Securities - Schedule of Available-for-sale and Held-to-maturity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
AFS debt securities:
Amortized Cost	$ 6,879,225	$ 10,087,179
Gross Unrealized Gains		51,025
Gross Unrealized Losses		(172,851)
Fair Value	6,034,993	9,965,353
HTM debt securities
Amortized Cost	3,001,868	0
Fair Value	2,455,171
Total debt securities
Amortized Cost	9,881,093
Gross Unrealized Gains	498
Gross Unrealized Losses	(1,391,427)
Fair Value	8,490,164
Debt securities available for sale
AFS debt securities:
Amortized Cost	6,879,225
Gross Unrealized Gains	498
Gross Unrealized Losses	(844,730)
Fair Value	6,034,993
Held-to-Maturity Securities
HTM debt securities
Amortized Cost	3,001,868
Gross Unrealized Gains	0
Gross Unrealized Losses	(546,697)
Fair Value	2,455,171
U.S. Treasury securities
AFS debt securities:
Amortized Cost	676,306	1,049,238
Gross Unrealized Gains		130
Gross Unrealized Losses		(16,687)
Fair Value		1,032,681
U.S. Treasury securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	676,306
Gross Unrealized Gains	0
Gross Unrealized Losses	(70,103)
Fair Value	606,203
U.S. Treasury securities | Held-to-Maturity Securities
HTM debt securities
Amortized Cost	524,081
Gross Unrealized Gains	0
Gross Unrealized Losses	(52,612)
Fair Value	471,469
U.S. government agency and U.S. government-sponsored enterprise debt securities
AFS debt securities:
Amortized Cost	517,806	1,333,984
Gross Unrealized Gains		2,697
Gross Unrealized Losses		(34,710)
Fair Value		1,301,971
U.S. government agency and U.S. government-sponsored enterprise debt securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	517,806
Gross Unrealized Gains	67
Gross Unrealized Losses	(56,266)
Fair Value	461,607
U.S. government agency and U.S. government-sponsored enterprise debt securities | Held-to-Maturity Securities
HTM debt securities
Amortized Cost	998,972
Gross Unrealized Gains	0
Gross Unrealized Losses	(209,560)
Fair Value	789,412
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
AFS debt securities:
Amortized Cost		1,242,043
Gross Unrealized Gains		15,791
Gross Unrealized Losses		(28,854)
Fair Value		1,228,980
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	577,392
Gross Unrealized Gains	0
Gross Unrealized Losses	(77,123)
Fair Value	500,269
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities | Held-to-Maturity Securities
HTM debt securities
Amortized Cost	506,965
Gross Unrealized Gains	0
Gross Unrealized Losses	(98,566)
Fair Value	408,399
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
AFS debt securities:
Amortized Cost		2,968,789
Gross Unrealized Gains		8,629
Gross Unrealized Losses		(49,135)
Fair Value		2,928,283
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	2,011,054
Gross Unrealized Gains	41
Gross Unrealized Losses	(248,900)
Fair Value	1,762,195
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities | Held-to-Maturity Securities
HTM debt securities
Amortized Cost	782,141
Gross Unrealized Gains	0
Gross Unrealized Losses	(148,230)
Fair Value	633,911
Municipal securities:
AFS debt securities:
Amortized Cost	303,884	519,381
Gross Unrealized Gains		10,065
Gross Unrealized Losses		(6,288)
Fair Value		523,158
Municipal securities: | Debt securities available for sale
AFS debt securities:
Amortized Cost	303,884
Gross Unrealized Gains	3
Gross Unrealized Losses	(46,788)
Fair Value	257,099
Municipal securities: | Held-to-Maturity Securities
HTM debt securities
Amortized Cost	189,709
Gross Unrealized Gains	0
Gross Unrealized Losses	(37,729)
Fair Value	151,980
Non-agency commercial mortgage-backed Securities
AFS debt securities:
Amortized Cost		498,920
Gross Unrealized Gains		3,000
Gross Unrealized Losses		(5,477)
Fair Value		496,443
Non-agency commercial mortgage-backed Securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	447,512
Gross Unrealized Gains	213
Gross Unrealized Losses	(49,396)
Fair Value	398,329
Non-agency residential mortgage-backed Securities
AFS debt securities:
Amortized Cost		889,937
Gross Unrealized Gains		971
Gross Unrealized Losses		(8,977)
Fair Value		881,931
Non-agency residential mortgage-backed Securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	762,202
Gross Unrealized Gains	0
Gross Unrealized Losses	(112,978)
Fair Value	649,224
Corporate debt securities
AFS debt securities:
Amortized Cost	673,502	657,516
Gross Unrealized Gains		8,738
Gross Unrealized Losses		(16,589)
Fair Value		649,665
Corporate debt securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	673,502
Gross Unrealized Gains	0
Gross Unrealized Losses	(147,228)
Fair Value	526,274
Foreign government bonds
AFS debt securities:
Amortized Cost	241,165	260,447
Gross Unrealized Gains		767
Gross Unrealized Losses		(3,481)
Fair Value		257,733
Foreign government bonds | Debt securities available for sale
AFS debt securities:
Amortized Cost	241,165
Gross Unrealized Gains	174
Gross Unrealized Losses	(14,286)
Fair Value	227,053
Asset-backed securities
AFS debt securities:
Amortized Cost	51,152	74,674
Gross Unrealized Gains		185
Gross Unrealized Losses		(301)
Fair Value		74,558
Asset-backed securities | Debt securities available for sale
AFS debt securities:
Amortized Cost	51,152
Gross Unrealized Gains	0
Gross Unrealized Losses	(2,076)
Fair Value	49,076
CLOs
AFS debt securities:
Amortized Cost	617,250	592,250
Gross Unrealized Gains		52
Gross Unrealized Losses		(2,352)
Fair Value		$ 589,950
CLOs | Debt securities available for sale
AFS debt securities:
Amortized Cost	617,250
Gross Unrealized Gains	0
Gross Unrealized Losses	(19,586)
Fair Value	$ 597,664