Quarterly report pursuant to Section 13 or 15(d)

Recent Transactions - Acquisitions - Additional Information (Detail)

v3.21.2
Recent Transactions - Acquisitions - Additional Information (Detail) - USD ($)
Jul. 02, 2021
Jul. 01, 2021
Jun. 01, 2021
Apr. 28, 2021
Sep. 30, 2021
Mar. 08, 2021
Dec. 31, 2020
Dec. 31, 2019
Business Acquisition [Line Items]                
Asset Acquisition, contingent earnout consideration           $ 11,000,000    
Goodwill     $ 200,000   $ 23,986,000   $ 23,757,000 $ 23,998,000
Business combination, recognized identifiable assets acquired and liabilities assumed, contingent liability           $ 100,000    
Senior Resource.com [Member]                
Business Acquisition [Line Items]                
Payments to Acquire Productive Assets $ 100,000              
KDIA AM AND KDYA AM Sanfrancisco California [Member]                
Business Acquisition [Line Items]                
Payments to Acquire Businesses     600,000          
Goodwill     $ 4,000          
Centerline New Media Domain And Digital Assets [Member]                
Business Acquisition [Line Items]                
Payments to Acquire Businesses       $ 1,300,000        
Goodwill       $ 24,000        
Shift Worship.com [Member]                
Business Acquisition [Line Items]                
Payments to Acquire Businesses, Net of Cash Acquired   $ 2,600,000