Goodwill and Other Intangible Assets (Goodwill Assets by Business Segment) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 501,884
Goodwill Acquired	73,164
Impairment Loss	0
Goodwill Adjustments	(1,907)
Ending balance	573,141
Community banking
Goodwill [Roll Forward]
Beginning balance	429,520
Goodwill Acquired	35,565
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	465,085
Specialty finance
Goodwill [Roll Forward]
Beginning balance	40,250
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	(1,907)
Ending balance	38,343
Wealth management
Goodwill [Roll Forward]
Beginning balance	32,114
Goodwill Acquired	37,599
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	$ 69,713