Note 17 - Consolidated Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Total revenue	$ 0.6		$ 5.3		$ 1.7		$ 1.7		$ 4.1		$ 5.9		$ 13.9		$ 0.7		$ 9.3	$ 24.6	$ 68.7
Operating expenses	7.4		10.5		8.2		8.4		24.1		4.8		7.5		7.7
Net (loss) income	$ (7.1)		$ (5.2)		$ (6.5)		$ (6.6)		$ (19.9)		$ 1.2		$ 6.5		$ (6.9)		$ (25.4)	$ (19.1)	$ (11.0)
Basic (in dollars per share)	$ (0.18)	[1]	$ (0.14)	[1]	$ (0.17)	[1]	$ (0.17)	[1]	$ (0.55)	[1]	$ 0.02	[1]	$ 0.19	[1]	$ (0.20)	[1]	$ (0.66)	$ (0.54)	$ (0.35)
Diluted (in dollars per share)	$ (0.18)	[1]	$ (0.14)	[1]	$ (0.17)	[1]	$ (0.17)	[1]	$ (0.55)	[1]	$ 0.02	[1]	$ 0.19	[1]	$ (0.20)	[1]	$ (0.66)	$ (0.54)	$ (0.35)

[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.