Other Non-Operating Expenses, Net - Components of Other Non-Operating (Income) Expenses, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Other Income and Expenses [Abstract]
Investment (gains) losses, net	$ 1.6	$ 1.5	$ 2.9	$ 2.4
Foreign currency exchange (gain) loss	0.1	0.0	(0.3)	(0.3)
Other (gains) losses, net	1.5	0.8	1.7	1.6
Other non-operating expenses, net	$ 3.2	$ 2.2	$ 4.4	$ 3.7