Goodwill and Intangible Assets - Summarized Amounts Reported as Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Jun. 30, 2015
Intangible Assets [Line Items]
Gross Carrying Amount, amortizable intangible assets	$ 206.8	$ 206.8
Gross Carrying Amount, total intangible assets	211.6	211.6
Accumulated Amortization	(22.2)	(19.0)
Net, amortizable intangible assets	184.6	187.8
Net, total intangible assets	189.4	192.6
Net, non-amortizable intangible assets	4.8	4.8
In-Process Research and Development
Intangible Assets [Line Items]
Net, non-amortizable intangible assets	4.8	4.8
Purchased Licenses and Technologies
Intangible Assets [Line Items]
Gross Carrying Amount, amortizable intangible assets	199.1	199.1
Accumulated Amortization	(19.7)	(16.7)
Net, amortizable intangible assets	179.4	182.4
Customer Relationships
Intangible Assets [Line Items]
Gross Carrying Amount, amortizable intangible assets	4.7	4.7
Accumulated Amortization	(2.0)	(1.9)
Net, amortizable intangible assets	2.7	2.8
Trademarks
Intangible Assets [Line Items]
Gross Carrying Amount, amortizable intangible assets	3.0	3.0
Accumulated Amortization	(0.5)	(0.4)
Net, amortizable intangible assets	$ 2.5	$ 2.6