Reclassifications from Accumulated Other Comprehensive (Loss) Income - Schedule of Changes in AOCI by Component, Net of Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	$ 1,445.7	$ 1,520.1
Other comprehensive income before reclassifications	189.4	(48.9)
Amounts reclassified from AOCI	16.3	2.7
Net current-period other comprehensive income (loss)	205.7	(46.2)
Balances, end of period	1,392.3	1,445.7
Accumulated Other Comprehensive (Loss) Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	(398.0)	(351.8)
Balances, end of period	(192.3)	(398.0)
Cash flow hedging items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	(11.1)	(14.8)
Other comprehensive income before reclassifications	23.3	13.3
Amounts reclassified from AOCI	(5.3)	(9.6)
Net current-period other comprehensive income (loss)	18.0	3.7
Balances, end of period	6.9	(11.1)
Pension and other postretirement benefit plan items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	(334.3)	(293.3)
Other comprehensive income before reclassifications	153.6	(53.3)
Amounts reclassified from AOCI	21.6	12.3
Net current-period other comprehensive income (loss)	175.2	(41.0)
Balances, end of period	(159.1)	(334.3)
Foreign currency items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	(52.6)	(43.7)
Other comprehensive income before reclassifications	12.5	(8.9)
Amounts reclassified from AOCI	0.0	0.0
Net current-period other comprehensive income (loss)	12.5	(8.9)
Balances, end of period	$ (40.1)	$ (52.6)