Investment Securities - Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Estimated Fair Value
Less Than 12 Months	$ 38,116	$ 64,117
12 Months or More	3,949	119,894
Total	42,065	184,011
Unrealized Losses
Less Than 12 Months	(143)	(331)
12 Months or More	(271)	(1,927)
Total	(414)	(2,258)
State, county and municipal securities
Estimated Fair Value
Less Than 12 Months	8,282	3,257
12 Months or More	0	0
Total	8,282	3,257
Unrealized Losses
Less Than 12 Months	(65)	(54)
12 Months or More	0	0
Total	(65)	(54)
Corporate debt securities
Estimated Fair Value
Less Than 12 Months	999	0
12 Months or More	0	784
Total	999	784
Unrealized Losses
Less Than 12 Months	(1)	0
12 Months or More	0	(16)
Total	(1)	(16)
U.S. agency
Estimated Fair Value
Less Than 12 Months	28,835	60,860
12 Months or More	3,949	119,110
Total	32,784	179,970
Unrealized Losses
Less Than 12 Months	(77)	(277)
12 Months or More	(271)	(1,911)
Total	$ (348)	$ (2,188)