Fair value of assets provided as collateral.

No definition available.

Name:	ap_FairValueOfAssetsHeldAsCollateralRelatedToForwardExchangeContracts
Namespace Prefix:	ap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of subsidiaries who have committed to purchase a portion of their anticipated natural gas requirements in advance.

+ References

No definition available.

+ Details

Name:	ap_NumberOfSubsidiariesPurchasedCommitmentsForNaturalGasUsage
Namespace Prefix:	ap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of anticipated requirements which are covered by cash flow hedges.

+ References

No definition available.

+ Details

Name:	ap_PercentageOfAnticipatedPurchasesHedged
Namespace Prefix:	ap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of anticipated requirements which are covered by purchase commitments.

+ References

No definition available.

+ Details

Name:	ap_PercentageOfPurchaseCommitmentsCoveringAnticipatedNaturalGasUsageApproximate
Namespace Prefix:	ap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period covered by cash flow hedges.

+ References

No definition available.

+ Details

Name:	ap_PeriodForHedgedPurchases
Namespace Prefix:	ap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Dollar value of anticipated natural gas requirements which are covered by purchase commitments.

+ References

No definition available.

+ Details

Name:	ap_PurchaseCommitmentAmountOfAnticipatedNaturalGasUsage
Namespace Prefix:	ap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Purchase commitments covering period anticipated usage description.

+ References

No definition available.

+ Details

Name:	ap_PurchaseCommitmentsCoveringPeriodAnticipatedUsageDescription
Namespace Prefix:	ap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Cost of natural gas purchased and associated transportation and storage costs during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_CostOfNaturalGasPurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of the hedged item as of the balance sheet date related to the derivative. For example, the hedged balance on a debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeAmountOfHedgedItem
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30690-110894

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30700-110894

+ Details

Name:	us-gaap_ForeignCurrencyTransactionGainLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DerivativeByNatureAxis=ap_AluminumPurchasesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeByNatureAxis=ap_CopperPurchasesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeByNatureAxis=ap_ForeignCurrencySalesContractFairValueHedgesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Derivative Instruments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Customer	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Anticipated foreign-denominated sales hedge	$ 16,126us-gaap_DerivativeAmountOfHedgedItem
Percentage of purchase commitments covering anticipated natural gas usage	32.00%
Purchase commitment amount of anticipated natural gas usage	2,691
Number of subsidiaries purchased commitments for natural gas usage	1
Purchase commitments covering period anticipated usage, Description	Through 2017 for one of its subsidiaries
Purchase of natural gas	2,190us-gaap_CostOfNaturalGasPurchases	2,694us-gaap_CostOfNaturalGasPurchases	4,314us-gaap_CostOfNaturalGasPurchases
(Losses) gains on foreign exchange transactions included in other income (expense)	(488)	(227)	107
Foreign Currency Sales Contract - Fair Value Hedges [Member]
Derivative [Line Items]
Fair value of assets held as collateral related to forward exchange contracts	800
Copper Purchases [Member]
Derivative [Line Items]
Percentage of anticipated purchases hedged	57.00%
Time period for hedged purchases	9 months
Copper Purchases [Member] \| Cash Flow Hedges [Member]
Derivative [Line Items]
Anticipated purchases, hedged	2,700
Aluminum Purchases [Member]
Derivative [Line Items]
Percentage of anticipated purchases hedged	38.00%
Time period for hedged purchases	6 months
Aluminum Purchases [Member] \| Cash Flow Hedges [Member]
Derivative [Line Items]
Anticipated purchases, hedged	$ 500