Derivative Instruments (Summary Of Notional Amounts For Foreign Currency Contracts) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Notional amount for foreign currency derivatives designated as hedging instruments	$ 25,811	$ 49,177
Notional amount for foreign currency derivatives not designated as hedging instruments	32,433	77,072
Australian Dollar [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	1,734	2,788
Notional amount for foreign currency derivatives not designated as hedging instruments	4,237	3,846
Canadian Dollar [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	5,981	7,694
Chinese Yuan [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	642	1,167
Israeli Shekel [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	1,245	2,105
Russian Ruble [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	4,264	6,206
British Pound [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	7,490	7,188
Notional amount for foreign currency derivatives not designated as hedging instruments	8,210	18,724
Euro [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	4,455	22,029
Notional amount for foreign currency derivatives not designated as hedging instruments	15,085	43,600
Danish Krone [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,156	2,126
Norwegian Krone [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,110	2,013
Swedish Krona [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	808	2,058
Brazil Real [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	$ 1,827	$ 4,705