General form of registration statement for all companies including face-amount certificate companies

Summary of Significant Accounting Policies - Summary of Net Revenues (Detail)

v3.8.0.1
Summary of Significant Accounting Policies - Summary of Net Revenues (Detail) - USD ($)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Dec. 31, 2015
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]        
Total net revenues $ 10,914 $ 6,408 $ 8,911 $ 13,928
Media Agency Revenues [Member]        
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]        
Total net revenues 9,926 6,197 8,404 13,887
SaaS Revenues [Member]        
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]        
Total net revenues $ 988 $ 211 $ 507 $ 41