Employee Benefit Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	$ 2,129,058	$ 2,756,803	$ 2,545,359
Assets Measured at NAV	48,521	64,669
Common stocks — mutual funds — equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	285,103	388,591
Assets Measured at NAV	48,521	64,669
Genuine Parts Company common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	261,869	210,510
Assets Measured at NAV	0	0
Other stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	711,830	971,020
Assets Measured at NAV	0	0
Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	41,076	46,815
Assets Measured at NAV	0	0
Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	8,632	22,084
Assets Measured at NAV	0	0
Government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	344,787	425,877
Assets Measured at NAV	0	0
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	412,896	598,216
Assets Measured at NAV	0	0
Asset-backed and mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	9,925	12,894
Assets Measured at NAV	0	0
Convertible Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	1,159
Assets Measured at NAV	0
Other-international
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	37,304	61,008
Assets Measured at NAV	0	0
Municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	14,442	19,621
Assets Measured at NAV	0	0
Options and Futures
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	35
Assets Measured at NAV	0
Cash surrender value of life insurance policies
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets		167
Assets Measured at NAV		0
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	1,297,739	1,625,164
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	236,582	323,922
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	261,869	210,510
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other stocks
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	711,830	971,020
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	41,076	46,815
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	8,632	22,084
Quoted Prices in Active Markets for Identical Assets (Level 1) | Government bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	411	4,513
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
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other-international
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	37,304	46,133
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	35
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash surrender value of life insurance policies
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets		167
Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	782,798	1,066,970
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	344,376	421,364
Significant Observable Inputs (Level 2) | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	412,896	598,216
Significant Observable Inputs (Level 2) | Asset-backed and mortgage-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	9,925	12,894
Significant Observable Inputs (Level 2) | Convertible Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	1,159
Significant Observable Inputs (Level 2) | Other-international
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	14,875
Significant Observable Inputs (Level 2) | Municipal bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	14,442	19,621
Significant Observable Inputs (Level 2) | Options and Futures
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0
Significant Observable Inputs (Level 2) | Cash surrender value of life insurance policies
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets		0
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets	0	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
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	$ 0
Significant Unobservable Inputs (Level 3) | Cash surrender value of life insurance policies
Defined Benefit Plan Disclosure [Line Items]
Fair value of assets		$ 0