Fair Value Measurements (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Jun. 30, 2012
Carrying Value
Carrying amounts and estimated fair values of financial instruments not recorded at fair value
Long-term debt, including current portion	$ 406.2	$ 406.9
Company-owned life insurance	13.8	11.0
Fair Value
Carrying amounts and estimated fair values of financial instruments not recorded at fair value
Company-owned life insurance	13.8	11.0
Fair Value | Level 2
Carrying amounts and estimated fair values of financial instruments not recorded at fair value
Long-term debt, including current portion	$ 433.4	$ 427.7