Note 6. Loans (Detail) (USD $)	6 Months Ended	18 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
Concentration Risk, Percentage	96.00%
Legal Lending Limit, Per Borrower	$ 19,700,000
Impaired Financing Receivable, Recorded Investment	52,821,614	52,821,614	48,513,606
Proceeds from Principal Repayments on Loans and Leases Held-for-investment		87,500,000
Including Troubled Debt Restructurings [Member]
Impaired Financing Receivable, Recorded Investment	52,800,000	52,800,000
Performing [Member]
Financing Receivable, Modifications, Recorded Investment	22,600,000	22,600,000
Credit Impaired [Member]
Schedule of Insured Financial Obligations with Credit Deterioration, Insured Contractual Payments Outstanding	55,700,000	55,700,000
Non Credit Impaired [Member]
Schedule of Insured Financial Obligations with Credit Deterioration, Insured Contractual Payments Outstanding	$ 63,300,000	$ 63,300,000
Minimum [Member]
Financing Receivable Loan Amortization Term	15	15
Maximum [Member]
Financing Receivable Loan Amortization Term	20	20