Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Income Tax Disclosure [Line Items]
Income tax expense (benefit)	$ 7	$ 8	$ 12	$ 16
Statutory rate			21.00%	21.00%
Net deferred tax assets	15,200		$ 15,200		$ 12,900
Operating loss and credit carry forward, expiration period			The Company’s federal NOLs generated in 2018 and future periods will not expire, and the Company’s NOLs and credits generated as of December 31, 2017 have a finite life primarily based on the 20-year carry forward of federal net operating losses.
Net operating loss carry forward period			20 years
Domestic deferred tax assets ratable reversal pattern period			12 years
Gross unrecognized tax benefit	800		$ 800		800
Deferred payroll taxes	500		500
Smarteq Wireless Aktiebolag [Member]
Income Tax Disclosure [Line Items]
Net deferred tax assets	2,300		2,300
Domestic Tax Authority [Member]
Income Tax Disclosure [Line Items]
Net deferred tax assets	12,100		12,100		$ 12,100
Foreign [Member] | CHINA
Income Tax Disclosure [Line Items]
Net deferred tax assets	800		800
Foreign [Member] | Sweden
Income Tax Disclosure [Line Items]
Net deferred tax assets	$ 2,300		$ 2,300