Material Contingencies - Additional Information (Details) $ in Millions		1 Months Ended	3 Months Ended
	Mar. 12, 2014 people building	Feb. 28, 2017 USD ($)	Mar. 31, 2026 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2020 USD ($)
Loss Contingencies [Line Items]
Accrued regulatory liability			$ 5,028	$ 5,374
Guarantee obligations maximum exposure			$ 59	$ 60
Payment Guarantee by CET Electric of Contributions to New York Transco LLC
Loss Contingencies [Line Items]
Estimated project cost (in percent)			175.00%
NY Transco | Payment Guarantee by CET Electric of Contributions to New York Transco LLC
Loss Contingencies [Line Items]
Ownership interest (in percent)			45.70%
Manhattan Explosion and Fire
Loss Contingencies [Line Items]
Number of Buildings Destroyed by Fire | building	2
Number of people died in explosion and fire incident | people	8
Number of people injured in explosion and fire incident (more than) | people	50
Amount of costs that will not recover from customers		$ 126
Loss contingency accrual					$ 40
Insurance receivable					$ 40
Accrued liability			$ 25
Manhattan Explosion and Fire | Settlement of Gas Proceedings
Loss Contingencies [Line Items]
Accrued regulatory liability		$ 27