Note 6 - Common Stock (Details) - Reserved for Future Issuances Shares of Common Stock	Mar. 31, 2015	Dec. 31, 2014
Note 6 - Common Stock (Details) - Reserved for Future Issuances Shares of Common Stock [Line Items]
Shares reserved for future issuance	2,770,070	1,947,849
Performance Shares [Member]
Note 6 - Common Stock (Details) - Reserved for Future Issuances Shares of Common Stock [Line Items]
Shares reserved for future issuance	2,465,079	1,807,349
The 2014 Employee Stock Purchase Plan [Member]
Note 6 - Common Stock (Details) - Reserved for Future Issuances Shares of Common Stock [Line Items]
Shares reserved for future issuance	304,991	140,500