The Company and Significant Accounting Policies - Carrying Amount of Goodwill (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, Beginning balance		$ 74,292,000
Currency		(67,000)
Impairment		(27,714,000)	$ 0
Goodwill, Ending balance	$ 46,511,000	46,511,000	74,292,000
Television
Goodwill [Line Items]
Goodwill, Beginning balance		40,549,000
Goodwill, Ending balance	40,549,000	40,549,000	40,549,000
Digital
Goodwill [Line Items]
Goodwill, Beginning balance		33,743,000
Currency		(67,000)
Impairment	(5,300,000)	(27,714,000)
Goodwill, Ending balance	$ 5,962,000	$ 5,962,000	$ 33,743,000