Revenues - Summary of Revenues Disaggregated by Major Source (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Total revenue	$ 45,116	$ 69,241	$ 109,365	$ 133,921
Broadcast Advertising
Disaggregation Of Revenue [Line Items]
Total revenue	22,589	37,237	61,317	71,945
Digital Advertising
Disaggregation Of Revenue [Line Items]
Total revenue	11,373	16,804	24,704	31,276
Spectrum Usage Rights
Disaggregation Of Revenue [Line Items]
Total revenue	1,356	3,952	2,712	9,036
Retransmission Consent
Disaggregation Of Revenue [Line Items]
Total revenue	9,362	9,086	18,942	17,846
Other
Disaggregation Of Revenue [Line Items]
Total revenue	$ 436	$ 2,162	$ 1,690	$ 3,818