Schedule II - Valuation and Qualifying Accounts (Parenthetical) (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($)
Valuation And Qualifying Accounts [Abstract]
Decrease in valuation allowance	$ 1,046
Increase in valuation allowance	$ 11,000

Increase in valuation allowance discontinued operation.

No definition available.

Name:	ap_IncreaseInValuationAllowanceDiscontinuedOperation
Namespace Prefix:	ap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration