Goodwill and Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 13,886	$ 10,920
Accumulated Amortization	(10,517)	(10,210)
Total intangible assets	$ 3,369	710
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	3 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	17 years
Customer, Affiliate and Advertiser Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 8,717	6,520
Accumulated Amortization	(6,419)	(6,290)
Total intangible assets	$ 2,298	$ 230
Customer, Affiliate and Advertiser Relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	5 years	5 years
Customer, Affiliate and Advertiser Relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	17 years	17 years
Developed Websites, Technology and Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	10 years	10 years
Gross Carrying Amount	$ 2,061	$ 1,476
Accumulated Amortization	(1,157)	(1,026)
Total intangible assets	904	450
Trademarks, Trade Name and Domain Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,821	1,792
Accumulated Amortization	(1,783)	(1,763)
Total intangible assets	$ 38	$ 29
Trademarks, Trade Name and Domain Name [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	5 years	5 years
Trademarks, Trade Name and Domain Name [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	8 years	8 years
Proprietary User Information Database and Internet Traffic [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	5 years	5 years
Gross Carrying Amount	$ 1,117	$ 1,122
Accumulated Amortization	$ (1,117)	$ (1,122)
Non-Compete Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	3 years	1 year 6 months
Gross Carrying Amount	$ 170	$ 10
Accumulated Amortization	(41)	(9)
Total intangible assets	$ 129	$ 1