Revenue from Contract with Customer - EEGH (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue from External Customer [Line Items]
Total operating revenue	$ 25,150	$ 20,952	$ 19,844
EEGH
Revenue from External Customer [Line Items]
Customer revenue	1,866	2,087	2,165
Other revenue	4	3	4
Total operating revenue	1,870	2,090	2,169
Regulated assets | Retail Gas
Revenue from External Customer [Line Items]
Customer revenue	974	619	686
Regulated assets | Wholesale
Revenue from External Customer [Line Items]
Customer revenue	727	366	457
Regulated assets | Other
Revenue from External Customer [Line Items]
Customer revenue	109	110	2
Regulated assets | EEGH
Revenue from External Customer [Line Items]
Customer revenue	1,099	1,289	1,316
Regulated assets | EEGH | Retail Gas
Revenue from External Customer [Line Items]
Customer revenue	1,044	1,242	1,300
Regulated assets | EEGH | Wholesale
Revenue from External Customer [Line Items]
Customer revenue	57	43	9
Regulated assets | EEGH | Other
Revenue from External Customer [Line Items]
Customer revenue	(2)	4	7
Nonregulated assets | EEGH
Revenue from External Customer [Line Items]
Customer revenue	$ 767	$ 798	$ 849