Investment Securities - Schedule of Available-for-sale Investment Securities Portfolios (Details) - USD ($)	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	$ 3,635,253,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(44,250,000)
Continuous unrealized losses existing for greater than 12 months, fair value	2,357,545,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(427,418,000)
Total, fair value	5,992,798,000
Total, unrealized losses	(471,668,000)
Available-for-sale securities, at fair value	7,244,282,000	$ 6,236,263,000	$ 4,220,305,000
U.S. government agencies
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	0
Continuous unrealized losses existing for less than 12 months, unrealized losses	0
Continuous unrealized losses existing for greater than 12 months, fair value	46,969,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(3,031,000)
Total, fair value	46,969,000
Total, unrealized losses	(3,031,000)
Available-for-sale securities, at fair value	46,969,000	47,471,000	45,944,000
Municipal
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	63,183,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(608,000)
Continuous unrealized losses existing for greater than 12 months, fair value	29,491,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(1,718,000)
Total, fair value	92,674,000
Total, unrealized losses	(2,326,000)
Available-for-sale securities, at fair value	174,259,000	162,166,000	188,149,000
Financial issuers
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	0
Continuous unrealized losses existing for less than 12 months, unrealized losses	0
Continuous unrealized losses existing for greater than 12 months, fair value	76,597,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(2,403,000)
Total, fair value	76,597,000
Total, unrealized losses	(2,403,000)
Available-for-sale securities, at fair value	76,597,000	76,296,000	80,435,000
Residential mortgage-backed securities
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	2,938,020,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(35,434,000)
Continuous unrealized losses existing for greater than 12 months, fair value	2,097,732,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(402,656,000)
Total, fair value	5,035,752,000
Total, unrealized losses	(438,090,000)
Available-for-sale securities, at fair value	5,991,658,000	5,156,683,000	3,586,000,000
Commercial (multi-family) mortgage-backed securities
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	232,695,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(5,441,000)
Continuous unrealized losses existing for greater than 12 months, fair value	44,959,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(2,611,000)
Total, fair value	277,654,000
Total, unrealized losses	(8,052,000)
Available-for-sale securities, at fair value	318,497,000	276,553,000	56,627,000
Collateralized mortgage obligations
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	401,355,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(2,767,000)
Continuous unrealized losses existing for greater than 12 months, fair value	61,797,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(14,999,000)
Total, fair value	463,152,000
Total, unrealized losses	(17,766,000)
Available-for-sale securities, at fair value	630,288,000	509,060,000	249,156,000
Mortgage-backed securities, subprime
Available-for-sale securities
Available-for-sale securities, at fair value	$ 0	$ 0	$ 0

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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