Securities - Gross Unrealized Losses and Fair Value of Company's Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	$ 880,068	$ 1,500,686
Unrealized losses less than 12 months	(75,452)	(21,993)
Fair value more than 12 months	1,719,396	35,281
Unrealized losses more than 12 months	(406,840)	(1,012)
Total fair value	2,599,464	1,535,967
Total unrealized losses	(482,292)	(23,005)
U.S. Treasury and federal agencies
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	217,357	268,732
Unrealized losses less than 12 months	(16,692)	(2,483)
Fair value more than 12 months	295,585	15,820
Unrealized losses more than 12 months	(59,695)	(430)
Total fair value	512,942	284,552
Total unrealized losses	(76,387)	(2,913)
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	533,871	539,882
Unrealized losses less than 12 months	(45,881)	(9,389)
Fair value more than 12 months	757,061	19,461
Unrealized losses more than 12 months	(218,179)	(582)
Total fair value	1,290,932	559,343
Total unrealized losses	(264,060)	(9,971)
Federal agency collateralized mortgage obligations
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	40,301	56,027
Unrealized losses less than 12 months	(2,881)	(1,032)
Fair value more than 12 months	38,613	0
Unrealized losses more than 12 months	(7,780)	0
Total fair value	78,914	56,027
Total unrealized losses	(10,661)	(1,032)
Federal agency mortgage–backed pools
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	49,633	406,540
Unrealized losses less than 12 months	(3,211)	(5,418)
Fair value more than 12 months	428,243	0
Unrealized losses more than 12 months	(83,810)	0
Total fair value	477,876	406,540
Total unrealized losses	(87,021)	(5,418)
Private labeled mortgage–backed pools
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	0	40,005
Unrealized losses less than 12 months	0	(442)
Fair value more than 12 months	29,973	0
Unrealized losses more than 12 months	(5,493)	0
Total fair value	29,973	40,005
Total unrealized losses	(5,493)	(442)
Corporate notes
Schedule of Available-for-sale Securities [Line Items]
Fair Value less than 12 months	38,906	189,500
Unrealized losses less than 12 months	(6,787)	(3,229)
Fair value more than 12 months	169,921	0
Unrealized losses more than 12 months	(31,883)	0
Total fair value	208,827	189,500
Total unrealized losses	$ (38,670)	$ (3,229)