Income Taxes (Schedule Of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Computed expected tax expense	$ 20,020	$ 3,458	$ 10,845
Foreign tax differential	(19,032)	(88)	(7,676)
State income tax expense, net of federal income tax benefit	191	310	220
Change in Federal tax rate	(16,945)
Subpart F income	683	711	597
Adjustment to contingent consideration	(429)	(634)
Increase in uncertain tax positions	61	36	17
Non-deductible stock-based compensation	218	155	134
Excess tax benefit related to stock-based compensation	(1,858)
Prior year true-ups	1,894
Change in valuation allowance		(15)	(152)
Other	336	(89)	267
Total income tax expense (benefit)	$ (14,861)	$ 3,844	$ 4,252