Interim Financial Statements - Schedule of Investment Tax Credits and Grants Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Investment Tax Credits
Government Assistance [Line Items]
Government assistance, asset, current	$ 33,604	$ 33,604
Government assistance, asset, noncurrent	81,080	0
Grant Receivable
Government Assistance [Line Items]
Government assistance, asset, current	429	0
Government assistance, asset, noncurrent	$ 46,884	$ 13,321

Amount of asset from government assistance, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

Name:	us-gaap_GovernmentAssistanceAmountCumulativeCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of asset from government assistance, classified as noncurrent.

+ References

+ Details

Name:	us-gaap_GovernmentAssistanceAmountCumulativeNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Name:	us-gaap_GovernmentAssistanceLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_GovernmentAssistanceTypeAxis=amkr_InvestmentTaxCreditsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GovernmentAssistanceTypeAxis=amkr_GrantReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: