Securities - Amortized Cost and Fair Value of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,065,927	$ 900,235
Gross Unrealized Gains	1,648	15,183
Gross Unrealized Losses	(40,495)	(5,767)
Fair Value	1,027,080	909,651
Interest receivable	3,500	3,300
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	136,695	95,954
Gross Unrealized Gains	41	115
Gross Unrealized Losses	(6,742)	(742)
Fair Value	129,994	95,327
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	58,570	68,599
Gross Unrealized Gains	179	1,749
Gross Unrealized Losses	(256)	0
Fair Value	58,493	70,348
Collateralized mortgage obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	404,626	270,696
Gross Unrealized Gains	179	2,408
Gross Unrealized Losses	(19,203)	(2,810)
Fair Value	385,602	270,294
Residential mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	54,444	57,029
Gross Unrealized Gains	52	392
Gross Unrealized Losses	(4,050)	(628)
Fair Value	50,446	56,793
Commercial mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	340,886	336,918
Gross Unrealized Gains	169	5,969
Gross Unrealized Losses	(10,244)	(1,587)
Fair Value	330,811	341,300
Corporate obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	500	500
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	500	500
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	70,206	70,539
Gross Unrealized Gains	1,028	4,550
Gross Unrealized Losses	0	0
Fair Value	$ 71,234	$ 75,089