CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows from Operating Activities:
Net income (loss)	$ (1,094)	$ 364
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	579	622
Depreciation and amortization on assets held for sale	0	31
Amortization of deferred financing costs	15	14
Amortization of intangible assets in non-utility cost of revenues	1	12
Deferred income taxes	(477)	(21)
Goodwill impairment and loss from reclassification to held for sale	172	0
Goodwill Impairment	185	0
Unrealized loss (gain) on marketable securities	69	(147)
Loss (gain) on indexed debt securities	(59)	154
Write-down of natural gas inventory	3	3
Equity in (earnings) losses of unconsolidated affiliates	1,432	(136)
Distributions from unconsolidated affiliates	109	149
Pension contributions	(5)	(29)
Changes in other assets and liabilities, excluding acquisitions:
Accounts receivable and unbilled revenues, net	312	463
Inventory	22	10
Taxes receivable	106	(69)
Accounts payable	(221)	(594)
Fuel cost recovery	15	78
Non-trading derivatives, net	(3)	(71)
Margin deposits, net	65	(12)
Interest and taxes accrued	14	(88)
Net regulatory assets and liabilities	(80)	(77)
Other current assets	1	20
Other current liabilities	(39)	(156)
Other assets	15	76
Other liabilities	41	(30)
Other operating activities, net	3	8
Net cash provided by operating activities from continuing operations	1,181	574
Cash Flows from Investing Activities:
Capital expenditures	(1,278)	(1,169)
Acquisitions, net of cash acquired	0	(5,987)
Increase in notes receivable – unconsolidated affiliate	0	(4)
Distributions from unconsolidated affiliate in excess of cumulative earnings	7	0
Proceeds from divestitures (Note 3)	(1,136)	0
Other investing activities, net	(8)	11
Net cash used in investing activities from continuing operations	(143)	(7,149)
Cash Flows from Financing Activities:
Increase in short-term borrowings, net	19	0
Proceeds from (payments of) commercial paper, net	(1,498)	2,221
Proceeds from long-term debt, net	299	1,721
Payments of long-term debt	(1,032)	(1,077)
Proceeds from (Repayments of) Lines of Credit	0	135
Payment of debt issuance costs	(3)	(9)
Payment of dividends on Common Stock	(227)	(288)
Payment of dividends on Preferred Stock	(66)	(60)
Proceeds from issuance of Common Stock, net	673	0
Proceeds from issuance of Series C Preferred Stock, net	724	0
Other financing activities, net	(4)	(14)
Net cash provided by (used in) financing activities from continuing operations	(1,115)	2,629
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(77)	(3,946)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	271	4,278
Cash, Cash Equivalents and Restricted Cash at End of Period	194	332
Houston Electric [Member]
Cash Flows from Operating Activities:
Net income (loss)	120	127
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	269	351
Amortization of deferred financing costs	5	5
Deferred income taxes	(10)	(27)
Changes in other assets and liabilities, excluding acquisitions:
Accounts receivable and unbilled revenues, net	(102)	(56)
Accounts receivable/payable–affiliated companies	(6)	(35)
Inventory	(28)	(7)
Taxes receivable	0	(8)
Accounts payable	9	2
Non-trading derivatives, net	15	(25)
Interest and taxes accrued	(2)	(34)
Net regulatory assets and liabilities	(13)	(69)
Other current assets	16	18
Other current liabilities	2	(4)
Other assets	(1)	10
Other liabilities	12	(3)
Other operating activities, net	(8)	(5)
Net cash provided by operating activities from continuing operations	278	240
Cash Flows from Investing Activities:
Capital expenditures	(548)	(514)
Increase in notes receivable – unconsolidated affiliate	448	(794)
Other investing activities, net	(7)	(3)
Net cash used in investing activities from continuing operations	(107)	(1,311)
Cash Flows from Financing Activities:
Increase in short-term borrowings, net	5	0
Proceeds from long-term debt, net	299	696
Payments of long-term debt	(132)	(242)
Decrease in notes payable–affiliated companies	0	(1)
Dividend to parent	(405)	(40)
Contribution from parent	0	590
Payment of debt issuance costs	(3)	(8)
Other financing activities, net	0	(1)
Net cash provided by (used in) financing activities from continuing operations	(236)	994
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(65)	(77)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	235	370
Cash, Cash Equivalents and Restricted Cash at End of Period	170	293
CERC Corp [Member]
Cash Flows from Operating Activities:
Net income (loss)	80	166
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	148	146
Depreciation and amortization on assets held for sale	0	7
Amortization of deferred financing costs	5	4
Deferred income taxes	26	20
Goodwill impairment and loss from reclassification to held for sale	93	0
Write-down of natural gas inventory	3	3
Changes in other assets and liabilities, excluding acquisitions:
Accounts receivable and unbilled revenues, net	357	554
Accounts receivable/payable–affiliated companies	(7)	(11)
Inventory	52	26
Accounts payable	(183)	(442)
Fuel cost recovery	14	78
Non-trading derivatives, net	(13)	(62)
Margin deposits, net	65	(12)
Interest and taxes accrued	(27)	(31)
Net regulatory assets and liabilities	(12)	15
Other current assets	2	7
Other current liabilities	(22)	(21)
Other assets	7	(2)
Other liabilities	5	3
Other operating activities, net	(6)	1
Net cash provided by operating activities from continuing operations	587	449
Cash Flows from Investing Activities:
Capital expenditures	(376)	(322)
Increase in notes receivable – unconsolidated affiliate	(9)	(66)
Proceeds from divestitures (Note 3)	(286)	0
Other investing activities, net	2	2
Net cash used in investing activities from continuing operations	(97)	(386)
Cash Flows from Financing Activities:
Increase in short-term borrowings, net	14	0
Proceeds from (payments of) commercial paper, net	(145)	22
Dividend to parent	(72)	(103)
Contribution from parent	0	0
Capital distribution to parent associated with the sale of CES	(286)	0
Other financing activities, net	(2)	(2)
Net cash provided by (used in) financing activities from continuing operations	(491)	(83)
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(1)	(20)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	2	25
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 1	$ 5