Loans and Allowance for Loan Losses (Details 13) (USD $)	12 Months Ended
	Dec. 31, 2012 item	Dec. 31, 2011 item
Loans and Allowance for Loan Losses
Balance of accruing TDRs	$ 6,300,000	$ 5,800,000
Non-acquired loans
Loans and Allowance for Loan Losses
Number of loans	9	26
Pre-Modification Outstanding Recorded Investment	7,529,000	10,568,000
Post-Modification Outstanding Recorded Investment	7,359,000	10,005,000
Non-acquired loans | Interest rate modification
Loans and Allowance for Loan Losses
Number of loans	6	21
Pre-Modification Outstanding Recorded Investment	5,994,000	6,097,000
Post-Modification Outstanding Recorded Investment	5,835,000	5,621,000
Non-acquired loans | Interest rate modification | Construction and land development
Loans and Allowance for Loan Losses
Number of loans	1	15
Pre-Modification Outstanding Recorded Investment	165,000	3,595,000
Post-Modification Outstanding Recorded Investment	156,000	3,194,000
Non-acquired loans | Interest rate modification | Commercial owner occupied
Loans and Allowance for Loan Losses
Number of loans	4	2
Pre-Modification Outstanding Recorded Investment	5,355,000	1,334,000
Post-Modification Outstanding Recorded Investment	5,215,000	1,286,000
Non-acquired loans | Interest rate modification | Consumer owner occupied
Loans and Allowance for Loan Losses
Number of loans		2
Pre-Modification Outstanding Recorded Investment		759,000
Post-Modification Outstanding Recorded Investment		737,000
Non-acquired loans | Interest rate modification | Commercial and industrial
Loans and Allowance for Loan Losses
Number of loans	1
Pre-Modification Outstanding Recorded Investment	474,000
Post-Modification Outstanding Recorded Investment	464,000
Non-acquired loans | Interest rate modification | Other income producing property
Loans and Allowance for Loan Losses
Number of loans		2
Pre-Modification Outstanding Recorded Investment		409,000
Post-Modification Outstanding Recorded Investment		404,000
Non-acquired loans | Term modification
Loans and Allowance for Loan Losses
Number of loans	3	5
Pre-Modification Outstanding Recorded Investment	1,535,000	4,471,000
Post-Modification Outstanding Recorded Investment	1,524,000	4,384,000
Non-acquired loans | Term modification | Construction and land development
Loans and Allowance for Loan Losses
Number of loans	2	2
Pre-Modification Outstanding Recorded Investment	835,000	2,938,000
Post-Modification Outstanding Recorded Investment	824,000	2,929,000
Non-acquired loans | Term modification | Commercial non-owner occupied
Loans and Allowance for Loan Losses
Number of loans	1
Pre-Modification Outstanding Recorded Investment	700,000
Post-Modification Outstanding Recorded Investment	700,000
Non-acquired loans | Term modification | Commercial owner occupied
Loans and Allowance for Loan Losses
Number of loans		2
Pre-Modification Outstanding Recorded Investment		928,000
Post-Modification Outstanding Recorded Investment		864,000
Non-acquired loans | Term modification | Consumer owner occupied
Loans and Allowance for Loan Losses
Number of loans		1
Pre-Modification Outstanding Recorded Investment		605,000
Post-Modification Outstanding Recorded Investment		$ 591,000