Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Cash and cash equivalents:
Cash and due from banks	$ 157,362	$ 185,708	$ 140,855
Interest-bearing deposits with banks	4,478	16,018	2,294
Federal funds sold and securities purchased under agreements to resell	274,641	179,004	166,770
Total cash and cash equivalents	436,481	380,730	309,919
Investment securities:
Securities held to maturity (fair value of $13,047, $16,553, and $17,743, respectively)	12,427	15,440	16,567
Securities available for sale, at fair value	511,347	534,883	478,472
Other investments	7,805	9,768	16,099
Total investment securities	531,579	560,091	511,138
Loans held for sale	47,980	65,279	42,525
Loans:
Loans, net	3,517,213	3,569,235	2,958,227
Premises and equipment, net	109,794	115,587	106,458
FDIC receivable for loss share agreements	104,048	146,171	200,569
Goodwill	100,193	100,193	66,542
Other real estate owned (covered of $35,142, $34,257, and $53,146, respectively; non-covered of $33,486, $32,803, and $31,263, respectively)	68,628	67,060	84,409
Bank owned life insurance	43,286	42,737	35,543
Core deposit and other intangibles	23,159	25,199	13,429
Other assets	60,717	64,131	44,510
Total assets	5,043,078	5,136,413	4,373,269
Deposits:
Noninterest-bearing	1,046,537	981,963	806,235
Interest-bearing	3,136,432	3,316,397	2,854,737
Total deposits	4,182,969	4,298,360	3,660,972
Federal funds purchased and securities sold under agreements to repurchase	262,447	238,621	220,264
Other borrowings	54,372	54,897	46,105
Other liabilities	26,698	36,986	21,022
Total liabilities	4,526,486	4,628,864	3,948,363
Shareholders' equity:
Preferred stock - $.01 par value; authorized 10,000,000 shares; no shares issued and outstanding
Common stock - $2.50 par value; authorized 40,000,000 shares; 17,032,061, 16,937,464, and 15,085,991 shares issued and outstanding	42,580	42,344	37,715
Surplus	330,563	328,843	262,647
Retained earnings	153,040	135,986	126,304
Accumulated other comprehensive income (loss)	(9,591)	376	(1,760)
Total shareholders' equity	516,592	507,549	424,906
Total liabilities and shareholders' equity	5,043,078	5,136,413	4,373,269
Acquired loans
Loans:
Loans, gross	921,840	1,074,742	560,058
Loans, allowance	(31,597)	(32,132)	(35,813)
Non-acquired loans
Loans:
Loans, gross	2,665,595	2,571,003	2,481,251
Loans, allowance	$ (38,625)	$ (44,378)	$ (47,269)