Note 3 - Fair Value Measurements - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Millions	Dec. 31, 2016	Jun. 30, 2016
At Cost	$ 21.8	$ 20.7
Unrealized Gains		0.1
Unrealized (Losses)
Fair Value	21.8	20.8
Money Market Funds [Member]
At Cost	7.7	1.5
Unrealized Gains
Unrealized (Losses)
Fair Value	7.7	1.5
Corporate Note Securities [Member]
At Cost	9.4	2.9
Unrealized Gains		0.1
Unrealized (Losses)
Fair Value	9.4	3.0
US Government Agencies Debt Securities [Member]
At Cost		2.0
Unrealized Gains
Unrealized (Losses)
Fair Value		2.0
Commercial Paper [Member]
At Cost	3.0
Unrealized Gains
Unrealized (Losses)
Fair Value	3.0
US Treasury Securities [Member]
At Cost		7.0
Unrealized Gains
Unrealized (Losses)
Fair Value		7.0
Certificates of Deposit [Member]
At Cost	1.7	7.3
Unrealized Gains
Unrealized (Losses)
Fair Value	$ 1.7	$ 7.3

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=73527792&loc=d3e27161-111563

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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=73527792&loc=d3e27161-111563

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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=65884222&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=66010992&loc=d3e26626-111562

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