Risk Management, Derivative Instruments and Hedging Activities - Schedule of Net Notional Volumes of Open Commodity Derivatives and Interest Rate Derivatives (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) MMBTU MWh T	Dec. 31, 2023 USD ($) MWh MMBTU T
Commodity derivatives | Short
Derivative [Line Items]
Commodity purchase (sales) derivatives, power and natural gas | MWh	(32,222,671)	(27,557,871)
Commodity derivatives | Long
Derivative [Line Items]
Commodity purchase (sales) derivatives, power and natural gas | MMBTU	(37,757,360)	(8,314,060)
Commodity purchase (sales) derivatives, emission allowances | T	346,000	500,000
Interest rate derivatives
Derivative [Line Items]
Interest rate (in millions) | $	$ 290	$ 290