Note 2 - Summary of significant accounting policies (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash and Highly Liquid Investments Maturity	90 days
Restricted Cash and Cash Equivalents (in Dollars)	1,577,920
Line of Credit Facility, Maximum Borrowing Capacity (in Dollars)	600,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	10,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)	3,000,000
Share-Based Compensation Arrangement By Share-Based Payment Award Number Of Shares Limited Per Year (in Shares)	400,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	10 years
Majority-Owned Subsidiaries [Member]
Restricted Cash and Cash Equivalents (in Dollars)	2,633,944
Cash and Cash Equivalents Located Outside United States [Member]
Concentration Risk, Percentage	30.00%
Short-Term Investments Located Outside United States [Member]
Concentration Risk, Percentage	100.00%
Minimum [Member]
Short-Term Investments Maturity	3 months
Maximum [Member]
Cash and Investments Maturity Term	1 year
Majority-Owned Subsidiaries [Member]
Subsidiary Cash Total (in Dollars)	7,706,936
Grant and Contract Revenue From USA [Member]
Concentration Risk, Percentage	34.80%	87.60%	100.00%
Short-Term Investments Located Outside United States [Member]
Concentration Risk, Percentage	65.20%	12.40%	0.00%
Accounts Receivable [Member]
Credit Term	30 days
Patents [Member]
Amortization of Intangible Assets (in Dollars)		1,500,000