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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Depreciation and amortization (foreign currency purchase contracts)	$ (4,382)	$ (4,206)	$ (13,110)	$ (13,133)
Costs of products sold (excluding depreciation and amortization) (futures contracts - copper and aluminum)	(84,490)	(84,101)	(256,333)	(249,700)
Income (loss) before income taxes	1,311	2,398	3,757	5,682
Other (loss) income - net	1,959	3,174	3,424	7,019
Income tax (provision) benefit	(76)	(987)	(541)	(1,432)
Net income (loss) attributable to Ampco-Pittsburgh	809	1,123	1,908	3,879
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 (loss) income - net	(223)	277	(670)	833
Income tax (provision) benefit	(12)	4	(58)	0
Net income (loss) attributable to Ampco-Pittsburgh	(235)	281	(728)	833
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)	(6)	(7)	(20)	(20)
Costs of products sold (excluding depreciation and amortization) (futures contracts - copper and aluminum)	146	386	(33)	132
Income (loss) before income taxes	140	379	(53)	112
Income tax (provision) benefit	(5)	(12)	1	(4)
Net income (loss) attributable to Ampco-Pittsburgh	$ 135	$ 367	$ (52)	$ 108