Pension and Other Postretirement Benefits (Details 9) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Pension Plans
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	$ 930.2	$ 770.9	$ 710.2
Pension Plans | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	13.7	14.4
Pension Plans | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	281.8	237.9
Pension Plans | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	216.5	191.4
Pension Plans | Limited partnerships
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	137.9	95.9
Pension Plans | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	109.8	102.4
Pension Plans | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	149.8	102.1
Pension Plans | Mutual funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	2.5	10.1
Pension Plans | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	18.2	16.7
Pension Plans | Level 1
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	344.3	295.0
Pension Plans | Level 1 | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	281.8	237.9
Pension Plans | Level 1 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	52.1	40.4
Pension Plans | Level 1 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	7.9	6.6
Pension Plans | Level 1 | Mutual funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	2.5	10.1
Pension Plans | Level 2
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	585.9	475.9
Pension Plans | Level 2 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	13.7	14.4
Pension Plans | Level 2 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	164.4	151.0
Pension Plans | Level 2 | Limited partnerships
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	137.9	95.9
Pension Plans | Level 2 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	101.9	95.8
Pension Plans | Level 2 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	149.8	102.1
Pension Plans | Level 2 | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	18.2	16.7
Other Postretirement Plans
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	93.2	85.3	80.3
Other Postretirement Plans | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	14.2	5.8
Other Postretirement Plans | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	51.4	44.7
Other Postretirement Plans | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	15.9	15.9
Other Postretirement Plans | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	7.5	7.4
Other Postretirement Plans | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	4.2	11.5
Other Postretirement Plans | Level 2
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	93.2	85.3
Other Postretirement Plans | Level 2 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	14.2	5.8
Other Postretirement Plans | Level 2 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	51.4	44.7
Other Postretirement Plans | Level 2 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	15.9	15.9
Other Postretirement Plans | Level 2 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	7.5	7.4
Other Postretirement Plans | Level 2 | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	$ 4.2	$ 11.5