Credit Facilities - Additional Information (Detail) (USD $)	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
Borrowings subject to variable rates	$ 264,658,000	$ 0
Weighted average interest rate on outstanding borrowings	2.82%	4.01%
Unsecured revolving line of credit facility	850,000,000
Line of credit facility, interest rate at period end	0.92%
Line of credit facility amount of option to increase additional borrowing	350,000,000
Outstanding line of credit	264,658,000	0
Unused letter of credit outstanding due to workers' compensation and insurance reserve	$ 61,617,000	$ 61,119,000
Line of credit facility, maturity date	September 2017

Borrowings subject to variable rates

No definition available.

Name:	gpc_BorrowingsSubjectToVariableRates
Namespace Prefix:	gpc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facilities expiration date

+ References

No definition available.

+ Details

Name:	gpc_LineOfCreditFacilitiesExpirationDate
Namespace Prefix:	gpc_
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility amount of option to increase additional borrowings.

+ References

No definition available.

+ Details

Name:	gpc_LineOfCreditFacilityAmountOfOptionToIncreaseAdditionalBorrowings
Namespace Prefix:	gpc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The effective interest rate at the end of the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant