Subsequent Events - Additional Information (Detail) - USD ($)				12 Months Ended
	Feb. 06, 2019	Jan. 02, 2019	Feb. 08, 2017	Dec. 31, 2018	Dec. 31, 2019
Revolving Loan Facility | Loan and Security Agreements | Prime Rate
Subsequent Event [Line Items]
Percentage of interest rate			1.00%
Loan facility payable date				Feb. 08, 2019
Revolving Loan Facility | Loan and Security Agreements | East West Bank
Subsequent Event [Line Items]
Borrowing capacity under credit facility			$ 16,000,000
Subsequent Event | Revolving Loan Facility | Loan and Security Agreements
Subsequent Event [Line Items]
Loan facility payable date	Feb. 08, 2021
Subsequent Event | Revolving Loan Facility | Loan and Security Agreements | Prime Rate
Subsequent Event [Line Items]
Percentage of interest rate	0.75%
Subsequent Event | Revolving Loan Facility | Loan and Security Agreements | East West Bank
Subsequent Event [Line Items]
Borrowing capacity under credit facility	$ 20,000,000
Viscount Systems, Inc. | Maximum | Scenario, Forecast
Subsequent Event [Line Items]
Amount of earn-out consideration of payable in shares of common stock					$ 3,500,000
Amount of additional earn-out consideration of payable in shares of common stock					$ 2,250,000
Viscount Systems, Inc. | Subsequent Event
Subsequent Event [Line Items]
Date of acquisition completed		Jan. 02, 2019
Business combination, aggregate consideration		$ 3,200,000
Business combination, net of cash acquired		1,200,000
Business combination, issuance of common stock		2,000,000
Business combination, issuance of common stock value held back		150,000
Amount of maximum earn-out consideration of payable for all periods in shares of common stock		$ 3,500,000