Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accumulated Other Comprehensive Income [Abstract]
Beginning balance, Unrealized loss on investments, net of tax	$ (171)
Beginning balance, Unrealized gain on derivatives instruments, net of tax	(2,070)
Beginning balance, Unrealized gain on cumulative translation adjustment	18,195
Unrealized gain on investments, net of tax expense of $42 in 2013 and $65 in 2012	72	111
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	4,118	(906)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Gains Included in Net Income, Net of Tax	(10)	(795)
Translation Adjustment Functional to Reporting Currency, Net of Tax, Period Increase (Decrease)	(8,447)	5,628
Current-period other comprehensive income (loss), Unrealized (loss) gain on derivatives instruments, net of tax	4,108	(1,701)
Current-period other comprehensive income (loss), Unrealized gain (loss) on cumulative translation adjustment	(8,447)	5,628
OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	(4,257)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(10)
Ending balance, Unrealized loss on investments, net of tax	(99)
Ending balance, Unrealized loss on derivatives instruments, net of tax	2,038
Ending balance, Unrealized gain on cumulative translation adjustment	9,748
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	15,954
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	$ 11,687