Quarterly report pursuant to Section 13 or 15(d)

Recent Transactions - Pending Transactions - Additional Information (Detail)

v3.19.3
Recent Transactions - Pending Transactions - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 27, 2019
Sep. 26, 2019
Aug. 13, 2019
Jun. 28, 2019
Jan. 03, 2017
Sep. 30, 2019
Sep. 30, 2019
Sep. 30, 2018
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]                
Agreement to sell business             $ 4,202,000 $ 8,518,000
Business combination, liabilities arising from contingencies, amount recognized         $ 500,000      
Term of time brokerage agreement         24 months      
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 $ 0 $ 8,200,000 $ 8,700,000          
Pretax loss on sale of assets $ (1,300,000) $ (4,700,000)       $ 9,900,000