Note 1 - Organization and Summary of Significant Accounting Policies (Detail) (USD $)	12 Months Ended		253 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012
Number of Operating Segments	2
Available-for-sale Securities, Amortized Cost Basis (in Dollars)	$ 264,000		$ 264,000
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax (in Dollars)	6,000		6,000
Inventory Valuation Reserves (in Dollars)	78,000	76,000	78,000
Depreciation (in Dollars)	476,000	391,000
Operating Leases, Income Statement, Lease Revenue (in Dollars)	2,231,000	2,067,000
Operating Leases, Future Minimum Payments Receivable (in Dollars)	120,000	402,000	120,000
Cost-method Investments, Other than Temporary Impairment (in Dollars)	17,000
Number of Investments, Cost Method, Impaired During the Period	1
Equity Method Investments (in Dollars)	892,000	905,000	892,000
Cost Method Investments (in Dollars)	667,000	383,000	667,000
Finite-Lived Intangible Asset, Useful Life	10 years
Fair Value Hierarchy, Number of Levels	3		3
Software Arrangements, Number of Categories	4		4
Deferred Revenue, Current, Term	12 months		12 months
Product Warranty Accrual (in Dollars)	164,000	136,000	164,000
Allocated Share-based Compensation Expense (in Dollars)	79,000	43,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)	17,000	164,500	1,198,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in Dollars per share)	$ 1.28	$ 1.25
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options (in Dollars)	$ 113,000		$ 113,000
Notes Receivable [Member]
Fair Value Inputs, Discount Rate	4.00%
2011 Non-Employee Directors Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)	17,000	12,000
2003 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in Shares)	152,500
Minimum [Member]
Equity Method Investment, Ownership Percentage	20.00%		20.00%
Maximum [Member]
Equity Method Investment, Ownership Percentage	50.00%		50.00%