XML 98 R87.htm IDEA: XBRL DOCUMENT v3.19.2
Revenues from Contracts with Customers - Additional Information (Detail) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Revenue From Contract With Customer [Abstract]    
Deferred revenue $ 2.5 $ 4.2
Deferred revenue, revenue recognized $ 1.2