Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 81,185	$ 75,674	$ 260,413	$ 241,515
Operating costs and expenses:
Costs of products sold (excluding depreciation and amortization)	67,990	59,461	213,011	189,604
Selling and administrative	10,910	11,445	34,538	33,474
Depreciation and amortization	4,279	4,511	13,515	13,863
Loss on disposal of assets	367	79	334	131
Total operating costs and expenses	83,546	75,496	261,398	237,072
(Loss) income from operations	(2,361)	178	(985)	4,443
Other income:
Investment-related income	14	1,215	1,079	1,327
Interest expense	(834)	(1,018)	(2,672)	(3,228)
Other income – net	2,006	1,493	4,694	2,510
Total other income	1,186	1,690	3,101	609
(Loss) income before income taxes	(1,175)	1,868	2,116	5,052
Income tax (provision) benefit	(291)	(630)	(2,044)	1,649
Net (loss) income	(1,466)	1,238	72	6,701
Less: Net income attributable to noncontrolling interest	123	270	431	923
Net (loss) income attributable to Ampco-Pittsburgh	$ (1,589)	$ 968	$ (359)	$ 5,778
Net (loss) income per share attributable to Ampco-Pittsburgh common shareholders:
Basic	$ (0.08)	$ 0.07	$ (0.02)	$ 0.45
Diluted	$ (0.08)	$ 0.07	$ (0.02)	$ 0.43
Weighted average number of common shares outstanding:
Basic	19,093	13,343	18,905	12,915
Diluted	19,093	14,454	18,905	13,585