Accumulated Other Comprehensive Loss - Line Items Affected on Consolidated Statements of Operations for Components Reclassified from Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Depreciation and amortization (foreign currency purchase contracts)	$ (18,611)	$ (17,674)
Costs of products sold (excluding depreciation and amortization) (futures contracts - copper and aluminum)	(336,809)	(347,781)
Income (loss) before income taxes	5,046	(39,277)
Other – net	4,376	4,516
Income tax provision	(2,695)	1,158
Net income (loss) attributable to Ampco-Pittsburgh	438	(39,928)
Amortization of Unrecognized Employee Benefit Costs [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other – net	(725)	(891)
Net income (loss) attributable to Ampco-Pittsburgh	(725)	(891)
Derivatives [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Depreciation and amortization (foreign currency purchase contracts)	(27)	(27)
Costs of products sold (excluding depreciation and amortization) (futures contracts - copper and aluminum)	(227)	59
Income (loss) before income taxes	(254)	32
Income tax provision	6	(2)
Net income (loss) attributable to Ampco-Pittsburgh	$ (248)	$ 30