Investment Securities - Securities Available for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	$ 5,157	$ 163,035
Gross Unrealized Losses	595,510	72,095
Fair Value	6,780,648	10,694,458
Debt Securities, Available-for-sale, Amortized Cost, Total	7,371,001	10,603,518
Agency residential MBS
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	901	8,866
Gross Unrealized Losses	321,670	32,649
Fair Value	2,577,715	2,898,210
Debt Securities, Available-for-sale, Amortized Cost, Total	2,898,484	2,921,993
Agency commercial MBS
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	849	37,664
Gross Unrealized Losses	44,711	9,213
Fair Value	976,221	1,688,967
Debt Securities, Available-for-sale, Amortized Cost, Total	1,020,083	1,660,516
Agency residential CMOs
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	109	22,288
Gross Unrealized Losses	41,308	5,870
Fair Value	803,309	1,038,134
Debt Securities, Available-for-sale, Amortized Cost, Total	844,508	1,021,716
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	3,219	75,192
Gross Unrealized Losses	45,459	7,973
Fair Value	700,605	2,315,968
Debt Securities, Available-for-sale, Amortized Cost, Total	742,845	2,248,749
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	1,641
Gross Unrealized Losses	74,965	8,298
Fair Value	696,054	966,898
Debt Securities, Available-for-sale, Amortized Cost, Total	771,019	973,555
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	75	13,774
Gross Unrealized Losses	19,080	757
Fair Value	369,461	527,094
Debt Securities, Available-for-sale, Amortized Cost, Total	388,466	514,077
Collateralized loan obligations
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	396
Gross Unrealized Losses	13,064	444
Fair Value	352,290	385,362
Debt Securities, Available-for-sale, Amortized Cost, Total	365,354	385,410
Private label residential CMOs
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	1,857
Gross Unrealized Losses	32,052	3,291
Fair Value	216,103	264,417
Debt Securities, Available-for-sale, Amortized Cost, Total	248,155	265,851
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	4	484
Gross Unrealized Losses	711	324
Fair Value	32,647	129,547
Debt Securities, Available-for-sale, Amortized Cost, Total	33,354	129,387
Private label commercial MBS
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	147
Gross Unrealized Losses	1,895	3,244
Fair Value	32,516	450,217
Debt Securities, Available-for-sale, Amortized Cost, Total	34,411	453,314
SBA securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	0	726
Gross Unrealized Losses	595	32
Fair Value	23,727	29,644
Debt Securities, Available-for-sale, Amortized Cost, Total	$ 24,322	$ 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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