Acquisitions First Association Bank Acquisition - Narrative (Details) $ in Thousands	Mar. 15, 2013 USD ($) entity shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 50,832	$ 22,950	$ 17,428
First Association Bank
Business Acquisition [Line Items]
Consideration paid	$ 57,906
Cash consideration	$ 43,000
Number of shares of common stock issued as consideration | shares	1,279,217
Goodwill	$ 11,854	$ 11,900
Number of entities in business combination | entity	2