Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Abstract]
Computed expected tax expense	$ 23,651	$ 25,052	$ 25,935
Increase (decrease) in income taxes resulting from:
Foreign tax differential	(17,955)	(19,046)	(17,294)
State income tax expense, net of federal income tax benefit	55	(514)	(66)
Subpart F income	1,106	1,255	1,404
Increase (decrease) of uncertain tax liabilities	38	124	(78)
Non-deductible stock-based compensation	112	92	86
Change in valuation allowance	167
Other	17	94	(169)
Income Tax Expense (Benefit), Total	$ 7,191	$ 7,057	$ 9,818