Mergers and Acquisitions (Details Textual) $ in Thousands	Apr. 01, 2016 USD ($) branch shares	Jul. 01, 2015 USD ($) branch shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 470,534	$ 445,871	$ 274,706
Intangible acquired			$ 24,074	$ 28,811
KeyWorth Bank
Business Acquisition [Line Items]
Transaction value	$ 58,884
Consideration paid to stock option and warrant holders	$ 3,594
Percentage of voting interests acquired (percent)	100.00%
Total net assets acquired	$ 415,232
Borrowings	$ 272,330
Number of offices in operation | branch	6
Intangible assets	$ 22,643
Goodwill	20,633
Intangible acquired	$ 2,010
Useful life (in years)	10 years
KeyWorth Bank | Core deposit intangible
Business Acquisition [Line Items]
Deposits assumed	$ 348,961
KeyWorth Bank | Common Stock
Business Acquisition [Line Items]
Shares issued to common shareholders (shares) | shares	1,680,021
Heritage Financial Group
Business Acquisition [Line Items]
Transaction value		$ 295,444
Consideration paid to stock option and warrant holders		$ 5,915
Percentage of voting interests acquired (percent)		100.00%
Total net assets acquired		$ 120,232
Borrowings		$ 314,656
Number of banking, mortgage, and investment offices (branches) | branch		48
Intangible assets		$ 187,468
Goodwill		175,212
Intangible acquired		$ 12,256
Heritage Financial Group | Core deposit intangible
Business Acquisition [Line Items]
Useful life (in years)		10 years
Heritage Financial Group | Common Stock
Business Acquisition [Line Items]
Shares issued to common shareholders (shares) | shares		8,635,879