Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 196,385	$ 280,808	$ 570,321	$ 827,977
Asset related to unamortized portion of commission expense	6,100		6,100		$ 7,900
Advertising revenues (broadcast, digital, non-traditional revenue (NTR) and trade)
Disaggregation of Revenue [Line Items]
Revenue	192,823	276,230	560,236	813,066
Non-advertising revenues (tower rental and other)
Disaggregation of Revenue [Line Items]
Revenue	3,562	4,578	10,085	14,911
Advertising Barter Transactions
Disaggregation of Revenue [Line Items]
Revenue	7,200	9,400	22,154	33,388
Other expenses	$ 6,800	$ 9,600	$ 20,941	$ 31,614
Minimum
Disaggregation of Revenue [Line Items]
Rental agreement term	1 year		1 year
Maximum
Disaggregation of Revenue [Line Items]
Rental agreement term	5 years		5 years