Acquisition Activity (Assets And Liabilities Assumed) (Details) - USD ($) $ in Thousands		1 Months Ended
	May 16, 2019	Mar. 31, 2020	May 31, 2019	Dec. 31, 2021	Dec. 31, 2020
Goodwill				$ 4,740,000	$ 4,740,000
InfraREIT [Member]
Current assets	$ 45,000
Property, plant and equipment - net	1,800,000
Goodwill	676,000		$ 676,000
Regulatory assets	16,000
Other noncurrent assets	10,000
Total assets acquired	2,547,000
Short-term debt	115,000
Other current liabilities	24,000
Regulatory liabilities	148,000
Liability in lieu of deferred income taxes	97,000
Long-term debt, including due currently	839,000
Total liabilities assumed	1,223,000
Net assets acquired	1,324,000
Total purchase price paid	$ 1,324,000	$ 1,324,000	$ 1,324,000