Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 1,609	$ 314
Adjustments for changes in:
Foreign currency translation	(2,614)	(856)
Unrecognized employee benefit costs (including effects of foreign currency translation)	146	57
Fair value of cash flow hedges	443	310
Reclassification adjustments for items included in net income:
Amortization of unrecognized employee benefit costs	365	362
Settlements of cash flow hedges	(95)	(331)
Other comprehensive loss	(1,755)	(458)
Comprehensive loss	(146)	(144)
Less: Comprehensive (loss) income attributable to noncontrolling interest	(8)	181
Comprehensive loss attributable to Ampco-Pittsburgh	$ (138)	$ (325)