Pension and Other Postretirement Benefits - Schedule of Amounts Recognized in the Consolidated Balance Sheets (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Pension Benefits
Amounts recognized in accumulated other comprehensive loss:
Net actuarial loss	$ 445.7	$ 362.1
Prior service cost (credit)	14.1	16.2
Total	459.8	378.3
Other changes in plan assets and benefit obligations recognized in other comprehensive loss consist of:
Net actuarial loss (gain)	94.1	(75.0)
Amortization of net loss	(10.4)	(13.5)
Amortization of prior service (cost) benefit	(2.1)	(2.1)
Total, before tax effect	81.6	(90.6)
Additional information:
Accumulated benefit obligation for all pension plans	1,331.6	1,257.8
Other Benefits
Amounts recognized in accumulated other comprehensive loss:
Net actuarial loss	42.3	32.9
Prior service cost (credit)	(17.9)	(23.1)
Total	24.4	9.8
Other changes in plan assets and benefit obligations recognized in other comprehensive loss consist of:
Net actuarial loss (gain)	10.9	(16.3)
Amortization of net loss	(1.6)	(2.9)
Amortization of prior service (cost) benefit	5.2	5.2
Total, before tax effect	$ 14.5	$ (14.0)