Quarterly report pursuant to Section 13 or 15(d)

Recent Transactions - Divestitures - Additional Information (Detail)

v3.21.2
Recent Transactions - Divestitures - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 9 Months Ended
Jul. 27, 2021
Jul. 23, 2021
May 25, 2021
Mar. 18, 2021
Feb. 05, 2020
Sep. 30, 2021
Jun. 30, 2021
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Proceeds from sale of productive assets               $ 15,771 $ 188  
Gain (loss) on disposition of assets             $ 500      
Deferred income taxes     $ 400     $ 69,287   $ 69,287   $ 68,883
Local Marketing Agreement [Member]                    
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Debt Instrument, Maturity Date, Description               one year    
Hilary Kramer Financial Newsletter [Member]                    
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Proceeds from sale of property, plant, and equipment $ 200                  
Gain (Loss) on Disposition of Property Plant Equipment $ 100                  
Thirty Four Acres land [Member]                    
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Proceeds from sale of property, plant, and equipment   $ 12,100                
Gain (Loss) on Disposition of Property Plant Equipment   $ 10,500                
Radio Stations [member]                    
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Proceeds from sale of productive assets         $ 4,000     $ 3,200    
Pretax loss on sale of assets           $ 1,400   $ 400    
Radio Stations [member] | FM Translators [Member]                    
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Proceeds from sale of productive assets       $ 3,500            
Singing News Magazine And Singing News Radio [Member]                    
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Proceeds from sale of productive assets     $ 100