Condensed Statements of Consolidated Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash Flows from Operating Activities:
Net income (loss)	$ 614	$ (1,094)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	634	579
Amortization of deferred financing costs	15	15
Amortization of intangible assets in non-utility cost of revenues	0	1
Deferred income taxes	51	(477)
Goodwill impairment and loss from reclassification to held for sale	0	172
Goodwill impairment	0	185
Unrealized loss on marketable securities	(52)	69
Gain on indexed debt securities	51	(59)
Write-down of natural gas inventory	0	3
Equity in (earnings) losses of unconsolidated affiliates	(175)	1,432
Distributions from unconsolidated affiliates	77	109
Pension contributions	(8)	(5)
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net	220	312
Inventory	53	22
Taxes receivable	4	106
Accounts payable	(120)	(221)
Non-trading derivatives, net	(23)	(3)
Margin deposits, net	0	65
Interest and taxes accrued	(48)	14
Net regulatory assets and liabilities	(2,329)	(65)
Other current assets	24	1
Other current liabilities	(76)	(39)
Other non-current assets	0	15
Other non-current liabilities	7	41
Other, net	5	3
Net cash provided by (used in) operating activities	(1,076)	1,181
Cash Flows from Investing Activities:
Capital expenditures	(1,383)	(1,278)
Distributions from unconsolidated affiliate in excess of cumulative earnings	0	7
Proceeds from divestitures (Note 3)	0	1,136
Other, net	7	(8)
Net cash used in investing activities	(1,376)	(143)
Cash Flows from Financing Activities:
Increase (decrease) in short-term borrowings, net	(27)	19
Proceeds from (payments of) commercial paper, net	225	(1,498)
Proceeds from long-term debt	4,493	299
Payments of long-term debt	(1,960)	(1,032)
Borrowings from revolving credit facilities	0	1,050
Payments of revolving credit facilities	0	(1,050)
Payment of debt issuance costs	(37)	(3)
Payment of dividends on Common Stock	(183)	(227)
Payment of dividends on Preferred Stock	(65)	(66)
Proceeds from issuance of Common Stock, net	0	673
Proceeds from issuance of Series C Preferred Stock, net	0	724
Other, net	(4)	(4)
Net cash provided by (used in) financing activities from continuing operations	2,442	(1,115)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(10)	(77)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	167	271
Cash, Cash Equivalents and Restricted Cash at End of Period	157	194
Houston Electric
Cash Flows from Operating Activities:
Net income (loss)	156	120
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	302	269
Amortization of deferred financing costs	5	5
Deferred income taxes	(3)	(10)
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net	(56)	(102)
Accounts receivable/payable–affiliated companies	(72)	(6)
Inventory	(14)	(28)
Accounts payable	49	9
Non-trading derivatives, net	0	15
Interest and taxes accrued	4	(2)
Net regulatory assets and liabilities	(142)	(13)
Other current assets	21	16
Other current liabilities	(3)	2
Other non-current assets	9	(1)
Other non-current liabilities	8	12
Other, net	(10)	(8)
Net cash provided by (used in) operating activities	254	278
Cash Flows from Investing Activities:
Capital expenditures	(735)	(548)
Decrease (increase) in notes receivable–affiliated companies	(97)	448
Other, net	(5)	(7)
Net cash used in investing activities	(837)	(107)
Cash Flows from Financing Activities:
Increase (decrease) in short-term borrowings, net	0	5
Proceeds from long-term debt	1,096	299
Payments of long-term debt	(510)	(132)
Decrease in notes payable–affiliated companies	(8)	0
Payment of debt issuance costs	(12)	(3)
Dividend to parent	0	(405)
Capital distribution to parent associated with the sale of CES	0	0
Net cash provided by (used in) financing activities from continuing operations	566	(236)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(17)	(65)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	154	235
Cash, Cash Equivalents and Restricted Cash at End of Period	137	170
CERC Corp
Cash Flows from Operating Activities:
Net income (loss)	209	80
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	160	148
Amortization of deferred financing costs	8	5
Deferred income taxes	24	26
Goodwill impairment and loss from reclassification to held for sale	0	93
Write-down of natural gas inventory	0	3
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net	182	357
Accounts receivable/payable–affiliated companies	(8)	(7)
Inventory	23	52
Accounts payable	(76)	(183)
Non-trading derivatives, net	0	(13)
Margin deposits, net	0	65
Interest and taxes accrued	(13)	(27)
Net regulatory assets and liabilities	(2,004)	2
Other current assets	5	2
Other current liabilities	(33)	(22)
Other non-current assets	(9)	7
Other non-current liabilities	(31)	5
Other, net	0	(6)
Net cash provided by (used in) operating activities	(1,563)	587
Cash Flows from Investing Activities:
Capital expenditures	(327)	(376)
Decrease (increase) in notes receivable–affiliated companies	0	(9)
Proceeds from divestitures (Note 3)	0	286
Other, net	12	2
Net cash used in investing activities	(315)	(97)
Cash Flows from Financing Activities:
Increase (decrease) in short-term borrowings, net	(27)	14
Proceeds from (payments of) commercial paper, net	217	(145)
Proceeds from long-term debt	1,699	0
Payment of debt issuance costs	(10)	0
Dividend to parent	0	(72)
Capital distribution to parent associated with the sale of CES	0	(286)
Other, net	(1)	(2)
Net cash provided by (used in) financing activities from continuing operations	1,878	(491)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	0	(1)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	1	2
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 1	$ 1