Investment Securities - Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Debt Securities Available for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,391,554	$ 1,454,439
Gross Unrealized Gains	1,647	747
Gross Unrealized Losses	(181,109)	(158,610)
Fair Value	2,212,092	1,296,576
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	316,642	313,772
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(30,368)	(25,615)
Fair Value	286,274	288,157
U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	25,177	25,967
Gross Unrealized Gains	23	19
Gross Unrealized Losses	(2,434)	(2,284)
Fair Value	22,766	23,702
Obligations of states and state agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	50,154	48,283
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(676)	(588)
Fair Value	49,478	47,695
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	171,552	170,260
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(32,342)	(26,265)
Fair Value	139,210	143,995
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	221,706	218,543
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(33,018)	(26,853)
Fair Value	188,688	191,690
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,625,542	703,875
Gross Unrealized Gains	1,565	728
Gross Unrealized Losses	(91,417)	(78,031)
Fair Value	1,535,690	626,572
Corporate and other debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	202,487	192,282
Gross Unrealized Gains	59	0
Gross Unrealized Losses	(23,872)	(25,827)
Fair Value	$ 178,674	$ 166,455