CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 30.2	$ 20.7	$ 145.7	$ 21.5
Other comprehensive income, net of tax
Pension and postretirement benefits, net of tax of $(1.2), $(3.5), $(3.2) and $(17.4), respectively	2.1	5.7	6.7	28.8
Net gain on derivative instruments, net of tax of $(2.7), $(4.3), $(13.2) and $(13.2), respectively	1.3	7.2	24.4	21.8
Foreign currency translation	3.7	2.6	4.0	(2.1)
Other comprehensive income	7.1	15.5	35.1	48.5
Comprehensive income	$ 37.3	$ 36.2	$ 180.8	$ 70.0