Investment Securities - Securities Available for Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	$ 43	$ 163,035
Gross Unrealized Losses	878,656	72,095
Fair Value	5,891,328	10,694,458
Debt Securities, Available-for-sale, Amortized Cost, Total	6,769,941	10,603,518
Agency residential MBS
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	8,866
Gross Unrealized Losses	469,436	32,649
Fair Value	2,291,234	2,898,210
Debt Securities, Available-for-sale, Amortized Cost, Total	2,760,670	2,921,993
Agency commercial MBS
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	8	37,664
Gross Unrealized Losses	79,869	9,213
Fair Value	807,920	1,688,967
Debt Securities, Available-for-sale, Amortized Cost, Total	887,781	1,660,516
Agency residential CMOs
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	22,288
Gross Unrealized Losses	68,079	5,870
Fair Value	736,482	1,038,134
Debt Securities, Available-for-sale, Amortized Cost, Total	804,561	1,021,716
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	1,641
Gross Unrealized Losses	107,693	8,298
Fair Value	663,389	966,898
Debt Securities, Available-for-sale, Amortized Cost, Total	771,082	973,555
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	35	75,192
Gross Unrealized Losses	64,967	7,973
Fair Value	415,199	2,315,968
Debt Securities, Available-for-sale, Amortized Cost, Total	480,131	2,248,749
Collateralized loan obligations
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	396
Gross Unrealized Losses	11,582	444
Fair Value	353,762	385,362
Debt Securities, Available-for-sale, Amortized Cost, Total	365,344	385,410
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	13,774
Gross Unrealized Losses	28,904	757
Fair Value	345,542	527,094
Debt Securities, Available-for-sale, Amortized Cost, Total	374,446	514,077
Private label residential CMOs
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	1,857
Gross Unrealized Losses	43,824	3,291
Fair Value	197,955	264,417
Debt Securities, Available-for-sale, Amortized Cost, Total	241,779	265,851
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	484
Gross Unrealized Losses	498	324
Fair Value	32,022	129,547
Debt Securities, Available-for-sale, Amortized Cost, Total	32,520	129,387
Private label commercial MBS
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	147
Gross Unrealized Losses	2,456	3,244
Fair Value	29,178	450,217
Debt Securities, Available-for-sale, Amortized Cost, Total	31,634	453,314
SBA securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	726
Gross Unrealized Losses	1,348	32
Fair Value	18,645	29,644
Debt Securities, Available-for-sale, Amortized Cost, Total	$ 19,993	$ 28,950

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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