Changes in Accumulated Other Comprehensive Income/(Loss) by Component - Summary of Changes in Accumulated Balances for Each Component of Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' equity at beginning of period			$ 1,045.5
Other comprehensive income/(loss) before reclassifications	$ 0.3	$ (9.8)	(22.7)	$ (27.0)
Amounts reclassified from accumulated other comprehensive income/(loss)	0.1	0.1	0.4	0.2
Stockholders' equity at end of period	942.3		942.3
Foreign Currency Translation
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' equity at beginning of period	(55.1)	(33.5)	(31.9)	(16.6)
Other comprehensive income/(loss) before reclassifications	0.0	(9.4)	(23.2)	(26.3)
Amounts reclassified from accumulated other comprehensive income/(loss)	0.0	0.0	0.0	0.0
Stockholders' equity at end of period	(55.1)	(42.9)	(55.1)	(42.9)
Available- for-Sale Securities
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' equity at beginning of period	1.5	1.7	1.3	2.0
Other comprehensive income/(loss) before reclassifications	0.3	(0.4)	0.5	(0.7)
Amounts reclassified from accumulated other comprehensive income/(loss)	0.0	0.0	0.0	0.0
Stockholders' equity at end of period	1.8	1.3	1.8	1.3
Pension and Post- Retirement Liabilities
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' equity at beginning of period	(7.3)	(6.2)	(7.6)	(6.3)
Other comprehensive income/(loss) before reclassifications	0.0	0.0	0.0	0.0
Amounts reclassified from accumulated other comprehensive income/(loss)	0.1	0.1	0.4	0.2
Stockholders' equity at end of period	(7.2)	(6.1)	(7.2)	(6.1)
AOCI Attributable to Parent
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Stockholders' equity at beginning of period	(60.9)	(38.0)	(38.2)	(20.9)
Stockholders' equity at end of period	$ (60.5)	$ (47.7)	$ (60.5)	$ (47.7)