Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Shares used in computing per common share amounts: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Debt Conversion Terms One, Before July 15, 2030 Debt Conversion Terms One, Before July 15, 2030 [Member] Debt Conversion Terms One, Before July 15, 2030 Short-Term Debt, Type [Axis] Short-Term Debt, Type [Axis] Title of 12(b) Security Title of 12(b) Security Carrying Value Reported Value Measurement [Member] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Net income attributable to Amkor common stockholders, diluted Net Income (Loss) Available to Common Stockholders, Diluted Document Fiscal Year Focus Document Fiscal Year Focus Revenue expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Adjustment to Compensation, Amount Adjustment to Compensation Amount Pledged Status [Axis] Pledged Status [Axis] Financial Instrument [Axis] Financial Instrument [Axis] Kevin K. Engel [Member] Kevin K. Engel Segment Reporting [Abstract] Common stock, $0.001 par value, 500,000 shares authorized; 295,060 and 293,756 shares issued; and 247,804 and 247,303 shares outstanding in 2026 and 2025, respectively Common Stock, Value, Issued Payroll and benefits Employee-related Liabilities, Current Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Derivative Instrument [Axis] Derivative Instrument [Axis] 5.875% Senior notes, due October 2033 Senior Notes Due October 2033 [Member] Senior Notes Due October 2033 Debt instrument, convertible, conversion price (in dollars per share) Debt Instrument, Convertible, Conversion Price Amendment Flag Amendment Flag Current liabilities: Liabilities, Current [Abstract] Debt and Equity Securities, FV-NI [Line Items] Debt and Equity Securities, FV-NI [Line Items] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Payments of finance lease obligations Finance Lease, Principal Payments Net income attributable to Amkor per common share: Earnings Per Share Data [Abstract] Earnings Per Share Data Number of reportable segments not disclosed flag Number Of Reportable Segments Not Disclosed Flag Number Of Reportable Segments Not Disclosed Flag Short-term investments, Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Asset-backed securities Asset-backed securities Asset-Backed Securities [Member] Finance lease assets Finance Lease, Right-of-Use Asset, before Accumulated Amortization Schedule of Debt Securities Available-for-Sale Debt Securities, Available-for-Sale [Table Text Block] Other cost of sales Other Cost of Operating 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