Derivative Instruments (Summary Of Notional Amounts For Foreign Currency Contracts) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives designated as hedging instruments	$ 23,380	$ 33,219
Notional amount for foreign currency derivatives not designated as hedging instruments	62,479	71,353
Australian Dollar [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives designated as hedging instruments	2,642	4,078
Notional amount for foreign currency derivatives not designated as hedging instruments	8,539	8,138
Canadian Dollar [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives designated as hedging instruments	8,415	14,158
Chinese Yuan [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives designated as hedging instruments	1,747	2,777
Israeli Shekel [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives designated as hedging instruments	2,370	3,773
Russian Ruble [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives designated as hedging instruments	5,012	8,433
British Pound [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives not designated as hedging instruments	6,355	7,950
Euro [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives designated as hedging instruments	3,194
Notional amount for foreign currency derivatives not designated as hedging instruments	33,303	40,397
Danish Krone [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,255	891
Norwegian Krone [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,774	1,073
Swedish Krona [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives not designated as hedging instruments	1,359	446
South Korean Won [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives not designated as hedging instruments	2,217	2,193
Brazil Real [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives not designated as hedging instruments	3,988	3,826
Japanese Yen [Member]
Derivatives, Fair Value [Line Items]
Notional amount for foreign currency derivatives not designated as hedging instruments	$ 3,689	$ 6,439