Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($) Customer	Dec. 31, 2018 USD ($) Customer	Dec. 31, 2017 USD ($)	Jan. 01, 2019 USD ($)	Jan. 01, 2018 USD ($)
Revenue, Major Customer [Line Items]
Operating leases right of use assets	$ 4,261,000			$ 4,329,000
Operating Lease, Liability	4,375,000			$ 4,455,000
Foreign currency gains (losses)	$ (108,000)	$ (260,000)	$ 323,000
Maturity period of cash and cash equivalents	less than three months
Available-for-sale securities, failed auction, value	$ 3,000,000
Number of customers accounted for trade account receivable | Customer	1	1
Cost of advertising	$ 2,749,000	$ 2,610,000	$ 2,150,000
Percentage likelihood of tax benefit settlement	50.00%
Retained Earnings (Accumulated Deficit)	$ 143,098,000	129,000,000
Accounting Standards Update 2014-09 [Member]
Revenue, Major Customer [Line Items]
Deferred revenue current	$ 76,000	991,000
Accounting Standards Update 2014-09 [Member] | Adjustments [Member]
Revenue, Major Customer [Line Items]
Retained Earnings (Accumulated Deficit)		$ (5,408,000)			$ 3,670,000
Customer One [Member]
Revenue, Major Customer [Line Items]
Percentage of trade account receivable	14.30%	14.30%
Maximum [Member]
Revenue, Major Customer [Line Items]
Estimated useful life of intangible assets	20 years
Customer Payments Period	60 days
Minimum [Member]
Revenue, Major Customer [Line Items]
Customer Payments Period	30 days