Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.8.0.1
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
$ in Thousands
 1 Months Ended 3 Months Ended 9 Months Ended
May 17, 2017
May 31, 2017
Mar. 31, 2017
Aug. 31, 2016
Jun. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Gross media placements           $ 30,270 $ 18,872 $ 87,756 $ 53,910  
Amortization of deferred debt discounts and issuance costs               $ 3,740 1,271  
Warrants to purchase common stock           1,524,573   1,524,573    
Warrants maturity period         10 years     4 years    
Fair market value of warrants                   $ 7,114
Initial Public Offering [Member]                    
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Warrants to purchase common stock 809,400   809,400              
Warrants maturity period 5 years   5 years              
Percentage of warrant exercise 10.00%   10.00%              
Acacia [Member] | Initial Public Offering [Member]                    
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Warrants to purchase common stock 809,400 809,400                
Warrants maturity period 5 years 5 years                
Percentage of warrant exercise 10.00% 10.00%                
Fair market value of warrants $ 5,790 $ 5,790                
Convertible Notes Payable [Member]                    
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Amortization of deferred debt discounts and issuance costs           $ 0 3,740 $ 1,271 1,271  
Convertible Notes Payable [Member] | Initial Public Offering [Member]                    
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Warrants to purchase common stock 154,311   154,311              
Convertible Notes Payable [Member] | Acacia [Member]                    
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Warrants maturity period       5 years            
Billed Revenues [Member]                    
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Gross media placements           26,510 16,888 74,717 46,496  
Netted Against Billings [Member]                    
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]                    
Gross media placements           $ 23,222 $ 14,665 $ 64,791 $ 40,299