Annual report pursuant to Section 13 and 15(d)

Intangible Assets and Related Accumulated Amortization (Detail)

v3.21.1
Intangible Assets and Related Accumulated Amortization (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Intangible Assets And Goodwill [Line Items]    
Intangible assets, gross $ 2,800  
Intangible assets, accumulated amortization $ (2,800)  
Useful life indefinite life  
Goodwill gross $ 2,926  
Goodwill 2,926 $ 2,926
Patents    
Intangible Assets And Goodwill [Line Items]    
Intangible assets, gross 1,914  
Intangible assets, accumulated amortization $ (1,914)  
Patents | Minimum    
Intangible Assets And Goodwill [Line Items]    
Useful life 4 years  
Patents | Maximum    
Intangible Assets And Goodwill [Line Items]    
Useful life 10 years  
Trademarks    
Intangible Assets And Goodwill [Line Items]    
Useful life 6 years  
Intangible assets, gross $ 69  
Intangible assets, accumulated amortization (69)  
Other Intangible Assets    
Intangible Assets And Goodwill [Line Items]    
Intangible assets, gross 817  
Intangible assets, accumulated amortization $ (817)  
Other Intangible Assets | Minimum    
Intangible Assets And Goodwill [Line Items]    
Useful life 4 years  
Other Intangible Assets | Maximum    
Intangible Assets And Goodwill [Line Items]    
Useful life 6 years