Pension and Other Postretirement Benefits (Details 9) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010
Pension Plans
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	$ 770.9	$ 710.2	$ 631.5
Pension Plans | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	14.4	10.5
Pension Plans | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	237.9	252.7
Pension Plans | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	191.4	286.8
Pension Plans | Limited partnerships
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	95.9
Pension Plans | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	102.4	65.6
Pension Plans | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	102.1	76.0
Pension Plans | Mutual funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	10.1
Pension Plans | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	16.7	18.6
Pension Plans | Level 1
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	295.0	434.2
Pension Plans | Level 1 | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	237.9	252.0
Pension Plans | Level 1 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	40.4	40.6
Pension Plans | Level 1 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	6.6	65.6
Pension Plans | Level 1 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets		76.0
Pension Plans | Level 1 | Mutual funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	10.1
Pension Plans | Level 2
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	475.9	276.0
Pension Plans | Level 2 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	14.4	10.5
Pension Plans | Level 2 | Domestic and international equities
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets		0.7
Pension Plans | Level 2 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	151.0	246.2
Pension Plans | Level 2 | Limited partnerships
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	95.9
Pension Plans | Level 2 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	95.8
Pension Plans | Level 2 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	102.1
Pension Plans | Level 2 | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	16.7	18.6
Other Postretirement Plans
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	85.3	80.3	63.2
Other Postretirement Plans | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	5.8	14.5
Other Postretirement Plans | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	44.7	43.9
Other Postretirement Plans | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	15.9	16.0
Other Postretirement Plans | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	7.4	5.9
Other Postretirement Plans | Mortgage/ asset backed securities and other
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	11.5
Other Postretirement Plans | Level 1
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets		21.9
Other Postretirement Plans | Level 1 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets		16.0
Other Postretirement Plans | Level 1 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets		5.9
Other Postretirement Plans | Level 2
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	85.3	58.4
Other Postretirement Plans | Level 2 | Short-term investments
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	5.8	14.5
Other Postretirement Plans | Level 2 | Commingled funds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	44.7	43.9
Other Postretirement Plans | Level 2 | Government agency bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	15.9
Other Postretirement Plans | Level 2 | Corporate bonds
Pension and Other Postretirement Benefit Disclosures
Fair value of pension plan assets	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	$ 11.5