Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Investment securities:
Securities held to maturity, fair value (in dollars)	$ 17,743	$ 17,864	$ 19,834
Other real estate owned
Other real estate owned, covered (in dollars)	53,146	65,849	74,591
Other real estate owned, non-covered (in dollars)	31,263	18,022	24,900
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	15,085,991	14,039,422	13,987,686
Common stock, shares outstanding	15,085,991	14,039,422	13,987,686
Acquired loans
Loans:
Total covered loans	332,874	394,495	369,658
Non-covered loans	$ 227,184	$ 7,706	$ 9,683