Securities - Amortized Cost and Fair Value of Debt Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,071,876	$ 1,104,105
Gross Unrealized Gains	14	261
Gross Unrealized Losses	(102,465)	(102,582)
Fair Value	969,425	1,001,784
Interest receivable	3,300	3,700
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	144,858	145,416
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(13,623)	(13,721)
Fair Value	131,235	131,695
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	43,411	43,479
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,546)	(1,668)
Fair Value	41,865	41,811
Collateralized mortgage obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	485,131	482,039
Gross Unrealized Gains	0	203
Gross Unrealized Losses	(56,242)	(53,835)
Fair Value	428,889	428,407
Residential mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	46,958	49,418
Gross Unrealized Gains	2	3
Gross Unrealized Losses	(7,180)	(7,834)
Fair Value	39,780	41,587
Commercial mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	320,993	352,465
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(23,715)	(25,152)
Fair Value	297,278	327,313
Corporate obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	0	500
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	0	500
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	30,525	30,788
Gross Unrealized Gains	12	55
Gross Unrealized Losses	(159)	(372)
Fair Value	$ 30,378	$ 30,471