Other Income, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Other Income and Expenses [Abstract]
Interest income on corporate funds	$ (15.0)	$ (11.0)	$ (71.6)	$ (59.4)
Realized gains on available-for-sale securities	(0.6)	(1.3)	(1.2)	(1.9)
Realized losses on available-for-sale securities	0.5	1.6	2.6	3.2
Impairment of intangible assets	0.0	0.0	12.1	0.0
Gain on sale of assets	0.0	0.0	(4.1)	(0.4)
Non-service components of pension expense, net (see Note 2)	(5.9)	(16.5)	(5.3)	(49.4)
Other income, net	$ (21.0)	$ (27.2)	$ (67.5)	$ (107.9)