Summary of Fair Values of Assets Acquired and Liabilities Assumed at Acquisition (Detail) - USD ($)	Jun. 30, 2020	Dec. 31, 2019	Jan. 02, 2019
Business Acquisition [Line Items]
Goodwill	$ 10,180,000	$ 10,238,000
Viscount Systems, Inc.
Business Acquisition [Line Items]
Accounts receivable			$ 636,000
Inventory			249,000
Prepaid expenses and other current assets			29,000
Property and equipment			190,000
Operating lease ROU assets			550,000
Finite-lived intangibles			1,670,000
Total identifiable assets acquired			3,324,000
Accounts payable			(372,000)
Operating lease liabilities			(61,000)
Accrued expenses and liabilities			(120,000)
Deferred revenue			(34,000)
Earnout consideration liability	$ (489,000)	$ (750,000)	(200,000)
Other current liabilities			(326,000)
Long-term operating lease liabilities			(489,000)
Total liabilities assumed			(1,602,000)
Net identifiable assets acquired			1,722,000
Goodwill			1,200,000
Net purchase price			2,922,000
Viscount Systems, Inc. | Trademarks
Business Acquisition [Line Items]
Finite-lived intangibles			160,000
Viscount Systems, Inc. | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangibles			710,000
Viscount Systems, Inc. | Developed Technology
Business Acquisition [Line Items]
Finite-lived intangibles			$ 800,000