Parent Company Financial Information - Statements of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income
Net loss on debt extinguishment	$ 793	$ 0	$ (180)
Expense
Interest expense	18,244	18,242	22,449
Compensation and benefits	213,692	225,245	215,690
Other noninterest expense	406,951	396,670	380,277
Net income before income taxes	34,041	384,358	460,823
Income tax benefit	3,189	100,615	120,934
Net Income (Loss) Available to Common Stockholders, Basic, Total	28,791	280,338	336,372
Corporation
Income
Dividend income from the Bank	199,653	131,160	121,653
Interest income	93	7	9
Net loss on debt extinguishment	0	0	(2,877)
Total income	199,746	131,167	118,785
Expense
Interest expense	18,244	18,242	18,907
Compensation and benefits	3,934	5,198	3,845
Other noninterest expense	3,785	3,881	3,808
Total expense	25,963	27,321	26,560
Net income before income taxes	173,783	103,846	92,225
Income tax benefit	(7,240)	(7,793)	(8,672)
Income before undistributed income of subsidiary	181,023	111,639	100,897
Equity in undistributed (losses) earnings of subsidiary	(150,171)	172,104	238,992
Net Income (Loss) Available to Common Stockholders, Basic, Total	$ 30,852	$ 283,743	$ 339,889