Revenue from Contracts with Customers - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
		Jan. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect of accounting change	[1]	$ 7,501
Deferred contract costs			$ 3,146
Deferred revenue			(3,383)		$ (3,765)	$ 3,581
Deferred income taxes			$ 531		493	$ 130
Payment period			30 days
Contract period			12 months
Revenue			$ 130,000	$ 103,520
Deferred revenue			21,000	$ 24,205	$ 24,205		$ 22,400
Capitalized contract cost, net			$ 18,414				$ 15,209
Capitalized contract cost, amortization period				5 years	5 years
Marketplaces and Digital Marketing
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract period			1 year
Accumulated Deficit
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect of accounting change	[1]	7,501
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred contract costs		8,700
Deferred revenue		(600)
Deferred income taxes		(600)
Accounting Standards Update 2014-09 | Accumulated Deficit
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect of accounting change		$ 7,500
Prepaid Expenses and Other Current Assets
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Capitalized contract cost, net			$ 5,600

[1] Refer to Note 7, "Revenue from Contracts with Customers," for additional information regarding the effect of the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606), or ASC 606, and adjustments to accumulated deficit upon adoption.