Derivative Financial Instruments (Summary Of Derivative Financial Instruments Notional Amounts On Outstanding Positions) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Total notional value	$ 192,369	$ 328,221
Derivative fair value	285	(157)
Euro [Member]
Derivatives, Fair Value [Line Items]
Total notional value	41,271	71,228
Derivative fair value	(159)	(1,441)
Japanese Yen [Member]
Derivatives, Fair Value [Line Items]
Total notional value	36,616	87,171
Derivative fair value	(25)	4,180
Singapore Dollar [Member]
Derivatives, Fair Value [Line Items]
Total notional value	31,689	94,763
Derivative fair value	245	(2,611)
South Korean Won [Member]
Derivatives, Fair Value [Line Items]
Total notional value	26,380	8,278
Derivative fair value	98	407
British Pound Sterling [Member]
Derivatives, Fair Value [Line Items]
Total notional value	6,195	14,332
Derivative fair value	73	(660)
Other Currencies [Member]
Derivatives, Fair Value [Line Items]
Total notional value	50,218	52,449
Derivative fair value	$ 53	$ (32)