Derivatives and Hedging Activities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Mar. 31, 2012
Commodity Derivatives [Member] | Designated as Hedging Instrument [Member] | Other current assets [Member]
Derivative, Fair Value, Net [Abstract]
Derivative Asset, Fair Value, Net,	$ 0	$ 0.2
Commodity Derivatives [Member] | Designated as Hedging Instrument [Member] | Other current liabilities [Member]
Derivative, Fair Value, Net [Abstract]
Derivative Asset, Fair Value, Net,	0	0.9
Commodity Derivatives [Member] | Not Designated as Hedging Instrument [Member] | Other current liabilities [Member]
Derivative, Fair Value, Net [Abstract]
Derivative Liability, Fair Value, Net	0.9	2.6
Commodity Derivatives [Member] | Not Designated as Hedging Instrument [Member] | Other noncurrent liabilities [Member]
Derivative, Fair Value, Net [Abstract]
Derivative Liability, Fair Value, Net	0.2	0
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Other current assets [Member]
Derivative, Fair Value, Net [Abstract]
Derivative Liability, Fair Value, Net	$ 0	$ 0.2