Goodwill, Other Intangible Assets and Intangible Liabilities - Narrative (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 27, 2013 USD ($)	Dec. 31, 2012 USD ($)
Finite-Lived Intangible Assets [Line Items]
Contract intangible liability, net						$ 227,000,000
Amortizable Intangible Assets, weighted average remaining useful life		7 years
Amortization expense of amortizable intangible assets, excluding lease contract intangible assets, Next Twelve Months		$ 140,000,000
Amortization expense of amortizable intangible assets, excluding lease contract intangible assets, 2020		134,000,000
Amortization expense of amortizable intangible assets, excluding lease contract intangible assets, 2021		103,000,000
Amortization expense of amortizable intangible assets, excluding lease contract intangible assets, 2022		84,000,000
Amortization expense of amortizable intangible assets, excluding lease contract intangible assets, 2023		57,000,000
Goodwill, Impairment Loss		0	$ 0	$ 0
Goodwill		3,228,601,000	3,228,988,000	3,227,930,000
Impairment charge. FCC licenses		(3,100,000)	0	(3,400,000)
Proceeds from FCC spectrum auction		0	172,102,000	0
FCC licenses
Finite-Lived Intangible Assets [Line Items]
Impairment charge. FCC licenses		$ (3,100,000)	0	$ (3,400,000)
Fair value inputs, average revenue share period (years)		4 years
FCC License Impairments, number of licenses impaired		1		2
Gain (Loss) on Disposition of Intangible Assets	$ 133,000,000
Measurement Input, Discount Rate | Level 3 | FCC licenses
Finite-Lived Intangible Assets [Line Items]
Fair Value Measurements, Valuation Processes, Description		0.09
Measurement Input, Long-term Revenue Growth Rate | Level 3 | FCC licenses
Finite-Lived Intangible Assets [Line Items]
Fair Value Measurements, Valuation Processes, Description		0.02
Television
Finite-Lived Intangible Assets [Line Items]
Goodwill, Impairment Loss		$ 0	0
Goodwill		$ 2,505,000,000	2,506,000,000
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount		16.00%
Cable
Finite-Lived Intangible Assets [Line Items]
Goodwill, Impairment Loss		$ 0	0
Goodwill		$ 723,000,000	723,000,000
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount				23.00%
Television and Entertainment
Finite-Lived Intangible Assets [Line Items]
Contract intangible liability, net			$ 0
Amortization				$ (12,000,000)
Balance sheet reclassifications				(2,000,000)
Local TV
Finite-Lived Intangible Assets [Line Items]
Broadcast rights intangible liabilities					$ 9,000,000
Broadcast rights intangible liabilities
Finite-Lived Intangible Assets [Line Items]
Contract intangible liability, net						$ 226,000,000
Broadcast rights intangible liabilities | Television and Entertainment
Finite-Lived Intangible Assets [Line Items]
Contract intangible liability, net				$ 0