Derivative Instruments - Volumetric Underlying Derivative Transactions (Details) - Buy MWh in Thousands, MMBTU in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022 MWh MMBTU	Dec. 31, 2021 MMBTU MWh
Gain on non-trading derivatives, net | Natural Gas
Derivatives, Fair Value [Line Items]
Net notional volume (energy measure)	3,807	3,862
Gain on non-trading derivatives, net | Electricity
Derivatives, Fair Value [Line Items]
Net notional volume (energy measure) | MWh	1,893	1,785
Gain (loss) on trading derivatives, net | Natural Gas
Derivatives, Fair Value [Line Items]
Net notional volume (energy measure)	1,437	1,536