Derivative Financial Instruments Fair Value of Derivative Instruments (Details) (Foreign Exchange Contract [Member], Not Designated as Hedging Instrument [Member], Other Assets [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Current derivative asset	$ 624	$ 312	$ 940
Current derivative liability	$ 431	$ 16	$ 633