Loans and Allowance for Loan Losses (Details 2) (Acquired loans, USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Loans and Allowance for Loan Losses
Total covered loans	$ 282,728	$ 394,495
Total non-covered loans	792,014	7,706
Total acquired loans	1,074,742	402,201
Less allowance for acquired loan losses	(32,132)	(31,620)
Loans, net	1,042,610	370,581	321,038
Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	110,414	167,334
Total non-covered loans	131,555	3,496
Total acquired loans	241,969
Less allowance for acquired loan losses	(24,988)	(23,875)
Loans, net	216,981	146,955
Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	172,314	227,161
Total non-covered loans	587,244	4,210
Total acquired loans	832,773
Less allowance for acquired loan losses	(7,144)	(7,745)
Loans, net	825,629	223,626
Commercial loans greater than or equal to $1 million-CBT
Loans and Allowance for Loan Losses
Total covered loans	49,684	60,829
Total acquired loans	49,684	60,829
Less allowance for acquired loan losses	(15,408)	(16,706)
Commercial loans greater than or equal to $1 million-CBT | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	19,483	24,073
Commercial loans greater than or equal to $1 million-CBT | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	30,201	36,756
Commercial real estate
Loans and Allowance for Loan Losses
Total covered loans	62,962	107,465
Total non-covered loans	309,962	862
Total acquired loans	372,924	108,327
Less allowance for acquired loan losses	(1,517)	(1,318)
Commercial real estate | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	22,946	39,685
Total non-covered loans	53,259	305
Commercial real estate | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	40,016	67,780
Total non-covered loans	256,703	557
Commercial real estate construction and development
Loans and Allowance for Loan Losses
Total covered loans	32,575	50,953
Total non-covered loans	97,876	52
Total acquired loans	130,451	51,005
Less allowance for acquired loan losses	(1,628)
Commercial real estate construction and development | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	15,107	29,528
Total non-covered loans	32,975	5
Commercial real estate construction and development | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	17,468	21,425
Total non-covered loans	64,901	47
Residential real estate
Loans and Allowance for Loan Losses
Total covered loans	104,811	127,658
Total non-covered loans	250,316	997
Total acquired loans	355,127	128,650
Less allowance for acquired loan losses	(4,616)	(5,471)
Residential real estate | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	39,050	52,727
Total non-covered loans	40,585	244
Residential real estate | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	65,761	74,926
Total non-covered loans	209,731	753
Consumer
Loans and Allowance for Loan Losses
Total covered loans	4,324	7,033
Total non-covered loans	11,361	2,986
Total acquired loans	15,685	10,019
Less allowance for acquired loan losses	(96)
Consumer | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	948	2,669
Total non-covered loans	1,672	2,723
Consumer | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	3,376	4,364
Total non-covered loans	9,689	263
Commercial and industrial
Loans and Allowance for Loan Losses
Total covered loans	23,600	36,502
Total non-covered loans	49,284	2,809
Total acquired loans	72,884	39,311
Less allowance for acquired loan losses	(4,305)	(4,564)
Commercial and industrial | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	8,281	14,800
Total non-covered loans	3,064	219
Commercial and industrial | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	15,319	21,702
Total non-covered loans	46,220	2,590
Single pay
Loans and Allowance for Loan Losses
Total covered loans	4,772	4,060
Total acquired loans	4,772	4,060
Less allowance for acquired loan losses	(4,562)	(3,561)
Single pay | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	4,599	3,852
Single pay | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	173	208
Total FASB ASC Topic 310-30 acquired loans
Loans and Allowance for Loan Losses
Total covered loans	282,728	394,495
Total non-covered loans	718,799	7,706
Total acquired loans	1,001,527	402,201
Loans, net	969,395	370,581	321,038
Total FASB ASC Topic 310-30 acquired loans | Loans Impaired at Acquisition
Loans and Allowance for Loan Losses
Total covered loans	282,728	394,495
Total non-covered loans	718,799	7,706
Total acquired loans	241,969	170,830
Less allowance for acquired loan losses	(24,988)	(23,875)
Loans, net	216,981	146,955	143,059
Total FASB ASC Topic 310-30 acquired loans | Loans Not Impaired at Acquisition
Loans and Allowance for Loan Losses
Total acquired loans	759,558	231,371
Less allowance for acquired loan losses	(7,144)	(7,745)
Loans, net	825,629	223,626	177,979
Total FASB ASC Topic 310-20 acquired loans (non-covered)
Loans and Allowance for Loan Losses
Total non-covered loans	73,215
Loans, net	73,215
Home equity
Loans and Allowance for Loan Losses
Total acquired loans		$ 1,386