Business Combinations - Additional Information (Detail) - USD ($)								9 Months Ended	12 Months Ended
	Apr. 15, 2019	Feb. 14, 2019	Jan. 25, 2019	Jan. 02, 2019	Nov. 01, 2018	May 09, 2018	Feb. 14, 2018	Sep. 30, 2019	Dec. 31, 2018	Mar. 31, 2019
Business Acquisition [Line Items]
Goodwill								$ 10,128,000	$ 9,286,000
3VR
Business Acquisition [Line Items]
Date of acquisition completed							Feb. 14, 2018	Feb. 14, 2018
Business combination, aggregate consideration							$ 5,900,000
Business combination, payment of cash							1,600,000
Business combination, issuance of notes							$ 2,000,000
Business combination, issuance of common stock, shares							609,830
Business combination, issuance of common stock							$ 2,300,000
Business combination, issuance of common stock value held back			$ 300,000
Business combination, issuance of common stock shares held back			93,406				294,927
Reduction in purchase consideration	$ 340,000					$ 660,000
Reduction in goodwill	$ 340,000					$ 660,000
Business combination, cancellation of common stock shares held back	93,406					181,319
Goodwill							$ 5,456,000
3VR | ASC 805
Business Acquisition [Line Items]
Acquisition and transactional costs								$ 39,000	548,000
3VR | Notes Payable
Business Acquisition [Line Items]
Business combination, issuance of notes							2,000,000
Debt instrument payment, principal and interest		$ 2,100,000
3VR | Maximum
Business Acquisition [Line Items]
Business combination, issuance of common stock value held back							$ 1,000,000
Thursby Software Systems
Business Acquisition [Line Items]
Date of acquisition completed					Nov. 01, 2018
Business combination, aggregate consideration					$ 3,100,000
Business combination, payment of cash					$ 600,000
Business combination, issuance of common stock, shares					426,621
Business combination, issuance of common stock					$ 2,500,000
Business combination, issuance of common stock shares held back					85,324
Goodwill					$ 3,490,000
Product revenue to be achieved to obligate earnout consideration					11,000,000
Amount of additional earnout consideration of payable in shares of common stock					2,500,000
Amount of maximum earnout consideration of payable for all periods in shares of common stock					7,500,000
Thursby Software Systems | ASC 805
Business Acquisition [Line Items]
Acquisition and transactional costs								27,000	208,000
Thursby Software Systems | Maximum
Business Acquisition [Line Items]
Business combination, issuance of common stock value held back					500,000
Product revenue to be achieved to obligate earnout consideration					15,000,000
Amount of earnout consideration of payable in shares of common stock					7,500,000
Product revenue to be achieved to obligate additional earnout consideration					15,000,000
Thursby Software Systems | Minimum
Business Acquisition [Line Items]
Product revenue to be achieved to obligate earnout consideration					8,000,000
Product revenue to be achieved to obligate additional earnout consideration					$ 15,000,000
Viscount Systems, Inc.
Business Acquisition [Line Items]
Date of acquisition completed				Jan. 02, 2019
Business combination, aggregate consideration				$ 2,900,000
Business combination, payment of cash				$ 1,300,000
Business combination, issuance of common stock, shares				419,288
Business combination, issuance of common stock				$ 1,600,000
Business combination, issuance of common stock shares held back				31,446
Goodwill				$ 1,173,000
Amount of maximum earnout consideration of payable for all periods in shares of common stock				3,500,000
Fair value of earnout consideration				200,000				375,000		$ 200,000
Viscount Systems, Inc. | ASC 805
Business Acquisition [Line Items]
Acquisition and transactional costs								27,000	$ 227,000
Viscount Systems, Inc. | Maximum
Business Acquisition [Line Items]
Amount of earnout consideration of payable in shares of common stock				3,500,000
Amount of additional earnout consideration of payable in shares of common stock				$ 2,250,000
Fair value of earnout consideration								375,000
Viscount Systems, Inc. | Minimum
Business Acquisition [Line Items]
Fair value of earnout consideration								$ 175,000