CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 185	$ 241
Investment in marketable securities	836	822
Accounts receivable, less bad debt reserve	731	702
Bad debt reserve	47	21
Accrued unbilled revenues, less bad debt reserve	284	469
Accrued Unbilled Revenues, Allowance for Credit Losses, Current	2	0
Natural gas inventory	234	209
Materials and supplies	300	263
Taxes receivable	102	106
Current assets held for sale	0	1,002
Prepaid expenses and other current assets	113	123
Total current assets	2,785	3,937
Property, Plant and Equipment:
Property, plant and equipment	31,823	30,324
Less: accumulated depreciation and amortization	10,088	9,700
Property, plant and equipment, net	21,735	20,624
Other Assets:
Goodwill	4,697	4,882
Regulatory assets	2,150	2,117
Investment in unconsolidated affiliates	749	2,408
Preferred units – unconsolidated affiliate	363	363
Total non-current assets held for sale	0	962
Other	226	236
Total other assets	8,185	10,968
Total Assets	32,705	35,529
Current Liabilities:
Short-term borrowings	37	0
Current portion of VIE Securitization Bonds long-term debt	208	231
Indexed debt, net	16	19
Current portion of other long-term debt	1,114	618
Indexed debt securities derivative	918	893
Accounts payable	658	884
Taxes accrued	212	239
Interest accrued	117	158
Customer deposits	120	124
Non-trading derivative liabilities	1	7
Current liabilities held for sale	0	455
Other	429	350
Total current liabilities	3,830	3,978
Other Liabilities:
Deferred income taxes, net	3,575	3,928
Non-trading derivative liabilities	6	15
Benefit obligations	691	750
Regulatory liabilities	3,480	3,474
Total non-current liabilities held for sale	0	43
Other	789	738
Total other liabilities	8,541	8,948
Long-term Debt:
VIE Securitization Bonds, net	610	746
Other long-term debt, net	11,336	13,498
Total long-term debt, net	11,946	14,244
Commitments and Contingencies (Note 14)
Shareholders’ Equity:
Cumulative preferred stock, $0.01 par value, 20,000,000 shares authorized
Preferred Stock, Shares Authorized	20,000,000
Common stock	$ 5	$ 5
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Outstanding	544,819,895	502,242,061
Additional paid-in capital	$ 6,805	$ 6,080
Retained earnings (accumulated deficit)	(796)	632
Accumulated other comprehensive income (loss)	(82)	(98)
Total shareholders’ equity	8,388	8,359
Total Liabilities and Shareholders’ Equity	32,705	35,529
Variable Interest Entity, Primary Beneficiary [Member]
Current Assets:
Cash and cash equivalents	172	216
Accounts receivable, less bad debt reserve	30	26
Prepaid expenses and other current assets	16	19
Other Assets:
Regulatory assets	669	788
Houston Electric [Member]
Current Assets:
Cash and cash equivalents	172	216
Bad debt reserve	1	1
Accounts and notes receivable, less bad debt reserve	367	238
Accounts and notes receivable–affiliated companies	41	523
Accrued unbilled revenues, less bad debt reserve	124	117
Materials and supplies	182	147
Prepaid expenses and other current assets	32	49
Total current assets	918	1,290
Property, Plant and Equipment:
Property, plant and equipment	13,354	12,829
Less: accumulated depreciation and amortization	3,875	3,797
Property, plant and equipment, net	9,479	9,032
Other Assets:
Regulatory assets	873	915
Other	26	25
Total other assets	899	940
Total Assets	11,296	11,262
Current Liabilities:
Short-term borrowings	5	0
Current portion of VIE Securitization Bonds long-term debt	208	231
Current portion of other long-term debt	402	0
Accounts payable	256	268
Accounts and notes payable–affiliated companies	60	76
Taxes accrued	155	123
Interest accrued	45	69
Other	127	63
Total current liabilities	1,258	830
Other Liabilities:
Deferred income taxes, net	1,029	1,030
Benefit obligations	72	75
Regulatory liabilities	1,285	1,288
Other	87	69
Total other liabilities	2,473	2,462
Long-term Debt:
VIE Securitization Bonds, net	610	746
Other long-term debt, net	3,869	3,973
Total long-term debt, net	4,479	4,719
Commitments and Contingencies (Note 14)
Shareholders’ Equity:
Common stock	0	0
Additional paid-in capital	2,486	2,486
Retained earnings (accumulated deficit)	600	780
Accumulated other comprehensive income (loss)	0	(15)
Total shareholders’ equity	3,086	3,251
Total Liabilities and Shareholders’ Equity	11,296	11,262
Houston Electric [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Current Assets:
Cash and cash equivalents	172	216
Accounts receivable, less bad debt reserve	30	26
Prepaid expenses and other current assets	16	19
Other Assets:
Regulatory assets	669	788
CERC Corp [Member]
Current Assets:
Cash and cash equivalents	2	2
Accounts receivable, less bad debt reserve	231	322
Bad debt reserve	39	15
Accounts and notes receivable–affiliated companies	14	10
Accrued unbilled revenues, less bad debt reserve	90	249
Accrued Unbilled Revenues, Allowance for Credit Losses, Current	1	0
Natural gas inventory	152	135
Materials and supplies	68	71
Current assets held for sale	0	691
Prepaid expenses and other current assets	11	9
Total current assets	568	1,489
Property, Plant and Equipment:
Property, plant and equipment	8,608	8,079
Less: accumulated depreciation and amortization	2,408	2,270
Property, plant and equipment, net	6,200	5,809
Other Assets:
Goodwill	757	757
Regulatory assets	206	191
Total non-current assets held for sale	0	213
Other	48	53
Total other assets	1,011	1,214
Total Assets	7,779	8,512
Current Liabilities:
Short-term borrowings	31	0
Accounts payable	191	333
Accounts and notes payable–affiliated companies	44	47
Taxes accrued	68	84
Interest accrued	31	38
Customer deposits	76	74
Current liabilities held for sale	0	368
Other	165	167
Total current liabilities	606	1,111
Other Liabilities:
Deferred income taxes, net	509	470
Benefit obligations	84	80
Regulatory liabilities	1,216	1,219
Total non-current liabilities held for sale	0	27
Other	437	418
Total other liabilities	2,246	2,214
Long-term Debt:
Total long-term debt, net	2,582	2,546
Commitments and Contingencies (Note 14)
Shareholders’ Equity:
Common stock	0	0
Additional paid-in capital	1,829	2,116
Retained earnings (accumulated deficit)	506	515
Accumulated other comprehensive income (loss)	10	10
Total shareholders’ equity	2,345	2,641
Total Liabilities and Shareholders’ Equity	$ 7,779	$ 8,512
Series A Preferred Stock [Member]
Shareholders’ Equity:
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock aggregate liquidation preference	$ 800	$ 800
Preferred stock outstanding (in shares)	800,000	800,000
Preferred Stock, $0.01 par value	$ 790	$ 790
Series B Preferred Stock [Member]
Shareholders’ Equity:
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock aggregate liquidation preference	$ 978	$ 978
Preferred stock outstanding (in shares)	977,500	977,500
Preferred Stock, $0.01 par value	$ 950	$ 950
Series C Preferred Stock [Member]
Shareholders’ Equity:
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock aggregate liquidation preference	$ 725	$ 725
Preferred stock outstanding (in shares)	725,000	725,000
Preferred Stock, $0.01 par value	$ 716	$ 0
Cumulative Preferred Stock
Shareholders’ Equity:
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	20,000,000	20,000,000