Annual report pursuant to Section 13 and 15(d)

Condensed Financial Statements - Summary of Components of Interest, Net (Detail)

v3.19.1
Condensed Financial Statements - Summary of Components of Interest, Net (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Condensed Financial Information Disclosure [Abstract]      
Interest expense $ (1,257) $ (261) $ (5)
Interest income 1,521 260  
Interest, net $ 264 $ (1) $ (5)