Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) Market Agreement shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares
Accounting Policies [Line Items]
Cash and cash equivalents	$ 46,733				$ 39,560				$ 46,733	$ 39,560
Restricted cash	732				222,294				732	222,294
Available for sale securities	132,424								132,424
Estimated losses for bad debts									1,800	1,100	$ 800
Bad debts actually charged off									1,200	1,100	1,400
Long term debt fair value	241,300				300,000				241,300	300,000
Interest expense									$ 15,743	16,709	15,469
Percentage of tax benefit recognized									50.00%
Advertising expense									$ 100	600	400
Total net revenue	82,073	$ 74,575	$ 74,329	$ 66,838	73,460	$ 334,555	$ 70,509	$ 57,510	297,815	536,034	258,514
Broadcast trade cost									$ 700	$ 900	$ 500
Shares of dilutive securities not included in computation of diluted earnings per share | shares									182,847	243,234	698,344
Comprehensive income (loss)									$ (1,352)	$ 2,917	$ 1,138
Impairment loss on investment									$ 1,320
Federal income tax rate									21.00%	35.00%	35.00%
Provisional one-time net tax benefit due to tax act										$ 17,300
Broadcast Equipment
Accounting Policies [Line Items]
Total net revenue									$ 700	900	$ 500
Univision
Accounting Policies [Line Items]
Number of marketing and sales agreements | Agreement									2
Number of markets involved in sales and marketing | Market									6
Reclassification out of Accumulated Other Comprehensive Income
Accounting Policies [Line Items]
Interest expense										2,500
Interest Rate Swap Agreements
Accounting Policies [Line Items]
Interest rate swap agreement beginning date									Dec. 31, 2015
Interest rate swap terminated date									Nov. 28, 2017
Chanclazo Studios, Inc
Accounting Policies [Line Items]
Equity method investments	$ 1,300								$ 1,300
Equity method investment ownership percentage	18.00%								18.00%
Cocina Vista, LLC
Accounting Policies [Line Items]
Equity method investments	$ 2,300								$ 2,300
Equity method investment ownership percentage	44.10%								44.10%
Accounting Standards Update 2016-18
Accounting Policies [Line Items]
Restricted cash	$ 700				222,300				$ 700	222,300
Restricted cash used as collateral for letters of credit					800					800
Accounting Standards Update 2016-18 | FCC
Accounting Policies [Line Items]
Proceeds for broadcast spectrum										221,500
Accounting Standards Update 2016-01
Accounting Policies [Line Items]
Impairment loss on investment									1,300
Outside the United States
Accounting Policies [Line Items]
Cash and cash equivalents	$ 5,300				$ 5,800				$ 5,300	$ 5,800