CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Unaudited) - 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, 2021			290,466
Balance at beginning 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 beginning of period, treasury stock (in shares) at Jun. 30, 2022							(46,155)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	296,697	295,441			295,441			1,256
Other comprehensive income (loss)	(25,725)	(25,725)				(25,725)
Treasury stock acquired through surrender of shares for tax withholding (in shares)							(4)
Treasury stock acquired through surrender of shares for tax withholding	(82)	(82)					$ (82)
Issuance of stock through share-based compensation plans (in shares)			322
Issuance of stock through share-based compensation plans	1,740	1,740	$ 1	1,739
Share-based compensation	7,119	7,119		7,119
Cash dividends declared	(24,474)	(24,474)			(24,474)
Subsidiary dividends to non-controlling interests	(271)							(271)
Balance at end of period, common stock (in shares) at Jun. 30, 2022			290,788
Balance at end of period at Jun. 30, 2022	3,227,550	3,196,295	$ 291	1,985,992	1,434,906	(5,747)	$ (219,147)	31,255
Balance at end of period, treasury stock (in shares) at Dec. 31, 2021							(46,151)
Balance at beginning of period, common stock (in shares) at Mar. 31, 2022			290,687
Balance at beginning of period at Mar. 31, 2022	3,126,822	3,096,123	$ 291	1,982,113	1,322,370	10,496	$ (219,147)	30,699
Balance at beginning of period, treasury stock (in shares) at Jun. 30, 2022							(46,155)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	125,469	124,778			124,778			691
Other comprehensive income (loss)	(16,243)	(16,243)				(16,243)
Issuance of stock through share-based compensation plans (in shares)			101
Issuance of stock through share-based compensation plans	258	258		258
Share-based compensation	3,621	3,621		3,621
Cash dividends declared	(12,242)	(12,242)			(12,242)
Subsidiary dividends to non-controlling interests	(135)							(135)
Balance at end of period, common stock (in shares) at Jun. 30, 2022			290,788
Balance at end of period at Jun. 30, 2022	$ 3,227,550	3,196,295	$ 291	1,985,992	1,434,906	(5,747)	$ (219,147)	31,255
Balance at end of period, treasury stock (in shares) at Mar. 31, 2022							(46,155)
Balance at beginning of period, common stock (in shares) at Dec. 31, 2022	245,091		291,249
Balance at beginning 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 beginning of period, treasury stock (in shares) at Jun. 30, 2023	(46,269)						(46,269)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 109,668	109,637			109,637			31
Other comprehensive income (loss)	(15,267)	(15,267)				(15,267)
Treasury stock acquired through surrender of shares for tax withholding (in shares)							(111)
Treasury stock acquired through surrender of shares for tax withholding	(2,823)	(2,823)					$ (2,823)
Issuance of stock through share-based compensation plans (in shares)			709
Issuance of stock through share-based compensation plans	1,925	1,925	$ 1	1,924
Share-based compensation	6,787	6,787		6,787
Cash dividends declared	(36,861)	(36,861)			(36,861)
Subsidiary dividends to non-controlling interests	$ (271)							(271)
Balance at end of period, common stock (in shares) at Jun. 30, 2023	245,689		291,958
Balance at end of period at Jun. 30, 2023	$ 3,762,859	3,732,150	$ 292	2,005,055	1,947,420	1,432	$ (222,049)	30,709
Balance at end of period, treasury stock (in shares) at Dec. 31, 2022	(46,158)						(46,158)
Balance at beginning of period, common stock (in shares) at Mar. 31, 2023			291,814
Balance at beginning of period at Mar. 31, 2023	$ 3,727,163	3,696,477	$ 292	2,001,575	1,901,569	15,090	$ (222,049)	30,686
Balance at beginning of period, treasury stock (in shares) at Jun. 30, 2023	(46,269)						(46,269)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 64,444	64,286			64,286			158
Other comprehensive income (loss)	(13,658)	(13,658)				(13,658)
Issuance of stock through share-based compensation plans (in shares)			144
Issuance of stock through share-based compensation plans	401	401		401
Share-based compensation	3,079	3,079		3,079
Cash dividends declared	(18,435)	(18,435)			(18,435)
Subsidiary dividends to non-controlling interests	$ (135)							(135)
Balance at end of period, common stock (in shares) at Jun. 30, 2023	245,689		291,958
Balance at end of period at Jun. 30, 2023	$ 3,762,859	$ 3,732,150	$ 292	$ 2,005,055	$ 1,947,420	$ 1,432	$ (222,049)	$ 30,709
Balance at end of period, treasury stock (in shares) at Mar. 31, 2023							(46,269)