Quarterly report pursuant to Section 13 or 15(d)

Patents (Details)

v3.21.1
Patents (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]      
Finite-Lived Intangible Assets, Gross     $ 7.8
Finite-Lived Intangible Assets, Accumulated Amortization $ 6.6    
Intangible asset not yet subject to amortization 0.6   0.5
Patents [Member]      
Finite-Lived Intangible Assets [Line Items]      
Finite-Lived Intangible Assets, Gross 7.8    
Finite-Lived Intangible Assets, Accumulated Amortization     $ 6.5
Patents [Member] | Research and Development Expense [Member]      
Finite-Lived Intangible Assets [Line Items]      
Amortization of Intangible Assets $ 0.1 $ 0.1  
Patents [Member] | Maximum [Member]      
Finite-Lived Intangible Assets [Line Items]      
Finite-Lived Intangible Asset, Useful Life 16 years    
Patents [Member] | Minimum [Member]      
Finite-Lived Intangible Assets [Line Items]      
Finite-Lived Intangible Asset, Useful Life 13 years