Intangible Assets (Net Carrying Value) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Net carrying value of intangible assets
Goodwill	$ 120,164		$ 120,164	$ 120,164
Other intangible assets:
Total other intangible assets	11,958		13,424	13,865
Core deposit intangible assets [Member]
Other intangible assets:
Total other intangible assets	8,665		10,001	10,466
Mortgage servicing rights [Member]
Other intangible assets:
Total other intangible assets	$ 3,293	$ 3,344	$ 3,423	$ 3,399	$ 3,421	$ 3,478