Derivatives and Hedging Activities - Schedule of Changes in AOCI Associated with Derivative Hedging Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	$ 1,445.7	$ 1,520.1	$ 1,485.9
Balances, end of period	1,392.3	1,445.7	1,520.1
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	(11.1)	(14.8)	23.8
Current period changes in fair value, net of tax	23.3	13.3	(32.7)
Reclassification to earnings, net of tax	(5.3)	(9.6)	(4.9)
Balances, end of period	6.9	(11.1)	(14.8)
Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period			0.0
Cumulative Effect, Period of Adoption, Adjustment | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances, beginning of period	$ 0.0	0.0	(1.0)
Balances, end of period		$ 0.0	$ 0.0