Annual report pursuant to Section 13 and 15(d)

Recent Transactions - Pending Transactions -Additional Information (Detail)

v3.20.1
Recent Transactions - Pending Transactions -Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Nov. 14, 2019
Oct. 31, 2019
Sep. 27, 2019
Sep. 26, 2019
Jun. 28, 2019
Dec. 31, 2019
Sep. 30, 2019
Dec. 31, 2019
Dec. 31, 2018
Jan. 03, 2017
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Business combination, liabilities arising from contingencies, amount recognized                   $ 500
Agreement to sell business               $ 20,741 $ 9,894  
Additional Term Of Time Brokerage Agreement         24 months          
Radio Stations [Member]                    
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                    
Agreement to sell business $ 8,700 $ 200   $ 8,200            
Pretax loss on sale of assets     $ (1,300) $ (4,700)   $ (1,500) $ (9,900)