Revenue from contracts with customers transaction price allocated to significant unsatisfied remaining performance obligations and timing of when performance obligations expected to be satisfied (Detail 1) $ in Millions	Mar. 31, 2024 USD ($)
Electricity, Natural Gas and Fuel [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 22,769
Other Sales and Service Contracts [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 8,428