Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net sales	$ 92,428	$ 74,778	$ 179,228	$ 165,841
Operating costs and expenses:
Costs of products sold (excluding depreciation and amortization)	75,433	59,983	145,021	130,143
Selling and administrative	12,070	10,199	23,628	22,029
Depreciation and amortization	4,493	4,653	9,236	9,352
(Gain) loss on disposal of assets	(37)	29	(33)	52
Total operating costs and expenses	91,959	74,864	177,852	161,576
Income (loss) from operations	469	(86)	1,376	4,265
Other income (expense):
Investment-related income	1,047	108	1,065	112
Interest expense	(943)	(994)	(1,838)	(2,210)
Other income – net	2,023	2,337	2,688	1,017
Total other income (expense)	2,127	1,451	1,915	(1,081)
Income before income taxes	2,596	1,365	3,291	3,184
Income tax (provision) benefit	(1,372)	(504)	(1,753)	2,279
Net income	1,224	861	1,538	5,463
Less: Net income attributable to noncontrolling interest	161	193	308	653
Net income attributable to Ampco-Pittsburgh	$ 1,063	$ 668	$ 1,230	$ 4,810
Net income per share attributable to Ampco-Pittsburgh common shareholders:
Basic	$ 0.06	$ 0.05	$ 0.07	$ 0.38
Diluted	$ 0.05	$ 0.05	$ 0.06	$ 0.37
Weighted average number of common shares outstanding:
Basic	18,981	12,740	18,810	12,698
Diluted	21,249	13,382	20,981	12,959