Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investment securities:
Securities held to maturity, fair value (in dollars)	$ 16,553	$ 17,864
Other real estate owned
Other real estate owned, covered (in dollars)	34,257	65,849
Other real estate owned, non-covered (in dollars)	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
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	16,937,464	14,039,422
Common stock, shares outstanding	16,937,464	14,039,422
Acquired loans
Loans:
Covered loans	282,728	394,495
Non-covered loans	$ 792,014	$ 7,706