CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 31.5	$ 23.4
Other comprehensive (loss) income, net of tax
Cumulative adjustment upon adoption of ASU 2017-12 reclassified to reinvested earnings	(1.0)	0.0
Pension and postretirement benefits, net of tax of $(0.5) and $(1.3), respectively	1.7	2.1
Net (loss) gain on derivative instruments, net of tax of $8.7 and $(4.9), respectively	(23.0)	8.1
Marketable securities gain, net of tax of $0.0 and $0.0, respectively	0.3	0.0
Foreign currency translation	0.7	1.8
Other comprehensive (loss) income	(21.3)	12.0
Comprehensive income	$ 10.2	$ 35.4