Description of Business and Accounting Policies - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($) Deposit Segment shares	Dec. 31, 2017 USD ($) shares	Jan. 01, 2019 USD ($)
Summary Of Business And Accounting Policies [Line Items]
Entity incorporation date		1994-07
Goodwill impairment charge		$ 3,738,000
Common stock equivalent shares excluded from computation of diluted per share amounts | shares		1,714,000	1,227,000
Number of restricted cash deposits | Deposit		2
Number of deposit held as security on letter of credit | Deposit		1
Letter of credit expiration year		2020
Number of deposit held as security on corporate credit card line | Deposit		1
Number of reportable segment | Segment		3
Research and development expense		$ 8,629,000	$ 6,561,000
Net capitalized software development costs	$ 945,000	945,000	0
Advertising expense		171,000	$ 388,000
Equipment, furniture, and leasehold improvements, net [Member]
Summary Of Business And Accounting Policies [Line Items]
Net capitalized software development costs	329,000	329,000
Contract assets [Member]
Summary Of Business And Accounting Policies [Line Items]
Net capitalized software development costs	226,000	226,000
Other long-term assets, including contract assets [Member]
Summary Of Business And Accounting Policies [Line Items]
Net capitalized software development costs	390,000	$ 390,000
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
ASU 2017-04 [Member]
Summary Of Business And Accounting Policies [Line Items]
Goodwill impairment charge	$ 3,700,000
ASU 2016-02 [Member] | Subsequent Event [Member]
Summary Of Business And Accounting Policies [Line Items]
Deferred rent, de-recognized				$ (500,000)
ASU 2016-02 [Member] | Minimum [Member] | Subsequent Event [Member]
Summary Of Business And Accounting Policies [Line Items]
Net lease liabilities				1,700,000
Operating lease, right-of-use assets				1,200,000
ASU 2016-02 [Member] | Maximum [Member] | Subsequent Event [Member]
Summary Of Business And Accounting Policies [Line Items]
Net lease liabilities				1,800,000
Operating lease, right-of-use assets				$ 1,300,000