Derivative Instruments And Hedging (Schedule Of Notional Amounts Of Foreign Currency Derivative Sale, Purchase And Forward Fixed Interest Rate Swap Agreement Contracts) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Currency sold	$ 146,310	$ 120,637
Interest rate swaps	80,000	80,000
Euro [Member]
Currency sold	73,707	59,360
British Pound [Member]
Currency sold	25,108	21,144
Canadian Dollar [Member]
Currency sold	26,118	21,776
Australian Dollar [Member]
Currency sold	9,091	7,930
Japanese Yen [Member]
Currency sold	12,286	10,427
Swiss Franc [Member]
Currency purchased	$ 20,615	$ 12,542