Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 03, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Trading Symbol	AP
Entity Registrant Name	AMPCO PITTSBURGH CORP
Entity Central Index Key	0000006176
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		12,361,486