Note 7 - Common Stock - Reserved for Future Issuances Shares of Common Stock (Details) - shares	Jun. 30, 2015	Dec. 31, 2014
Performance Shares [Member]
Reserved for Future Issuance (in shares)	2,461,157	1,807,349
The 2014 Employee Stock Purchase Plan [Member]
Reserved for Future Issuance (in shares)	299,127	140,500
Reserved for Future Issuance (in shares)	2,760,284	1,947,849