Fair Value Measurements - Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	$ 57	$ 28,578
Securities available-for-sale, at fair value	6,780,648	10,694,458
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity warrants		3,555
Agency residential CMOs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	803,309	1,038,134
Private label residential CMOs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	216,103	264,417
Collateralized loan obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	352,290	385,362
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	700,605	2,315,968
Agency commercial MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	976,221	1,688,967
Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	32,647	129,547
SBA securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	23,727	29,644
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	369,461	527,094
U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	696,054	966,898
Private label commercial MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	32,516	450,217
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity warrants	4,001	3,555
Interest rate and economic contracts	4,829	2,509
Securities available-for-sale, at fair value	6,780,648
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity warrants	0	0
Interest rate and economic contracts	0	0
Equity Securities, FV-NI	57	28,578
Securities available-for-sale, at fair value	696,054	966,898
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity warrants	0	0
Interest rate and economic contracts	4,829	2,509
Equity Securities, FV-NI	0	0
Securities available-for-sale, at fair value	6,084,594	9,712,559
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity warrants	4,001	3,555
Interest rate and economic contracts	0	0
Equity Securities, FV-NI	0	0
Securities available-for-sale, at fair value	0	15,001
Fair Value, Measurements, Recurring | Government agency and government-sponsored enterprise pass through securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	2,577,715	2,898,210
Fair Value, Measurements, Recurring | Government agency and government-sponsored enterprise pass through securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Government agency and government-sponsored enterprise pass through securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	2,577,715	2,898,210
Fair Value, Measurements, Recurring | Government agency and government-sponsored enterprise pass through securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Agency residential CMOs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	803,309	1,038,134
Fair Value, Measurements, Recurring | Agency residential CMOs | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Agency residential CMOs | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	803,309	1,038,134
Fair Value, Measurements, Recurring | Agency residential CMOs | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Private label residential CMOs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	216,103	264,417
Fair Value, Measurements, Recurring | Private label residential CMOs | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Private label residential CMOs | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	216,103	264,417
Fair Value, Measurements, Recurring | Private label residential CMOs | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Collateralized loan obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	352,290	385,362
Fair Value, Measurements, Recurring | Collateralized loan obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Collateralized loan obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	352,290	385,362
Fair Value, Measurements, Recurring | Collateralized loan obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	700,605	2,315,968
Fair Value, Measurements, Recurring | Municipal securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Municipal securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	700,605	2,315,968
Fair Value, Measurements, Recurring | Municipal securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Agency commercial MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	976,221	1,688,967
Fair Value, Measurements, Recurring | Agency commercial MBS | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Agency commercial MBS | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	976,221	1,688,967
Fair Value, Measurements, Recurring | Agency commercial MBS | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	32,647	129,547
Fair Value, Measurements, Recurring | Asset-backed securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Asset-backed securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	32,647	129,547
Fair Value, Measurements, Recurring | Asset-backed securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | SBA securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	23,727	29,644
Fair Value, Measurements, Recurring | SBA securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | SBA securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	23,727	29,644
Fair Value, Measurements, Recurring | SBA securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	369,461	527,094
Fair Value, Measurements, Recurring | Corporate debt securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Corporate debt securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	369,461	527,094
Fair Value, Measurements, Recurring | Corporate debt securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	696,054	966,898
Fair Value, Measurements, Recurring | U.S. Treasury securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	696,054	966,898
Fair Value, Measurements, Recurring | U.S. Treasury securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | U.S. Treasury securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Private label commercial MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	32,516	450,217
Fair Value, Measurements, Recurring | Private label commercial MBS | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	0	0
Fair Value, Measurements, Recurring | Private label commercial MBS | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	32,516	435,216
Fair Value, Measurements, Recurring | Private label commercial MBS | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale, at fair value	$ 0	$ 15,001