Loans and Allowance for Loan Losses (Details 9) (Acquired loans, USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Loans and Allowance for Loan Losses
Total covered loans	$ 309,034	$ 394,495	$ 426,998
Non-covered loans	211,957	7,706	8,763
Commercial Loans Greater Than or Equal to $1 Million-CBT
Loans and Allowance for Loan Losses
Total covered loans	53,301	60,829	63,066
Commercial Loans Greater Than or Equal to $1 Million-CBT | Pass
Loans and Allowance for Loan Losses
Total covered loans	15,854	17,257	18,554
Commercial Loans Greater Than or Equal to $1 Million-CBT | Special mention
Loans and Allowance for Loan Losses
Total covered loans	3,462	5,164	6,234
Commercial Loans Greater Than or Equal to $1 Million-CBT | Substandard
Loans and Allowance for Loan Losses
Total covered loans	33,985	38,408	38,278
Commercial real estate
Loans and Allowance for Loan Losses
Total covered loans	74,757	107,465	115,889
Non-covered loans	76,687	862	917
Commercial real estate | Pass
Loans and Allowance for Loan Losses
Total covered loans	24,992	33,770	37,268
Non-covered loans	60,774	799	866
Commercial real estate | Special mention
Loans and Allowance for Loan Losses
Total covered loans	12,505	22,089	23,971
Non-covered loans	5,243	38	37
Commercial real estate | Substandard
Loans and Allowance for Loan Losses
Total covered loans	37,095	51,108	54,150
Non-covered loans	10,670	25	14
Commercial real estate | Doubtful
Loans and Allowance for Loan Losses
Total covered loans	165	498	500
Commercial Real Estate - Construction & Land Development
Loans and Allowance for Loan Losses
Total covered loans	36,435	50,953	60,610
Non-covered loans	21,882	52	76
Commercial Real Estate - Construction & Land Development | Pass
Loans and Allowance for Loan Losses
Total covered loans	7,427	11,791	12,000
Non-covered loans	13,924	47	48
Commercial Real Estate - Construction & Land Development | Special mention
Loans and Allowance for Loan Losses
Total covered loans	4,875	5,947	7,927
Non-covered loans	2,206
Commercial Real Estate - Construction & Land Development | Substandard
Loans and Allowance for Loan Losses
Total covered loans	22,639	30,566	37,903
Non-covered loans	5,752	5	28
Commercial Real Estate - Construction & Land Development | Doubtful
Loans and Allowance for Loan Losses
Total covered loans	1,494	2,649	2,780
Residential Real Estate
Loans and Allowance for Loan Losses
Total covered loans	109,377	129,590	134,525
Non-covered loans	96,064	1,183	943
Residential Real Estate | Pass
Loans and Allowance for Loan Losses
Total covered loans	42,101	51,223	57,168
Non-covered loans	85,173	795	765
Residential Real Estate | Special mention
Loans and Allowance for Loan Losses
Total covered loans	22,314	19,827	19,735
Non-covered loans	5,008	22
Residential Real Estate | Substandard
Loans and Allowance for Loan Losses
Total covered loans	44,529	55,202	54,609
Non-covered loans	5,883	366	178
Residential Real Estate | Doubtful
Loans and Allowance for Loan Losses
Total covered loans	433	3,338	3,013
Consumer
Loans and Allowance for Loan Losses
Total covered loans	4,957	5,096	8,006
Non-covered loans	5,168	2,800	3,766
Consumer | Pass
Loans and Allowance for Loan Losses
Total covered loans	2,437	3,123	4,002
Non-covered loans	4,699	2,378	3,125
Consumer | Special mention
Loans and Allowance for Loan Losses
Total covered loans	703	445	878
Non-covered loans	256	146	207
Consumer | Substandard
Loans and Allowance for Loan Losses
Total covered loans	1,784	1,526	2,607
Non-covered loans	213	276	434
Consumer | Doubtful
Loans and Allowance for Loan Losses
Total covered loans	33	2	519
Commercial & Industrial
Loans and Allowance for Loan Losses
Total covered loans	25,343	36,502	40,960
Non-covered loans	12,156	2,809	3,061
Commercial & Industrial | Pass
Loans and Allowance for Loan Losses
Total covered loans	8,231	9,007	12,667
Non-covered loans	8,813	2,201	2,363
Commercial & Industrial | Special mention
Loans and Allowance for Loan Losses
Total covered loans	4,278	6,963	8,357
Non-covered loans	1,003	332	370
Commercial & Industrial | Substandard
Loans and Allowance for Loan Losses
Total covered loans	12,779	19,476	18,787
Non-covered loans	2,340	276	328
Commercial & Industrial | Doubtful
Loans and Allowance for Loan Losses
Total covered loans	55	1,056	1,149
Single Pay
Loans and Allowance for Loan Losses
Total covered loans	4,864	4,060	3,942
Single Pay | Pass
Loans and Allowance for Loan Losses
Total covered loans	1,881	465	468
Single Pay | Special mention
Loans and Allowance for Loan Losses
Total covered loans	52	62	62
Single Pay | Substandard
Loans and Allowance for Loan Losses
Total covered loans	$ 2,931	$ 3,533	$ 3,412