Acquisitions and FDIC Indemnification Asset (Details Textual) (USD $)	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended				6 Months Ended			12 Months Ended			6 Months Ended		6 Months Ended
	Jul. 31, 2009	Jun. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Mar. 31, 2013	Dec. 31, 2011	Jul. 02, 2009	Jun. 30, 2013 Commercial And Single Family Residential Mortgage Loans [Member] Minimum [Member]	Jun. 30, 2013 Commercial And Single Family Residential Mortgage Loans [Member] Maximum [Member]	Jun. 30, 2013 First National Bank Of Danville [Member]	Dec. 31, 2009 First National Bank Of Danville [Member]	Jul. 02, 2009 First National Bank Of Danville [Member]	Jul. 02, 2009 First National Bank Of Danville [Member] ASC 310-30 Loans [Member]	Jun. 30, 2013 Bank Of Amercia [Member]	Mar. 18, 2013 Bank Of Amercia [Member]	Jun. 30, 2013 After Acquisition [Member] Commercial And Single Family Residential Mortgage Loans [Member] Minimum [Member]	Jun. 30, 2013 After Acquisition [Member] Commercial And Single Family Residential Mortgage Loans [Member] Maximum [Member]
Liabilities												$ 146,300,000
Cash and cash equivalents												31,000,000
Customer related core deposit intangible asset												4,600,000
Estimated fair value of the loans							60,700,000						16,700,000
Contractually required payments receivable							58,400,000						31,600,000
Fair value of assets												151,800,000			2,300,000
Cash received (disbursed) from purchase of business unit	14,600,000
Gain on acquisition											5,100,000
Allowance for credit losses		559,000	559,000										18,400,000
Loans												77,500,000
Investment securities												24,200,000
Deposits payable												145,700,000			250,000,000
Losses on assets, threshold under loss-sharing agreement											29,000,000
Percentage of losses to be reimbursed by the FDIC, on losses up to the threshold amount											80.00%
Percentage of losses to be reimbursed by the FDIC, on losses exceeding the threshold amount											95.00%
Percentage of loans, acquired and subject to the loss-sharing agreement with the FDIC, which were included in the estimate of future potential losses										80.00%
Reimbursements from the FDIC		127,000	287,000	2,174,000						18,100,000
Outstanding balance for reimbursement of losses		1,515,000	1,515,000	2,632,000	1,770,000	2,384,000				1,500,000
Net changes in losses and expenses added		$ 128,000	$ 830,000	$ (2,422,000)						$ 469,000
Business Acquisition Purchase Price Allocation Liabilities Assumed Deposit Premium														2.75%
Loss Sharing Provisions Period								5 years	10 years							8 years	10 years