Annual report pursuant to Section 13 and 15(d)

Redeemable Convertible Preferred Stock - Schedule of Changes in the Preferred Stock (Detail)

v3.19.1
Redeemable Convertible Preferred Stock - Schedule of Changes in the Preferred Stock (Detail)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
USD ($)
Temporary Equity [Line Items]  
Beginning balance $ 25,871
Deemed dividends on preferred stock 958
Conversion Of Preferred Stock In To Common Stock Upon Merger (26,829)
Ending balance 0
Series A Preferred  
Temporary Equity [Line Items]  
Beginning balance 3,889
Deemed dividends on preferred stock 119
Conversion Of Preferred Stock In To Common Stock Upon Merger (4,008)
Ending balance 0
Series B Preferred  
Temporary Equity [Line Items]  
Beginning balance 5,480
Deemed dividends on preferred stock 178
Conversion Of Preferred Stock In To Common Stock Upon Merger (5,658)
Ending balance 0
Series C Preferred  
Temporary Equity [Line Items]  
Beginning balance 16,502
Deemed dividends on preferred stock 661
Conversion Of Preferred Stock In To Common Stock Upon Merger (17,163)
Ending balance $ 0