Derivative Instruments (Summary Of Notional Amounts For Foreign Currency Contracts) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Notional amount for foreign currency derivatives designated as hedging instruments	$ 20,564	$ 49,177
Notional amount for foreign currency derivatives not designated as hedging instruments	45,945	77,072
Japanese Yen [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,556
Australian Dollar [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	2,241	2,788
Notional amount for foreign currency derivatives not designated as hedging instruments	4,247	3,846
Canadian Dollar [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	7,619	7,694
Chinese Yuan [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	1,584	1,167
Israeli Shekel [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	1,264	2,105
Russian Ruble [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	5,362	6,206
British Pound [Member]
Notional amount for foreign currency derivatives designated as hedging instruments	2,494	7,188
Notional amount for foreign currency derivatives not designated as hedging instruments	8,118	18,724
Euro [Member]
Notional amount for foreign currency derivatives designated as hedging instruments		22,029
Notional amount for foreign currency derivatives not designated as hedging instruments	28,740	43,600
Danish Krone [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,157	2,126
Norwegian Krone [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,111	2,013
Swedish Krona [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	785	2,058
Brazil Real [Member]
Notional amount for foreign currency derivatives not designated as hedging instruments	$ 231	$ 4,705