Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 397,904	$ 419,432
Operating costs and expenses:
Costs of products sold (excluding depreciation and amortization)	326,157	351,839
Selling and administrative	53,643	58,068
Depreciation and amortization	18,967	21,379
Impairment charge	10,082	0
Charge for asbestos litigation	0	32,910
(Gain) loss on disposal of assets	(37)	128
Total operating expenses	408,812	464,324
Loss from continuing operations	(10,908)	(44,892)
Other income (expense):
Investment-related income	1,417	533
Interest expense	(5,342)	(4,130)
Other – net	6,466	4,682
Total other income (expense)	2,541	1,085
Loss from continuing operations before income taxes and gain on sale of joint venture	(8,367)	(43,807)
Income tax provision	2,108	268
Gain on sale of joint venture	0	500
Net loss from continuing operations	(10,475)	(43,575)
Loss from discontinued operations, net of tax	(9,085)	(23,901)
Net loss	(19,560)	(67,476)
Less: Net income attributable to noncontrolling interest	1,426	1,859
Net loss attributable to Ampco-Pittsburgh	$ (20,986)	$ (69,335)
Net loss from continuing operations per share attributable to Ampco-Pittsburgh common shareholders:
Basic	$ (0.95)	$ (3.65)
Diluted	(0.95)	(3.65)
Loss from discontinued operations, net of tax, per share attributable to Ampco-Pittsburgh common shareholders:
Basic	(0.72)	(1.92)
Diluted	(0.72)	(1.92)
Net loss per share attributable to Ampco-Pittsburgh common shareholders:
Basic	(1.67)	(5.57)
Diluted	$ (1.67)	$ (5.57)
Weighted average number of common shares outstanding:
Basic	12,590,000	12,448,000
Diluted	12,590,230	12,447,919