Other Intangible Assets (Net Carrying Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other intangible assets:
Total other intangible assets	$ 34,271	$ 40,211
Core deposit intangible assets
Other intangible assets:
Total other intangible assets	34,259	40,211
Non-compete intangible assets
Other intangible assets:
Total other intangible assets	$ 12	$ 0