Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Computed expected tax expense	$ 10,928	$ 23,651	$ 25,052
Foreign tax differential	(7,676)	(17,955)	(19,046)
State income tax expense, net of federal income tax benefit	220	55	(514)
Subpart F income	597	1,106	1,255
Increase in uncertain tax positions	17	38	124
Non-deductible stock-based compensation	134	112	92
Change in valuation allowance	(152)	167
Other	184	17	94
Total income tax expense (benefit)	$ 4,252	$ 7,191	$ 7,057