Revenues - Summary of Disaggregation of Broadcast Advertising Revenue by Sales Channel (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Total revenue	$ 241,014	$ 199,008	$ 659,881	$ 526,298
Advertising
Disaggregation Of Revenue [Line Items]
Total revenue	39,965	40,495	106,769	110,608
Advertising | Local Direct
Disaggregation Of Revenue [Line Items]
Total revenue	5,935	5,881	17,365	16,850
Advertising | Local Agency
Disaggregation Of Revenue [Line Items]
Total revenue	13,410	16,122	38,980	44,529
Advertising | National Agency
Disaggregation Of Revenue [Line Items]
Total revenue	$ 20,620	$ 18,492	$ 50,424	$ 49,229