Acquisitions and Divestitures - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Combinations [Abstract]
Total revenue (net interest income plus other income)	$ 291,614	$ 284,890	$ 253,668
Net income	60,497	64,174	39,979
Net income available to common shareholders	$ 60,497	$ 64,174	$ 37,559
Earnings per share:
Basic (in dollars per share)	$ 1.49	$ 1.58	$ 0.98
Diluted (in dollars per share)	$ 1.48	$ 1.57	$ 0.97