Employee Benefit Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	$ 2,233,079	$ 2,129,058	$ 2,756,803
Assets Measured at NAV	53,876	48,521
Common stocks — mutual funds — equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	318,418	285,103
Assets Measured at NAV	53,876	48,521
Genuine Parts Company common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	209,384	261,869
Assets Measured at NAV	0	0
Other stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	763,451	711,830
Assets Measured at NAV	0	0
Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	38,235	41,076
Assets Measured at NAV	0	0
Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	6,608	8,632
Assets Measured at NAV	0	0
Government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	389,199	344,787
Assets Measured at NAV	0	0
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	436,418	412,896
Assets Measured at NAV	0	0
Asset-backed and mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	10,396	9,925
Assets Measured at NAV	0	0
Convertible Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	1,720	1,159
Assets Measured at NAV	0	0
Other-international
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	45,059	37,304
Assets Measured at NAV	0	0
Municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	14,295	14,442
Assets Measured at NAV	0	0
Options and Futures
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	(104)	35
Assets Measured at NAV	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	1,282,756	1,297,739
Quoted Prices in Active Markets for Identical Assets (Level 1) | Common stocks — mutual funds — equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	264,542	236,582
Quoted Prices in Active Markets for Identical Assets (Level 1) | Genuine Parts Company common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	209,384	261,869
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	763,451	711,830
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	38,235	41,076
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	6,608	8,632
Quoted Prices in Active Markets for Identical Assets (Level 1) | Government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	536	411
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed and mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Convertible Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other-international
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	37,304
Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Options and Futures
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	35
Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	896,446	782,798
Significant Observable Inputs (Level 2) | Common stocks — mutual funds — equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Observable Inputs (Level 2) | Genuine Parts Company common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Observable Inputs (Level 2) | Other stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Observable Inputs (Level 2) | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Observable Inputs (Level 2) | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Observable Inputs (Level 2) | Government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	388,663	344,376
Significant Observable Inputs (Level 2) | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	436,418	412,896
Significant Observable Inputs (Level 2) | Asset-backed and mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	10,396	9,925
Significant Observable Inputs (Level 2) | Convertible Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	1,720	1,159
Significant Observable Inputs (Level 2) | Other-international
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	45,059	0
Significant Observable Inputs (Level 2) | Municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	14,295	14,442
Significant Observable Inputs (Level 2) | Options and Futures
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	(105)	0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	1	0
Significant Unobservable Inputs (Level 3) | Common stocks — mutual funds — equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Genuine Parts Company common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Other stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Asset-backed and mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Convertible Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Other-international
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	0
Significant Unobservable Inputs (Level 3) | Options and Futures
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	$ 1	$ 0