Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v3.22.2.2
Fair Value Measurements (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2022
Jun. 30, 2021
Jun. 30, 2022
Jun. 30, 2021
Fair Value Measurements (Details) [Line Items]        
Power curtailment credits   $ 1.1   $ 1.1
Fair value of derivative asset $ 0.2     $ 0.2
Discount Rate [Member]        
Fair Value Measurements (Details) [Line Items]        
Discount rate     21.00%  
Level 3 [Member]        
Fair Value Measurements (Details) [Line Items]        
Changes in fair value 60.9   $ 104.6  
Level 3 [Member] | Demand Response Programs [Member]        
Fair Value Measurements (Details) [Line Items]        
Change in fair value of derivative asset $ 5.7   $ 8.3  
Whinstone [Member] | Discount Rate [Member]        
Fair Value Measurements (Details) [Line Items]        
Discount rate     21.00%  
Whinstone [Member] | Standard & Poor's [Member]        
Fair Value Measurements (Details) [Line Items]        
Discount rate     2.50%