Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fair Value of Financial Instruments
Cost to assume off-balance sheet commitments and standby letters of credit as a percentage of notional amount	10.00%
Assets:
Securities available for sale	$ 84,066	$ 115,645
Federal Reserve Bank and FHLB stock, at cost	11,247	12,475
Other real estate owned	2,258	1,231	34
Accrued interest receivable	4,126	3,885
Liabilities:
FHLB advances	87,000
Off-balance sheet commitments and standby letters of credit
Notional Amount	131,450	73,053
Cost to Cede or Assume	13,145	7,305
Level 1
Assets:
Cash and cash equivalents	59,352	60,235
Securities available for sale	81,042	111,725
Federal Reserve Bank and FHLB stock, at cost	11,247	12,475
Loans held for investment, net		3,885
Accrued interest receivable	4,126
Liabilities:
Deposit accounts	548,101	402,005
FHLB advances	87,000
Accrued interest payable	142	147
Level 2
Assets:
Securities available for sale	2,072	2,929
Loans held for sale, net	3,681	787,918
Loans held for investment, net	1,046,853
Other real estate owned	2,258	1,231
Liabilities:
Deposit accounts	363,382	431,236
FHLB advances		31,361
Other borrowings	31,267	5,405
Subordinated debentures	4,973
Off-balance sheet commitments and standby letters of credit
Cost to Cede or Assume	13,145	7,305
Level 3
Assets:
Securities available for sale	952	991
Loans held for investment, net	2,736	6,991
Carrying Amount
Assets:
Cash and cash equivalents	59,352	60,235
Securities available for sale	84,066	115,645
Federal Reserve Bank and FHLB stock, at cost	11,247	12,475
Loans held for sale, net	3,681
Loans held for investment, net	974,213	730,067
Other real estate owned	2,258	1,231
Accrued interest receivable	4,126	3,885
Liabilities:
Deposit accounts	904,768	828,877
FHLB advances	87,000
Other borrowings	28,500	28,500
Subordinated debentures	10,310	10,310
Accrued interest payable	142	147
Estimated Fair Value
Assets:
Cash and cash equivalents	59,352	60,235
Securities available for sale	84,066	115,645
Federal Reserve Bank and FHLB stock, at cost	11,247	12,475
Loans held for sale, net	3,681
Loans held for investment, net	1,049,589	794,906
Other real estate owned	2,258	1,231
Accrued interest receivable	4,126	3,885
Liabilities:
Deposit accounts	911,483	833,241
FHLB advances	87,000
Other borrowings	31,267	31,361
Subordinated debentures	4,973	5,405
Accrued interest payable	$ 142	$ 147