Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Oct. 31, 2020	Oct. 31, 2018	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Nature Of Operations [Line Items]
Percentage of revenue transacted in foreign currency			9.00%		3.00%
Percentage of expenses transacted in foreign currency			21.00%		17.00%
Net foreign exchange gains (losses) resulting from foreign currency transactions included in other income			$ (100,000)		$ (300,000)
Cash and cash equivalents maturities			90 days	90 days
Investment of cash equivalents are redeemable upon demand using amortized cost method			$ 1.00
Investment in money market funds restricted by investment in short term securities, percentage			100.00%
Cash and cash equivalents in foreign bank			$ 3,900,000	$ 2,900,000
Short-term investments, maturities, minimum			90 days
Short-term investments, maturities, maximum			1 year
Long-term investments, maturities, minimum			1 year
Long-term investments, maturities, maximum			2 years
Net unrealized losses			$ 1,000	8,000
Credit loss provision			26,000	66,000
Consigned inventory with customers			400,000	300,000
Allowance for inventory losses			4,100,000	3,700,000
Depreciation and amortization			3,000,000.0	3,000,000.0
Advertising expense			$ 300,000	200,000
Most likely than not benefit likelihood percentage being realized upon ultimate settlement with taxing authority resulting from sustainability of tax examination			50.00%
Deferred tax asset, valuation allowance			$ 15,258,000	12,938,000
Deferred payroll taxes			200,000	500,000
Impairment of long-lived assets			$ 0	$ 0
Test & Measurement Product Line [Member]
Nature Of Operations [Line Items]
Goodwill impairment test			October 31, 2021
Goodwill acquired	$ 6,300,000
Test & Measurement Product Line [Member] | Product [Member]
Nature Of Operations [Line Items]
Goodwill impairment test				October 31, 2020
Goodwill acquired		$ 3,300,000
Equipment [Member]
Nature Of Operations [Line Items]
Period over which assets are depreciated			5 years
Furniture and Fixtures [Member]
Nature Of Operations [Line Items]
Period over which assets are depreciated			7 years
Building [Member]
Nature Of Operations [Line Items]
Period over which assets are depreciated			30 years
Level 3 [Member]
Nature Of Operations [Line Items]
Investments			$ 0	$ 0
CHINA [Member] | Cash Equivalents [Member]
Nature Of Operations [Line Items]
Cash and cash equivalents in foreign bank			2,800,000	$ 2,900,000
Sweden [Member] | Cash [Member]
Nature Of Operations [Line Items]
Cash and cash equivalents in foreign bank			1,000,000.0
France [Member] | Cash [Member]
Nature Of Operations [Line Items]
Cash and cash equivalents in foreign bank			100,000
Maximum [Member]
Nature Of Operations [Line Items]
Federal Deposit Insurance Corporation insured limit			$ 250,000
Standard term of accounts receivable			90 days
Useful lives of the assets			1 year
Maximum [Member] | Computer Equipment and Software License [Member]
Nature Of Operations [Line Items]
Period over which assets are depreciated			5 years
Minimum [Member]
Nature Of Operations [Line Items]
Standard term of accounts receivable			30 days
Minimum [Member] | Computer Equipment and Software License [Member]
Nature Of Operations [Line Items]
Period over which assets are depreciated			3 years