Annual report pursuant to Section 13 and 15(d)

Derivatives. (Details) - Schedule of derivatives not designated as hedging instruments

v3.21.1
Derivatives. (Details) - Schedule of derivatives not designated as hedging instruments - Not Designated as Hedging Instrument [Member] - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Cash collateral balance [Member]    
Derivatives. (Details) - Schedule of derivatives not designated as hedging instruments [Line Items]    
Assets, fair value $ 520 $ 615
Commodity contracts [Member]    
Derivatives. (Details) - Schedule of derivatives not designated as hedging instruments [Line Items]    
Assets, fair value 17,149 2,438
Liabilities, fair value $ 1,860