Fair Value Of Financial Assets And Liabilities (Assets And Liabilities Measured At Fair Value On A Nonrecurring Basis) (Details) (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges	$ 0	$ 2,500,000	$ 2,500,000	$ 0
Remeasured plant assets		8,800,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)			$ 2,450,000