Note 3 - Short-term Financial Instruments - Financial Assets (Details) - USD ($) $ in Millions	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Financial assets:
Cash and cash equivalents	$ 17.7	$ 49.7	$ 44.7
Short-term investments	20.9	19.3
Accounts receivable, net of allowance	0.6	0.7
Total current financial assets	39.2	69.7
Financial liabilities:
Accounts payable and current accrued liabilities	4.3	7.5
Short-term note payable	0.2	0.4
Total current financial liabilities	4.5	7.9
Net financial assets	$ 34.7	$ 61.8