Quarterly report pursuant to Section 13 or 15(d)

Patents (Details)

v3.21.2
Patents (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]          
Intangible asset not yet subject to amortization $ 0.7   $ 0.7   $ 0.5
Patents [Member]          
Finite-Lived Intangible Assets [Line Items]          
Finite-Lived Intangible Assets, Gross 7.8   7.8   7.8
Finite-Lived Intangible Assets, Accumulated Amortization 6.7   6.7   $ 6.5
Patents [Member] | Research and Development Expense [Member]          
Finite-Lived Intangible Assets [Line Items]          
Amortization of Intangible Assets $ 0.1 $ 0.2 $ 0.1 $ 0.2  
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