Loans and Allowance for Loan Losses (Details 7) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Allowance for loan losses:
Provision for loan losses before benefit attributable to FDIC loss share agreements	$ (2)	$ 5,033
Benefit attributable to FDIC loss share agreements	1,062	(2,310)
Total provision for loan losses charged to operations	1,060	2,723
Provision for loan losses recorded through the FDIC loss share receivable	(1,062)	2,310
Acquired loans
Allowance for loan losses:
Balance at the beginning of the period	32,132	31,620
Provision for loan losses before benefit attributable to FDIC loss share agreements	(855)	2,735
Benefit attributable to FDIC loss share agreements	1,062	(2,310)
Total provision for loan losses charged to operations	207	425
Provision for loan losses recorded through the FDIC loss share receivable	(1,062)	2,310
Balance at the end of the period	31,277	34,355
Loans collectively evaluated for impairment	32,132	34,355
Loans:
Loans collectively evaluated for impairment	995,255	369,144
Total acquired loans	995,255	369,144	1,074,742
Acquired loans | Commercial Loans Greater Than or Equal to $1 Million-CBT
Allowance for loan losses:
Balance at the beginning of the period	15,408	16,706
Provision for loan losses before benefit attributable to FDIC loss share agreements	(452)	145
Benefit attributable to FDIC loss share agreements	429	(138)
Total provision for loan losses charged to operations	(23)	7
Provision for loan losses recorded through the FDIC loss share receivable	(429)	138
Balance at the end of the period	14,956	16,851
Loans collectively evaluated for impairment	14,956	16,851
Loans:
Loans collectively evaluated for impairment	48,110	56,316
Total acquired loans	48,110	56,316
Acquired loans | Commercial Real Estate
Allowance for loan losses:
Balance at the beginning of the period	1,517	1,318
Provision for loan losses before benefit attributable to FDIC loss share agreements	(675)	73
Benefit attributable to FDIC loss share agreements	526	(69)
Total provision for loan losses charged to operations	(149)	4
Provision for loan losses recorded through the FDIC loss share receivable	(526)	69
Balance at the end of the period	842	1,391
Loans collectively evaluated for impairment	842	1,391
Loans:
Loans collectively evaluated for impairment	347,238	100,797
Total acquired loans	347,238	100,797
Acquired loans | Commercial Real Estate - Construction and Development
Allowance for loan losses:
Balance at the beginning of the period	1,628
Provision for loan losses before benefit attributable to FDIC loss share agreements	856	2,057
Benefit attributable to FDIC loss share agreements	(686)	(1,666)
Total provision for loan losses charged to operations	170	391
Provision for loan losses recorded through the FDIC loss share receivable	686	1,666
Balance at the end of the period	2,484	2,057
Loans collectively evaluated for impairment	2,484	2,057
Loans:
Loans collectively evaluated for impairment	110,059	44,339
Total acquired loans	110,059	44,339
Acquired loans | Residential Real Estate
Allowance for loan losses:
Balance at the beginning of the period	4,616	5,471
Provision for loan losses before benefit attributable to FDIC loss share agreements	(55)	(1,136)
Benefit attributable to FDIC loss share agreements	290	1,079
Total provision for loan losses charged to operations	235	(57)
Provision for loan losses recorded through the FDIC loss share receivable	(290)	(1,079)
Balance at the end of the period	4,561	4,335
Loans collectively evaluated for impairment	4,561	4,335
Loans:
Loans collectively evaluated for impairment	336,030	129,189
Total acquired loans	336,030	129,189
Acquired loans | Consumer
Allowance for loan losses:
Balance at the beginning of the period	96
Provision for loan losses before benefit attributable to FDIC loss share agreements	(7)	10
Benefit attributable to FDIC loss share agreements	7	(9)
Total provision for loan losses charged to operations		1
Provision for loan losses recorded through the FDIC loss share receivable	(7)	9
Balance at the end of the period	89	10
Loans collectively evaluated for impairment	89	10
Loans:
Loans collectively evaluated for impairment	13,168	8,583
Total acquired loans	13,168	8,583
Acquired loans | Commercial & Industrial
Allowance for loan losses:
Balance at the beginning of the period	4,305	4,564
Provision for loan losses before benefit attributable to FDIC loss share agreements	(522)	19
Benefit attributable to FDIC loss share agreements	496	(18)
Total provision for loan losses charged to operations	(26)	1
Provision for loan losses recorded through the FDIC loss share receivable	(496)	18
Balance at the end of the period	3,783	4,583
Loans collectively evaluated for impairment	3,783	4,583
Loans:
Loans collectively evaluated for impairment	65,684	24,520
Total acquired loans	65,684	24,520
Acquired loans | Single Pay
Allowance for loan losses:
Balance at the beginning of the period		3,561	4,562
Provision for loan losses before benefit attributable to FDIC loss share agreements		1,567
Benefit attributable to FDIC loss share agreements		(1,489)
Total provision for loan losses charged to operations		78
Provision for loan losses recorded through the FDIC loss share receivable		1,489
Balance at the end of the period	4,562	5,128	4,562
Loans collectively evaluated for impairment	4,562	5,128
Loans:
Loans collectively evaluated for impairment	4,732	5,400
Total acquired loans	4,732	5,400
Acquired loans | FASB ASC Topic 310-20 Loans
Loans:
Loans collectively evaluated for impairment	70,234
Total acquired loans	$ 70,234	$ 73,215	$ 73,215