Fair Value Measurements - Other Real Estate Owned and Repossessed Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Total Gains (Losses) | Installment and Other Consumer
Fair Value Measurements
Gains (losses) on impaired loans		$ (6)		$ (6)
Nonrecurring | Fair value
Fair Value Measurements
Impaired loans	$ 15,992	26,755	$ 15,992	26,755
Other real estate and repossessed assets	9,155	11,938	9,155	11,938
Nonrecurring | Fair value | Commercial, Financial, & Agricultural
Fair Value Measurements
Impaired loans		3,976		3,976
Nonrecurring | Fair value | Real estate construction − residential & Real estate mortgage − residential | Mortgage
Fair Value Measurements
Impaired loans		359		359
Nonrecurring | Fair value | Real estate construction − commercial & Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans	15,992	22,420	15,992	22,420
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	(2)	(11)	(25)	(34)
Gains (losses) on other real estate owned and repossessed assets	23	14	(22)	(59)
Nonrecurring | Total Gains (Losses) | Commercial, Financial, & Agricultural
Fair Value Measurements
Gains (losses) on impaired loans		0		0
Nonrecurring | Total Gains (Losses) | Real estate construction − residential & Real estate mortgage − residential | Mortgage
Fair Value Measurements
Gains (losses) on impaired loans		(3)		(3)
Nonrecurring | Total Gains (Losses) | Real estate construction − commercial & Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Gains (losses) on impaired loans	(2)	(2)	(25)	(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 construction − residential & Real estate mortgage − residential | Mortgage
Fair Value Measurements
Impaired loans		0		0
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value | Real estate construction − commercial & Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans	0	0	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 construction − residential & Real estate mortgage − residential | Mortgage
Fair Value Measurements
Impaired loans		0		0
Nonrecurring | Other Observable Inputs (Level 2) | Fair value | Real estate construction − commercial & Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans	0	0	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	15,992	26,755	15,992	26,755
Other real estate and repossessed assets	9,155	11,938	9,155	11,938
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Commercial, Financial, & Agricultural
Fair Value Measurements
Impaired loans		3,976		3,976
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Real estate construction − residential & Real estate mortgage − residential | Mortgage
Fair Value Measurements
Impaired loans		359		359
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Real estate construction − commercial & Real estate mortgage − commercial | Mortgage
Fair Value Measurements
Impaired loans	$ 15,992	22,420	$ 15,992	22,420
Nonrecurring | Significant Unobservable Inputs (Level 3) | Fair value | Installment and Other Consumer
Fair Value Measurements
Impaired loans		$ 0		$ 0