CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (49.1)	$ (229.6)	$ 1.5
Other comprehensive income (loss), net of tax
Pension and postretirement benefits (losses), net of tax of $(8.4), $(55.3) and $(13.2), respectively	26.2	175.2	(41.0)
Net (loss) gain on derivative instruments, net of tax of $0.5, $(5.7) and $(1.2), respectively	(1.4)	18.0	3.7
Foreign currency translation	(6.0)	12.5	(8.9)
Other comprehensive income (loss), net of tax	18.8	205.7	(46.2)
Comprehensive loss, net of tax	$ (30.3)	$ (23.9)	$ (44.7)