CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 293	$ 260
Investment in marketable securities	627	960
Accounts receivable, less bad debt reserve	918	1,000
Accrued unbilled revenues	212	427
Natural gas inventory	207	222
Materials and supplies	198	175
Non-trading derivative assets	76	110
Taxes receivable	38	0
Prepaid expenses and other current assets	157	241
Total current assets	2,726	3,395
Property, Plant and Equipment:
Property, plant and equipment	19,861	19,031
Less: accumulated depreciation and amortization	6,208	5,974
Property, plant and equipment, net	13,653	13,057
Other Assets:
Goodwill	867	867
Regulatory assets	1,934	2,347
Non-trading derivative assets	38	44
Investment in unconsolidated affiliate	2,457	2,472
Preferred units – unconsolidated affiliate	363	363
Other	190	191
Total other assets	5,849	6,284
Total Assets	22,228	22,736
Current Liabilities:
Short-term borrowings	0	39
Current portion of VIE Securitization Bonds long-term debt	456	434
Indexed debt, net	25	122
Current portion of other long-term debt	50	50
Indexed debt securities derivative	685	668
Accounts payable	708	963
Taxes accrued	152	181
Interest accrued	80	104
Dividends accrued	0	120
Non-trading derivative liabilities	33	20
Other	392	368
Total current liabilities	2,581	3,069
Other Liabilities:
Deferred income taxes, net	3,220	3,174
Non-trading derivative liabilities	6	4
Benefit obligations	722	785
Regulatory liabilities	2,506	2,464
Other	433	357
Total other liabilities	6,887	6,784
Long-term Debt:
VIE Securitization Bonds, net	1,045	1,434
Other long-term debt, net	6,207	6,761
Total long-term debt, net	7,252	8,195
Commitments and Contingencies (Note 14)
Shareholders’ Equity:
Cumulative preferred stock, $0.01 par value, 20,000,000 shares authorized
Common stock	4	4
Additional paid-in capital	4,221	4,209
Retained earnings	551	543
Accumulated other comprehensive income (loss)	(58)	(68)
Total shareholders’ equity	5,508	4,688
Total Liabilities and Shareholders’ Equity	22,228	22,736
Houston Electric [Member]
Current Assets:
Cash and cash equivalents	279	238
Accounts and notes receivable, less bad debt reserve	389	284
Accounts and notes receivable–affiliated companies	13	7
Accrued unbilled revenues	122	120
Materials and supplies	129	119
Non-trading derivative assets	3	0
Taxes receivable	9	0
Prepaid expenses and other current assets	50	62
Total current assets	994	830
Property, Plant and Equipment:
Property, plant and equipment	11,962	11,496
Less: accumulated depreciation and amortization	3,742	3,633
Property, plant and equipment, net	8,220	7,863
Other Assets:
Regulatory assets	1,202	1,570
Other	20	29
Total other assets	1,222	1,599
Total Assets	10,436	10,292
Current Liabilities:
Current portion of VIE Securitization Bonds long-term debt	456	434
Accounts payable	220	243
Accounts and notes payable–affiliated companies	113	104
Taxes accrued	88	116
Interest accrued	43	65
Other	111	120
Total current liabilities	1,031	1,082
Other Liabilities:
Deferred income taxes, net	1,044	1,059
Benefit obligations	142	146
Regulatory liabilities	1,265	1,263
Other	79	54
Total other liabilities	2,530	2,522
Long-term Debt:
VIE Securitization Bonds, net	1,045	1,434
Other long-term debt, net	3,281	2,885
Total long-term debt, net	4,326	4,319
Commitments and Contingencies (Note 14)
Shareholders’ Equity:
Common stock	0	0
Additional paid-in capital	1,696	1,696
Retained earnings	846	673
Accumulated other comprehensive income (loss)	7	0
Total shareholders’ equity	2,549	2,369
Total Liabilities and Shareholders’ Equity	10,436	10,292
CERC Corp [Member]
Current Assets:
Cash and cash equivalents	1	12
Accounts receivable, less bad debt reserve	527	713
Accounts and notes receivable–affiliated companies	9	6
Accrued unbilled revenues	90	307
Natural gas inventory	206	222
Materials and supplies	69	56
Non-trading derivative assets	73	110
Prepaid expenses and other current assets	85	166
Total current assets	1,060	1,592
Property, Plant and Equipment:
Property, plant and equipment	7,260	6,888
Less: accumulated depreciation and amortization	2,185	2,036
Property, plant and equipment, net	5,075	4,852
Other Assets:
Goodwill	867	867
Regulatory assets	170	181
Non-trading derivative assets	38	44
Investment in unconsolidated affiliate - discontinued operations	0	2,472
Other	95	104
Total other assets	1,170	3,668
Total Assets	7,305	10,112
Current Liabilities:
Short-term borrowings	0	39
Accounts payable	429	669
Accounts and notes payable–affiliated companies	44	611
Taxes accrued	64	75
Interest accrued	31	32
Customer deposits	74	76
Non-trading derivative liabilities	33	20
Other	171	137
Total current liabilities	846	1,659
Other Liabilities:
Deferred income taxes, net	370	362
Deferred income taxes, net - discontinued operations	0	927
Non-trading derivative liabilities	6	4
Benefit obligations	98	97
Regulatory liabilities	1,241	1,201
Other	350	297
Total other liabilities	2,065	2,888
Long-term Debt:
Total long-term debt, net	2,257	2,457
Commitments and Contingencies (Note 14)
Shareholders’ Equity:
Common stock	0	0
Additional paid-in capital	1,668	2,528
Retained earnings	463	574
Accumulated other comprehensive income (loss)	6	6
Total shareholders’ equity	2,137	3,108
Total Liabilities and Shareholders’ Equity	7,305	10,112
Series A Preferred Stock [Member]
Shareholders’ Equity:
Series A Preferred Stock, $0.01 par value, $800,000 aggregate liquidation preference, 800,000 shares outstanding	$ 790	$ 0