Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Cash and cash equivalents:
Cash and due from banks	$ 266,387	$ 185,708	$ 105,851
Interest-bearing deposits with banks	30,963	16,018	2,341
Federal funds sold and securities purchased under agreements to resell	347,821	179,004	169,872
Total cash and cash equivalents	645,171	380,730	278,064
Investment securities:
Securities held to maturity (fair value of $12,992, $16,553, and $17,750, respectively)	12,426	15,440	16,568
Securities available for sale, at fair value	626,798	534,883	476,023
Other investments	13,386	9,768	7,996
Total investment securities	652,610	560,091	500,587
Loans held for sale	52,467	65,279	71,585
Loans:
Loans, net	5,687,059	3,569,235	2,960,766
Goodwill	319,180	101,286	66,895
Premises and equipment, net	184,959	115,583	105,579
FDIC receivable for loss share agreements	115,773	146,171	174,321
Bank owned life insurance	96,551	42,737	35,785
Other real estate owned (covered of $40,543, $34,257 and $47,063, respectively; non-covered of $35,330, $32,248 and $27,484, respectively)	75,873	66,505	74,547
Core deposit and other intangibles	62,195	25,199	12,862
Other assets	136,603	63,597	44,241
Total assets	8,028,441	5,136,413	4,325,232
Deposits:
Noninterest-bearing	1,481,791	981,963	818,633
Interest-bearing	5,181,315	3,316,397	2,770,665
Total deposits	6,663,106	4,298,360	3,589,298
Federal funds purchased and securities sold under agreements to repurchase	233,792	238,621	226,330
Other borrowings	101,347	54,897	45,807
Other liabilities	60,170	36,986	29,873
Total liabilities	7,058,415	4,628,864	3,891,308
Shareholders' equity:
Preferred stock - $.01 par value; authorized 10,000,000 shares; 65,000, 0, and 0 shares issued and outstanding , respectively	1
Common stock - $2.50 par value; authorized 40,000,000 shares; 24,066,545, 16,937,464 and 15,114,185 shares issued and outstanding, respectively	60,166	42,344	37,785
Surplus	760,507	328,843	263,569
Retained earnings	159,980	135,986	132,798
Accumulated other comprehensive income (loss)	(10,628)	376	(228)
Total shareholders' equity	970,026	507,549	433,924
Total liabilities and shareholders' equity	8,028,441	5,136,413	4,325,232
Acquired loans
Loans:
Loans, gross	3,013,103	1,074,742	520,991
Loans, allowance	(31,141)	(32,132)	(31,138)
Non-acquired loans
Loans:
Loans, gross	2,741,242	2,571,003	2,517,352
Loans, allowance	$ (36,145)	$ (44,378)	$ (46,439)