Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue
Net Revenue	$ 28,753	$ 24,143	$ 16,866	$ 26,051	$ 31,791	$ 31,274	$ 32,191	$ 27,816	$ 95,813	$ 123,072	$ 124,829
Remaining performance obligations on leases one year or less exemption									true
Broadcast Advertising Revenue, Net [Member]
Revenue
Net Revenue									$ 87,481	112,278	114,929
Digital Advertising Revenue [Member]
Revenue
Net Revenue									3,416	3,783	3,900
Other Revenue [Member]
Revenue
Net Revenue									$ 4,916	$ 7,011	$ 6,000