Fair Value Measurements - Other Real Estate Owned and Repossessed Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total Gains (Losses) | Installment and Other Consumer
Fair Value Measurements
Gains (losses) on impaired loans	$ (16)		$ (16)
Nonrecurring | Fair value
Fair Value Measurements
Impaired loans	2,830	$ 15,992	2,830	$ 15,992
Other real estate and repossessed assets	6,429	9,155	6,429	9,155
Nonrecurring | Fair value | Commercial, financial, & agricultural
Fair Value Measurements
Impaired loans	50		50
Nonrecurring | Fair value | Real estate mortgage − residential
Fair Value Measurements
Impaired loans	120		120
Nonrecurring | Fair value | Real estate mortgage − commercial
Fair Value Measurements
Impaired loans	2,660		2,660
Nonrecurring | Fair value | Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans		15,992		15,992
Nonrecurring | Fair value | Installment and Other Consumer
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Total Gains (Losses)
Fair Value Measurements
Gains (losses) on impaired loans	(36)	(2)	(41)	(25)
Gains (losses) on other real estate and repossessed assets	(1,792)	23	(1,783)	(22)
Nonrecurring | Total Gains (Losses) | Commercial, financial, & agricultural
Fair Value Measurements
Gains (losses) on impaired loans			0
Nonrecurring | Total Gains (Losses) | Real estate mortgage − residential
Fair Value Measurements
Gains (losses) on impaired loans			0
Nonrecurring | Total Gains (Losses) | Real estate mortgage − commercial
Fair Value Measurements
Gains (losses) on impaired loans	(20)		(25)
Nonrecurring | Total Gains (Losses) | Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Gains (losses) on impaired loans		(2)		(25)
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value
Fair Value Measurements
Impaired loans	0	0	0	0
Other real estate and repossessed assets	0	0	0	0
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value | Commercial, financial, & agricultural
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value | Real estate mortgage − residential
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value | Real estate mortgage − commercial
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value | Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans		0		0
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value | Installment and Other Consumer
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Other Observable Inputs (Level 2) | Fair value
Fair Value Measurements
Impaired loans	0	0	0	0
Other real estate and repossessed assets	0	0	0	0
Nonrecurring | Other Observable Inputs (Level 2) | Fair value | Commercial, financial, & agricultural
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Other Observable Inputs (Level 2) | Fair value | Real estate mortgage − residential
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Other Observable Inputs (Level 2) | Fair value | Real estate mortgage − commercial
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Other Observable Inputs (Level 2) | Fair value | Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans		0		0
Nonrecurring | Other Observable Inputs (Level 2) | Fair value | Installment and Other Consumer
Fair Value Measurements
Impaired loans	0		0
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value
Fair Value Measurements
Impaired loans	2,830	15,992	2,830	15,992
Other real estate and repossessed assets	6,429	9,155	6,429	9,155
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Commercial, financial, & agricultural
Fair Value Measurements
Impaired loans	50		50
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Real estate mortgage − residential
Fair Value Measurements
Impaired loans	120		120
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Real estate mortgage − commercial
Fair Value Measurements
Impaired loans	2,660		2,660
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans		$ 15,992		$ 15,992
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Installment and Other Consumer
Fair Value Measurements
Impaired loans	$ 0		$ 0