Commitments and Contingencies - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Feb. 29, 2016	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Loss Contingencies [Line Items]
Unconditional purchase commitment aggregate amount	$ 1,062,500	$ 278,000
Unconditional purchase commitment payment terms		Quarterly
Unconditional purchase commitment period		May 31, 2020
Total expense for sales tax and maintenance obligations		$ 24,000	$ 29,000
Total payments for future sales tax and maintenance obligations		311,783
Accrued Other Liabilities [Member]
Loss Contingencies [Line Items]
Sales tax and maintenance obligations incurred but not paid		$ 78,000		$ 69,000
Minimum [Member]
Loss Contingencies [Line Items]
Unconditional purchase commitment, quarterly payment amount	$ 62,500