CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Pension and post-retirement benefits, tax (expense) benefit	$ (0.8)	$ (3.5)	$ (2.1)	$ (14.0)
Net loss on derivative instruments, tax expense (benefit)	$ (5.6)	$ (2.4)	$ (10.4)	$ (8.8)