Securities Available for Sale and Held to Maturity - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Reclassification of Securities available for sale to securities held to maturity					$ 766,000,000
Net unrealized holding loss on AFS Securities at date of transfer					91,900,000
Net unrealized holding losses on AFS Securities, net of tax at date of transfer					$ (68,900,000)
Net unamortized, unrealized loss on transfer of securities	$ 44,100,000	$ 46,600,000
Credit loss recognized	0	0
Expected credit losses, current.	0	0
Reserve for securities held to maturity	0	0	$ 0	$ 0
Securities held to maturity	1,315,053,000	1,335,385,000
Pledged to collateralize public deposits and securities sold under repurchase agreements and for other purposes as permitted by law	1,887,000,000	1,910,000,000
Pledged securities providing additional contingency funding	0	0
Past Due 30 to 59 Days [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Securities held to maturity	0	0
Securities Available for Sale [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Accrued interest receivable	5,600,000	5,000,000
Securities Held to Maturity [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Accrued interest receivable	2,500,000	2,400,000
Held-to-maturity nonnaccrual	$ 0	$ 0