Segment Data - Summary of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Net revenue	$ 1,118,203	$ 663,575	$ 3,124,658	$ 1,939,234
Broadcast [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	1,094,804	637,148	3,060,279	1,858,226
Other [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	23,399	26,427	64,379	81,008
Core Advertising (Local and National) [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	381,929	290,213	1,097,548	809,668
Core Advertising (Local and National) [Member] | Broadcast [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	381,929	290,213	1,097,509	809,668
Core Advertising (Local and National) [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Net revenue			39
Political Advertising [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	132,387	10,899	209,294	15,363
Political Advertising [Member] | Broadcast [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	132,387	10,899	209,294	15,363
Distribution [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	538,376	294,808	1,624,636	923,050
Distribution [Member] | Broadcast [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	538,271	294,808	1,622,639	923,050
Distribution [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	105		1,997
Trade [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	2,120	3,848	7,873	10,785
Trade [Member] | Broadcast [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	2,120	3,848	7,873	10,785
Digital [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	55,231	58,137	158,332	167,209
Digital [Member] | Broadcast [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	33,488	32,385	100,949	86,906
Digital [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	21,743	25,752	57,383	80,303
Other [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	8,160	5,670	26,975	13,159
Other [Member] | Broadcast [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	6,609	4,995	22,015	12,454
Other [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Net revenue	$ 1,551	$ 675	$ 4,960	$ 705