Investment Securities - Securities Available for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 2,699,255	$ 5,654,617
Debt Securities, Available-for-Sale, Allowance for Credit Loss	(199)	0
Debt Securities, Available-for-Sale, Net Carrying Amount	2,699,056	5,654,617
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	262	6
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(352,454)	(811,136)
(amortized cost of $2,699,255 and $5,654,617, respectively)	2,346,864	4,843,487
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	1,388,801	2,685,038
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	1,388,801	2,685,038
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(201,192)	(442,996)
(amortized cost of $2,699,255 and $5,654,617, respectively)	1,187,609	2,242,042
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	4,965	771,145
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	4,965	771,145
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	3	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	0	(101,075)
(amortized cost of $2,699,255 and $5,654,617, respectively)	4,968	670,070
Government agency and government-sponsored enterprise pass through securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	268,639	549,492
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	268,639	549,492
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(15,333)	(61,886)
(amortized cost of $2,699,255 and $5,654,617, respectively)	253,306	487,606
Government agency and government-sponsored enterprise collateralized mortgage obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	320,984	517,174
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	320,984	517,174
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(36,650)	(60,111)
(amortized cost of $2,699,255 and $5,654,617, respectively)	284,334	457,063
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	29,192	399,724
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	29,192	399,724
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(1,109)	(60,398)
(amortized cost of $2,699,255 and $5,654,617, respectively)	28,083	339,326
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	327,426	344,767
Debt Securities, Available-for-Sale, Allowance for Credit Loss	(199)	0
Debt Securities, Available-for-Sale, Net Carrying Amount	327,227	344,767
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	259	6
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(60,254)	(32,868)
(amortized cost of $2,699,255 and $5,654,617, respectively)	267,232	311,905
Private Label Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	193,071	207,123
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	193,071	207,123
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(34,659)	(40,399)
(amortized cost of $2,699,255 and $5,654,617, respectively)	158,412	166,724
Collateralized Loan Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	109,168	109,159
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	109,168	109,159
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(752)	(6,898)
(amortized cost of $2,699,255 and $5,654,617, respectively)	108,416	102,261
Mortgage-backed Securities, Issued by Private Enterprises
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	22,126	28,903
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	22,126	28,903
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(1,313)	(2,076)
(amortized cost of $2,699,255 and $5,654,617, respectively)	20,813	26,827
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	20,241	23,568
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	20,241	23,568
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(289)	(1,155)
(amortized cost of $2,699,255 and $5,654,617, respectively)	19,952	22,413
SBA asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	14,642	18,524
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-Sale, Net Carrying Amount	14,642	18,524
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax	(903)	(1,274)
(amortized cost of $2,699,255 and $5,654,617, respectively)	$ 13,739	$ 17,250