General (Policies)	3 Months Ended
General (Policies)	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Accounting	The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with the instructions to Form 10-Q and therefore do not include all information and footnotes required by accounting principles generally accepted in the U.S. (“U.S. GAAP”) for complete financial statements. Except as disclosed herein, there have been no material changes in the information disclosed in the Notes to the Consolidated Financial Statements included in the Annual Report on Form 10-K of Genuine Parts Company (the “Company,” “we,” “our,” “us,” or “its”) for the year ended December 31, 2023. Accordingly, the unaudited Condensed Consolidated Financial Statements and related disclosures herein should be read in conjunction with our 2023 Annual Report on Form 10-K.
Use of Estimates	The preparation of interim financial statements requires management to make estimates and assumptions that affect the amounts reported in the unaudited Condensed Consolidated Financial Statements. Specifically, we make estimates and assumptions in our unaudited Condensed Consolidated Financial Statements for inventory adjustments, the accrual of bad debts, credit losses on guaranteed loans, customer sales returns, and volume incentives earned, among others. Inventory adjustments (including adjustments for a majority of inventories that are valued under the last-in, first-out (“LIFO”) method) are accrued on an interim basis and adjusted in the fourth quarter based on the annual book to physical inventory adjustment and LIFO valuation. Reserves for bad debts, credit losses on guaranteed loans and customer sales returns are estimated and accrued on an interim basis based on a consideration of historical experience, current conditions, and reasonable and supportable forecasts. Volume incentives are estimated based upon cumulative and projected purchasing levels. In the opinion of management, all adjustments necessary for a fair presentation of our financial results for the interim periods have been made. These adjustments are of a normal recurring nature.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Changes to U.S. GAAP are established by the Financial Accounting Standards Board (“FASB”) in the form of Accounting Standards Updates (“ASU”) to the FASB Accounting Standards Codification (“ASC”). We consider the applicability and impact of all ASUs and any not listed below were assessed and determined to not be applicable or are expected to have an immaterial impact on our Condensed Consolidated Financial Statements. Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This standard requires disclosures of significant segment expenses that are regularly provided to the chief operating decision maker ("CODM") and included within each reported measure of segment profit or loss, an amount and description of other segment items by reportable segment, and all annual disclosures currently required by Topic 280 to be included in interim periods. The guidance is effective for our Annual Report on Form 10-K for the year ended December 31, 2024, and subsequent interim periods, with early adoption permitted. We are currently evaluating the impact of adopting this standard on our financial statements and disclosures. Income Taxes (Topic 740): Improvements to Income Tax Disclosures In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. The standard requires disclosure of specific categories in the rate reconciliation and additional information for reconciling items, income before tax expense disaggregated between domestic and foreign, income tax expense disaggregated by federal, state and foreign, as well as further information on income taxes paid. The guidance is effective for our Annual Report on Form 10-K for the year ended December 31, 2025, with early adoption permitted. The guidance should be applied on a prospective basis, with retrospective application permitted. We are currently evaluating the impact of adopting this standard on our financial statements and disclosures.
Derivatives and Hedging	Derivatives and Hedging We are exposed to various risks arising from business operations and market conditions, including fluctuations in certain foreign currencies. We use derivative and non-derivative instruments as risk management tools to mitigate the potential impact of foreign exchange rate risks. The objective of using these tools is to reduce fluctuations in our earnings and cash flows associated with changes in these rates. Derivative instruments are recognized in the Condensed Consolidated Balance Sheets at fair value and are designated as Level 2 in the fair value hierarchy. They are valued using inputs other than quoted prices, such as foreign exchange rates and yield curves.
Fair Value of Financial Instruments	Our valuation technique is based primarily on prices and other relevant information generated by observable transactions involving identical or comparable assets or liabilities.
Guarantees	We guarantee the borrowings of certain independently controlled automotive parts stores and businesses (“independents”) and certain other affiliates in which we have a noncontrolling equity ownership interest (“affiliates”). While such borrowings of the independents and affiliates are outstanding, we are required to maintain compliance with certain covenants. As of March 31, 2024, we were in compliance with all such covenants. As of March 31, 2024, there are no material guaranteed loans for which the borrower is experiencing financial difficulty and recovery is expected to be provided substantially through the operation or sale of the collateral.
Supply Chain Finance Programs	Supply Chain Finance Programs Several global financial institutions offer voluntary supply chain finance (“SCF”) programs which enable our suppliers (generally those that grant extended terms), at their sole discretion, to sell their receivables from us to these financial institutions on a non-recourse basis at a rate that takes advantage of our credit rating and may be beneficial to them. We and our suppliers agree on commercial terms for the goods and services we procure, including prices, quantities and payment terms, regardless of whether the supplier elects to participate in the SCF program. Our current payment terms with the majority of our suppliers range from 30 to 360 days. The suppliers sell goods or services, as applicable, to us and they issue the associated invoices to us based on the agreed-upon contractual terms. Then, if they are participating in the SCF program, our suppliers, at their sole discretion, determine which invoices, if any, they want to sell to the financial institutions. In turn, we direct payment to the financial institutions, rather than the suppliers, for the invoices sold to the financial institutions. No guarantees are provided by us or any of our subsidiaries on third-party performance under the SCF program; however, we guarantee the payment by our subsidiaries to the financial institutions participating in the SCF program for the applicable invoices. We have no economic interest in a supplier’s decision to participate in the SCF program, and we have no direct financial relationship with the financial institutions, as it relates to the SCF program. Accordingly, amounts due to our suppliers that elected to participate in the SCF program are included in the line item accounts payable in our Condensed Consolidated Balance Sheets. All activity related to amounts due to suppliers that elected to participate in the SCF program is reflected in cash flows from operating activities in our Condensed Consolidated Statement of Cash Flows.
Earnings Per Share	Earnings Per Share We calculate basic earnings per share by dividing net income by the weighted average number of common shares outstanding. Certain outstanding options are not included in the diluted earnings per share calculation because their inclusion would have been anti-dilutive.