Note 4. Loans and Allowance for Loan Losses (Detail) - Recorded Investment of Nonaccrual Loans and Loans Past Due 90 days (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Loans past due 90 days and still accruing	$ 265	$ 459
Nonaccrual	5,083	2,678
Residential Real Estate Loans [Member]
Loans past due 90 days and still accruing	187	439
Nonaccrual	2,494	2,536
Commercial Real Estate Owner Occupied [Member]
Nonaccrual	38	125
Commercial Real Estate Nonowner Occupied [Member]
Nonaccrual	959
Construction [Member]
Nonaccrual	1,574
Automobile Loans [Member]
Loans past due 90 days and still accruing	22	13
Nonaccrual	11	12
Home Equity Loans [Member]
Nonaccrual	5	5
Other Consumer Loans [Member]
Loans past due 90 days and still accruing	56	7
Nonaccrual	$ 2