Regulatory Assets and Liabilities, Regulatory Liabilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		$ 54	$ 57
Regulatory Liability, Noncurrent		709	718
Deferred Income Tax Adjustments and TCJA Refunds
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	[1]	15	6
Regulatory Liability, Noncurrent	[1]	486	513
Plant Removal Costs
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		0	0
Regulatory Liability, Noncurrent		190	177
Revenue Subject to Refund
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		6	4
Regulatory Liability, Noncurrent		$ 4	4
Revenue Subject to Refund | Minimum [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Amortization Period		1 year
Revenue Subject to Refund | Maximum [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Amortization Period		2 years
Gain From Asset Sales
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		$ 0	0
Regulatory Liability, Noncurrent		2	2
Deferred Electric Energy Costs
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		0	35
Regulatory Liability, Noncurrent		0	0
Contract Valuation Adjustments
Regulatory Liabilities [Line Items]
Regulatory Liability, Current	[2]	27	7
Regulatory Liability, Noncurrent	[2]	$ 1	0
Contract Valuation Adjustments | Minimum [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Amortization Period		1 year
Contract Valuation Adjustments | Maximum [Member]
Regulatory Liabilities [Line Items]
Regulatory Liability, Amortization Period		3 years
Other
Regulatory Liabilities [Line Items]
Regulatory Liability, Current		$ 6	5
Regulatory Liability, Noncurrent		$ 26	$ 22

[1] Includes the revaluation of recoverable/regulated plant accumulated deferred income taxes and revaluation impact of non-plant accumulated deferred income taxes due to the TCJA.

[2] Includes costs for conservation programs, as well as incentives allowed in certain jurisdictions.