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[Text Block] Fair Value By Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Treasury stock, at cost, 46,151 and 46,094 shares in 2021 and 2020, respectively Treasury Stock, Value Facility Costs Facility Closing [Member] Earnings Per Share Earnings Per Share [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Factoring of Accounts Receivable [Line Items] Factoring of Accounts Receivable [Line Items] [Line Items] for Factoring of Accounts Receivable [Table] Current liabilities: Liabilities, Current [Abstract] Entity Shell Company Entity Shell Company Treasury stock acquired through surrender of shares for tax withholding, shares Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Factoring of Accounts Receivable Factoring of Accounts Receivable [Text Block] Factoring of Accounts Receivable Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Term loan, applicable bank rate plus 1.98%, due December 2028 Term Loan Due December 2028 [Member] Term Loan Due December 2028 [Member] Short-term investments (amortized cost of $160,972 and $133,744 in 2021 and 2020, respectively) Short-term Investments