Securities - Amortized Cost to Fair Value of Available for Sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,159,544	$ 1,187,778
Gross Unrealized Gains	21,512	41,433
Gross Unrealized Losses	(5,737)	(4,128)
Estimated Fair Value	1,175,319	1,225,083
U.S. government sponsored enterprise debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	443,892	640,796
Gross Unrealized Gains	9,319	21,546
Gross Unrealized Losses	(2,438)	(1,007)
Estimated Fair Value	450,773	661,335
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	348,576	292,033
Gross Unrealized Gains	10,143	10,787
Gross Unrealized Losses	(929)	(1,106)
Estimated Fair Value	357,790	301,714
U.S. government agency debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	362,323	202,135
Gross Unrealized Gains	1,953	4,458
Gross Unrealized Losses	(2,370)	(2,015)
Estimated Fair Value	361,906	204,578
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,501	2,505
Gross Unrealized Gains	1	7
Gross Unrealized Losses	0	0
Estimated Fair Value	2,502	2,512
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,252	50,309
Gross Unrealized Gains	96	4,635
Gross Unrealized Losses	0	0
Estimated Fair Value	2,348	54,944
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	654,700	647,000
Estimated Fair Value	661,300	666,700
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	123,500	123,900
Estimated Fair Value	$ 123,800	$ 128,400