Note 2. Fair Value of Financial Instruments (Detail) - Fair Value Measurements (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Financial Assets:
Cash and cash equivalents	$ 73,723	$ 51,630	$ 47,966	$ 59,751
Cash and cash equivalents	73,723	51,630
Securities available for sale	93,758	85,670
Securities available for sale	93,758	85,670
Securities held to maturity	24,269	22,848
Securities held to maturity	24,815	22,847
Federal Home Loan Bank stock	6,281	6,281
Loans	564,074	598,308
Loans	581,056	599,782
Accrued interest receivable	2,371	2,872
Accrued interest receivable	2,371	2,872
Financial liabilities:
Deposits	683,179	687,886
Deposits	685,480	690,607
Other borrowed funds	20,089	20,296
Other borrowed funds	20,574	20,565
Subordinated debentures	13,500	13,500
Subordinated debentures	10,304	11,085
Accrued interest payable	1,721	1,894
Accrued interest payable	1,721	1,894
Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Cash and cash equivalents	73,723
Financial liabilities:
Deposits	142,421
Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Securities available for sale	93,758
Securities held to maturity	11,917
Accrued interest receivable	554
Financial liabilities:
Deposits	543,059
Other borrowed funds	20,574
Subordinated debentures	10,304
Accrued interest payable	1,721
Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Securities held to maturity	12,898
Loans	581,056
Accrued interest receivable	$ 1,817