Commitments and Contingencies, Leases (Details) - USD ($)		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Maximum Length - Short-Term Leases		12 months
Operating Lease, Weighted Average Discount Rate, Percent		4.20%
Operating Lease, Assets and Liabilities, Lessee [Abstract]
Operating Lease, Right-of-Use Asset, Gross		$ 735,000,000	$ 692,000,000
Operating Lease, Right-of-Use Asset, Accumulated Depreciation		(369,000,000)	(255,000,000)
Operating lease right-of-use assets		366,000,000	437,000,000
Finance Lease, Assets and Liabilities, Lessee [Abstract]
Finance Lease, Right-of-Use Asset, Gross		181,000,000	181,000,000
Finance Lease, Right-of-Use Asset, Accumulated Depreciation		$ (67,000,000)	$ (64,000,000)
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]		Assets	Assets
Finance Lease, Right-of-Use Asset		$ 114,000,000	$ 117,000,000
Lease, Cost [Abstract]
Operating Lease, Cost	[1]	108,000,000	111,000,000	$ 118,000,000
Finance Lease, Right-of-Use Asset, Amortization		3,000,000	4,000,000	7,000,000
Finance Lease, Interest Expense		15,000,000	16,000,000	17,000,000
Finance Lease, Cost		18,000,000	20,000,000	24,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Lessee, Operating Lease, Liability, to be Paid, Year One		117,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Two		109,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Three		82,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Four		52,000,000
2028		28,000,000
Thereafter		45,000,000
Total minimum obligation		433,000,000
Interest component of obligation		(41,000,000)
Operating lease liabilities		392,000,000
Less current portion		(102,000,000)	(80,000,000)
Operating lease liabilities		290,000,000	$ 379,000,000
Weighted Average Remaining lease term, operating		4.6
Weighted Average Remaining lease term, finance		36.8
Lessee, Finance Lease, Description [Abstract]
2024		18,000,000
2025		18,000,000
2026		18,000,000
2027		16,000,000
2028		15,000,000
Thereafter		333,000,000
Total minimum obligation		418,000,000
Interest component of obligation		(304,000,000)
Present value of minimum obligation		114,000,000
Less current portion		(3,000,000)
Noncurrent operating and finance lease liabilities		$ 111,000,000
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Current	Other Liabilities, Current
WYCO, Inc. [Member]
Lessee, Finance Lease, Description [Abstract]
Equity Method Investment, Ownership Percentage		50.00%
Property, Plant and Equipment, Other Types [Member]
Operating Lease, Assets and Liabilities, Lessee [Abstract]
Operating Lease, Right-of-Use Asset, Gross		$ 112,000,000	$ 80,000,000
Lease, Cost [Abstract]
Operating Lease, Cost	[2]	19,000,000	20,000,000	16,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Lessee, Operating Lease, Liability, to be Paid, Year One		19,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Two		12,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Three		8,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Four		8,000,000
2028		8,000,000
Thereafter		6,000,000
Total minimum obligation		61,000,000
Interest component of obligation		(6,000,000)
Operating lease liabilities		55,000,000
Gas Storage Facilities [Member]
Finance Lease, Assets and Liabilities, Lessee [Abstract]
Finance Lease, Right-of-Use Asset, Gross		160,000,000	160,000,000
Gas Pipeline
Finance Lease, Assets and Liabilities, Lessee [Abstract]
Finance Lease, Right-of-Use Asset, Gross		21,000,000	21,000,000
Purchased Power Agreements
Operating Lease, Assets and Liabilities, Lessee [Abstract]
Operating Lease, Right-of-Use Asset, Gross		623,000,000	612,000,000
Lease, Cost [Abstract]
Operating Lease, Cost		89,000,000	$ 91,000,000	$ 102,000,000
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Lessee, Operating Lease, Liability, to be Paid, Year One	[3],[4]	98,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Two	[3],[4]	97,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Three	[3],[4]	74,000,000
Lessee, Operating Lease, Liability, to be Paid, Year Four	[3],[4]	44,000,000
2028	[3],[4]	20,000,000
Thereafter	[3],[4]	39,000,000
Total minimum obligation	[3],[4]	372,000,000
Interest component of obligation	[3],[4]	(35,000,000)
Operating lease liabilities	[3],[4]	$ 337,000,000

[1] PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power.

[2] Includes immaterial short-term lease expense of for 2023, 2022 and 2021.

[3] Amounts do not include PPAs accounted for as executory contracts and/or contingent payments, such as energy payments on renewable PPAs.

[4] PPA operating leases contractually expire at various dates through 2032.