Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (79,809)	$ 1,373	$ (1,187)
Adjustments for changes in:
Foreign exchange translation	(14,580)	(3,967)	(4,703)
Unrecognized employee benefit costs (including effects of foreign currency translation)	9,397	10,713	(21,392)
Unrealized holding gains (losses) on marketable securities	405	(239)	88
Fair value of cash flow hedges	398	(475)	(323)
Reclassification adjustments for items included in net (loss) income:
Amortization of unrecognized employee benefit costs	1,910	4,740	3,458
Realized gains from sale of marketable securities	(1,038)	(53)	(111)
Realized losses from settlement of cash flow hedges	108	435	95
Other comprehensive (loss) income	(3,400)	11,154	(22,888)
Comprehensive (loss) income	(83,209)	12,527	(24,075)
Less: Comprehensive loss attributable to noncontrolling interest	(103)	0	0
Comprehensive (loss) income attributable to Ampco-Pittsburgh	$ (83,106)	$ 12,527	$ (24,075)