Income Taxes - Summary of Significant Components of Deferred Tax Assets (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Components Of Deferred Tax Assets [Abstract]
Acquired technology	$ 81,000	$ 103,000
Stock compensation expense	574,000	490,000
Accruals and other	244,000	216,000
Total deferred tax assets	899,000	809,000
Less valuation allowance	$ (899,000)	$ (809,000)