Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 46.3	$ 99.4	$ 188.9
Other comprehensive income (loss), net of income taxes
Pension and other postretirement benefit plans activity	(6.8)	(0.8)	5.3
Unrealized foreign currency translation loss, net	(2.8)	(12.9)	0.0
Unrealized gain on interest rate swaps	0.0	0.0	4.2
Other comprehensive income (loss), net of income taxes	(9.6)	(13.7)	9.5
Comprehensive income	$ 36.7	$ 85.7	$ 198.4