Other Current and Long-Term Assets (Schedule Of Other Current Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Other Assets, Noncurrent [Abstract]
Customer acquisition costs	$ 39,719	$ 39,329
Prepaid expenses	32,403	31,992
Contract assets, net	18,670	17,659
Taxes receivable	15,150	20,516
Deferred sales commissions	5,302	5,202
Other assets	17,085	10,284
Other current assets	$ 128,329	$ 124,982