Note 3 - Fair Value Measurements - Summary of Investments (Details) - USD ($) $ in Millions	Sep. 30, 2016	Jun. 30, 2015
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Available for Sale Securities - Current	$ 9.4	$ 1.5
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Available for Sale Securities - Current
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Available for Sale Securities - Current
Money Market Funds [Member]
Available for Sale Securities - Current	9.4	1.5
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Available for Sale Securities - Current	6.0	10.0
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Available for Sale Securities - Current	6.4	9.3
Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Available for Sale Securities - Current
Short-term Investments [Member]
Available for Sale Securities - Current	12.4	19.3
Fair Value, Inputs, Level 1 [Member]
Total	15.4	11.5
Fair Value, Inputs, Level 2 [Member]
Total	6.4	9.3
Fair Value, Inputs, Level 3 [Member]
Total
Available for Sale Securities - Current	21.8	20.8
Total	$ 21.8	$ 20.8