v3.25.4
Revenue from contracts with customers transaction prices allocated to significant unsatisfied remaining performance obligations and timing of when performance obligations expected to be satisfied (Detail)
$ in Millions
Dec. 31, 2025
USD ($)
Electricity and Natural Gas [Member]  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Transaction price allocated to remaining performance obligations $ 21,368
Electricity and Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Transaction price allocated to remaining performance obligations $ 3,261
Performance obligations expected to be satisfied, period 12 months
Electricity and Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Transaction price allocated to remaining performance obligations $ 18,107
Performance obligations expected to be satisfied, period
Other Sales and Service Contracts [Member]  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Transaction price allocated to remaining performance obligations $ 13,587
Other Sales and Service Contracts [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Transaction price allocated to remaining performance obligations $ 3,833
Performance obligations expected to be satisfied, period 12 months
Other Sales and Service Contracts [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Transaction price allocated to remaining performance obligations $ 9,754
Performance obligations expected to be satisfied, period