Goodwill And Other Intangible Assets - (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Indefinite-lived Intangible Assets [Line Items]
Other intangible assets not subject to amortization	$ 755,100	$ 755,100
Total other intangible assets, net (excluding goodwill)	1,487,534	1,613,665
Goodwill	3,228,716	3,228,988
Total goodwill and other intangible assets	4,716,250	4,842,653
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	1,588,238	1,588,750
Intangible assets, accumulated amortization	(855,804)	(730,185)
Intangible assets subject to amortization, net	732,434	858,565
FCC Licenses
Indefinite-lived Intangible Assets [Line Items]
Other intangible assets not subject to amortization	740,300	740,300
Trade Names
Indefinite-lived Intangible Assets [Line Items]
Other intangible assets not subject to amortization	14,800	14,800
Affiliate Relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	212,000	212,000
Intangible assets, accumulated amortization	(76,188)	(66,250)
Intangible assets subject to amortization, net	$ 135,812	145,750
Useful life (years)	16 years
Advertiser relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 168,000	168,000
Intangible assets, accumulated amortization	(120,750)	(105,000)
Intangible assets subject to amortization, net	$ 47,250	63,000
Useful life (years)	8 years
Network Affiliation Agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 362,000	362,000
Intangible assets, accumulated amortization	(206,546)	(175,337)
Intangible assets subject to amortization, net	$ 155,454	186,663
Network Affiliation Agreements | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	5 years
Network Affiliation Agreements | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	16 years
Retransmission Consent Agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 830,100	830,100
Intangible assets, accumulated amortization	(444,563)	(377,033)
Intangible assets subject to amortization, net	$ 385,537	453,067
Retransmission Consent Agreements | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	7 years
Retransmission Consent Agreements | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	12 years
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	$ 16,138	16,650
Intangible assets, accumulated amortization	(7,757)	(6,565)
Intangible assets subject to amortization, net	$ 8,381	$ 10,085
Other Intangible Assets | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	5 years
Other Intangible Assets | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	15 years