Description of Business and Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Summary Of Business And Accounting Policies [Line Items]
Entity incorporation date	1994-07
Common stock equivalent shares excluded from computation of diluted per share amounts	1,227,000	691,000
Capitalized software development costs	$ 0	$ 0
Advertising expense	$ 388,000	$ 45,000
Office furniture and equipment [Member]
Summary Of Business And Accounting Policies [Line Items]
Leasehold improvements estimated useful life	3 years
Minimum [Member]
Summary Of Business And Accounting Policies [Line Items]
Intangible assets useful life range	1 year
Minimum [Member] | Leasehold improvements [Member]
Summary Of Business And Accounting Policies [Line Items]
Leasehold improvements estimated useful life	2 years
Maximum [Member]
Summary Of Business And Accounting Policies [Line Items]
Intangible assets useful life range	10 years
Maximum [Member] | Leasehold improvements [Member]
Summary Of Business And Accounting Policies [Line Items]
Leasehold improvements estimated useful life	10 years