Other Current and Long-Term Assets (Schedule Of Other Long-term Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Other Assets, Noncurrent [Abstract]
Customer acquisition costs	$ 104,406	$ 98,117
Contract assets, net	72,721	66,226
Investment in long-term product supply arrangements	13,388	13,657
Deferred sales commissions	10,409	10,442
Deferred income taxes	7,575	8,100
Taxes receivable	11,543	14,960
Other assets	36,712	28,690
Other long-term assets	$ 256,754	$ 240,192