Investment Securities - Schedule of Available-for-sale Investment Securities Portfolios (Details) - USD ($)	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	$ 1,390,314,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(20,545,000)
Continuous unrealized losses existing for greater than 12 months, fair value	2,808,442,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(557,581,000)
Total, fair value	4,198,756,000
Total, unrealized losses	(578,126,000)
Available-for-sale securities, at fair value	4,329,957,000	$ 3,502,915,000	$ 3,492,481,000
U.S. Treasury
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	90,735,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(14,000)
Continuous unrealized losses existing for greater than 12 months, fair value	0
Continuous unrealized losses existing for greater than 12 months, unrealized losses	0
Total, fair value	90,735,000
Total, unrealized losses	(14,000)
Available-for-sale securities, at fair value	102,712,000	6,968,000	0
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	45,192,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(4,808,000)
Total, fair value	45,192,000
Total, unrealized losses	(4,808,000)
Available-for-sale securities, at fair value	45,192,000	45,124,000	74,275,000
Municipal
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	42,560,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(333,000)
Continuous unrealized losses existing for greater than 12 months, fair value	78,578,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(4,796,000)
Total, fair value	121,138,000
Total, unrealized losses	(5,129,000)
Available-for-sale securities, at fair value	146,608,000	140,958,000	167,411,000
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	76,985,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(7,011,000)
Total, fair value	76,985,000
Total, unrealized losses	(7,011,000)
Available-for-sale securities, at fair value	76,985,000	75,540,000	71,075,000
Other
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	990,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(10,000)
Total, fair value	990,000
Total, unrealized losses	(10,000)
Available-for-sale securities, at fair value	990,000	991,000	985,000
Residential mortgage-backed securities
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	1,226,130,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(19,491,000)
Continuous unrealized losses existing for greater than 12 months, fair value	2,537,424,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(522,251,000)
Total, fair value	3,763,554,000
Total, unrealized losses	(541,742,000)
Available-for-sale securities, at fair value	3,778,834,000	3,059,620,000	3,102,284,000
Commercial (multi-family) mortgage-backed securities
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	14,505,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(626,000)
Continuous unrealized losses existing for greater than 12 months, fair value	0
Continuous unrealized losses existing for greater than 12 months, unrealized losses	0
Total, fair value	14,505,000
Total, unrealized losses	(626,000)
Available-for-sale securities, at fair value	17,478,000	12,980,000
Collateralized mortgage obligations
Available-for-sale securities
Continuous unrealized losses existing for less than 12 months, fair value	16,384,000
Continuous unrealized losses existing for less than 12 months, unrealized losses	(81,000)
Continuous unrealized losses existing for greater than 12 months, fair value	69,273,000
Continuous unrealized losses existing for greater than 12 months, unrealized losses	(18,705,000)
Total, fair value	85,657,000
Total, unrealized losses	(18,786,000)
Available-for-sale securities, at fair value	161,158,000	160,734,000	76,451,000
Mortgage-backed securities, subprime
Available-for-sale securities
Available-for-sale securities, at fair value	$ 0	$ 0	$ 0