Mergers and Acquisitions - (Details 4) - Heritage Financial Group - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Business Acquisition [Line Items]
Interest income	$ 76,259	$ 75,905
Interest expense	6,205	6,861
Net interest income	70,054	69,044
Provision for loan and lease losses	1,800	1,150
Noninterest income	33,302	33,527
Noninterest expense	69,814	71,961
Income before income taxes	31,742	29,460
Income taxes	10,526	9,556
Net income	$ 21,216	$ 19,904
Earnings per share:
Basic (usd per share)	$ 0.53	$ 0.59
Diluted (usd per share)	$ 0.52	$ 0.59