International Retirement Plan (Summary Of Amounts Recognized In Consolidated Balance Sheets) (Details) - International Retirement Plan [Member] - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Accrued liabilities	$ 144	$ 114
Other liabilities	8,290	7,613
Projected benefit obligation	8,434	7,727	$ 6,328
Accumulated other comprehensive income	(2,555)	(2,775)
Total	$ 5,879	$ 4,952