Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 102,519	$ 118,371	$ 210,013	$ 224,786
Operating costs and expenses:
Costs of products sold (excluding depreciation and amortization)	84,536	98,840	174,757	186,493
Selling and administrative	13,929	14,273	27,814	29,129
Depreciation and amortization	4,650	5,448	9,909	11,048
Impairment charge	0	0	10,082	0
Loss (gain) on disposal of assets	57	(1)	63	82
Total operating expenses	103,172	118,560	222,625	226,752
Loss from continuing operations	(653)	(189)	(12,612)	(1,966)
Other income (expense):
Investment-related income	1,360	43	1,400	67
Interest expense	(1,209)	(1,020)	(2,494)	(1,893)
Other – net	925	721	2,221	4,342
Total other income (expense)	1,076	(256)	1,127	2,516
Income (loss) from continuing operations before income taxes	423	(445)	(11,485)	550
Income tax provision	(644)	(546)	(1,287)	(83)
Net (loss) income from continuing operations	(221)	(991)	(12,772)	467
Loss from discontinued operations, net of tax	(3,391)	(1,709)	(5,633)	(1,778)
Net loss	(3,612)	(2,700)	(18,405)	(1,311)
Less: Net income attributable to noncontrolling interest	246	294	601	742
Net loss attributable to Ampco-Pittsburgh	$ (3,858)	$ (2,994)	$ (19,006)	$ (2,053)
Net (loss) income from continuing operations per common share:
Basic	$ (0.02)	$ (0.08)	$ (1.02)	$ 0.04
Diluted	(0.02)	(0.08)	(1.02)	0.04
Loss from discontinued operations, net of tax, per common share:
Basic	(0.27)	(0.14)	(0.45)	(0.14)
Diluted	(0.27)	(0.14)	(0.45)	(0.14)
Net loss per common share attributable to Ampco-Pittsburgh:
Basic	(0.31)	(0.24)	(1.52)	(0.17)
Diluted	$ (0.31)	$ (0.24)	$ (1.52)	$ (0.17)
Weighted average number of common shares outstanding:
Basic	12,576	12,439	12,537	12,401
Diluted	12,576	12,439	12,537	12,401