Goodwill and Other Intangible Assets - Composition of Company's Acquired Intangible Assets and Associated Accumulated Amortization (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Intangible Assets [Line Items]
Gross Carrying Amount	$ 94,890	$ 94,890
Accumulated Amortization	81,770	78,234
Net Carrying Amount	13,120	16,656
Intangible assets not subject to amortization:
Total intangible assets	233,821	237,357
FCC
Intangible assets not subject to amortization:
Licenses	$ 220,701	220,701
Television network affiliation agreements
Schedule Of Intangible Assets [Line Items]
Weighted average remaining life in years	5 years
Gross Carrying Amount	$ 65,089	65,089
Accumulated Amortization	53,492	51,172
Net Carrying Amount	$ 11,597	13,917
Customer base
Schedule Of Intangible Assets [Line Items]
Weighted average remaining life in years	1 year
Gross Carrying Amount	$ 3,146	3,146
Accumulated Amortization	2,664	1,789
Net Carrying Amount	$ 482	1,357
Other
Schedule Of Intangible Assets [Line Items]
Weighted average remaining life in years	14 years
Gross Carrying Amount	$ 26,655	26,655
Accumulated Amortization	25,614	25,273
Net Carrying Amount	$ 1,041	$ 1,382