XML 54 R44.htm IDEA: XBRL DOCUMENT v3.10.0.1
Revenue From Contracts With Customers - Schedule of Deferred Revenue by Arrangement (Detail)
$ in Thousands
9 Months Ended
Sep. 30, 2018
USD ($)
Change In Contract With Customer Liability [Abstract]  
Beginning balance, January 1 $ 14,448
Amount of deferred revenue recognized in income (15,846)
Additions to deferred revenue 13,869
Ending balance, September 30 $ 12,471