Accounting for Derivative Instruments and Hedging Activities (Offsetting) (Details) - Commodity Contract [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Derivative Asset, Fair Value, Amount Offset Against Collateral [Abstract]
Derivative Asset, Fair Value, Gross Asset	$ 154,407	$ 41,820
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	154,407	41,820
Derivative, Collateral, Obligation to Return Securities	40,833	21,696
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	113,574	20,124
Derivative Liability, Fair Value, Amount Offset Against Collateral [Abstract]
Derivative Liability, Fair Value, Gross Liability	104,274	61,274
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	104,274	61,274
Derivative, Collateral, Right to Reclaim Securities	40,833	21,696
Derivative, Collateral, Right to Reclaim Cash	1,743	9,343
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 61,698	$ 30,235