Goodwill and Other Intangible Assets (Summary of Finite-Lived Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Indefinite-lived Intangible Assets by Major Class [Line Items]
Total other intangible assets, net	$ 17,621	$ 21,851
Community banking | Core deposit intangibles:
Indefinite-lived Intangible Assets by Major Class [Line Items]
Gross carrying amount	37,272	37,272
Accumulated amortization	(25,427)	(21,614)
Net carrying amount	11,845	15,658
Specialty finance | Customer list intangibles:
Indefinite-lived Intangible Assets by Major Class [Line Items]
Gross carrying amount	1,972	1,800
Accumulated amortization	(1,298)	(1,159)
Net carrying amount	674	641
Wealth management | Customer list and other intangibles:
Indefinite-lived Intangible Assets by Major Class [Line Items]
Gross carrying amount	7,940	7,940
Accumulated amortization	(2,838)	(2,388)
Net carrying amount	$ 5,102	$ 5,552