Other Current and Long-Term Assets (Schedule Of Other Current Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Current and Long-Term Assets [Abstract]
Prepaid expenses	$ 28,233	$ 25,746
Taxes receivable	20,438	27,672
Customer acquisition costs, net	22,158	18,085
Other assets	12,881	19,703
Other current assets	$ 83,710	$ 91,206