Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Preferred stock, shares issued	0	0	0
Preferred stock, shares outstanding	0	0	0
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50	$ 2.50
Common stock, shares authorized	40,000,000	40,000,000	40,000,000
Common stock, shares issued	29,259,264	24,230,392	24,195,226
Common stock, shares outstanding	24,259,264	24,230,392	24,195,226
Investment securities:
Securities held to maturity, fair value (in dollars)	$ 4,248	$ 6,250	$ 8,231
Loans:
Non-covered	8,140,706	6,643,326	6,380,657
Other real estate owned
Other real estate owned, non-covered (in dollars)	$ 14,430	$ 18,316	$ 22,427