Note 5 - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Millions	Jun. 30, 2015	Jun. 30, 2014
Money Market Funds [Member]
At Cost	$ 6.3	$ 36.9
Unrealized Gains
Unrealized (Losses)
Fair Value	$ 6.3	$ 36.9
US Government Agencies Debt Securities [Member]
At Cost	$ 6.5	$ 4.9
Unrealized Gains
Unrealized (Losses)
Fair Value	$ 6.5	$ 4.9
US Treasury Securities [Member]
At Cost	$ 9.6	$ 5.1
Unrealized Gains
Unrealized (Losses)	$ (0.1)
Fair Value	9.5	$ 5.1
Corporate Note Securities [Member]
At Cost	$ 2.9
Unrealized Gains
Unrealized (Losses)
Fair Value	$ 2.9
Certificates of Deposit [Member]
At Cost	$ 1.9
Unrealized Gains
Unrealized (Losses)
Fair Value	$ 1.9
At Cost	$ 27.2	$ 46.9
Unrealized Gains
Unrealized (Losses)	$ (0.1)
Fair Value	$ 27.1	$ 46.9

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26626-111562

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Amortized cost of short-term investments in debt and equity securities and other forms of securities that provide ownership interests classified as available-for-sale.

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