The Company and Significant Accounting Policies - Carrying Amount of Goodwill (Detail) - USD ($)	3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill, Beginning balance		$ 46,511,000	$ 46,511,000
Impairment	$ 0		(800,000)
Goodwill, Ending balance	45,711,000		45,711,000	$ 46,511,000
Television
Goodwill [Line Items]
Goodwill, Beginning balance		40,549,000	40,549,000
Impairment		0
Goodwill, Ending balance	40,549,000		40,549,000	40,549,000
Radio
Goodwill [Line Items]
Goodwill, Ending balance	0		0
Digital
Goodwill [Line Items]
Goodwill, Beginning balance		5,962,000	5,962,000
Impairment		$ (800,000)	(800,000)	(27,700,000)
Goodwill, Ending balance	$ 5,162,000		$ 5,162,000	$ 5,962,000