Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.21.1
Subsequent Events - Additional Information (Detail)
$ in Thousands
3 Months Ended
Apr. 30, 2021
USD ($)
Apr. 28, 2021
USD ($)
Apr. 20, 2021
USD ($)
Apr. 10, 2021
USD ($)
a
Mar. 31, 2021
USD ($)
Mar. 31, 2020
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Agreement to sell business         $ 3,501 $ 2
Subsequent Event [Member] | Common Class A [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Proceeds from shelf registration supplement maximum amount $ 15,000          
Subsequent Event [Member] | Centerline new media domain and digital assets [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Payments to acquire business   $ 1,300        
Subsequent Event [Member] | Singing News Magazine and Singing News Radio [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Agreement to sell business     $ 100      
Subsequent Event [Member] | KSKY AM [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Agreement to sell business       $ 12,100    
Area of land | a       34