Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) Market Agreement shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares
Accounting Policies [Line Items]
Cash and cash equivalents	$ 119,162				$ 33,123				$ 119,162	$ 33,123
Restricted cash	749				734				749	734
Available for sale securities	27,988				91,662				27,988	91,662
Estimated losses for bad debts									2,500	2,300	$ 1,800
Bad debts actually charged off									1,500	2,800	1,200
Long term debt fair value	210,500				211,700				$ 210,500	211,700
Percentage of tax benefit recognized									50.00%
Advertising expense									$ 100	500	100
Net revenue	$ 171,683	$ 62,978	$ 45,116	$ 64,249	70,838	$ 68,816	$ 69,241	$ 64,680	344,026	273,575	297,815
Broadcast trade cost									$ 200	$ 500	$ 700
Shares of dilutive securities not included in computation of diluted earnings per share | shares									892,720	1,117,216	182,847
Other comprehensive income (loss), net of tax									$ (925)	$ 1,281	$ (1,352)
Broadcast Equipment
Accounting Policies [Line Items]
Net revenue									$ 200	500	700
Univision
Accounting Policies [Line Items]
Number of marketing and sales agreements | Agreement									2
Number of markets involved in sales and marketing | Market									6
Cocina Vista, LLC
Accounting Policies [Line Items]
Equity method investments					$ 2,600					$ 2,600
Equity method investment ownership percentage					49.00%					49.00%
Loss on investment										$ 2,600
Accounting Standards Update 2016-18
Accounting Policies [Line Items]
Restricted cash					$ 700					700	$ 700
Accounting Standards Update 2018-15
Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020								Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true								true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true								true
Accounting Standards Update 2018-13
Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020								Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true								true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true								true
Accounting Standards Update 2016-13 | Available-for-Sale Securities
Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020								Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true								true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true								true
Accounting Standards Update 2016-13 | Trade Accounts Receivable
Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020								Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true								true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true								true
Outside the United States
Accounting Policies [Line Items]
Cash and cash equivalents	$ 34,500				$ 5,300				$ 34,500	$ 5,300