Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investment securities:
Securities held to maturity, fair value (in dollars)	$ 12,891	$ 16,553
Other real estate owned
Other real estate owned, covered (in dollars)	27,520	34,257	65,849
Other real estate owned, non-covered (in dollars)	37,398	32,248	18,022
Shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	65,000	0
Preferred stock, shares outstanding	65,000	0
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	24,104,124	16,937,464
Common stock, shares outstanding	24,104,124	16,937,464
Acquired loans
Loans:
Non-covered loans			7,706
Total FASB ASC Topic 310-20 acquired loans (non-covered) | Acquired loans
Loans:
Covered loans	7,824	0
Non-covered	1,590,227	73,215
Credit impaired | Acquired loans
Loans:
Covered loans	289,122	250,596
Non-covered	$ 926,958	$ 718,799