Investment Securities - Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Estimated Fair Value
Less Than 12 Months	$ 688,212	$ 38,116
12 Months or More	27,099	3,949
Total	715,311	42,065
Unrealized Losses
Less Than 12 Months	(11,044)	(143)
12 Months or More	(865)	(271)
Total	(11,909)	(414)
U.S. treasury securities
Estimated Fair Value
Less Than 12 Months	87,302
12 Months or More	0
Total	87,302
Unrealized Losses
Less Than 12 Months	(1,087)
12 Months or More	0
Total	(1,087)
U.S. agency
Estimated Fair Value
Less Than 12 Months	10,969
12 Months or More	0
Total	10,969
Unrealized Losses
Less Than 12 Months	(140)
12 Months or More	0
Total	(140)
State, county and municipal securities
Estimated Fair Value
Less Than 12 Months	180,551	8,282
12 Months or More	5,970	0
Total	186,521	8,282
Unrealized Losses
Less Than 12 Months	(3,131)	(65)
12 Months or More	(225)	0
Total	(3,356)	(65)
Corporate debt securities
Estimated Fair Value
Less Than 12 Months	31,977	999
12 Months or More	0	0
Total	31,977	999
Unrealized Losses
Less Than 12 Months	(265)	(1)
12 Months or More	0	0
Total	(265)	(1)
Mortgage-backed securities
Estimated Fair Value
Less Than 12 Months	377,413	28,835
12 Months or More	21,129	3,949
Total	398,542	32,784
Unrealized Losses
Less Than 12 Months	(6,421)	(77)
12 Months or More	(640)	(271)
Total	$ (7,061)	$ (348)