Note 11 - Warrant Transactions (Details) - Modified Warrants Fair Value Assumptions	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Venture Lending & Leasing VI and VII [Member]
Note 11 - Warrant Transactions (Details) - Modified Warrants Fair Value Assumptions [Line Items]
Risk-free interest rate:	2.73%	3.24%
Expected term (years):	9 years 335 days	6 years 29 days
Expected volatility:	90.59%	94.07%
Allen, F. Stephen Series #2 and #3 [Member]
Note 11 - Warrant Transactions (Details) - Modified Warrants Fair Value Assumptions [Line Items]
Risk-free interest rate:	2.81%
Expected term (years):	8 years 266 days
Expected volatility:	100.75%