Leases - Future Minimum Lease Payments (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Operating Leases
2025	$ 68
2026	67
2027	66
2028	61
2029	61
All years thereafter	307
Total future minimum lease payments	630
Less: imputed interest	(126)
Total	504
Operating lease liabilities (current)	118	$ 116
Operating lease liabilities held for sale (current)	2
Operating lease liabilities (noncurrent)	386	$ 429
Operating lease liabilities held for sale (noncurrent)	5
Total	511
Finance Leases
2025	1
2026	1
2027	1
2028	0
2029	0
All years thereafter	1
Total future minimum lease payments	4
Less: imputed interest	0
Total	4
Other current liabilities	1
Other noncurrent liabilities	3
Total	$ 4
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	TOTAL CURRENT LIABILITIES	TOTAL CURRENT LIABILITIES
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Liabilities, Other than Long-Term Debt, Noncurrent	Liabilities, Other than Long-Term Debt, Noncurrent
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Liabilities, Other than Long-Term Debt, Noncurrent, Other Liabilities	Liabilities, Other than Long-Term Debt, Noncurrent, Other Liabilities
Broken Bow II
Operating Leases
2025	$ 4
2026	4
2027	4
2028	4
2029	4
All years thereafter	9
Less: imputed interest	(6)
Operating lease liabilities (current)	7
CECONY
Operating Leases
2025	67
2026	67
2027	66
2028	61
2029	61
All years thereafter	307
Total future minimum lease payments	629
Less: imputed interest	(125)
Total	504
Operating lease liabilities (current)	118	$ 116
Operating lease liabilities held for sale (current)	0
Operating lease liabilities (noncurrent)	386	$ 429
Operating lease liabilities held for sale (noncurrent)	0
Total	504
Finance Leases
2025	1
2026	1
2027	1
2028	0
2029	0
All years thereafter	0
Total future minimum lease payments	3
Less: imputed interest	0
Total	3
Other current liabilities	1
Other noncurrent liabilities	2
Total	$ 3