Goodwill And Other Intangible Assets - (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Indefinite-lived Intangible Assets [Line Items]
Other intangible assets not subject to amortization	$ 755,100	$ 794,000
Total other intangible assets, net (excluding goodwill)	1,655,467	1,819,134
Goodwill	3,228,869	3,227,930
Total goodwill and other intangible assets	4,884,336	5,047,064
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross	1,588,624	1,587,548
Intangible assets, accumulated amortization	(688,257)	(562,414)
Intangible assets subject to amortization, net	900,367	1,025,134
FCC Licenses
Indefinite-lived Intangible Assets [Line Items]
Other intangible assets not subject to amortization	740,300	779,200
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	(62,938)	(53,000)
Intangible assets subject to amortization, net	$ 149,062	159,000
Affiliate Relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	16 years
Affiliate Relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
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	(99,750)	(84,000)
Intangible assets subject to amortization, net	$ 68,250	84,000
Advertiser relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	8 years
Advertiser relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
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	(164,934)	(133,725)
Intangible assets subject to amortization, net	$ 197,066	228,275
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	(354,524)	(286,994)
Intangible assets subject to amortization, net	$ 475,576	543,106
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	$ 16,524	15,448
Intangible assets, accumulated amortization	(6,111)	(4,695)
Intangible assets subject to amortization, net	$ 10,413	$ 10,753
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