Derivative Instruments and Hedging Activities - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivatives used in Net Investment Hedge, Increase (Decrease), Gross of Tax	$ 13.6	$ 2.5	$ 10.0	$ 2.5
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	10.2	$ 4.3	7.6	$ 4.3
Net accumulated gain related to investment hedges			91.4
Euro Denominated Debt Outstanding [Member]
Derivative [Line Items]
Total long-term debt	$ 717.1		$ 717.1