Investment Securities - Schedule of Unrealized Loss on Available-for-Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair value
Less than 12 months	$ 2,084,238	$ 419,704
12 months or more	1,411,003	1,479,874
Total	3,495,241	1,899,578
Unrealized losses
Less than 12 months	(15,229)	(1,190)
12 months or more	(106,411)	(103,392)
Total	(121,640)	(104,582)
U.S. government obligations and government- sponsored enterprises
Fair value
Less than 12 months	2,083,763	419,704
12 months or more	1,401,353	1,469,113
Total	3,485,116	1,888,817
Unrealized losses
Less than 12 months	(15,229)	(1,190)
12 months or more	(106,293)	(103,318)
Total	(121,522)	(104,508)
Obligations of states and political subdivisions
Fair value
Less than 12 months	475	0
12 months or more	6,229	7,204
Total	6,704	7,204
Unrealized losses
Less than 12 months	0	0
12 months or more	(52)	(38)
Total	(52)	(38)
Other securities
Fair value
Less than 12 months	0	0
12 months or more	3,421	3,557
Total	3,421	3,557
Unrealized losses
Less than 12 months	0	0
12 months or more	(66)	(36)
Total	$ (66)	$ (36)