Accumulated Other Comprehensive Loss - Line Items Affected on Consolidated Statements of Operations for Components Reclassified from Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Depreciation and amortization (foreign currency purchase contracts)	$ (4,354)	$ (4,440)	$ (8,728)	$ (8,927)
Costs of products sold (excluding depreciation and amortization) (futures contracts - copper and aluminum)	(85,471)	(85,083)	(171,843)	(165,599)
Income (loss) before income taxes	1,148	3,315	2,446	3,284
Other income – net	98	2,433	1,465	3,845
Income tax provision	(152)	(389)	(465)	(445)
Net income (loss) attributable to Ampco-Pittsburgh	423	2,807	1,099	2,756
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 income – net	(265)	188	(447)	556
Income tax provision	(33)	(1)	(46)	(4)
Net income (loss) attributable to Ampco-Pittsburgh	(298)	187	(493)	552
Settlements of Cash Flow Hedges [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)	(8)	(6)	(14)	(13)
Costs of products sold (excluding depreciation and amortization) (futures contracts - copper and aluminum)	(68)	(163)	(179)	(254)
Income (loss) before income taxes	(76)	(169)	(193)	(267)
Income tax provision	3	5	6	8
Net income (loss) attributable to Ampco-Pittsburgh	$ (73)	$ (164)	$ (187)	$ (259)