Pension and Other Postretirement Benefits (Details 9) - USD ($) $ in Millions	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Pension Plans
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	$ 985.8	$ 1,024.4	$ 930.2
Pension Plans | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	14.9	15.3
Pension Plans | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	158.9	142.1
Pension Plans | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	393.5	406.1
Pension Plans | Limited partnerships
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	38.4	52.0
Pension Plans | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	143.5	134.6
Pension Plans | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	225.8	248.1
Pension Plans | Mutual funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	1.5	2.9
Pension Plans | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	9.3	23.3
Pension Plans | Level 1
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	221.2	214.5
Pension Plans | Level 1 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Pension Plans | Level 1 | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	158.9	142.1
Pension Plans | Level 1 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	58.6	64.7
Pension Plans | Level 1 | Limited partnerships
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Pension Plans | Level 1 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	2.2	4.8
Pension Plans | Level 1 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Pension Plans | Level 1 | Mutual funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	1.5	2.9
Pension Plans | Level 1 | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Pension Plans | Level 2
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	764.6	809.9
Pension Plans | Level 2 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	14.9	15.3
Pension Plans | Level 2 | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Pension Plans | Level 2 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	334.9	341.4
Pension Plans | Level 2 | Limited partnerships
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	38.4	52.0
Pension Plans | Level 2 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	141.3	129.8
Pension Plans | Level 2 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	225.8	248.1
Pension Plans | Level 2 | Mutual funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Pension Plans | Level 2 | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	9.3	23.3
Other Postretirement Plans
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	111.6	106.5	$ 93.2
Other Postretirement Plans | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	21.6	17.2
Other Postretirement Plans | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	63.1	61.2
Other Postretirement Plans | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	16.0	18.6
Other Postretirement Plans | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	8.6	6.8
Other Postretirement Plans | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	2.3	2.7
Other Postretirement Plans | Level 1
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Other Postretirement Plans | Level 1 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Other Postretirement Plans | Level 1 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Other Postretirement Plans | Level 1 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Other Postretirement Plans | Level 1 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Other Postretirement Plans | Level 1 | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	0.0	0.0
Other Postretirement Plans | Level 2
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	111.6	106.5
Other Postretirement Plans | Level 2 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	21.6	17.2
Other Postretirement Plans | Level 2 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	63.1	61.2
Other Postretirement Plans | Level 2 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	16.0	18.6
Other Postretirement Plans | Level 2 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	8.6	6.8
Other Postretirement Plans | Level 2 | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	$ 2.3	$ 2.7