Pension and Other Postretirement Benefits - Schedule of Amounts Recognized in the Consolidated Balance Sheets (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Pension Benefits
Amounts recognized in accumulated other comprehensive loss:
Net actuarial loss	$ 451.3	$ 547.7
Prior service cost (credit)	18.3	2.0
Total	469.6	549.7
Other changes in plan assets and benefit obligations recognized in other comprehensive loss consist of:
Net actuarial (gain) loss	(59.1)	152.8
Amortization of net loss	(37.8)	(27.3)
Prior service cost	18.6	0.0
Amortization of prior service (cost) benefit	(1.8)	(0.4)
Total, before tax effect	(80.1)	125.1
Additional information:
Accumulated benefit obligation for all pension plans	1,362.8	1,319.7
Other Benefits
Amounts recognized in accumulated other comprehensive loss:
Net actuarial loss	52.2	61.1
Prior service cost (credit)	(28.2)	(45.4)
Total	24.0	15.7
Other changes in plan assets and benefit obligations recognized in other comprehensive loss consist of:
Net actuarial (gain) loss	(5.7)	11.3
Amortization of net loss	(3.2)	(2.6)
Prior service cost	10.7	0.0
Amortization of prior service (cost) benefit	6.5	6.5
Total, before tax effect	$ 8.3	$ 15.2