Investment Securities - Schedule of Contractual Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024
Available-for-sale securities
Due in one year or less, amortized cost	$ 61,653	$ 89,578	$ 107,680
Due in one to five years, amortized cost	160,377	157,883	130,137
Due in five to ten years, amortized cost	89,444	89,125	85,212
Due after ten years, amortized cost	27,136	24,674	17,904
Amortized Cost	4,729,234	4,725,539	4,942,360
Due in one year or less, fair value	61,702	89,392	107,285
Due in one to five years, fair value	156,869	153,325	121,417
Due in five to ten years, fair value	85,935	84,240	80,234
Due after ten years, fair value	24,016	21,650	15,269
Fair Value	4,220,305	4,141,482	4,387,598
Held-to-maturity securities
Held-to-maturity securities, due in one year or less, amortized cost	27,766	18,929	4,652
Held-to-maturity securities, due in one to five years, amortized cost	103,583	110,897	115,707
Held-to-maturity securities, due in five to ten years, amortized cost	94,324	71,846	89,538
Held-to-maturity securities, due after ten years, amortized cost	302,854	329,734	352,428
Amortized Cost	3,564,936	3,613,720	3,810,344
Less: Allowance for credit losses	(446)	(457)	(329)
Held-to-maturity securities, net of allowance for credit losses	3,564,490	3,613,263	3,810,015
Held-to-maturity securities, due in one year or less, fair value	27,436	18,658	4,616
Held-to-maturity securities, due in one to five years, fair value	101,546	108,056	111,324
Held-to-maturity securities, due in five to ten years, fair value	88,875	70,277	88,050
Held-to-maturity securities, due after ten years, fair value	242,029	258,379	280,536
Fair Value	2,922,813	2,910,550	3,111,954
Mortgage-backed
Available-for-sale securities
Mortgage-backed, without single maturity date, amortized cost	4,390,624	4,364,279	4,601,427
Mortgage-backed, without single maturity date, fair value	3,891,783	3,792,875	4,063,393
Held-to-maturity securities
Mortgage-backed, amortized cost	3,036,409	3,082,314	3,248,019
Mortgage-backed, fair value	$ 2,462,927	$ 2,455,180	$ 2,627,428