Employee Retirement Benefit Plans-Balance Sheet (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Retirement Benefits [Member]
Amounts Recognized in Statement of Financial Position
Noncurrent assets	$ 18.0	$ 2.7
Current liabilities	(0.8)	(0.8)
Noncurrent liabilities	(90.2)	(87.9)
Funded status at end of year	(73.0)	(86.0)
Amounts Recognized in Accumulated Other Comprehensive Income
Transition (asset)/obligation	0.0	0.0
Prior service cost	(0.5)	(0.5)
Net (gain)/loss	53.0	58.2
Total accumulated other comprehensive income at the end of the year	52.5	57.7
Additional Information for Plan with ABO in Excess of Plan Assets
Projected benefit obligation	157.8	153.1
Accumulated benefit obligation	152.1	147.5
Fair value of plan assets	66.7	64.5
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Projected Benefit Obligation	157.8	153.1
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Benefit Obligation	152.1	147.5
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets	66.7	64.5
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service Cost	3.5	3.2
Interest Cost	7.3	6.6
Expected return on plan assets	(11.9)	(11.0)
Transition (asset)/obligation	0.0	0.0
Prior service cost	0.0	0.0
Net (gain)/loss	2.4	4.4
Net periodic benefit cost	1.3	3.2
Other Post-Retirement Benefits [Member]
Amounts Recognized in Statement of Financial Position
Noncurrent assets	0.0	0.0
Current liabilities	(0.3)	(0.3)
Noncurrent liabilities	(2.5)	(2.5)
Funded status at end of year	(2.8)	(2.8)
Amounts Recognized in Accumulated Other Comprehensive Income
Transition (asset)/obligation	0.0	0.0
Prior service cost	0.0	0.0
Net (gain)/loss	(1.1)	(1.5)
Total accumulated other comprehensive income at the end of the year	(1.1)	(1.5)
Additional Information for Plan with ABO in Excess of Plan Assets
Projected benefit obligation	2.8	2.8
Accumulated benefit obligation	2.8	2.8
Fair value of plan assets	0.0	0.0
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Projected Benefit Obligation	2.8	2.8
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Benefit Obligation	2.8	2.8
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets	0.0	0.0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service Cost	0.0	0.0
Interest Cost	0.0	0.1
Expected return on plan assets	0.0	0.0
Transition (asset)/obligation	0.0	0.0
Prior service cost	0.0	0.0
Net (gain)/loss	(0.1)	(0.2)
Net periodic benefit cost	$ (0.1)	$ (0.1)