Goodwill and Other Intangible Assets Goodwill and Other Intangible Assets - Schedule of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 690,637
Goodwill from business combinations	388,255
Goodwill, ending balance	1,078,892
Wealth Management
Goodwill [Roll Forward]
Goodwill, beginning balance	21,218
Goodwill from business combinations	0
Goodwill, ending balance	21,218
Consumer Lending
Goodwill [Roll Forward]
Goodwill, beginning balance	200,103
Goodwill from business combinations	85,649
Goodwill, ending balance	285,752
Commercial Lending
Goodwill [Roll Forward]
Goodwill, beginning balance	316,258
Goodwill from business combinations	238,052
Goodwill, ending balance	554,310
Investment Management
Goodwill [Roll Forward]
Goodwill, beginning balance	153,058
Goodwill from business combinations	64,554
Goodwill, ending balance	$ 217,612