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, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Depreciation and amortization (foreign currency purchase contracts)	$ (4,206)	$ (4,279)	$ (13,133)	$ (13,515)
Costs of products sold (excluding depreciation and amortization)(futures contracts ? copper and aluminum)	(84,378)	(67,990)	(250,685)	(213,011)
Income (loss) before income taxes	2,121	(1,175)	4,697	2,116
Other income – net	3,174	2,006	7,019	4,694
Income tax provision	(987)	(291)	(1,432)	(2,044)
Net income (loss) attributable to Ampco-Pittsburgh	846	(1,589)	2,894	(359)
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	277	472	833	1,418
Income tax provision	4	(15)	0	(47)
Net income (loss) attributable to Ampco-Pittsburgh	281	457	833	1,371
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)	(7)	(6)	(20)	(20)
Costs of products sold (excluding depreciation and amortization)(futures contracts ? copper and aluminum)	386	(298)	132	(1,004)
Income (loss) before income taxes	379	(304)	112	(1,024)
Income tax provision	(12)	0	(4)	0
Net income (loss) attributable to Ampco-Pittsburgh	$ 367	$ (304)	$ 108	$ (1,024)