Securities - Schedule of Debt Securities (Details) - USD ($)	Dec. 31, 2025	Dec. 31, 2024
AFS debt securities:
Amortized Cost	$ 13,619,781,000	$ 11,505,775,000
Gross Unrealized Gains	69,974,000	15,273,000
Gross Unrealized Losses	(475,635,000)	(674,237,000)
Allowance for Credit Losses	(1,900,000)	0
Fair Value	13,212,220,000	10,846,811,000
HTM debt securities
Amortized Cost	2,870,058,000	2,917,413,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(390,312,000)	(529,659,000)
Allowance for Credit Losses	0	0
Fair Value	2,479,746,000	2,387,754,000
Total debt securities
Amortized Cost	16,489,839,000	14,423,188,000
Gross Unrealized Gains	69,974,000	15,273,000
Gross Unrealized Losses	(865,947,000)	(1,203,896,000)
Allowance for Credit Losses	(1,900,000)
Fair Value	15,691,966,000	13,234,565,000
AFS and HTM, accrued interest	54,000,000	45,000,000
Government National Mortgage Association (GNMA)
AFS debt securities:
Amortized Cost	9,600,000,000	7,300,000,000
Fair Value	9,600,000,000	7,200,000,000
HTM debt securities
Amortized Cost	79,000,000	86,000,000
Fair Value	65,000,000	68,000,000
U.S. Treasury securities
AFS debt securities:
Amortized Cost	1,010,053,000	676,300,000
Gross Unrealized Gains	837,000	0
Gross Unrealized Losses	(16,977,000)	(38,035,000)
Allowance for Credit Losses	0
Fair Value	993,913,000	638,265,000
HTM debt securities
Amortized Cost	540,666,000	535,080,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(15,779,000)	(35,222,000)
Allowance for Credit Losses	0
Fair Value	524,887,000	499,858,000
U.S. government agency and U.S. government-sponsored enterprise debt securities
AFS debt securities:
Amortized Cost	287,687,000	308,220,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(30,033,000)	(45,633,000)
Allowance for Credit Losses	0
Fair Value	257,654,000	262,587,000
HTM debt securities
Amortized Cost	1,007,055,000	1,004,479,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(146,921,000)	(200,259,000)
Allowance for Credit Losses	0
Fair Value	860,134,000	804,220,000
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
AFS debt securities:
Amortized Cost	292,564,000	472,535,000
Gross Unrealized Gains	86,000	886,000
Gross Unrealized Losses	(27,312,000)	(47,207,000)
Allowance for Credit Losses	0
Fair Value	265,338,000	426,214,000
HTM debt securities
Amortized Cost	474,747,000	486,388,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(69,471,000)	(91,461,000)
Allowance for Credit Losses	0
Fair Value	405,276,000	394,927,000
US government agencies And U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
AFS debt securities:
Amortized Cost	10,251,714,000	7,974,768,000
Gross Unrealized Gains	68,588,000	12,278,000
Gross Unrealized Losses	(187,649,000)	(248,786,000)
Allowance for Credit Losses	0
Fair Value	10,132,653,000	7,738,260,000
HTM debt securities
Amortized Cost	662,127,000	703,833,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(124,176,000)	(155,626,000)
Allowance for Credit Losses	0
Fair Value	537,951,000	548,207,000
Municipal securities
AFS debt securities:
Amortized Cost	277,275,000	287,301,000
Gross Unrealized Gains	20,000	38,000
Gross Unrealized Losses	(34,193,000)	(37,186,000)
Allowance for Credit Losses	0
Fair Value	243,102,000	250,153,000
HTM debt securities
Amortized Cost	185,463,000	187,633,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(33,965,000)	(47,091,000)
Allowance for Credit Losses	0
Fair Value	151,498,000	140,542,000
Non-agency commercial mortgage-backed Securities
AFS debt securities:
Amortized Cost	214,987,000	294,235,000
Gross Unrealized Gains	0	2,000
Gross Unrealized Losses	(22,139,000)	(35,767,000)
Allowance for Credit Losses	(1,900,000)
Fair Value	190,948,000	258,470,000
Non-agency residential mortgage-backed Securities
AFS debt securities:
Amortized Cost	452,208,000	514,527,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(58,421,000)	(80,919,000)
Allowance for Credit Losses	0
Fair Value	393,787,000	433,608,000
Corporate debt securities
AFS debt securities:
Amortized Cost	554,158,000	653,500,000
Gross Unrealized Gains	6,000	0
Gross Unrealized Losses	(89,183,000)	(127,334,000)
Allowance for Credit Losses	0
Fair Value	464,981,000	526,166,000
Foreign government bonds
AFS debt securities:
Amortized Cost	247,249,000	244,803,000
Gross Unrealized Gains	437,000	2,069,000
Gross Unrealized Losses	(9,231,000)	(12,992,000)
Allowance for Credit Losses	0
Fair Value	238,455,000	233,880,000
Asset-backed securities
AFS debt securities:
Amortized Cost	31,886,000	35,086,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(497,000)	(371,000)
Allowance for Credit Losses	0
Fair Value	$ 31,389,000	34,715,000
Collateralized loan obligations (“CLOs”)
AFS debt securities:
Amortized Cost		44,500,000
Gross Unrealized Gains		0
Gross Unrealized Losses		(7,000)
Fair Value		$ 44,493,000