Revenues - Summary of Revenues Disaggregated by Major Source (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 178,410	$ 45,116	$ 327,290	$ 109,365
Digital Advertising
Disaggregation Of Revenue [Line Items]
Total revenue	130,223	11,373	231,705	24,704
Broadcast Advertising
Disaggregation Of Revenue [Line Items]
Total revenue	36,438	22,589	70,113	61,317
Spectrum Usage Rights
Disaggregation Of Revenue [Line Items]
Total revenue	1,109	1,356	3,953	2,712
Retransmission Consent
Disaggregation Of Revenue [Line Items]
Total revenue	9,286	9,362	18,933	18,942
Other
Disaggregation Of Revenue [Line Items]
Total revenue	$ 1,354	$ 436	$ 2,586	$ 1,690