Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Deficit) - Additional Information (Detail)

v3.20.1
Stockholders' Equity (Deficit) - Additional Information (Detail) - USD ($)
 1 Months Ended 12 Months Ended
Jun. 25, 2018
Jun. 30, 2018
Apr. 30, 2018
Dec. 31, 2019
Dec. 31, 2018
Class of Stock [Line Items]          
Common stock shares issued 1,955,000        
Share price $ 18.00        
Net proceeds from stock issuance $ 32,780,000     $ 23,851,000 $ 32,770,000
Stock issuance costs $ 2,300,000        
Warrants outstanding       1,297,151 1,297,151
April 2018 Warrant [Member]          
Class of Stock [Line Items]          
Warrants outstanding     20,000    
Warrants maturity period     5 years 5 years 5 years
April 2018 Warrant [Member] | Maximum [Member]          
Class of Stock [Line Items]          
Maximum Shares to be issued for warrants     20,000    
Westwood One [Member] | Maximum [Member]          
Class of Stock [Line Items]          
Number of shares may be issued for conversion of cancelled warrants   247,422      
Common Stock and Employee Stock Purchase Plan [Member]          
Class of Stock [Line Items]          
Shares issued in connection with stock option exercise       235,808 276,561
Number of shares cancelled in connection with forfeiture of restricted stock       2,121 4,184
JMP Securities [Member]          
Class of Stock [Line Items]          
Net proceeds from stock issuance       $ 24,373,000  
Maximum aggregate sales price of shares to be issued under sale agreement.       $ 50,000,000  
Common Stock [Member]          
Class of Stock [Line Items]          
Common stock shares issued       5,205,430 1,955,000
Shares issued to outside service provider, shares         7,412
Common Stock [Member] | General and Administrative Expenses [Member]          
Class of Stock [Line Items]          
Stock-based compensation expense         $ 130,000
Common Stock [Member] | Performance Bridge, Wazee Digital and Machine Box [Member]          
Class of Stock [Line Items]          
Business acquisition, shares issued or issuable       896,400 941,548
Common Stock [Member] | JMP Securities [Member]          
Class of Stock [Line Items]          
Common stock shares issued       5,205,430  
Stock issuance costs       $ 756,000