Acquisition Activity (Tables)	12 Months Ended
	Dec. 31, 2021
Acquisition Activity [Abstract]
Total Purchase Price Paid	Purchase of outstanding InfraREIT shares and units $ 1,275Certain transaction costs of InfraREIT paid by Oncor through June 30, 2019 (a) 53Total purchase price paid through June 30, 2019 1,328Adjustments made in the period from June 30, 2019 through March 31, 2020 (4)Total purchase price paid $ 1,324________________(a)Represents certain transaction costs incurred by InfraREIT in connection with the transaction and paid by Oncor, including a $40 million management termination fee payable to an affiliate of Hunt Consolidated, Inc.
Assets And Liabilities Assumed	Purchase price allocation is as follows: As of May 16, 2019Assets acquired: Current assets $ 45Property, plant and equipment - net 1,800Goodwill 676Regulatory assets 16Other noncurrent assets 10Total assets acquired 2,547 Liabilities assumed: Short-term debt 115Other current liabilities 24Regulatory liabilities 148Liability in lieu of deferred income taxes 97Long-term debt, including due currently 839Total liabilities assumed 1,223Net assets acquired 1,324Total purchase price paid $ 1,324