Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Income Statement Data Abstract
Net interest income	$ 274,010	$ 187,747
Net intersegment interest income (expense)	0	0
Segment net interest income	274,010	187,747
Noninterest income	62,073	74,467
Total revenue	336,083	262,214
Provision for credit losses	17,971	(3,990)
Noninterest expense	187,412	173,292
Income before income taxes	130,700	92,912
Income tax expense (benefit)	27,340	18,650
Net income	103,360	74,262
Goodwill	1,104,992	1,104,992	$ 1,104,992
Operating Segments | Corporate and Commercial Specialty
Segment Income Statement Data Abstract
Net interest income	219,123	90,633
Net intersegment interest income (expense)	(80,980)	8,525
Segment net interest income	138,143	99,158
Noninterest income	32,715	37,728
Total revenue	170,858	136,886
Provision for credit losses	13,782	12,653
Noninterest expense	62,061	56,528
Income before income taxes	95,015	67,705
Income tax expense (benefit)	17,737	12,307
Net income	77,278	55,399
Goodwill	525,836	525,836
Operating Segments | Community, Consumer, and Business
Segment Income Statement Data Abstract
Net interest income	80,284	69,544
Net intersegment interest income (expense)	88,079	18,833
Segment net interest income	168,363	88,377
Noninterest income	25,949	33,207
Total revenue	194,312	121,584
Provision for credit losses	6,758	4,656
Noninterest expense	111,694	98,461
Income before income taxes	75,860	18,466
Income tax expense (benefit)	15,931	3,878
Net income	59,930	14,588
Goodwill	579,156	579,156
Operating Segments | Risk Management and Shared Services
Segment Income Statement Data Abstract
Net interest income	(25,397)	27,570
Net intersegment interest income (expense)	(7,099)	(27,358)
Segment net interest income	(32,496)	212
Noninterest income	3,409	3,532
Total revenue	(29,087)	3,744
Provision for credit losses	(2,568)	(21,300)
Noninterest expense	13,658	18,303
Income before income taxes	(40,176)	6,741
Income tax expense (benefit)	(6,328)	2,465
Net income	(33,848)	4,275
Goodwill	$ 0	$ 0