Revenue from Contracts with Customers - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Order shipments, description	A majority of the Company’s revenue is short cycle in nature with shipments within one year from order.
Payment terms, description	The Company's payment terms generally range between 30 to 90 days.
Period for performance obligation to provide software maintenance and support	1 year
Contract assets	$ 0	$ 0
Contract with customer liability, revenue recognized	100,000
Accrued Liabilities [Member]
Disaggregation Of Revenue [Line Items]
Refund liability	200,000	200,000
Contract liability	300,000	300,000
Inventories [Member]
Disaggregation Of Revenue [Line Items]
Product return asset	$ 100,000	$ 100,000