Securities - Schedule of Debt Securities (Details) - USD ($)	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 4,155,341,000	$ 4,778,644,000
Unrealized Gains	25,428,000	0
Unrealized Losses	(370,138,000)	(757,046,000)
Allowance for Credit Losses	0	0	$ 0
Fair Value	3,810,631,000	4,021,598,000
Government-sponsored residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,756,870,000	3,099,328,000
Unrealized Gains	16,384,000	0
Unrealized Losses	(254,951,000)	(537,433,000)
Allowance for Credit Losses	0	0
Fair Value	2,518,303,000	2,561,895,000
Government-sponsored commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,156,696,000	1,362,519,000
Unrealized Gains	8,737,000	0
Unrealized Losses	(102,382,000)	(201,408,000)
Allowance for Credit Losses	0	0
Fair Value	1,063,051,000	1,161,111,000
U.S. Agency bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		19,608,000
Unrealized Gains		0
Unrealized Losses		(1,936,000)
Allowance for Credit Losses		0
Fair Value		17,672,000
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	50,034,000	99,784,000
Unrealized Gains	292,000	0
Unrealized Losses	0	(2,165,000)
Allowance for Credit Losses	0	0
Fair Value	50,326,000	97,619,000
State and municipal bonds and obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	191,741,000	197,405,000
Unrealized Gains	15,000	0
Unrealized Losses	(12,805,000)	(14,104,000)
Allowance for Credit Losses	0	0
Fair Value	$ 178,951,000	$ 183,301,000