CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Total Amkor Stockholders’ Equity	Common Stock	Additional Paid- In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Noncontrolling Interest in Subsidiaries
Balance at beginning of period, common stock (in shares) at Dec. 31, 2020			288,923
Balance at beginning of period at Dec. 31, 2020	$ 2,353,959	$ 2,325,699	$ 289	$ 1,953,378	$ 562,502	$ 27,270	$ (217,740)	$ 28,260
Balance at beginning of period, treasury stock (in shares) at Dec. 31, 2020							(46,094)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	645,607	642,995			642,995			2,612
Other comprehensive income (loss)	(7,292)	(7,292)				(7,292)
Treasury stock acquired through surrender of shares for tax withholding (in shares)							(57)
Treasury stock acquired through surrender of shares for tax withholding	(1,325)	(1,325)					$ (1,325)
Issuance of stock through share-based compensation plans (in shares)			1,543
Issuance of stock through share-based compensation plans	12,787	12,787	$ 1	12,786
Share-based compensation	10,970	10,970		10,970
Cash dividends declared	(41,558)	(41,558)			(41,558)
Subsidiary dividends to noncontrolling interests	(602)							(602)
Balance at end of period, common stock (in shares) at Dec. 31, 2021			290,466
Balance at end of period at Dec. 31, 2021	2,972,546	2,942,276	$ 290	1,977,134	1,163,939	19,978	$ (219,065)	30,270
Balance at end of period, treasury stock (in shares) at Dec. 31, 2021							(46,151)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	767,042	765,823			765,823			1,219
Other comprehensive income (loss)	(3,279)	(3,279)				(3,279)
Treasury stock acquired through surrender of shares for tax withholding (in shares)							(7)
Treasury stock acquired through surrender of shares for tax withholding	(161)	(161)					$ (161)
Issuance of stock through share-based compensation plans (in shares)			783
Issuance of stock through share-based compensation plans	5,649	5,649	$ 1	5,648
Share-based compensation	13,562	13,562		13,562
Cash dividends declared	(55,118)	(55,118)			(55,118)
Subsidiary dividends to noncontrolling interests	$ (540)							(540)
Balance at end of period, common stock (in shares) at Dec. 31, 2022	291,249		291,249
Balance at end of period at Dec. 31, 2022	$ 3,699,701	3,668,752	$ 291	1,996,344	1,874,644	16,699	$ (219,226)	30,949
Balance at end of period, treasury stock (in shares) at Dec. 31, 2022	(46,158)						(46,158)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 362,131	359,813			359,813			2,318
Other comprehensive income (loss)	(349)	(349)				(349)
Treasury stock acquired through surrender of shares for tax withholding (in shares)							(121)
Treasury stock acquired through surrender of shares for tax withholding	(3,109)	(3,109)					$ (3,109)
Issuance of stock through share-based compensation plans (in shares)			918
Issuance of stock through share-based compensation plans	3,550	3,550	$ 1	3,549
Share-based compensation	8,277	8,277		8,277
Cash dividends declared	(74,626)	(74,626)			(74,626)
Subsidiary dividends to noncontrolling interests	$ (540)							(540)
Balance at end of period, common stock (in shares) at Dec. 31, 2023	292,167		292,167
Balance at end of period at Dec. 31, 2023	$ 3,995,035	$ 3,962,308	$ 292	$ 2,008,170	$ 2,159,831	$ 16,350	$ (222,335)	$ 32,727
Balance at end of period, treasury stock (in shares) at Dec. 31, 2023	(46,279)						(46,279)