Goodwill and Identifiable Intangible Assets - Goodwill by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 385,270	$ 379,627
Additions		5,643
Adjustment	(1,033)
Balance, end of period	384,237	385,270
General Banking [Member]
Goodwill [Roll Forward]
Goodwill, beginning of period	334,603	334,603
Balance, end of period	334,603	334,603
Insurance [Member]
Goodwill [Roll Forward]
Goodwill, beginning of period	50,667	45,024
Additions		5,643
Adjustment	(1,033)
Balance, end of period	$ 49,634	$ 50,667