Other Current and Long-Term Assets (Schedule of Other Current Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Other Assets, Noncurrent [Abstract]
Customer acquisition costs	$ 39,329		$ 34,515
Prepaid expenses (Note 2)	31,992		30,314
Taxes receivable	20,516		14,098
Contract assets	17,659		9,670
Deferred sales commissions	5,202		4,464
Other	10,284		15,159
Other current assets	$ 124,982	$ 107,228	$ 108,220