Annual report pursuant to Section 13 and 15(d)

Provision for Income Taxes - Schedule of Loss Before Provision for Income Taxes (Detail)

v3.19.1
Provision for Income Taxes - Schedule of Loss Before Provision for Income Taxes (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Income Taxes Disclosure [Line Items]    
Loss before provision for income taxes $ (61,082) $ (59,595)
United States of America [Member]    
Income Taxes Disclosure [Line Items]    
Loss before provision for income taxes (61,169) $ (59,595)
Foreign [Member]    
Income Taxes Disclosure [Line Items]    
Loss before provision for income taxes $ 87