Revenue Recognition - Summary of Contract Assets and Liabilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
Accounts Receivable
Opening balance as of December 31, 2021	$ 627
Closing balance as of December 31, 2022	858
Increase (decrease) in accounts receivable	231
Other Accrued Unbilled Revenues
Opening balance as of December 31, 2021	513
Closing balance as of December 31, 2022	764
Increase (decrease) in other accrued unbilled revenues	251
Contract Assets
Opening balance as of December 31, 2021	15
Closing balance as of December 31, 2022	4
Increase (decrease) in contract with customer, asset	(11)
Contract Liabilities
Opening balance as of December 31, 2021	16
Closing balance as of December 31, 2022	45
Increase (decrease) in contract with customer, liability	29
Revenue recognized included in the opening contract liability for the period	15
Houston Electric
Accounts Receivable
Opening balance as of December 31, 2021	225
Closing balance as of December 31, 2022	271
Increase (decrease) in accounts receivable	46
Other Accrued Unbilled Revenues
Opening balance as of December 31, 2021	127
Closing balance as of December 31, 2022	142
Increase (decrease) in other accrued unbilled revenues	15
Contract Liabilities
Opening balance as of December 31, 2021	4
Closing balance as of December 31, 2022	2
Increase (decrease) in contract with customer, liability	(2)
Revenue recognized included in the opening contract liability for the period	4
CERC Corp
Accounts Receivable
Opening balance as of December 31, 2021	319
Closing balance as of December 31, 2022	478
Increase (decrease) in accounts receivable	159
Other Accrued Unbilled Revenues
Opening balance as of December 31, 2021	335
Closing balance as of December 31, 2022	573
Increase (decrease) in other accrued unbilled revenues	$ 238