligations at December 31 Postemployment Benefits Liability Less current portion of accrued severance plan obligations (Note 10) Postemployment Benefits Liability, Current Non-current portion of accrued severance plan obligations Postemployment Benefits Liability, Noncurrent Summary of all common stock option activity Share-based Compensation, Stock Options, Activity [Table Text Block] Assumptions used in valuing the weighted average fair values of the options granted Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Restricted share activity Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block] Business Segments, Customer Concentrations and Geographic Information Segment Reporting Disclosure [Text Block]