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, 2019	Dec. 31, 2018
Schedule Of Intangible Assets [Line Items]
Gross Carrying Amount	$ 116,591	$ 116,391
Accumulated Amortization	99,819	93,793
Net Carrying Amount	16,772	22,598
Intangible assets not subject to amortization:
Total intangible assets	269,316	277,196
FCC Licenses and Spectrum Usage Rights
Intangible assets not subject to amortization:
Licenses	$ 252,544	254,598
Television network affiliation agreements
Schedule Of Intangible Assets [Line Items]
Weighted average remaining life in years	7 years
Gross Carrying Amount	$ 67,489	67,489
Accumulated Amortization	58,338	56,950
Net Carrying Amount	$ 9,151	10,539
Customer base
Schedule Of Intangible Assets [Line Items]
Weighted average remaining life in years	4 years
Gross Carrying Amount	$ 10,045	10,045
Accumulated Amortization	6,414	5,044
Net Carrying Amount	$ 3,631	5,001
Pre-sold advertising contracts and other
Schedule Of Intangible Assets [Line Items]
Weighted average remaining life in years	5 years
Gross Carrying Amount	$ 39,057	38,857
Accumulated Amortization	35,067	31,799
Net Carrying Amount	$ 3,990	$ 7,058