Derivative Financial Instruments (Summary Of Derivative Financial Instruments Notional Amounts On Outstanding Positions) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Total notional value	$ 239,684	$ 328,221
Derivative fair value	2,753	(157)
Japanese Yen [Member]
Derivatives, Fair Value [Line Items]
Total notional value	64,840	87,171
Derivative fair value	1,722	4,180
Euro [Member]
Derivatives, Fair Value [Line Items]
Total notional value	53,732	94,763
Derivative fair value	611	(2,611)
Singapore Dollar [Member]
Derivatives, Fair Value [Line Items]
Total notional value	33,618	71,228
Derivative fair value	427	(1,441)
South Korean Won [Member]
Derivatives, Fair Value [Line Items]
Total notional value	16,243	14,332
Derivative fair value	38	(660)
British Pound Sterling [Member]
Derivatives, Fair Value [Line Items]
Total notional value	8,833	8,278
Derivative fair value	(4)	407
Other Currencies [Member]
Derivatives, Fair Value [Line Items]
Total notional value	62,418	52,449
Derivative fair value	$ (41)	$ (32)