Pension and Other Postretirement Benefits - Schedule of Accumulated Benefit Obligations in Excess of Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 31.2	$ 32.2	$ 32.1
Interest cost	58.0	54.1	57.5
Expected return on plan assets	(66.1)	(68.8)	(62.9)
Amortization of net loss	27.4	16.7	21.8
Amortization of prior service cost (benefit)	0.4	0.3	0.5
Curtailment gain	0.0	0.0	0.0
Net periodic benefit costs	50.9	34.5	49.0
Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	3.3	4.4	4.0
Interest cost	10.4	11.8	12.5
Expected return on plan assets	(7.0)	(6.6)	(6.5)
Amortization of net loss	2.7	2.0	1.2
Amortization of prior service cost (benefit)	(6.5)	0.0	(0.1)
Curtailment gain	0.0	(1.6)	0.0
Net periodic benefit costs	$ 2.9	$ 10.0	$ 11.1