The Company and Significant Accounting Policies - Additional Information (Detail)			3 Months Ended				9 Months Ended		12 Months Ended
	Jun. 04, 2021 USD ($)	Nov. 30, 2017 USD ($)	Sep. 30, 2022 USD ($) Country Unit Market Advertiser AdvertisingCustomer shares	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2021 USD ($) shares	Sep. 30, 2022 USD ($) Country Unit Market Segment Advertiser AdvertisingCustomer Station $ / shares shares	Sep. 30, 2021 USD ($) shares	Dec. 31, 2021 USD ($) Advertiser	Mar. 01, 2022 USD ($)	Nov. 01, 2021	Sep. 01, 2021	Jul. 01, 2021	Oct. 13, 2020
Accounting Policies [Line Items]
Number of reportable segments | Segment							3
Number of business units | Unit			4				4
Percentage of defer the employer portion of social security payroll tax of CARES act							6.20%
Percentage of deferred employer portion of social security payroll tax of CARES act									50.00%
Percentage of deferred amount of social security payroll tax of CARES act									50.00%
Restricted cash			$ 751,000			$ 749,000	$ 751,000	$ 749,000	$ 749,000
Amount due from television stations for carriage			3,800,000				3,800,000
Retransmission consent revenue			8,900,000			9,100,000	$ 27,200,000	$ 28,100,000
Number of Class A common stock shares converted | shares							1
Share-based compensation expenses			$ 2,800,000			$ 1,100,000
Shares of dilutive securities not included in computation of diluted earnings per share | shares			4,052			327	34,388	337
Amount approved under share purchase										$ 20,000,000
Aggregate purchase price of repurchased shares				$ 4,138,000	$ 7,142,000
Unamortized debt issuance costs			$ 1,377,000				$ 1,377,000		$ 1,851,000
Number of advertisers represent more than five percent of trade receivables | Advertiser			0				0
Number of advertising customer represented more than five percent of revenue | AdvertisingCustomer			0				0
Estimated losses for bad debts			$ 1,200,000			$ 900,000	$ 2,200,000	$ 3,200,000
Bad debts actually charged off			1,300,000			200,000	1,800,000	700,000
Interest income related to available-for-sale securities			$ 788,000			$ 12,000	$ 1,916,000	$ 235,000
Customer Concentration Risk | Revenue | Commercial Partner
Accounting Policies [Line Items]
Concentration risk percentage			49.00%			54.00%	51.00%	56.00%
Largest Advertisers | Customer Concentration Risk | Trade Receivables
Accounting Policies [Line Items]
Number of largest advertisers | Advertiser			5				5		5
Concentration risk percentage							4.00%		3.00%
Largest Advertisers | Customer Concentration Risk | Revenue
Accounting Policies [Line Items]
Concentration risk percentage			11.00%			11.00%	13.00%	11.00%
Cisneros Interactive
Accounting Policies [Line Items]
Remaining ownership interest acquired			49.00%				49.00%					49.00%
Ownership interest acquired												100.00%		51.00%
MediaDonuts
Accounting Policies [Line Items]
Ownership interest acquired			100.00%				100.00%						100.00%
365 Digital
Accounting Policies [Line Items]
Ownership interest acquired			100.00%				100.00%				100.00%
Available-for-Sale Securities
Accounting Policies [Line Items]
Interest income related to available-for-sale securities			$ 600,000			$ 0.0	$ 1,700,000	$ 200,000
2017 Credit Facility
Accounting Policies [Line Items]
Agreement date		Nov. 30, 2017
Additional borrowing capacity		$ 100,000,000.0
First lien net leverage ratio		4.00%
Certain customary events of default, number of business days to default in the payment of interest on borrowings							3 days
Certain customary events of default, number of days default continue for compliance with other agreement							30 days
Certain customary events of default, number of days default continue for financial statement delivery obligations							10 days
Certain customary events of default, indebtedness aggregate amount							$ 15,000,000.0
Certain customary events of default, failure in payment of final judgments aggregate amount							$ 15,000,000.0
Certain customary events of default, failure in payment of final judgments aggregate amount period							30 days
Leverage ratio			1.4			1.6	1.4	1.6
Percentage of fee equal to amount of outstanding loans	0.375%
Fee amount	$ 600,000
2017 Credit Facility | Eurodollar Rate
Accounting Policies [Line Items]
Variable interest rate basis spread on debt		2.75%
2017 Credit Facility | Base Rate Margin
Accounting Policies [Line Items]
Variable interest rate basis spread on debt		1.75%
2017 Credit Facility | Term Loan B Facility
Accounting Policies [Line Items]
Senior Secured debt		$ 300,000,000.0
Interest rate							5.27%
Maturity date of revolving credit facility		Nov. 30, 2024
Carrying value of term loan			$ 208,600,000				$ 208,600,000
Unamortized debt issuance costs			1,400,000				1,400,000
Estimated fair value of term loan			$ 205,300,000				$ 205,300,000
Class A common stock
Accounting Policies [Line Items]
Number of shares repurchased | shares			0				1,800,000
Aggregate purchase price of repurchased shares							$ 11,300,000
Average price of repurchased shares | $ / shares							$ 6.43
Stock Options And Restricted Stock Units
Accounting Policies [Line Items]
Share-based compensation expenses							$ 8,000,000.0	$ 3,300,000
Employee Stock Options
Accounting Policies [Line Items]
Share-based compensation expenses			$ 0			$ 0	0	0
Restricted Stock Units
Accounting Policies [Line Items]
Total unrecognized compensation expense related to grants of restricted stock units			8,100,000				$ 8,100,000
Weighted average period for unrecognized compensation expense related to grants of restricted stock units							1 year 4 months 24 days
TelevisaUnivision
Accounting Policies [Line Items]
Payment of sales representation fees to television stations			2,000,000.0			2,100,000	$ 5,400,000	6,000,000.0
Number of markets involved in sales and marketing | Market							3
Retransmission consent revenue			$ 6,200,000			$ 6,400,000	$ 18,700,000	$ 19,700,000
Common stock percentage held by Univision			11.00%				11.00%
UniMas
Accounting Policies [Line Items]
Affiliate advertising minutes per hour for which entity has right to sell							4 minutes 30 seconds
Minimum
Accounting Policies [Line Items]
Sales Operations in Number of Countries | Country			30				30
Minimum | Employee Stock Options
Accounting Policies [Line Items]
Vesting period							1 year
Minimum | Restricted Stock Units
Accounting Policies [Line Items]
Vesting period							1 year
Minimum | TelevisaUnivision
Accounting Policies [Line Items]
Affiliate advertising minutes per hour for which entity has right to sell							4 minutes
Maximum
Accounting Policies [Line Items]
Terminated stock repurchase program amount										$ 45,000,000
Maximum | Employee Stock Options
Accounting Policies [Line Items]
Vesting period							4 years
Maximum | Restricted Stock Units
Accounting Policies [Line Items]
Vesting period							4 years
Television
Accounting Policies [Line Items]
Number of stations owned | Station							49
Radio
Accounting Policies [Line Items]
Number of stations owned | Station							45
Number of markets operated | Market			14				14
Advertisements and Syndicate Radio Programming | Minimum
Accounting Policies [Line Items]
Number of markets owned | Market							100