Name:	gpc_AmountsRecognizedInAccumulatedOtherComprehensiveLossTableTableTextBlock
Namespace Prefix:	gpc_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Schedule of Assumptions Used To Measure Net Periodic Benefit Costs [Table Text Block]

No definition available.

Name:	gpc_ScheduleOfAssumptionsUsedToMeasureNetPeriodicBenefitCostsTableTextBlock
Namespace Prefix:	gpc_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Summary of Allocation of Plan Assets [Table Text Block]

No definition available.

Name:	gpc_SummaryOfAllocationOfPlanAssetsTableTextBlock
Namespace Prefix:	gpc_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

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

Tabular disclosure of benefit obligation and plan assets of defined benefit plan with accumulated benefit obligation in excess of plan assets.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2417-114920

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2417-114920

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Name:	us-gaap_ScheduleOfAccumulatedBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the amounts that are recognized in the balance sheet (or statement of financial position) for pension plans and/or other employee benefit plans, showing separately the assets and current and noncurrent liabilities (if applicable) recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of assumption used to determine benefit obligation and net periodic benefit cost of defined benefit plan. Includes, but is not limited to, discount rate, rate of compensation increase, expected long-term rate of return on plan assets and interest crediting rate.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfAssumptionsUsedTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of benefit obligation and plan assets for defined benefit pension plan with projected benefit obligation in excess of plan assets.

Name:	us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the reconciliation of beginning and ending balances of the fair value of plan assets of pension plans and/or other employee benefit plans showing separately, if applicable, the effects during the period attributable to each of the following: actual return on plan assets, foreign currency exchange rate changes, contributions by the employer, contributions by plan participants, benefits paid, business combinations, divestitures, and settlements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the change in the benefit obligation of pension plans and/or other employee benefit plans from the beginning to the end of the period, showing separately, if applicable, the effects of the following: service cost, interest cost, contributions by plan participants, actuarial gains and losses, foreign currency exchange rate changes, benefits paid, plan amendments, business combinations, divestitures, curtailments, settlements, and special and contractual termination benefits.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the changes in plan assets and benefit obligations recognized in other comprehensive income (loss) during the period.

No definition available.

Name:	us-gaap_ScheduleOfDefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920