Intangible Assets and Goodwill - Intangible Assets Subject to Amortization (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross	$ 4,083,650	$ 4,185,256
Accumulated Amortization	(1,128,566)	(925,636)
Net	$ 2,955,084	$ 3,259,620
Network affiliation agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life, in years	15 years	15 years
Gross	$ 3,118,357	$ 3,223,906
Accumulated Amortization	(827,673)	(691,640)
Net	2,290,684	2,532,266
Other definite-lived intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	965,293	961,350
Accumulated Amortization	(300,893)	(233,996)
Net	$ 664,400	$ 727,354
Other definite-lived intangible assets [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life, in years	1 year	1 year
Other definite-lived intangible assets [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful life, in years	20 years	20 years