Derivative Financial Instruments (Summary Of Derivative Financial Instruments Notional Amounts On Outstanding Positions) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Total notional value	$ 259,168	$ 328,221
Derivative fair value	(1,294)	(157)
Japanese Yen [Member]
Derivatives, Fair Value [Line Items]
Total notional value	65,627	87,171
Derivative fair value	64	4,180
Singapore Dollar [Member]
Derivatives, Fair Value [Line Items]
Total notional value	34,747	94,763
Derivative fair value	103	(2,611)
Euro [Member]
Derivatives, Fair Value [Line Items]
Total notional value	55,018	71,228
Derivative fair value	(186)	(1,441)
British Pound Sterling [Member]
Derivatives, Fair Value [Line Items]
Total notional value	18,727	14,332
Derivative fair value	0	(660)
South Korean Won [Member]
Derivatives, Fair Value [Line Items]
Total notional value	17,739	8,278
Derivative fair value	(5)	407
Other Currencies [Member]
Derivatives, Fair Value [Line Items]
Total notional value	67,310	52,449
Derivative fair value	$ (1,270)	$ (32)