Accumulated Other Comprehensive Loss - Net Changes and Ending Balances for Various Components of Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022		Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	$ 112,134	[2]	$ 96,493
Net change	[1]	(4,033)		13,826	[3]
Ending Balance	[1]	113,396		112,134	[2]
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(14,322)		(11,371)
Net change		(11,848)		(2,951)
Ending Balance		(26,170)		(14,322)
Unrecognized Components of Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(40,563)		(57,652)
Net change		7,940		17,089
Ending Balance		(32,623)		(40,563)
Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		277		589
Net change		(125)		(312)
Ending Balance		152		277
Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		498		261
Net change		(727)		237
Ending Balance		(229)		498
Accumulated Other Comprehensive Loss Attributable to Ampco-Pittsburgh [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(55,106)		(68,695)
Net change		(3,306)		13,589
Ending Balance		(58,412)		(55,106)
Total Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(54,608)		(68,434)
Net change		(4,033)		13,826
Ending Balance		$ (58,641)		$ (54,608)

[1] Retained deficit as of January 1, 2021, net loss for 2021 and retained deficit as of December 31, 2021 were adjusted to include inventory costs using the FIFO basis of costing. See Note 2.   See Notes to Consolidated Financial Statements.

[2] The December 31, 2021 balance sheet was adjusted to present inventory using the FIFO basis of costing. See Note 2.

[3] Net loss for 2021 and subsequent subtotals and totals were adjusted to include inventory costs using the FIFO basis of costing. See Note 2