Goodwill and Other Intangible Assets - Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2023
Goodwill [Roll Forward]
Beginning balance		$ 1,459,008
Ending balance		1,868,936
Goodwill		1,868,936	$ 1,868,936
Revision of Prior Period, Adjustment
Goodwill [Roll Forward]
Beginning balance		0
Goodwill from business combinations, as adjusted		409,928
Ending balance		0
Goodwill		0
Previously Reported
Goodwill [Roll Forward]
Beginning balance		1,459,008
Ending balance		1,868,936
Goodwill		1,868,936
Consumer Banking
Goodwill [Roll Forward]
Beginning balance		349,557
Goodwill from business combinations, as adjusted	$ 41,300
Ending balance		349,646
Goodwill		349,646	349,646
Consumer Banking | Revision of Prior Period, Adjustment
Goodwill [Roll Forward]
Beginning balance		127,167
Goodwill from business combinations, as adjusted	(62,400)	89
Ending balance		64,773
Goodwill		64,773
Consumer Banking | Previously Reported
Goodwill [Roll Forward]
Beginning balance		222,390
Ending balance		284,873
Goodwill		284,873
Commercial Banking
Goodwill [Roll Forward]
Beginning balance		1,075,136
Ending balance		1,441,148
Goodwill		1,441,148	1,441,148
Commercial Banking | Revision of Prior Period, Adjustment
Goodwill [Roll Forward]
Beginning balance		(122,631)
Goodwill from business combinations, as adjusted	29,400	366,012
Ending balance		(93,148)
Goodwill		(93,148)
Commercial Banking | Previously Reported
Goodwill [Roll Forward]
Beginning balance		1,197,767
Ending balance		1,534,296
Goodwill		1,534,296
Wealth Management | Consumer Banking
Goodwill [Roll Forward]
Beginning balance		34,315
Ending balance		78,142
Goodwill		78,142	$ 78,142
Wealth Management | Consumer Banking | Revision of Prior Period, Adjustment
Goodwill [Roll Forward]
Beginning balance		(4,536)
Goodwill from business combinations, as adjusted	$ 32,900	43,827
Ending balance		28,375
Goodwill		28,375
Wealth Management | Consumer Banking | Previously Reported
Goodwill [Roll Forward]
Beginning balance		38,851
Ending balance		49,767
Goodwill		$ 49,767