Note 6. Accounting for Stock-Based Compensation (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	24,000	27,000	24,000	40,000
Allocated Share-based Compensation Expense	$ 20,000	$ 44,000	$ 62,000	$ 112,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	0	0	136,000	150,000