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Fair Value Measurements - Schedule of Fair Value of Financial Assets (Detail) - USD ($) $ in Millions		Sep. 30, 2016	Jun. 30, 2016
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets and liability		$ (2.0)	$ 162.4
Contingent Consideration
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial liability		(141.5)	(10.4)
Money Market Funds
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets	[1]	25.8	2.4
Corporate Bonds and Notes
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		45.5	51.0
Municipal Bonds
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		52.3	85.6
Federal Agency Issues
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		12.6	25.5
US Government Securities
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		3.3	8.3
Level 1
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets and liability		25.8	2.4
Level 1 | Money Market Funds
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets	[1]	25.8	2.4
Level 2
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets and liability		113.7	170.4
Level 2 | Corporate Bonds and Notes
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		45.5	51.0
Level 2 | Municipal Bonds
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		52.3	85.6
Level 2 | Federal Agency Issues
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		12.6	25.5
Level 2 | US Government Securities
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets		3.3	8.3
Level 3
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial assets and liability		(141.5)	(10.4)
Level 3 | Contingent Consideration
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Total fair value of financial liability		$ (141.5)	$ (10.4)
[1] Money market funds are primarily comprised of exchange traded funds and accrued interest

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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