XML 37 R27.htm IDEA: XBRL DOCUMENT v3.5.0.2
Note 6 - Employee Stock Purchase Plan Valuation Assumptions (Details) - Employee Stock Purchase Plan 1997 [Member]
6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Risk-free interest rate 0.40% 0.10%
Dividend yield 0.00% 0.00%
Volatility 85.10% 59.10%
Expected life (years) 180 days 180 days