XML 73 R60.htm IDEA: XBRL DOCUMENT

Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Revenue Disclosure [Abstract]
Short-term deferred revenue	$ 86,100	$ 87,500
Deferred service revenue, cost of sales, current	16,900	14,200
Long-term deferred revenue	$ 17,244	$ 17,051