Derivative Instruments (Effect Of Derivative Instruments Designated As Hedges On AOCI) (Details) (Foreign Currency Contracts [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in AOCI (effective portion)	$ 709	$ (407)
Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain reclassified from accumulated AOCI (effective portion)	(118)	(1,030)
Operating Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (loss) gain reclassified from accumulated AOCI (effective portion)	$ 340	$ 500