Derivative Financial Instruments (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivatives, Fair Value [Line Items]
Foreign currency forward contracts	$ 42,121	$ 71,930
Lead Hedge Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional amount	60,000	63,400
Cost Of Goods Sold [Member] | Foreign Currency Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Pretax gain reclassified from accumulated other comprehensive income	1,784
Not Designated As Hedging Instrument [Member] | Interest Rate Swap Agreements [Member]
Derivatives, Fair Value [Line Items]
Change in fair value recorded in other expense, net	977
Interest rate swap agreements converted into fixed rate basis	85,000	85,000
Not Designated As Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional amount	11,410
Change in fair value recorded in other expense, net	$ 106
Not Designated As Hedging Instrument [Member] | Minimum [Member] | Interest Rate Swap Agreements [Member]
Derivatives, Fair Value [Line Items]
Derivative, maturity date	Feb. 01, 2013
Not Designated As Hedging Instrument [Member] | Maximum [Member] | Interest Rate Swap Agreements [Member]
Derivatives, Fair Value [Line Items]
Derivative, maturity date	May 01, 2013