Note 17 - Consolidated Quarterly Financial Information (Details) - USD ($) $ in Millions		3 Months Ended
		Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013
Total revenue		$ 4.1	$ 5.9	$ 13.9	$ 0.7	$ 8.5	$ 29.5	$ 18.5	$ 12.2
Operating expenses		24.1	4.8	7.5	7.7	19.0	26.3	18.6	16.3
Net (loss) income		$ (19.9)	$ 1.2	$ 6.5	$ (6.9)	$ (10.2)	$ 3.2	$ (0.1)	$ (3.9)
Basic (in dollars per share)	[1]	$ (0.55)	$ 0.02	$ 0.19	$ (0.20)	$ (0.29)	$ 0.09	$ 0	$ (0.15)
Diluted (in dollars per share)	[1]	$ (0.55)	$ 0.02	$ 0.19	$ (0.20)	$ (0.29)	$ 0.09	$ 0	$ (0.15)
Net loss		$ (19.9)	$ 1.2	$ 6.5	$ (6.9)	$ (10.2)	$ 3.2	$ (0.1)	$ (3.9)

[1] Due to the use of the weighted average shares outstanding for each quarter for computing earnings per share, the sum of the quarterly per share amounts may not equal the per share amount for the year.