Comprehensive Income (Schedule Of Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Comprehensive Income [Abstract]
Currency translation adjustment, Beginning Balance	$ 208	$ (1,543)
Currency translation adjustment, Current-period other comprehensive income (loss)	(2,924)	4,316
Currency translation adjustment, Income tax (expense) benefit	74	934
Currency translation adjustment, Ending Balance	(2,790)	1,839
Investments, Beginning Balance	(620)	(664)
Investments, Current-period other comprehensive income (loss)	(442)	1,293
Investments, Income tax (expense) benefit	11	280
Investments, Ending Balance	(1,073)	349
Derivative instruments, Beginning Balance	1,256	(1,293)
Derivative instruments, Current-period other comprehensive income (loss)	3,343	4,407
Derivative instruments, Reclassified from accumulated OCI into income	(1,265)	(523)
Derivative instruments, Income tax (expense) benefit	1,077	811
Derivative instruments, Ending Balance	2,257	1,780
Accumulated other comprehensive income, Beginning Balance	844	(3,500)
Accumulated other comprehensive income, Current-period other comprehensive income (loss)	(23)	10,016
Accumulated other comprehensive income, Reclassification from accumulated OCI into income	(1,265)	(523)
Tax provision related to items of other comprehensive income	1,162	2,025
Accumulated other comprehensive income, Ending Balance	$ (1,606)	$ 3,968