Investment Securities - Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Debt Securities Held to Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 3,545,961	$ 3,532,220
Gross Unrealized Gains	5,057	2,107
Gross Unrealized Losses	(453,384)	(506,043)
Fair Value	3,097,634	3,028,284
Allowance for Credit Losses	633	647	$ 1,131	$ 647	$ 1,205
Net Carrying Value	3,545,328	3,531,573
U.S. Treasury securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	25,290	25,480
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(21)	(19)
Fair Value	25,269	25,461
Allowance for Credit Losses	0	0
Net Carrying Value	25,290	25,480
U.S. government agency securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	300,865	301,315
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(40,993)	(49,013)
Fair Value	259,872	252,302
Allowance for Credit Losses	0	0
Net Carrying Value	300,865	301,315
Obligations of states and state agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	66,602	68,025
Gross Unrealized Gains	53	0
Gross Unrealized Losses	(4,799)	(5,335)
Fair Value	61,856	62,690
Allowance for Credit Losses	1	2
Net Carrying Value	66,601	68,023
Municipal bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	291,584	304,464
Gross Unrealized Gains	11	9
Gross Unrealized Losses	(24,330)	(20,802)
Fair Value	267,265	283,671
Allowance for Credit Losses	46	48
Net Carrying Value	291,538	304,416
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	358,186	372,489
Gross Unrealized Gains	64	9
Gross Unrealized Losses	(29,129)	(26,137)
Fair Value	329,121	346,361
Allowance for Credit Losses	47	50
Net Carrying Value	358,139	372,439
Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	2,742,355	2,710,642
Gross Unrealized Gains	4,985	2,088
Gross Unrealized Losses	(374,064)	(420,582)
Fair Value	2,373,276	2,292,148
Allowance for Credit Losses	0	0
Net Carrying Value	2,742,355	2,710,642
Trust preferred securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	36,086	36,081
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6,606)	(6,936)
Fair Value	29,480	29,145
Allowance for Credit Losses	418	414
Net Carrying Value	35,668	35,667
Corporate and other debt securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	83,179	86,213
Gross Unrealized Gains	8	10
Gross Unrealized Losses	(2,571)	(3,356)
Fair Value	80,616	82,867
Allowance for Credit Losses	168	183
Net Carrying Value	$ 83,011	$ 86,030