Selected Balance Sheet Data - Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Inventory [Line Items]
Total Inventories	$ 28	$ 27
Materials and supplies
Inventory [Line Items]
Inventories	8	8
Fuel
Inventory [Line Items]
Inventories	12	9
Natural gas
Inventory [Line Items]
Inventories	$ 8	$ 10

Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
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-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant