Centerpoint Energy Houston Electric 10-K 27 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 19, 2020	Jun. 30, 2019
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Entity File Number	1-31447
Entity Registrant Name	CenterPoint Energy, Inc.
Entity Tax Identification Number	74-0694415
Entity Incorporation, State or Country Code	TX
Entity Address, Address Line One	1111 Louisiana
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	(713)
Local Phone Number	207-1111
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 14,295,717,409
Entity Common Stock, Shares Outstanding		502,243,185
Entity Central Index Key	0001130310
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Common Stock, $0.01 par value | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CNP
Security Exchange Name	NYSE
Common Stock, $0.01 par value | Chicago Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CNP
Security Exchange Name	CHX
Depositary shares, each representing a 1/20th interest in a share of 7.00% Series B Mandatory Convertible Preferred Stock, $0.01 par value | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Depositary shares, each representing a 1/20th interest in a share of 7.00% Series B Mandatory Convertible Preferred Stock, $0.01 par value
Trading Symbol	CNP/PB
Security Exchange Name	NYSE
CenterPoint Energy Houston Electric, LLC
Entity Information [Line Items]
Entity File Number	1-3187
Entity Registrant Name	CenterPoint Energy Houston Electric, LLC
Entity Tax Identification Number	22-3865106
Entity Incorporation, State or Country Code	TX
Entity Address, Address Line One	1111 Louisiana
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	(713)
Local Phone Number	207-1111
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			0
Entity Common Stock, Shares Outstanding		1,000
Entity Central Index Key	0000048732
CenterPoint Energy Houston Electric, LLC | 9.15% First Mortgage Bonds due 2021 | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	9.15% First Mortgage Bonds due 2021
Trading Symbol	n/a
Security Exchange Name	NYSE
CenterPoint Energy Houston Electric, LLC | 6.95% General Mortgage Bonds due 2033 | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	6.95% General Mortgage Bonds due 2033
Trading Symbol	n/a
Security Exchange Name	NYSE
CenterPoint Energy Resources Corp.
Entity Information [Line Items]
Entity File Number	1-13265
Entity Registrant Name	CenterPoint Energy Resources Corp.
Entity Tax Identification Number	76-0511406
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	1111 Louisiana
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77002
City Area Code	(713)
Local Phone Number	207-1111
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		1,000
Entity Central Index Key	0001042773
CenterPoint Energy Resources Corp. | 6.625% Senior Notes due 2037 | New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	6.625% Senior Notes due 2037
Trading Symbol	n/a
Security Exchange Name	NYSE

STATEMENTS OF CONSOLIDATED INCO

STATEMENTS OF CONSOLIDATED INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Utility revenues		$ 7,162	$ 6,163	$ 5,603
Non-utility revenues		5,139	4,426	4,011
Total		12,301	10,589	9,614
Expenses:
Utility natural gas, fuel and purchased power		1,683	1,410	1,109
Non-utility cost of revenues, including natural gas	[1]	4,029	4,364	3,785
Operation and maintenance		3,550	2,335	2,157
Depreciation and amortization		1,287	1,243	1,036
Taxes other than income taxes		478	406	391
Goodwill impairment		48	0	0
Total		11,075	9,758	8,478
Operating Income		1,226	831	1,136
Other Income (Expense):
Gain (loss) on marketable securities		282	(22)	7
Gain (loss) on indexed debt securities		(292)	(232)	49
Interest and other finance charges		(528)	(361)	(313)
Interest on Securitization Bonds		(39)	(59)	(77)
Equity in earnings of unconsolidated affiliates, net		230	307	265
Other, net		50	50	(4)
Total		(297)	(317)	(73)
Income Before Income Taxes		929	514	1,063
Income tax expense (benefit)		138	146	(729)
Net Income		791	368	1,792
Preferred stock dividend requirement		117	35	0
Income Available to Common Shareholders	[2]	$ 674	$ 333	$ 1,792
Basic Earnings Per Common Share		$ 1.34	$ 0.74	$ 4.16
Diluted Earnings Per Common Share		$ 1.33	$ 0.74	$ 4.13
Weighted Average Common Shares Outstanding, Basic		502,050,000	448,829,000	430,964,000
Weighted Average Common Shares Outstanding, Diluted		505,157,000	452,465,000	434,308,000
Houston Electric [Member]
Revenues:
Total		$ 2,990	$ 3,234	$ 2,998
Expenses:
Operation and maintenance		1,477	1,452	1,402
Depreciation and amortization		648	917	724
Taxes other than income taxes		247	240	235
Total		2,372	2,609	2,361
Operating Income		618	625	637
Other Income (Expense):
Interest and other finance charges		(164)	(138)	(128)
Interest on Securitization Bonds		(39)	(59)	(77)
Other, net		21	(3)	(8)
Total		(182)	(200)	(213)
Income Before Income Taxes		436	425	424
Income tax expense (benefit)		80	89	(9)
Net Income		356	336	433
CERC Corp [Member]
Revenues:
Utility revenues		2,911	2,931	2,606
Non-utility revenues		3,659	4,412	3,997
Total		6,570	7,343	6,603
Expenses:
Utility natural gas, fuel and purchased power		1,312	1,410	1,109
Non-utility cost of revenues, including natural gas	[1]	3,503	4,364	3,785
Operation and maintenance		890	898	816
Depreciation and amortization		305	293	279
Taxes other than income taxes		162	156	147
Goodwill impairment		48	0	0
Total		6,220	7,121	6,136
Operating Income		350	222	467
Other Income (Expense):
Interest and other finance charges		(116)	(122)	(123)
Other, net		(8)	(8)	(25)
Total		(124)	(130)	(148)
Income Before Income Taxes		226	92	319
Income tax expense (benefit)		14	22	(265)
Income From Continuing Operations		212	70	584
Income from discontinued operations (net of tax expense of $-0-, $46, and $104, respectively)		0	138	161
Net Income		$ 212	$ 208	$ 745
[1]	Income statement impact associated with cash flow hedge activity is related to gains and losses reclassified from Accumulated other comprehensive income into income. Amounts are immaterial for the years ended December 31, 2019 , 2018 and 2017 , respectively.
[2]	Income available to common shareholders for the year ended December 31, 2019 includes net income from businesses acquired in the Merger of $190 million . See Note 4. Income available to common shareholders for the year ended December 31, 2017 includes a reduction in income tax expense of $1,113 million due to tax reform. See Note 15 for further discussion of the impacts of the TCJA.

STATEMENTS OF CONSOLIDATED IN_2

STATEMENTS OF CONSOLIDATED INCOME (Parentheticals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CERC Corp [Member]
Income tax expense (benefit) associated with discontinued operations	$ 0	$ 46	$ 104

STATEMENTS OF CONSOLIDATED COMP

STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net income	$ 791	$ 368	$ 1,792
Other comprehensive income (loss):
Adjustment to pension and other postretirement plans	12	(10)	6
Net deferred gain (loss) from cash flow hedges	(2)	(15)	(3)
Reclassification of deferred loss from cash flow hedges realized in net income (net of tax expense of $-0-, $-0- and $-0-, respectively)	1	0	0
Other comprehensive loss from unconsolidated affiliates, net of tax	(1)	0	0
Other comprehensive income (loss)	10	(25)	3
Comprehensive income	801	343	1,795
Preferred stock dividend requirement	117	35	0
Comprehensive income	684	308	1,795
Houston Electric [Member]
Net income	356	336	433
Other comprehensive income (loss):
Net deferred gain (loss) from cash flow hedges	(1)	(14)	(1)
Other comprehensive income (loss)	(1)	(14)	(1)
Comprehensive income	355	322	432
CERC Corp [Member]
Net income	212	208	745
Other comprehensive income (loss):
Adjustment to pension and other postretirement plans	5	1	4
Net deferred gain (loss) from cash flow hedges	0	(1)	(1)
Other comprehensive income (loss)	5	0	3
Comprehensive income	$ 217	$ 208	$ 748

STATEMENTS OF CONSOLIDATED CO_2

STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tax benefit (expense) on adjustment related to pension and postretirement plans	$ (4)	$ 2	$ (6)
Tax expense (benefit) on net deferred gain (loss) from cash flow hedges	(1)	(4)	(2)
Tax expense (benefit) on deferred loss from cash flow hedges realized in net income	0	0	0
Houston Electric [Member]
Tax expense (benefit) on net deferred gain (loss) from cash flow hedges	0	(4)	0
CERC Corp [Member]
Tax benefit (expense) on adjustment related to pension and postretirement plans	(2)	(1)	(4)
Tax expense (benefit) on net deferred gain (loss) from cash flow hedges	$ 0	$ 0	$ (1)

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	[1]	$ 241	$ 4,231
Investment in marketable securities		822	540
Accounts receivable		1,249	1,190
Accrued unbilled revenues		586	378
Natural gas and coal inventory		277	194
Materials and supplies		269	200
Non-trading derivative assets		136	100
Taxes receivable		106	0
Prepaid expense and other current assets		161	192
Total current assets		3,847	7,025
Property, Plant and Equipment, net		20,945	14,044
Other Assets:
Goodwill		5,164	867
Regulatory assets		2,117	1,967
Non-trading derivative assets		58	38
Investment in unconsolidated affiliates		2,408	2,482
Preferred units - unconsolidated affiliate		363	363
Intangible Assets, Net (Excluding Goodwill)		321	65
Other		216	158
Total other assets		10,647	5,940
Total Assets		35,439	27,009
Current Liabilities:
Current portion of VIE Securitization Bonds long-term debt		231	458
Indexed debt, net		19	24
Current portion of other long-term debt		618	0
Indexed debt securities derivative		893	601
Accounts payable		1,138	1,240
Taxes accrued		241	204
Interest accrued		158	121
Dividends accrued		0	187
Customer deposits		125	86
Non-trading derivative liabilities		51	126
Other		414	255
Total current liabilities		3,888	3,302
Other Liabilities:
Deferred income taxes, net		3,928	3,239
Non-trading derivative liabilities		29	5
Benefit obligations		754	796
Regulatory liabilities		3,474	2,525
Other		763	402
Total other liabilities		8,948	6,967
Long-term Debt:
VIE Securitization Bonds, net		746	977
Other long-term debt, net		13,498	7,705
Total long-term debt, net		14,244	8,682
Commitments and Contingencies (Note 16)
Shareholders’ Equity:
Cumulative preferred stock, $0.01 par value, 20,000,000 shares authorized		0	0
Common stock		5	5
Additional paid-in capital		6,080	6,072
Retained earnings		632	349
Accumulated other comprehensive income (loss)		(98)	(108)
Total shareholders’ equity		8,359	8,058
Total Liabilities and Shareholders’ Equity		35,439	27,009
Houston Electric [Member]
Current Assets:
Cash and cash equivalents	[2]	216	335
Accounts and notes receivable, net		238	283
Accounts and notes receivable—affiliated companies		523	20
Accrued unbilled revenues		117	110
Materials and supplies		147	135
Taxes receivable		0	5
Prepaid expense and other current assets		49	61
Total current assets		1,290	949
Property, Plant and Equipment, net		9,032	8,402
Other Assets:
Regulatory assets		915	1,124
Other		25	32
Total other assets		940	1,156
Total Assets		11,262	10,507
Current Liabilities:
Current portion of VIE Securitization Bonds long-term debt		231	458
Accounts payable		268	262
Accounts and notes payable—affiliated companies		76	78
Taxes accrued		123	115
Interest accrued		69	64
Non-trading derivative liabilities		0	24
Other		63	89
Total current liabilities		830	1,090
Other Liabilities:
Deferred income taxes, net		1,030	1,023
Benefit obligations		75	91
Regulatory liabilities		1,288	1,298
Other		69	65
Total other liabilities		2,462	2,477
Long-term Debt:
VIE Securitization Bonds, net		746	977
Other long-term debt, net		3,973	3,281
Total long-term debt, net		4,719	4,258
Commitments and Contingencies (Note 16)
Shareholders’ Equity:
Common stock		0	0
Additional paid-in capital		2,486	1,896
Retained earnings		780	800
Accumulated other comprehensive income (loss)		(15)	(14)
Total shareholders’ equity		3,251	2,682
Total Liabilities and Shareholders’ Equity		11,262	10,507
CERC Corp [Member]
Current Assets:
Cash and cash equivalents		2	14
Accounts receivable		693	894
Accounts and notes receivable—affiliated companies		10	120
Accrued unbilled revenues		257	268
Natural gas and coal inventory		202	194
Materials and supplies		71	65
Non-trading derivative assets		136	100
Prepaid expense and other current assets		44	115
Total current assets		1,415	1,770
Property, Plant and Equipment, net		5,836	5,226
Other Assets:
Goodwill		819	867
Regulatory assets		191	181
Non-trading derivative assets		58	38
Other		120	132
Total other assets		1,188	1,218
Total Assets	[3]	8,439	8,214
Current Liabilities:
Accounts payable		557	856
Accounts and notes payable—affiliated companies		48	50
Taxes accrued		84	82
Interest accrued		38	38
Customer deposits		76	75
Non-trading derivative liabilities		44	102
Other		191	137
Total current liabilities		1,038	1,340
Other Liabilities:
Deferred income taxes, net		470	406
Non-trading derivative liabilities		14	5
Benefit obligations		83	93
Regulatory liabilities		1,219	1,227
Other		428	329
Total other liabilities		2,214	2,060
Long-term Debt:
Total long-term debt, net		2,546	2,371
Commitments and Contingencies (Note 16)
Shareholders’ Equity:
Common stock		0	0
Additional paid-in capital		2,116	2,015
Retained earnings		515	423
Accumulated other comprehensive income (loss)		10	5
Total shareholders’ equity		2,641	2,443
Total Liabilities and Shareholders’ Equity		8,439	8,214
Series A Preferred Stock [Member]
Shareholders’ Equity:
Preferred Stock		790	790
Series B Preferred Stock [Member]
Shareholders’ Equity:
Preferred Stock		$ 950	$ 950
[1]	CenterPoint Energy’s Cash and cash equivalents as of December 31, 2018 included $3.9 billion of temporary investments resulting from the Merger financings. CenterPoint Energy recorded interest income of $22 million , $28 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on CenterPoint Energy’s Statements of Consolidated Income. See Notes 13 and 14 for further details related to the Merger financings.
[2]	Houston Electric’s Cash and cash equivalents as of December 31, 2019 and 2018 included $216 million and $335 million , respectively, of cash related to the Bond Companies. Houston Electric recorded interest income of $9 million , $4 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on Houston Electric’s Statement of Consolidated Income.
[3]	On September 4, 2018, CERC completed the Internal Spin. For further information regarding the Internal Spin, see Note 11 .

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)		Dec. 31, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	[1]	$ 241,000,000	$ 4,231,000,000
Bad debt reserve		21,000,000	18,000,000
Accounts receivable		1,249,000,000	1,190,000,000
Prepaid expense and other current assets		161,000,000	192,000,000
Other Assets:
Regulatory assets		$ 2,117,000,000	$ 1,967,000,000
Shareholders’ Equity:
Cumulative preferred stock par value (in dollars per share)		$ 0.01	$ 0.01
Cumulative preferred stock authorized (in shares)		20,000,000	20,000,000
Common stock par value (in dollars per share)		$ 0.01	$ 0.01
Common stock authorized (in shares)		1,000,000,000	1,000,000,000
Common stock outstanding (in shares)		502,242,061	501,197,784
Variable Interest Entity, Primary Beneficiary [Member]
Current Assets:
Cash and cash equivalents		$ 216,000,000	$ 335,000,000
Accounts receivable		26,000,000	56,000,000
Prepaid expense and other current assets		19,000,000	34,000,000
Other Assets:
Regulatory assets		788,000,000	1,059,000,000
Houston Electric [Member]
Current Assets:
Cash and cash equivalents	[2]	216,000,000	335,000,000
Prepaid expense and other current assets		49,000,000	61,000,000
Other Assets:
Regulatory assets		915,000,000	1,124,000,000
Houston Electric [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Current Assets:
Cash and cash equivalents		216,000,000	335,000,000
Bad debt reserve		1,000,000	1,000,000
Accounts receivable		26,000,000	56,000,000
Prepaid expense and other current assets		19,000,000	34,000,000
Other Assets:
Regulatory assets		788,000,000	1,059,000,000
CERC Corp [Member]
Current Assets:
Cash and cash equivalents		2,000,000	14,000,000
Bad debt reserve		15,000,000	17,000,000
Accounts receivable		693,000,000	894,000,000
Prepaid expense and other current assets		44,000,000	115,000,000
Other Assets:
Regulatory assets		$ 191,000,000	$ 181,000,000
Cumulative Preferred Stock [Member]
Shareholders’ Equity:
Cumulative preferred stock par value (in dollars per share)		$ 0.01	$ 0.01
Cumulative preferred stock authorized (in shares)		20,000,000	20,000,000
Series A Preferred Stock [Member]
Shareholders’ Equity:
Cumulative preferred stock par value (in dollars per share)		$ 0.01	$ 0.01
Preferred Stock, Liquidation Preference, Value		$ 800,000,000	$ 800,000,000
Cumulative preferred stock outstanding (in shares)		800,000	800,000
Series B Preferred Stock [Member]
Shareholders’ Equity:
Cumulative preferred stock par value (in dollars per share)		$ 0.01	$ 0.01
Preferred Stock, Liquidation Preference, Value		$ 977,500,000	$ 977,500,000
Cumulative preferred stock outstanding (in shares)		977,500	977,500
[1]	CenterPoint Energy’s Cash and cash equivalents as of December 31, 2018 included $3.9 billion of temporary investments resulting from the Merger financings. CenterPoint Energy recorded interest income of $22 million , $28 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on CenterPoint Energy’s Statements of Consolidated Income. See Notes 13 and 14 for further details related to the Merger financings.
[2]	Houston Electric’s Cash and cash equivalents as of December 31, 2019 and 2018 included $216 million and $335 million , respectively, of cash related to the Bond Companies. Houston Electric recorded interest income of $9 million , $4 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on Houston Electric’s Statement of Consolidated Income.

STATEMENTS OF CONSOLIDATED CASH

STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities:
Net income	$ 791	$ 368	$ 1,792
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,287	1,243	1,036
Amortization of deferred financing costs	29	48	24
Deferred income taxes	69	48	(770)
Goodwill impairment charge recorded from annual impairment test	48	0	0
Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2)	24	0	0
Unrealized loss (gain) on marketable securities	(282)	22	(7)
Loss (gain) on indexed debt securities	292	232	(49)
Write-down of natural gas inventory	4	2	0
Income (Loss) from Equity Method Investments	(230)	(307)	(265)
Proceeds from Equity Method Investment, Distribution	261	267	0
Pension contributions	(109)	(69)	(48)
Changes in other assets and liabilities, excluding acquisitions:
Accounts receivable and unbilled revenues, net	226	(154)	(216)
Inventory	(52)	1	(7)
Taxes receivable	(106)	0	30
Accounts payable	(455)	220	136
Fuel cost recovery	92	33	(85)
Non-trading derivatives, net	(64)	103	(84)
Margin deposits, net	(56)	5	(55)
Interest and taxes accrued	54	40	5
Net regulatory assets and liabilities	(114)	28	(107)
Other current assets	(22)	0	(3)
Other current liabilities	(107)	(24)	34
Other assets	103	6	(4)
Other liabilities	(54)	12	36
Other, net	9	12	24
Net cash provided by operating activities	1,638	2,136	1,417
Cash Flows from Investing Activities:
Capital expenditures	(2,506)	(1,651)	(1,426)
Acquisitions, net of cash acquired	(5,991)	0	(132)
Distributions from unconsolidated affiliates in excess of cumulative earnings	42	30	297
Proceeds from sale of marketable securities	0	398	0
Proceeds from sale of assets	5	0	0
Purchase of investments	(6)	0	0
Other, net	35	16	4
Net cash provided by (used in) investing activities	(8,421)	(1,207)	(1,257)
Cash Flows from Financing Activities:
Increase (decrease) in short-term borrowings, net	0	(39)	4
Proceeds from (payments of) commercial paper, net	1,891	(1,543)	349
Proceeds from long-term debt, net	2,916	2,495	1,096
Payments of long-term debt	(1,302)	(484)	(1,211)
Loss on reacquired debt	0	0	(5)
Debt and equity issuance costs	(20)	(47)	(13)
Payment of dividends on Common Stock	(577)	(499)	(461)
Payment of dividends on preferred stock	(118)	(11)	0
Proceeds from issuance of Common Stock, net	0	1,844	0
Proceeds from issuance of preferred stock, net	0	1,740	0
Distribution to ZENS holders	0	(398)	0
Other, net	(14)	(5)	(4)
Net cash provided by (used in) financing activities	2,776	3,053	(245)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(4,007)	3,982	(85)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	4,278	296	381
Cash, Cash Equivalents and Restricted Cash at End of Year	271	4,278	296
Houston Electric [Member]
Cash Flows from Operating Activities:
Net income	356	336	433
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	648	917	724
Amortization of deferred financing costs	12	11	13
Deferred income taxes	(24)	(38)	(98)
Changes in other assets and liabilities, excluding acquisitions:
Accounts receivable and unbilled revenues, net	38	11	(73)
Accounts receivable/payable–affiliated companies	(23)	20	(46)
Inventory	(12)	(16)	15
Taxes receivable	5	(5)	6
Accounts payable	13	(1)	59
Non-trading derivatives, net	(25)	5	0
Interest and taxes accrued	13	(2)	7
Net regulatory assets and liabilities	(48)	(97)	(148)
Other current assets	(5)	(2)	(6)
Other current liabilities	(9)	(26)	16
Other assets	5	(3)	13
Other liabilities	(12)	17	(4)
Other, net	(14)	(12)	(6)
Net cash provided by operating activities	918	1,115	905
Cash Flows from Investing Activities:
Capital expenditures	(1,025)	(922)	(875)
(Increase) decrease in notes receivable–affiliated companies	(481)	0	96
Other, net	11	11	3
Net cash provided by (used in) investing activities	(1,495)	(911)	(776)
Cash Flows from Financing Activities:
Proceeds from long-term debt, net	696	398	298
Payments of long-term debt	(458)	(434)	(411)
Dividend to parent	(376)	(209)	(180)
Increase (decrease) in notes payable–affiliated companies	(1)	(59)	60
Debt issuance costs	(8)	(4)	(3)
Contribution from parent	590	200	0
Other, net	(1)	0	0
Net cash provided by (used in) financing activities	442	(108)	(236)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(135)	96	(107)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	370	274	381
Cash, Cash Equivalents and Restricted Cash at End of Year	235	370	274
CERC Corp [Member]
Cash Flows from Operating Activities:
Net income	212	208	745
Income (loss) from discontinued operations, net of tax	0	138	161
Income (loss) from continuing operations	212	70	584
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	305	293	279
Amortization of deferred financing costs	9	9	9
Deferred income taxes	7	31	(224)
Goodwill impairment charge recorded from annual impairment test	48	0	0
Write-down of natural gas inventory	4	2	0
Changes in other assets and liabilities, excluding acquisitions:
Accounts receivable and unbilled revenues, net	252	(155)	(143)
Accounts receivable/payable–affiliated companies	(6)	9	0
Inventory	(12)	17	(22)
Accounts payable	(305)	163	64
Fuel cost recovery	86	33	(85)
Non-trading derivatives, net	(60)	98	(82)
Margin deposits, net	(56)	5	(55)
Interest and taxes accrued	2	0	(41)
Net regulatory assets and liabilities	(10)	50	(27)
Other current assets	1	4	2
Other current liabilities	22	(3)	15
Other assets	5	5	(8)
Other liabilities	(38)	6	6
Other, net	0	1	6
Net cash provided by operating activities from continuing operations	466	638	278
Net cash provided by operating activities from discontinued operations	0	176	0
Net cash provided by operating activities	466	814	278
Cash Flows from Investing Activities:
Capital expenditures	(776)	(633)	(513)
Acquisitions, net of cash acquired	0	0	(132)
(Increase) decrease in notes receivable–affiliated companies	114	(114)	0
Other, net	0	3	2
Net cash used in investing activities from continuing operations	(662)	(744)	(643)
Net cash provided by investing activities from discontinued operations	0	47	297
Net cash provided by (used in) investing activities	(662)	(697)	(346)
Cash Flows from Financing Activities:
Increase (decrease) in short-term borrowings, net	0	(39)	4
Proceeds from (payments of) commercial paper, net	167	(688)	329
Proceeds from long-term debt, net	0	599	298
Payments of long-term debt	0	0	(550)
Dividend to parent	(120)	(360)	(601)
Increase (decrease) in notes payable–affiliated companies	0	(570)	570
Loss on reacquired debt	0	0	(5)
Debt issuance costs	0	(5)	(4)
Contribution from parent	129	960	38
Other, net	(3)	(1)	0
Net cash used in financing activities from continuing operations	173	(104)	79
Net cash provided by financing activities from discontinued operations	0	0	0
Net cash provided by (used in) financing activities	173	(104)	79
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(23)	13	11
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	25	12	1
Cash, Cash Equivalents and Restricted Cash at End of Year	$ 2	$ 25	$ 12

STATEMENTS OF CONSOLIDATED SHAR

STATEMENTS OF CONSOLIDATED SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Series A Preferred Stock [Member]	Series B Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock [Member]Series A Preferred Stock [Member]	Preferred Stock [Member]Series B Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Common Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member]Series A Preferred Stock [Member]	Retained Earnings [Member]Series B Preferred Stock [Member]	AOCI Attributable to Parent [Member]	Houston Electric [Member]	Houston Electric [Member]Common Stock [Member]	Houston Electric [Member]Additional Paid-in Capital [Member]	Houston Electric [Member]Retained Earnings [Member]	Houston Electric [Member]AOCI Attributable to Parent [Member]	CERC Corp [Member]		CERC Corp [Member]Common Stock [Member]	CERC Corp [Member]Additional Paid-in Capital [Member]	CERC Corp [Member]Retained Earnings [Member]	CERC Corp [Member]AOCI Attributable to Parent [Member]
Balance, beginning of year at Dec. 31, 2016				0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances of stock					0	0	0
Balance, end of year at Dec. 31, 2017				0
Balance, beginning of year at Dec. 31, 2016							431,000,000								1,000						1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans							0
Balance, end of year at Dec. 31, 2017							431,000,000								1,000						1,000
Balance, beginning of year at Dec. 31, 2016				$ 0			$ 4	$ 4,195		$ (668)			$ (71)		$ 0	$ 1,696	$ 420	$ 1			$ 0	$ 2,489	$ 430	$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans							0	14
Issuances of stock					$ 0	$ 0	0		$ 0
Contribution From Parent																0						38
Capital distribution associated with the Internal Spin	$ 0													$ 0					$ 0			0
Other																						1
Net income	1,792									1,792				433			433		745				745
Common Stock dividends declared ($0.8625, $1.1200 and $1.3475 per share, respectively)										(581)
Preferred stock dividends declared											$ 0	$ 0
Dividend to parent																	(180)						(601)
Other comprehensive income (loss)													3					(1)						3
Balance, end of year at Dec. 31, 2017	$ 4,688			$ 0			$ 4	4,209		543			(68)	2,369	$ 0	1,696	673	0	3,108		$ 0	2,528	574	6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU 2018-02 | Adjustments for New Accounting Principle, Early Adoption [Member]										0			0										0	0
Issuances of stock					1,000,000	1,000,000	70,000,000
Balance, end of year at Dec. 31, 2018		800,000	977,500	2,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans							0
Balance, end of year at Dec. 31, 2018	501,197,784						501,000,000								1,000						1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans							$ 0	19
Issuances of stock					$ 790	$ 950	1		1,844
Contribution From Parent																200						960
Capital distribution associated with the Internal Spin	$ 0													0					(1,473)	[1]		1,473
Other																						0
Net income	368									368				336			336		208				208
Common Stock dividends declared ($0.8625, $1.1200 and $1.3475 per share, respectively)										(523)
Preferred stock dividends declared		$ (26)	$ (28)								(26)	(28)
Dividend to parent																	(209)						(360)
Other comprehensive income (loss)													(25)					(14)						0
Balance, end of year at Dec. 31, 2018	$ 8,058			$ 1,740			$ 5	6,072		349			(108)	2,682	$ 0	1,896	800	(14)	2,443		$ 0	2,015	423	5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU 2018-02 | Adjustments for New Accounting Principle, Early Adoption [Member]										15			(15)										1	(1)
Issuances of stock					0	0	0
Balance, end of year at Dec. 31, 2019		800,000	977,500	2,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans							1,000,000
Balance, end of year at Dec. 31, 2019	502,242,061						502,000,000								1,000						1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans							$ 0	8
Issuances of stock					$ 0	$ 0	0		$ 0
Contribution From Parent																590						129
Capital distribution associated with the Internal Spin	$ 0													0					(28)	[1],[2]		28
Other																						0
Net income	791									791				356			356		212				212
Common Stock dividends declared ($0.8625, $1.1200 and $1.3475 per share, respectively)										(433)
Preferred stock dividends declared		$ (24)	$ (51)								$ (24)	$ (51)
Dividend to parent																	(376)						(120)
Other comprehensive income (loss)													10					(1)						5
Balance, end of year at Dec. 31, 2019	$ 8,359			$ 1,740			$ 5	$ 6,080		632			(98)	$ 3,251	$ 0	$ 2,486	$ 780	$ (15)	$ 2,641		$ 0	$ 2,116	515	10
Balance, end of year (Adjustments for New Accounting Principle, Early Adoption [Member]) at Dec. 31, 2019																								2,641
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU 2018-02 | Adjustments for New Accounting Principle, Early Adoption [Member]										$ 0			$ 0										$ 0	$ 0
[1]	The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.
[2]	The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.

STATEMENTS OF CONSOLIDATED SH_2

STATEMENTS OF CONSOLIDATED SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	Oct. 17, 2019	Jul. 31, 2019	Apr. 25, 2019	Dec. 12, 2018	Oct. 23, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 22, 2018
Cumulative preferred stock par value (in dollars per share)						$ 0.01	$ 0.01	$ 0.01
Cumulative preferred stock shares authorized (in shares)						20,000,000	20,000,000	20,000,000
Common stock shares par value (in dollars per share)						$ 0.01	$ 0.01	$ 0.01
Common stock shares authorized (in shares)						1,000,000,000	1,000,000,000	1,000,000,000
Common stock dividends declared per share						$ 0.86	$ 1.1200	$ 1.35
Series A Preferred Stock [Member]
Cumulative preferred stock par value (in dollars per share)						0.01	0.01		$ 1,000
Preferred stock dividends declared per share		$ 30.6250		$ 32.1563		30.6250	32.1563	0
Series B Preferred Stock [Member]
Cumulative preferred stock par value (in dollars per share)						0.01	0.01
Preferred stock dividends declared per share	$ 17.5000	$ 17.5000	$ 17.5000	$ 17.5000	$ 11.6667	$ 52.5000	$ 29.1667	$ 0

Background

Background	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background [Text Block]	Background General. This combined Form 10-K is filed separately by three registrants: CenterPoint Energy, Inc., CenterPoint Energy Houston Electric, LLC and CenterPoint Energy Resources Corp. Information contained herein relating to any individual registrant is filed by such registrant solely on its own behalf. Each registrant makes no representation as to information relating exclusively to the other Registrants or the subsidiaries of CenterPoint Energy other than itself or its subsidiaries. Except as discussed in Note 14 to the Registrants’ Consolidated Financial Statements, no registrant has an obligation in respect of any other Registrant’s debt securities, and holders of such debt securities should not consider the financial resources or results of operations of any Registrant other than the obligor in making a decision with respect to such securities. Included in this combined Form 10-K are the Financial Statements of CenterPoint Energy, Houston Electric and CERC, which are referred to collectively as the Registrants. The Combined Notes to the Consolidated Financial Statements apply to all Registrants and specific references to Houston Electric and CERC herein also pertain to CenterPoint Energy, unless otherwise indicated. Background. CenterPoint Energy, Inc. is a public utility holding company and owns interests in Enable as described below. On the Merger Date, pursuant to the Merger Agreement, CenterPoint Energy consummated the previously announced Merger and acquired Vectren for approximately $6 billion in cash. On the Merger Date, Vectren became a wholly-owned subsidiary of CenterPoint Energy. As of December 31, 2019 , CenterPoint Energy’s operating subsidiaries were as follows: • Houston Electric owns and operates electric transmission and distribution facilities in the Texas Gulf Coast area that includes the city of Houston; and • CERC Corp. (i) owns and operates natural gas distribution systems in six states and (ii) obtains and offers competitive variable and fixed-price physical natural gas supplies and services primarily to commercial and industrial customers and electric and natural gas utilities in over 30 states through its wholly-owned subsidiary, CES. • Vectren holds three public utilities through its wholly-owned subsidiary, VUHI, a public utility holding company: • Indiana Gas provides energy delivery services to natural gas customers located in central and southern Indiana; • SIGECO provides energy delivery services to electric and natural gas customers located near Evansville in southwestern Indiana and owns and operates electric generation assets to serve its electric customers and optimizes those assets in the wholesale power market; and • VEDO provides energy delivery services to natural gas customers located near Dayton in west-central Ohio. • Vectren performs non-utility activities through: • Infrastructure Services, which provides underground pipeline construction and repair services through wholly-owned subsidiaries Miller Pipeline, LLC and Minnesota Limited, LLC and serves natural gas utilities across the United States, focusing on recurring integrity, station and maintenance work and opportunities for large transmission pipeline construction projects; and • ESG, which provides energy performance contracting and sustainable infrastructure services, such as renewables, distributed generation and combined heat and power projects. For a description of CenterPoint Energy’s and CERC’s reportable segments, see Note 19 . Houston Electric consists of a single reportable segment, Houston Electric T&D. As of December 31, 2019 , CenterPoint Energy, indirectly through CNP Midstream, owned approximately 53.7% of the common units representing limited partner interests in Enable, 50% of the management rights and 40% of the incentive distribution rights in Enable GP and also directly owned an aggregate of 14,520,000 Enable Series A Preferred Units. Enable owns, operates and develops natural gas and crude oil infrastructure assets. On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies (a) Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. (b) Principles of Consolidation The accounts of the Registrants and their wholly-owned and majority-owned and controlled subsidiaries are included in the consolidated financial statements. All intercompany transactions and balances are eliminated in consolidation, except as described below. Businesses within the Infrastructure Services reportable segment provide underground pipeline construction and repair services for customers that include NGD utilities. In accordance with consolidation guidance in ASC 980—Regulated Operations, costs incurred by NGD utilities for these pipeline construction and repair services are not eliminated in consolidation when capitalized and included in rate base by the NGD utility. Fees incurred by CenterPoint Energy’s and CERC’s NGD for pipeline construction and repair services that were capitalized totaled $162 million and $20 million , respectively, for the 11 months ended December 31, 2019. On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. As of December 31, 2019 , CenterPoint Energy and Houston Electric had VIEs consisting of the Bond Companies, which are consolidated. The consolidated VIEs are wholly-owned, bankruptcy remote special purpose entities that were formed solely for the purpose of securitizing transition and system restoration related property. Creditors of CenterPoint Energy and Houston Electric have no recourse to any assets or revenues of the Bond Companies. The bonds issued by these VIEs are payable only from and secured by transition and system restoration property and the bondholders have no recourse to the general credit of CenterPoint Energy or Houston Electric. (c) Equity and Investments without a Readily Determinable Fair Value (CenterPoint Energy) CenterPoint Energy generally uses the equity method of accounting for investments in entities in which it has an ownership interest between 20% and 50% and exercises significant influence. CenterPoint Energy also uses the equity method for investments in which it has ownership percentages greater than 50%, when it exercises significant influence, does not have control and is not considered the primary beneficiary, if applicable. Under the equity method, CenterPoint Energy adjusts its investments each period for contributions made, distributions received, respective shares of comprehensive income and amortization of basis differences, as appropriate. CenterPoint Energy evaluates its equity method investments for impairment when events or changes in circumstances indicate there is a loss in value of the investment that is other than a temporary decline. CenterPoint Energy considers distributions received from equity method investments which do not exceed cumulative equity in earnings subsequent to the date of investment to be a return on investment and classifies these distributions as operating activities in its Statements of Consolidated Cash Flows. CenterPoint Energy considers distributions received from equity method investments in excess of cumulative equity in earnings subsequent to the date of investment to be a return of investment and classifies these distributions as investing activities in its Statements of Consolidated Cash Flows. Investments without a readily determinable fair value will be measured at cost, less impairment, plus or minus observable prices changes of an identical or similar investment of the same issuer. (d) Revenues The Registrants record revenue for electricity delivery and natural gas sales and services under the accrual method and these revenues are recognized upon delivery to customers. Electricity deliveries not billed by month-end are accrued based on actual AMS data, daily supply volumes and applicable rates. Natural gas sales not billed by month-end are accrued based upon estimated purchased gas volumes, estimated lost and unaccounted for gas and currently effective tariff rates. Revenue for some pipeline construction services are based on the percentage of completion method. For further discussion, see Note 5 . (e) MISO Transactions Indiana Electric is a member of the MISO. MISO-related purchase and sale transactions are recorded using settlement information provided by the MISO. These purchase and sale transactions are accounted for on at least a net hourly position, meaning net purchases within that interval are recorded on CenterPoint Energy’s Statements of Consolidated Income in Utility natural gas, fuel and purchased power, and net sales within that interval are recorded on CenterPoint Energy’s Statements of Consolidated Income in Utility revenues. On occasion, prior period transactions are resettled outside the routine process due to a change in the MISO’s tariff or a material interpretation thereof. Expenses associated with resettlements are recorded once the resettlement is probable and the resettlement amount can be estimated. Revenues associated with resettlements are recognized when the amount is determinable and collectability is reasonably assured. (f) Guarantees CenterPoint Energy recognizes guarantee obligations at fair value. CenterPoint Energy discloses parent company guarantees of a subsidiary’s obligation when that guarantee results in the exposure of a material obligation of the parent company even if the probability of fulfilling such obligation is considered remote. See Note 16(c) and (d). (g) Long-lived Assets, Goodwill and Intangibles The Registrants record property, plant and equipment at historical cost and expense repair and maintenance costs as incurred. The Registrants periodically evaluate long-lived assets, including property, plant and equipment, and specifically identifiable intangibles subject to amortization, when events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. For rate regulated businesses, recoverability of long-lived assets is assessed by determining if a capital disallowance from a regulator is probable through monitoring the outcome of rate cases and other proceedings. For non-rate regulated businesses, recoverability is assessed based on an estimate of undiscounted cash flows attributable to the assets compared to the carrying value of the assets. As of December 31, 2019, CenterPoint Energy and CERC, as applicable, determined that the carrying value of long-lived and intangible assets associated with the Infrastructure Services and Energy Services reporting units were recoverable based on undiscounted cash flows, considering the likelihood of possible outcomes existing as of that date, including the assessment of the likelihood of a future sale of these assets. No long-lived asset or intangible asset impairments were recorded in 2019, 2018 or 2017. CenterPoint Energy and CERC perform goodwill impairment tests at least annually and evaluate goodwill when events or changes in circumstances indicate that its carrying value may not be recoverable. Subsequent to the Registrant’s adoption of ASU 2017-04 Simplifying the Test for Goodwill Impairment on January 1, 2018, CenterPoint Energy and CERC recognize a goodwill impairment by the amount a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill within that reporting unit. CenterPoint Energy includes deferred tax assets and liabilities within its reporting unit’s carrying value for the purposes of annual and interim impairment tests, regardless of whether the estimated fair value reflects the disposition of such assets and liabilities. For further information about the goodwill impairment tests during 2019, see Note 6. (h) Assets Held for Sale and Discontinued Operations Generally, a long-lived asset to be sold is classified as held for sale in the period in which management, with approval from the Board of Directors, as applicable, commits to a plan to sell and a sale is expected to be completed within one year. The Registrants record assets and liabilities held for sale at the lower of their carrying value or their estimated fair value less cost to sell. If the disposal group reflects a component of a reporting unit and meets the definition of a business, the goodwill within that reporting unit is allocated to the disposal group based on the relative fair value of the components representing a business that will be retained and disposed. Goodwill is not allocated to a portion of a reporting unit that does not meet the definition of a business. A disposal group that meets the held for sale criteria and also represents a strategic shift to the Registrant, is also reflected as discontinued operations on the Statements of Consolidated Income, and prior periods are recast to reflect the earnings or losses from such businesses as income from discontinued operations, net of tax. (i) Regulatory Assets and Liabilities The Registrants apply the guidance for accounting for regulated operations to the Houston Electric T&D reportable segment, Indiana Electric Integrated segment and the Natural Gas Distribution reportable segment. The Registrants’ rate-regulated subsidiaries may collect revenues subject to refund pending final determination in rate proceedings. In connection with such revenues, estimated rate refund liabilities are recorded which reflect management’s current judgment of the ultimate outcomes of the proceedings. The Registrants’ rate-regulated businesses recognize removal costs as a component of depreciation expense in accordance with regulatory treatment. In addition, a portion of the amount of removal costs collected from customers that relate to AROs has been reflected as an asset retirement liability in accordance with accounting guidance for AROs. For further detail on the Registrants’ regulatory assets and liabilities, see Note 7 . (j) Depreciation and Amortization Expense The Registrants compute depreciation and amortization using the straight-line method based on economic lives or regulatory-mandated recovery periods. Amortization expense includes amortization of certain regulatory assets and other intangibles. (k) Capitalization of Interest and AFUDC The Registrants capitalize interest and AFUDC as a component of projects under construction and amortize it over the assets’ estimated useful lives once the assets are placed in service. AFUDC represents the composite interest cost of borrowed funds and a reasonable return on the equity funds used for construction for subsidiaries that apply the guidance for accounting for regulated operations. Although AFUDC increases both utility plant and earnings, it is realized in cash when the assets are included in rates. Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Interest and AFUDC debt (1) $ 36 $ 8 $ 3 $ 8 $ 6 $ 2 $ 9 $ 6 $ 2 AFUDC equity (2) 22 15 3 12 10 2 11 10 1 (1) Included in Interest and other finance charges on the Registrants’ respective Statements of Consolidated Income. (2) Included in Other Income (Expense) on the Registrants’ respective Statements of Consolidated Income. (l) Income Taxes Houston Electric and CERC are included in CenterPoint Energy’s U.S. federal consolidated income tax return. Houston Electric and CERC report their income tax provision on a separate entity basis pursuant to a tax sharing agreement with CenterPoint Energy. Current federal and certain state income taxes are payable to or receivable from CenterPoint Energy. The Registrants use the asset and liability method of accounting for deferred income taxes. Deferred income tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. A valuation allowance is established against deferred tax assets for which management believes realization is not considered to be more likely than not. The Registrants recognize interest and penalties as a component of income tax expense (benefit), as applicable, in their respective Statements of Consolidated Income. CenterPoint Energy reports the income tax provision associated with its interest in Enable in income tax expense (benefit) in its Statements of Consolidated Income. On December 22, 2017, President Trump signed into law comprehensive tax reform legislation informally called the Tax Cuts and Jobs Acts, or TCJA, which resulted in significant changes to federal tax laws effective January 1, 2018. See Note 15 for further discussion of the impacts of tax reform implementation. To the extent certain EDIT of the Registrants’ rate-regulated subsidiaries may be recoverable or payable through future rates, regulatory assets and liabilities have been recorded, respectively. The Registrants use the portfolio approach to recognize income tax effects on other comprehensive income from accumulated other comprehensive income. Investment tax credits are deferred and amortized to income over the approximate lives of the related property. (m) Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount and do not bear interest. Management reviews the outstanding accounts receivable, as well as the bad debt write-offs experienced in the past, and establishes an allowance for doubtful accounts. Account balances are charged off against the allowance when management determines it is probable the receivable will not be recovered. The table below summarizes the Registrants’ provision for doubtful accounts for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Provision for doubtful accounts $ 16 $ — $ 12 $ 16 $ — $ 16 $ 14 $ 1 $ 13 (n) Inventory The Registrants’ inventory consists principally of materials and supplies, and for CERC, natural gas, and for CenterPoint Energy, coal inventory. Materials and supplies are valued at the lower of average cost or market. Materials and supplies are recorded to inventory when purchased and subsequently charged to expense or capitalized to plant when installed. Natural gas inventories of CERC’s Energy Services reportable segment at locations qualifying for and utilizing the fair value hedge accounting election are valued at fair value; inventories at locations not qualifying for or not utilizing the fair value hedge accounting election are valued at the lower of average cost or market. During 2019 , 2018 and 2017 , CERC recorded write-downs of natural gas inventory to the lower of average cost or market which are disclosed on the respective Statements of Consolidated Cash Flows. (o) Derivative Instruments The Registrants are exposed to various market risks. These risks arise from transactions entered into in the normal course of business. The Registrants utilize derivative instruments such as physical forward contracts, swaps and options to mitigate the impact of changes in commodity prices, weather and interest rates on operating results and cash flows. Such derivatives are recognized in the Registrants’ Consolidated Balance Sheets at their fair value unless the Registrant elects the normal purchase and sales exemption for qualified physical transactions. A derivative may be designated as a normal purchase or normal sale if the intent is to physically receive or deliver the product for use or sale in the normal course of business. CenterPoint Energy and CERC have elected to record changes in the fair value of amounts excluded from the assessment of effectiveness immediately in their Statements of Consolidated Income. CenterPoint Energy has a Risk Oversight Committee composed of corporate and reportable segment officers that oversees commodity price, weather and credit risk activities, including the Registrants’ marketing, risk management services and hedging activities. The committee’s duties are to establish the Registrants’ commodity risk policies, allocate board-approved commercial risk limits, approve the use of new products and commodities, monitor positions and ensure compliance with the Registrants’ risk management policies and procedures and limits established by CenterPoint Energy’s Board of Directors. The Registrants’ policies prohibit the use of leveraged financial instruments. A leveraged financial instrument, for this purpose, is a transaction involving a derivative whose financial impact will be based on an amount other than the notional amount or volume of the instrument. (p) Investments in Equity Securities (CenterPoint Energy and CERC) CenterPoint Energy and CERC report equity securities at estimated fair value in their respective Consolidated Balance Sheets, and any unrealized holding gains and losses are recorded as Other Income (Expense) in their respective Statements of Consolidated Income. (q) Environmental Costs The Registrants expense or capitalize environmental expenditures, as appropriate, depending on their future economic benefit. The Registrants expense amounts that relate to an existing condition caused by past operations that do not have future economic benefit. The Registrants record undiscounted liabilities related to these future costs when environmental assessments and/or remediation activities are probable and the costs can be reasonably estimated. (r) Cash and Cash Equivalents and Restricted Cash For purposes of reporting cash flows, the Registrants consider cash equivalents to be short-term, highly-liquid investments with maturities of three months or less from the date of purchase. Cash and cash equivalents held by the Bond Companies (VIEs) solely to support servicing the Securitization Bonds as of December 31, 2019 and 2018 are reflected on CenterPoint Energy’s and Houston Electric’s Consolidated Balance Sheets. In connection with the issuance of Securitization Bonds, CenterPoint Energy and Houston Electric were required to establish restricted cash accounts to collateralize the bonds that were issued in these financing transactions. These restricted cash accounts are not available for withdrawal until the maturity of the bonds and are not included in cash and cash equivalents. For more information on restricted cash see Note 20 . (s) Preferred Stock and Dividends Preferred stock is evaluated to determine balance sheet classification, and all conversion and redemption features are evaluated for bifurcation treatment. Proceeds received net of issuance costs are recognized on the settlement date. Cash dividends become a liability once declared. Income available to common stockholders is computed by deducting from net income the dividends accumulated and earned during the period on cumulative preferred stock. (t) Purchase Accounting The Registrants evaluate acquisitions to determine when a set of acquired activities and assets represent a business. When control of a business is obtained, the Registrants apply the acquisition method of accounting and record the assets acquired, liabilities assumed and any non-controlling interest obtained based on fair value at the acquisition date. The excess of the fair value of purchase consideration over the fair value of the net assets acquired is recorded as goodwill. The results of operations of the acquired business are included in the Registrants’ respective Statements of Consolidated Income beginning on the date of the acquisition. (u) New Accounting Pronouncements The following table provides an overview of certain recently adopted or issued accounting pronouncements applicable to all the Registrants, unless otherwise noted. Recently Adopted Accounting Standards ASU Number and Name Description Date of Adoption Financial Statement Impact upon Adoption ASU 2016-02- Leases (Topic 842) and related amendments ASU 2016-02 provides a comprehensive new lease model that requires lessees to recognize assets and liabilities for most leases and would change certain aspects of lessor accounting. Transition method: modified retrospective January 1, 2019 The Registrants adopted the standard and recognized a right-of-use asset and lease liability on their statement of financial position with no material impact on their results of operations and cash flows. See Note 22 for more information. Issued, Not Yet Effective Accounting Standards ASU Number and Name Description Effective Date Financial Statement Impact upon Adoption ASU 2016-13- Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments This standard, including standards amending this standard, requires a new model called CECL to estimate credit losses for (1) financial assets subject to credit losses and measured at amortized cost and (2) certain off-balance sheet credit exposures. Upon initial recognition of the exposure, the CECL model requires an entity to estimate the credit losses expected over the life of an exposure based on historical information, current information and reasonable and supportable forecasts, including estimates of prepayments. Transition method : modified retrospective January 1, 2020 Early adoption is permitted The adoption of this standard will result in an immaterial adjustment to the carrying value of the Registrants’ accounts receivable, net. The adoption of this standard will not have a material impact on the Registrants’ financial position, results of operations or cash flows. ASU 2018-13- Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement This standard eliminates, modifies and adds certain disclosure requirements for fair value measurements. Transition method : prospective for additions and one modification and retrospective for all other amendments Adoption of eliminations and modifications as of September 30, 2018; Additions will be adopted January 1, 2020 The adoption of this standard did not impact the Registrants’ financial position, results of operations or cash flows. Note 10 reflects the disclosures modified upon adoption. ASU 2018-15-Intangibles-Goodwill and Other- Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract This standard aligns accounting for implementation costs incurred in a cloud computing arrangement that is accounted for as a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The update also prescribes the balance sheet, income statement and cash flow classification of the capitalized implementation costs and related amortization expense and requires additional quantitative and qualitative disclosures. Transition method : retrospective or prospective January 1, 2020 Early adoption is permitted The adoption of this standard will require the Registrants to capitalize certain costs to implement cloud computing arrangements that are accounted for as service contracts within Prepaid expenses and other current assets on the Registrants’ consolidated balance sheets and record the amortization of such assets within Operation and maintenance expenses on the Registrants’ statements of consolidated income. The adoption of this standard will not have a material impact on the Registrants’ financial position, results of operations, cash flows or disclosures. Management believes that other recently adopted standards and recently issued standards that are not yet effective will not have a material impact on the Registrants’ financial position, results of operations or cash flows upon adoption.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Text Block]	Property, Plant and Equipment (a) Property, Plant and Equipment Property, plant and equipment includes the following: December 31, 2019 December 31, 2018 Weighted Average Useful Lives Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net (in years) (in millions) CenterPoint Energy Electric Transmission & Distribution 37 $ 14,360 $ 4,634 $ 9,726 $ 12,148 $ 3,746 $ 8,402 Electric Generation (1) 27 1,780 698 1,082 — — — Natural Gas Distribution 29 12,695 3,731 8,964 7,257 2,128 5,129 Energy Services (2) 27 136 53 83 121 43 78 Infrastructure Services (3) 10 317 22 295 — — — Other property 19 1,397 602 795 741 306 435 Total $ 30,685 $ 9,740 $ 20,945 $ 20,267 $ 6,223 $ 14,044 Houston Electric Electric Transmission 46 $ 3,358 $ 674 $ 2,684 $ 3,077 $ 650 $ 2,427 Electric Distribution 35 7,876 2,586 5,290 7,524 2,553 4,971 Other transmission & distribution property 19 1,595 537 1,058 1,547 543 1,004 Total $ 12,829 $ 3,797 $ 9,032 $ 12,148 $ 3,746 $ 8,402 December 31, 2019 December 31, 2018 Weighted Average Useful Lives Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net (in years) (in millions) CERC Natural Gas Distribution 29 $ 7,933 $ 2,208 $ 5,725 $ 7,257 $ 2,128 $ 5,129 Energy Services (2) 27 136 53 83 121 43 78 Other property 16 55 27 28 53 34 19 Total $ 8,124 $ 2,288 $ 5,836 $ 7,431 $ 2,205 $ 5,226 (1) SIGECO and AGC own a 300 MW unit at the Warrick Power Plant (Warrick Unit 4) as tenants in common. SIGECO’s share of the cost of this unit as of December 31, 2019, is $194 million with accumulated depreciation totaling $137 million . AGC and SIGECO share equally in the cost of operation and output of the unit. SIGECO’s share of operating costs is included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income. (2) On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. (3) On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. (b) Depreciation and Amortization The following table presents depreciation and amortization expense for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Depreciation $ 920 $ 339 $ 281 $ 626 $ 342 $ 264 $ 619 $ 354 $ 243 Amortization of securitized regulatory assets 271 271 — 531 531 — 329 329 — Other amortization 96 38 24 86 44 29 88 41 36 Total $ 1,287 $ 648 $ 305 $ 1,243 $ 917 $ 293 $ 1,036 $ 724 $ 279 (c) AROs The Registrants recorded AROs associated with the removal of asbestos and asbestos-containing material in its buildings, including substation building structures. CenterPoint Energy recorded AROs relating to the closure of the ash ponds at A.B. Brown and F.B. Culley. CenterPoint Energy and Houston Electric also recorded AROs relating to treated wood poles for electric distribution, distribution transformers containing PCB (also known as Polychlorinated Biphenyl), and underground fuel storage tanks. CenterPoint Energy and CERC also recorded AROs relating to gas pipelines abandoned in place. The estimates of future liabilities were developed using historical information, and where available, quoted prices from outside contractors. A reconciliation of the changes in the ARO liability recorded in Other non-current liabilities on each of the Registrants’ respective Consolidated Balance Sheets is as follows: December 31, 2019 December 31, 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Beginning balance $ 258 $ 34 $ 221 $ 281 $ 35 $ 243 Addition from Merger with Vectren 116 — — — — — Accretion expense (1) 16 1 10 10 1 9 Revisions in estimates (2) 149 7 94 (33 ) (2 ) (31 ) Ending balance $ 539 $ 42 $ 325 $ 258 $ 34 $ 221 (1) Reflected in Regulatory assets on each of the Registrants’ respective Consolidated Balance Sheets. (2)

Mergers and Acquisitions

Mergers and Acquisitions	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Mergers and Acquisitions [Text Block]	Mergers and Acquisitions (CenterPoint Energy) Merger with Vectren. On the Merger Date, pursuant to the Merger Agreement, CenterPoint Energy consummated the previously announced Merger and acquired Vectren for approximately $6 billion in cash. Each share of Vectren common stock issued and outstanding immediately prior to the closing was canceled and converted into the right to receive $72.00 in cash per share, without interest. At the closing, each stock unit payable in Vectren common stock or whose value is determined with reference to the value of Vectren common stock, whether vested or unvested, was canceled with cash consideration paid in accordance with the terms of the Merger Agreement. These amounts did not include a stub period cash dividend of $0.41145 per share, which was declared, with CenterPoint Energy’s consent, by Vectren’s board of directors on January 16, 2019, and paid to Vectren stockholders as of the record date of February 1, 2019. Pursuant to the Merger Agreement and immediately subsequent to the close of the Merger, CenterPoint Energy cash settled $78 million in outstanding share-based awards issued prior to the Merger Date by Vectren to its employees. As a result of the Merger, CenterPoint Energy assumed a liability for these share-based awards of $41 million and recorded an incremental cost of $37 million in Operation and maintenance expenses on its Statements of Consolidated Income during the year ended December 31, 2019 for the accelerated vesting of the awards in accordance with the Merger Agreement. Subsequent to the close of the Merger, CenterPoint Energy recognized severance totaling $61 million to employees terminated immediately subsequent to the Merger close, inclusive of change of control severance payments to executives of Vectren under existing agreements, and which is included in Operation and maintenance expenses on its Statements of Consolidated Income during the year ended December 31, 2019 . Total severance cost for the year ended December 31, 2019 was $102 million . In connection with the Merger, VUHI and VCC made offers to prepay certain outstanding guaranteed senior notes as required pursuant to certain note purchase agreements previously entered into by VUHI and VCC. See Note 14 for further details. Following the closing, shares of Vectren common stock, which previously traded under the ticker symbol “VVC” on the NYSE, ceased trading on and were delisted from the NYSE. The Merger is being accounted for in accordance with ASC 805, Business Combinations, with CenterPoint Energy as the accounting acquirer of Vectren. Identifiable assets acquired and liabilities assumed have been recorded at their estimated fair values on the Merger Date. Vectren’s regulated operations, comprised of electric generation and electric and natural gas energy delivery services, are subject to the rate-setting authority of the FERC, the IURC and the PUCO, and are accounted for pursuant to U.S. generally accepted accounting principles for regulated operations. The rate-setting and cost-recovery provisions currently in place for Vectren’s regulated operations provide revenues derived from costs including a return on investment of assets and liabilities included in rate base. Thus, the fair value of Vectren’s tangible and intangible assets and liabilities subject to these rate-setting provisions approximate their carrying values on the Merger Date. The fair value of regulatory assets not earning a return have been determined using the income approach and are considered Level 3 fair value measurements due to the use of significant judgmental and unobservable inputs. The fair value of Vectren’s assets acquired and liabilities assumed that are not subject to the rate-setting provisions, including identifiable intangibles, have been determined using the income approach and the market approach. The valuation of Vectren’s long-term debt is primarily considered a Level 2 fair value measurement. All other valuations are considered Level 3 fair value measurements due to the use of significant judgmental and unobservable inputs, including projected timing and amount of future cash flows and discount rates reflecting risk inherent in the future market prices. The following table presents the purchase price allocation as of December 31, 2019 (in millions): Cash and cash equivalents $ 16 Other current assets 577 Property, plant and equipment, net 5,147 Identifiable intangibles 297 Regulatory assets 338 Other assets 141 Total assets acquired 6,516 Current liabilities 648 Regulatory liabilities 938 Other liabilities 886 Long-term debt 2,401 Total liabilities assumed 4,873 Net assets acquired 1,643 Goodwill 4,339 Total purchase price consideration $ 5,982 CenterPoint Energy completed a final valuation analysis necessary to determine the fair market values of all of Vectren’s assets and liabilities and the allocation of its purchase price. Changes from the preliminary purchase price allocation originally reported in the first quarter of 2019 primarily included additional information obtained related to intangible assets and the allocation of the fair value between reporting units. The excess of the purchase price over the estimated fair values of the assets acquired and liabilities assumed is recognized as goodwill, which is primarily attributable to significant potential strategic benefits to CenterPoint Energy, including growth opportunities for more rate-regulated investment, more customers for existing products and services and additional products and services for existing customers. Additionally, CenterPoint Energy believes the Merger will increase geographic and business diversity as well as scale in attractive jurisdictions and economies. The value assigned to goodwill will not be deductible for tax purposes. The fair value of the identifiable intangible assets and related useful lives as included in the purchase price allocation as of December 31, 2019 include: Weighted Average Useful Lives Estimated Fair Value (in years) (in millions) Operation and maintenance agreements 24 $ 12 Customer relationships 18 200 Construction backlog 1 27 Trade names 10 58 Total $ 297 Amortization expense related to the operation and maintenance agreements and construction backlog was $24 million in 2019 , and is included in Non-utility cost of revenues, including natural gas on CenterPoint Energy’s Statements of Consolidated Income. Amortization expense related to customer relationships and trade names was $16 million in 2019 and is included in Depreciation and amortization expense on CenterPoint Energy’s Statements of Consolidated Income. The results of operations for Vectren included in CenterPoint Energy’s Consolidated Financial Statements from the Merger Date for the year ended December 31, 2019 are as follows: (in millions) Operating revenues $ 2,729 Net income 190 The following unaudited pro forma financial information reflects the consolidated results of operations of CenterPoint Energy, assuming the Merger had taken place on January 1, 2018. The unaudited pro forma financial information has been presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved had the Merger taken place on the dates indicated or of the future consolidated results of operations of the combined company. Year Ended December 31, 2019 2018 (in millions) Operating revenues $ 12,547 $ 13,282 Net income 812 (1) 458 (2) (1) Pro forma net income was adjusted to exclude $37 million of Vectren Merger-related transaction costs incurred in 2019. (2) Pro forma net income was adjusted to include $37 million of Vectren Merger-related transaction costs incurred in 2019 . CenterPoint Energy incurred integration costs in connection with the Merger of $83 million for the year ended December 31, 2019 , which were included in Operation and maintenance expenses in CenterPoint Energy’s Statements of Consolidated Income. Acquisition of Utility Pipeline Construction Company. An acquisition was made during the year ended December 31, 2019 by CenterPoint Energy’s Infrastructure Services reportable segment, resulting in goodwill and intangible assets of approximately $6 million and $8 million , respectively. The intangible assets primarily relate to backlog and customer relationships. The allocation of the $25 million purchase price has been finalized. The results of operations for the acquired company have been included in CenterPoint Energy’s consolidated financial statements from the date of acquisition and are not significant to the consolidated financial results of CenterPoint Energy. Pro forma results of operations have not been presented for the acquisition because the effects of the acquisition were not significant to CenterPoint Energy’s consolidated financial results for all periods presented.

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue Recognition [Text Block]	Revenue Recognition The Registrants adopted ASC 606, Revenue from Contracts with Customers, and all related amendments on January 1, 2018 using the modified retrospective method for those contracts that were not completed as of the date of adoption. Application of the new revenue standard did not result in a cumulative effect adjustment to the opening balance of retained earnings. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The adoption of the new standard did not have a material impact on the Registrants’ financial position, results of operations or cash flows. In accordance with ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration to which the Registrants expect to be entitled to receive in exchange for these goods or services. The following tables disaggregate revenues by reportable segment and major source: CenterPoint Energy Year Ended December 31, 2019 Houston Electric T&D (1) Indiana Electric Integrated (1) (4) Natural Gas Distribution (1) (4) Energy Services (2) Infrastructure Services (2) (4) Corporate and Other (2) (4) Total (in millions) Revenue from contracts $ 2,984 $ 523 $ 3,680 $ 479 $ 1,190 $ 295 $ 9,151 Derivatives income 6 — 2 3,303 — — 3,311 Other (3) 6 — 1 — — 5 12 Eliminations — — (40 ) (129 ) (4 ) — (173 ) Total revenues $ 2,996 $ 523 $ 3,643 $ 3,653 $ 1,186 $ 300 $ 12,301 Year Ended December 31, 2018 Houston Electric T&D (1) Indiana Electric Integrated (1) Natural Gas Distribution (1) Energy Services (2) Infrastructure Services (2) Corporate and Other (2) Total (in millions) Revenue from contracts $ 3,235 $ — $ 3,011 $ 493 $ — $ 6 $ 6,745 Derivatives income (2 ) — (2 ) 4,028 — — 4,024 Other (3) (1 ) — (42 ) — — 9 (34 ) Eliminations — — (36 ) (110 ) — — (146 ) Total revenues $ 3,232 $ — $ 2,931 $ 4,411 $ — $ 15 $ 10,589 Year Ended December 31, 2017 Houston Electric T&D (1) Indiana Electric Integrated (1) Natural Gas Distribution (1) Energy Services (2) Infrastructure Services (2) Corporate and Other (2) Total (in millions) Revenue from contracts $ 3,001 $ — $ 2,638 $ 480 $ — $ 5 $ 6,124 Derivatives income (1 ) — — 3,569 — — 3,568 Other (3) (3 ) — 1 — — 9 7 Eliminations — — (33 ) (52 ) — — (85 ) Total revenues $ 2,997 $ — $ 2,606 $ 3,997 $ — $ 14 $ 9,614 (1) Reflected in Utility revenues in the Statements of Consolidated Income. (2) Reflected in Non-utility revenues in the Statements of Consolidated Income. (3) Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period. (4) Reflects revenues from Vectren subsidiaries for the period from February 1, 2019 to December 31, 2019. Houston Electric Year Ended December 31, 2019 2018 2017 (in millions) Revenue from contracts $ 2,984 $ 3,235 $ 3,001 Other (1) 6 (1 ) (3 ) Total revenues $ 2,990 $ 3,234 $ 2,998 (1) Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period. CERC Year Ended December 31, 2019 Natural Gas Distribution (1) Energy Services (2) Corporate and Other (2) Total (in millions) Revenue from contracts $ 2,945 $ 480 $ 5 $ 3,430 Derivatives income 2 3,302 — 3,304 Other (3) 4 — — 4 Eliminations (40 ) (128 ) — (168 ) Total revenues $ 2,911 $ 3,654 $ 5 $ 6,570 Year Ended December 31, 2018 Natural Gas Distribution (1) Energy Services (2) Corporate Total (in millions) Revenue from contracts $ 3,011 $ 493 $ 1 $ 3,505 Derivatives income (2 ) 4,028 — 4,026 Other (3) (42 ) — — (42 ) Eliminations (36 ) (110 ) — (146 ) Total revenues $ 2,931 $ 4,411 $ 1 $ 7,343 Year Ended December 31, 2017 Natural Gas Distribution (1) Energy Services (2) Corporate Total (in millions) Revenue from contracts $ 2,638 $ 480 $ — $ 3,118 Derivatives income — 3,569 — 3,569 Other (3) 1 — — 1 Eliminations (33 ) (52 ) — (85 ) Total revenues $ 2,606 $ 3,997 $ — $ 6,603 (1) Reflected in Utility revenues in the Statements of Consolidated Income. (2) Reflected in Non-utility revenues in the Statements of Consolidated Income. (3) Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period. Revenues from Contracts with Customers Houston Electric T&D (CenterPoint Energy and Houston Electric). Houston Electric distributes electricity to customers over time and customers consume the electricity when delivered. Revenue, consisting of both volumetric and fixed tariff rates set by the PUCT, is recognized as electricity is delivered and represents amounts both billed and unbilled. Discretionary services requested by customers are provided at a point in time with control transferring upon the completion of the service. Revenue for discretionary services is recognized upon completion of service based on the tariff rates set by the PUCT. Payments for electricity distribution and discretionary services are aggregated and received on a monthly basis. Houston Electric performs transmission services over time as a stand-ready obligation to provide a reliable network of transmission systems. Revenue is recognized upon time elapsed, and the monthly tariff rate set by the PUCT. Payments are received on a monthly basis. Indiana Electric Integrated (CenterPoint Energy). Indiana Electric generates, distributes and transmits electricity to customers over time, and customers consume the electricity when delivered. Revenue, consisting of both volumetric and fixed tariff rates set by state regulators, is recognized as electricity is delivered and represents amounts both billed and unbilled. Customers are billed monthly and payment terms, set by the regulator, require payment within a month of billing. Natural Gas Distribution (CenterPoint Energy and CERC). CERC distributes and transports natural gas to customers over time, and customers consume the natural gas when delivered. Revenue, consisting of both volumetric and fixed tariff rates set by the state governing agency for that service area, is recognized as natural gas is delivered and represents amounts both billed and unbilled. Discretionary services requested by the customer are satisfied at a point in time and revenue is recognized upon completion of service and the tariff rates set by the applicable state regulator. Payments of natural gas distribution, transportation and discretionary services are aggregated and received on a monthly basis. Energy Services (CenterPoint Energy and CERC). The majority of CES natural gas sales contracts are considered a derivative, as the contracts typically have a stated minimum or contractual volume of delivery. For contracts in which CES delivers the full requirement of the natural gas needed by the customer and a volume is not stated, a contract as defined under ASC 606 is created upon the customer’s exercise of its option to take natural gas. CES supplies natural gas to retail customers over time as customers consume the natural gas when delivered. For wholesale customers, CES supplies natural gas at a point in time because the wholesale customer is presumed to have storage capabilities. Control is transferred to both types of customers upon delivery of natural gas. Revenue is recognized on a monthly basis based on the estimated volume of natural gas delivered and the price agreed upon with the customer. Payments are received on a monthly basis. AMAs are natural gas sales contracts under which CES also assumes management of a customer’s physical storage and/or transportation capacity. AMAs have two distinct performance obligations, which consist of natural gas sales and natural gas delivery because delivery could occur separate from the sale of natural gas (e.g., from storage to customer premises). Most AMAs’ natural gas sales performance obligations are accounted for as embedded derivatives. The transaction price is allocated between the sale of natural gas and the delivery based on the stand-alone selling price as stated in the contract. CES performs natural gas delivery over time as customers take delivery of the natural gas and recognizes revenue on an aggregated monthly basis based on the volume of natural gas delivered and the fees stated within the contract. Payments are received on a monthly basis. On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. Infrastructure Services (CenterPoint Energy). Infrastructure Services provides underground pipeline construction and repair services. The contracts are generally less than one year in duration and consist of fixed price, unit, and time and material customer contracts. Under unit or time and material contracts, Infrastructure Services performs construction and repair services under specific work-orders at prices established by master service agreements. The performance obligation is defined at the work-order level. These services are billed to customers monthly or more frequently for work completed based on units completed or the costs of time and material incurred and generally require payment within 30 days of billing. Infrastructure Services has the right to consideration from customers in an amount that corresponds directly with the performance obligation satisfied, and therefore recognizes revenue at a point in time in the amount to which it has the right to invoice, which results in accrued unbilled revenues at the end of each accounting period. Under fixed price contracts, Infrastructure Services performs larger scale construction and repair services. Each contract is typically accounted for as a single performance obligation. Services performed under fixed price contracts are typically billed per the terms of the contract, which can range from completion of specific milestones to scheduled billing intervals. Billings occur monthly or more frequently for work completed and generally require payment within 30 days of billing. Revenue for fixed price contracts is recognized over time as control is transferred using the input method, considering costs incurred relative to total expected cost. Total expected cost is therefore a significant judgment affecting the amount and timing of revenue recognition. Infrastructure Services’ revenues are not subject to significant returns, refunds or warranty obligations. On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. Contract Balances. When the timing of delivery of service is different from the timing of the payments made by customers and when the right to consideration is conditioned on something other than the passage of time, the Registrants recognize either a contract asset (performance precedes billing) or a contract liability (customer payment precedes performance). Those customers that prepay are represented by contract liabilities until the performance obligations are satisfied. The Registrants’ contract assets are included in Accrued unbilled revenues in their Consolidated Balance Sheets. On an aggregate basis as of December 31, 2019 , the Registrants’ contract assets primarily relate to contracts in the Infrastructure Services segment where revenue is recognized using the input method. The Registrants’ contract liabilities are included in Accounts payable and Other current liabilities in their Consolidated Balance Sheets. On an aggregate basis as of December 31, 2019, the Registrants’ contract liabilities primarily relate to ESG contracts where revenue is recognized using the input method. The opening and closing balances of accounts receivable, other accrued unbilled revenue, contract assets and contract liabilities from contracts with customers for the year ended December 31, 2019 are as follows: CenterPoint Energy Accounts Receivable Other Accrued Unbilled Revenues Contract Assets Contract Liabilities (in millions) Opening balance as of December 31, 2018 (1) $ 516 $ 373 $ — $ 3 Closing balance as of December 31, 2019 800 579 61 34 Increase $ 284 $ 206 $ 61 $ 31 (1) Opening balances related to Vectren are as of February 1, 2019, and are thus excluded from the opening balance as of December 31, 2018. The amount of revenue recognized in the year ended December 31, 2019 that was included in the opening contract liability was $47 million . The difference between the opening and closing balances of the contract liabilities primarily results from the timing difference between CenterPoint Energy’s performance and the customer’s payment, plus the addition of obligations acquired in the Merger. Houston Electric Accounts Receivable Other Accrued Unbilled Revenues Contract Liabilities (in millions) Opening balance as of December 31, 2018 $ 234 $ 110 $ 3 Closing balance as of December 31, 2019 210 117 3 Increase (decrease) $ (24 ) $ 7 $ — The amount of revenue recognized in the year ended December 31, 2019 that was included in the opening contract liability was $3 million . The difference between the opening and closing balances of the contract liabilities primarily results from the timing difference between Houston Electric’s performance and the customer’s payment. CERC Accounts Receivable Other Accrued Unbilled Revenues (in millions) Opening balance as of December 31, 2018 $ 282 $ 263 Closing balance as of December 31, 2019 282 250 Increase (decrease) $ — $ (13 ) CERC does not have any opening or closing contract asset or contract liability balances. Remaining Performance Obligations (CenterPoint Energy). The table below discloses (1) the aggregate amount of the transaction price allocated to performance obligations that are unsatisfied (or partially unsatisfied) as of the end of the reporting period for contracts and (2) when CenterPoint Energy expects to recognize this revenue. Such contracts include fixed price contracts and energy performance and sustainable infrastructure services contracts of ESG, which are included in Corporate and Other. Rolling 12 Months Thereafter Total (in millions) Revenue expected to be recognized on contracts in place as of December 31, 2019: Infrastructure Services $ 254 $ — $ 254 Corporate and Other 84 752 836 $ 338 $ 752 $ 1,090 Practical Expedients and Exemption. Sales taxes and other similar taxes collected from customers are excluded from the transaction price. For contracts for which revenue from the satisfaction of the performance obligations is recognized in the amount invoiced, the practical expedient was elected and revenue expected to be recognized on these contracts has not been disclosed.

Goodwill and Other Intangibles

Goodwill and Other Intangibles (CenterPoint Energy and CERC)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles (CenterPoint Energy and CERC) [Text Block]	Goodwill and Other Intangibles (CenterPoint Energy and CERC) CenterPoint Energy’s goodwill by reportable segment as of December 31, 2018 and changes in the carrying amount of goodwill as of December 31, 2019 are as follows: December 31, 2018 Additions (1) Impairment December 31, (in millions) Indiana Electric Integrated $ — $ 1,121 $ — $ 1,121 Natural Gas Distribution 746 2,566 — 3,312 Energy Services (2) 110 — 48 62 Infrastructure Services — 220 — 220 Corporate and Other 11 438 — 449 Total $ 867 $ 4,345 $ 48 $ 5,164 (1) This represents the allocation of goodwill to reportable segments from the Merger, changes from preliminary amounts previously reported and includes the final determination of fair value for each reportable segment. See Note 4 . (2) Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012. As of December 31, 2019, CenterPoint Energy and CERC identified a triggering event to perform an interim goodwill impairment test and recognized a goodwill impairment on their Energy Services reporting unit which is included in Goodwill impairment on CenterPoint Energy’s and CERC’s Consolidated Statements of Income. CERC’s goodwill by reportable segment as of December 31, 2019 and December 31, 2018 is as follows: December 31, 2018 Impairment December 31, 2019 (in millions) Natural Gas Distribution $ 746 $ — $ 746 Energy Services (1) 110 48 62 Corporate and Other 11 — 11 Total $ 867 $ 48 $ 819 (1) Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012. CenterPoint Energy and CERC perform goodwill impairment tests at least annually and evaluate goodwill when events or changes in circumstances indicate that its carrying value may not be recoverable. The impairment evaluation for goodwill is performed by comparing the fair value of each reporting unit with the carrying amount of the reporting unit, including goodwill. The reporting units approximate the reportable segments, with the exception of ESG, which is a separate reporting unit but included in CenterPoint Energy’s Corporate and Other reportable segment. The estimated fair value of a reporting unit is primarily determined based on an income approach or a weighted combination of income and market approaches. If the carrying amount of the reporting unit is in excess of the estimated fair value of the reporting unit, then the excess amount is the impairment charge that should be recorded, not to exceed the carrying amount of goodwill. See Note 2(g) for further discussion. CenterPoint Energy and CERC performed the annual goodwill impairment test on July 1 of each of 2019 and 2018 and determined that no goodwill impairment charge was required for any reporting unit in its annual test. In connection with its preparation of financial statements for the year ended December 31, 2019, CenterPoint Energy and CERC, as applicable, identified triggering events for interim goodwill impairment tests at the Infrastructure Services and Energy Services reporting units. Early stage bids received from market participants during the exploration of strategic alternatives for these businesses at year-end indicated that the fair value of each reporting unit was more likely than not below the carrying value. On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reporting unit. Per the Securities Purchase Agreement, VISCO will be converted from a wholly-owned corporation to a limited liability company that is disregarded for federal income tax purposes immediately prior to the closing of the transaction resulting in the sale of membership units at closing. The sale will be considered an asset sale for tax purposes requiring the net deferred tax liabilities of approximately $123 million within the reporting unit as of December 31, 2019 to be recognized as a benefit to deferred income tax expense by CenterPoint Energy upon closing; therefore, any deferred tax assets and liabilities within the reporting unit are not included in the carrying amount of the assets and liabilities that will be transferred to the buyer. For further information, see Note 23. On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reporting unit. Per the Equity Purchase Agreement, CES will be converted from a wholly-owned corporation to a limited liability company that is disregarded for federal income tax purposes immediately prior to the closing of the transaction resulting in the sale of membership units at closing. For further information, see Note 23. The fair value of the Infrastructure Services reporting unit was estimated using a market approach deriving an estimated fair value as of December 31, 2019 based on the economic terms agreed upon within the Securities Purchase Agreement, a Level 2 fair value measurement. As of December 31, 2019 the fair value of the Infrastructure Services reporting unit exceeded the carrying value (inclusive of deferred income tax liabilities of $123 million ) and no impairment loss was recognized. The fair value of the Energy Services reporting unit was estimated using a combination of the market approach and the income approach as of December 31, 2019, a Level 3 fair value measurement. CenterPoint Energy and CERC utilized the economic indicators of value received by market participants during the exploration of strategic alternatives to inform the fair value of substantially all of the businesses within this reporting unit as of December 31, 2019. Certain assets groups not constituting a business within the reporting unit were valued using an income approach. CenterPoint Energy and CERC recognized an impairment loss on their Energy Services reporting unit of $48 million , the amount by which the carrying value (inclusive of deferred income tax liabilities of $25 million ) exceeded the fair value as of December 31, 2019. The tables below present information on CenterPoint Energy’s other intangible assets recorded in Intangible assets, net on the Consolidated Balance Sheets and the related amortization expense included in Depreciation and amortization on CenterPoint Energy’s Statements of Consolidated Income, unless otherwise indicated. December 31, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Balance Gross Carrying Amount Accumulated Amortization Net Balance (in millions) Customer relationships (1) $ 286 $ (43 ) $ 243 $ 86 $ (27 ) $ 59 Covenants not to compete 4 (4 ) — 4 (3 ) 1 Trade names (1) 58 (5 ) 53 — — — Construction backlog (1) (2) 27 (23 ) 4 — — — Operation and maintenance agreements (1) (2) 12 (1 ) 11 — — — Other (1) 24 (14 ) 10 16 (11 ) 5 Total $ 411 $ (90 ) $ 321 $ 106 $ (41 ) $ 65 (1) The fair value of intangible assets acquired through acquisitions has been finalized. See Note 4 . (2) Amortization expense related to the operation and maintenance agreements and construction backlog is included in Non-utility cost of revenues, including natural gas on CenterPoint Energy’s Statements of Consolidated Income. Year Ended December 31, 2019 2018 2017 (in millions) Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2) $ 25 $ 10 $ 13 Amortization expense of intangible assets recorded in (2) 24 — — (1) Includes $17 million for the year ended December 31, 2019 of amortization expense related to intangibles acquired in the Merger. (2) The fair value of intangible assets, and related amortization assumptions, acquired through acquisitions during the year ended December 31, 2019 , has been finalized. See Note 4 . The tables below present information on CERC’s other intangible assets recorded in Other non-current assets on CERC’s Consolidated Balance Sheets and the related amortization expense included in Depreciation and amortization on CERC’s Statements of Consolidated Income. December 31, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Balance Gross Carrying Amount Accumulated Amortization Net Balance (in millions) Customer relationships $ 86 $ (32 ) $ 54 $ 86 $ (27 ) $ 59 Covenants not to compete 4 (4 ) — 4 (3 ) 1 Other 16 (14 ) 2 16 (11 ) 5 Total $ 106 $ (50 ) $ 56 $ 106 $ (41 ) $ 65 Year Ended December 31, 2019 2018 2017 (in millions) Amortization expense of intangible assets recorded in Depreciation and amortization $ 9 $ 10 $ 13 CenterPoint Energy and CERC estimate that amortization expense of intangible assets with finite lives for the next five years will be as follows: Amortization Expense CenterPoint Energy CERC (in millions) 2020 $ 29 $ 6 2021 25 6 2022 25 6 2023 24 5 2024 22 5

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2019
Regulated Operations [Abstract]
Regulatory Accounting [Text Block]	Regulatory Matters The following is a list of regulatory assets and liabilities reflected on the Registrants’ respective Consolidated Balance Sheets as of December 31, 2019 and 2018 . The “amortization through” columns indicate the latest year when a regulatory asset or regulatory liability category will be fully amortized: December 31, 2019 CenterPoint Energy Houston Electric CERC Amortization Through (in millions) Amortization Through (in millions) Amortization Through (in millions) Regulatory Assets: Current regulatory assets (1) 2020 $ 12 n/a $ — 2020 $ 12 Non-current regulatory assets: Securitized regulatory assets 2024 788 2024 788 n/a — Unrecognized equity return (2) 2024 (168 ) 2024 (168 ) n/a — Unamortized loss on reacquired debt (3) 2046 62 2046 62 n/a — Pension and postretirement-related regulatory asset (3) Various (a) 637 TBD (b) 34 Various (a) 22 Hurricane Harvey restoration costs (3) Various 68 TBD (b) 64 TBD (c) 4 Regulatory assets related to TCJA (3) (4) Various 30 TBD (b) 23 2023 7 Asset retirement obligation (3) Perpetual 131 Perpetual 26 Perpetual 94 Other regulatory assets-not earning a return (5) Various (d) 147 Various 57 Various 48 Other regulatory assets Various 422 Various 29 Various 16 Total non-current regulatory assets 2,117 915 191 Total regulatory assets 2,129 915 203 Regulatory Liabilities: Current regulatory liabilities (6) 2020 47 n/a — 2020 47 Non-current regulatory liabilities: Regulatory liabilities related to TCJA (4) Various 1,582 TBD (b) 821 Various 442 Estimated removal costs Various 1,429 Various 244 Various 637 Other regulatory liabilities Various 463 Various 223 Various 140 Total non-current regulatory liabilities 3,474 1,288 1,219 Total regulatory liabilities 3,521 1,288 1,266 Total regulatory assets and liabilities, net $ (1,392 ) $ (373 ) $ (1,063 ) (a) Pension and postretirement-related regulatory assets balances are measured annually, and the ending amortization period may change based on the actuarial valuation. (b) The recovery and amortization of these amounts are to be determined upon receipt of the final order. (c) The recovery and amortization of a portion of these amounts are expected to be determined in the next rate case. (d) Other regulatory assets not-earning a return includes items with different amortization periods; therefore, the amortization is accounted for through various periods. December 31, 2018 CenterPoint Energy Houston Electric CERC (in millions) Regulatory Assets: Current regulatory assets (1) $ 77 $ — $ 77 Non-current regulatory assets: Securitized regulatory assets 1,059 1,059 — Unrecognized equity return (2) (213 ) (213 ) — Unamortized loss on reacquired debt (3) 68 68 — Pension and postretirement-related regulatory asset (3) 725 33 30 Hurricane Harvey restoration costs (3) 68 64 4 Regulatory assets related to TCJA (3) (4) 33 23 10 Asset retirement obligation (3) 109 24 85 Other regulatory assets-not earning a return (3) 81 55 26 Other regulatory assets 37 11 26 Total non-current regulatory assets 1,967 1,124 181 Total regulatory assets 2,044 1,124 258 Regulatory Liabilities: Current regulatory liabilities (6) 38 17 21 Non-current regulatory liabilities: Regulatory liabilities related to TCJA (4) 1,323 847 476 Estimated removal costs 886 269 617 Other regulatory liabilities 316 182 134 Total non-current regulatory liabilities 2,525 1,298 1,227 Total regulatory liabilities 2,563 1,315 1,248 Total regulatory assets and liabilities, net $ (519 ) $ (191 ) $ (990 ) (1) Current regulatory assets are included in Prepaid expenses and other current assets in the Registrants’ respective Consolidated Balance Sheets. (2) The unrecognized equity return will be recognized as it is recovered in rates through 2024. The timing of CenterPoint Energy’s and Houston Electric’s recognition of the equity return will vary each period based on amounts actually collected during the period. The actual amounts recognized are adjusted at least annually to correct any over-collections or under-collections during the preceding 12 months. Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CenterPoint Energy Houston Electric CenterPoint Energy Houston Electric Allowed equity return recognized $ 45 $ 45 $ 74 $ 74 $ 42 $ 42 (3) Substantially all of these regulatory assets are not earning a return. (4) The EDIT and deferred revenues will be recovered or refunded to customers as required by tax and regulatory authorities. See Note 15 for additional information. (5) Regulatory assets acquired in the Merger and not earning a return were recorded at fair value as of the Merger Date. Such fair value adjustments are recognized over time until the regulatory asset is recovered. (6) Current regulatory liabilities are included in Other current liabilities in each of the Registrants’ respective Consolidated Balance Sheets. Houston Electric Base Rate Case (CenterPoint Energy and Houston Electric) On April 5, 2019, and subsequently adjusted in errata filings in May and June 2019, Houston Electric filed its base rate application with the PUCT and the cities in its service area seeking approval for revenue increases of approximately $194 million , exclusive of the EDIT refund discussed below. The key proposals of the base rate case included: • a rate base of $6.4 billion with a 50% debt/ 50% equity capital structure and a 10.4% ROE; • a prudency determination on all capital investments made by Houston Electric since January 1, 2010; • the establishment of a rider to refund unprotected EDIT resulting from the TCJA; and • updated depreciation rates and approval to recover other costs. On September 16, 2019, the ALJs issued a PFD. The PUCT began deliberating on the PFD (which is prepared by ALJs at a different state agency) during its November 14, 2019 open meeting, but delayed final determination for further consideration. The PUCT again discussed the Houston Electric rate case at its December 13, 2019 open meeting and concluded that the PUCT would consider settlement a reasonable approach to resolving the rate case and noted that Houston Electric had indicated settlement negotiations were already underway. Houston Electric updated the PUCT at its January 16, 2020 open meeting regarding the status of settlement discussions, indicating that the parties were working on a settlement and anticipated a final settlement in the near future. On January 23, 2020, Houston Electric filed a Stipulation and Settlement Agreement with the PUCT, which provides for the following, among other things: • an overall revenue requirement increase of approximately $13 million ; • an ROE of 9.4% ; • a capital structure of 57.5% debt/ 42.5% equity; • a refund of unprotected EDIT of $105 million plus carrying costs over approximately 30-36 months; and • recovery of all retail transmission related costs through the TCRF. Also, Houston Electric is not required to make a one-time refund of capital recovery from its TCOS and DCRF mechanisms. Future TCOS filings will take into account both ADFIT and EDIT until the final order from Houston Electric’s next base rate proceeding. No rate base items are expected to be written off; however, approximately $12 million in rate case expenses were written off in 2019. A base rate case application must be filed for Houston Electric no later than four years from the date of the PUCT’s final order in the proceeding. Additionally, Houston Electric will not file a DCRF in 2020, nor will a subsequent separate proceeding with the PUCT be instituted regarding EDIT on Houston Electric’s securitized assets. Furthermore, under the terms of the Stipulation and Settlement Agreement, Houston Electric agreed to adopt certain ring-fencing measures to increase its financial separateness from CenterPoint Energy, which include the following: • Houston Electric’s credit agreements and indentures shall not contain cross-default provisions by which a default by CenterPoint Energy or its other affiliates would cause a default at Houston Electric; • The financial covenant in Houston Electric’s credit agreement shall not be related to any entity other than Houston Electric. Houston Electric shall not include in its debt or credit agreements any financial covenants or rating agency triggers related to any entity other than Houston Electric; • Houston Electric shall not pledge its assets in respect of or guarantee any debt or obligation of any of its affiliates. Houston Electric shall not pledge, mortgage, hypothecate, or grant a lien upon the property of Houston Electric except pursuant to an exception in effect in Houston Electric’s current credit agreement, such as Houston Electric’s first mortgage and general mortgage; • Houston Electric shall maintain its own stand-alone credit facility, and Houston Electric shall not share its credit facility with any regulated or unregulated affiliate; • Houston Electric shall maintain ratings with all three major credit ratings agencies; • Houston Electric shall maintain a stand-alone credit rating; • Houston Electric’s first mortgage bonds and general mortgage bonds shall be secured only with assets of Houston Electric; • No Houston Electric assets may be used to secure the debt of CenterPoint Energy or its other affiliates; • Houston Electric shall not hold out its credit as being available to pay the debt of any affiliates (provided that, for the avoidance of doubt, Houston Electric is not considered to be holding its credit out to pay the debt of affiliates, or in breach of any other ring-fencing measure, with respect to the $68 million of Houston Electric general mortgage bonds that currently serve as collateral for certain outstanding CenterPoint Energy pollution control bonds); • Without prior approval of the PUCT, neither CenterPoint Energy nor any affiliate of CenterPoint Energy (excluding Houston Electric) may incur, guarantee, or pledge assets in respect of any incremental new debt that is dependent on: (1) the revenues of Houston Electric in more than a proportionate degree than the other revenues of CenterPoint Energy; or (2) the equity of Houston Electric; • Houston Electric shall not transfer any material assets or facilities to any affiliates, other than a transfer that is on an arm’s length basis consistent with the PUCT’s affiliate standards applicable to Houston Electric; • Except for its participation in an affiliate money pool, Houston Electric shall not commingle its assets with those of other CenterPoint Energy affiliates; • Except for its participation in an affiliate money pool, Houston Electric shall not lend money to or borrow money from CenterPoint Energy; and • Houston Electric shall notify the PUCT if its issuer credit rating or corporate credit rating as rated by any of the three major rating agencies falls below investment grade. The PUCT approved the settlement at its February 14, 2020 open meeting. A final order from the PUCT is currently expected during the first quarter of 2020; however, motions for rehearing, if granted, could result in the order being issued after the first quarter of 2020. The rates are expected to be implemented 45 days after the final order is issued.

Stock-Based Incentive Compensat

Stock-Based Incentive Compensation Plans and Employee Benefit Plans	12 Months Ended
	Dec. 31, 2019
Disclosure of Stock-Based Incentive Compensation Plans and Employee Benefit Plans [Abstract]
Stock-Based Incentive Compensation Plans and Employee Benefit Plans [Text Block]	Stock-Based Incentive Compensation Plans and Employee Benefit Plans (a) Stock-Based Incentive Compensation Plans (CenterPoint Energy) CenterPoint Energy has LTIPs that provide for the issuance of stock-based incentives, including stock options, performance awards, restricted stock unit awards and restricted and unrestricted stock awards to officers, employees and non-employee directors. Approximately 14 million shares of Common Stock are authorized under these plans for awards. CenterPoint Energy issues new shares of its Common Stock to satisfy stock-based payments related to LTIPs. Equity awards are granted to employees without cost to the participants. Compensation costs for the performance and stock unit awards granted under LTIPs are measured using fair value and expected achievement levels on the grant date. For performance awards with operational goals, the achievement levels are revised as goals are evaluated. The fair value of awards granted to employees is based on the closing stock price of CenterPoint Energy’s Common Stock on the grant date. The compensation expense is recorded on a straight-line basis over the vesting period. Forfeitures are estimated on the date of grant based on historical averages and estimates are updated periodically throughout the vesting period. The performance awards granted in 2019 , 2018 and 2017 are distributed based upon the achievement of certain objectives over a three-year performance cycle. The stock unit awards granted in 2019 , 2018 and 2017 are service based. The stock unit awards generally vest at the end of a three-year period, provided, however, that stock unit awards granted to non-employee directors vested at the end of a one-year period (for awards granted in 2017) or vested immediately upon grant (for awards granted in 2019 and 2018). Upon vesting, both the performance and stock unit awards are issued to the participants along with the value of dividend equivalents earned over the performance cycle or vesting period. The following table summarizes CenterPoint Energy’s expenses related to LTIPs for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 (in millions) LTIP Compensation expense (1) $ 28 $ 26 $ 21 Income tax benefit recognized 7 6 8 Actual tax benefit realized for tax deductions 12 5 6 (1) Amounts presented in the table above are included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income and shown prior to any amounts capitalized. The following tables summarize CenterPoint Energy’s LTIP activity for 2019 : Year Ended December 31, 2019 Shares (Thousands) Weighted-Average Grant Date Fair Value Remaining Average Contractual Life (Years) Aggregate Intrinsic Value (2) (Millions) Performance Awards (1) Outstanding and non-vested as of December 31, 2018 3,818 $ 23.91 Granted 1,413 31.16 Forfeited or canceled (825 ) 24.78 Vested and released to participants (1,074 ) 18.97 Outstanding and non-vested as of December 31, 2019 3,332 $ 28.36 1.1 $ 53 Stock Unit Awards Outstanding and non-vested as of December 31, 2018 1,060 $ 24.08 Granted 470 31.07 Forfeited or canceled (131 ) 27.95 Vested and released to participants (433 ) 20.72 Outstanding and non-vested as of December 31, 2019 966 $ 28.46 1.2 $ 26 (1) Reflects maximum performance achievement. (2) Reflects the impact of current expectations of achievement and stock price. The weighted average grant date fair values per unit of awards granted were as follows for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 (In millions, except for per unit amounts) Performance Awards Weighted-average grant date fair value per unit of awards granted $ 31.16 $ 26.74 $ 26.64 Total intrinsic value of awards received by participants 36 12 7 Vested grant date fair value 20 9 5 Stock Unit Awards Weighted-average grant date fair value per unit of awards granted $ 31.07 $ 26.62 $ 26.77 Total intrinsic value of awards received by participants 15 9 9 Vested grant date fair value 9 7 7 As of December 31, 2019 , there was $34 million of total unrecognized compensation cost related to non-vested performance and stock awards which is expected to be recognized over a weighted-average period of 1.7 years. (b) Pension Benefits (CenterPoint Energy) CenterPoint Energy maintains a non-contributory qualified defined benefit pension plan covering eligible employees, with benefits determined using a cash balance formula. In addition to the non-contributory qualified defined benefit pension plan, CenterPoint Energy maintains unfunded non-qualified benefit restoration plans which allow participants to receive the benefits to which they would have been entitled under CenterPoint Energy’s non-contributory qualified pension plan except for federally mandated limits on qualified plan benefits or on the level of compensation on which qualified plan benefits may be calculated. As a result of the Merger, CenterPoint Energy now also maintains three additional qualified defined benefit pension plans which are closed to new participants and a non-qualified supplemental retirement plan. The defined benefit pension plans cover eligible full-time regular employees and retirees of Vectren and are primarily non-contributory. CenterPoint Energy’s net periodic cost includes the following components relating to pension, including the non-qualified benefit plans: Year Ended December 31, 2019 2018 2017 (in millions) Service cost (1) $ 40 $ 37 $ 36 Interest cost (2) 96 79 89 Expected return on plan assets (2) (105 ) (107 ) (97 ) Amortization of prior service cost (2) 9 9 9 Amortization of net loss (2) 52 43 58 Settlement cost (2) (3) 2 — — Curtailment gain (2) (4) (1 ) — — Net periodic cost $ 93 $ 61 $ 95 (1) Amounts presented in the table above are included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income, net of regulatory deferrals and amounts capitalized. (2) Amounts presented in the table above are included in Other, net in CenterPoint Energy’s Statements of Consolidated Income, net of regulatory deferrals. (3) A one-time, non-cash settlement cost is required when the total lump sum distributions or other settlements of plan benefit obligations during a plan year exceed the service cost and interest cost components of the net periodic cost for that year. In 2019, CenterPoint Energy recognized a non-cash settlement cost due to lump sum settlement payments. (4) A curtailment gain or loss is required when the expected future services of a significant number of employees are reduced or eliminated for the accrual of benefits. In 2019, CenterPoint Energy recognized a pension curtailment gain related to employees who were terminated after the Merger closed. CenterPoint Energy used the following assumptions to determine net periodic cost relating to pension benefits: Year Ended December 31, 2019 2018 2017 Discount rate 4.35 % 3.65 % 4.15 % Expected return on plan assets 6.00 6.00 6.00 Rate of increase in compensation levels 4.60 4.45 4.50 In determining net periodic benefit cost, CenterPoint Energy uses fair value, as of the beginning of the year, as its basis for determining expected return on plan assets. The following table summarizes changes in the benefit obligation, plan assets, the amounts recognized in the Consolidated Balance Sheets as well as the key assumptions of CenterPoint Energy’s pension plans. The measurement dates for plan assets and obligations were December 31, 2019 and 2018 . December 31, 2019 2018 (in millions, except for actuarial assumptions) Change in Benefit Obligation Benefit obligation, beginning of year $ 2,013 $ 2,225 Plan obligations assumed in Merger 332 — Service cost 40 37 Interest cost 96 79 Benefits paid (244 ) (201 ) Actuarial (gain) loss (1) 216 (127 ) Plan amendment 1 — Curtailment (1 ) — Benefit obligation, end of year 2,453 2,013 Change in Plan Assets Fair value of plan assets, beginning of year 1,516 1,801 Plan assets assumed in Merger 286 — Employer contributions 109 69 Benefits paid (244 ) (201 ) Actual investment return 338 (153 ) Fair value of plan assets, end of year 2,005 1,516 Funded status, end of year $ (448 ) $ (497 ) Amounts Recognized in Balance Sheets Current liabilities-other $ (8 ) $ (7 ) Other liabilities-benefit obligations (440 ) (490 ) Net liability, end of year $ (448 ) $ (497 ) Actuarial Assumptions Discount rate (2) 3.20 % 4.35 % Expected return on plan assets (3) 5.75 6.00 Rate of increase in compensation levels 4.95 4.60 Interest crediting rate 3.25 3.75 (1) Significant sources of loss for 2019 include the decrease in discount rate from 4.35% to 3.20% . Significant sources of gain for 2018 include the increase in discount rate from 3.65% to 4.35% and the mortality projection scale change from MP2017 to MP2018. (2) The discount rate assumption was determined by matching the projected cash flows of CenterPoint Energy’s plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years. (3) The expected rate of return assumption was developed using the targeted asset allocation of CenterPoint Energy’s plans and the expected return for each asset class. The following table displays pension benefits related to CenterPoint Energy’s pension plans that have accumulated benefit obligations in excess of plan assets: December 31, 2019 2018 Pension (Qualified) Pension (Non-qualified) Pension Pension (in millions) Accumulated benefit obligation $ 2,352 $ 68 $ 1,930 $ 61 Projected benefit obligation 2,385 68 1,952 61 Fair value of plan assets 2,005 — 1,516 — The accumulated benefit obligation for all defined benefit pension plans on CenterPoint Energy’s Consolidated Balance Sheets was $2,420 million and $1,991 million as of December 31, 2019 and 2018 , respectively. Multi-employer Pension Plan CenterPoint Energy, through its Infrastructure Services reportable segment, participates in several industry wide multi-employer pension plans for its collective bargaining employees which provide for monthly benefits based on length of service. The risks of participating in multi-employer pension plans are different from the risks of participating in single-employer pension plans in the following respects: (1) assets contributed to the multi-employer plan by one employer may be used to provide benefits to employees of other participating employers, (2) if a participating employer stops contributing to the plan, the unfunded obligations of the plan allocable to such withdrawing employer may be borne by the remaining participating employers and (3) if CenterPoint Energy stops participation in some of its multi-employer pension plans, CenterPoint Energy may be required to pay those plans an amount based on its allocable share of the underfunded status of the plan, referred to as a withdrawal liability. Expense is recognized as payments are accrued for work performed or when withdrawal liabilities are probable and estimable. Expense associated with multi-employer plans of $52 million during the year ended December 31, 2019 . During 2019 , CenterPoint Energy made contributions to these multi-employer plans on behalf of employees that participate in approximately 215 local unions. Contracts with these unions are negotiated with trade agreements through two primary contractor associations. These trade agreements have varying expiration dates ranging from 2020 through 2022. The average contribution related to these local unions was less than $1 million , and the largest contribution was approximately $5 million . Multiple unions can contribute to a single multi-employer plan. CenterPoint Energy made contributions to at least 72 plans in 2019, eight of which are considered significant plans based on, among other things, the amount of the contributions, the number of employees participating in the plan, and the funded status of the plan. CenterPoint Energy’s participation in the significant plans is outlined in the following table. The EIN / Pension Plan Number column provides the EIN and three-digit pension plan numbers. The most recent Pension Protection Act Zone Status available in 2019 is for the plan year end at January 31, 2019 for the Central Pension Fund, May 31, 2019 for the Indiana Pension Laborers Fund, December 31, 2018 for the Pipeline Industry Benefit Fund, December 31, 2018 for the Laborers District Council & Contractors’ Pension Fund of Ohio, April 30, 2019 for the Ohio Operating Engineers Pension Fund, April 30, 2019 for the Operating Engineers Local 324 Fringe Benefit Fund, December 31, 2018 for the Minnesota Laborers Pension Fund, and December 31, 2018 for the Laborers’ Combined Fund of Western Pennsylvania. Generally, plans in the red zone are less than 65% funded, plans in the yellow zone are less than 80% funded and plans in the green zone are at least 80% funded. The FIP/RP Status Pending / Implemented column indicates plans for which a FIP or RP is either pending or has been implemented. The multi-employer contributions listed in the table below are CenterPoint Energy’s multi-employer contributions made in 2019. Federal law requires pension plans in endangered status to adopt a FIP and plans in critical status to adopt a RP aimed at restoring the financial health of the plan. In December 2014, the Multi-employer Pension Reform Act of 2014 was passed and permanently extended the Pension Protection Act of 2006 multi-employer plan critical and endangered status funding rules, among other things, including providing a provision for a plan sponsor to suspend or reduce benefit payments to preserve plans in critical and declining status. Pension Protection Act Zone Status Multi-employer Contributions Pension Fund EIN/Pension Plan Number 2019 FIP/RP Status Pending/Implemented 2019 Surcharge Imposed (in millions) Central Pension Fund 36-6052390-001 Green No $ 12 No Indiana Laborers Pension Fund 35-6027150-001 Green No 5 No Pipeline Industry Benefit Fund 73-0742835-001 Green No 5 No Laborers District Fund of Ohio 31-6129964-001 Green No 4 No Ohio Operating Engineers Pension Fund 31-6129968-001 Green No 3 No Operating Engineers Local #324 Fund (1) 38-1900637-001 Red Implemented 3 No Minnesota Laborers Pension Fund 41-6159599-001 Green No 3 No Laborers’ Combined Fund of Western PA (2) 25-6135576-001 Red Implemented 2 No Other 15 Total Contributions $ 52 (1) The Operating Engineers Local #324 Fringe Benefits Fund was certified to be in “critical” status for the plan year ending April 30, 2019. In an effort to improve the plan’s funding situation, on March 17, 2011, the trustees adopted a plan amendment, which reduced benefit accruals and eliminated some ancillary benefits, and adopted an RP that will be effective from May 1, 2013 through April 30, 2023 or until the plan is no longer in critical status. On April 27, 2015, the trustees updated the RP to change the annual standard for meeting the requirements of the RP. The trustees further updated the RP on January 29, 2019. The annual standard is that actuarial projections updated for each year show the fund is expected to remain solvent for a 20-year projection period. (2) The Laborers’ Combined Fund of Western Pennsylvania was previously deemed in critical status. The trustees adopted a FIP that is scheduled to run through December 31, 2020 and provided for changes in adjustable benefits and increases in the employer contribution rate. While not considered significant to CenterPoint Energy, there are four plans in red zone status receiving CenterPoint Energy contributions. There are also five other plans where CenterPoint Energy contributions exceed 5% of each plan’s total contributions; however, none of these plans are considered significant to CenterPoint Energy. On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. As a result, CenterPoint Energy will no longer participate in the multi-employer pension plans discussed above. (c) Postretirement Benefits CenterPoint Energy provides certain healthcare and life insurance benefits for eligible retired employees on both a contributory and non-contributory basis. The Registrants’ employees (other than employees of Vectren and its subsidiaries) who were hired before January 1, 2018 and who have met certain age and service requirements at retirement, as defined in the plans, are eligible to participate in these benefit plans. Employees hired on or after January 1, 2018 are not eligible for these benefits, except that such employees represented by IBEW Local Union 66 are eligible to participate in certain of the benefits, subject to the applicable age and service requirements. With respect to retiree medical and prescription drug benefits, employees represented by the IBEW Local Union 66 who retire on or after January 1, 2017, and their dependents, receive any such benefits exclusively through the NECA/IBEW Family Medical Care Plan pursuant to the terms of the renegotiated collective bargaining agreement entered into in May 2016. Houston Electric and CERC are required to fund a portion of their obligations in accordance with rate orders. All other obligations are funded on a pay-as-you-go basis. As a result of the Merger, CenterPoint Energy now maintains an additional postretirement benefit plan. The postretirement benefit plan provides health care and life insurance benefits, which are a combination of self-insured and fully insured programs, to eligible Vectren retirees on both a contributory and non-contributory basis. Postretirement benefits are accrued over the active service period of employees. The net postretirement benefit cost includes the following components: Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Service cost (1) $ 3 $ 1 $ 1 $ 2 $ — $ 1 $ 2 $ 1 $ 1 Interest cost (2) 15 7 5 13 8 4 16 9 5 Expected return on plan assets (2) (5 ) (4 ) (1 ) (5 ) (4 ) (1 ) (5 ) (4 ) (1 ) Amortization of prior service cost (credit) (2) (5 ) (6 ) 1 (5 ) (5 ) 1 (5 ) (6 ) 1 Net postretirement benefit cost (credit) $ 8 $ (2 ) $ 6 $ 5 $ (1 ) $ 5 $ 8 $ — $ 6 (1) Amounts presented in the table above are included in Operation and maintenance expense in each of the Registrants’ respective Statements of Consolidated Income, net of regulatory deferrals and amounts capitalized. (2) Amounts presented in the table above are included in Other, net in each of the Registrants’ respective Statements of Consolidated Income, net of regulatory deferrals. The following assumptions were used to determine net periodic cost relating to postretirement benefits: Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC Discount rate 3.20 % 3.20 % 3.20 % 3.60 % 3.60 % 3.60 % 4.15 % 4.15 % 4.15 % Expected return on plan assets 4.60 4.70 4.15 4.55 4.75 3.85 4.50 4.75 3.60 The following table summarizes changes in the benefit obligation, plan assets, the amounts recognized in consolidated balance sheets and the key assumptions of the postretirement plans. The measurement dates for plan assets and benefit obligations were December 31, 2019 and 2018 . December 31, 2019 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Change in Benefit Obligation Benefit obligation, beginning of year $ 331 $ 166 $ 110 $ 386 $ 225 $ 109 Plan obligations assumed in Merger 37 — — — — — Service cost 3 1 1 2 — 1 Interest cost 15 7 5 13 8 4 Participant contributions 8 2 4 7 2 4 Benefits paid (26 ) (13 ) (8 ) (25 ) (13 ) (9 ) Plan amendment 9 3 5 — — — Actuarial (gain) loss (1) (21 ) (4 ) (15 ) (52 ) (56 ) 1 Benefit obligation, end of year 356 162 102 331 166 110 Change in Plan Assets Fair value of plan assets, beginning of year 114 89 25 120 93 26 Employer contributions 17 10 3 14 9 4 Participant contributions 8 2 4 7 2 4 Benefits paid (26 ) (13 ) (8 ) (25 ) (13 ) (9 ) Actual investment return 15 13 3 (2 ) (2 ) — Fair value of plan assets, end of year 128 101 27 114 89 25 Funded status, end of year $ (228 ) $ (61 ) $ (75 ) $ (217 ) $ (77 ) $ (85 ) Amounts Recognized in Balance Sheets Current liabilities-other $ (8 ) $ — $ (3 ) $ (6 ) $ — $ (3 ) Other liabilities-benefit obligations (220 ) (61 ) (72 ) (211 ) (77 ) (82 ) Net liability, end of year $ (228 ) $ (61 ) $ (75 ) $ (217 ) $ (77 ) $ (85 ) Actuarial Assumptions Discount rate (2) 3.25 % 3.25 % 3.25 % 4.35 % 4.35 % 4.35 % Expected return on plan assets (3) 3.95 4.05 3.35 4.60 4.70 4.15 Medical cost trend rate assumed for the next year - Pre-65 5.50 5.50 5.50 5.95 5.95 5.95 Medical/prescription drug cost trend rate assumed for the next year - Post-65 5.75 5.75 5.75 28.60 28.60 28.60 Prescription drug cost trend rate assumed for the next year - Pre-65 8.00 8.00 8.00 9.20 9.20 9.20 Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 4.50 4.50 4.50 4.50 4.50 4.50 Year that the cost trend rates reach the ultimate trend rate - Pre-65 2028 2028 2028 2026 2026 2026 Year that the cost trend rates reach the ultimate trend rate - Post-65 2029 2029 2029 2027 2027 2027 (1) Significant sources of gain for 2019 include favorable cost trend rates and benefit claims experience in addition to the change in mortality projection scale from MP2018 to MP2019. Significant sources of gain for 2018 include the increase in the discount rate from 3.60% to 4.35% , favorable benefit claims experience and cost trend rates in addition to the change in mortality projection scale from MP2017 to MP2018. (2) The discount rate assumption was determined by matching the projected cash flows of the plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years. (3) The expected rate of return assumption was developed using the targeted asset allocation of the plans and the expected return for each asset class. (d) Accumulated Other Comprehensive Income (Loss) (CenterPoint Energy and CERC) CenterPoint Energy recognizes the funded status of its pension and other postretirement plans on its Consolidated Balance Sheets. To the extent this obligation exceeds amounts previously recognized in the Statements of Consolidated Income, CenterPoint Energy records a regulatory asset for that portion related to its rate regulated utilities. To the extent that excess liability does not relate to a rate regulated utility, the offset is recorded as a reduction to equity in accumulated other comprehensive income. Amounts recognized in accumulated other comprehensive loss (gain) consist of the following: December 31, 2019 2018 Pension Benefits Postretirement Benefits Pension Benefits Postretirement Benefits CenterPoint Energy CenterPoint Energy CERC CenterPoint Energy CenterPoint Energy CERC (in millions) Unrecognized actuarial loss (gain) $ 105 $ (16 ) $ (12 ) $ 109 $ (7 ) $ (3 ) Unrecognized prior service cost — 7 7 1 5 5 Deferred tax benefit — — — — — (9 ) Net amount recognized in accumulated other comprehensive loss (gain) $ 105 $ (9 ) $ (5 ) $ 110 $ (2 ) $ (7 ) The changes in plan assets and benefit obligations recognized in other comprehensive income during 2019 are as follows: Pension Benefits Postretirement Benefits CenterPoint Energy CenterPoint Energy CERC (in millions) Net loss (gain) $ 4 $ (8 ) $ (6 ) Amortization of net loss (8 ) — — Amortization of prior service cost (1 ) 1 (1 ) Total recognized in comprehensive income $ (5 ) $ (7 ) $ (7 ) Total expense recognized in net periodic costs and Other comprehensive income $ 87 $ 1 $ (1 ) (e) Pension Plan Assets (CenterPoint Energy) In managing the investments associated with the benefit plans, CenterPoint Energy’s objective is to achieve and maintain a fully funded plan. This objective is expected to be achieved through an investment strategy that manages liquidity requirements while maintaining a long-term horizon in making investment decisions and efficient and effective management of plan assets. As part of the investment strategy discussed above, CenterPoint Energy maintained the following weighted average allocation targets for its pension plans as of December 31, 2019 : Minimum Maximum U.S. equity 19 % 29 % International equity 8 % 18 % Real estate 3 % 9 % Fixed income 52 % 62 % Cash 0 % 2 % The following tables set forth by level, within the fair value hierarchy (see Note 10 ), CenterPoint Energy’s pension plan assets at fair value as of December 31, 2019 and 2018 : Fair Value Measurements as of December 31, 2019 2018 (Level 1) (Level 2) (Level 3) Total (Level 1) (Level 2) (Level 3) Total (in millions) Cash $ (7 ) $ — $ — $ (7 ) $ 19 $ — $ — $ 19 Corporate bonds: Investment grade or above — 699 — 699 — 368 — 368 Equity securities: U.S. companies 69 — — 69 60 — — 60 Cash received as collateral from securities lending 61 — — 61 77 — — 77 U.S. treasuries 232 — — 232 196 — — 196 Mortgage backed securities — 8 — 8 — 6 — 6 Asset backed securities — 3 — 3 — 1 — 1 Municipal bonds — 44 — 44 — 27 — 27 Mutual funds (2) 270 — — 270 167 — — 167 International government bonds — 21 — 21 — 16 — 16 Obligation to return cash received as collateral from securities lending (61 ) — — (61 ) (77 ) — — (77 ) Total investments at fair value $ 564 $ 775 $ — $ 1,339 $ 442 $ 418 $ — $ 860 Investments measured by net asset value per share or its equivalent (1) (2) 666 656 Total Investments $ 2,005 $ 1,516 (1) Represents investments in common collective trust funds. (2) The amounts invested in mutual funds and common collective trust funds were allocated as follows: As of December 31, 2019 2018 Mutual Funds Common Collective Trust Funds Mutual Funds Common Collective Trust Funds International equities (1) 31 % 29 % 85 % 41 % U.S. equities 49 % 51 % 15 % 5 % Real estate 1 % 6 % — % — % Fixed income 19 % 14 % — % 54 % (1) The amounts invested in international equities for 2018 include allocations of 34% in mutual funds and 4% in common collective trust funds,which were previously reported as allocations in emerging market equities. The pension plans utilized both exchange traded and over-the-counter financial instruments such as futures, interest rate options and swaps that were marked to market daily with the gains/losses settled in the cash accounts. The pension plans did not include any holdings of CenterPoint Energy Common Stock as of December 31, 2019 or 2018 . (f) Postretirement Plan Assets In managing the investments associated with the postretirement plans, the Registrants’ objective is to achieve and maintain a fully funded plan. This objective is expected to be achieved through an investment strategy that manages liquidity requirements while maintaining a long-term horizon in making investment decisions and efficient and effective management of plan assets. As part of the investment strategy discussed above, the Registrants maintained the following weighted average allocation targets for the postretirement plans as of December 31, 2019 : CenterPoint Energy Houston Electric CERC Minimum Maximum Minimum Maximum Minimum Maximum U.S. equity 13 % 23 % 13 % 23 % 15 % 25 % International equity 3 % 13 % 3 % 13 % 2 % 12 % Fixed income 69 % 79 % 69 % 79 % 68 % 78 % Cash 0 % 2 % 0 % 2 % 0 % 2 % The following table presents mutual funds by level, within the fair value hierarchy, the Registrants’ postretirement plan assets at fair value as of December 31, 2019 and 2018 : Fair Value Measurements as of December 31, 2019 2018 Mutual Funds (Level 1) (Level 2) (Level 3) Total Total (in millions) CenterPoint Energy $ 128 $ — $ — $ 128 $ 114 $ — $ — $ 114 Houston Electric 101 — — 101 89 — — 89 CERC 27 — — 27 25 — — 25 The amounts invested in mutual funds were allocated as follows: As of December 31, 2019 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC Fixed income 71 % 71 % 69 % 74 % 74 % 73 % U.S. equities 21 % 21 % 24 % 19 % 19 % 21 % International equities 8 % 8 % 7 % 7 % 7 % 6 % (g) Benefit Plan Contributions The Registrants made the following contributions in 2019 and expect to make the following minimum contributions in 2020 to the indicated benefit plans below: Contributions in 2019 Expected Minimum Contributions in 2020 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Qualified pension plans $ 86 $ — $ — $ 76 $ — $ — Non-qualified pension plans 23 — — 7 — — Postretirement benefit plans 17 10 3 17 9 3 The following benefit payments are expected to be paid by the pension and postretirement benefit plans: Pension Benefits Postretirement Benefits CenterPoint Energy CenterPoint Energy Houston Electric CERC (in millions) 2020 $ 180 $ 18 $ 8 $ 5 2021 178 18 8 4 2022 180 19 9 5 2023 181 20 10 5 2024 177 21 10 6 2025-2029 824 112 54 30 (h) Savings Plan CenterPoint Energy maintains the CenterPoint Energy Savings Plan, a tax-qualified employee savings plan that includes a cash or deferred arrangement under Section 401(k) of the Code, and an employee stock ownership plan under Section 4975(e)(7) of the Code. Under the plan, participating employees may make pre-tax or Roth contributions and, if eligible, after-tax contributions up to certain federally mandated limits. Participating Registrants provide matching contributions and, as of January 1, 2020, nonelective contributions, if eligible, up to certain limits. CenterPoint Energy, through the Merger, also acquired additional defined contribution retirement savings plans sponsored by Vectren and its subsidiaries that are qualified under sections 401(a) and 401(k) of the Code, one of which merged into the CenterPoint Energy Savings Plan as of January 1, 2020. The CenterPoint Energy Savings Plan has significant holdings of Common Stock. As of December 31, 2019 , 11,051,800 shares of Common Stock were held by the savings plan, which represented approximately 13% of its investments. Given the concentration of the investments in Common Stock, the savings plan and its participants have market risk related to this investment. The savings plan limits the percentage of future contributions that can be invested in Common Stock to 25% and prohibits transfers of account balances where the transfer would result in more than 25% of a participant’s total account balance invested in Common Stock. CenterPoint Energy allocates the savings plan benefit expense to Houston Electric and CERC related to their respective employees. The following table summarizes the Registrants’ savings plan benefit expense for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Savings plan benefit expenses (1) $ 58 $ 18 $ 18 $ 43 $ 17 $ 18 $ 41 $ 17 $ 17 (1) Amounts presented in the table above are included in Operation and maintenance expense in the Registrants’ respective Statements of Consolidated Income and shown prior to any amounts capitalized. (i) Other Benefits Plans The Registrants participate in CenterPoint Energy’s plans that provide postemployment benefits for certain former or inactive employees, their beneficiaries and covered dependents, after employment but before retirement (primarily healthcare and life insurance benefits for participants in the long-term disability plan). CenterPoint Energy maintains non-qualified deferred compensation plans, including plans acquired in the Merger, that provide benefits payable to eligible directors, officers and select employees or their designated beneficiaries at specified future dates or upon termination, retirement or death. Benefit payments are made from the general assets of the participating Registrants. Expenses related to other benefit plans were recorded as follows: Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Postemployment benefits $ 2 $ 1 $ 1 $ 3 $ 4 $ 1 $ 6 $ 1 $ 4 Deferred compensation plans 4 1 — 3 1 — 3 1 — Amounts related to other benefit plans were included in Benefit Obligations in the Registrants’ accompanying Consolidated Balance Sheets as follows: December 31, 2019 December 31, 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Postemployment benefits $

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments [Text Block]	Derivative Instruments The Registrants are exposed to various market risks. These risks arise from transactions entered into in the normal course of business. The Registrants utilize derivative instruments such as physical forward contracts, swaps and options to mitigate the impact of changes in commodity prices, weather and interest rates on operating results and cash flows. (a) Non-Trading Activities Commodity Derivative Instruments (CenterPoint Energy and CERC). CenterPoint Energy, through its Indiana utilities, and CERC, through CES, enter into certain derivative instruments to mitigate the effects of commodity price movements. Certain financial instruments used to hedge portions of the natural gas inventory of the Energy Services reportable segment are designated as fair value hedges for accounting purposes. Outstanding derivative instruments designated as economic hedges at the Indiana Utilities hedge long-term variable rate natural gas purchases. The Indiana Utilities have authority to refund and recover mark-to-market gains and losses associated with hedging natural gas purchases, and thus the gains and losses on derivatives are deferred in a regulatory liability or asset. All other financial instruments do not qualify or are not designated as cash flow or fair value hedges. On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. Interest Rate Risk Derivative Instruments. From time to time, the Registrants may enter into interest rate derivatives that are designated as economic or cash flow hedges. The objective of these hedges is to offset risk associated with interest rates borne by the Registrants in connection with an anticipated future fixed rate debt offering or other exposure to variable rate debt. The Indiana Utilities have authority to refund and recover mark-to-market gains and losses associated with hedging financing activity, and thus the gains and losses on derivatives are deferred in a regulatory liability or asset. For the impacts of cash flow hedges to Accumulated other comprehensive income, see Note 13 . The table below summarizes the Registrants’ outstanding interest rate hedging activity: December 31, 2019 December 31, 2018 Hedging Classification Notional Principal CenterPoint Energy (1) Houston Electric CenterPoint Energy Houston Electric (in millions) Economic hedge $ 84 $ — $ — $ — Cash flow hedge — — 450 450 (1) Relates to interest rate derivative instruments at SIGECO. Weather Hedges (CenterPoint Energy and CERC). CenterPoint Energy and CERC have weather normalization or other rate mechanisms that largely mitigate the impact of weather on NGD in Arkansas, Indiana, Louisiana, Mississippi, Minnesota, Ohio and Oklahoma, as applicable. CenterPoint Energy’s and CERC’s NGD in Texas and CenterPoint Energy’s electric operations in Texas and Indiana do not have such mechanisms, although fixed customer charges are historically higher in Texas for NGD compared to its other jurisdictions. As a result, fluctuations from normal weather may have a positive or negative effect on CenterPoint Energy’s and CERC’s NGD’s results in Texas and on CenterPoint Energy’s electric operations’ results in its Texas and Indiana service territories. CenterPoint Energy and CERC, as applicable, enter into winter season weather hedges from time to time for certain NGD jurisdictions and electric operations’ service territory to mitigate the effect of fluctuations from normal weather on results of operations and cash flows. These weather hedges are based on heating degree days at 10 -year normal weather. Houston Electric and Indiana Electric do not enter into weather hedges. The tables below summarizes CenterPoint Energy’s and CERC’s weather hedge gain (loss) activity: CenterPoint Energy Year Ended December 31, Texas Operations Winter Season Bilateral Cap 2019 2018 2017 (in millions) NGD 2019 – 2020 $ 8 $ 2 $ — $ — NGD 2018 – 2019 9 — — — NGD 2017 – 2018 8 — (2 ) — Electric operations 2019 – 2020 7 3 — — Electric operations 2018 – 2019 8 3 — — Electric operations 2017 – 2018 9 — (2 ) — Electric operations 2016 – 2017 9 — — (1 ) Total CenterPoint Energy (1) $ 8 $ (4 ) $ (1 ) CERC Year Ended December 31, Texas Operations Winter Season Bilateral Cap 2019 2018 2017 (in millions) NGD 2019 – 2020 $ 8 $ 2 $ — $ — NGD 2018 – 2019 9 — — — NGD 2017 – 2018 8 — (2 ) — Total CERC (1) $ 2 $ (2 ) $ — (1) Weather hedge gains (losses) are recorded in Revenues in the Statements of Consolidated Income. (b) Derivative Fair Values and Income Statement Impacts The following tables present information about derivative instruments and hedging activities. The first three tables provide a balance sheet overview of Derivative Assets and Liabilities as of December 31, 2019 and 2018 , while the last two tables provide a breakdown of the related income statement impacts for the years ending December 31, 2019 , 2018 and 2017 . Fair Value of Derivative Instruments and Hedged Items CenterPoint Energy December 31, 2019 December 31, 2018 Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Derivatives designated as cash flow hedges: Interest rate derivatives Current Liabilities: Non-trading derivative liabilities $ — $ — $ — $ 24 Derivatives designated as fair value hedges: Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities 12 — 1 7 Derivatives not designated as hedging instruments: Natural gas derivatives (1) (2) (3) Current Assets: Non-trading derivative assets 139 3 103 3 Natural gas derivatives (1) (2) (3) Other Assets: Non-trading derivative assets 58 — 38 — Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities 73 184 62 173 Natural gas derivatives (1) (2) (3) Other Liabilities: Non-trading derivative liabilities 10 54 16 25 Interest rate derivatives Other Liabilities — 10 — — Indexed debt securities derivative Current Liabilities — 893 — 601 Total CenterPoint Energy $ 292 $ 1,144 $ 220 $ 833 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 2,226 Bcf or a net 374 Bcf long position and 1,674 Bcf or a net 140 Bcf long position as of December 31, 2019 and 2018 , respectively. Certain natural gas contracts hedge basis risk only and lack a fixed price exposure. (2) Natural gas contracts are presented on a net basis in CenterPoint Energy’s Consolidated Balance Sheets as they are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within CenterPoint Energy’s Consolidated Balance Sheets. The net of total non-trading natural gas derivative assets and liabilities is detailed in the Offsetting of Natural Gas Derivative Assets and Liabilities table below. (3) Derivative Assets and Derivative Liabilities include no material amounts related to physical forward transactions with Enable. Houston Electric December 31, 2019 December 31, 2018 Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Derivatives designated as cash flow hedges: Interest rate derivatives Current Liabilities: Non-trading derivative liabilities $ — $ — $ — $ 24 Total Houston Electric $ — $ — $ — $ 24 CERC December 31, 2019 December 31, 2018 Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Derivatives designated as fair value hedges: Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities $ 12 $ — $ 1 $ 7 Derivatives not designated as hedging instruments: Natural gas derivatives (1) (2) (3) Current Assets: Non-trading derivative assets 139 3 103 3 Natural gas derivatives (1) (2) (3) Other Assets: Non-trading derivative assets 58 — 38 — Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities 73 177 62 173 Natural gas derivatives (1) (2) (3) Other Liabilities: Non-trading derivative liabilities 10 39 16 25 Total CERC $ 292 $ 219 $ 220 $ 208 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 2,226 Bcf or a net 374 Bcf long position and 1,674 Bcf or a net 140 Bcf long position as of December 31, 2019 and 2018 , respectively. Certain natural gas contracts hedge basis risk only and lack a fixed price exposure. (2) Natural gas contracts are presented on a net basis in CERC’s Consolidated Balance Sheets as they are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within CERC’s Consolidated Balance Sheets. The net of total non-trading natural gas derivative assets and liabilities is detailed in the Offsetting of Natural Gas Derivative Assets and Liabilities table below. (3) Derivative Assets and Derivative Liabilities include no material amounts related to physical forward transactions with Enable. Cumulative Basis Adjustment for Fair Value Hedges (CenterPoint Energy and CERC) CenterPoint Energy December 31, 2019 December 31, 2018 Balance Sheet Location Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item (in millions) Hedged items in fair value hedge relationship: Natural gas inventory Current Assets: Natural gas inventory $ 47 $ (13 ) $ 57 $ 1 Total CenterPoint Energy $ 47 $ (13 ) $ 57 $ 1 CERC December 31, 2019 December 31, 2018 Balance Sheet Location Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item (in millions) Hedged items in fair value hedge relationship: Natural gas inventory Current Assets: Natural gas inventory $ 47 $ (13 ) $ 57 $ 1 Total CERC $ 47 $ (13 ) $ 57 $ 1 Offsetting of Natural Gas Derivative Assets and Liabilities (CenterPoint Energy and CERC) CenterPoint Energy December 31, 2019 December 31, 2018 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 224 $ (88 ) $ 136 $ 166 $ (66 ) $ 100 Other Assets: Non-trading derivative assets 68 (10 ) 58 54 (16 ) 38 Current Liabilities: Non-trading derivative liabilities (187 ) 136 (51 ) (183 ) 81 (102 ) Other Liabilities: Non-trading derivative liabilities (54 ) 25 (29 ) (25 ) 20 (5 ) Total CenterPoint Energy $ 51 $ 63 $ 114 $ 12 $ 19 $ 31 CERC December 31, 2019 December 31, 2018 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 224 $ (88 ) $ 136 $ 166 $ (66 ) $ 100 Other Assets: Non-trading derivative assets 68 (10 ) 58 54 (16 ) 38 Current Liabilities: Non-trading derivative liabilities (180 ) 136 (44 ) (183 ) 81 (102 ) Other Liabilities: Non-trading derivative liabilities (39 ) 25 (14 ) (25 ) 20 (5 ) Total CERC $ 73 $ 63 $ 136 $ 12 $ 19 $ 31 (1) Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements. (2) The derivative assets and liabilities on the Registrant’s respective Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default. Income Statement Impact of Hedge Accounting Activity (CenterPoint Energy and CERC) CenterPoint Energy Year Ended December 31, 2019 2018 2017 Location and Amount of Gain (Loss) recognized in Income on Hedging Relationship (1) Non-utility cost of revenues, including natural gas (in millions) Total amounts presented in the statements of income in which the effects of hedges are recorded $ 4,029 $ 4,364 $ 3,785 Gain (loss) on fair value hedging relationships: Commodity contracts: Hedged items - Natural gas inventory (14 ) (13 ) 14 Derivatives designated as hedging instruments 14 13 (14 ) Amounts excluded from effectiveness testing recognized in earnings immediately (213 ) (149 ) (67 ) (1) Income statement impact associated with cash flow hedge activity is related to gains and losses reclassified from Accumulated other comprehensive income into income. Amounts are immaterial for the years ended December 31, 2019 , 2018 and 2017 , respectively. CERC Year Ended December 31, 2019 2018 2017 Location and Amount of Gain (Loss) recognized in Income on Hedging Relationship (1) Non-utility cost of revenues, including natural gas (in millions) Total amounts presented in the statements of income in which the effects of hedges are recorded $ 3,503 $ 4,364 $ 3,785 Gain (loss) on fair value hedging relationships: Commodity contracts: Hedged items - Natural gas inventory (14 ) (13 ) 14 Derivatives designated as hedging instruments 14 13 (14 ) Amounts excluded from effectiveness testing recognized in earnings immediately (213 ) (149 ) (67 ) (1) Income statement impact associated with cash flow hedge activity is related to gains and losses reclassified from Accumulated other comprehensive income into income. Amounts are immaterial for the years ended December 31, 2019 , 2018 and 2017 , respectively. CenterPoint Energy Year Ended December 31, Income Statement Location 2019 2018 2017 (in millions) Effects of derivatives not designated as hedging instruments on the income statement: Commodity contracts Gains (Losses) in Non-utility revenues $ 214 $ 107 $ 211 Indexed debt securities derivative Gain (loss) on indexed debt securities (292 ) (232 ) 49 Interest rate derivatives Gains in Other Income (Expense) — 2 — Total CenterPoint Energy $ (78 ) $ (123 ) $ 260 CERC Year Ended December 31, Income Statement Location 2019 2018 2017 (in millions) Effects of derivatives not designated as hedging instruments on the income statement: Commodity contracts Gains (Losses) in Non-utility revenues $ 214 $ 107 $ 211 Total CERC $ 214 $ 107 $ 211 (c) Credit Risk Contingent Features (CenterPoint Energy and CERC) CenterPoint Energy and CERC enter into financial derivative contracts containing material adverse change provisions. These provisions could require CenterPoint Energy or CERC to post additional collateral if the S&P or Moody’s credit ratings of CenterPoint Energy, Inc. or its subsidiaries, including CERC Corp., are downgraded. December 31, 2019 December 31, 2018 CenterPoint Energy CERC CenterPoint Energy CERC (in millions) Aggregate fair value of derivatives containing material adverse change provisions in a net liability position $ 1 $ 1 $ 1 $ 1 Fair value of collateral already posted — — — — Additional collateral required to be posted if credit risk contingent features triggered 1 1 — — (d) Credit Quality of Counterparties (CenterPoint Energy and CERC) In addition to the risk associated with price movements, credit risk is also inherent in CenterPoint Energy’s and CERC’s non-trading derivative activities. Credit risk relates to the risk of loss resulting from non-performance of contractual obligations by a counterparty. The following tables show the composition of counterparties to the non-trading derivative assets: CenterPoint Energy December 31, 2019 December 31, 2018 Investment Grade (1) Total (3) Investment Grade (1) Total (3) (in millions) Energy marketers $ 4 $ 16 $ 11 $ 24 End users (2) 27 178 30 114 Total CenterPoint Energy $ 31 $ 194 $ 41 $ 138 CERC December 31, 2019 December 31, 2018 Investment Grade (1) Total (3) Investment Grade (1) Total (3) (in millions) Energy marketers $ 4 $ 16 $ 11 $ 24 End users (2) 27 178 30 114 Total CERC $ 31 $ 194 $ 41 $ 138 (1) “Investment grade” is primarily determined using publicly available credit ratings and considers credit support (including parent company guarantees) and collateral (including cash and standby letters of credit). For unrated counterparties, CERC determines a synthetic credit rating by performing financial statement analysis and consider contractual rights and restrictions and collateral. (2) End users are comprised primarily of customers who have contracted to fix the price of a portion of their physical gas requirements for future periods. (3) The amounts reflected in the table above were not impacted by collateral netting.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements [Text Block]	Fair Value Measurements Assets and liabilities that are recorded at fair value in the Registrants’ Consolidated Balance Sheets are categorized based upon the level of judgment associated with the inputs used to measure their value. Hierarchical levels, as defined below and directly related to the amount of subjectivity associated with the inputs to fair valuations of these assets and liabilities, are as follows: Level 1: Inputs are unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date. The types of assets carried at Level 1 fair value generally are exchange-traded derivatives and equity securities, as well as natural gas inventory that has been designated as the hedged item in a fair value hedge. Level 2: Inputs, other than quoted prices included in Level 1, are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar instruments in active markets, and inputs other than quoted prices that are observable for the asset or liability. Fair value assets and liabilities that are generally included in this category are derivatives with fair values based on inputs from actively quoted markets. A market approach is utilized to value the Registrants’ Level 2 natural gas derivative assets or liabilities. CenterPoint Energy’s Level 2 indexed debt securities derivative is valued using an option model and a discounted cash flow model, which uses projected dividends on the ZENS-Related Securities and a discount rate as observable inputs. Level 3: Inputs are unobservable for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. Unobservable inputs reflect the Registrants’ judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. The Registrants develop these inputs based on the best information available, including the Registrants’ own data. A market approach is utilized to value the Registrants’ Level 3 assets or liabilities. As of December 31, 2019 , CenterPoint Energy’s and CERC’s Level 3 assets and liabilities are comprised of physical natural gas forward contracts and options. Level 3 physical natural gas forward contracts and options are valued using a discounted cash flow model which includes illiquid forward price curve locations (ranging from $1.44 to $5.20 per MMBtu for CenterPoint Energy and from $1.44 to $5.20 per MMBtu for CERC) as an unobservable input. CenterPoint Energy’s and CERC’s Level 3 physical natural gas forward contracts and options derivative assets and liabilities consist of both long and short positions (forwards and options). Forward price decreases (increases) as of December 31, 2019 would have resulted in lower (higher) values, respectively, for long forwards and options and higher (lower) values, respectively, for short forwards and options. The Registrants determine the appropriate level for each financial asset and liability on a quarterly basis and recognize transfers between levels at the end of the reporting period. The following tables present information about the Registrants’ assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis as of December 31, 2019 and December 31, 2018 , and indicate the fair value hierarchy of the valuation techniques utilized by the Registrants to determine such fair value. CenterPoint Energy December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Netting (1) Total Level 1 Level 2 Level 3 Netting (1) Total Assets (in millions) Corporate equities $ 825 $ — $ — $ — $ 825 $ 542 $ — $ — $ — $ 542 Investments, including money market funds (2) 49 — — — 49 66 — — — 66 Natural gas derivatives (3)(4) — 250 42 (98 ) 194 — 173 47 (82 ) 138 Hedged portion of natural gas inventory — — — — — 1 — — — 1 Total assets $ 874 $ 250 $ 42 $ (98 ) $ 1,068 $ 609 $ 173 $ 47 $ (82 ) $ 747 December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Netting (1) Total Level 1 Level 2 Level 3 Netting (1) Total Liabilities Indexed debt securities derivative $ — $ 893 $ — $ — $ 893 $ — $ 601 $ — $ — $ 601 Interest rate derivatives — 10 — — 10 24 — — — 24 Natural gas derivatives (3)(4) — 217 24 (161 ) 80 — 191 17 (101 ) 107 Hedged portion of natural gas inventory 13 — — — 13 — — — — — Total liabilities $ 13 $ 1,120 $ 24 $ (161 ) $ 996 $ 24 $ 792 $ 17 $ (101 ) $ 732 Houston Electric December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Netting Total Level 1 Level 2 Level 3 Netting Total Assets (in millions) Investments, including money market funds (2) $ 32 $ — $ — $ — $ 32 $ 48 $ — $ — $ — $ 48 Total assets $ 32 $ — $ — $ — $ 32 $ 48 $ — $ — $ — $ 48 Liabilities Interest rate derivatives $ — $ — $ — $ — $ — $ 24 $ — $ — $ — $ 24 Total liabilities $ — $ — $ — $ — $ — $ 24 $ — $ — $ — $ 24 CERC December 31, 2019 December 31, 2018 Level 2 Level 3 Netting (1) Total Level 2 Level 3 Netting (1) Total Assets (in millions) Corporate equities $ 2 $ — $ — $ — $ 2 $ 2 $ — $ — $ — $ 2 Investments, including money market funds (2) 11 — — — 11 11 — — — 11 Natural gas derivatives (3)(4) — 250 42 (98 ) 194 — 173 47 (82 ) 138 Hedged portion of natural gas inventory — — — — — 1 — — — 1 Total assets $ 13 $ 250 $ 42 $ (98 ) $ 207 $ 14 $ 173 $ 47 $ (82 ) $ 152 Liabilities Natural gas derivatives (3)(4) $ — $ 195 $ 24 $ (161 ) $ 58 $ — $ 191 $ 17 $ (101 ) $ 107 Hedged portion of natural gas inventory 13 — — — 13 — — — — — Total liabilities $ 13 $ 195 $ 24 $ (161 ) $ 71 $ — $ 191 $ 17 $ (101 ) $ 107 (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy and CERC to settle positive and negative positions and also include cash collateral posted with the same counterparties as follows: December 31, 2019 December 31, 2018 CenterPoint Energy CERC CenterPoint Energy CERC (in millions) Cash collateral posted with the same counterparties $ 63 $ 63 $ 19 $ 19 (2) Amounts are included in Prepaid and Other Current Assets and Other Assets in the Consolidated Balance Sheets. (3) Natural gas derivatives include no material amounts related to physical forward transactions with Enable. (4) Level 1 natural gas derivatives include exchange-traded derivatives cleared by the CME, which deems that financial instruments cleared by the CME are settled daily in connection with posted cash payments. As a result of this exchange rule, CME-related derivatives are considered to have no fair value at the balance sheet date for financial reporting purposes, and are presented in Level 1 net of posted cash; however, the derivatives remain outstanding and subject to future commodity price fluctuations until they are settled in accordance with their contractual terms. Derivative transactions cleared on exchanges other than the CME (e.g., the Intercontinental Exchange or ICE) continue to be reported on a gross basis. The following table presents additional information about assets or liabilities, including derivatives that are measured at fair value on a recurring basis for which CenterPoint Energy and CERC have utilized Level 3 inputs to determine fair value: Year Ended December 31, 2019 2018 2017 CenterPoint Energy CERC CenterPoint Energy CERC CenterPoint Energy CERC (in millions) Beginning balance $ 30 $ 30 $ (622 ) $ 46 $ (704 ) $ 13 Total gains 17 17 30 30 96 47 Total settlements (22 ) (22 ) (39 ) (39 ) (11 ) (11 ) Transfers into Level 3 (1 ) (1 ) 5 5 14 14 Transfers out of Level 3 (1) (6 ) (6 ) 656 (12 ) (17 ) (17 ) Ending balance (2) $ 18 $ 18 $ 30 $ 30 $ (622 ) $ 46 The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date: $ 12 $ 12 $ 18 $ 18 $ 87 $ 38 (1) During 2018, CenterPoint Energy transferred its indexed debt securities derivative from Level 3 to Level 2 to reflect changes in the significance of the unobservable inputs used in the valuation. (2) CenterPoint Energy and CERC did not have significant Level 3 purchases or sales during any of the years ended December 31, 2019 , 2018 or 2017. Estimated Fair Value of Financial Instruments The fair values of cash and cash equivalents, investments in debt and equity securities classified as “trading” and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. The carrying amounts of non-trading derivative assets and liabilities and CenterPoint Energy’s ZENS indexed debt securities derivative are stated at fair value and are excluded from the table below. The fair value of each debt instrument is determined by multiplying the principal amount of each debt instrument by a combination of historical trading prices and comparable issue data. These liabilities, which are not measured at fair value in the Registrants’ Consolidated Balance Sheets, but for which the fair value is disclosed, would be classified as Level 2 in the fair value hierarchy. December 31, 2019 December 31, 2018 CenterPoint Energy (1) Houston Electric (1) CERC CenterPoint Energy (1) Houston Electric (1) CERC Long-term debt, including current maturities (in millions) Carrying amount $ 15,093 $ 4,950 $ 2,546 $ 9,140 $ 4,717 $ 2,371 Fair value 16,067 5,457 2,803 9,308 4,770 2,488 (1) Includes Securitization Bond debt. Items measured at Fair Value on a Non-recurring Basis CenterPoint Energy and CERC recorded a goodwill impairment charge of $48 million

Unconsolidated Affiliate (Cente

Unconsolidated Affiliate (CenterPoint Energy and CERC)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Unconsolidated Affiliate (CenterPoint Energy and CERC) [Text Block]	Unconsolidated Affiliates (CenterPoint Energy and CERC) CenterPoint Energy has the ability to significantly influence the operating and financial policies of Enable, a publicly traded MLP, and, accordingly, accounts for its investment in Enable’s common units using the equity method of accounting. Enable is considered to be a VIE because the power to direct the activities that most significantly impact Enable’s economic performance does not reside with the holders of equity investment at risk. However, CenterPoint Energy is not considered the primary beneficiary of Enable since it does not have the power to direct the activities of Enable that are considered most significant to the economic performance of Enable. As of December 31, 2019 , CenterPoint Energy’s maximum exposure to loss related to Enable is limited to its investment in unconsolidated affiliate, its investment in Enable Series A Preferred Units and outstanding current accounts receivable from Enable. Investment in Unconsolidated Affiliates (CenterPoint Energy): December 31, 2019 December 31, 2018 (in millions) Enable $ 2,406 $ 2,482 Other (1) 2 — Total $ 2,408 $ 2,482 (1) Represents the fair value of non-utility equity investments acquired in the Merger. CenterPoint Energy evaluates its equity method investments for impairment when factors indicate that a decrease in value of its investment has occurred and the carrying amount of its investment may not be recoverable. An impairment loss is recognized in earnings when an impairment is deemed to be other than temporary. As of December 31, 2019, CenterPoint Energy’s investment in Enable is $10.29 per unit and Enable’s common unit price closed at $10.03 per unit (approximately $61 million below carrying value). Based on an analysis of its investment in Enable as of December 31, 2019, CenterPoint Energy believes that the decline in the value of its investment is temporary, and that the carrying value of its investment of $2.4 billion will be recovered. Equity in Earnings of Unconsolidated Affiliates, net (CenterPoint Energy): Year Ended December 31, 2019 2018 2017 (in millions) Enable (1) $ 229 $ 307 $ 265 Other 1 — — Total $ 230 $ 307 $ 265 (1) Equity earnings for the year ended December 31, 2019 includes CenterPoint Energy’s share of Enable’s $86 million goodwill impairment recorded in the fourth quarter of 2019. Limited Partner Interest and Units Held in Enable (CenterPoint Energy): As of December 31, 2019 2018 Limited Partner Interest (1) Common Units Enable Series A Preferred Units (2) Limited Partner Interest (1) Common Units Enable Series A Preferred Units (2) CenterPoint Energy (3) 53.7 % 233,856,623 14,520,000 54.0 % 233,856,623 14,520,000 OGE 25.5 % 110,982,805 — 25.6 % 110,982,805 — Public unitholders 20.8 % 90,361,937 — 20.4 % 88,392,983 — Total Units Outstanding 100.0 % 435,201,365 14,520,000 100.0 % 433,232,411 14,520,000 (1) Excludes the Enable Series A Preferred Units owned by CenterPoint Energy. (2) The carrying amount of the Enable Series A Preferred Units, reflected as Preferred units - unconsolidated affiliate on CenterPoint Energy’s Consolidated Balance Sheets, was $363 million as of both December 31, 2019 and 2018 . No impairment charges or adjustment to carrying value were made as no observable price changes were identified in the current or prior reporting periods. (3) Prior to the Internal Spin completed in September 2018, CenterPoint Energy’s investment in Enable’s common units, excluding the Enable Series A Preferred Units held directly by CenterPoint Energy, was held indirectly through CERC. Generally, sales to any person or entity (including a series of sales to the same person or entity) of more than 5% of the aggregate of the common units CenterPoint Energy owns in Enable or sales to any person or entity (including a series of sales to the same person or entity) by OGE of more than 5% of the aggregate of the common units it owns in Enable are subject to mutual rights of first offer and first refusal set forth in Enable’s Agreement of Limited Partnership. Interests Held in Enable GP (CenterPoint Energy): CenterPoint Energy and OGE held the following interests in Enable GP as of both December 31, 2019 and 2018 : Management Rights (1) Incentive Distribution Rights (2) CenterPoint Energy (3) 50 % 40 % OGE 50 % 60 % (1) As of December 31, 2019 , Enable is controlled jointly by CenterPoint Energy and OGE. Sale of CenterPoint Energy’s or OGE’s ownership interests in Enable GP to a third party is subject to mutual rights of first offer and first refusal, and CenterPoint Energy is not permitted to dispose of less than all of its interest in Enable GP. (2) Enable is expected to pay a minimum quarterly distribution of $0.2875 per common unit on its outstanding common units to the extent it has sufficient cash from operations after establishment of cash reserves and payment of fees and expenses, including payments to Enable GP and its affiliates, within 60 days after the end of each quarter. If cash distributions to Enable’s unitholders exceed $0.330625 per common unit in any quarter, Enable GP will receive increasing percentages or incentive distributions rights, up to 50% , of the cash Enable distributes in excess of that amount. In certain circumstances Enable GP will have the right to reset the minimum quarterly distribution and the target distribution levels at which the incentive distributions receive increasing percentages to higher levels based on Enable’s cash distributions at the time of the exercise of this reset election. To date, no incentive distributions have been made. (3) Held indirectly through CNP Midstream. Distributions Received from Enable (CenterPoint Energy and CERC): CenterPoint Energy Year Ended December 31, 2019 2018 2017 Per Unit Cash Distribution Per Unit Cash Distribution Per Unit Cash Distribution (in millions, except per unit amounts) Enable common units (1) $ 1.2970 $ 303 $ 1.2720 $ 297 $ 1.2720 $ 297 Enable Series A Preferred Units 2.5000 36 2.5000 36 2.5000 36 Total CenterPoint Energy $ 339 $ 333 $ 333 CERC Year Ended December 31, 2018 2017 Per Unit Cash Distribution Per Unit Cash Distribution (in millions, except per unit amounts) Enable common units (1) $ 0.9540 $ 223 $ 1.2720 $ 297 Total CERC 223 297 (1) Prior to the Internal Spin completed in September 2018, distributions from Enable were received by CERC. After such date, distributions from Enable were received directly by CenterPoint Energy (through CNP Midstream). Transactions with Enable (CenterPoint Energy and CERC): Year Ended December 31, 2019 2018 2017 CenterPoint Energy (in millions) Natural gas expenses, including transportation and storage costs (1) $ 120 $ 122 $ 115 Reimbursement of support services (2) — 4 4 CERC Natural gas expenses, including transportation and storage costs (1) 120 122 115 Reimbursement of support services (2) — 4 4 (1) Included in Non-utility costs of revenues, including natural gas on CenterPoint Energy’s and CERC’s respective Statements of Consolidated Income. (2) Represents amounts billed for certain support services provided to Enable. Actual support services costs are recorded net of reimbursement. December 31, 2019 2018 CenterPoint Energy (in millions) Accounts payable for natural gas purchases from Enable $ 11 $ 11 Accounts receivable for amounts billed for services provided to Enable 2 2 CERC Accounts payable for natural gas purchases from Enable 11 11 Accounts receivable for amounts billed for services provided to Enable 2 2 CERC’s continuing involvement with Enable subsequent to the Internal Spin is limited to its natural gas purchases from Enable. Summarized consolidated income (loss) information for Enable is as follows: Year Ended December 31, 2019 2018 2017 (in millions) Operating revenues $ 2,960 $ 3,431 $ 2,803 Cost of sales, excluding depreciation and amortization 1,279 1,819 1,381 Depreciation and amortization 433 398 366 Operating income 569 648 528 Goodwill impairment 86 — — Net income attributable to Enable common units 360 485 400 Reconciliation of Equity in Earnings (Losses), net: CenterPoint Energy’s interest $ 193 $ 262 $ 216 Basis difference amortization (1) 47 47 49 Loss on dilution, net of proportional basis difference recognition (11 ) (2 ) — CenterPoint Energy’s equity in earnings, net $ 229 $ 307 $ 265 (1) Equity in earnings of unconsolidated affiliate includes CenterPoint Energy’s share of Enable earnings adjusted for the amortization of the basis difference of CenterPoint Energy’s original investment in Enable and its underlying equity in net assets of Enable. The basis difference is being amortized through the year 2048. Summarized consolidated balance sheet information for Enable is as follows: December 31, 2019 2018 (in millions) Current assets $ 389 $ 449 Non-current assets 11,877 11,995 Current liabilities 780 1,615 Non-current liabilities 4,077 3,211 Non-controlling interest 37 38 Preferred equity 362 362 Accumulated other comprehensive loss (3 ) — Enable partners’ equity 7,013 7,218 Reconciliation of Investment in Enable: CenterPoint Energy’s ownership interest in Enable partners’ equity $ 3,767 $ 3,896 CenterPoint Energy’s basis difference (1,361 ) (1,414 ) CenterPoint Energy’s equity method investment in Enable $ 2,406 $ 2,482 Discontinued Operations (CERC): On September 4, 2018, CERC completed the Internal Spin. CERC executed the Internal Spin to, among other things, enhance the access of CERC and CenterPoint Energy to low cost debt and equity through increased transparency and understandability of the financial statements, improve CERC’s credit quality by eliminating the exposure to Enable’s midstream business and provide clarity of internal reporting and performance metrics to enhance management’s decision making for CERC and CNP Midstream. The Internal Spin represents a significant strategic shift that has a material effect on CERC’s operations and financial results and, as a result, CERC’s distribution of its equity investment in Enable met the criteria for discontinued operations classification. CERC has no continuing involvement in the equity investment of Enable. Therefore, CERC’s equity in earnings and related income taxes have been classified as Income from discontinued operations, net of tax, in CERC’s Statements of Consolidated Income for the periods presented. CERC’s equity method investment and related deferred income tax liabilities have been classified as Investment in unconsolidated affiliate - discontinued operations and Deferred income taxes, net - discontinued operations, respectively, in CERC’s Consolidated Balance Sheets for the periods presented. The following table presents amounts included in Income from discontinued operations, net of tax in CERC’s Statements of Consolidated Income. Year Ended December 31, 2018 2017 (in millions) Equity in earnings of unconsolidated affiliate, net $ 184 $ 265 Income tax expense 46 104 Income from discontinued operations, net of tax $ 138 $ 161

Indexed Debt Securities (ZENS)

Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy)	12 Months Ended
	Dec. 31, 2019
Indexed Debt Securities [Abstract]
Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) [Text Block]	Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) (a) Investment in Securities Related to ZENS A subsidiary of CenterPoint Energy holds shares of certain securities detailed in the table below, which are classified as trading securities and are expected to be held to facilitate CenterPoint Energy’s ability to meet its obligation under the ZENS. Unrealized gains and losses resulting from changes in the market value of the ZENS-Related Securities are recorded in CenterPoint Energy’s Statements of Consolidated Income. Shares Held at December 31, 2019 2018 AT&T Common 10,212,945 10,212,945 Charter Common 872,503 872,912 (b) ZENS In September 1999, CenterPoint Energy issued ZENS having an original principal amount of $1.0 billion of which $828 million remained outstanding as of December 31, 2019 . Each ZENS is exchangeable at the holder’s option at any time for an amount of cash equal to 95% of the market value of the reference shares attributable to such note. The number and identity of the reference shares attributable to each ZENS are adjusted for certain corporate events. CenterPoint Energy’s reference shares for each ZENS consisted of the following: December 31, 2019 2018 (in shares) AT&T Common 0.7185 0.7185 Charter Common 0.061382 0.061382 CenterPoint Energy pays interest on the ZENS at an annual rate of 2% plus the amount of any quarterly cash dividends paid in respect of the reference shares attributable to the ZENS. The principal amount of the ZENS is subject to increases or decreases to the extent that the annual yield from interest and cash dividends on the reference shares is less than or more than 2.309% . The adjusted principal amount is defined in the ZENS instrument as “contingent principal.” As of December 31, 2019 , the ZENS, having an original principal amount of $828 million and a contingent principal amount of $75 million , were outstanding and were exchangeable, at the option of the holders, for cash equal to 95% of the market value of the reference shares attributable to the ZENS. As of December 31, 2019 , the market value of such shares was approximately $822 million , which would provide an exchange amount of $944 for each $1,000 original principal amount of ZENS. At maturity of the ZENS in 2029 , CenterPoint Energy will be obligated to pay in cash the higher of the contingent principal amount of the ZENS or an amount based on the then-current market value of the reference shares, which will include any additional publicly-traded securities distributed with respect to the current reference shares prior to maturity. The ZENS obligation is bifurcated into a debt component and a derivative component (the holder’s option to receive the appreciated value of the reference shares at maturity). The bifurcated debt component accretes through interest charges annually up to the contingent principal amount of the ZENS in 2029. Such accretion will be reduced by annual cash interest payments, as described above. The derivative component is recorded at fair value and changes in the fair value of the derivative component are recorded in CenterPoint Energy’s Statements of Consolidated Income. Changes in the fair value of the ZENS-Related Securities held by CenterPoint Energy are expected to substantially offset changes in the fair value of the derivative component of the ZENS. The following table sets forth summarized financial information regarding CenterPoint Energy’s investment in ZENS-Related Securities and each component of CenterPoint Energy’s ZENS obligation. ZENS-Related Securities Debt Component of ZENS Derivative Component of ZENS (in millions) Balance as of December 31, 2016 $ 953 $ 114 $ 717 Accretion of debt component of ZENS — 27 — 2% interest paid — (17 ) — Distribution to ZENS holders — (2 ) — Gain on indexed debt securities — — (49 ) Gain on ZENS-Related Securities 7 — — Balance as of December 31, 2017 960 122 668 Accretion of debt component of ZENS — 21 — 2% interest paid — (17 ) — Sale of ZENS-Related Securities (398 ) — — Distribution to ZENS holders — (102 ) (46 ) Gain on indexed debt securities — — (21 ) Loss on ZENS-Related Securities (22 ) — — Balance as of December 31, 2018 540 24 601 Accretion of debt component of ZENS — 17 — 2% interest paid — (17 ) — Distribution to ZENS holders — (5 ) — Loss on indexed debt securities — — 292 Gain on ZENS-Related Securities 282 — — Balance as of December 31, 2019 $ 822 $ 19 $ 893

Equity (CenterPoint Energy)

Equity (CenterPoint Energy)	12 Months Ended
	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
Equity (CenterPoint Energy) [Text Block]	Equity (CenterPoint Energy) Dividends Declared and Paid (CenterPoint Energy) CenterPoint Energy declared dividends on its Common Stock during 2019 , 2018 and 2017 as presented in the table below: Declaration Date Record Date Payment Date Per Share Total (in millions) October 17, 2019 November 21, 2019 December 12, 2019 $ 0.2875 $ 144 July 31, 2019 August 15, 2019 September 12, 2019 0.2875 145 April 25, 2019 May 16, 2019 June 13, 2019 0.2875 144 Total 2019 $ 0.8625 $ 433 December 12, 2018 February 21, 2019 March 14, 2019 $ 0.2875 $ 144 October 23, 2018 November 15, 2018 December 13, 2018 0.2775 139 July 26, 2018 August 16, 2018 September 13, 2018 0.2775 120 April 26, 2018 May 17, 2018 June 14, 2018 0.2775 120 Total 2018 $ 1.1200 $ 523 Declaration Date Record Date Payment Date Per Share Total (in millions) December 13, 2017 February 15, 2018 March 8, 2018 $ 0.2775 $ 120 October 25, 2017 November 16, 2017 December 8, 2017 0.2675 116 July 27, 2017 August 16, 2017 September 8, 2017 0.2675 115 April 27, 2017 May 16, 2017 June 9, 2017 0.2675 115 January 5, 2017 February 16, 2017 March 10, 2017 0.2675 115 Total 2017 $ 1.3475 $ 581 CenterPoint Energy declared dividends on its Series A Preferred Stock during 2019 and 2018 as presented in the table below: Declaration Date Record Date Payment Date Per Share Total (in millions) July 31, 2019 August 15, 2019 September 3, 2019 $ 30.6250 $ 24 Total 2019 $ 30.6250 $ 24 December 12, 2018 February 15, 2019 March 1, 2019 $ 32.1563 $ 26 Total 2018 $ 32.1563 $ 26 CenterPoint Energy declared dividends on its Series B Preferred Stock during 2019 and 2018 as presented in the table below: Declaration Date Record Date Payment Date Per Share Total October 17, 2019 November 15, 2019 December 2, 2019 $ 17.5000 $ 17 July 31, 2019 August 15, 2019 September 3, 2019 17.5000 17 April 25, 2019 May 15, 2019 June 3, 2019 17.5000 17 Total 2019 $ 52.5000 $ 51 December 12, 2018 February 15, 2019 March 1, 2019 $ 17.5000 $ 17 October 23, 2018 November 15, 2018 December 1, 2018 11.6667 11 Total 2018 $ 29.1667 $ 28 There were no Series A Preferred Stock or Series B Preferred Stock outstanding or dividends declared in 2017 . Dividend Requirement on Preferred Stock Year Ended December 31, 2019 2018 2017 (in millions) Series A Preferred Stock $ 49 $ 18 $ — Series B Preferred Stock 68 17 — Total preferred stock dividend requirement $ 117 $ 35 $ — Series A Preferred Stock On August 22, 2018, CenterPoint Energy completed the issuance of 800,000 shares of its Series A Preferred Stock, at a price of $1,000 per share, resulting in net proceeds of $790 million after issuance costs. The aggregate liquidation value of the Series A Preferred Stock is $800 million with a per share liquidation value of $1,000 . CenterPoint Energy used the net proceeds from the Series A Preferred Stock offering to fund a portion of the Merger and to pay related fees and expenses. Dividends. The Series A Preferred Stock accrue cumulative dividends, calculated as a percentage of the stated amount per share, at a fixed annual rate of 6.125% per annum to, but excluding, September 1, 2023, and at an annual rate of three-month LIBOR plus a spread of 3.270% thereafter to be paid in cash if, when and as declared. If declared, prior to September 1, 2023, dividends are payable semi-annually in arrears on each March 1 and September 1, beginning on March 1, 2019, and, for the period commencing on September 1, 2023, dividends are payable quarterly in arrears each March 1, June 1, September 1 and December 1, beginning on December 1, 2023. Cumulative dividends earned during the applicable periods are presented on CenterPoint Energy’s Statements of Consolidated Income as Preferred stock dividend requirement. Optional Redemption. On or after September 1, 2023, CenterPoint Energy may, at its option, redeem the Series A Preferred Stock, in whole or in part, at any time or from time to time, for cash at a redemption price of $1,000 per share, plus any accumulated and unpaid dividends thereon to, but excluding, the redemption date. At any time within 120 days after the conclusion of any review or appeal process instituted by CenterPoint Energy, if any, following the occurrence of a ratings event, CenterPoint Energy may, at its option, redeem the Series A Preferred Stock in whole, but not in part, at a redemption price in cash per share equal to $1,020 ( 102% of the liquidation value of $1,000 ) plus an amount equal to all accumulated and unpaid dividends thereon to, but excluding, the redemption date, whether or not declared. Ranking. The Series A Preferred Stock, with respect to anticipated dividends and distributions upon CenterPoint Energy’s liquidation or dissolution, or winding-up of CenterPoint Energy’s affairs, ranks or will rank: • senior to Common Stock and to each other class or series of capital stock established after the initial issue date of the Series A Preferred Stock that is expressly made subordinated to the Series A Preferred Stock; • on a parity with any class or series of capital stock established after the initial issue date of the Series A Preferred Stock that is not expressly made senior or subordinated to the Series A Preferred Stock, including the Series B Preferred Stock; • junior to any class or series of capital stock established after the initial issue date of the Series A Preferred Stock that is expressly made senior to the Series A Preferred Stock; • junior to all existing and future indebtedness (including indebtedness outstanding under CenterPoint Energy’s credit facilities, senior notes and commercial paper) and other liabilities with respect to assets available to satisfy claims against CenterPoint Energy; and • structurally subordinated to any existing and future indebtedness and other liabilities of CenterPoint Energy’s subsidiaries and capital stock of CenterPoint Energy’s subsidiaries held by third parties. Voting Rights. Holders of the Series A Preferred Stock generally will not have voting rights. Whenever dividends on shares of Series A Preferred Stock have not been declared and paid for the equivalent of three or more semi-annual or six or more quarterly dividend periods (including, for the avoidance of doubt, the dividend period beginning on, and including, the original issue date and ending on, but excluding, March 1, 2019), whether or not consecutive, the holders of such shares of Series A Preferred Stock, voting together as a single class with holders of any and all other series of voting preferred stock (as defined in the Statement of Resolution for the Series A Preferred Stock) then outstanding, will be entitled at CenterPoint Energy’s next annual or special meeting of shareholders to vote for the election of a total of two additional members of CenterPoint Energy’s Board of Directors, subject to certain limitations. This right will terminate if and when all accumulated dividends have been paid in full and, upon such termination, the term of office of each director so elected will terminate at such time and the number of directors on CenterPoint Energy’s Board of Directors will automatically decrease by two, subject to the revesting of such rights in the event of each subsequent nonpayment. Series B Preferred Stock On October 1, 2018, CenterPoint Energy completed the issuance of 19,550,000 depositary shares, each representing a 1/20th interest in a share of its Series B Preferred Stock, at a price of $50 per depositary share, resulting in net proceeds of $950 million after issuance costs. The aggregate liquidation value of Series B Preferred Stock is $978 million with a per share liquidation value of $1,000 . The amount issued included 2,550,000 depositary shares issued pursuant to the exercise in full of the option granted to the underwriters to purchase additional depositary shares. CenterPoint Energy used the net proceeds from the offering of depositary shares, each representing a 1/20th interest in a share of its Series B Preferred Stock, to fund a portion of the Merger and to pay related fees and expenses. Dividends. Dividends on the Series B Preferred Stock will be payable on a cumulative basis when, as and if declared at an annual rate of 7.00% on the liquidation value of $1,000 per share. CenterPoint Energy may pay declared dividends in cash or, subject to certain limitations, in shares of Common Stock, or in any combination of cash and shares of Common Stock on March 1, June 1, September 1 and December 1 of each year, commencing on December 1, 2018 and ending on, and including, September 1, 2021. Cumulative dividends earned during the applicable periods are presented on CenterPoint Energy’s Statements of Consolidated Income as Preferred stock dividend requirement. Mandatory Conversion. Unless earlier converted or redeemed, each share of the Series B Preferred Stock will automatically convert on the mandatory conversion date, which is expected to be September 1, 2021, into not less than 30.5820 and not more than 36.6980 shares of Common Stock, subject to certain anti-dilution adjustments. Correspondingly, the conversion rate per depositary share will be not less than 1.5291 and not more than 1.8349 shares of Common Stock, subject to certain anti-dilution adjustments. The conversion rate will be determined based on a preceding 20-day volume-weighted-average-price of Common Stock. The following table illustrates the conversion rate per share of the Series B Preferred Stock, subject to certain anti-dilution adjustments: Applicable Market Value of the Common Stock Conversion Rate per Share of Series B Preferred Stock Greater than $32.6990 (threshold appreciation price) 30.5820 shares of Common Stock Equal to or less than $32.6990 but greater than or equal to $27.2494 Between 30.5820 and 36.6980 shares of Common Stock, determined by dividing $1,000 by the applicable market value Less than $27.2494 (initial price) 36.6980 shares of Common Stock The following table illustrates the conversion rate per depositary share, subject to certain anti-dilution adjustments: Applicable Market Value of the Common Stock Conversion Rate per Depository Share Greater than $32.6990 (threshold appreciation price) 1.5291 shares of Common Stock Equal to or less than $32.6990 but greater than or equal to $27.2494 Between 1.5291 and 1.8349 shares of Common Stock, determined by dividing $50 by the applicable market value Less than $27.2494 (initial price) 1.8349 shares of Common Stock Optional Conversion of the Holder. Other than during a fundamental change conversion period, and unless CenterPoint Energy has redeemed the Series B Preferred Stock, a holder of the Series B Preferred Stock may, at any time prior to September 1, 2021, elect to convert such holder’s shares of the Series B Preferred Stock, in whole or in part, at the minimum conversion rate of 30.5820 shares of Common Stock per share of the Series B Preferred Stock (equivalent to 1.5291 shares of Common Stock per depositary share), subject to certain anti-dilution and other adjustments. Because each depositary share represents a 1/20th fractional interest in a share of the Series B Preferred Stock, a holder of depositary shares may convert its depositary shares only in lots of 20 depositary shares. Fundamental Change Conversion. If a fundamental change occurs on or prior to September 1, 2021, holders of the Series B Preferred Stock will have the right to convert their shares of the Series B Preferred Stock, in whole or in part, into shares of Common Stock at the fundamental change conversion rate during the period beginning on, and including, the effective date of such fundamental change and ending on, and including, the date that is 20 calendar days after such effective date (or, if later, the date that is 20 calendar days after holders receive notice of such fundamental change, but in no event later than September 1, 2021). Holders who convert shares of the Series B Preferred Stock during that period will also receive a make-whole dividend amount comprised of a fundamental change dividend make-whole amount, and to the extent there is any, the accumulated dividend amount. Because each depositary share represents a 1/20th fractional interest in a share of the Series B Preferred Stock, a holder of depositary shares may convert its depositary shares upon a fundamental change only in lots of 20 depositary shares. Ranking. The Series B Preferred Stock, with respect to anticipated dividends and distributions upon CenterPoint Energy’s liquidation or dissolution, or winding-up of CenterPoint Energy’s affairs, ranks or will rank: • senior to Common Stock and to each other class or series of capital stock established after the initial issue date of the Series B Preferred Stock that is expressly made subordinated to the Series B Preferred Stock; • on a parity with the Series A Preferred Stock and any class or series of capital stock established after the initial issue date that is not expressly made senior or subordinated to the Series B Preferred Stock; • junior to any class or series of capital stock established after the initial issue date that is expressly made senior to the Series B Preferred Stock; • junior to all existing and future indebtedness (including indebtedness outstanding under CenterPoint Energy’s credit facilities, senior notes and commercial paper) and other liabilities with respect to assets available to satisfy claims against CenterPoint Energy; and • structurally subordinated to any existing and future indebtedness and other liabilities of CenterPoint Energy’s subsidiaries and capital stock of CenterPoint Energy’s subsidiaries held by third parties. Voting Rights. Holders of the Series B Preferred Stock generally will not have voting rights. Whenever dividends on shares of the Series B Preferred Stock have not been declared and paid for six or more dividend periods (including, for the avoidance of doubt, the dividend period beginning on, and including, the initial issue date and ending on, but excluding, December 1, 2018), whether or not consecutive, the holders of such shares of Series B Preferred Stock, voting together as a single class with holders of any and all other series of voting preferred stock then outstanding (as defined in the Statement of Resolution for the Series B Preferred Stock), will be entitled at CenterPoint Energy’s next annual or special meeting of shareholders to vote for the election of a total of two additional members of CenterPoint Energy’s Board of Directors, subject to certain limitations. This right will terminate if and when all accumulated and unpaid dividends have been paid in full and, upon such termination, the term of office of each director so elected will terminate at such time and the number of directors on CenterPoint Energy’s Board of Directors will automatically decrease by two, subject to the revesting of such rights in the event of each subsequent nonpayment. Common Stock On October 1, 2018, CenterPoint Energy completed the issuance of 69,633,027 shares of Common Stock at a price of $27.25 per share, for net proceeds of $1,844 million after issuance costs. The amount issued included 9,082,568 shares of Common Stock issued pursuant to the exercise in full of the option granted to the underwriters to purchase additional shares of Common Stock. CenterPoint Energy used the net proceeds from the Common Stock offering to fund a portion of the Merger and to pay related fees and expenses. Undistributed Retained Earnings As of December 31, 2019 and 2018 , CenterPoint Energy’s consolidated retained earnings balance includes undistributed earnings from Enable of $-0- and $31 million, respectively. Accumulated Other Comprehensive Income (Loss) Changes in accumulated comprehensive income (loss) are as follows: Year Ended December 31, 2019 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Beginning Balance $ (108 ) $ (14 ) $ 5 $ (68 ) $ — $ 6 Other comprehensive income (loss) before reclassifications: Remeasurement of pension and other postretirement plans 7 — 7 (19 ) — 1 Deferred loss from interest rate derivatives (1) (3 ) (1 ) — (19 ) (18 ) (1 ) Reclassified to earnings 1 — — — — — Other comprehensive loss from unconsolidated affiliates (1 ) — — — — — Amounts reclassified from accumulated other comprehensive loss: Prior service cost (2) 1 — — 1 — 1 Actuarial losses (2) 8 — — 6 — — Tax benefit (expense) (3 ) — (2 ) 6 4 (1 ) Net current period other comprehensive income (loss) 10 (1 ) 5 (25 ) (14 ) — Adoption of ASU 2018-02 — — — (15 ) — (1 ) Ending Balance $ (98 ) $ (15 ) $ 10 $ (108 ) $ (14 ) $ 5 (1) Gains and losses are reclassified from Accumulated other comprehensive income into income when the hedged transactions affect earnings. The reclassification amounts are included in Interest and other finance charges in each of the Registrant’s respective Statements of Consolidated Income. Amounts are $1 million and less than $1 million for the years ended December 31, 2019 and 2018 , respectively. (2) Amounts are included in the computation of net periodic cost and are reflected in Other, net in each of the Registrants’ respective Statements of Consolidated Income.

Short Term Borrowings and Long

Short Term Borrowings and Long Term Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Short-term Borrowings and Long-term Debt [Text Block]	Short-term Borrowings and Long-term Debt December 31, December 31, Long-Term Current (1) Long-Term Current (1) (in millions) CenterPoint Energy: ZENS due 2029 (2) $ — $ 19 $ — $ 24 Senior notes 2.50% to 7.08% due 2020 to 2049 (3) 3,728 100 2,000 — Variable rate term loans 2.275% to 2.56% due 2020 to 2021 1,000 500 — — First mortgage bonds 2.19% to 6.72% due 2022 to 2055 (4) 293 — — — Pollution control bonds 5.125% due 2028 (5) 68 — 68 — Commercial paper (6) (7) 1,901 — — — Unamortized debt issuance costs (22 ) — (13 ) — Unamortized discount and premium, net (7 ) — (2 ) — Houston Electric debt (see details below) 4,719 231 4,258 458 CERC debt (see details below) 2,546 — 2,371 — Other debt 18 18 — — Total CenterPoint Energy debt $ 14,244 $ 868 $ 8,682 $ 482 December 31, December 31, Long-Term Current (1) Long-Term Current (1) (in millions) Houston Electric: First mortgage bonds 9.15% due 2021 $ 102 $ — $ 102 $ — General mortgage bonds 1.85% to 6.95% due 2021 to 2049 3,912 — 3,212 — Restoration Bond Company: System restoration bonds 4.243% due 2022 134 62 197 59 Bond Company II: Transition bonds 5.302% due 2019 — — — 208 Bond Company III: Transition bonds 5.234% due 2020 — 29 29 56 Bond Company IV: Transition bonds 2.161% to 3.028% due 2020 to 2024 613 140 753 135 Unamortized debt issuance costs (27 ) — (24 ) — Unamortized discount and premium, net (15 ) — (11 ) — Total Houston Electric debt $ 4,719 $ 231 $ 4,258 $ 458 December 31, December 31, Long-Term Current (1) Long-Term Current (1) (in millions) CERC (8) : Senior notes 3.55% to 6.625% due 2021 to 2047 $ 2,193 $ — $ 2,193 $ — Commercial paper (6) 377 — 210 — Unamortized debt issuance costs (13 ) — (15 ) — Unamortized discount and premium, net (11 ) — (17 ) — Total CERC debt $ 2,546 $ — $ 2,371 $ — (1) Includes amounts due or exchangeable within one year of the date noted. (2) CenterPoint Energy’s ZENS obligation is bifurcated into a debt component and an embedded derivative component. For additional information regarding ZENS, see Note 12(b). As ZENS are exchangeable for cash at any time at the option of the holders, these notes are classified as a current portion of long-term debt. (3) Includes $532 million of senior notes issued by VUHI and $96 million of senior notes issued by Indiana Gas. The senior notes have stated interest rates that range from 3.72% to 7.08% . The senior notes issued by VUHI are guaranteed by SIGECO, Indiana Gas and VEDO. In connection with the Merger, two of CenterPoint Energy’s acquired wholly-owned subsidiaries, VUHI and VCC, made offers to prepay certain outstanding guaranteed senior notes as required pursuant to certain note purchase agreements previously entered into by VUHI and VCC. In turn, VUHI and VCC borrowed $568 million and $191 million , respectively, from CenterPoint Energy to fund note redemptions of senior notes effected pursuant to these prepayment offers. To fund these prepayments and payments of approximately $5 million of accrued interest, CenterPoint Energy issued approximately $764 million of commercial paper. (4) The first mortgage bonds issued by SIGECO subject SIGECO’s properties to a lien under the related mortgage indenture. (5) $68 million and $68 million of these series of debt were secured by general mortgage bonds of Houston Electric as of December 31, 2019 and 2018 , respectively. These general mortgage bonds are not reflected in Houston Electric’s consolidated financial statements because of the contingent nature of the obligations. (6) Classified as long-term debt because the termination date of the facility that backstops the commercial paper is more than one year from the date noted. (7) Commercial paper issued by VUHI has maturities up to 30 days. (8) Issued by CERC Corp. Long-term Debt Debt Retirements. During the year ended December 31, 2019, CenterPoint Energy retired the following debt instruments: Retirement Date Debt Instrument Aggregate Principal Amount Interest Rate Maturity Date (in millions) CenterPoint Energy December 2019 Guaranteed senior notes $ 3 3.33% 2022 CenterPoint Energy December 2019 Guaranteed senior notes 6 4.53% 2025 In December 2019, VCC redeemed the aggregate principal amount of its guaranteed senior notes at a redemption price equal to 100% of the principal amount thereof, plus accrued and unpaid interest thereon to but excluding the redemption date, plus the make-whole premium. The make-whole premium associated with the two redemptions was approximately $1 million and was included in Other Income, net on CenterPoint Energy’s Statements of Consolidated Income. Debt Transactions. During the year ended December 31, 2019 , the following debt instruments were issued or incurred: Issuance Date Debt Instrument Aggregate Principal Amount Interest Rate as of December 31, 2019 Maturity Date (in millions) Houston Electric January 2019 General mortgage bonds $ 700 4.25% 2049 CenterPoint Energy (1) February 2019 Variable rate term loan 25 2.275% 2020 CenterPoint Energy May 2019 Variable rate term loan 1,000 2.56% 2021 CenterPoint Energy August 2019 Unsecured senior notes 500 2.50% 2024 CenterPoint Energy August 2019 Unsecured senior notes 400 2.95% 2030 CenterPoint Energy August 2019 Unsecured senior notes 300 3.70% 2049 (1) Draw down by VCC on its variable rate term loan. Securitization Bonds. As of December 31, 2019 , CenterPoint Energy and Houston Electric had special purpose subsidiaries consisting of the Bond Companies, which they consolidate. The consolidated special purpose subsidiaries are wholly-owned, bankruptcy remote entities that were formed solely for the purpose of purchasing and owning transition or system restoration property through the issuance of transition bonds or system restoration bonds and activities incidental thereto. These Securitization Bonds are payable only through the imposition and collection of “transition” or “system restoration” charges, as defined in the Texas Public Utility Regulatory Act, which are irrevocable, non-bypassable charges to provide recovery of authorized qualified costs. CenterPoint Energy and Houston Electric have no payment obligations in respect of the Securitization Bonds other than to remit the applicable transition or system restoration charges they collect as set forth in servicing agreements among Houston Electric, the Bond Companies and other parties. Each special purpose entity is the sole owner of the right to impose, collect and receive the applicable transition or system restoration charges securing the bonds issued by that entity. Creditors of CenterPoint Energy or Houston Electric have no recourse to any assets or revenues of the Bond Companies (including the transition and system restoration charges), and the holders of Securitization Bonds have no recourse to the assets or revenues of CenterPoint Energy or Houston Electric. Credit Facilities. The Registrants had the following revolving credit facilities as of December 31, 2019 : Execution Date Registrant Size of Facility Draw Rate of LIBOR plus (1) Financial Covenant Limit on Debt for Borrowed Money to Capital Ratio Debt for Borrowed Money to Capital Ratio as of December 31, 2019 (2) Termination Date (in millions) March 3, 2016 CenterPoint Energy $ 3,300 1.500% 65% (3) 59.0% March 3, 2022 July 14, 2017 CenterPoint Energy (4) 400 1.125% 65% 51.6% July 14, 2022 July 14, 2017 CenterPoint Energy (5) 200 1.250% 65% 58.0% July 14, 2022 March 3, 2016 Houston Electric 300 1.125% 65% (3) 50.2% March 3, 2022 March 3, 2016 CERC 900 1.250% 65% 46.4% March 3, 2022 Total $ 5,100 (1) Based on credit ratings as of December 31, 2019 . (2) As defined in the revolving credit facility agreement, excluding Securitization Bonds. (3) For CenterPoint Energy and Houston Electric, the financial covenant limit will temporarily increase from 65% to 70% if Houston Electric experiences damage from a natural disaster in its service territory and CenterPoint Energy certifies to the administrative agent that Houston Electric has incurred system restoration costs reasonably likely to exceed $100 million in a consecutive 12 -month period, all or part of which Houston Electric intends to seek to recover through securitization financing. Such temporary increase in the financial covenant would be in effect from the date CenterPoint Energy delivers its certification until the earliest to occur of (i) the completion of the securitization financing, (ii) the first anniversary of CenterPoint Energy’s certification or (iii) the revocation of such certification. (4) This credit facility was issued by VUHI, is guaranteed by SIGECO, Indiana Gas and VEDO and includes a $10 million swing line sublimit and a $20 million letter of credit sublimit. This credit facility backstops VUHI’s commercial paper program. (5) This credit facility was issued by VCC, is guaranteed by Vectren and includes a $40 million swing line sublimit and an $80 million letter of credit sublimit. The Registrants, as well as the subsidiaries of CenterPoint Energy discussed above, were in compliance with all financial debt covenants as of December 31, 2019 . As of December 31, 2019 and 2018 , the Registrants had the following revolving credit facilities and utilization of such facilities: December 31, 2019 December 31, 2018 Registrant Loans Letters Commercial Weighted Average Interest Rate Loans Letters Commercial Weighted Average Interest Rate (in millions, except weighted average interest rate) CenterPoint Energy (1) $ — $ 6 $ 1,633 1.95 % $ — $ 6 $ — — % CenterPoint Energy (2) — — 268 2.08 % — — — — % CenterPoint Energy (3) — — — — % — — — — % Houston Electric — — — — % — 4 — — % CERC — 1 377 1.94 % — 1 210 2.93 % Total $ — $ 7 $ 2,278 $ — $ 11 $ 210 (1) CenterPoint Energy’s outstanding commercial paper generally has maturities of 60 days or less. (2) This credit facility was issued by VUHI and is guaranteed by SIGECO, Indiana Gas and VEDO. (3) This credit facility was issued by VCC and is guaranteed by Vectren. In January 2019, CenterPoint Energy issued the following commercial paper in connection with the closing of the Merger: Registrant Issuance Date Debt Instrument Aggregate Principal Amount Weighted Average Interest Rate (in millions) CenterPoint Energy (1) (2) January 2019 Commercial paper $ 1,660 2.88% (1) Proceeds from these commercial paper issuances were used to fund a portion of the Merger and to pay related fees and expenses and were contributed to Vectren for its payment of its stub period cash dividend, long-term incentive payments and to fund the repayment of indebtedness of Vectren subsidiaries redeemed at the option of the holder as a result of the closing of the Merger. (2) The commercial paper notes were issued at various times in January 2019 with maturities up to and including 90 days as of the time of issuance, and, prior to their use as described in connection with the closing of the Merger, the net proceeds of such issuances were invested in short-term investments. Maturities. As of December 31, 2019 , maturities of long-term debt, capital leases and sinking fund requirements, excluding the ZENS obligation, are as follows: CenterPoint Energy (1) Houston Electric (1) CERC Securitization Bonds (in millions) 2020 $ 831 $ 231 $ — $ 231 2021 2,761 613 593 211 2022 3,302 519 376 219 2023 713 356 300 156 2024 1,184 162 — 162 (1) These maturities include Securitization Bonds principal repayments on scheduled payment dates. Liens. As of December 31, 2019 , Houston Electric’s assets were subject to liens securing approximately $102 million of first mortgage bonds. Sinking or improvement fund and replacement fund requirements on the first mortgage bonds may be satisfied by certification of property additions. Sinking fund and replacement fund requirements for 2019 , 2018 and 2017 have been satisfied by certification of property additions. The replacement fund requirement to be satisfied in 2020 is approximately $295 million , and the sinking fund requirement to be satisfied in 2020 is approximately $1.6 million . CenterPoint Energy expects Houston Electric to meet these 2020 obligations by certification of property additions. As of December 31, 2019 , Houston Electric’s assets were also subject to liens securing approximately $4.0 billion of general mortgage bonds, including approximately $68 million held in trust to secure pollution control bonds for which CenterPoint Energy is obligated. The lien of the general mortgage indenture is junior to that of the mortgage pursuant to which the first mortgage bonds are issued. Houston Electric may issue additional general mortgage bonds on the basis of retired bonds, 70% of property additions or cash deposited with the trustee. Approximately $3.7 billion of additional first mortgage bonds and general mortgage bonds could be issued on the basis of retired bonds and 70% of property additions as of December 31, 2019 . Houston Electric has contractually agreed that it will not issue additional first mortgage bonds, subject to certain exceptions. Other. As of December 31, 2019 , certain financial institutions agreed to issue, from time to time, up to $50 million of letters of credit on behalf of Vectren and certain of its subsidiaries in exchange for customary fees. These agreements to issue letters of credit expire on December 31, 2020. As of December 31, 2019, such financial institutions had issued $21 million

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes [Text Block]	Income Taxes The components of the Registrant’ income tax expense (benefit) were as follows: Year Ended December 31, 2019 2018 2017 (in millions) CenterPoint Energy Current income tax expense: Federal $ 48 $ 89 $ 32 State 21 9 9 Total current expense 69 98 41 Deferred income tax expense (benefit): Federal 74 (25 ) (806 ) State (5 ) 73 36 Total deferred expense (benefit) 69 48 (770 ) Total income tax expense (benefit) $ 138 $ 146 $ (729 ) Houston Electric Current income tax expense: Federal $ 84 $ 109 $ 70 State 20 18 19 Total current expense 104 127 89 Deferred income tax benefit: Federal (24 ) (38 ) (98 ) Total deferred benefit (24 ) (38 ) (98 ) Total income tax expense (benefit) $ 80 $ 89 $ (9 ) CERC - Continuing Operations Current income tax expense (benefit): Federal $ — $ (9 ) $ (31 ) State 7 — (10 ) Total current expense (benefit) 7 (9 ) (41 ) Deferred income tax expense (benefit): Federal 39 10 (249 ) State (32 ) 21 25 Total deferred expense (benefit) 7 31 (224 ) Total income tax expense (benefit) $ 14 $ 22 $ (265 ) CERC - Discontinued Operations Current income tax expense (benefit): Federal $ — $ 9 $ 31 State — 4 11 Total current expense (benefit) — 13 42 Deferred income tax expense: Federal — 29 56 State — 4 6 Total deferred expense — 33 62 Total income tax expense $ — $ 46 $ 104 A reconciliation of income tax expense (benefit) using the federal statutory income tax rate to the actual income tax expense and resulting effective income tax rate is as follows: Year Ended December 31, 2019 2018 2017 (in millions) CenterPoint Energy (1) (2) (3) Income before income taxes $ 929 $ 514 $ 1,063 Federal statutory income tax rate 21 % 21 % 35 % Expected federal income tax expense 195 108 372 Increase (decrease) in tax expense resulting from: State income tax expense, net of federal income tax 36 22 26 State valuation allowance, net of federal income tax (4 ) 11 3 State law change, net of federal income tax (21 ) 32 — Federal income tax rate reduction — — (1,113 ) Excess deferred income tax amortization (55 ) (24 ) — Other, net (13 ) (3 ) (17 ) Total (57 ) 38 (1,101 ) Total income tax expense (benefit) $ 138 $ 146 $ (729 ) Effective tax rate 15 % 28 % (69 )% Houston Electric (4) (5) (6) Income before income taxes $ 436 $ 425 $ 424 Federal statutory income tax rate 21 % 21 % 35 % Expected federal income tax expense 92 89 148 Increase (decrease) in tax expense resulting from: State income tax expense, net of federal income tax 16 14 12 Federal income tax rate reduction — — (158 ) Excess deferred income tax amortization (21 ) (9 ) — Other, net (7 ) (5 ) (11 ) Total (12 ) — (157 ) Total income tax expense (benefit) $ 80 $ 89 $ (9 ) Effective tax rate 18 % 21 % (2 )% CERC - Continuing Operations (7) (8) (9) Income before income taxes $ 226 $ 92 $ 319 Federal statutory income tax rate 21 % 21 % 35 % Expected federal income tax expense 47 19 112 Increase (decrease) in tax expense resulting from: State income tax expense, net of federal income tax (12 ) 5 6 State law change, net of federal income tax (4 ) — — State valuation allowance, net of federal income tax (4 ) 11 3 Federal income tax rate reduction — — (396 ) Goodwill impairment 8 — — Excess deferred income tax amortization (18 ) (15 ) — Tax basis balance sheet adjustment — — 11 Other, net (3 ) 2 (1 ) Total (33 ) 3 (377 ) Total income tax expense (benefit) $ 14 $ 22 $ (265 ) Effective tax rate 6 % 24 % (83 )% Year Ended December 31, 2019 2018 2017 (in millions) CERC - Discontinued Operations (9) Income before income taxes $ — $ 184 $ 265 Federal statutory income tax rate — % 21 % 35 % Expected federal income tax expense — 39 93 Increase in tax expense resulting from: State income tax expense, net of federal income tax — 7 11 Total — 7 11 Total income tax expense $ — $ 46 $ 104 Effective tax rate — % 25 % 39 % (1) Recognized a $55 million benefit for the amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions, a $21 million net benefit for the impact of state law changes that resulted in the remeasurement of state deferred taxes in those jurisdictions, and $4 million net benefit for the reduction in valuation allowances on certain state net operating losses that are now expected to be realized. (2) Recognized a $32 million deferred tax expense due to state law changes that resulted in remeasurement of state deferred taxes in those jurisdictions. Also recorded an additional $11 million valuation allowance on certain state net operating loss deferred tax assets that are no longer expected to be utilized prior to expiration after the Internal Spin. These items are partially offset by $24 million of amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions beginning in 2018. (3) Recognized a $1.1 billion deferred tax benefit from the remeasurement of CenterPoint Energy’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% . (4) Recognized $21 million of amortization of the net regulatory EDIT liability as decreed by regulators. (5) Recognized $9 million of amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions beginning in 2018. (6) Recognized a $158 million deferred tax benefit from the remeasurement of Houston Electric’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% . (7) Recognized $18 million benefit for the amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions, $4 million net benefit for the impact of state law changes that resulted in the remeasurement of state deferred taxes in those jurisdictions and $4 million net benefit for the reduction in valuation allowances on certain state net operating losses that are now expected to be realized. (8) Recorded an additional $11 million valuation allowance on certain state net operating loss deferred tax assets that are no longer expected to be utilized prior to expiration after the Internal Spin. This item is partially offset by $15 million of amortization of the net regulatory EDIT liability in certain jurisdictions as decreed by regulators beginning in 2018. (9) Recognized a $396 million deferred tax benefit from the remeasurement of CERC’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% . ASC 740 requires tax impacts of changes in tax laws or rates be reported in continuing operations. Therefore, CERC’s federal income tax benefit generated by the remeasurement of the ADFIT liability for Enable during 2017 and state law changes during 2016 associated with its investment in Enable are reported in continuing operations on CERC’s Statements of Consolidated Income. The ADFIT liability associated with CERC’s investment in Enable is reported as discontinued operations on CERC’s Consolidated Balance Sheets. The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities were as follows: December 31, 2019 2018 (in millions) CenterPoint Energy Deferred tax assets: Benefits and compensation $ 152 $ 160 Regulatory liabilities 447 356 Loss and credit carryforwards 111 84 Asset retirement obligations 89 62 Indexed debt securities derivative 34 — Other 40 29 Valuation allowance (25 ) (18 ) Total deferred tax assets 848 673 Deferred tax liabilities: Property, plant and equipment 2,656 1,894 Investment in unconsolidated affiliates 1,010 987 Regulatory assets 344 395 Investment in marketable securities and indexed debt 586 478 Indexed debt securities derivative — 27 Other 180 131 Total deferred tax liabilities 4,776 3,912 Net deferred tax liabilities $ 3,928 $ 3,239 Houston Electric Deferred tax assets: Regulatory liabilities $ 195 $ 205 Benefits and compensation 14 17 Asset retirement obligations 9 7 Other 7 12 Total deferred tax assets 225 241 Deferred tax liabilities: Property, plant and equipment 1,129 1,087 Regulatory assets 126 177 Total deferred tax liabilities 1,255 1,264 Net deferred tax liabilities $ 1,030 $ 1,023 CERC - Continuing Operations Deferred tax assets: Benefits and compensation $ 24 $ 27 Regulatory liabilities 144 150 Loss and credit carryforwards 183 259 Asset retirement obligations 80 54 Other 23 20 Valuation allowance (15 ) (18 ) Total deferred tax assets 439 492 Deferred tax liabilities: Property, plant and equipment 821 773 Regulatory assets 45 41 Other 43 84 Total deferred tax liabilities 909 898 Net deferred tax liabilities $ 470 $ 406 Merger with Vectren . On Merger Date, pursuant to the Merger Agreement, CenterPoint Energy consummated the Merger and acquired Vectren for approximately $6 billion in cash. On the Merger Date, Vectren became a wholly-owned subsidiary of CenterPoint Energy which triggered an ownership change under Section 382 of the Code. Under this Code section, future utilization of acquired net operating loss carry forwards and other tax attributes can be limited. On the Merger Date, Vectren estimated $177 million and $60 million of federal net operating loss and of charitable contribution carryforwards, respectively, the utilization of which is not expected to be limited under Section 382. Tax Attribute Carryforwards and Valuation Allowance . CenterPoint Energy has no federal net operating loss carryforwards as of December 31, 2019. Also, CenterPoint Energy has $26 million of federal charitable contribution carryforwards, which have a five-year carryover period. As of December 31, 2019, CenterPoint Energy had $699 million of state net operating loss carryforwards that expire between 2020 and 2039 and $21 million of state tax credits that do not expire. CenterPoint Energy reported a valuation allowance of $25 million because it is more likely than not that the benefit from certain state net operating loss carryforwards will not be realized. CERC has $618 million of federal net operating loss carryforwards which have an indefinite carryforward period. CERC has $691 million of state net operating loss carryforwards which expire between 2020 and 2039 and $17 million of state tax credits which do not expire. CERC reported a valuation allowance of $15 million since it is more likely than not that the benefit from certain state net operating loss carryforwards will not be realized. A reconciliation of CenterPoint Energy’s beginning and ending balance of unrecognized tax benefits, excluding interest and penalties, for 2019 is as follows: Year Ended December 31, 2019 (in millions) Balance, beginning of year $ — Unrecognized tax benefits assumed through the Merger 9 Decreases related to tax positions of prior years (1 ) Balance, end of year $ 8 CenterPoint Energy had no unrecognized tax benefits for 2018 and 2017. During the year ended December 31, 2019, CenterPoint Energy acquired $9 million of unrecognized tax benefits in connection with the Merger. Included in the balance of uncertain tax positions as of December 31, 2019 are $3 million of tax benefits that, if recognized, would affect the effective tax rate. The above table does not include an immaterial amount of accrued interest as of December 31, 2019. The Registrants recognize interest accrued related to unrecognized tax benefits and penalties as income tax expense. The Registrants believe that it is reasonably possible that a decrease of up to $5 million in unrecognized tax benefits may occur by the end of 2020 as a result of a lapse of statutes on older exposures and/or the filing of applications for accounting method changes. CenterPoint Energy’s net unrecognized tax benefits, including penalties and interest, were $9 million as of December 31, 2019 and are included in other non-current liabilities in the Consolidated Financial Statements. Tax Audits and Settlements . Tax years through 2017 have been audited and settled with the IRS for CenterPoint Energy. For the 2018 and 2019 tax years, the Registrants are participants in the IRS’s Compliance Assurance Process. Legacy Vectren is not currently under audit with the IRS, and the 2017-2019 tax years are still open.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies [Text Block]	Commitments and Contingencies (a) Purchase Obligations (CenterPoint Energy and CERC) Commitments include minimum purchase obligations related to CenterPoint Energy’s and CERC’s Natural Gas Distribution and Energy Services reportable segments and CenterPoint Energy’s Indiana Electric Integrated reportable segment. Contracts with minimum payment provisions have various quantity requirements and durations and are not classified as non-trading derivative assets and liabilities in CenterPoint Energy’s and CERC’s Consolidated Balance Sheets as of December 31, 2019 and 2018 . These contracts meet an exception as “normal purchases contracts” or do not meet the definition of a derivative. Natural gas and coal supply commitments also include transportation contracts that do not meet the definition of a derivative. As of December 31, 2019 , minimum purchase obligations are approximately: CenterPoint Energy CERC (in millions) 2020 $ 750 $ 533 2021 617 432 2022 418 242 2023 335 182 2024 271 174 2025 and beyond 1,888 1,526 Indiana Electric also has other purchased power agreements that do not have minimum thresholds but do require payment when energy is generated by the provider. Costs arising from certain of these commitments are pass-through costs, generally collected dollar-for-dollar from retail customers through regulator-approved cost recovery mechanisms. (b) AMAs (CenterPoint Energy and CERC) CenterPoint Energy’s and CERC’s NGD has AMAs associated with their utility distribution service in Arkansas, Indiana, Louisiana, Mississippi, Oklahoma and Texas. The AMAs have varying terms, the longest of which expires in 2023. Pursuant to the provisions of the agreements, CenterPoint Energy’s and CERC’s NGD either sells natural gas to the asset manager and agrees to repurchase an equivalent amount of natural gas throughout the year at the same cost, or simply purchases its full natural gas requirements at each delivery point from the asset manager. Generally, AMAs are contracts between CenterPoint Energy’s and CERC’s NGD and an asset manager that are intended to transfer the working capital obligation and maximize the utilization of the assets. In these agreements, CenterPoint Energy’s and CERC’s NGD agrees to release transportation and storage capacity to other parties to manage natural gas storage, supply and delivery arrangements for CenterPoint Energy’s and CERC’s NGD and to use the released capacity for other purposes when it is not needed for CenterPoint Energy’s and CERC’s NGD. CenterPoint Energy’s and CERC’s NGD may receive compensation from the asset manager through payments made over the life of the AMAs. CenterPoint Energy’s and CERC’s NGD has an obligation to purchase their winter storage requirements that have been released to the asset manager under these AMAs. (c) Guarantees and Product Warranties (CenterPoint Energy) In the normal course of business, ESG enters into contracts requiring it to timely install infrastructure, operate facilities, pay vendors and subcontractors and support warranty obligations and, at times, issue payment and performance bonds and other forms of assurance in connection with these contracts. Specific to ESG’s role as a general contractor in the performance contracting industry, as of December 31, 2019 , there were 62 open surety bonds supporting future performance with an aggregate face amount of approximately $565 million . ESG’s exposure is less than the face amount of the surety bonds and is limited to the level of uncompleted work under the contracts. As of December 31, 2019 , approximately 36% of the work was yet to be completed on projects with open surety bonds. Further, various subcontractors issue surety bonds to ESG. In addition to these performance obligations, ESG also warrants the functionality of certain installed infrastructure generally for one year and the associated energy savings over a specified number of years. Since ESG’s inception in 1994, CenterPoint Energy believes ESG has had a history of generally meeting its performance obligations and energy savings guarantees and its installed products operating effectively. CenterPoint Energy assessed the fair value of its obligation for such guarantees as of December 31, 2019 and no amounts were recorded on CenterPoint Energy’s Consolidated Balance Sheets. CenterPoint Energy issues parent company level guarantees to certain vendors, customers and other commercial counterparties of ESG. These guarantees do not represent incremental consolidated obligations, but rather, represent guarantees of subsidiary obligations to allow those subsidiaries to conduct business without posting other forms of assurance. As of December 31, 2019 , CenterPoint Energy, primarily through Vectren, has issued parent company level guarantees supporting ESG’s obligations. For those obligations where potential exposure can be estimated, management estimates the maximum exposure under these guarantees to be approximately $499 million as of December 31, 2019 . This exposure primarily relates to energy savings guarantees on federal energy savings performance contracts. Other parent company level guarantees, certain of which do not contain a cap on potential liability, have been issued in support of federal operations and maintenance projects for which a maximum exposure cannot be estimated based on the nature of the projects. While there can be no assurance that performance under any of these parent company guarantees will not be required in the future, CenterPoint Energy considers the likelihood of a material amount being incurred as remote. (d) Guarantees and Product Warranties (CenterPoint Energy and CERC) In the normal course of business, CES trades natural gas under supply contracts and enters into natural gas related transactions under transportation, storage and other contracts. In connection with these CES business activities, CERC Corp. has issued guarantees to CES counterparties to guarantee the payment of CES obligations. While CES remains wholly-owned by CERC Corp., these guarantees do not represent incremental consolidated obligations, but rather, represent guarantees of CES’s obligations to allow CES to conduct business without posting other forms of assurance. As of December 31, 2019, the face amount of CERC Corp.’s guarantees of CES obligations was approximately $ 1.8 billion . A CERC Corp. guarantee primarily has a one- or two-year term, although CERC Corp. would generally not be released from obligations incurred by CES prior to the termination of such guarantee unless the beneficiary of the guarantee affirmatively released CERC Corp. from its obligations under the guarantee. Since CERC Corp. has owned CES, CERC Corp. has not paid any amounts under any guarantees of CES obligations. While there can be no assurance that performance under any of these parent company guarantees will not be required in the future, CenterPoint Energy and CERC consider the likelihood of a material amount being incurred as remote. On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment. Under the terms of the Equity Purchase Agreement, Athena Energy Services must generally use reasonable best efforts to replace existing CERC Corp. guarantees with credit support provided by a party other than CERC Corp. as of and after closing of the sale. Additionally, to the extent that CERC Corp. retains any exposure relating to the guarantees of CES obligations 90 days after closing, Athena Energy Services will pay a 3% annualized fee on such exposure, increasing by 1% on an annualized basis every three months. CenterPoint Energy and CERC recorded no amounts on their respective Consolidated Balance Sheets as of December 31, 2019 and 2018 related to these guarantees. (e) Legal, Environmental and Other Matters Legal Matters Gas Market Manipulation Cases (CenterPoint Energy and CERC) . CenterPoint Energy, its predecessor, Reliant Energy, and certain of their former subsidiaries were named as defendants in a large number of lawsuits filed against numerous gas market participants in a number of federal and western state courts in connection with the operation of the natural gas markets in 2000-2002. CenterPoint Energy and its affiliates were released or dismissed from all such cases, except for one case in federal court in Nevada in which CES, a subsidiary of CERC, was a defendant. Plaintiffs in that case alleged a conspiracy to inflate Wisconsin natural gas prices in 2000-2002. In October 2018, CES reached an agreement to settle all claims against CES and CES’s claims for indemnity. During the third quarter of 2019, the federal district court issued final approval of the settlement and dismissed the case, and CES completed the required settlement payments; the settlement agreement has now become final. This settlement did not have a material adverse effect on CenterPoint Energy’s or CERC’s financial condition, results of operations or cash flows. Minnehaha Academy (CenterPoint Energy and CERC). On August 2, 2017, a natural gas explosion occurred at the Minnehaha Academy in Minneapolis, Minnesota, resulting in the deaths of two school employees, serious injuries to others and significant property damage to the school. CenterPoint Energy, certain of its subsidiaries, including CERC, and the contractor company working in the school have been named in litigation arising out of this incident. CenterPoint Energy and CERC have reached confidential settlement agreements on all wrongful death and property damage claims and with some personal injury claimants. Additionally, CenterPoint Energy and CERC cooperated with the investigation conducted by the National Transportation Safety Board, which concluded its investigation in December 2019 and issued a report without making any recommendations. Further, CenterPoint Energy and CERC contested and reached a settlement regarding approximately $200,000 in fines imposed by the Minnesota Office of Pipeline Safety. In early 2018, the Minnesota Occupational Safety and Health Administration concluded its investigation without any adverse findings against CenterPoint Energy or CERC. CenterPoint Energy’s and CERC’s general and excess liability insurance policies provide coverage for third party bodily injury and property damage claims. Litigation Related to the Merger (CenterPoint Energy). With respect to the Merger, in July 2018, seven separate lawsuits were filed against Vectren and the individual directors of Vectren’s Board of Directors in the U.S. District Court for the Southern District of Indiana. These lawsuits alleged violations of Sections 14(a) of the Exchange Act and SEC Rule 14a-9 on the grounds that the Vectren Proxy Statement filed on June 18, 2018 was materially incomplete because it omitted material information concerning the Merger. In August 2018, the seven lawsuits were consolidated, and the Court denied the plaintiffs’ request for a preliminary injunction. In October 2018, the plaintiffs filed their Consolidated Amended Class Action Complaint. In December 2018, two plaintiffs voluntarily dismissed their lawsuits. In September 2019, the court granted the defendants’ motion to dismiss and dismissed the remaining plaintiffs’ claims with prejudice, which the plaintiffs appealed in October 2019. The defendants believe that the allegations asserted are without merit and intend to vigorously defend themselves against the claims raised. CenterPoint Energy does not expect the ultimate outcome of this matter to have a material adverse effect on its financial condition, results of operations or cash flows. Environmental Matters MGP Sites. CenterPoint Energy, CERC and their predecessors operated MGPs in the past. In addition, certain of CenterPoint Energy’s subsidiaries acquired through the Merger operated MGPs in the past. The costs CenterPoint Energy or CERC, as applicable, expect to incur to fulfill their respective obligations are estimated by management using assumptions based on actual costs incurred, the timing of expected future payments and inflation factors, among others. While CenterPoint Energy and CERC have recorded all costs which they presently are obligated to incur in connection with activities at these sites, it is possible that future events may require remedial activities which are not presently foreseen, and those costs may not be subject to PRP or insurance recovery. (i) Minnesota MGPs (CenterPoint Energy and CERC) . With respect to certain Minnesota MGP sites, CenterPoint Energy and CERC have completed state-ordered remediation and continue state-ordered monitoring and water treatment. CenterPoint Energy and CERC recorded a liability as reflected in the table below for continued monitoring and any future remediation required by regulators in Minnesota. (ii) Indiana MGPs (CenterPoint Energy) . In the Indiana Gas service territory, the existence, location and certain general characteristics of 26 gas manufacturing and storage sites have been identified for which CenterPoint Energy may have some remedial responsibility. A remedial investigation/feasibility study was completed at one of the sites under an agreed upon order between Indiana Gas and the IDEM, and a Record of Decision was issued by the IDEM in January 2000. The remaining sites have been submitted to the IDEM’s VRP. CenterPoint Energy has also identified its involvement in five manufactured gas plant sites in SIGECO’s service territory, all of which are currently enrolled in the IDEM’s VRP. CenterPoint Energy is currently conducting some level of remedial activities, including groundwater monitoring at certain sites. (iii) Other MGPs (CenterPoint Energy and CERC). In addition to the Minnesota and Indiana sites, the EPA and other regulators have investigated MGP sites that were owned or operated by CenterPoint Energy or CERC or may have been owned by one of their former affiliates. Total costs that may be incurred in connection with addressing these sites cannot be determined at this time. The estimated accrued costs are limited to CenterPoint Energy’s and CERC’s share of the remediation efforts and are therefore net of exposures of other PRPs. The estimated range of possible remediation costs for the sites for which CenterPoint Energy and CERC believe they may have responsibility was based on remediation continuing for the minimum time frame given in the table below. December 31, 2019 CenterPoint Energy CERC (in millions, except years) Amount accrued for remediation $ 12 $ 7 Minimum estimated remediation costs 7 4 Maximum estimated remediation costs 51 32 Minimum years of remediation 5 30 Maximum years of remediation 50 50 The cost estimates are based on studies of a site or industry average costs for remediation of sites of similar size. The actual remediation costs will depend on the number of sites to be remediated, the participation of other PRPs, if any, and the remediation methods used. CenterPoint Energy and CERC do not expect the ultimate outcome of these matters to have a material adverse effect on the financial condition, results of operations or cash flows of either CenterPoint Energy or CERC. Asbestos. Some facilities owned by the Registrants or their predecessors contain or have contained asbestos insulation and other asbestos-containing materials. The Registrants are from time to time named, along with numerous others, as defendants in lawsuits filed by a number of individuals who claim injury due to exposure to asbestos, and the Registrants anticipate that additional claims may be asserted in the future. Although their ultimate outcome cannot be predicted at this time, the Registrants do not expect these matters, either individually or in the aggregate, to have a material adverse effect on their financial condition, results of operations or cash flows. CCR Rule (CenterPoint Energy). In April 2015, the EPA finalized its CCR Rule, which regulates ash as non-hazardous material under the RCRA. The final rule allows beneficial reuse of ash, and the majority of the ash generated by Indiana Electric’s generating plants will continue to be reused. In July 2018, the EPA released its final CCR Rule Phase I Reconsideration which extended the deadline to October 31, 2020 for ceasing placement of ash in ponds that exceed groundwater protections standards or that fail to meet location restrictions. While the EPA Phase I Reconsideration moves forward, the existing CCR compliance obligations remain in effect. In August 2019, the EPA proposed additional amendments to its CCR Rule with respect to beneficial reuse of ash and other materials. The proposed revisions would not restrict Indiana Electric’s current beneficial reuse of its fly ash. Indiana Electric has three ash ponds, two at the F.B. Culley facility (Culley East and Culley West) and one at the A.B. Brown facility. Under the existing CCR Rule, Indiana Electric is required to perform integrity assessments, including ground water monitoring, at its F.B. Culley and A.B. Brown generating stations. The ground water studies are necessary to determine the remaining service life of the ponds and whether a pond must be retrofitted with liners or closed in place, with bottom ash handling conversions completed. Indiana Electric’s Warrick generating unit is not included in the scope of the CCR Rule as this unit has historically been part of a larger generating station that predominantly serves an adjacent industrial facility. In March 2018, Indiana Electric began posting ground water data monitoring reports annually to its public website in accordance with the requirements of the CCR Rule. This data preliminarily indicates potential groundwater impacts very close to Indiana Electric’s ash impoundments, and further analysis is ongoing. The CCR Rule required companies to complete location restriction determinations by October 18, 2018. Indiana Electric completed its evaluation and determined that one F.B. Culley pond (Culley East) and the A.B. Brown pond fail the aquifer placement location restriction. As a result of this failure, Indiana Electric is required to cease disposal of new ash in the ponds and commence closure of the ponds by October 31, 2020. CenterPoint Energy plans to seek extensions available under the CCR Rule that would allow Indiana Electric to continue to use the ponds through December 31, 2023. The inability to take these extensions may result in increased and potentially significant operational costs in connection with the accelerated implementation of an alternative ash disposal system or adversely impact Indiana Electric’s future operations. Failure to comply with these requirements could also result in an enforcement proceeding including the imposition of fines and penalties. On April 24, 2019, Indiana Electric received an order from the IURC approving recovery in rates of costs associated with the closure of the Culley West pond, which has already commenced closure activities. CenterPoint Energy believes the language in the IURC order is favorable for future recovery of closure costs for Indiana Electric’s remaining ponds. Indiana Electric continues to refine site specific estimates of closure costs. In July 2018, Indiana Electric filed a Complaint for Damages and Declaratory Relief against its insurers seeking reimbursement of defense, investigation and pond closure costs incurred to comply with the CCR Rule, and has since reached confidential settlement agreements with its insurers. The proceeds of these settlements will offset costs that have been and will be incurred to close the ponds. In March 2019, Indiana Electric entered into agreements with third parties for the excavation and beneficial reuse of the ash at the A.B. Brown ash pond. On August 14, 2019, Indiana Electric filed its petition with the IURC for recovery of costs associated with the closure of the A.B. Brown ash pond, which would include costs associated with the excavation and recycling of the ponded ash. On November 4, 2019, the EPA released a pre-publication copy of proposed revisions to the CCR Rule. CenterPoint Energy will evaluate the proposals to determine potential impacts to current compliance plans for its A.B. Brown and F.B. Culley generating stations. As of December 31, 2019 , CenterPoint Energy has recorded an approximate $68 million ARO, which represents the discounted value of future cash flow estimates to close the ponds at A.B. Brown and F.B. Culley. This estimate is subject to change due to the contractual arrangements; continued assessments of the ash, closure methods, and the timing of closure; implications of Indiana Electric’s generation transition plan; changing environmental regulations; and proceeds received from the settlements in the aforementioned insurance proceeding. In addition to these removal costs, Indiana Electric also anticipates equipment purchases of between $60 million and $80 million to complete the A.B. Brown closure project. Other Environmental. From time to time, the Registrants identify the presence of environmental contaminants during operations or on property where predecessors have conducted operations. Other such sites involving contaminants may be identified in the future. The Registrants have and expect to continue to remediate any identified sites consistent with state and federal legal obligations. From time to time, the Registrants have received notices, and may receive notices in the future, from regulatory authorities or others regarding status as a PRP in connection with sites found to require remediation due to the presence of environmental contaminants. In addition, the Registrants have been, or may be, named from time to time as defendants in litigation related to such sites. Although the ultimate outcome of such matters cannot be predicted at this time, the Registrants do not expect these matters, either individually or in the aggregate, to have a material adverse effect on their financial condition, results of operations or cash flows. Other Proceedings The Registrants are involved in other legal, environmental, tax and regulatory proceedings before various courts, regulatory commissions and governmental agencies regarding matters arising in the ordinary course of business. From time to time, the Registrants are also defendants in legal proceedings with respect to claims brought by various plaintiffs against broad groups of participants in the energy industry. Some of these proceedings involve substantial amounts. The Registrants regularly analyze current information and, as necessary, provide accruals for probable and reasonably estimable liabilities on the eventual disposition of these matters. The Registrants do not expect the disposition of these matters to have a material adverse effect on the Registrants’ financial condition, results of operations or cash flows.

Earnings Per Share (CenterPoint

Earnings Per Share (CenterPoint Energy)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share (CenterPoint Energy) [Text Block]	Earnings Per Share (CenterPoint Energy) The following table reconciles numerators and denominators of CenterPoint Energy’s basic and diluted earnings per common share. Basic earnings per common share is determined by dividing Income available to common shareholders - basic by the Weighted average common shares outstanding - basic for the applicable period. Diluted earnings per common share is determined by the inclusion of potentially dilutive common stock equivalent shares that may occur if securities to issue Common Stock were exercised or converted into Common Stock. For the Year Ended December 31, 2019 2018 2017 (in millions, except per share and share amounts) Numerator: Income available to common shareholders - basic (1) $ 674 $ 333 $ 1,792 Add back: Series B Preferred Stock dividend (2) — — — Income available to common shareholders - diluted (1) $ 674 $ 333 $ 1,792 Denominator: Weighted average common shares outstanding - basic 502,050,000 448,829,000 430,964,000 Plus: Incremental shares from assumed conversions: Restricted stock (3) 3,107,000 3,636,000 3,344,000 Series B Preferred Stock (2) — — — Weighted average common shares outstanding - diluted 505,157,000 452,465,000 434,308,000 Earnings per common share: Basic earnings per common share $ 1.34 $ 0.74 $ 4.16 Diluted earnings per common share $ 1.33 $ 0.74 $ 4.13 (1) Income available to common shareholders for the year ended December 31, 2019 includes net income from businesses acquired in the Merger of $190 million . See Note 4. Income available to common shareholders for the year ended December 31, 2017 includes a reduction in income tax expense of $1,113 million due to tax reform. See Note 15 for further discussion of the impacts of the TCJA. (2) The potentially dilutive impact from Series B Preferred Stock applies the if-converted method in calculating diluted earnings per common share. Under this method, diluted earnings per common share is adjusted for the more dilutive effect of the Series B Preferred Stock as a result of either its accumulated dividend for the period in the numerator or the assumed-converted common share equivalent in the denominator. The computation of diluted earnings per common share outstanding for the year ended December 31, 2019 and December 31, 2018 excludes Series B Stock Dividends of $ 68 million and $17 million , respectively, and 34,354,000 and 8,885,000 potentially dilutive shares, respectively, because to include them would be anti-dilutive. However, these shares could be potentially dilutive in the future. (3) The potentially dilutive impact from restricted stock awards applies the treasury stock method. Under this method, an increase in the average fair market value of Common Stock can result in a greater dilutive impact from these securities.

Unaudited Quarterly Information

Unaudited Quarterly Information	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Information [Text Block]	Unaudited Quarterly Information Summarized quarterly financial data is as follows: Year Ended December 31, 2019 First Quarter Second Quarter Third Quarter Fourth Quarter (in millions, except per share amounts) CenterPoint Energy Revenues $ 3,531 $ 2,798 $ 2,742 $ 3,230 Operating income 245 287 392 302 Income available to common shareholders 140 165 241 128 Basic earnings per common share (1) 0.28 0.33 0.48 0.25 Diluted earnings per common share (1) 0.28 0.33 0.47 0.25 Houston Electric Revenues 686 765 859 680 Operating income 81 169 269 99 Net income 27 100 185 44 CERC Revenues 2,368 1,342 1,126 1,734 Operating income 196 58 23 73 Net income (loss) 138 28 (7 ) 53 Year Ended December 31, 2018 First Quarter Second Third Quarter Fourth Quarter (in millions, except per share amounts) CenterPoint Energy Revenues $ 3,155 $ 2,186 $ 2,212 $ 3,036 Operating income 251 187 226 167 Income (loss) available to common shareholders 165 (75 ) 153 90 Basic earnings (loss) per common share (1) 0.38 (0.17 ) 0.35 0.18 Diluted earnings (loss) per common share (1) 0.38 (0.17 ) 0.35 0.18 Houston Electric Revenues 755 854 897 728 Operating income 119 181 227 98 Net income 52 101 143 40 CERC (2) Revenues 2,400 1,328 1,312 2,303 Operating income (loss) 131 22 (7 ) 76 Income (loss) from continuing operations 78 (8 ) (35 ) 35 Income (loss) from discontinued operations 52 44 44 (2 ) Net income 130 36 9 33 (1) Quarterly earnings (loss) per common share are based on the weighted average number of shares outstanding during the quarter, and the sum of the quarters may not equal annual earnings (loss) per common share. (2) Amounts have been recast to reflect discontinued operations in all periods presented.

Reportable Segments

Reportable Segments	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Reportable Segments [Text Block]	Reportable Segments The Registrants’ determination of reportable segments considers the strategic operating units under which the Registrants manage sales, allocate resources and assess performance of various products and services to wholesale or retail customers in differing regulatory environments. The Registrants use operating income as the measure of profit or loss for the reportable segments other than Midstream Investments, where equity in earnings is used. As of December 31, 2019 , reportable segments by Registrant are as follows: Registrants Houston Electric T&D Indiana Electric Integrated Natural Gas Distribution Energy Infrastructure Services Midstream Investments Corporate and Other CenterPoint Energy X X X X X X X Houston Electric X CERC X X X • CenterPoint Energy’s and Houston Electric’s Houston Electric T&D reportable segment consists of electric transmission and distribution services in the Texas Gulf Coast area. • CenterPoint Energy’s Indiana Electric Integrated reportable segment consists of electric transmission and distribution services primarily to southwestern Indiana and includes power generation and wholesale power operations. • CenterPoint Energy’s Natural Gas Distribution reportable segment consists of intrastate natural gas sales to, and natural gas transportation and distribution for residential, commercial, industrial and institutional customers in Arkansas, Indiana, Louisiana, Minnesota, Mississippi, Ohio, Oklahoma and Texas. • CERC’s Natural Gas Distribution reportable segment consists of intrastate natural gas sales to, and natural gas transportation and distribution for residential, commercial, industrial and institutional customers in Arkansas, Louisiana, Minnesota, Mississippi, Oklahoma and Texas. • CenterPoint Energy’s and CERC’s Energy Services reportable segment consists of non-rate regulated natural gas sales and services operations. • CenterPoint Energy’s Infrastructure Services reportable segment consists of underground pipeline construction and repair services. • CenterPoint Energy’s Midstream Investments reportable segment consists of the equity investment in Enable (excluding the Enable Series A Preferred Units). • CenterPoint Energy’s Corporate and Other reportable segment consists of energy performance contracting and sustainable infrastructure services through ESG and other corporate operations which support all of the business operations of CenterPoint Energy. • CERC’s Corporate and Other reportable segment consists primarily of corporate operations which support all of the business operations of CERC. On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Purchase Agreement to sell its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23 to the consolidated financial statements. Additionally, on February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. Expenditures for long-lived assets include property, plant and equipment. Intersegment sales are eliminated in consolidation, except as described in Note 2(b). Financial data for reportable segments and products and services are as follows: CenterPoint Energy Revenues from External Customers Net Intersegment Revenues Depreciation and Amortization Operating Income (Loss) Total Assets Expenditures for Long-Lived Assets (in millions) As of and for the year ended December 31, 2019: Houston Electric T&D $ 2,996 (1) $ — $ 648 $ 624 $ 11,264 $ 1,033 Indiana Electric Integrated 523 — 91 90 3,168 183 Natural Gas Distribution 3,643 40 417 408 13,903 1,098 Energy Services 3,653 129 16 32 1,301 12 Infrastructure Services 1,186 (2) 4 50 95 1,077 67 Midstream Investments (3) — — — — 2,473 — Corporate and Other 300 — 65 (23 ) 4,784 (4) 194 Eliminations — (173 ) — — (2,531 ) — Consolidated $ 12,301 $ — $ 1,287 $ 1,226 $ 35,439 $ 2,587 Reconciling items (81 ) Capital expenditures per Statements of Consolidated Cash Flows $ 2,506 As of and for the year ended December 31, 2018: Houston Electric T&D $ 3,232 (1) $ — $ 917 $ 623 $ 10,509 $ 952 Natural Gas Distribution 2,931 36 277 266 6,956 638 Energy Services 4,411 110 16 (47 ) 1,558 20 Midstream Investments (3) — — — — 2,482 — Corporate and Other 15 — 33 (11 ) 6,156 (4) 110 Eliminations — (146 ) — — (652 ) — Consolidated $ 10,589 $ — $ 1,243 $ 831 $ 27,009 $ 1,720 Reconciling items (69 ) Capital expenditures per Statements of Consolidated Cash Flows $ 1,651 As of and for the year ended December 31, 2017: Houston Electric T&D $ 2,997 (1) $ — $ 724 $ 636 $ 10,292 $ 924 Natural Gas Distribution 2,606 33 260 348 6,608 523 Energy Services 3,997 52 19 126 1,521 11 Midstream Investments (3) — — — — 2,472 — Corporate and Other 14 — 33 26 2,497 (4) 36 Eliminations — (85 ) — — (654 ) — Consolidated $ 9,614 $ — $ 1,036 $ 1,136 $ 22,736 $ 1,494 Reconciling items (68 ) Capital expenditures per Statements of Consolidated Cash Flows $ 1,426 (1) CenterPoint Energy’s Houston Electric T&D’s revenues from major customers are as follows: Year Ended December 31, 2019 2018 2017 (in millions) Affiliates of NRG $ 727 $ 705 $ 713 Affiliates of Vistra Energy Corp. 263 251 229 (2) Includes revenues not eliminated in consolidation for pipeline construction and repair services of $162 million capitalized by CenterPoint Energy’s NGD for the 11 months ended December 31, 2019. See Note 2(b). (3) CenterPoint Energy’s Midstream Investments’ equity earnings, net are as follows: Year Ended December 31, 2019 2018 2016 (in millions) Enable $ 229 $ 307 $ 265 (4) Total assets included pension and other postemployment-related regulatory assets of $584 million , $665 million and $600 million as of December 31, 2019 , 2018 and 2017 , respectively. Additionally, total assets as of December 31, 2018 included $3.9 billion of temporary investments included in Cash and cash equivalents on CenterPoint Energy’s Consolidated Balance Sheets. Houston Electric Houston Electric consists of a single reportable segment; therefore, a tabular reportable segment presentation has not been included. (1) Houston Electric’s revenues from major external customers are as follows: Year Ended December 31, 2019 2018 2017 (in millions) Affiliates of NRG $ 727 $ 705 $ 713 Affiliates of Vistra Energy Corp. 263 251 229 CERC Revenues from External Customers Net Intersegment Revenues Depreciation and Amortization Operating Income (Loss) Total Assets (1) Expenditures for Long-Lived Assets (in millions) As of and for the year ended December 31, 2019: Natural Gas Distribution $ 2,911 $ 40 $ 289 $ 316 $ 7,497 $ 773 Energy Services 3,654 128 16 32 1,301 12 Other Operations 5 — — 2 149 — Eliminations — (168 ) — — (508 ) — Consolidated $ 6,570 $ — $ 305 $ 350 $ 8,439 $ 785 Reconciling items (9 ) Capital expenditures per Statements of Consolidated Cash Flows $ 776 As of and for the year ended December 31, 2018: Natural Gas Distribution $ 2,931 $ 36 $ 277 $ 266 $ 6,956 $ 638 Energy Services 4,411 110 16 (47 ) 1,558 20 Other Operations 1 — — 3 66 — Eliminations — (146 ) — — (366 ) — Consolidated $ 7,343 $ — $ 293 $ 222 $ 8,214 $ 658 Reconciling items (25 ) Capital expenditures per Statements of Consolidated Cash Flows $ 633 Revenues from External Customers Net Intersegment Revenues Depreciation and Amortization Operating Income (Loss) Total Assets (1) Expenditures for Long-Lived Assets (in millions) As of and for the year ended December 31, 2017: Natural Gas Distribution $ 2,606 $ 33 $ 260 $ 348 $ 6,608 $ 523 Energy Services 3,997 52 19 126 1,521 11 Discontinued operations — — — — 2,472 (1) — Other Operations — — — (7 ) 70 — Eliminations — (85 ) — — (559 ) — Consolidated $ 6,603 $ — $ 279 $ 467 $ 10,112 $ 534 Reconciling items (21 ) Capital expenditures per Statements of Consolidated Cash Flows $ 513 (1) On September 4, 2018, CERC completed the Internal Spin. For further information regarding the Internal Spin, see Note 11 . Year Ended December 31, 2019 2018 2017 Revenues by Products and Services: CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Electric delivery $ 3,019 $ 2,990 $ — $ 3,232 $ 3,234 $ — $ 2,997 $ 2,998 $ — Retail electric sales 486 — — — — — — — — Wholesale electric sales 14 — — — — — — — — Retail gas sales 4,802 — 4,070 4,161 — 4,161 3,634 — 3,634 Wholesale gas sales 2,312 — 2,313 3,008 — 3,008 2,811 — 2,811 Gas transportation and processing 33 — 33 32 — 32 29 — 29 Infrastructure services 1,186 — — — — — — — — Energy products and services 449 — 154 156 — 142 143 — 129 Total $ 12,301 $ 2,990 $ 6,570 $ 10,589 $ 3,234 $ 7,343 $ 9,614 $ 2,998 $ 6,603

Supplemental Disclosure of Cash

Supplemental Disclosure of Cash Flow Information	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Supplemental Disclosure of Cash Flow Information [Text Block]	(20) Supplemental Disclosure of Cash Flow Information The tables below provide supplemental disclosure of cash flow information: 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Cash Payments/Receipts: Interest, net of capitalized interest $ 436 $ 229 $ 109 $ 363 $ 200 $ 105 $ 378 $ 205 $ 116 Income taxes (refunds), net 155 87 7 89 154 3 15 76 4 Non-cash transactions: Accounts payable related to capital expenditures 236 117 86 201 124 80 144 104 56 Capital distribution associated with the Internal Spin (1) — — 28 — — 1,473 — — — ROU assets obtained in exchange for lease liabilities (2) 44 1 29 — — — — — — (1) The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018. (2) Includes the transition impact of adoption of ASU 2016-02 Leases as of January 1, 2019. The Registrants elected not to recast comparative periods in the year of adoption as permitted by the standard. The table below provides a reconciliation of cash, cash equivalents and restricted cash reported in the Consolidated Balance Sheets to the amount reported in the Statements of Consolidated Cash Flows: December 31, 2019 December 31, 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Cash and cash equivalents (1) (2) $ 241 $ 216 $ 2 $ 4,231 $ 335 $ 14 Restricted cash included in Prepaid expenses and other current assets 30 19 — 46 34 11 Restricted cash included in Other — — — 1 1 — Total cash, cash equivalents and restricted cash shown in Statements of Consolidated Cash Flows $ 271 $ 235 $ 2 $ 4,278 $ 370 $ 25 (1) CenterPoint Energy’s Cash and cash equivalents as of December 31, 2018 included $3.9 billion of temporary investments resulting from the Merger financings. CenterPoint Energy recorded interest income of $22 million , $28 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on CenterPoint Energy’s Statements of Consolidated Income. See Notes 13 and 14 for further details related to the Merger financings. (2) Houston Electric’s Cash and cash equivalents as of December 31, 2019 and 2018 included $216 million and $335 million , respectively, of cash related to the Bond Companies. Houston Electric recorded interest income of $9 million , $4 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on Houston Electric’s Statement of Consolidated Income.

Related Party Transactions (Hou

Related Party Transactions (Houston Electric and CERC)	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions (Houston Electric and CERC) [Text Block]	Related Party Transactions (Houston Electric and CERC) Houston Electric and CERC participate in a money pool through which they can borrow or invest on a short-term basis. Funding needs are aggregated and external borrowing or investing is based on the net cash position. The net funding requirements of the money pool are expected to be met with borrowings under CenterPoint Energy’s revolving credit facility or the sale of CenterPoint Energy’s commercial paper. The table below summarizes money pool activity: December 31, 2019 December 31, 2018 Houston Electric CERC Houston Electric CERC (in millions) Money pool investments (borrowings) (1) $ 481 $ — $ (1 ) $ 114 Weighted average interest rate 1.98 % 1.98 % 2.42 % 2.42 % (1) Included in Accounts and notes receivable (payable)–affiliated companies in Houston Electric’s and CERC’s Consolidated Balance Sheets. Houston Electric and CERC affiliate-related net interest income (expense) were as follows: Year Ended December 31, 2019 2018 2017 Houston Electric CERC Houston Electric CERC Houston Electric CERC (in millions) Interest income (expense), net (1) $ 18 $ 4 $ 1 $ — $ 2 $ — (1) Interest income is included in Other, net and interest expense is included in Interest and other finance charges on Houston Electric’s and CERC’s respective Statements of Consolidated Income. CenterPoint Energy provides some corporate services to Houston Electric and CERC. The costs of services have been charged directly to Houston Electric and CERC using methods that management believes are reasonable. These methods include negotiated usage rates, dedicated asset assignment and proportionate corporate formulas based on operating expenses, assets, gross margin, employees and a composite of assets, gross margin and employees. Houston Electric provides certain services to CERC. These services are billed at actual cost, either directly or as an allocation and include fleet services, shop services, geographic services, surveying and right-of-way services, radio communications, data circuit management and field operations. Additionally, CERC provides certain services to Houston Electric. These services are billed at actual cost, either directly or as an allocation and include line locating and other miscellaneous services. These charges are not necessarily indicative of what would have been incurred had Houston Electric and CERC not been affiliates. Infrastructure Services provides pipeline construction and repair services to CERC’s NGD. Additionally, CERC, through its subsidiary CES, sells natural gas to Indiana Electric for use in electric generation activities. Amounts charged for these services are included primarily in Operation and maintenance expenses and amounts billed for natural gas sales are included in Non-utility revenues were as follows: Year Ended December 31, 2019 2018 2017 Houston Electric CERC Houston Electric CERC Houston Electric CERC (in millions) Corporate service charges $ 177 $ 141 $ 190 $ 147 $ 188 $ 128 Net affiliate service charges (billings) (8 ) 8 (17 ) 17 (9 ) 9 Pipeline construction and repair service charges (1) — 4 — — — — Natural gas sales (2) — 1 — — — — (1) Represents charges from Infrastructure Services to CERC’s NGD for the period February 1, 2019 through December 31, 2019. (2) Represents sales to Indiana Electric from CES for the period February 1, 2019 through December 31, 2019. The table below presents transactions among Houston Electric, CERC and their parent, Utility Holding. Year Ended December 31, 2019 2018 2017 Houston Electric CERC Houston Electric CERC Houston Electric CERC (in millions) Cash dividends paid to parent $ 376 $ 120 $ 209 $ 360 $ 180 $ 601 Cash contribution from parent 590 129 200 960 — 38 Capital distribution to parent associated with the Internal Spin (1) — 28 — 1,473 — — (1) The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.

Leases (Notes)

Leases (Notes)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases [Text Block]	Leases The Registrants adopted ASC 842, Leases, and all related amendments on January 1, 2019 using the modified retrospective transition method and elected not to recast comparative periods in the year of adoption as permitted by the standard. There was no adjustment to retained earnings as a result of transition. As a result, disclosures for periods prior to adoption will be presented in accordance with accounting standards in effect for those periods. The Registrants also elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed them to carry forward the historical lease classification. Additionally, the Registrants elected the practical expedient related to land easements, which allows the carry forward of the accounting treatment for land easements on existing agreements. The total ROU assets obtained in exchange for new operating lease liabilities upon adoption were $30 million , $1 million and $27 million for CenterPoint Energy, Houston Electric and CERC, respectively. The Merger was completed on February 1, 2019, and as such the amounts recorded upon adoption are exclusive of Vectren’s leases. An arrangement is determined to be a lease at inception based on whether the Registrant has the right to control the use of an identified asset. ROU assets represent the Registrants’ right to use the underlying asset for the lease term and lease liabilities represent the Registrants’ obligation to make lease payments arising from the lease. ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term, including payments at commencement that depend on an index or rate. Most leases in which the Registrants are the lessee do not have a readily determinable implicit rate, so an incremental borrowing rate, based on the information available at the lease commencement date, is utilized to determine the present value of lease payments. When a secured borrowing rate is not readily available, unsecured borrowing rates are adjusted for the effects of collateral to determine the incremental borrowing rate. Each Registrant uses the implicit rate for agreements in which it is a lessor. Lease expense and lease income are recognized on a straight-line basis over the lease term for operating leases. The Registrants have lease agreements with lease and non-lease components and have elected the practical expedient to combine lease and non-lease components for certain classes of leases, such as office buildings. For classes of leases in which lease and non-lease components are not combined, consideration is allocated between components based on the stand-alone prices. Sublease income is not significant to the Registrants. The Registrants’ lease agreements do not contain any material residual value guarantees, material restrictions or material covenants. There are no material lease transactions with related parties. Agreements in which the Registrants are lessors do not include provisions for the lessee to purchase the assets. Because risk is minimal, the Registrants do not take any significant actions to manage risk associated with the residual value of their leased assets. The Registrants’ lease agreements are primarily equipment and real property leases, including land and office facility leases. The Registrants’ lease terms may include options to extend or terminate a lease when it is reasonably certain that those options will be exercised. Operating lease payments exclude approximately $16 million of legally-binding undiscounted minimum lease payments for leases signed but not yet commenced. The Registrants have elected an accounting policy that exempts leases with terms of one year or less from the recognition requirements of ASC 842. The components of lease cost, included in Operation and maintenance expense on the Registrants’ respective Statements of Consolidated Income, are as follows: Year Ended December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions) Operating lease cost $ 25 $ — $ 5 Short-term lease cost 75 23 — Variable lease cost 1 — 1 Total lease cost $ 101 $ 23 $ 6 The components of lease income were as follows: Year Ended December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions) Operating lease income $ 4 $ 2 $ 1 Variable lease income 2 — — Total lease income $ 6 $ 2 $ 1 Supplemental balance sheet information related to leases was as follows: December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions, except lease term and discount rate) Assets: Operating ROU assets (1) $ 63 $ 1 $ 24 Total leased assets $ 63 $ 1 $ 24 Liabilities: Current operating lease liability (2) $ 21 $ — $ 4 Non-current operating lease liability (3) 42 1 20 Total leased liabilities $ 63 $ 1 $ 24 Weighted-average remaining lease term (in years) - operating leases 5.1 5.2 7.7 Weighted-average discount rate - operating leases 3.42 % 3.52 % 3.67 % (1) Reported within Other assets in the Registrants’ respective Consolidated Balance Sheets. (2) Reported within Current other liabilities in the Registrants’ respective Consolidated Balance Sheets. (3) Reported within Other liabilities in the Registrants’ respective Consolidated Balance Sheets. As of December 31, 2019 , maturities of operating lease liabilities were as follows: CenterPoint Energy Houston Electric CERC (in millions) 2020 $ 22 $ 1 $ 6 2021 16 — 4 2022 9 — 4 2023 7 — 3 2024 3 — 2 2025 and beyond 12 — 9 Total lease payments 69 1 28 Less: Interest 6 — 4 Present value of lease liabilities $ 63 $ 1 $ 24 The following table sets forth information concerning the Registrants’ obligations under non-cancelable long-term operating leases as of December 31, 2018: CenterPoint Energy Houston Electric CERC (in millions) 2019 $ 6 $ 1 $ 5 2020 6 — 5 2021 5 — 4 2022 4 — 4 2023 3 — 3 2024 and beyond 12 — 11 Total (1) $ 36 $ 1 $ 32 (1) The Merger was completed on February 1, 2019. As such, these amounts are exclusive of Vectren’s leases. As of December 31, 2019 , maturities of undiscounted operating lease payments to be received are as follows: CenterPoint Energy Houston Electric CERC (in millions) 2020 $ 3 $ 1 $ 1 2021 2 — — 2022 2 — — 2023 2 — — 2024 2 — — 2025 and beyond 10 — — Total lease payments to be received $ 21 $ 1 $ 1 Other information related to leases is as follows. See Note 20 for information on ROU assets obtained in exchange for operating lease liabilities: Year Ended December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions) Operating cash flows from operating leases included in the measurement of lease liabilities $ 25 $ 1 $ 6

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events (CenterPoint Energy) Proposed Divestiture of Infrastructure Services (CenterPoint Energy) On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment to PowerTeam Services. Subject to the terms and conditions of the Securities Purchase Agreement, PowerTeam Services has agreed to purchase all of the outstanding equity interests of VISCO for approximately $850 million , subject to customary adjustments set forth in the Securities Purchase Agreement, including adjustments based on VISCO’s net working capital at closing, indebtedness, cash and cash equivalents and transaction expenses. Per the Securities Purchase Agreement, VISCO will be converted from a wholly-owned corporation to a limited liability company that is disregarded for federal income tax purposes immediately prior to the closing of the transaction resulting in the sale of membership units at closing. The sale will be considered an asset sale for tax purposes requiring the net deferred tax liabilities of approximately $123 million as of December 31, 2019 to be recognized; therefore, any deferred tax assets and liabilities within the reporting unit are not included in the carrying amount of the assets and liabilities that will be transferred to PowerTeam Services. The completion of the sale is subject to customary closing conditions, including, among others (i) the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Act and (ii) customary conditions regarding the accuracy of the representations and warranties and compliance by the parties in all material respects with their respective obligations under the Securities Purchase Agreement. The Securities Purchase Agreement also includes customary termination provisions, including if the closing of the sale has not occurred on or before June 3, 2020. The sale is not subject to a financing condition and is expected to close in the second quarter of 2020, subject to satisfaction of the foregoing conditions, among other things. On February18, 2020, CenterPoint Energy received notice from the Federal Trade Commission granting early termination of the waiting period under the Hart-Scott-Rodino Act in connection with the proposed sale of Infrastructure Services. Proposed Divestiture of Energy Services (CenterPoint Energy and CERC) On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment, to Athena Energy Services. This transaction does not include CEIP and its assets. Subject to the terms and conditions of the Equity Purchase Agreement, Athena Energy Services has agreed to purchase all of the outstanding equity interests of CES for approximately $400 million , subject to customary adjustments set forth in the Equity Purchase Agreement, including adjustments based on CES’s net working capital at closing, indebtedness and transaction expenses. Per the Equity Purchase Agreement, CES will be converted from a wholly-owned corporation to a limited liability company that is disregarded for federal income tax purposes immediately prior to the closing of the transaction resulting in the sale of membership units at closing. The sale will be considered an asset sale for tax purposes requiring the net deferred tax liabilities of approximately $25 million as of December 31, 2019 to be recognized; therefore, any deferred tax assets and liabilities within the reporting unit are not included in the carrying amount of the assets and liabilities that will be transferred to the buyer. The completion of the sale is subject to customary closing conditions, including, among others (i) the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Act and (ii) the conversion of CES to a Delaware limited liability company, (iii) the distribution of the equity interests in CenterPoint Energy Intrastate Pipelines, LLC held by CES to CERC Corp. or its affiliates and (iv) customary conditions regarding the accuracy of the representations and warranties and compliance by the parties in all material respects with their respective obligations under the Equity Purchase Agreement. The Equity Purchase Agreement includes customary termination provisions, including if the closing of the transaction has not occurred on or before June 24, 2020.The sale is not subject to a financing condition and is expected to close in the second quarter of 2020, subject to satisfaction of the foregoing conditions, among other things. CenterPoint Energy Dividend Declarations (CenterPoint Energy) Equity Instrument Declaration Date Record Date Payment Date Per Share Common Stock February 3, 2020 February 20, 2020 March 12, 2020 $ 0.2900 Series A Preferred Stock February 3, 2020 February 14, 2020 March 2, 2020 30.6250 Series B Preferred Stock February 3, 2020 February 14, 2020 March 2, 2020 17.5000 Enable Distributions Declarations (CenterPoint Energy) Equity Instrument Declaration Date Record Date Payment Date Per Unit Distribution Expected Cash Distribution (in millions) Enable common units February 7, 2020 February 18, 2020 February 25, 2020 $ 0.3305 $ 77 Enable Series A Preferred Units February 7, 2020 February 7, 2020 February 14, 2020 0.6250 9

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Principles of Consolidation	Principles of Consolidation The accounts of the Registrants and their wholly-owned and majority-owned and controlled subsidiaries are included in the consolidated financial statements. All intercompany transactions and balances are eliminated in consolidation, except as described below. Businesses within the Infrastructure Services reportable segment provide underground pipeline construction and repair services for customers that include NGD utilities. In accordance with consolidation guidance in ASC 980—Regulated Operations, costs incurred by NGD utilities for these pipeline construction and repair services are not eliminated in consolidation when capitalized and included in rate base by the NGD utility. Fees incurred by CenterPoint Energy’s and CERC’s NGD for pipeline construction and repair services that were capitalized totaled $162 million and $20 million , respectively, for the 11 months ended December 31, 2019. On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. As of December 31, 2019 , CenterPoint Energy and Houston Electric had VIEs consisting of the Bond Companies, which are consolidated. The consolidated VIEs are wholly-owned, bankruptcy remote special purpose entities that were formed solely for the purpose of securitizing transition and system restoration related property. Creditors of CenterPoint Energy and Houston Electric have no recourse to any assets or revenues of the Bond Companies. The bonds issued by these VIEs are payable only from and secured by transition and system restoration property and the bondholders have no recourse to the general credit of CenterPoint Energy or Houston Electric.
Equity and Investments without a Readily Determinable Fair Value (CenterPoint Energy and CERC)	Equity and Investments without a Readily Determinable Fair Value (CenterPoint Energy) CenterPoint Energy generally uses the equity method of accounting for investments in entities in which it has an ownership interest between 20% and 50% and exercises significant influence. CenterPoint Energy also uses the equity method for investments in which it has ownership percentages greater than 50%, when it exercises significant influence, does not have control and is not considered the primary beneficiary, if applicable. Under the equity method, CenterPoint Energy adjusts its investments each period for contributions made, distributions received, respective shares of comprehensive income and amortization of basis differences, as appropriate. CenterPoint Energy evaluates its equity method investments for impairment when events or changes in circumstances indicate there is a loss in value of the investment that is other than a temporary decline. CenterPoint Energy considers distributions received from equity method investments which do not exceed cumulative equity in earnings subsequent to the date of investment to be a return on investment and classifies these distributions as operating activities in its Statements of Consolidated Cash Flows. CenterPoint Energy considers distributions received from equity method investments in excess of cumulative equity in earnings subsequent to the date of investment to be a return of investment and classifies these distributions as investing activities in its Statements of Consolidated Cash Flows. Investments without a readily determinable fair value will be measured at cost, less impairment, plus or minus observable prices changes of an identical or similar investment of the same issuer.
Revenues	Revenues The Registrants record revenue for electricity delivery and natural gas sales and services under the accrual method and these revenues are recognized upon delivery to customers. Electricity deliveries not billed by month-end are accrued based on actual AMS data, daily supply volumes and applicable rates. Natural gas sales not billed by month-end are accrued based upon estimated purchased gas volumes, estimated lost and unaccounted for gas and currently effective tariff rates. Revenue for some pipeline construction services are based on the percentage of completion method. For further discussion, see Note 5 .
MISO Transactions	MISO Transactions Indiana Electric is a member of the MISO. MISO-related purchase and sale transactions are recorded using settlement information provided by the MISO. These purchase and sale transactions are accounted for on at least a net hourly position, meaning net purchases within that interval are recorded on CenterPoint Energy’s Statements of Consolidated Income in Utility natural gas, fuel and purchased power, and net sales within that interval are recorded on CenterPoint Energy’s Statements of Consolidated Income in Utility revenues. On occasion, prior period transactions are resettled outside the routine process due to a change in the MISO’s tariff or a material interpretation thereof. Expenses associated with resettlements are recorded once the resettlement is probable and the resettlement amount can be estimated. Revenues associated with resettlements are recognized when the amount is determinable and collectability is reasonably assured.
Guarantees	Guarantees CenterPoint Energy recognizes guarantee obligations at fair value. CenterPoint Energy discloses parent company guarantees of a subsidiary’s obligation when that guarantee results in the exposure of a material obligation of the parent company even if the probability of fulfilling such obligation is considered remote. See Note 16(c) and (d).
Long-lived Assets, Goodwill and Intangibles	Long-lived Assets, Goodwill and Intangibles The Registrants record property, plant and equipment at historical cost and expense repair and maintenance costs as incurred. The Registrants periodically evaluate long-lived assets, including property, plant and equipment, and specifically identifiable intangibles subject to amortization, when events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. For rate regulated businesses, recoverability of long-lived assets is assessed by determining if a capital disallowance from a regulator is probable through monitoring the outcome of rate cases and other proceedings. For non-rate regulated businesses, recoverability is assessed based on an estimate of undiscounted cash flows attributable to the assets compared to the carrying value of the assets. As of December 31, 2019, CenterPoint Energy and CERC, as applicable, determined that the carrying value of long-lived and intangible assets associated with the Infrastructure Services and Energy Services reporting units were recoverable based on undiscounted cash flows, considering the likelihood of possible outcomes existing as of that date, including the assessment of the likelihood of a future sale of these assets. No long-lived asset or intangible asset impairments were recorded in 2019, 2018 or 2017. CenterPoint Energy and CERC perform goodwill impairment tests at least annually and evaluate goodwill when events or changes in circumstances indicate that its carrying value may not be recoverable. Subsequent to the Registrant’s adoption of ASU 2017-04 Simplifying the Test for Goodwill Impairment on January 1, 2018, CenterPoint Energy and CERC recognize a goodwill impairment by the amount a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill within that reporting unit. CenterPoint Energy includes deferred tax assets and liabilities within its reporting unit’s carrying value for the purposes of annual and interim impairment tests, regardless of whether the estimated fair value reflects the disposition of such assets and liabilities. For further information about the goodwill impairment tests during 2019, see Note 6.
Assets Held for Sale and Discontinued Operations	Assets Held for Sale and Discontinued Operations Generally, a long-lived asset to be sold is classified as held for sale in the period in which management, with approval from the Board of Directors, as applicable, commits to a plan to sell and a sale is expected to be completed within one year. The Registrants record assets and liabilities held for sale at the lower of their carrying value or their estimated fair value less cost to sell. If the disposal group reflects a component of a reporting unit and meets the definition of a business, the goodwill within that reporting unit is allocated to the disposal group based on the relative fair value of the components representing a business that will be retained and disposed. Goodwill is not allocated to a portion of a reporting unit that does not meet the definition of a business. A disposal group that meets the held for sale criteria and also represents a strategic shift to the Registrant, is also reflected as discontinued operations on the Statements of Consolidated Income, and prior periods are recast to reflect the earnings or losses from such businesses as income from discontinued operations, net of tax.
Regulatory Assets and Liabilities	Regulatory Assets and Liabilities The Registrants apply the guidance for accounting for regulated operations to the Houston Electric T&D reportable segment, Indiana Electric Integrated segment and the Natural Gas Distribution reportable segment. The Registrants’ rate-regulated subsidiaries may collect revenues subject to refund pending final determination in rate proceedings. In connection with such revenues, estimated rate refund liabilities are recorded which reflect management’s current judgment of the ultimate outcomes of the proceedings. The Registrants’ rate-regulated businesses recognize removal costs as a component of depreciation expense in accordance with regulatory treatment. In addition, a portion of the amount of removal costs collected from customers that relate to AROs has been reflected as an asset retirement liability in accordance with accounting guidance for AROs. For further detail on the Registrants’ regulatory assets and liabilities, see Note 7 .
Depreciation and Amortization Expense	Depreciation and Amortization Expense The Registrants compute depreciation and amortization using the straight-line method based on economic lives or regulatory-mandated recovery periods. Amortization expense includes amortization of certain regulatory assets and other intangibles.
Capitalization of Interest and AFUDC	Capitalization of Interest and AFUDC The Registrants capitalize interest and AFUDC as a component of projects under construction and amortize it over the assets’ estimated useful lives once the assets are placed in service. AFUDC represents the composite interest cost of borrowed funds and a reasonable return on the equity funds used for construction for subsidiaries that apply the guidance for accounting for regulated operations. Although AFUDC increases both utility plant and earnings, it is realized in cash when the assets are included in rates. Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Interest and AFUDC debt (1) $ 36 $ 8 $ 3 $ 8 $ 6 $ 2 $ 9 $ 6 $ 2 AFUDC equity (2) 22 15 3 12 10 2 11 10 1 (1) Included in Interest and other finance charges on the Registrants’ respective Statements of Consolidated Income. (2) Included in Other Income (Expense) on the Registrants’ respective Statements of Consolidated Income.
Income Taxes	Income Taxes Houston Electric and CERC are included in CenterPoint Energy’s U.S. federal consolidated income tax return. Houston Electric and CERC report their income tax provision on a separate entity basis pursuant to a tax sharing agreement with CenterPoint Energy. Current federal and certain state income taxes are payable to or receivable from CenterPoint Energy. The Registrants use the asset and liability method of accounting for deferred income taxes. Deferred income tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. A valuation allowance is established against deferred tax assets for which management believes realization is not considered to be more likely than not. The Registrants recognize interest and penalties as a component of income tax expense (benefit), as applicable, in their respective Statements of Consolidated Income. CenterPoint Energy reports the income tax provision associated with its interest in Enable in income tax expense (benefit) in its Statements of Consolidated Income. On December 22, 2017, President Trump signed into law comprehensive tax reform legislation informally called the Tax Cuts and Jobs Acts, or TCJA, which resulted in significant changes to federal tax laws effective January 1, 2018. See Note 15 for further discussion of the impacts of tax reform implementation. To the extent certain EDIT of the Registrants’ rate-regulated subsidiaries may be recoverable or payable through future rates, regulatory assets and liabilities have been recorded, respectively. The Registrants use the portfolio approach to recognize income tax effects on other comprehensive income from accumulated other comprehensive income. Investment tax credits are deferred and amortized to income over the approximate lives of the related property.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount and do not bear interest. Management reviews the outstanding accounts receivable, as well as the bad debt write-offs experienced in the past, and establishes an allowance for doubtful accounts. Account balances are charged off against the allowance when management determines it is probable the receivable will not be recovered. The table below summarizes the Registrants’ provision for doubtful accounts for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Provision for doubtful accounts $ 16 $ — $ 12 $ 16 $ — $ 16 $ 14 $ 1 $ 13
Inventory	Inventory The Registrants’ inventory consists principally of materials and supplies, and for CERC, natural gas, and for CenterPoint Energy, coal inventory. Materials and supplies are valued at the lower of average cost or market. Materials and supplies are recorded to inventory when purchased and subsequently charged to expense or capitalized to plant when installed. Natural gas inventories of CERC’s Energy Services reportable segment at locations qualifying for and utilizing the fair value hedge accounting election are valued at fair value; inventories at locations not qualifying for or not utilizing the fair value hedge accounting election are valued at the lower of average cost or market. During 2019 , 2018 and 2017 , CERC recorded write-downs of natural gas inventory to the lower of average cost or market which are disclosed on the respective Statements of Consolidated Cash Flows.
Derivative Instruments	Derivative Instruments The Registrants are exposed to various market risks. These risks arise from transactions entered into in the normal course of business. The Registrants utilize derivative instruments such as physical forward contracts, swaps and options to mitigate the impact of changes in commodity prices, weather and interest rates on operating results and cash flows. Such derivatives are recognized in the Registrants’ Consolidated Balance Sheets at their fair value unless the Registrant elects the normal purchase and sales exemption for qualified physical transactions. A derivative may be designated as a normal purchase or normal sale if the intent is to physically receive or deliver the product for use or sale in the normal course of business. CenterPoint Energy and CERC have elected to record changes in the fair value of amounts excluded from the assessment of effectiveness immediately in their Statements of Consolidated Income. CenterPoint Energy has a Risk Oversight Committee composed of corporate and reportable segment officers that oversees commodity price, weather and credit risk activities, including the Registrants’ marketing, risk management services and hedging activities. The committee’s duties are to establish the Registrants’ commodity risk policies, allocate board-approved commercial risk limits, approve the use of new products and commodities, monitor positions and ensure compliance with the Registrants’ risk management policies and procedures and limits established by CenterPoint Energy’s Board of Directors. The Registrants’ policies prohibit the use of leveraged financial instruments. A leveraged financial instrument, for this purpose, is a transaction involving a derivative whose financial impact will be based on an amount other than the notional amount or volume of the instrument.
Investments in Equity Securities (CenterPoint Energy and CERC)	Investments in Equity Securities (CenterPoint Energy and CERC) CenterPoint Energy and CERC report equity securities at estimated fair value in their respective Consolidated Balance Sheets, and any unrealized holding gains and losses are recorded as Other Income (Expense) in their respective Statements of Consolidated Income.
Environmental Costs	Environmental Costs The Registrants expense or capitalize environmental expenditures, as appropriate, depending on their future economic benefit. The Registrants expense amounts that relate to an existing condition caused by past operations that do not have future economic benefit. The Registrants record undiscounted liabilities related to these future costs when environmental assessments and/or remediation activities are probable and the costs can be reasonably estimated.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash For purposes of reporting cash flows, the Registrants consider cash equivalents to be short-term, highly-liquid investments with maturities of three months or less from the date of purchase. Cash and cash equivalents held by the Bond Companies (VIEs) solely to support servicing the Securitization Bonds as of December 31, 2019 and 2018 are reflected on CenterPoint Energy’s and Houston Electric’s Consolidated Balance Sheets. In connection with the issuance of Securitization Bonds, CenterPoint Energy and Houston Electric were required to establish restricted cash accounts to collateralize the bonds that were issued in these financing transactions. These restricted cash accounts are not available for withdrawal until the maturity of the bonds and are not included in cash and cash equivalents. For more information on restricted cash see Note 20
Preferred Stock Dividends	Preferred Stock and Dividends Preferred stock is evaluated to determine balance sheet classification, and all conversion and redemption features are evaluated for bifurcation treatment. Proceeds received net of issuance costs are recognized on the settlement date. Cash dividends become a liability once declared. Income available to common stockholders is computed by deducting from net income the dividends accumulated and earned during the period on cumulative preferred stock.
Purchase Accounting	Purchase Accounting The Registrants evaluate acquisitions to determine when a set of acquired activities and assets represent a business. When control of a business is obtained, the Registrants apply the acquisition method of accounting and record the assets acquired, liabilities assumed and any non-controlling interest obtained based on fair value at the acquisition date. The excess of the fair value of purchase consideration over the fair value of the net assets acquired is recorded as goodwill. The results of operations of the acquired business are included in the Registrants’ respective Statements of Consolidated Income beginning on the date of the acquisition.
New Accounting Pronouncements	New Accounting Pronouncements The following table provides an overview of certain recently adopted or issued accounting pronouncements applicable to all the Registrants, unless otherwise noted. Recently Adopted Accounting Standards ASU Number and Name Description Date of Adoption Financial Statement Impact upon Adoption ASU 2016-02- Leases (Topic 842) and related amendments ASU 2016-02 provides a comprehensive new lease model that requires lessees to recognize assets and liabilities for most leases and would change certain aspects of lessor accounting. Transition method: modified retrospective January 1, 2019 The Registrants adopted the standard and recognized a right-of-use asset and lease liability on their statement of financial position with no material impact on their results of operations and cash flows. See Note 22 for more information. Issued, Not Yet Effective Accounting Standards ASU Number and Name Description Effective Date Financial Statement Impact upon Adoption ASU 2016-13- Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments This standard, including standards amending this standard, requires a new model called CECL to estimate credit losses for (1) financial assets subject to credit losses and measured at amortized cost and (2) certain off-balance sheet credit exposures. Upon initial recognition of the exposure, the CECL model requires an entity to estimate the credit losses expected over the life of an exposure based on historical information, current information and reasonable and supportable forecasts, including estimates of prepayments. Transition method : modified retrospective January 1, 2020 Early adoption is permitted The adoption of this standard will result in an immaterial adjustment to the carrying value of the Registrants’ accounts receivable, net. The adoption of this standard will not have a material impact on the Registrants’ financial position, results of operations or cash flows. ASU 2018-13- Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement This standard eliminates, modifies and adds certain disclosure requirements for fair value measurements. Transition method : prospective for additions and one modification and retrospective for all other amendments Adoption of eliminations and modifications as of September 30, 2018; Additions will be adopted January 1, 2020 The adoption of this standard did not impact the Registrants’ financial position, results of operations or cash flows. Note 10 reflects the disclosures modified upon adoption. ASU 2018-15-Intangibles-Goodwill and Other- Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract This standard aligns accounting for implementation costs incurred in a cloud computing arrangement that is accounted for as a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The update also prescribes the balance sheet, income statement and cash flow classification of the capitalized implementation costs and related amortization expense and requires additional quantitative and qualitative disclosures. Transition method : retrospective or prospective January 1, 2020 Early adoption is permitted The adoption of this standard will require the Registrants to capitalize certain costs to implement cloud computing arrangements that are accounted for as service contracts within Prepaid expenses and other current assets on the Registrants’ consolidated balance sheets and record the amortization of such assets within Operation and maintenance expenses on the Registrants’ statements of consolidated income. The adoption of this standard will not have a material impact on the Registrants’ financial position, results of operations, cash flows or disclosures. Management believes that other recently adopted standards and recently issued standards that are not yet effective will not have a material impact on the Registrants’ financial position, results of operations or cash flows upon adoption.

Leases (Policies)

Leases (Policies)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lessee, Leases [Policy Text Block]	The Registrants adopted ASC 842, Leases, and all related amendments on January 1, 2019 using the modified retrospective transition method and elected not to recast comparative periods in the year of adoption as permitted by the standard. There was no adjustment to retained earnings as a result of transition. As a result, disclosures for periods prior to adoption will be presented in accordance with accounting standards in effect for those periods. The Registrants also elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed them to carry forward the historical lease classification. Additionally, the Registrants elected the practical expedient related to land easements, which allows the carry forward of the accounting treatment for land easements on existing agreements. The total ROU assets obtained in exchange for new operating lease liabilities upon adoption were $30 million , $1 million and $27 million for CenterPoint Energy, Houston Electric and CERC, respectively. The Merger was completed on February 1, 2019, and as such the amounts recorded upon adoption are exclusive of Vectren’s leases. An arrangement is determined to be a lease at inception based on whether the Registrant has the right to control the use of an identified asset. ROU assets represent the Registrants’ right to use the underlying asset for the lease term and lease liabilities represent the Registrants’ obligation to make lease payments arising from the lease. ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term, including payments at commencement that depend on an index or rate. Most leases in which the Registrants are the lessee do not have a readily determinable implicit rate, so an incremental borrowing rate, based on the information available at the lease commencement date, is utilized to determine the present value of lease payments. When a secured borrowing rate is not readily available, unsecured borrowing rates are adjusted for the effects of collateral to determine the incremental borrowing rate. Each Registrant uses the implicit rate for agreements in which it is a lessor. Lease expense and lease income are recognized on a straight-line basis over the lease term for operating leases. The Registrants have lease agreements with lease and non-lease components and have elected the practical expedient to combine lease and non-lease components for certain classes of leases, such as office buildings. For classes of leases in which lease and non-lease components are not combined, consideration is allocated between components based on the stand-alone prices. Sublease income is not significant to the Registrants. The Registrants’ lease agreements do not contain any material residual value guarantees, material restrictions or material covenants. There are no material lease transactions with related parties. Agreements in which the Registrants are lessors do not include provisions for the lessee to purchase the assets. Because risk is minimal, the Registrants do not take any significant actions to manage risk associated with the residual value of their leased assets. The Registrants’ lease agreements are primarily equipment and real property leases, including land and office facility leases. The Registrants’ lease terms may include options to extend or terminate a lease when it is reasonably certain that those options will be exercised. Operating lease payments exclude approximately $16 million of legally-binding undiscounted minimum lease payments for leases signed but not yet commenced. The Registrants have elected an accounting policy that exempts leases with terms of one year or less from the recognition requirements of ASC 842.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Public Utilities General Disclosures [Table Text Block]	The Registrants capitalize interest and AFUDC as a component of projects under construction and amortize it over the assets’ estimated useful lives once the assets are placed in service. AFUDC represents the composite interest cost of borrowed funds and a reasonable return on the equity funds used for construction for subsidiaries that apply the guidance for accounting for regulated operations. Although AFUDC increases both utility plant and earnings, it is realized in cash when the assets are included in rates. Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Interest and AFUDC debt (1) $ 36 $ 8 $ 3 $ 8 $ 6 $ 2 $ 9 $ 6 $ 2 AFUDC equity (2) 22 15 3 12 10 2 11 10 1 (1) Included in Interest and other finance charges on the Registrants’ respective Statements of Consolidated Income. (2) Included in Other Income (Expense) on the Registrants’ respective Statements of Consolidated Income.
Provision for doubtful accounts [Table Text Block]	The table below summarizes the Registrants’ provision for doubtful accounts for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Provision for doubtful accounts $ 16 $ — $ 12 $ 16 $ — $ 16 $ 14 $ 1 $ 13
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]	The following table provides an overview of certain recently adopted or issued accounting pronouncements applicable to all the Registrants, unless otherwise noted. Recently Adopted Accounting Standards ASU Number and Name Description Date of Adoption Financial Statement Impact upon Adoption ASU 2016-02- Leases (Topic 842) and related amendments ASU 2016-02 provides a comprehensive new lease model that requires lessees to recognize assets and liabilities for most leases and would change certain aspects of lessor accounting. Transition method: modified retrospective January 1, 2019 The Registrants adopted the standard and recognized a right-of-use asset and lease liability on their statement of financial position with no material impact on their results of operations and cash flows. See Note 22 for more information. Issued, Not Yet Effective Accounting Standards ASU Number and Name Description Effective Date Financial Statement Impact upon Adoption ASU 2016-13- Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments This standard, including standards amending this standard, requires a new model called CECL to estimate credit losses for (1) financial assets subject to credit losses and measured at amortized cost and (2) certain off-balance sheet credit exposures. Upon initial recognition of the exposure, the CECL model requires an entity to estimate the credit losses expected over the life of an exposure based on historical information, current information and reasonable and supportable forecasts, including estimates of prepayments. Transition method : modified retrospective January 1, 2020 Early adoption is permitted The adoption of this standard will result in an immaterial adjustment to the carrying value of the Registrants’ accounts receivable, net. The adoption of this standard will not have a material impact on the Registrants’ financial position, results of operations or cash flows. ASU 2018-13- Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement This standard eliminates, modifies and adds certain disclosure requirements for fair value measurements. Transition method : prospective for additions and one modification and retrospective for all other amendments Adoption of eliminations and modifications as of September 30, 2018; Additions will be adopted January 1, 2020 The adoption of this standard did not impact the Registrants’ financial position, results of operations or cash flows. Note 10 reflects the disclosures modified upon adoption. ASU 2018-15-Intangibles-Goodwill and Other- Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract This standard aligns accounting for implementation costs incurred in a cloud computing arrangement that is accounted for as a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The update also prescribes the balance sheet, income statement and cash flow classification of the capitalized implementation costs and related amortization expense and requires additional quantitative and qualitative disclosures. Transition method : retrospective or prospective January 1, 2020 Early adoption is permitted The adoption of this standard will require the Registrants to capitalize certain costs to implement cloud computing arrangements that are accounted for as service contracts within Prepaid expenses and other current assets on the Registrants’ consolidated balance sheets and record the amortization of such assets within Operation and maintenance expenses on the Registrants’ statements of consolidated income. The adoption of this standard will not have a material impact on the Registrants’ financial position, results of operations, cash flows or disclosures.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment [Table Text Block]	Property, plant and equipment includes the following: December 31, 2019 December 31, 2018 Weighted Average Useful Lives Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net (in years) (in millions) CenterPoint Energy Electric Transmission & Distribution 37 $ 14,360 $ 4,634 $ 9,726 $ 12,148 $ 3,746 $ 8,402 Electric Generation (1) 27 1,780 698 1,082 — — — Natural Gas Distribution 29 12,695 3,731 8,964 7,257 2,128 5,129 Energy Services (2) 27 136 53 83 121 43 78 Infrastructure Services (3) 10 317 22 295 — — — Other property 19 1,397 602 795 741 306 435 Total $ 30,685 $ 9,740 $ 20,945 $ 20,267 $ 6,223 $ 14,044 Houston Electric Electric Transmission 46 $ 3,358 $ 674 $ 2,684 $ 3,077 $ 650 $ 2,427 Electric Distribution 35 7,876 2,586 5,290 7,524 2,553 4,971 Other transmission & distribution property 19 1,595 537 1,058 1,547 543 1,004 Total $ 12,829 $ 3,797 $ 9,032 $ 12,148 $ 3,746 $ 8,402 December 31, 2019 December 31, 2018 Weighted Average Useful Lives Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net Property, Plant and Equipment, Gross Accumulated Depreciation & Amortization Property, Plant and Equipment, Net (in years) (in millions) CERC Natural Gas Distribution 29 $ 7,933 $ 2,208 $ 5,725 $ 7,257 $ 2,128 $ 5,129 Energy Services (2) 27 136 53 83 121 43 78 Other property 16 55 27 28 53 34 19 Total $ 8,124 $ 2,288 $ 5,836 $ 7,431 $ 2,205 $ 5,226 (1) SIGECO and AGC own a 300 MW unit at the Warrick Power Plant (Warrick Unit 4) as tenants in common. SIGECO’s share of the cost of this unit as of December 31, 2019, is $194 million with accumulated depreciation totaling $137 million . AGC and SIGECO share equally in the cost of operation and output of the unit. SIGECO’s share of operating costs is included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income. (2) On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23. (3) On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23.
Depreciation and Amortization [Table Text Block]	The following table presents depreciation and amortization expense for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Depreciation $ 920 $ 339 $ 281 $ 626 $ 342 $ 264 $ 619 $ 354 $ 243 Amortization of securitized regulatory assets 271 271 — 531 531 — 329 329 — Other amortization 96 38 24 86 44 29 88 41 36 Total $ 1,287 $ 648 $ 305 $ 1,243 $ 917 $ 293 $ 1,036 $ 724 $ 279
Asset Retirement Obligation [Table Text Block]	A reconciliation of the changes in the ARO liability recorded in Other non-current liabilities on each of the Registrants’ respective Consolidated Balance Sheets is as follows: December 31, 2019 December 31, 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Beginning balance $ 258 $ 34 $ 221 $ 281 $ 35 $ 243 Addition from Merger with Vectren 116 — — — — — Accretion expense (1) 16 1 10 10 1 9 Revisions in estimates (2) 149 7 94 (33 ) (2 ) (31 ) Ending balance $ 539 $ 42 $ 325 $ 258 $ 34 $ 221 (1) Reflected in Regulatory assets on each of the Registrants’ respective Consolidated Balance Sheets. (2)

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The Merger is being accounted for in accordance with ASC 805, Business Combinations, with CenterPoint Energy as the accounting acquirer of Vectren. Identifiable assets acquired and liabilities assumed have been recorded at their estimated fair values on the Merger Date. Vectren’s regulated operations, comprised of electric generation and electric and natural gas energy delivery services, are subject to the rate-setting authority of the FERC, the IURC and the PUCO, and are accounted for pursuant to U.S. generally accepted accounting principles for regulated operations. The rate-setting and cost-recovery provisions currently in place for Vectren’s regulated operations provide revenues derived from costs including a return on investment of assets and liabilities included in rate base. Thus, the fair value of Vectren’s tangible and intangible assets and liabilities subject to these rate-setting provisions approximate their carrying values on the Merger Date. The fair value of regulatory assets not earning a return have been determined using the income approach and are considered Level 3 fair value measurements due to the use of significant judgmental and unobservable inputs. The fair value of Vectren’s assets acquired and liabilities assumed that are not subject to the rate-setting provisions, including identifiable intangibles, have been determined using the income approach and the market approach. The valuation of Vectren’s long-term debt is primarily considered a Level 2 fair value measurement. All other valuations are considered Level 3 fair value measurements due to the use of significant judgmental and unobservable inputs, including projected timing and amount of future cash flows and discount rates reflecting risk inherent in the future market prices. The following table presents the purchase price allocation as of December 31, 2019 (in millions): Cash and cash equivalents $ 16 Other current assets 577 Property, plant and equipment, net 5,147 Identifiable intangibles 297 Regulatory assets 338 Other assets 141 Total assets acquired 6,516 Current liabilities 648 Regulatory liabilities 938 Other liabilities 886 Long-term debt 2,401 Total liabilities assumed 4,873 Net assets acquired 1,643 Goodwill 4,339 Total purchase price consideration $ 5,982
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	The fair value of the identifiable intangible assets and related useful lives as included in the purchase price allocation as of December 31, 2019 include: Weighted Average Useful Lives Estimated Fair Value (in years) (in millions) Operation and maintenance agreements 24 $ 12 Customer relationships 18 200 Construction backlog 1 27 Trade names 10 58 Total $ 297
Business Combination, Separately Recognized Transactions [Table Text Block]	The results of operations for Vectren included in CenterPoint Energy’s Consolidated Financial Statements from the Merger Date for the year ended December 31, 2019 are as follows: (in millions) Operating revenues $ 2,729 Net income 190
Business Acquisition, Pro Forma Information [Table Text Block]	The following unaudited pro forma financial information reflects the consolidated results of operations of CenterPoint Energy, assuming the Merger had taken place on January 1, 2018. The unaudited pro forma financial information has been presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved had the Merger taken place on the dates indicated or of the future consolidated results of operations of the combined company. Year Ended December 31, 2019 2018 (in millions) Operating revenues $ 12,547 $ 13,282 Net income 812 (1) 458 (2) (1) Pro forma net income was adjusted to exclude $37 million of Vectren Merger-related transaction costs incurred in 2019. (2) Pro forma net income was adjusted to include $37 million of Vectren Merger-related transaction costs incurred in 2019 .

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table Text Block]	The following tables disaggregate revenues by reportable segment and major source: CenterPoint Energy Year Ended December 31, 2019 Houston Electric T&D (1) Indiana Electric Integrated (1) (4) Natural Gas Distribution (1) (4) Energy Services (2) Infrastructure Services (2) (4) Corporate and Other (2) (4) Total (in millions) Revenue from contracts $ 2,984 $ 523 $ 3,680 $ 479 $ 1,190 $ 295 $ 9,151 Derivatives income 6 — 2 3,303 — — 3,311 Other (3) 6 — 1 — — 5 12 Eliminations — — (40 ) (129 ) (4 ) — (173 ) Total revenues $ 2,996 $ 523 $ 3,643 $ 3,653 $ 1,186 $ 300 $ 12,301 Year Ended December 31, 2018 Houston Electric T&D (1) Indiana Electric Integrated (1) Natural Gas Distribution (1) Energy Services (2) Infrastructure Services (2) Corporate and Other (2) Total (in millions) Revenue from contracts $ 3,235 $ — $ 3,011 $ 493 $ — $ 6 $ 6,745 Derivatives income (2 ) — (2 ) 4,028 — — 4,024 Other (3) (1 ) — (42 ) — — 9 (34 ) Eliminations — — (36 ) (110 ) — — (146 ) Total revenues $ 3,232 $ — $ 2,931 $ 4,411 $ — $ 15 $ 10,589 Year Ended December 31, 2017 Houston Electric T&D (1) Indiana Electric Integrated (1) Natural Gas Distribution (1) Energy Services (2) Infrastructure Services (2) Corporate and Other (2) Total (in millions) Revenue from contracts $ 3,001 $ — $ 2,638 $ 480 $ — $ 5 $ 6,124 Derivatives income (1 ) — — 3,569 — — 3,568 Other (3) (3 ) — 1 — — 9 7 Eliminations — — (33 ) (52 ) — — (85 ) Total revenues $ 2,997 $ — $ 2,606 $ 3,997 $ — $ 14 $ 9,614 (1) Reflected in Utility revenues in the Statements of Consolidated Income. (2) Reflected in Non-utility revenues in the Statements of Consolidated Income. (3) Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period. (4) Reflects revenues from Vectren subsidiaries for the period from February 1, 2019 to December 31, 2019. Houston Electric Year Ended December 31, 2019 2018 2017 (in millions) Revenue from contracts $ 2,984 $ 3,235 $ 3,001 Other (1) 6 (1 ) (3 ) Total revenues $ 2,990 $ 3,234 $ 2,998 (1) Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period. CERC Year Ended December 31, 2019 Natural Gas Distribution (1) Energy Services (2) Corporate and Other (2) Total (in millions) Revenue from contracts $ 2,945 $ 480 $ 5 $ 3,430 Derivatives income 2 3,302 — 3,304 Other (3) 4 — — 4 Eliminations (40 ) (128 ) — (168 ) Total revenues $ 2,911 $ 3,654 $ 5 $ 6,570 Year Ended December 31, 2018 Natural Gas Distribution (1) Energy Services (2) Corporate Total (in millions) Revenue from contracts $ 3,011 $ 493 $ 1 $ 3,505 Derivatives income (2 ) 4,028 — 4,026 Other (3) (42 ) — — (42 ) Eliminations (36 ) (110 ) — (146 ) Total revenues $ 2,931 $ 4,411 $ 1 $ 7,343 Year Ended December 31, 2017 Natural Gas Distribution (1) Energy Services (2) Corporate Total (in millions) Revenue from contracts $ 2,638 $ 480 $ — $ 3,118 Derivatives income — 3,569 — 3,569 Other (3) 1 — — 1 Eliminations (33 ) (52 ) — (85 ) Total revenues $ 2,606 $ 3,997 $ — $ 6,603 (1) Reflected in Utility revenues in the Statements of Consolidated Income. (2) Reflected in Non-utility revenues in the Statements of Consolidated Income. (3) Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period.
Contract with Customer, Asset and Liability [Table Text Block]	The opening and closing balances of accounts receivable, other accrued unbilled revenue, contract assets and contract liabilities from contracts with customers for the year ended December 31, 2019 are as follows: CenterPoint Energy Accounts Receivable Other Accrued Unbilled Revenues Contract Assets Contract Liabilities (in millions) Opening balance as of December 31, 2018 (1) $ 516 $ 373 $ — $ 3 Closing balance as of December 31, 2019 800 579 61 34 Increase $ 284 $ 206 $ 61 $ 31 (1) Opening balances related to Vectren are as of February 1, 2019, and are thus excluded from the opening balance as of December 31, 2018. The amount of revenue recognized in the year ended December 31, 2019 that was included in the opening contract liability was $47 million . The difference between the opening and closing balances of the contract liabilities primarily results from the timing difference between CenterPoint Energy’s performance and the customer’s payment, plus the addition of obligations acquired in the Merger. Houston Electric Accounts Receivable Other Accrued Unbilled Revenues Contract Liabilities (in millions) Opening balance as of December 31, 2018 $ 234 $ 110 $ 3 Closing balance as of December 31, 2019 210 117 3 Increase (decrease) $ (24 ) $ 7 $ — The amount of revenue recognized in the year ended December 31, 2019 that was included in the opening contract liability was $3 million . The difference between the opening and closing balances of the contract liabilities primarily results from the timing difference between Houston Electric’s performance and the customer’s payment. CERC Accounts Receivable Other Accrued Unbilled Revenues (in millions) Opening balance as of December 31, 2018 $ 282 $ 263 Closing balance as of December 31, 2019 282 250 Increase (decrease) $ — $ (13 ) CERC does not have any opening or closing contract asset or contract liability balances.
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	Remaining Performance Obligations (CenterPoint Energy). The table below discloses (1) the aggregate amount of the transaction price allocated to performance obligations that are unsatisfied (or partially unsatisfied) as of the end of the reporting period for contracts and (2) when CenterPoint Energy expects to recognize this revenue. Such contracts include fixed price contracts and energy performance and sustainable infrastructure services contracts of ESG, which are included in Corporate and Other. Rolling 12 Months Thereafter Total (in millions) Revenue expected to be recognized on contracts in place as of December 31, 2019: Infrastructure Services $ 254 $ — $ 254 Corporate and Other 84 752 836 $ 338 $ 752 $ 1,090

Goodwill and Other Intangible_2

Goodwill and Other Intangibles (CenterPoint Energy and CERC) (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill by Reportable Segments [Table Text Block]	CenterPoint Energy’s goodwill by reportable segment as of December 31, 2018 and changes in the carrying amount of goodwill as of December 31, 2019 are as follows: December 31, 2018 Additions (1) Impairment December 31, (in millions) Indiana Electric Integrated $ — $ 1,121 $ — $ 1,121 Natural Gas Distribution 746 2,566 — 3,312 Energy Services (2) 110 — 48 62 Infrastructure Services — 220 — 220 Corporate and Other 11 438 — 449 Total $ 867 $ 4,345 $ 48 $ 5,164 (1) This represents the allocation of goodwill to reportable segments from the Merger, changes from preliminary amounts previously reported and includes the final determination of fair value for each reportable segment. See Note 4 . (2) Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012. As of December 31, 2019, CenterPoint Energy and CERC identified a triggering event to perform an interim goodwill impairment test and recognized a goodwill impairment on their Energy Services reporting unit which is included in Goodwill impairment on CenterPoint Energy’s and CERC’s Consolidated Statements of Income. CERC’s goodwill by reportable segment as of December 31, 2019 and December 31, 2018 is as follows: December 31, 2018 Impairment December 31, 2019 (in millions) Natural Gas Distribution $ 746 $ — $ 746 Energy Services (1) 110 48 62 Corporate and Other 11 — 11 Total $ 867 $ 48 $ 819 (1) Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012.
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The tables below present information on CERC’s other intangible assets recorded in Other non-current assets on CERC’s Consolidated Balance Sheets and the related amortization expense included in Depreciation and amortization on CERC’s Statements of Consolidated Income. December 31, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Balance Gross Carrying Amount Accumulated Amortization Net Balance (in millions) Customer relationships $ 86 $ (32 ) $ 54 $ 86 $ (27 ) $ 59 Covenants not to compete 4 (4 ) — 4 (3 ) 1 Other 16 (14 ) 2 16 (11 ) 5 Total $ 106 $ (50 ) $ 56 $ 106 $ (41 ) $ 65 The tables below present information on CenterPoint Energy’s other intangible assets recorded in Intangible assets, net on the Consolidated Balance Sheets and the related amortization expense included in Depreciation and amortization on CenterPoint Energy’s Statements of Consolidated Income, unless otherwise indicated. December 31, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Balance Gross Carrying Amount Accumulated Amortization Net Balance (in millions) Customer relationships (1) $ 286 $ (43 ) $ 243 $ 86 $ (27 ) $ 59 Covenants not to compete 4 (4 ) — 4 (3 ) 1 Trade names (1) 58 (5 ) 53 — — — Construction backlog (1) (2) 27 (23 ) 4 — — — Operation and maintenance agreements (1) (2) 12 (1 ) 11 — — — Other (1) 24 (14 ) 10 16 (11 ) 5 Total $ 411 $ (90 ) $ 321 $ 106 $ (41 ) $ 65 (1) The fair value of intangible assets acquired through acquisitions has been finalized. See Note 4 . (2) Amortization expense related to the operation and maintenance agreements and construction backlog is included in Non-utility cost of revenues, including natural gas on CenterPoint Energy’s Statements of Consolidated Income.
Finite-lived Intangible Assets Amortization Expense [Table Text Block]	Year Ended December 31, 2019 2018 2017 (in millions) Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2) $ 25 $ 10 $ 13 Amortization expense of intangible assets recorded in (2) 24 — — (1) Includes $17 million for the year ended December 31, 2019 of amortization expense related to intangibles acquired in the Merger. (2) The fair value of intangible assets, and related amortization assumptions, acquired through acquisitions during the year ended December 31, 2019 , has been finalized. See Note 4 . Year Ended December 31, 2019 2018 2017 (in millions) Amortization expense of intangible assets recorded in Depreciation and amortization $ 9 $ 10 $ 13
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	CenterPoint Energy and CERC estimate that amortization expense of intangible assets with finite lives for the next five years will be as follows: Amortization Expense CenterPoint Energy CERC (in millions) 2020 $ 29 $ 6 2021 25 6 2022 25 6 2023 24 5 2024 22 5

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2019
Regulated Operations [Abstract]
Schedule of Regulatory Assets and Liabilities [Table Text Block]	The following is a list of regulatory assets and liabilities reflected on the Registrants’ respective Consolidated Balance Sheets as of December 31, 2019 and 2018 . The “amortization through” columns indicate the latest year when a regulatory asset or regulatory liability category will be fully amortized: December 31, 2019 CenterPoint Energy Houston Electric CERC Amortization Through (in millions) Amortization Through (in millions) Amortization Through (in millions) Regulatory Assets: Current regulatory assets (1) 2020 $ 12 n/a $ — 2020 $ 12 Non-current regulatory assets: Securitized regulatory assets 2024 788 2024 788 n/a — Unrecognized equity return (2) 2024 (168 ) 2024 (168 ) n/a — Unamortized loss on reacquired debt (3) 2046 62 2046 62 n/a — Pension and postretirement-related regulatory asset (3) Various (a) 637 TBD (b) 34 Various (a) 22 Hurricane Harvey restoration costs (3) Various 68 TBD (b) 64 TBD (c) 4 Regulatory assets related to TCJA (3) (4) Various 30 TBD (b) 23 2023 7 Asset retirement obligation (3) Perpetual 131 Perpetual 26 Perpetual 94 Other regulatory assets-not earning a return (5) Various (d) 147 Various 57 Various 48 Other regulatory assets Various 422 Various 29 Various 16 Total non-current regulatory assets 2,117 915 191 Total regulatory assets 2,129 915 203 Regulatory Liabilities: Current regulatory liabilities (6) 2020 47 n/a — 2020 47 Non-current regulatory liabilities: Regulatory liabilities related to TCJA (4) Various 1,582 TBD (b) 821 Various 442 Estimated removal costs Various 1,429 Various 244 Various 637 Other regulatory liabilities Various 463 Various 223 Various 140 Total non-current regulatory liabilities 3,474 1,288 1,219 Total regulatory liabilities 3,521 1,288 1,266 Total regulatory assets and liabilities, net $ (1,392 ) $ (373 ) $ (1,063 ) (a) Pension and postretirement-related regulatory assets balances are measured annually, and the ending amortization period may change based on the actuarial valuation. (b) The recovery and amortization of these amounts are to be determined upon receipt of the final order. (c) The recovery and amortization of a portion of these amounts are expected to be determined in the next rate case. (d) Other regulatory assets not-earning a return includes items with different amortization periods; therefore, the amortization is accounted for through various periods. December 31, 2018 CenterPoint Energy Houston Electric CERC (in millions) Regulatory Assets: Current regulatory assets (1) $ 77 $ — $ 77 Non-current regulatory assets: Securitized regulatory assets 1,059 1,059 — Unrecognized equity return (2) (213 ) (213 ) — Unamortized loss on reacquired debt (3) 68 68 — Pension and postretirement-related regulatory asset (3) 725 33 30 Hurricane Harvey restoration costs (3) 68 64 4 Regulatory assets related to TCJA (3) (4) 33 23 10 Asset retirement obligation (3) 109 24 85 Other regulatory assets-not earning a return (3) 81 55 26 Other regulatory assets 37 11 26 Total non-current regulatory assets 1,967 1,124 181 Total regulatory assets 2,044 1,124 258 Regulatory Liabilities: Current regulatory liabilities (6) 38 17 21 Non-current regulatory liabilities: Regulatory liabilities related to TCJA (4) 1,323 847 476 Estimated removal costs 886 269 617 Other regulatory liabilities 316 182 134 Total non-current regulatory liabilities 2,525 1,298 1,227 Total regulatory liabilities 2,563 1,315 1,248 Total regulatory assets and liabilities, net $ (519 ) $ (191 ) $ (990 ) (1) Current regulatory assets are included in Prepaid expenses and other current assets in the Registrants’ respective Consolidated Balance Sheets. (2) The unrecognized equity return will be recognized as it is recovered in rates through 2024. The timing of CenterPoint Energy’s and Houston Electric’s recognition of the equity return will vary each period based on amounts actually collected during the period. The actual amounts recognized are adjusted at least annually to correct any over-collections or under-collections during the preceding 12 months. Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CenterPoint Energy Houston Electric CenterPoint Energy Houston Electric Allowed equity return recognized $ 45 $ 45 $ 74 $ 74 $ 42 $ 42 (3) Substantially all of these regulatory assets are not earning a return. (4) The EDIT and deferred revenues will be recovered or refunded to customers as required by tax and regulatory authorities. See Note 15 for additional information. (5) Regulatory assets acquired in the Merger and not earning a return were recorded at fair value as of the Merger Date. Such fair value adjustments are recognized over time until the regulatory asset is recovered. (6) Current regulatory liabilities are included in Other current liabilities in each of the Registrants’ respective Consolidated Balance Sheets.

Stock-Based Incentive Compens_2

Stock-Based Incentive Compensation Plans and Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]	The following table summarizes CenterPoint Energy’s expenses related to LTIPs for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 (in millions) LTIP Compensation expense (1) $ 28 $ 26 $ 21 Income tax benefit recognized 7 6 8 Actual tax benefit realized for tax deductions 12 5 6 (1) Amounts presented in the table above are included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income and shown prior to any amounts capitalized.
Share-Based Compensation, Activity [Table Text Block]	The following tables summarize CenterPoint Energy’s LTIP activity for 2019 : Year Ended December 31, 2019 Shares (Thousands) Weighted-Average Grant Date Fair Value Remaining Average Contractual Life (Years) Aggregate Intrinsic Value (2) (Millions) Performance Awards (1) Outstanding and non-vested as of December 31, 2018 3,818 $ 23.91 Granted 1,413 31.16 Forfeited or canceled (825 ) 24.78 Vested and released to participants (1,074 ) 18.97 Outstanding and non-vested as of December 31, 2019 3,332 $ 28.36 1.1 $ 53 Stock Unit Awards Outstanding and non-vested as of December 31, 2018 1,060 $ 24.08 Granted 470 31.07 Forfeited or canceled (131 ) 27.95 Vested and released to participants (433 ) 20.72 Outstanding and non-vested as of December 31, 2019 966 $ 28.46 1.2 $ 26 (1) Reflects maximum performance achievement. (2) Reflects the impact of current expectations of achievement and stock price.
Share-Based Compensation Arrangement By Award, Weighted Average Grant Date Fair Value, Grant Date Intrinsic Value, and Vested Grant Date Fair Value [Table Text Block]	The weighted average grant date fair values per unit of awards granted were as follows for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 (In millions, except for per unit amounts) Performance Awards Weighted-average grant date fair value per unit of awards granted $ 31.16 $ 26.74 $ 26.64 Total intrinsic value of awards received by participants 36 12 7 Vested grant date fair value 20 9 5 Stock Unit Awards Weighted-average grant date fair value per unit of awards granted $ 31.07 $ 26.62 $ 26.77 Total intrinsic value of awards received by participants 15 9 9 Vested grant date fair value 9 7 7
Schedule of Multiemployer Plans [Table Text Block]	CenterPoint Energy’s participation in the significant plans is outlined in the following table. The EIN / Pension Plan Number column provides the EIN and three-digit pension plan numbers. The most recent Pension Protection Act Zone Status available in 2019 is for the plan year end at January 31, 2019 for the Central Pension Fund, May 31, 2019 for the Indiana Pension Laborers Fund, December 31, 2018 for the Pipeline Industry Benefit Fund, December 31, 2018 for the Laborers District Council & Contractors’ Pension Fund of Ohio, April 30, 2019 for the Ohio Operating Engineers Pension Fund, April 30, 2019 for the Operating Engineers Local 324 Fringe Benefit Fund, December 31, 2018 for the Minnesota Laborers Pension Fund, and December 31, 2018 for the Laborers’ Combined Fund of Western Pennsylvania. Generally, plans in the red zone are less than 65% funded, plans in the yellow zone are less than 80% funded and plans in the green zone are at least 80% funded. The FIP/RP Status Pending / Implemented column indicates plans for which a FIP or RP is either pending or has been implemented. The multi-employer contributions listed in the table below are CenterPoint Energy’s multi-employer contributions made in 2019.
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Amounts recognized in accumulated other comprehensive loss (gain) consist of the following: December 31, 2019 2018 Pension Benefits Postretirement Benefits Pension Benefits Postretirement Benefits CenterPoint Energy CenterPoint Energy CERC CenterPoint Energy CenterPoint Energy CERC (in millions) Unrecognized actuarial loss (gain) $ 105 $ (16 ) $ (12 ) $ 109 $ (7 ) $ (3 ) Unrecognized prior service cost — 7 7 1 5 5 Deferred tax benefit — — — — — (9 ) Net amount recognized in accumulated other comprehensive loss (gain) $ 105 $ (9 ) $ (5 ) $ 110 $ (2 ) $ (7 ) Changes in accumulated comprehensive income (loss) are as follows: Year Ended December 31, 2019 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Beginning Balance $ (108 ) $ (14 ) $ 5 $ (68 ) $ — $ 6 Other comprehensive income (loss) before reclassifications: Remeasurement of pension and other postretirement plans 7 — 7 (19 ) — 1 Deferred loss from interest rate derivatives (1) (3 ) (1 ) — (19 ) (18 ) (1 ) Reclassified to earnings 1 — — — — — Other comprehensive loss from unconsolidated affiliates (1 ) — — — — — Amounts reclassified from accumulated other comprehensive loss: Prior service cost (2) 1 — — 1 — 1 Actuarial losses (2) 8 — — 6 — — Tax benefit (expense) (3 ) — (2 ) 6 4 (1 ) Net current period other comprehensive income (loss) 10 (1 ) 5 (25 ) (14 ) — Adoption of ASU 2018-02 — — — (15 ) — (1 ) Ending Balance $ (98 ) $ (15 ) $ 10 $ (108 ) $ (14 ) $ 5 (1) Gains and losses are reclassified from Accumulated other comprehensive income into income when the hedged transactions affect earnings. The reclassification amounts are included in Interest and other finance charges in each of the Registrant’s respective Statements of Consolidated Income. Amounts are $1 million and less than $1 million for the years ended December 31, 2019 and 2018 , respectively. (2) Amounts are included in the computation of net periodic cost and are reflected in Other, net in each of the Registrants’ respective Statements of Consolidated Income.
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	The changes in plan assets and benefit obligations recognized in other comprehensive income during 2019 are as follows: Pension Benefits Postretirement Benefits CenterPoint Energy CenterPoint Energy CERC (in millions) Net loss (gain) $ 4 $ (8 ) $ (6 ) Amortization of net loss (8 ) — — Amortization of prior service cost (1 ) 1 (1 ) Total recognized in comprehensive income $ (5 ) $ (7 ) $ (7 ) Total expense recognized in net periodic costs and Other comprehensive income $ 87 $ 1 $ (1 )
Benefit Plan Contributions [Table Text Block]	The Registrants made the following contributions in 2019 and expect to make the following minimum contributions in 2020 to the indicated benefit plans below: Contributions in 2019 Expected Minimum Contributions in 2020 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Qualified pension plans $ 86 $ — $ — $ 76 $ — $ — Non-qualified pension plans 23 — — 7 — — Postretirement benefit plans 17 10 3 17 9 3
Schedule of Expected Benefit Payments [Table Text Block]	The following benefit payments are expected to be paid by the pension and postretirement benefit plans: Pension Benefits Postretirement Benefits CenterPoint Energy CenterPoint Energy Houston Electric CERC (in millions) 2020 $ 180 $ 18 $ 8 $ 5 2021 178 18 8 4 2022 180 19 9 5 2023 181 20 10 5 2024 177 21 10 6 2025-2029 824 112 54 30
Defined Contribution Plan Disclosures [Table Text Block]	CenterPoint Energy allocates the savings plan benefit expense to Houston Electric and CERC related to their respective employees. The following table summarizes the Registrants’ savings plan benefit expense for 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Savings plan benefit expenses (1) $ 58 $ 18 $ 18 $ 43 $ 17 $ 18 $ 41 $ 17 $ 17
Other Benefit Plans [Table Text Block]	Expenses related to other benefit plans were recorded as follows: Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Postemployment benefits $ 2 $ 1 $ 1 $ 3 $ 4 $ 1 $ 6 $ 1 $ 4 Deferred compensation plans 4 1 — 3 1 — 3 1 — Amounts related to other benefit plans were included in Benefit Obligations in the Registrants’ accompanying Consolidated Balance Sheets as follows: December 31, 2019 December 31, 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Postemployment benefits $ 11 $ 3 $ 7 $ 11 $ 3 $ 7 Deferred compensation plans 41 8 3 42 9 3 Split-dollar life insurance arrangements 32 1 — 36 1 —
Other Employee Matters [Table Text Block]	As of December 31, 2019 , the Registrants’ employees were covered by collective bargaining agreements as follows: Percentage of Employees Covered Agreement Expiration CenterPoint Energy Houston Electric CERC IBEW Local 66 May 2020 10 % 51 % — OPEIU Local 12 and Mankato March and May 2021 2 % — 3 % Gas Workers Union Local 340 April 2020 3 % — 12 % IBEW Locals 949 & 1393 and USW Locals 12213 & 7441 December 2020 4 % — 7 % USW Locals 13-227 & 13-1 and IBEW Local 702 June and July 2022 5 % — 12 % Teamsters Local 135 September 2021 — — — UWUA Local 175 October 2021 1 % — — Trade Agreements of Infrastructure Services through the DCA and PLCA (1) Various expiration dates in 2020 – 2022 27 % — — Total 52 % 51 % 34 % (1) Infrastructure Services negotiates various trade agreements through contractor associations. The two primary associations are the DCA and the PLCA. These trade agreements are with a variety of construction unions including Laborer’s International Union of North America, International Union of Operating Engineers, United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry, and Teamsters. The trade agreements have varying expiration dates in 2020, 2021 and 2022. In addition, these subsidiaries have various project agreements and small local agreements. These agreements expire upon completion of a specific project or on various dates throughout the year.
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	CenterPoint Energy’s net periodic cost includes the following components relating to pension, including the non-qualified benefit plans: Year Ended December 31, 2019 2018 2017 (in millions) Service cost (1) $ 40 $ 37 $ 36 Interest cost (2) 96 79 89 Expected return on plan assets (2) (105 ) (107 ) (97 ) Amortization of prior service cost (2) 9 9 9 Amortization of net loss (2) 52 43 58 Settlement cost (2) (3) 2 — — Curtailment gain (2) (4) (1 ) — — Net periodic cost $ 93 $ 61 $ 95 (1) Amounts presented in the table above are included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income, net of regulatory deferrals and amounts capitalized. (2) Amounts presented in the table above are included in Other, net in CenterPoint Energy’s Statements of Consolidated Income, net of regulatory deferrals. (3) A one-time, non-cash settlement cost is required when the total lump sum distributions or other settlements of plan benefit obligations during a plan year exceed the service cost and interest cost components of the net periodic cost for that year. In 2019, CenterPoint Energy recognized a non-cash settlement cost due to lump sum settlement payments. (4) A curtailment gain or loss is required when the expected future services of a significant number of employees are reduced or eliminated for the accrual of benefits. In 2019, CenterPoint Energy recognized a pension curtailment gain related to employees who were terminated after the Merger closed.
Schedule of Assumptions Used [Table Text Block]	CenterPoint Energy used the following assumptions to determine net periodic cost relating to pension benefits: Year Ended December 31, 2019 2018 2017 Discount rate 4.35 % 3.65 % 4.15 % Expected return on plan assets 6.00 6.00 6.00 Rate of increase in compensation levels 4.60 4.45 4.50
Schedule of Net Pension and Post-retirement Benefit Costs [Table Text Block]	The following table summarizes changes in the benefit obligation, plan assets, the amounts recognized in the Consolidated Balance Sheets as well as the key assumptions of CenterPoint Energy’s pension plans. The measurement dates for plan assets and obligations were December 31, 2019 and 2018 . December 31, 2019 2018 (in millions, except for actuarial assumptions) Change in Benefit Obligation Benefit obligation, beginning of year $ 2,013 $ 2,225 Plan obligations assumed in Merger 332 — Service cost 40 37 Interest cost 96 79 Benefits paid (244 ) (201 ) Actuarial (gain) loss (1) 216 (127 ) Plan amendment 1 — Curtailment (1 ) — Benefit obligation, end of year 2,453 2,013 Change in Plan Assets Fair value of plan assets, beginning of year 1,516 1,801 Plan assets assumed in Merger 286 — Employer contributions 109 69 Benefits paid (244 ) (201 ) Actual investment return 338 (153 ) Fair value of plan assets, end of year 2,005 1,516 Funded status, end of year $ (448 ) $ (497 ) Amounts Recognized in Balance Sheets Current liabilities-other $ (8 ) $ (7 ) Other liabilities-benefit obligations (440 ) (490 ) Net liability, end of year $ (448 ) $ (497 ) Actuarial Assumptions Discount rate (2) 3.20 % 4.35 % Expected return on plan assets (3) 5.75 6.00 Rate of increase in compensation levels 4.95 4.60 Interest crediting rate 3.25 3.75 (1) Significant sources of loss for 2019 include the decrease in discount rate from 4.35% to 3.20% . Significant sources of gain for 2018 include the increase in discount rate from 3.65% to 4.35% and the mortality projection scale change from MP2017 to MP2018. (2) The discount rate assumption was determined by matching the projected cash flows of CenterPoint Energy’s plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years. (3) The expected rate of return assumption was developed using the targeted asset allocation of CenterPoint Energy’s plans and the expected return for each asset class.
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]	The following table displays pension benefits related to CenterPoint Energy’s pension plans that have accumulated benefit obligations in excess of plan assets: December 31, 2019 2018 Pension (Qualified) Pension (Non-qualified) Pension Pension (in millions) Accumulated benefit obligation $ 2,352 $ 68 $ 1,930 $ 61 Projected benefit obligation 2,385 68 1,952 61 Fair value of plan assets 2,005 — 1,516 —
Target Allocation of Plan Assets [Table Text Block]	As part of the investment strategy discussed above, CenterPoint Energy maintained the following weighted average allocation targets for its pension plans as of December 31, 2019 : Minimum Maximum U.S. equity 19 % 29 % International equity 8 % 18 % Real estate 3 % 9 % Fixed income 52 % 62 % Cash 0 % 2 %
Schedule of Allocation of Plan Assets [Table Text Block]	The following tables set forth by level, within the fair value hierarchy (see Note 10 ), CenterPoint Energy’s pension plan assets at fair value as of December 31, 2019 and 2018 : Fair Value Measurements as of December 31, 2019 2018 (Level 1) (Level 2) (Level 3) Total (Level 1) (Level 2) (Level 3) Total (in millions) Cash $ (7 ) $ — $ — $ (7 ) $ 19 $ — $ — $ 19 Corporate bonds: Investment grade or above — 699 — 699 — 368 — 368 Equity securities: U.S. companies 69 — — 69 60 — — 60 Cash received as collateral from securities lending 61 — — 61 77 — — 77 U.S. treasuries 232 — — 232 196 — — 196 Mortgage backed securities — 8 — 8 — 6 — 6 Asset backed securities — 3 — 3 — 1 — 1 Municipal bonds — 44 — 44 — 27 — 27 Mutual funds (2) 270 — — 270 167 — — 167 International government bonds — 21 — 21 — 16 — 16 Obligation to return cash received as collateral from securities lending (61 ) — — (61 ) (77 ) — — (77 ) Total investments at fair value $ 564 $ 775 $ — $ 1,339 $ 442 $ 418 $ — $ 860 Investments measured by net asset value per share or its equivalent (1) (2) 666 656 Total Investments $ 2,005 $ 1,516 (1) Represents investments in common collective trust funds. (2) The amounts invested in mutual funds and common collective trust funds were allocated as follows: As of December 31, 2019 2018 Mutual Funds Common Collective Trust Funds Mutual Funds Common Collective Trust Funds International equities (1) 31 % 29 % 85 % 41 % U.S. equities 49 % 51 % 15 % 5 % Real estate 1 % 6 % — % — % Fixed income 19 % 14 % — % 54 %
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs [Table Text Block]	Postretirement benefits are accrued over the active service period of employees. The net postretirement benefit cost includes the following components: Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Service cost (1) $ 3 $ 1 $ 1 $ 2 $ — $ 1 $ 2 $ 1 $ 1 Interest cost (2) 15 7 5 13 8 4 16 9 5 Expected return on plan assets (2) (5 ) (4 ) (1 ) (5 ) (4 ) (1 ) (5 ) (4 ) (1 ) Amortization of prior service cost (credit) (2) (5 ) (6 ) 1 (5 ) (5 ) 1 (5 ) (6 ) 1 Net postretirement benefit cost (credit) $ 8 $ (2 ) $ 6 $ 5 $ (1 ) $ 5 $ 8 $ — $ 6 (1) Amounts presented in the table above are included in Operation and maintenance expense in each of the Registrants’ respective Statements of Consolidated Income, net of regulatory deferrals and amounts capitalized. (2) Amounts presented in the table above are included in Other, net in each of the Registrants’ respective Statements of Consolidated Income, net of regulatory deferrals.
Schedule of Assumptions Used [Table Text Block]	The following assumptions were used to determine net periodic cost relating to postretirement benefits: Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC Discount rate 3.20 % 3.20 % 3.20 % 3.60 % 3.60 % 3.60 % 4.15 % 4.15 % 4.15 % Expected return on plan assets 4.60 4.70 4.15 4.55 4.75 3.85 4.50 4.75 3.60
Schedule of Net Pension and Post-retirement Benefit Costs [Table Text Block]	The following table summarizes changes in the benefit obligation, plan assets, the amounts recognized in consolidated balance sheets and the key assumptions of the postretirement plans. The measurement dates for plan assets and benefit obligations were December 31, 2019 and 2018 . December 31, 2019 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Change in Benefit Obligation Benefit obligation, beginning of year $ 331 $ 166 $ 110 $ 386 $ 225 $ 109 Plan obligations assumed in Merger 37 — — — — — Service cost 3 1 1 2 — 1 Interest cost 15 7 5 13 8 4 Participant contributions 8 2 4 7 2 4 Benefits paid (26 ) (13 ) (8 ) (25 ) (13 ) (9 ) Plan amendment 9 3 5 — — — Actuarial (gain) loss (1) (21 ) (4 ) (15 ) (52 ) (56 ) 1 Benefit obligation, end of year 356 162 102 331 166 110 Change in Plan Assets Fair value of plan assets, beginning of year 114 89 25 120 93 26 Employer contributions 17 10 3 14 9 4 Participant contributions 8 2 4 7 2 4 Benefits paid (26 ) (13 ) (8 ) (25 ) (13 ) (9 ) Actual investment return 15 13 3 (2 ) (2 ) — Fair value of plan assets, end of year 128 101 27 114 89 25 Funded status, end of year $ (228 ) $ (61 ) $ (75 ) $ (217 ) $ (77 ) $ (85 ) Amounts Recognized in Balance Sheets Current liabilities-other $ (8 ) $ — $ (3 ) $ (6 ) $ — $ (3 ) Other liabilities-benefit obligations (220 ) (61 ) (72 ) (211 ) (77 ) (82 ) Net liability, end of year $ (228 ) $ (61 ) $ (75 ) $ (217 ) $ (77 ) $ (85 ) Actuarial Assumptions Discount rate (2) 3.25 % 3.25 % 3.25 % 4.35 % 4.35 % 4.35 % Expected return on plan assets (3) 3.95 4.05 3.35 4.60 4.70 4.15 Medical cost trend rate assumed for the next year - Pre-65 5.50 5.50 5.50 5.95 5.95 5.95 Medical/prescription drug cost trend rate assumed for the next year - Post-65 5.75 5.75 5.75 28.60 28.60 28.60 Prescription drug cost trend rate assumed for the next year - Pre-65 8.00 8.00 8.00 9.20 9.20 9.20 Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 4.50 4.50 4.50 4.50 4.50 4.50 Year that the cost trend rates reach the ultimate trend rate - Pre-65 2028 2028 2028 2026 2026 2026 Year that the cost trend rates reach the ultimate trend rate - Post-65 2029 2029 2029 2027 2027 2027 (1) Significant sources of gain for 2019 include favorable cost trend rates and benefit claims experience in addition to the change in mortality projection scale from MP2018 to MP2019. Significant sources of gain for 2018 include the increase in the discount rate from 3.60% to 4.35% , favorable benefit claims experience and cost trend rates in addition to the change in mortality projection scale from MP2017 to MP2018. (2) The discount rate assumption was determined by matching the projected cash flows of the plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years. (3) The expected rate of return assumption was developed using the targeted asset allocation of the plans and the expected return for each asset class.
Target Allocation of Plan Assets [Table Text Block]	As part of the investment strategy discussed above, the Registrants maintained the following weighted average allocation targets for the postretirement plans as of December 31, 2019 : CenterPoint Energy Houston Electric CERC Minimum Maximum Minimum Maximum Minimum Maximum U.S. equity 13 % 23 % 13 % 23 % 15 % 25 % International equity 3 % 13 % 3 % 13 % 2 % 12 % Fixed income 69 % 79 % 69 % 79 % 68 % 78 % Cash 0 % 2 % 0 % 2 % 0 % 2 %
Schedule of Allocation of Plan Assets [Table Text Block]	The following table presents mutual funds by level, within the fair value hierarchy, the Registrants’ postretirement plan assets at fair value as of December 31, 2019 and 2018 : Fair Value Measurements as of December 31, 2019 2018 Mutual Funds (Level 1) (Level 2) (Level 3) Total Total (in millions) CenterPoint Energy $ 128 $ — $ — $ 128 $ 114 $ — $ — $ 114 Houston Electric 101 — — 101 89 — — 89 CERC 27 — — 27 25 — — 25 The amounts invested in mutual funds were allocated as follows: As of December 31, 2019 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC Fixed income 71 % 71 % 69 % 74 % 74 % 73 % U.S. equities 21 % 21 % 24 % 19 % 19 % 21 % International equities 8 % 8 % 7 % 7 % 7 % 6 %

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The table below summarizes the Registrants’ outstanding interest rate hedging activity: December 31, 2019 December 31, 2018 Hedging Classification Notional Principal CenterPoint Energy (1) Houston Electric CenterPoint Energy Houston Electric (in millions) Economic hedge $ 84 $ — $ — $ — Cash flow hedge — — 450 450 (1) Relates to interest rate derivative instruments at SIGECO.
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The tables below summarizes CenterPoint Energy’s and CERC’s weather hedge gain (loss) activity: CenterPoint Energy Year Ended December 31, Texas Operations Winter Season Bilateral Cap 2019 2018 2017 (in millions) NGD 2019 – 2020 $ 8 $ 2 $ — $ — NGD 2018 – 2019 9 — — — NGD 2017 – 2018 8 — (2 ) — Electric operations 2019 – 2020 7 3 — — Electric operations 2018 – 2019 8 3 — — Electric operations 2017 – 2018 9 — (2 ) — Electric operations 2016 – 2017 9 — — (1 ) Total CenterPoint Energy (1) $ 8 $ (4 ) $ (1 ) CERC Year Ended December 31, Texas Operations Winter Season Bilateral Cap 2019 2018 2017 (in millions) NGD 2019 – 2020 $ 8 $ 2 $ — $ — NGD 2018 – 2019 9 — — — NGD 2017 – 2018 8 — (2 ) — Total CERC (1) $ 2 $ (2 ) $ — (1) Weather hedge gains (losses) are recorded in Revenues in the Statements of Consolidated Income.
Fair Value of Derivative Instruments [Table Text Block]	The following tables present information about derivative instruments and hedging activities. The first three tables provide a balance sheet overview of Derivative Assets and Liabilities as of December 31, 2019 and 2018 , while the last two tables provide a breakdown of the related income statement impacts for the years ending December 31, 2019 , 2018 and 2017 . Fair Value of Derivative Instruments and Hedged Items CenterPoint Energy December 31, 2019 December 31, 2018 Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Derivatives designated as cash flow hedges: Interest rate derivatives Current Liabilities: Non-trading derivative liabilities $ — $ — $ — $ 24 Derivatives designated as fair value hedges: Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities 12 — 1 7 Derivatives not designated as hedging instruments: Natural gas derivatives (1) (2) (3) Current Assets: Non-trading derivative assets 139 3 103 3 Natural gas derivatives (1) (2) (3) Other Assets: Non-trading derivative assets 58 — 38 — Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities 73 184 62 173 Natural gas derivatives (1) (2) (3) Other Liabilities: Non-trading derivative liabilities 10 54 16 25 Interest rate derivatives Other Liabilities — 10 — — Indexed debt securities derivative Current Liabilities — 893 — 601 Total CenterPoint Energy $ 292 $ 1,144 $ 220 $ 833 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 2,226 Bcf or a net 374 Bcf long position and 1,674 Bcf or a net 140 Bcf long position as of December 31, 2019 and 2018 , respectively. Certain natural gas contracts hedge basis risk only and lack a fixed price exposure. (2) Natural gas contracts are presented on a net basis in CenterPoint Energy’s Consolidated Balance Sheets as they are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within CenterPoint Energy’s Consolidated Balance Sheets. The net of total non-trading natural gas derivative assets and liabilities is detailed in the Offsetting of Natural Gas Derivative Assets and Liabilities table below. (3) Derivative Assets and Derivative Liabilities include no material amounts related to physical forward transactions with Enable. Houston Electric December 31, 2019 December 31, 2018 Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Derivatives designated as cash flow hedges: Interest rate derivatives Current Liabilities: Non-trading derivative liabilities $ — $ — $ — $ 24 Total Houston Electric $ — $ — $ — $ 24 CERC December 31, 2019 December 31, 2018 Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Derivatives designated as fair value hedges: Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities $ 12 $ — $ 1 $ 7 Derivatives not designated as hedging instruments: Natural gas derivatives (1) (2) (3) Current Assets: Non-trading derivative assets 139 3 103 3 Natural gas derivatives (1) (2) (3) Other Assets: Non-trading derivative assets 58 — 38 — Natural gas derivatives (1) (2) (3) Current Liabilities: Non-trading derivative liabilities 73 177 62 173 Natural gas derivatives (1) (2) (3) Other Liabilities: Non-trading derivative liabilities 10 39 16 25 Total CERC $ 292 $ 219 $ 220 $ 208 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 2,226 Bcf or a net 374 Bcf long position and 1,674 Bcf or a net 140 Bcf long position as of December 31, 2019 and 2018 , respectively. Certain natural gas contracts hedge basis risk only and lack a fixed price exposure. (2) Natural gas contracts are presented on a net basis in CERC’s Consolidated Balance Sheets as they are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within CERC’s Consolidated Balance Sheets. The net of total non-trading natural gas derivative assets and liabilities is detailed in the Offsetting of Natural Gas Derivative Assets and Liabilities table below. (3) Derivative Assets and Derivative Liabilities include no material amounts related to physical forward transactions with Enable. Cumulative Basis Adjustment for Fair Value Hedges (CenterPoint Energy and CERC) CenterPoint Energy December 31, 2019 December 31, 2018 Balance Sheet Location Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item (in millions) Hedged items in fair value hedge relationship: Natural gas inventory Current Assets: Natural gas inventory $ 47 $ (13 ) $ 57 $ 1 Total CenterPoint Energy $ 47 $ (13 ) $ 57 $ 1 CERC December 31, 2019 December 31, 2018 Balance Sheet Location Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item Carrying Amount of Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item (in millions) Hedged items in fair value hedge relationship: Natural gas inventory Current Assets: Natural gas inventory $ 47 $ (13 ) $ 57 $ 1 Total CERC $ 47 $ (13 ) $ 57 $ 1
Offsetting of Natural Gas Derivative Assets and Liabilities [Table Text Block]	CenterPoint Energy December 31, 2019 December 31, 2018 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 224 $ (88 ) $ 136 $ 166 $ (66 ) $ 100 Other Assets: Non-trading derivative assets 68 (10 ) 58 54 (16 ) 38 Current Liabilities: Non-trading derivative liabilities (187 ) 136 (51 ) (183 ) 81 (102 ) Other Liabilities: Non-trading derivative liabilities (54 ) 25 (29 ) (25 ) 20 (5 ) Total CenterPoint Energy $ 51 $ 63 $ 114 $ 12 $ 19 $ 31 CERC December 31, 2019 December 31, 2018 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 224 $ (88 ) $ 136 $ 166 $ (66 ) $ 100 Other Assets: Non-trading derivative assets 68 (10 ) 58 54 (16 ) 38 Current Liabilities: Non-trading derivative liabilities (180 ) 136 (44 ) (183 ) 81 (102 ) Other Liabilities: Non-trading derivative liabilities (39 ) 25 (14 ) (25 ) 20 (5 ) Total CERC $ 73 $ 63 $ 136 $ 12 $ 19 $ 31 (1) Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements. (2) The derivative assets and liabilities on the Registrant’s respective Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.
Income Statement Impact of Derivative Activity [Table Text Block]	Income Statement Impact of Hedge Accounting Activity (CenterPoint Energy and CERC) CenterPoint Energy Year Ended December 31, 2019 2018 2017 Location and Amount of Gain (Loss) recognized in Income on Hedging Relationship (1) Non-utility cost of revenues, including natural gas (in millions) Total amounts presented in the statements of income in which the effects of hedges are recorded $ 4,029 $ 4,364 $ 3,785 Gain (loss) on fair value hedging relationships: Commodity contracts: Hedged items - Natural gas inventory (14 ) (13 ) 14 Derivatives designated as hedging instruments 14 13 (14 ) Amounts excluded from effectiveness testing recognized in earnings immediately (213 ) (149 ) (67 ) (1) Income statement impact associated with cash flow hedge activity is related to gains and losses reclassified from Accumulated other comprehensive income into income. Amounts are immaterial for the years ended December 31, 2019 , 2018 and 2017 , respectively. CERC Year Ended December 31, 2019 2018 2017 Location and Amount of Gain (Loss) recognized in Income on Hedging Relationship (1) Non-utility cost of revenues, including natural gas (in millions) Total amounts presented in the statements of income in which the effects of hedges are recorded $ 3,503 $ 4,364 $ 3,785 Gain (loss) on fair value hedging relationships: Commodity contracts: Hedged items - Natural gas inventory (14 ) (13 ) 14 Derivatives designated as hedging instruments 14 13 (14 ) Amounts excluded from effectiveness testing recognized in earnings immediately (213 ) (149 ) (67 ) (1) Income statement impact associated with cash flow hedge activity is related to gains and losses reclassified from Accumulated other comprehensive income into income. Amounts are immaterial for the years ended December 31, 2019 , 2018 and 2017 , respectively. CenterPoint Energy Year Ended December 31, Income Statement Location 2019 2018 2017 (in millions) Effects of derivatives not designated as hedging instruments on the income statement: Commodity contracts Gains (Losses) in Non-utility revenues $ 214 $ 107 $ 211 Indexed debt securities derivative Gain (loss) on indexed debt securities (292 ) (232 ) 49 Interest rate derivatives Gains in Other Income (Expense) — 2 — Total CenterPoint Energy $ (78 ) $ (123 ) $ 260 CERC Year Ended December 31, Income Statement Location 2019 2018 2017 (in millions) Effects of derivatives not designated as hedging instruments on the income statement: Commodity contracts Gains (Losses) in Non-utility revenues $ 214 $ 107 $ 211 Total CERC $ 214 $ 107 $ 211
Credit Quality of Counterparties [Table Text Block]	CenterPoint Energy and CERC enter into financial derivative contracts containing material adverse change provisions. These provisions could require CenterPoint Energy or CERC to post additional collateral if the S&P or Moody’s credit ratings of CenterPoint Energy, Inc. or its subsidiaries, including CERC Corp., are downgraded. December 31, 2019 December 31, 2018 CenterPoint Energy CERC CenterPoint Energy CERC (in millions) Aggregate fair value of derivatives containing material adverse change provisions in a net liability position $ 1 $ 1 $ 1 $ 1 Fair value of collateral already posted — — — — Additional collateral required to be posted if credit risk contingent features triggered 1 1 — — (d) Credit Quality of Counterparties (CenterPoint Energy and CERC) In addition to the risk associated with price movements, credit risk is also inherent in CenterPoint Energy’s and CERC’s non-trading derivative activities. Credit risk relates to the risk of loss resulting from non-performance of contractual obligations by a counterparty. The following tables show the composition of counterparties to the non-trading derivative assets: CenterPoint Energy December 31, 2019 December 31, 2018 Investment Grade (1) Total (3) Investment Grade (1) Total (3) (in millions) Energy marketers $ 4 $ 16 $ 11 $ 24 End users (2) 27 178 30 114 Total CenterPoint Energy $ 31 $ 194 $ 41 $ 138 CERC December 31, 2019 December 31, 2018 Investment Grade (1) Total (3) Investment Grade (1) Total (3) (in millions) Energy marketers $ 4 $ 16 $ 11 $ 24 End users (2) 27 178 30 114 Total CERC $ 31 $ 194 $ 41 $ 138 (1) “Investment grade” is primarily determined using publicly available credit ratings and considers credit support (including parent company guarantees) and collateral (including cash and standby letters of credit). For unrated counterparties, CERC determines a synthetic credit rating by performing financial statement analysis and consider contractual rights and restrictions and collateral. (2) End users are comprised primarily of customers who have contracted to fix the price of a portion of their physical gas requirements for future periods. (3) The amounts reflected in the table above were not impacted by collateral netting.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on a Recurring Basis [Table Text Block]	The following tables present information about the Registrants’ assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis as of December 31, 2019 and December 31, 2018 , and indicate the fair value hierarchy of the valuation techniques utilized by the Registrants to determine such fair value. CenterPoint Energy December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Netting (1) Total Level 1 Level 2 Level 3 Netting (1) Total Assets (in millions) Corporate equities $ 825 $ — $ — $ — $ 825 $ 542 $ — $ — $ — $ 542 Investments, including money market funds (2) 49 — — — 49 66 — — — 66 Natural gas derivatives (3)(4) — 250 42 (98 ) 194 — 173 47 (82 ) 138 Hedged portion of natural gas inventory — — — — — 1 — — — 1 Total assets $ 874 $ 250 $ 42 $ (98 ) $ 1,068 $ 609 $ 173 $ 47 $ (82 ) $ 747 December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Netting (1) Total Level 1 Level 2 Level 3 Netting (1) Total Liabilities Indexed debt securities derivative $ — $ 893 $ — $ — $ 893 $ — $ 601 $ — $ — $ 601 Interest rate derivatives — 10 — — 10 24 — — — 24 Natural gas derivatives (3)(4) — 217 24 (161 ) 80 — 191 17 (101 ) 107 Hedged portion of natural gas inventory 13 — — — 13 — — — — — Total liabilities $ 13 $ 1,120 $ 24 $ (161 ) $ 996 $ 24 $ 792 $ 17 $ (101 ) $ 732 Houston Electric December 31, 2019 December 31, 2018 Level 1 Level 2 Level 3 Netting Total Level 1 Level 2 Level 3 Netting Total Assets (in millions) Investments, including money market funds (2) $ 32 $ — $ — $ — $ 32 $ 48 $ — $ — $ — $ 48 Total assets $ 32 $ — $ — $ — $ 32 $ 48 $ — $ — $ — $ 48 Liabilities Interest rate derivatives $ — $ — $ — $ — $ — $ 24 $ — $ — $ — $ 24 Total liabilities $ — $ — $ — $ — $ — $ 24 $ — $ — $ — $ 24 CERC December 31, 2019 December 31, 2018 Level 2 Level 3 Netting (1) Total Level 2 Level 3 Netting (1) Total Assets (in millions) Corporate equities $ 2 $ — $ — $ — $ 2 $ 2 $ — $ — $ — $ 2 Investments, including money market funds (2) 11 — — — 11 11 — — — 11 Natural gas derivatives (3)(4) — 250 42 (98 ) 194 — 173 47 (82 ) 138 Hedged portion of natural gas inventory — — — — — 1 — — — 1 Total assets $ 13 $ 250 $ 42 $ (98 ) $ 207 $ 14 $ 173 $ 47 $ (82 ) $ 152 Liabilities Natural gas derivatives (3)(4) $ — $ 195 $ 24 $ (161 ) $ 58 $ — $ 191 $ 17 $ (101 ) $ 107 Hedged portion of natural gas inventory 13 — — — 13 — — — — — Total liabilities $ 13 $ 195 $ 24 $ (161 ) $ 71 $ — $ 191 $ 17 $ (101 ) $ 107 (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy and CERC to settle positive and negative positions and also include cash collateral posted with the same counterparties as follows: December 31, 2019 December 31, 2018 CenterPoint Energy CERC CenterPoint Energy CERC (in millions) Cash collateral posted with the same counterparties $ 63 $ 63 $ 19 $ 19 (2) Amounts are included in Prepaid and Other Current Assets and Other Assets in the Consolidated Balance Sheets. (3) Natural gas derivatives include no material amounts related to physical forward transactions with Enable. (4) Level 1 natural gas derivatives include exchange-traded derivatives cleared by the CME, which deems that financial instruments cleared by the CME are settled daily in connection with posted cash payments. As a result of this exchange rule, CME-related derivatives are considered to have no fair value at the balance sheet date for financial reporting purposes, and are presented in Level 1 net of posted cash; however, the derivatives remain outstanding and subject to future commodity price fluctuations until they are settled in accordance with their contractual terms. Derivative transactions cleared on exchanges other than the CME (e.g., the Intercontinental Exchange or ICE) continue to be reported on a gross basis.
Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs [Table Text Block]	The following table presents additional information about assets or liabilities, including derivatives that are measured at fair value on a recurring basis for which CenterPoint Energy and CERC have utilized Level 3 inputs to determine fair value: Year Ended December 31, 2019 2018 2017 CenterPoint Energy CERC CenterPoint Energy CERC CenterPoint Energy CERC (in millions) Beginning balance $ 30 $ 30 $ (622 ) $ 46 $ (704 ) $ 13 Total gains 17 17 30 30 96 47 Total settlements (22 ) (22 ) (39 ) (39 ) (11 ) (11 ) Transfers into Level 3 (1 ) (1 ) 5 5 14 14 Transfers out of Level 3 (1) (6 ) (6 ) 656 (12 ) (17 ) (17 ) Ending balance (2) $ 18 $ 18 $ 30 $ 30 $ (622 ) $ 46 The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date: $ 12 $ 12 $ 18 $ 18 $ 87 $ 38 (1) During 2018, CenterPoint Energy transferred its indexed debt securities derivative from Level 3 to Level 2 to reflect changes in the significance of the unobservable inputs used in the valuation. (2) CenterPoint Energy and CERC did not have significant Level 3 purchases or sales during any of the years ended December 31, 2019 , 2018 or 2017.
Estimated Fair Value of Financial Instruments, Debt Instruments [Table Text Block]	The fair values of cash and cash equivalents, investments in debt and equity securities classified as “trading” and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. The carrying amounts of non-trading derivative assets and liabilities and CenterPoint Energy’s ZENS indexed debt securities derivative are stated at fair value and are excluded from the table below. The fair value of each debt instrument is determined by multiplying the principal amount of each debt instrument by a combination of historical trading prices and comparable issue data. These liabilities, which are not measured at fair value in the Registrants’ Consolidated Balance Sheets, but for which the fair value is disclosed, would be classified as Level 2 in the fair value hierarchy. December 31, 2019 December 31, 2018 CenterPoint Energy (1) Houston Electric (1) CERC CenterPoint Energy (1) Houston Electric (1) CERC Long-term debt, including current maturities (in millions) Carrying amount $ 15,093 $ 4,950 $ 2,546 $ 9,140 $ 4,717 $ 2,371 Fair value 16,067 5,457 2,803 9,308 4,770 2,488 (1) Includes Securitization Bond debt.

Unconsolidated Affiliate (Cen_2

Unconsolidated Affiliate (CenterPoint Energy and CERC) (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments [Table Text Block]	Limited Partner Interest and Units Held in Enable (CenterPoint Energy): As of December 31, 2019 2018 Limited Partner Interest (1) Common Units Enable Series A Preferred Units (2) Limited Partner Interest (1) Common Units Enable Series A Preferred Units (2) CenterPoint Energy (3) 53.7 % 233,856,623 14,520,000 54.0 % 233,856,623 14,520,000 OGE 25.5 % 110,982,805 — 25.6 % 110,982,805 — Public unitholders 20.8 % 90,361,937 — 20.4 % 88,392,983 — Total Units Outstanding 100.0 % 435,201,365 14,520,000 100.0 % 433,232,411 14,520,000 (1) Excludes the Enable Series A Preferred Units owned by CenterPoint Energy. (2) The carrying amount of the Enable Series A Preferred Units, reflected as Preferred units - unconsolidated affiliate on CenterPoint Energy’s Consolidated Balance Sheets, was $363 million as of both December 31, 2019 and 2018 . No impairment charges or adjustment to carrying value were made as no observable price changes were identified in the current or prior reporting periods. (3) Prior to the Internal Spin completed in September 2018, CenterPoint Energy’s investment in Enable’s common units, excluding the Enable Series A Preferred Units held directly by CenterPoint Energy, was held indirectly through CERC. Interests Held in Enable GP (CenterPoint Energy): CenterPoint Energy and OGE held the following interests in Enable GP as of both December 31, 2019 and 2018 : Management Rights (1) Incentive Distribution Rights (2) CenterPoint Energy (3) 50 % 40 % OGE 50 % 60 % (1) As of December 31, 2019 , Enable is controlled jointly by CenterPoint Energy and OGE. Sale of CenterPoint Energy’s or OGE’s ownership interests in Enable GP to a third party is subject to mutual rights of first offer and first refusal, and CenterPoint Energy is not permitted to dispose of less than all of its interest in Enable GP. (2) Enable is expected to pay a minimum quarterly distribution of $0.2875 per common unit on its outstanding common units to the extent it has sufficient cash from operations after establishment of cash reserves and payment of fees and expenses, including payments to Enable GP and its affiliates, within 60 days after the end of each quarter. If cash distributions to Enable’s unitholders exceed $0.330625 per common unit in any quarter, Enable GP will receive increasing percentages or incentive distributions rights, up to 50% , of the cash Enable distributes in excess of that amount. In certain circumstances Enable GP will have the right to reset the minimum quarterly distribution and the target distribution levels at which the incentive distributions receive increasing percentages to higher levels based on Enable’s cash distributions at the time of the exercise of this reset election. To date, no incentive distributions have been made. (3) Held indirectly through CNP Midstream. Distributions Received from Enable (CenterPoint Energy and CERC): CenterPoint Energy Year Ended December 31, 2019 2018 2017 Per Unit Cash Distribution Per Unit Cash Distribution Per Unit Cash Distribution (in millions, except per unit amounts) Enable common units (1) $ 1.2970 $ 303 $ 1.2720 $ 297 $ 1.2720 $ 297 Enable Series A Preferred Units 2.5000 36 2.5000 36 2.5000 36 Total CenterPoint Energy $ 339 $ 333 $ 333 CERC Year Ended December 31, 2018 2017 Per Unit Cash Distribution Per Unit Cash Distribution (in millions, except per unit amounts) Enable common units (1) $ 0.9540 $ 223 $ 1.2720 $ 297 Total CERC 223 297 (1) Prior to the Internal Spin completed in September 2018, distributions from Enable were received by CERC. After such date, distributions from Enable were received directly by CenterPoint Energy (through CNP Midstream). Transactions with Enable (CenterPoint Energy and CERC): Year Ended December 31, 2019 2018 2017 CenterPoint Energy (in millions) Natural gas expenses, including transportation and storage costs (1) $ 120 $ 122 $ 115 Reimbursement of support services (2) — 4 4 CERC Natural gas expenses, including transportation and storage costs (1) 120 122 115 Reimbursement of support services (2) — 4 4 (1) Included in Non-utility costs of revenues, including natural gas on CenterPoint Energy’s and CERC’s respective Statements of Consolidated Income. (2) Represents amounts billed for certain support services provided to Enable. Actual support services costs are recorded net of reimbursement. December 31, 2019 2018 CenterPoint Energy (in millions) Accounts payable for natural gas purchases from Enable $ 11 $ 11 Accounts receivable for amounts billed for services provided to Enable 2 2 CERC Accounts payable for natural gas purchases from Enable 11 11 Accounts receivable for amounts billed for services provided to Enable 2 2 CERC’s continuing involvement with Enable subsequent to the Internal Spin is limited to its natural gas purchases from Enable. Summarized consolidated income (loss) information for Enable is as follows: Year Ended December 31, 2019 2018 2017 (in millions) Operating revenues $ 2,960 $ 3,431 $ 2,803 Cost of sales, excluding depreciation and amortization 1,279 1,819 1,381 Depreciation and amortization 433 398 366 Operating income 569 648 528 Goodwill impairment 86 — — Net income attributable to Enable common units 360 485 400 Reconciliation of Equity in Earnings (Losses), net: CenterPoint Energy’s interest $ 193 $ 262 $ 216 Basis difference amortization (1) 47 47 49 Loss on dilution, net of proportional basis difference recognition (11 ) (2 ) — CenterPoint Energy’s equity in earnings, net $ 229 $ 307 $ 265 (1) Equity in earnings of unconsolidated affiliate includes CenterPoint Energy’s share of Enable earnings adjusted for the amortization of the basis difference of CenterPoint Energy’s original investment in Enable and its underlying equity in net assets of Enable. The basis difference is being amortized through the year 2048. Summarized consolidated balance sheet information for Enable is as follows: December 31, 2019 2018 (in millions) Current assets $ 389 $ 449 Non-current assets 11,877 11,995 Current liabilities 780 1,615 Non-current liabilities 4,077 3,211 Non-controlling interest 37 38 Preferred equity 362 362 Accumulated other comprehensive loss (3 ) — Enable partners’ equity 7,013 7,218 Reconciliation of Investment in Enable: CenterPoint Energy’s ownership interest in Enable partners’ equity $ 3,767 $ 3,896 CenterPoint Energy’s basis difference (1,361 ) (1,414 ) CenterPoint Energy’s equity method investment in Enable $ 2,406 $ 2,482 Investment in Unconsolidated Affiliates (CenterPoint Energy): December 31, 2019 December 31, 2018 (in millions) Enable $ 2,406 $ 2,482 Other (1) 2 — Total $ 2,408 $ 2,482 (1) Represents the fair value of non-utility equity investments acquired in the Merger. CenterPoint Energy evaluates its equity method investments for impairment when factors indicate that a decrease in value of its investment has occurred and the carrying amount of its investment may not be recoverable. An impairment loss is recognized in earnings when an impairment is deemed to be other than temporary. As of December 31, 2019, CenterPoint Energy’s investment in Enable is $10.29 per unit and Enable’s common unit price closed at $10.03 per unit (approximately $61 million below carrying value). Based on an analysis of its investment in Enable as of December 31, 2019, CenterPoint Energy believes that the decline in the value of its investment is temporary, and that the carrying value of its investment of $2.4 billion will be recovered. Equity in Earnings of Unconsolidated Affiliates, net (CenterPoint Energy): Year Ended December 31, 2019 2018 2017 (in millions) Enable (1) $ 229 $ 307 $ 265 Other 1 — — Total $ 230 $ 307 $ 265 (1) Equity earnings for the year ended December 31, 2019 includes CenterPoint Energy’s share of Enable’s $86 million goodwill impairment recorded in the fourth quarter of 2019.
Disposal Groups, Including Discontinued Operations [Table Text Block]	The Internal Spin represents a significant strategic shift that has a material effect on CERC’s operations and financial results and, as a result, CERC’s distribution of its equity investment in Enable met the criteria for discontinued operations classification. CERC has no continuing involvement in the equity investment of Enable. Therefore, CERC’s equity in earnings and related income taxes have been classified as Income from discontinued operations, net of tax, in CERC’s Statements of Consolidated Income for the periods presented. CERC’s equity method investment and related deferred income tax liabilities have been classified as Investment in unconsolidated affiliate - discontinued operations and Deferred income taxes, net - discontinued operations, respectively, in CERC’s Consolidated Balance Sheets for the periods presented. The following table presents amounts included in Income from discontinued operations, net of tax in CERC’s Statements of Consolidated Income. Year Ended December 31, 2018 2017 (in millions) Equity in earnings of unconsolidated affiliate, net $ 184 $ 265 Income tax expense 46 104 Income from discontinued operations, net of tax $ 138 $ 161

Indexed Debt Securities (ZENS_2

Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) (Tables)	12 Months Ended
	Dec. 31, 2019
Indexed Debt Securities [Abstract]
Summarized Financial Information on Investment in Time Warner Securities and Indexed Debt Security Obligation [Table Text Block]	A subsidiary of CenterPoint Energy holds shares of certain securities detailed in the table below, which are classified as trading securities and are expected to be held to facilitate CenterPoint Energy’s ability to meet its obligation under the ZENS. Unrealized gains and losses resulting from changes in the market value of the ZENS-Related Securities are recorded in CenterPoint Energy’s Statements of Consolidated Income. Shares Held at December 31, 2019 2018 AT&T Common 10,212,945 10,212,945 Charter Common 872,503 872,912 CenterPoint Energy’s reference shares for each ZENS consisted of the following: December 31, 2019 2018 (in shares) AT&T Common 0.7185 0.7185 Charter Common 0.061382 0.061382 The following table sets forth summarized financial information regarding CenterPoint Energy’s investment in ZENS-Related Securities and each component of CenterPoint Energy’s ZENS obligation. ZENS-Related Securities Debt Component of ZENS Derivative Component of ZENS (in millions) Balance as of December 31, 2016 $ 953 $ 114 $ 717 Accretion of debt component of ZENS — 27 — 2% interest paid — (17 ) — Distribution to ZENS holders — (2 ) — Gain on indexed debt securities — — (49 ) Gain on ZENS-Related Securities 7 — — Balance as of December 31, 2017 960 122 668 Accretion of debt component of ZENS — 21 — 2% interest paid — (17 ) — Sale of ZENS-Related Securities (398 ) — — Distribution to ZENS holders — (102 ) (46 ) Gain on indexed debt securities — — (21 ) Loss on ZENS-Related Securities (22 ) — — Balance as of December 31, 2018 540 24 601 Accretion of debt component of ZENS — 17 — 2% interest paid — (17 ) — Distribution to ZENS holders — (5 ) — Loss on indexed debt securities — — 292 Gain on ZENS-Related Securities 282 — — Balance as of December 31, 2019 $ 822 $ 19 $ 893

Equity (CenterPoint Energy) (Ta

Equity (CenterPoint Energy) (Tables)	12 Months Ended
	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
Dividends Declared [Table Text Block]	CenterPoint Energy declared dividends on its Common Stock during 2019 , 2018 and 2017 as presented in the table below: Declaration Date Record Date Payment Date Per Share Total (in millions) October 17, 2019 November 21, 2019 December 12, 2019 $ 0.2875 $ 144 July 31, 2019 August 15, 2019 September 12, 2019 0.2875 145 April 25, 2019 May 16, 2019 June 13, 2019 0.2875 144 Total 2019 $ 0.8625 $ 433 December 12, 2018 February 21, 2019 March 14, 2019 $ 0.2875 $ 144 October 23, 2018 November 15, 2018 December 13, 2018 0.2775 139 July 26, 2018 August 16, 2018 September 13, 2018 0.2775 120 April 26, 2018 May 17, 2018 June 14, 2018 0.2775 120 Total 2018 $ 1.1200 $ 523 Declaration Date Record Date Payment Date Per Share Total (in millions) December 13, 2017 February 15, 2018 March 8, 2018 $ 0.2775 $ 120 October 25, 2017 November 16, 2017 December 8, 2017 0.2675 116 July 27, 2017 August 16, 2017 September 8, 2017 0.2675 115 April 27, 2017 May 16, 2017 June 9, 2017 0.2675 115 January 5, 2017 February 16, 2017 March 10, 2017 0.2675 115 Total 2017 $ 1.3475 $ 581 CenterPoint Energy declared dividends on its Series A Preferred Stock during 2019 and 2018 as presented in the table below: Declaration Date Record Date Payment Date Per Share Total (in millions) July 31, 2019 August 15, 2019 September 3, 2019 $ 30.6250 $ 24 Total 2019 $ 30.6250 $ 24 December 12, 2018 February 15, 2019 March 1, 2019 $ 32.1563 $ 26 Total 2018 $ 32.1563 $ 26 CenterPoint Energy declared dividends on its Series B Preferred Stock during 2019 and 2018 as presented in the table below: Declaration Date Record Date Payment Date Per Share Total October 17, 2019 November 15, 2019 December 2, 2019 $ 17.5000 $ 17 July 31, 2019 August 15, 2019 September 3, 2019 17.5000 17 April 25, 2019 May 15, 2019 June 3, 2019 17.5000 17 Total 2019 $ 52.5000 $ 51 December 12, 2018 February 15, 2019 March 1, 2019 $ 17.5000 $ 17 October 23, 2018 November 15, 2018 December 1, 2018 11.6667 11 Total 2018 $ 29.1667 $ 28 There were no Series A Preferred Stock or Series B Preferred Stock outstanding or dividends declared in 2017 . Dividend Requirement on Preferred Stock Year Ended December 31, 2019 2018 2017 (in millions) Series A Preferred Stock $ 49 $ 18 $ — Series B Preferred Stock 68 17 — Total preferred stock dividend requirement $ 117 $ 35 $ —
Convertible Debt [Table Text Block]	The following table illustrates the conversion rate per share of the Series B Preferred Stock, subject to certain anti-dilution adjustments: Applicable Market Value of the Common Stock Conversion Rate per Share of Series B Preferred Stock Greater than $32.6990 (threshold appreciation price) 30.5820 shares of Common Stock Equal to or less than $32.6990 but greater than or equal to $27.2494 Between 30.5820 and 36.6980 shares of Common Stock, determined by dividing $1,000 by the applicable market value Less than $27.2494 (initial price) 36.6980 shares of Common Stock The following table illustrates the conversion rate per depositary share, subject to certain anti-dilution adjustments: Applicable Market Value of the Common Stock Conversion Rate per Depository Share Greater than $32.6990 (threshold appreciation price) 1.5291 shares of Common Stock Equal to or less than $32.6990 but greater than or equal to $27.2494 Between 1.5291 and 1.8349 shares of Common Stock, determined by dividing $50 by the applicable market value Less than $27.2494 (initial price) 1.8349 shares of Common Stock
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Amounts recognized in accumulated other comprehensive loss (gain) consist of the following: December 31, 2019 2018 Pension Benefits Postretirement Benefits Pension Benefits Postretirement Benefits CenterPoint Energy CenterPoint Energy CERC CenterPoint Energy CenterPoint Energy CERC (in millions) Unrecognized actuarial loss (gain) $ 105 $ (16 ) $ (12 ) $ 109 $ (7 ) $ (3 ) Unrecognized prior service cost — 7 7 1 5 5 Deferred tax benefit — — — — — (9 ) Net amount recognized in accumulated other comprehensive loss (gain) $ 105 $ (9 ) $ (5 ) $ 110 $ (2 ) $ (7 ) Changes in accumulated comprehensive income (loss) are as follows: Year Ended December 31, 2019 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Beginning Balance $ (108 ) $ (14 ) $ 5 $ (68 ) $ — $ 6 Other comprehensive income (loss) before reclassifications: Remeasurement of pension and other postretirement plans 7 — 7 (19 ) — 1 Deferred loss from interest rate derivatives (1) (3 ) (1 ) — (19 ) (18 ) (1 ) Reclassified to earnings 1 — — — — — Other comprehensive loss from unconsolidated affiliates (1 ) — — — — — Amounts reclassified from accumulated other comprehensive loss: Prior service cost (2) 1 — — 1 — 1 Actuarial losses (2) 8 — — 6 — — Tax benefit (expense) (3 ) — (2 ) 6 4 (1 ) Net current period other comprehensive income (loss) 10 (1 ) 5 (25 ) (14 ) — Adoption of ASU 2018-02 — — — (15 ) — (1 ) Ending Balance $ (98 ) $ (15 ) $ 10 $ (108 ) $ (14 ) $ 5 (1) Gains and losses are reclassified from Accumulated other comprehensive income into income when the hedged transactions affect earnings. The reclassification amounts are included in Interest and other finance charges in each of the Registrant’s respective Statements of Consolidated Income. Amounts are $1 million and less than $1 million for the years ended December 31, 2019 and 2018 , respectively. (2) Amounts are included in the computation of net periodic cost and are reflected in Other, net in each of the Registrants’ respective Statements of Consolidated Income.

Short Term Borrowings and Lon_2

Short Term Borrowings and Long Term Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Short-term Borrowings and Long-term Debt [Table Text Block]	December 31, December 31, Long-Term Current (1) Long-Term Current (1) (in millions) CenterPoint Energy: ZENS due 2029 (2) $ — $ 19 $ — $ 24 Senior notes 2.50% to 7.08% due 2020 to 2049 (3) 3,728 100 2,000 — Variable rate term loans 2.275% to 2.56% due 2020 to 2021 1,000 500 — — First mortgage bonds 2.19% to 6.72% due 2022 to 2055 (4) 293 — — — Pollution control bonds 5.125% due 2028 (5) 68 — 68 — Commercial paper (6) (7) 1,901 — — — Unamortized debt issuance costs (22 ) — (13 ) — Unamortized discount and premium, net (7 ) — (2 ) — Houston Electric debt (see details below) 4,719 231 4,258 458 CERC debt (see details below) 2,546 — 2,371 — Other debt 18 18 — — Total CenterPoint Energy debt $ 14,244 $ 868 $ 8,682 $ 482 December 31, December 31, Long-Term Current (1) Long-Term Current (1) (in millions) Houston Electric: First mortgage bonds 9.15% due 2021 $ 102 $ — $ 102 $ — General mortgage bonds 1.85% to 6.95% due 2021 to 2049 3,912 — 3,212 — Restoration Bond Company: System restoration bonds 4.243% due 2022 134 62 197 59 Bond Company II: Transition bonds 5.302% due 2019 — — — 208 Bond Company III: Transition bonds 5.234% due 2020 — 29 29 56 Bond Company IV: Transition bonds 2.161% to 3.028% due 2020 to 2024 613 140 753 135 Unamortized debt issuance costs (27 ) — (24 ) — Unamortized discount and premium, net (15 ) — (11 ) — Total Houston Electric debt $ 4,719 $ 231 $ 4,258 $ 458 December 31, December 31, Long-Term Current (1) Long-Term Current (1) (in millions) CERC (8) : Senior notes 3.55% to 6.625% due 2021 to 2047 $ 2,193 $ — $ 2,193 $ — Commercial paper (6) 377 — 210 — Unamortized debt issuance costs (13 ) — (15 ) — Unamortized discount and premium, net (11 ) — (17 ) — Total CERC debt $ 2,546 $ — $ 2,371 $ — (1) Includes amounts due or exchangeable within one year of the date noted. (2) CenterPoint Energy’s ZENS obligation is bifurcated into a debt component and an embedded derivative component. For additional information regarding ZENS, see Note 12(b). As ZENS are exchangeable for cash at any time at the option of the holders, these notes are classified as a current portion of long-term debt. (3) Includes $532 million of senior notes issued by VUHI and $96 million of senior notes issued by Indiana Gas. The senior notes have stated interest rates that range from 3.72% to 7.08% . The senior notes issued by VUHI are guaranteed by SIGECO, Indiana Gas and VEDO. In connection with the Merger, two of CenterPoint Energy’s acquired wholly-owned subsidiaries, VUHI and VCC, made offers to prepay certain outstanding guaranteed senior notes as required pursuant to certain note purchase agreements previously entered into by VUHI and VCC. In turn, VUHI and VCC borrowed $568 million and $191 million , respectively, from CenterPoint Energy to fund note redemptions of senior notes effected pursuant to these prepayment offers. To fund these prepayments and payments of approximately $5 million of accrued interest, CenterPoint Energy issued approximately $764 million of commercial paper. (4) The first mortgage bonds issued by SIGECO subject SIGECO’s properties to a lien under the related mortgage indenture. (5) $68 million and $68 million of these series of debt were secured by general mortgage bonds of Houston Electric as of December 31, 2019 and 2018 , respectively. These general mortgage bonds are not reflected in Houston Electric’s consolidated financial statements because of the contingent nature of the obligations. (6) Classified as long-term debt because the termination date of the facility that backstops the commercial paper is more than one year from the date noted. (7) Commercial paper issued by VUHI has maturities up to 30 days. (8) Issued by CERC Corp. Long-term Debt Debt Retirements. During the year ended December 31, 2019, CenterPoint Energy retired the following debt instruments: Retirement Date Debt Instrument Aggregate Principal Amount Interest Rate Maturity Date (in millions) CenterPoint Energy December 2019 Guaranteed senior notes $ 3 3.33% 2022 CenterPoint Energy December 2019 Guaranteed senior notes 6 4.53% 2025 In December 2019, VCC redeemed the aggregate principal amount of its guaranteed senior notes at a redemption price equal to 100% of the principal amount thereof, plus accrued and unpaid interest thereon to but excluding the redemption date, plus the make-whole premium. The make-whole premium associated with the two redemptions was approximately $1 million and was included in Other Income, net on CenterPoint Energy’s Statements of Consolidated Income. Debt Transactions. During the year ended December 31, 2019 , the following debt instruments were issued or incurred: Issuance Date Debt Instrument Aggregate Principal Amount Interest Rate as of December 31, 2019 Maturity Date (in millions) Houston Electric January 2019 General mortgage bonds $ 700 4.25% 2049 CenterPoint Energy (1) February 2019 Variable rate term loan 25 2.275% 2020 CenterPoint Energy May 2019 Variable rate term loan 1,000 2.56% 2021 CenterPoint Energy August 2019 Unsecured senior notes 500 2.50% 2024 CenterPoint Energy August 2019 Unsecured senior notes 400 2.95% 2030 CenterPoint Energy August 2019 Unsecured senior notes 300 3.70% 2049 (1) Draw down by VCC on its variable rate term loan.
Schedule of Revolving Credit Facilities and Utilization of Such Facilities [Table Text Block]	The Registrants had the following revolving credit facilities as of December 31, 2019 : Execution Date Registrant Size of Facility Draw Rate of LIBOR plus (1) Financial Covenant Limit on Debt for Borrowed Money to Capital Ratio Debt for Borrowed Money to Capital Ratio as of December 31, 2019 (2) Termination Date (in millions) March 3, 2016 CenterPoint Energy $ 3,300 1.500% 65% (3) 59.0% March 3, 2022 July 14, 2017 CenterPoint Energy (4) 400 1.125% 65% 51.6% July 14, 2022 July 14, 2017 CenterPoint Energy (5) 200 1.250% 65% 58.0% July 14, 2022 March 3, 2016 Houston Electric 300 1.125% 65% (3) 50.2% March 3, 2022 March 3, 2016 CERC 900 1.250% 65% 46.4% March 3, 2022 Total $ 5,100 (1) Based on credit ratings as of December 31, 2019 . (2) As defined in the revolving credit facility agreement, excluding Securitization Bonds. (3) For CenterPoint Energy and Houston Electric, the financial covenant limit will temporarily increase from 65% to 70% if Houston Electric experiences damage from a natural disaster in its service territory and CenterPoint Energy certifies to the administrative agent that Houston Electric has incurred system restoration costs reasonably likely to exceed $100 million in a consecutive 12 -month period, all or part of which Houston Electric intends to seek to recover through securitization financing. Such temporary increase in the financial covenant would be in effect from the date CenterPoint Energy delivers its certification until the earliest to occur of (i) the completion of the securitization financing, (ii) the first anniversary of CenterPoint Energy’s certification or (iii) the revocation of such certification. (4) This credit facility was issued by VUHI, is guaranteed by SIGECO, Indiana Gas and VEDO and includes a $10 million swing line sublimit and a $20 million letter of credit sublimit. This credit facility backstops VUHI’s commercial paper program. (5) This credit facility was issued by VCC, is guaranteed by Vectren and includes a $40 million swing line sublimit and an $80 million letter of credit sublimit. The Registrants, as well as the subsidiaries of CenterPoint Energy discussed above, were in compliance with all financial debt covenants as of December 31, 2019 . As of December 31, 2019 and 2018 , the Registrants had the following revolving credit facilities and utilization of such facilities: December 31, 2019 December 31, 2018 Registrant Loans Letters Commercial Weighted Average Interest Rate Loans Letters Commercial Weighted Average Interest Rate (in millions, except weighted average interest rate) CenterPoint Energy (1) $ — $ 6 $ 1,633 1.95 % $ — $ 6 $ — — % CenterPoint Energy (2) — — 268 2.08 % — — — — % CenterPoint Energy (3) — — — — % — — — — % Houston Electric — — — — % — 4 — — % CERC — 1 377 1.94 % — 1 210 2.93 % Total $ — $ 7 $ 2,278 $ — $ 11 $ 210 (1) CenterPoint Energy’s outstanding commercial paper generally has maturities of 60 days or less. (2) This credit facility was issued by VUHI and is guaranteed by SIGECO, Indiana Gas and VEDO. (3) This credit facility was issued by VCC and is guaranteed by Vectren. In January 2019, CenterPoint Energy issued the following commercial paper in connection with the closing of the Merger: Registrant Issuance Date Debt Instrument Aggregate Principal Amount Weighted Average Interest Rate (in millions) CenterPoint Energy (1) (2) January 2019 Commercial paper $ 1,660 2.88% (1) Proceeds from these commercial paper issuances were used to fund a portion of the Merger and to pay related fees and expenses and were contributed to Vectren for its payment of its stub period cash dividend, long-term incentive payments and to fund the repayment of indebtedness of Vectren subsidiaries redeemed at the option of the holder as a result of the closing of the Merger. (2) The commercial paper notes were issued at various times in January 2019 with maturities up to and including 90 days as of the time of issuance, and, prior to their use as described in connection with the closing of the Merger, the net proceeds of such issuances were invested in short-term investments.
Schedule of Maturities of Long-term Debt [Table Text Block]	Maturities. As of December 31, 2019 , maturities of long-term debt, capital leases and sinking fund requirements, excluding the ZENS obligation, are as follows: CenterPoint Energy (1) Houston Electric (1) CERC Securitization Bonds (in millions) 2020 $ 831 $ 231 $ — $ 231 2021 2,761 613 593 211 2022 3,302 519 376 219 2023 713 356 300 156 2024 1,184 162 — 162 (1) These maturities include Securitization Bonds principal repayments on scheduled payment dates.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Summary of Income Tax Contingencies [Table Text Block]	A reconciliation of CenterPoint Energy’s beginning and ending balance of unrecognized tax benefits, excluding interest and penalties, for 2019 is as follows: Year Ended December 31, 2019 (in millions) Balance, beginning of year $ — Unrecognized tax benefits assumed through the Merger 9 Decreases related to tax positions of prior years (1 ) Balance, end of year $ 8 CenterPoint Energy had no unrecognized tax benefits for 2018 and 2017.
Income Tax Expense [Table Text Block]	The components of the Registrant’ income tax expense (benefit) were as follows: Year Ended December 31, 2019 2018 2017 (in millions) CenterPoint Energy Current income tax expense: Federal $ 48 $ 89 $ 32 State 21 9 9 Total current expense 69 98 41 Deferred income tax expense (benefit): Federal 74 (25 ) (806 ) State (5 ) 73 36 Total deferred expense (benefit) 69 48 (770 ) Total income tax expense (benefit) $ 138 $ 146 $ (729 ) Houston Electric Current income tax expense: Federal $ 84 $ 109 $ 70 State 20 18 19 Total current expense 104 127 89 Deferred income tax benefit: Federal (24 ) (38 ) (98 ) Total deferred benefit (24 ) (38 ) (98 ) Total income tax expense (benefit) $ 80 $ 89 $ (9 ) CERC - Continuing Operations Current income tax expense (benefit): Federal $ — $ (9 ) $ (31 ) State 7 — (10 ) Total current expense (benefit) 7 (9 ) (41 ) Deferred income tax expense (benefit): Federal 39 10 (249 ) State (32 ) 21 25 Total deferred expense (benefit) 7 31 (224 ) Total income tax expense (benefit) $ 14 $ 22 $ (265 ) CERC - Discontinued Operations Current income tax expense (benefit): Federal $ — $ 9 $ 31 State — 4 11 Total current expense (benefit) — 13 42 Deferred income tax expense: Federal — 29 56 State — 4 6 Total deferred expense — 33 62 Total income tax expense $ — $ 46 $ 104
Reconciliation of Expected Federal Income Tax Expense to Actual [Table Text Block]	A reconciliation of income tax expense (benefit) using the federal statutory income tax rate to the actual income tax expense and resulting effective income tax rate is as follows: Year Ended December 31, 2019 2018 2017 (in millions) CenterPoint Energy (1) (2) (3) Income before income taxes $ 929 $ 514 $ 1,063 Federal statutory income tax rate 21 % 21 % 35 % Expected federal income tax expense 195 108 372 Increase (decrease) in tax expense resulting from: State income tax expense, net of federal income tax 36 22 26 State valuation allowance, net of federal income tax (4 ) 11 3 State law change, net of federal income tax (21 ) 32 — Federal income tax rate reduction — — (1,113 ) Excess deferred income tax amortization (55 ) (24 ) — Other, net (13 ) (3 ) (17 ) Total (57 ) 38 (1,101 ) Total income tax expense (benefit) $ 138 $ 146 $ (729 ) Effective tax rate 15 % 28 % (69 )% Houston Electric (4) (5) (6) Income before income taxes $ 436 $ 425 $ 424 Federal statutory income tax rate 21 % 21 % 35 % Expected federal income tax expense 92 89 148 Increase (decrease) in tax expense resulting from: State income tax expense, net of federal income tax 16 14 12 Federal income tax rate reduction — — (158 ) Excess deferred income tax amortization (21 ) (9 ) — Other, net (7 ) (5 ) (11 ) Total (12 ) — (157 ) Total income tax expense (benefit) $ 80 $ 89 $ (9 ) Effective tax rate 18 % 21 % (2 )% CERC - Continuing Operations (7) (8) (9) Income before income taxes $ 226 $ 92 $ 319 Federal statutory income tax rate 21 % 21 % 35 % Expected federal income tax expense 47 19 112 Increase (decrease) in tax expense resulting from: State income tax expense, net of federal income tax (12 ) 5 6 State law change, net of federal income tax (4 ) — — State valuation allowance, net of federal income tax (4 ) 11 3 Federal income tax rate reduction — — (396 ) Goodwill impairment 8 — — Excess deferred income tax amortization (18 ) (15 ) — Tax basis balance sheet adjustment — — 11 Other, net (3 ) 2 (1 ) Total (33 ) 3 (377 ) Total income tax expense (benefit) $ 14 $ 22 $ (265 ) Effective tax rate 6 % 24 % (83 )% Year Ended December 31, 2019 2018 2017 (in millions) CERC - Discontinued Operations (9) Income before income taxes $ — $ 184 $ 265 Federal statutory income tax rate — % 21 % 35 % Expected federal income tax expense — 39 93 Increase in tax expense resulting from: State income tax expense, net of federal income tax — 7 11 Total — 7 11 Total income tax expense $ — $ 46 $ 104 Effective tax rate — % 25 % 39 % (1) Recognized a $55 million benefit for the amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions, a $21 million net benefit for the impact of state law changes that resulted in the remeasurement of state deferred taxes in those jurisdictions, and $4 million net benefit for the reduction in valuation allowances on certain state net operating losses that are now expected to be realized. (2) Recognized a $32 million deferred tax expense due to state law changes that resulted in remeasurement of state deferred taxes in those jurisdictions. Also recorded an additional $11 million valuation allowance on certain state net operating loss deferred tax assets that are no longer expected to be utilized prior to expiration after the Internal Spin. These items are partially offset by $24 million of amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions beginning in 2018. (3) Recognized a $1.1 billion deferred tax benefit from the remeasurement of CenterPoint Energy’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% . (4) Recognized $21 million of amortization of the net regulatory EDIT liability as decreed by regulators. (5) Recognized $9 million of amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions beginning in 2018. (6) Recognized a $158 million deferred tax benefit from the remeasurement of Houston Electric’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% . (7) Recognized $18 million benefit for the amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions, $4 million net benefit for the impact of state law changes that resulted in the remeasurement of state deferred taxes in those jurisdictions and $4 million net benefit for the reduction in valuation allowances on certain state net operating losses that are now expected to be realized. (8) Recorded an additional $11 million valuation allowance on certain state net operating loss deferred tax assets that are no longer expected to be utilized prior to expiration after the Internal Spin. This item is partially offset by $15 million of amortization of the net regulatory EDIT liability in certain jurisdictions as decreed by regulators beginning in 2018. (9) Recognized a $396 million deferred tax benefit from the remeasurement of CERC’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% . ASC 740 requires tax impacts of changes in tax laws or rates be reported in continuing operations. Therefore, CERC’s federal income tax benefit generated by the remeasurement of the ADFIT liability for Enable during 2017 and state law changes during 2016 associated with its investment in Enable are reported in continuing operations on CERC’s Statements of Consolidated Income. The ADFIT liability associated with CERC’s investment in Enable is reported as discontinued operations on CERC’s Consolidated Balance Sheets.
Tax Assets and Liabilities [Table Text Block]	The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities were as follows: December 31, 2019 2018 (in millions) CenterPoint Energy Deferred tax assets: Benefits and compensation $ 152 $ 160 Regulatory liabilities 447 356 Loss and credit carryforwards 111 84 Asset retirement obligations 89 62 Indexed debt securities derivative 34 — Other 40 29 Valuation allowance (25 ) (18 ) Total deferred tax assets 848 673 Deferred tax liabilities: Property, plant and equipment 2,656 1,894 Investment in unconsolidated affiliates 1,010 987 Regulatory assets 344 395 Investment in marketable securities and indexed debt 586 478 Indexed debt securities derivative — 27 Other 180 131 Total deferred tax liabilities 4,776 3,912 Net deferred tax liabilities $ 3,928 $ 3,239 Houston Electric Deferred tax assets: Regulatory liabilities $ 195 $ 205 Benefits and compensation 14 17 Asset retirement obligations 9 7 Other 7 12 Total deferred tax assets 225 241 Deferred tax liabilities: Property, plant and equipment 1,129 1,087 Regulatory assets 126 177 Total deferred tax liabilities 1,255 1,264 Net deferred tax liabilities $ 1,030 $ 1,023 CERC - Continuing Operations Deferred tax assets: Benefits and compensation $ 24 $ 27 Regulatory liabilities 144 150 Loss and credit carryforwards 183 259 Asset retirement obligations 80 54 Other 23 20 Valuation allowance (15 ) (18 ) Total deferred tax assets 439 492 Deferred tax liabilities: Property, plant and equipment 821 773 Regulatory assets 45 41 Other 43 84 Total deferred tax liabilities 909 898 Net deferred tax liabilities $ 470 $ 406

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Long-term Purchase Commitment [Table Text Block]	As of December 31, 2019 , minimum purchase obligations are approximately: CenterPoint Energy CERC (in millions) 2020 $ 750 $ 533 2021 617 432 2022 418 242 2023 335 182 2024 271 174 2025 and beyond 1,888 1,526
Schedule of Environmental Loss Contingencies by Site [Table Text Block]	Total costs that may be incurred in connection with addressing these sites cannot be determined at this time. The estimated accrued costs are limited to CenterPoint Energy’s and CERC’s share of the remediation efforts and are therefore net of exposures of other PRPs. The estimated range of possible remediation costs for the sites for which CenterPoint Energy and CERC believe they may have responsibility was based on remediation continuing for the minimum time frame given in the table below. December 31, 2019 CenterPoint Energy CERC (in millions, except years) Amount accrued for remediation $ 12 $ 7 Minimum estimated remediation costs 7 4 Maximum estimated remediation costs 51 32 Minimum years of remediation 5 30 Maximum years of remediation 50 50

Earnings Per Share (CenterPoi_2

Earnings Per Share (CenterPoint Energy) (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Share [Table Text Block]	The following table reconciles numerators and denominators of CenterPoint Energy’s basic and diluted earnings per common share. Basic earnings per common share is determined by dividing Income available to common shareholders - basic by the Weighted average common shares outstanding - basic for the applicable period. Diluted earnings per common share is determined by the inclusion of potentially dilutive common stock equivalent shares that may occur if securities to issue Common Stock were exercised or converted into Common Stock. For the Year Ended December 31, 2019 2018 2017 (in millions, except per share and share amounts) Numerator: Income available to common shareholders - basic (1) $ 674 $ 333 $ 1,792 Add back: Series B Preferred Stock dividend (2) — — — Income available to common shareholders - diluted (1) $ 674 $ 333 $ 1,792 Denominator: Weighted average common shares outstanding - basic 502,050,000 448,829,000 430,964,000 Plus: Incremental shares from assumed conversions: Restricted stock (3) 3,107,000 3,636,000 3,344,000 Series B Preferred Stock (2) — — — Weighted average common shares outstanding - diluted 505,157,000 452,465,000 434,308,000 Earnings per common share: Basic earnings per common share $ 1.34 $ 0.74 $ 4.16 Diluted earnings per common share $ 1.33 $ 0.74 $ 4.13 (1) Income available to common shareholders for the year ended December 31, 2019 includes net income from businesses acquired in the Merger of $190 million . See Note 4. Income available to common shareholders for the year ended December 31, 2017 includes a reduction in income tax expense of $1,113 million due to tax reform. See Note 15 for further discussion of the impacts of the TCJA. (2) The potentially dilutive impact from Series B Preferred Stock applies the if-converted method in calculating diluted earnings per common share. Under this method, diluted earnings per common share is adjusted for the more dilutive effect of the Series B Preferred Stock as a result of either its accumulated dividend for the period in the numerator or the assumed-converted common share equivalent in the denominator. The computation of diluted earnings per common share outstanding for the year ended December 31, 2019 and December 31, 2018 excludes Series B Stock Dividends of $ 68 million and $17 million , respectively, and 34,354,000 and 8,885,000 potentially dilutive shares, respectively, because to include them would be anti-dilutive. However, these shares could be potentially dilutive in the future. (3) The potentially dilutive impact from restricted stock awards applies the treasury stock method. Under this method, an increase in the average fair market value of Common Stock can result in a greater dilutive impact from these securities.

Unaudited Quarterly Informati_2

Unaudited Quarterly Information (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data [Table Text Block]	Summarized quarterly financial data is as follows: Year Ended December 31, 2019 First Quarter Second Quarter Third Quarter Fourth Quarter (in millions, except per share amounts) CenterPoint Energy Revenues $ 3,531 $ 2,798 $ 2,742 $ 3,230 Operating income 245 287 392 302 Income available to common shareholders 140 165 241 128 Basic earnings per common share (1) 0.28 0.33 0.48 0.25 Diluted earnings per common share (1) 0.28 0.33 0.47 0.25 Houston Electric Revenues 686 765 859 680 Operating income 81 169 269 99 Net income 27 100 185 44 CERC Revenues 2,368 1,342 1,126 1,734 Operating income 196 58 23 73 Net income (loss) 138 28 (7 ) 53 Year Ended December 31, 2018 First Quarter Second Third Quarter Fourth Quarter (in millions, except per share amounts) CenterPoint Energy Revenues $ 3,155 $ 2,186 $ 2,212 $ 3,036 Operating income 251 187 226 167 Income (loss) available to common shareholders 165 (75 ) 153 90 Basic earnings (loss) per common share (1) 0.38 (0.17 ) 0.35 0.18 Diluted earnings (loss) per common share (1) 0.38 (0.17 ) 0.35 0.18 Houston Electric Revenues 755 854 897 728 Operating income 119 181 227 98 Net income 52 101 143 40 CERC (2) Revenues 2,400 1,328 1,312 2,303 Operating income (loss) 131 22 (7 ) 76 Income (loss) from continuing operations 78 (8 ) (35 ) 35 Income (loss) from discontinued operations 52 44 44 (2 ) Net income 130 36 9 33 (1) Quarterly earnings (loss) per common share are based on the weighted average number of shares outstanding during the quarter, and the sum of the quarters may not equal annual earnings (loss) per common share. (2) Amounts have been recast to reflect discontinued operations in all periods presented.

Reportable Segments (Tables)

Reportable Segments (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Financial Data for Business Segments [Table Text Block]	Financial data for reportable segments and products and services are as follows: CenterPoint Energy Revenues from External Customers Net Intersegment Revenues Depreciation and Amortization Operating Income (Loss) Total Assets Expenditures for Long-Lived Assets (in millions) As of and for the year ended December 31, 2019: Houston Electric T&D $ 2,996 (1) $ — $ 648 $ 624 $ 11,264 $ 1,033 Indiana Electric Integrated 523 — 91 90 3,168 183 Natural Gas Distribution 3,643 40 417 408 13,903 1,098 Energy Services 3,653 129 16 32 1,301 12 Infrastructure Services 1,186 (2) 4 50 95 1,077 67 Midstream Investments (3) — — — — 2,473 — Corporate and Other 300 — 65 (23 ) 4,784 (4) 194 Eliminations — (173 ) — — (2,531 ) — Consolidated $ 12,301 $ — $ 1,287 $ 1,226 $ 35,439 $ 2,587 Reconciling items (81 ) Capital expenditures per Statements of Consolidated Cash Flows $ 2,506 As of and for the year ended December 31, 2018: Houston Electric T&D $ 3,232 (1) $ — $ 917 $ 623 $ 10,509 $ 952 Natural Gas Distribution 2,931 36 277 266 6,956 638 Energy Services 4,411 110 16 (47 ) 1,558 20 Midstream Investments (3) — — — — 2,482 — Corporate and Other 15 — 33 (11 ) 6,156 (4) 110 Eliminations — (146 ) — — (652 ) — Consolidated $ 10,589 $ — $ 1,243 $ 831 $ 27,009 $ 1,720 Reconciling items (69 ) Capital expenditures per Statements of Consolidated Cash Flows $ 1,651 As of and for the year ended December 31, 2017: Houston Electric T&D $ 2,997 (1) $ — $ 724 $ 636 $ 10,292 $ 924 Natural Gas Distribution 2,606 33 260 348 6,608 523 Energy Services 3,997 52 19 126 1,521 11 Midstream Investments (3) — — — — 2,472 — Corporate and Other 14 — 33 26 2,497 (4) 36 Eliminations — (85 ) — — (654 ) — Consolidated $ 9,614 $ — $ 1,036 $ 1,136 $ 22,736 $ 1,494 Reconciling items (68 ) Capital expenditures per Statements of Consolidated Cash Flows $ 1,426 (1) CenterPoint Energy’s Houston Electric T&D’s revenues from major customers are as follows: Year Ended December 31, 2019 2018 2017 (in millions) Affiliates of NRG $ 727 $ 705 $ 713 Affiliates of Vistra Energy Corp. 263 251 229 (2) Includes revenues not eliminated in consolidation for pipeline construction and repair services of $162 million capitalized by CenterPoint Energy’s NGD for the 11 months ended December 31, 2019. See Note 2(b). (3) CenterPoint Energy’s Midstream Investments’ equity earnings, net are as follows: Year Ended December 31, 2019 2018 2016 (in millions) Enable $ 229 $ 307 $ 265 (4) Total assets included pension and other postemployment-related regulatory assets of $584 million , $665 million and $600 million as of December 31, 2019 , 2018 and 2017 , respectively. Additionally, total assets as of December 31, 2018 included $3.9 billion of temporary investments included in Cash and cash equivalents on CenterPoint Energy’s Consolidated Balance Sheets. Houston Electric Houston Electric consists of a single reportable segment; therefore, a tabular reportable segment presentation has not been included. (1) Houston Electric’s revenues from major external customers are as follows: Year Ended December 31, 2019 2018 2017 (in millions) Affiliates of NRG $ 727 $ 705 $ 713 Affiliates of Vistra Energy Corp. 263 251 229 CERC Revenues from External Customers Net Intersegment Revenues Depreciation and Amortization Operating Income (Loss) Total Assets (1) Expenditures for Long-Lived Assets (in millions) As of and for the year ended December 31, 2019: Natural Gas Distribution $ 2,911 $ 40 $ 289 $ 316 $ 7,497 $ 773 Energy Services 3,654 128 16 32 1,301 12 Other Operations 5 — — 2 149 — Eliminations — (168 ) — — (508 ) — Consolidated $ 6,570 $ — $ 305 $ 350 $ 8,439 $ 785 Reconciling items (9 ) Capital expenditures per Statements of Consolidated Cash Flows $ 776 As of and for the year ended December 31, 2018: Natural Gas Distribution $ 2,931 $ 36 $ 277 $ 266 $ 6,956 $ 638 Energy Services 4,411 110 16 (47 ) 1,558 20 Other Operations 1 — — 3 66 — Eliminations — (146 ) — — (366 ) — Consolidated $ 7,343 $ — $ 293 $ 222 $ 8,214 $ 658 Reconciling items (25 ) Capital expenditures per Statements of Consolidated Cash Flows $ 633 Revenues from External Customers Net Intersegment Revenues Depreciation and Amortization Operating Income (Loss) Total Assets (1) Expenditures for Long-Lived Assets (in millions) As of and for the year ended December 31, 2017: Natural Gas Distribution $ 2,606 $ 33 $ 260 $ 348 $ 6,608 $ 523 Energy Services 3,997 52 19 126 1,521 11 Discontinued operations — — — — 2,472 (1) — Other Operations — — — (7 ) 70 — Eliminations — (85 ) — — (559 ) — Consolidated $ 6,603 $ — $ 279 $ 467 $ 10,112 $ 534 Reconciling items (21 ) Capital expenditures per Statements of Consolidated Cash Flows $ 513 (1) On September 4, 2018, CERC completed the Internal Spin. For further information regarding the Internal Spin, see Note 11 .
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]	CenterPoint Energy’s Houston Electric T&D’s revenues from major customers are as follows: Year Ended December 31, 2019 2018 2017 (in millions) Affiliates of NRG $ 727 $ 705 $ 713 Affiliates of Vistra Energy Corp. 263 251 229
Midstream Investments [Table Text Block]	CenterPoint Energy’s Midstream Investments’ equity earnings, net are as follows: Year Ended December 31, 2019 2018 2016 (in millions) Enable $ 229 $ 307 $ 265
Revenues by Products and Services [Table Text Block]	Year Ended December 31, 2019 2018 2017 Revenues by Products and Services: CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Electric delivery $ 3,019 $ 2,990 $ — $ 3,232 $ 3,234 $ — $ 2,997 $ 2,998 $ — Retail electric sales 486 — — — — — — — — Wholesale electric sales 14 — — — — — — — — Retail gas sales 4,802 — 4,070 4,161 — 4,161 3,634 — 3,634 Wholesale gas sales 2,312 — 2,313 3,008 — 3,008 2,811 — 2,811 Gas transportation and processing 33 — 33 32 — 32 29 — 29 Infrastructure services 1,186 — — — — — — — — Energy products and services 449 — 154 156 — 142 143 — 129 Total $ 12,301 $ 2,990 $ 6,570 $ 10,589 $ 3,234 $ 7,343 $ 9,614 $ 2,998 $ 6,603

Supplemental Disclosure of Ca_2

Supplemental Disclosure of Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The tables below provide supplemental disclosure of cash flow information: 2019 2018 2017 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Cash Payments/Receipts: Interest, net of capitalized interest $ 436 $ 229 $ 109 $ 363 $ 200 $ 105 $ 378 $ 205 $ 116 Income taxes (refunds), net 155 87 7 89 154 3 15 76 4 Non-cash transactions: Accounts payable related to capital expenditures 236 117 86 201 124 80 144 104 56 Capital distribution associated with the Internal Spin (1) — — 28 — — 1,473 — — — ROU assets obtained in exchange for lease liabilities (2) 44 1 29 — — — — — — (1) The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018. (2) Includes the transition impact of adoption of ASU 2016-02 Leases as of January 1, 2019. The Registrants elected not to recast comparative periods in the year of adoption as permitted by the standard. The table below provides a reconciliation of cash, cash equivalents and restricted cash reported in the Consolidated Balance Sheets to the amount reported in the Statements of Consolidated Cash Flows: December 31, 2019 December 31, 2018 CenterPoint Energy Houston Electric CERC CenterPoint Energy Houston Electric CERC (in millions) Cash and cash equivalents (1) (2) $ 241 $ 216 $ 2 $ 4,231 $ 335 $ 14 Restricted cash included in Prepaid expenses and other current assets 30 19 — 46 34 11 Restricted cash included in Other — — — 1 1 — Total cash, cash equivalents and restricted cash shown in Statements of Consolidated Cash Flows $ 271 $ 235 $ 2 $ 4,278 $ 370 $ 25 (1) CenterPoint Energy’s Cash and cash equivalents as of December 31, 2018 included $3.9 billion of temporary investments resulting from the Merger financings. CenterPoint Energy recorded interest income of $22 million , $28 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on CenterPoint Energy’s Statements of Consolidated Income. See Notes 13 and 14 for further details related to the Merger financings. (2) Houston Electric’s Cash and cash equivalents as of December 31, 2019 and 2018 included $216 million and $335 million , respectively, of cash related to the Bond Companies. Houston Electric recorded interest income of $9 million , $4 million and $2 million for the years ended December 31, 2019 , 2018 and 2017

Related Party Transactions (H_2

Related Party Transactions (Houston Electric and CERC) (Tables)	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Schedule of Money Pool Investment and Borrowing [Table Text Block]	Houston Electric and CERC participate in a money pool through which they can borrow or invest on a short-term basis. Funding needs are aggregated and external borrowing or investing is based on the net cash position. The net funding requirements of the money pool are expected to be met with borrowings under CenterPoint Energy’s revolving credit facility or the sale of CenterPoint Energy’s commercial paper. The table below summarizes money pool activity: December 31, 2019 December 31, 2018 Houston Electric CERC Houston Electric CERC (in millions) Money pool investments (borrowings) (1) $ 481 $ — $ (1 ) $ 114 Weighted average interest rate 1.98 % 1.98 % 2.42 % 2.42 % (1) Included in Accounts and notes receivable (payable)–affiliated companies in Houston Electric’s and CERC’s Consolidated Balance Sheets.
Schedule of Related Party Transactions [Table Text Block]	Houston Electric and CERC affiliate-related net interest income (expense) were as follows: Year Ended December 31, 2019 2018 2017 Houston Electric CERC Houston Electric CERC Houston Electric CERC (in millions) Interest income (expense), net (1) $ 18 $ 4 $ 1 $ — $ 2 $ — (1) Interest income is included in Other, net and interest expense is included in Interest and other finance charges on Houston Electric’s and CERC’s respective Statements of Consolidated Income. Amounts charged for these services are included primarily in Operation and maintenance expenses and amounts billed for natural gas sales are included in Non-utility revenues were as follows: Year Ended December 31, 2019 2018 2017 Houston Electric CERC Houston Electric CERC Houston Electric CERC (in millions) Corporate service charges $ 177 $ 141 $ 190 $ 147 $ 188 $ 128 Net affiliate service charges (billings) (8 ) 8 (17 ) 17 (9 ) 9 Pipeline construction and repair service charges (1) — 4 — — — — Natural gas sales (2) — 1 — — — — (1) Represents charges from Infrastructure Services to CERC’s NGD for the period February 1, 2019 through December 31, 2019. (2) Represents sales to Indiana Electric from CES for the period February 1, 2019 through December 31, 2019. The table below presents transactions among Houston Electric, CERC and their parent, Utility Holding. Year Ended December 31, 2019 2018 2017 Houston Electric CERC Houston Electric CERC Houston Electric CERC (in millions) Cash dividends paid to parent $ 376 $ 120 $ 209 $ 360 $ 180 $ 601 Cash contribution from parent 590 129 200 960 — 38 Capital distribution to parent associated with the Internal Spin (1) — 28 — 1,473 — — (1) The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lease, Cost [Table Text Block]	The components of lease cost, included in Operation and maintenance expense on the Registrants’ respective Statements of Consolidated Income, are as follows: Year Ended December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions) Operating lease cost $ 25 $ — $ 5 Short-term lease cost 75 23 — Variable lease cost 1 — 1 Total lease cost $ 101 $ 23 $ 6
Operating Lease, Lease Income [Table Text Block]	The components of lease income were as follows: Year Ended December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions) Operating lease income $ 4 $ 2 $ 1 Variable lease income 2 — — Total lease income $ 6 $ 2 $ 1
Supplemental Balance Sheet Information Related To Leases [Table Text Block]	Supplemental balance sheet information related to leases was as follows: December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions, except lease term and discount rate) Assets: Operating ROU assets (1) $ 63 $ 1 $ 24 Total leased assets $ 63 $ 1 $ 24 Liabilities: Current operating lease liability (2) $ 21 $ — $ 4 Non-current operating lease liability (3) 42 1 20 Total leased liabilities $ 63 $ 1 $ 24 Weighted-average remaining lease term (in years) - operating leases 5.1 5.2 7.7 Weighted-average discount rate - operating leases 3.42 % 3.52 % 3.67 % (1) Reported within Other assets in the Registrants’ respective Consolidated Balance Sheets. (2) Reported within Current other liabilities in the Registrants’ respective Consolidated Balance Sheets. (3) Reported within Other liabilities in the Registrants’ respective Consolidated Balance Sheets.
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	As of December 31, 2019 , maturities of operating lease liabilities were as follows: CenterPoint Energy Houston Electric CERC (in millions) 2020 $ 22 $ 1 $ 6 2021 16 — 4 2022 9 — 4 2023 7 — 3 2024 3 — 2 2025 and beyond 12 — 9 Total lease payments 69 1 28 Less: Interest 6 — 4 Present value of lease liabilities $ 63 $ 1 $ 24
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	The following table sets forth information concerning the Registrants’ obligations under non-cancelable long-term operating leases as of December 31, 2018: CenterPoint Energy Houston Electric CERC (in millions) 2019 $ 6 $ 1 $ 5 2020 6 — 5 2021 5 — 4 2022 4 — 4 2023 3 — 3 2024 and beyond 12 — 11 Total (1) $ 36 $ 1 $ 32 (1)
Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block]	As of December 31, 2019 , maturities of undiscounted operating lease payments to be received are as follows: CenterPoint Energy Houston Electric CERC (in millions) 2020 $ 3 $ 1 $ 1 2021 2 — — 2022 2 — — 2023 2 — — 2024 2 — — 2025 and beyond 10 — — Total lease payments to be received $ 21 $ 1 $ 1
Other Information Related To Leases [Table Text Block]	Other information related to leases is as follows. See Note 20 for information on ROU assets obtained in exchange for operating lease liabilities: Year Ended December 31, 2019 CenterPoint Energy Houston Electric CERC (in millions) Operating cash flows from operating leases included in the measurement of lease liabilities $ 25 $ 1 $ 6

Subsequent Events (Tables)

Subsequent Events (Tables)	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Schedule of Subsequent Events [Table Text Block]	CenterPoint Energy Dividend Declarations (CenterPoint Energy) Equity Instrument Declaration Date Record Date Payment Date Per Share Common Stock February 3, 2020 February 20, 2020 March 12, 2020 $ 0.2900 Series A Preferred Stock February 3, 2020 February 14, 2020 March 2, 2020 30.6250 Series B Preferred Stock February 3, 2020 February 14, 2020 March 2, 2020 17.5000 Enable Distributions Declarations (CenterPoint Energy) Equity Instrument Declaration Date Record Date Payment Date Per Unit Distribution Expected Cash Distribution (in millions) Enable common units February 7, 2020 February 18, 2020 February 25, 2020 $ 0.3305 $ 77 Enable Series A Preferred Units February 7, 2020 February 7, 2020 February 14, 2020 0.6250 9

Background (Details)

Background (Details) $ in Millions		Feb. 03, 2020USD ($)	Feb. 01, 2019USD ($)	Dec. 31, 2019USD ($)stateshares	Dec. 31, 2018
Vectren [Member]
Cash paid to acquire Vectren | $			$ 6,000	$ 5,982
Enable Midstream Partners [Member]
Ownership percentage of equity method investment	[1],[2]			53.70%	54.00%
Enable Midstream Partners [Member] | Series A Preferred Units [Member]
Preferred units held | shares				14,520,000
Enable GP, LLC [Member]
Management rights ownership percentage				50.00%
Incentive distribution right				40.00%
CERC Corp [Member] | Natural Gas Distribution [Member]
Number of states in which entity operates | state				6
CERC Corp [Member] | Energy Services [Member]
Number of states in which entity operates | state				30
CenterPoint Energy [Member] | Enable GP, LLC [Member]
Management rights ownership percentage	[3],[4]			50.00%
Incentive distribution right	[4],[5]			40.00%
Subsequent Event [Member] | Infrastructure Services [Member]
Sales price of outstanding equity interests | $		$ 850
[1]	Excludes the Enable Series A Preferred Units owned by CenterPoint Energy.
[2]	Prior to the Internal Spin completed in September 2018, CenterPoint Energy’s investment in Enable’s common units, excluding the Enable Series A Preferred Units held directly by CenterPoint Energy, was held indirectly through CERC.
[3]	As of December 31, 2019 , Enable is controlled jointly by CenterPoint Energy and OGE. Sale of CenterPoint Energy’s or OGE’s ownership interests in Enable GP to a third party is subject to mutual rights of first offer and first refusal, and CenterPoint Energy is not permitted to dispose of less than all of its interest in Enable GP.
[4]	Held indirectly through CNP Midstream.
[5]	Enable is expected to pay a minimum quarterly distribution of $0.2875 per common unit on its outstanding common units to the extent it has sufficient cash from operations after establishment of cash reserves and payment of fees and expenses, including payments to Enable GP and its affiliates, within 60 days after the end of each quarter. If cash distributions to Enable’s unitholders exceed $0.330625 per common unit in any quarter, Enable GP will receive increasing percentages or incentive distributions rights, up to 50% , of the cash Enable distributes in excess of that amount. In certain circumstances Enable GP will have the right to reset the minimum quarterly distribution and the target distribution levels at which the incentive distributions receive increasing percentages to higher levels based on Enable’s cash distributions at the time of the exercise of this reset election. To date, no incentive distributions have been made.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Capitalized Fees Not Eliminated in Consolidation		$ 162
Provision for doubtful accounts		16	$ 16	$ 14
Interest Expense [Member]
Significant Accounting Policies [Line Items]
Interest and AFUDC debt (1)	[1]	36	8	9
Other Income (Expense) [Member]
Significant Accounting Policies [Line Items]
AFUDC equity (2)	[2]	22	12	11
Houston Electric [Member]
Significant Accounting Policies [Line Items]
Provision for doubtful accounts		0	0	1
Houston Electric [Member] | Interest Expense [Member]
Significant Accounting Policies [Line Items]
Interest and AFUDC debt (1)	[1]	8	6	6
Houston Electric [Member] | Other Income (Expense) [Member]
Significant Accounting Policies [Line Items]
AFUDC equity (2)	[2]	15	10	10
CERC Corp [Member]
Significant Accounting Policies [Line Items]
Capitalized Fees Not Eliminated in Consolidation		20
Provision for doubtful accounts		12	16	13
CERC Corp [Member] | Interest Expense [Member]
Significant Accounting Policies [Line Items]
Interest and AFUDC debt (1)	[1]	3	2	2
CERC Corp [Member] | Other Income (Expense) [Member]
Significant Accounting Policies [Line Items]
AFUDC equity (2)	[2]	$ 3	$ 2	$ 1
[1]	Included in Interest and other finance charges on the Registrants’ respective Statements of Consolidated Income.
[2]	Included in Other Income (Expense) on the Registrants’ respective Statements of Consolidated Income.

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 30,685		$ 20,267
Accumulated Depreciation & Amortization		9,740		6,223
Property, Plant and Equipment, Net		20,945		14,044
Depreciation and Amortization [Abstract]
Depreciation		920		626	$ 619
Amortization of securitized regulatory assets		271		531	329
Other amortization		96		86	88
Total		1,287		1,243	1,036
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance		258		281
Asset Retirement Obligation Addition from Merger with Vectren		116
Accretion expense (1)	[1]	16		10
Revisions in estimates (2)	[2]	149		(33)
Ending balance		539		258	281
Houston Electric [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		12,829		12,148
Accumulated Depreciation & Amortization		3,797		3,746
Property, Plant and Equipment, Net		9,032		8,402
Depreciation and Amortization [Abstract]
Depreciation		339		342	354
Amortization of securitized regulatory assets		271		531	329
Other amortization		38		44	41
Total		648		917	724
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance		34		35
Accretion expense (1)	[1]	1		1
Revisions in estimates (2)	[2]	7		(2)
Ending balance		42		34	35
CERC Corp [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		8,124		7,431
Accumulated Depreciation & Amortization		2,288		2,205
Property, Plant and Equipment, Net		5,836		5,226
Depreciation and Amortization [Abstract]
Depreciation		281		264	243
Other amortization		24		29	36
Total		305		293	279
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance		221		243
Accretion expense (1)	[1]	10		9
Revisions in estimates (2)	[2]	94		(31)
Ending balance		325		221	$ 243
Electric Transmission and Distribution [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		14,360		12,148
Accumulated Depreciation & Amortization		4,634		3,746
Property, Plant and Equipment, Net		$ 9,726		8,402
Electric Transmission and Distribution [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		37 years
Electric Generation Equipment [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 1,780	[3]	0
Accumulated Depreciation & Amortization		698	[3]	0
Property, Plant and Equipment, Net		$ 1,082	[3]	0
Electric Generation Equipment [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		27 years
Electric Transmission [Member] | Houston Electric [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 3,358		3,077
Accumulated Depreciation & Amortization		674		650
Property, Plant and Equipment, Net		$ 2,684		2,427
Electric Transmission [Member] | Houston Electric [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		46 years
Electric Distribution [Member] | Houston Electric [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 7,876		7,524
Accumulated Depreciation & Amortization		2,586		2,553
Property, Plant and Equipment, Net		$ 5,290		4,971
Electric Distribution [Member] | Houston Electric [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		35 years
Natural Gas Distribution [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 12,695		7,257
Accumulated Depreciation & Amortization		3,731		2,128
Property, Plant and Equipment, Net		$ 8,964		5,129
Natural Gas Distribution [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		29 years
Natural Gas Distribution [Member] | CERC Corp [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 7,933		7,257
Accumulated Depreciation & Amortization		2,208		2,128
Property, Plant and Equipment, Net		$ 5,725		5,129
Natural Gas Distribution [Member] | CERC Corp [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		29 years
Energy Services [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 136	[4]	121
Accumulated Depreciation & Amortization		53	[4]	43
Property, Plant and Equipment, Net		$ 83	[4]	78
Energy Services [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		27 years
Energy Services [Member] | CERC Corp [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 136	[4]	121
Accumulated Depreciation & Amortization		53	[4]	43
Property, Plant and Equipment, Net		$ 83	[4]	78
Energy Services [Member] | CERC Corp [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		27 years
Infrastructure Services [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 317	[5]	0
Accumulated Depreciation & Amortization		22	[5]	0
Property, Plant and Equipment, Net		$ 295	[5]	0
Infrastructure Services [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		10 years
Other property [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 1,397		741
Accumulated Depreciation & Amortization		602		306
Property, Plant and Equipment, Net		$ 795		435
Other property [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		19 years
Other property [Member] | Houston Electric [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 1,595		1,547
Accumulated Depreciation & Amortization		537		543
Property, Plant and Equipment, Net		$ 1,058		1,004
Other property [Member] | Houston Electric [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		19 years
Other property [Member] | CERC Corp [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Property, Plant and Equipment, Gross		$ 55		53
Accumulated Depreciation & Amortization		27		34
Property, Plant and Equipment, Net		$ 28		$ 19
Other property [Member] | CERC Corp [Member] | Weighted Average [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
Weighted Average Useful Lives		16 years
SIGECO [Member]
Property, Plant and Equipment, Net, by Type [Abstract]
SIGECO's share of cost of Warrick Unit 4		$ 194
SIGECO's share of accumulated depreciation of Warrick Unit 4		$ 137
[1]	Reflected in Regulatory assets on each of the Registrants’ respective Consolidated Balance Sheets.
[2]	In 2019, the Registrants reflected an increase in their respective ARO liability, which is primarily attributable to decreases in the long-term interest rates used for discounting in the ARO calculation and increased estimated closure costs for CenterPoint Energy’s electric generation. In 2018, CenterPoint Energy and CERC reflected a decrease in their respective ARO liability, which is primarily attributable to increases in the long-term interest rates used for discounting in the ARO calculation.
[3]	SIGECO and AGC own a 300 MW unit at the Warrick Power Plant (Warrick Unit 4) as tenants in common. SIGECO’s share of the cost of this unit as of December 31, 2019, is $194 million with accumulated depreciation totaling $137 million . AGC and SIGECO share equally in the cost of operation and output of the unit. SIGECO’s share of operating costs is included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income.
[4]	On February 24, 2020, CenterPoint Energy, through its subsidiary CERC Corp., entered into the Equity Purchase Agreement to sell CES, which represents substantially all of the businesses within the Energy Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23.
[5]	On February 3, 2020, CenterPoint Energy, through its subsidiary VUSI, entered into the Securities Purchase Agreement to sell the businesses within its Infrastructure Services reportable segment. The transaction is expected to close in the second quarter of 2020. For further information, see Notes 6 and 23.

Mergers and Acquisitions (Detai

Mergers and Acquisitions (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 01, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Dividends declared per share										$ 0.86		$ 1.1200		$ 1.35
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill		$ 5,164				$ 867				$ 5,164		$ 867
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Amortization expense of intangible assets										24		0		$ 0
Business Combination, Separately recognized Transactions, Additional Disclosures [Abstract]
Total revenues		$ 3,230	$ 2,742	$ 2,798	$ 3,531	$ 3,036	$ 2,212	$ 2,186	$ 3,155	12,301		10,589		9,614
Net income										791		368		1,792
Non-utility cost of revenues [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Amortization expense of intangible assets										24	[1]	0		0
Depreciation and amortization expense [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Amortization expense of intangible assets										25	[1],[2]	10		$ 13
Vectren [Member]
Total purchase price consideration	$ 6,000									$ 5,982
Cash paid per share of Vectren common stock at closing of the Merger		$ 72								$ 72
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents		$ 16								$ 16
Other current assets		577								577
Property, plant and equipment, net		5,147								5,147
Identifiable intangibles		297								297
Regulatory assets		338								338
Other assets		141								141
Total assets acquired		6,516								6,516
Current liabilities		648								648
Regulatory liabilities		938								938
Other liabilities		886								886
Long-term debt		2,401								2,401
Total liabilities assumed		4,873								4,873
Net assets acquired		1,643								1,643
Goodwill		4,339								4,339
Total purchase price consideration	$ 6,000									5,982
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Estimated Fair Value										297
Business Combination, Separately recognized Transactions, Additional Disclosures [Abstract]
Total revenues										2,729
Net income										190
Business Acquisition, Pro Forma Information [Abstract]
Operating Revenue										12,547		13,282
Net Income (1)										812	[3]	458	[4]
Vectren [Member] | Operation And Maintenance Expense [Member]
Severance expense related to the Merger					$ 61					102
Business Combination, Separately recognized Transactions, Additional Disclosures [Abstract]
Integration costs										83
Vectren [Member] | Depreciation and amortization expense [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Amortization expense of intangible assets										$ 17
Vectren [Member] | Operation and maintenance agreements [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Weighted Average Useful Lives										24 years
Estimated Fair Value										$ 12
Vectren [Member] | Customer Relationships [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Weighted Average Useful Lives										18 years
Estimated Fair Value										$ 200
Vectren [Member] | Construction backlog [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Weighted Average Useful Lives										1 year
Estimated Fair Value										$ 27
Vectren [Member] | Trade Names [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Weighted Average Useful Lives										10 years
Estimated Fair Value										$ 58
Vectren [Member] | Operation and maintenance agreements and construction backlog [Member] | Non-utility cost of revenues [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Amortization expense of intangible assets										24
Vectren [Member] | Customer relationships and trade names [Member] | Depreciation and amortization expense [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill [Abstract]
Amortization expense of intangible assets										$ 16
Vectren [Member] | Stub period [Member]
Dividends declared per share										$ 0.41145
Vectren acquisition [Member]
Cash payments towards outstanding share-based awards		78								$ 78
Share-based award liability recorded		41								41
Incremental share-based awards expense recorded										37
Utility pipeline construction company [Member]
Total purchase price consideration										25
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Identifiable intangibles		8								8
Goodwill		$ 6								6
Total purchase price consideration										25
Vectren [Member] | Pro Forma [Member] | Vectren acquisition [Member]
Business Acquisition, Pro Forma Information [Abstract]
Transaction costs associated with the Merger										$ 37		$ 37
[1]	The fair value of intangible assets, and related amortization assumptions, acquired through acquisitions during the year ended December 31, 2019 , has been finalized. See Note 4 .
[2]	Includes $17 million for the year ended December 31, 2019 of amortization expense related to intangibles acquired in the Merger.
[3]	Pro forma net income was adjusted to exclude $37 million of Vectren Merger-related transaction costs incurred in 2019.
[4]	Pro forma net income was adjusted to include $37 million of Vectren Merger-related transaction costs incurred in 2019 .

Revenue Recognition Disaggregat

Revenue Recognition Disaggregation of Revenue (Details) - USD ($) $ in Millions		3 Months Ended												12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts														$ 9,151		$ 6,745	$ 6,124
Derivatives income														3,311		4,024	3,568
Other (3)	[1]													12		(34)	7
Total revenues		$ 3,230	$ 2,742	$ 2,798	$ 3,531	$ 3,036		$ 2,212		$ 2,186		$ 3,155		12,301		10,589	9,614
Electric Transmission & Distribution [Member]
Disaggregation of Revenue [Line Items]
Total revenues	[2]													2,996		3,232	2,997
Indiana Electric Integrated [Member]
Disaggregation of Revenue [Line Items]
Total revenues	[2]													523
Natural Gas Distribution [Member]
Disaggregation of Revenue [Line Items]
Total revenues														3,643		2,931	2,606
Energy Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues														3,653		4,411	3,997
Infrastructure Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues	[3]													1,186
Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues														300		15	14
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Total revenues														(173)		(146)	(85)
Intersegment Eliminations [Member] | Electric Transmission & Distribution [Member]
Disaggregation of Revenue [Line Items]
Total revenues														0		0	0
Intersegment Eliminations [Member] | Natural Gas Distribution [Member]
Disaggregation of Revenue [Line Items]
Total revenues														(40)		(36)	(33)
Intersegment Eliminations [Member] | Energy Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues														(129)		(110)	(52)
Intersegment Eliminations [Member] | Infrastructure Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues														(4)
Intersegment Eliminations [Member] | Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues														0		0	0
Reportable Subsegments [Member] | Electric Transmission & Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[4]													2,984		3,235	3,001
Derivatives income	[4]													6		(2)	(1)
Other (3)	[1],[4]													6		(1)	(3)
Total revenues	[4]													2,996		3,232	2,997
Reportable Subsegments [Member] | Indiana Electric Integrated [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[4]													523	[5]	0	0
Derivatives income	[4]													0	[5]	0	0
Other (3)	[1],[4]													0	[5]	0	0
Total revenues	[4]													523	[5]	0	0
Reportable Subsegments [Member] | Natural Gas Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[4]													3,680	[5]	3,011	2,638
Derivatives income	[4]													2	[5]	(2)	0
Other (3)	[1],[4]													1	[5]	(42)	1
Total revenues	[4]													3,643	[5]	2,931	2,606
Reportable Subsegments [Member] | Energy Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[6]													479		493	480
Derivatives income	[6]													3,303		4,028	3,569
Other (3)	[1],[6]															0	0
Total revenues	[6]													3,653		4,411	3,997
Reportable Subsegments [Member] | Infrastructure Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[6]													1,190	[5]	0	0
Derivatives income	[6]															0	0
Other (3)	[1],[6]															0	0
Total revenues	[6]													1,186	[5]	0	0
Reportable Subsegments [Member] | Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[6]													295	[5]	6	5
Derivatives income	[6]															0	0
Other (3)	[1],[6]													5	[5]	9	9
Total revenues	[6]													300	[5]	15	14
Reportable Subsegments [Member] | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[4]													(40)	[5]	(36)	(33)
Derivatives income	[6]													(129)		(110)	(52)
Total revenues														(173)		(146)	(85)
Reportable Subsegments [Member] | Intersegment Eliminations [Member] | Infrastructure Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[6]													(4)	[5]	0	0
Houston Electric [Member]
Disaggregation of Revenue [Line Items]
Total revenues		680	859	765	686	728		897		854		755		2,990		3,234	2,998
Houston Electric [Member] | Reportable Subsegments [Member] | Electric Transmission & Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts														2,984		3,235	3,001
Other (3)	[7]													6		(1)	(3)
Total revenues														2,990		3,234	2,998
CERC Corp [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts														3,430		3,505	3,118
Derivatives income														3,304		4,026	3,569
Other (3)	[8]													4		(42)	1
Total revenues		$ 1,734	$ 1,126	$ 1,342	$ 2,368	$ 2,303	[9]	$ 1,312	[9]	$ 1,328	[9]	$ 2,400	[9]	6,570		7,343	6,603
CERC Corp [Member] | Natural Gas Distribution [Member]
Disaggregation of Revenue [Line Items]
Total revenues														2,911		2,931	2,606
CERC Corp [Member] | Energy Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues														3,654		4,411	3,997
CERC Corp [Member] | Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues														5		1	0
CERC Corp [Member] | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Total revenues														(168)		(146)	(85)
CERC Corp [Member] | Intersegment Eliminations [Member] | Natural Gas Distribution [Member]
Disaggregation of Revenue [Line Items]
Total revenues														(40)		(36)	(33)
CERC Corp [Member] | Intersegment Eliminations [Member] | Energy Services [Member]
Disaggregation of Revenue [Line Items]
Total revenues														(128)		(110)	(52)
CERC Corp [Member] | Intersegment Eliminations [Member] | Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Total revenues														0		0	0
CERC Corp [Member] | Reportable Subsegments [Member] | Natural Gas Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[10]													2,945		3,011	2,638
Derivatives income	[10]													2		(2)	0
Other (3)	[8],[10]													4		(42)	1
Total revenues	[10]													2,911		2,931	2,606
CERC Corp [Member] | Reportable Subsegments [Member] | Energy Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[11]													480		493	480
Derivatives income	[11]													3,302		4,028	3,569
Other (3)	[8],[11]													0		0	0
Total revenues	[11]													3,654		4,411	3,997
CERC Corp [Member] | Reportable Subsegments [Member] | Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[11]													5		1	0
Derivatives income	[11]													0		0	0
Other (3)	[8],[11]													0		0	0
Total revenues	[11]													5		1	0
CERC Corp [Member] | Reportable Subsegments [Member] | Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts	[10]													(40)		(36)	(33)
Derivatives income	[11]													(128)		(110)	(52)
Total revenues														$ (168)		$ (146)	$ (85)
[1]	Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period.
[2]	CenterPoint Energy’s Houston Electric T&D’s revenues from major customers are as follows: Year Ended December 31, 2019 2018 2017 (in millions) Affiliates of NRG $ 727 $ 705 $ 713 Affiliates of Vistra Energy Corp. 263 251 229
[3]	Includes revenues not eliminated in consolidation for pipeline construction and repair services of $162 million capitalized by CenterPoint Energy’s NGD for the 11 months ended December 31, 2019. See Note 2(b).
[4]	Reflected in Utility revenues in the Statements of Consolidated Income.
[5]	Reflects revenues from Vectren subsidiaries for the period from February 1, 2019 to December 31, 2019.
[6]	Reflected in Non-utility revenues in the Statements of Consolidated Income.
[7]	Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period.
[8]	Primarily consists of income from ARPs and leases. ARPs are contracts between the utility and its regulators, not between the utility and a customer. The Registrants recognize ARP revenue as other revenues when the regulator-specified conditions for recognition have been met. Upon recovery of ARP revenue through incorporation in rates charged for utility service to customers, ARP revenue is reversed and recorded as revenue from contracts with customers. The recognition of ARP revenues and the reversal of ARP revenues upon recovery through rates charged for utility service may not occur in the same period.
[9]	Amounts have been recast to reflect discontinued operations in all periods presented.
[10]	Reflected in Utility revenues in the Statements of Consolidated Income.
[11]	Reflected in Non-utility revenues in the Statements of Consolidated Income.

Revenue Recognition Summary of

Revenue Recognition Summary of Contract Assets and Liabilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Change in Accounts Receivable [Roll Forward]
Opening balance as of December 31, 2018 (1)	$ 516	[1]
Closing balance as of December 31, 2019	800
Increase (Decrease) in Accounts Receivable	284
Change in Other Accrued Unbilled Revenues [Roll Forward]
Opening balance as of December 31, 2018 (1)	373	[1]
Closing balance as of December 31, 2019	579
Increase (Decrease) in Other Accrued Unbilled Revenues	206
Change in Contract Asset [Roll Forward]
Opening balance as of December 31, 2018 (1)	0	[1]
Closing balance as of December 31, 2019	61
Increase (Decrease) in Contract with Customer, Asset	61
Change in Contract Liability [Roll Forward]
Opening balance as of December 31, 2018 (1)	3	[1]
Closing balance as of December 31, 2019	34
Increase (Decrease) in Contract with Customer, Liability	31
Contract with Customer, Liability, Revenue Recognized	47
Houston Electric [Member]
Change in Accounts Receivable [Roll Forward]
Opening balance as of December 31, 2018 (1)	234
Closing balance as of December 31, 2019	210
Increase (Decrease) in Accounts Receivable	(24)
Change in Other Accrued Unbilled Revenues [Roll Forward]
Opening balance as of December 31, 2018 (1)	110
Closing balance as of December 31, 2019	117
Increase (Decrease) in Other Accrued Unbilled Revenues	7
Change in Contract Liability [Roll Forward]
Opening balance as of December 31, 2018 (1)	3
Closing balance as of December 31, 2019	3
Increase (Decrease) in Contract with Customer, Liability	0
Contract with Customer, Liability, Revenue Recognized	3
CERC Corp [Member]
Change in Accounts Receivable [Roll Forward]
Opening balance as of December 31, 2018 (1)	282
Closing balance as of December 31, 2019	282
Increase (Decrease) in Accounts Receivable	0
Change in Other Accrued Unbilled Revenues [Roll Forward]
Opening balance as of December 31, 2018 (1)	263
Closing balance as of December 31, 2019	250
Increase (Decrease) in Other Accrued Unbilled Revenues	$ (13)
[1]	Opening balances related to Vectren are as of February 1, 2019, and are thus excluded from the opening balance as of December 31, 2018.

Revenue Recognition Remaining P

Revenue Recognition Remaining Performance Obligations (Details) $ in Millions	Dec. 31, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 338
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	752
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	1,090
Infrastructure Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	254
Infrastructure Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	0
Infrastructure Services [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	254
Corporate and Other [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	84
Corporate and Other [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	752
Corporate and Other [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 836

Goodwill and Other Intangible_3

Goodwill and Other Intangibles (CenterPoint Energy and CERC) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill		$ 5,164		$ 867
Goodwill, Acquired During Period		0
Goodwill impairment charge recorded from annual impairment test		48		0	$ 0
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		411		106
Accumulated Amortization		(90)		(41)
Net Balance		321		65
Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2)		24		0	0
2020		29
2021		25
2022		25
2023		24
2024		22
Deferred Tax Liabilities, Net, Noncurrent		3,928		3,239
Customer Relationships [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		286	[1]	86
Accumulated Amortization		(43)	[1]	(27)
Net Balance		243	[1]	59
Covenants Not To Compete [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		4		4
Accumulated Amortization		(4)		(3)
Net Balance		0		1
Trade Names [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		58	[1]	0
Accumulated Amortization		(5)	[1]	0
Net Balance		53	[1]	0
Construction backlog [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		27	[1],[2]	0
Accumulated Amortization		(23)	[1],[2]	0
Net Balance		4	[1],[2]	0
Operation and maintenance agreements [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		12	[1],[2]	0
Accumulated Amortization		(1)	[1],[2]	0
Net Balance		11	[1],[2]	0
Other [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		24	[1]	16
Accumulated Amortization		(14)	[1]	(11)
Net Balance		10	[1]	5
Indiana Electric Integrated [Member]
Goodwill [Line Items]
Goodwill		1,121		0
Goodwill, Acquired During Period	[3]	1,121
Goodwill impairment charge recorded from annual impairment test		0
Natural Gas Distribution [Member]
Goodwill [Line Items]
Goodwill		3,312		746
Goodwill, Acquired During Period	[3]	2,566
Goodwill impairment charge recorded from annual impairment test		0
Energy Services [Member]
Goodwill [Line Items]
Goodwill	[4]	62		110
Goodwill impairment charge recorded from annual impairment test		48
Accumulated goodwill impairment charge recorded in 2012		252
Finite-Lived Intangible Assets, Net [Abstract]
Deferred Tax Liabilities, Net, Noncurrent		25
Goodwill, Impairment Loss, Net of Tax		45
Infrastructure Services [Member]
Goodwill [Line Items]
Goodwill		220		0
Goodwill, Acquired During Period	[3]	220
Goodwill impairment charge recorded from annual impairment test		0
Finite-Lived Intangible Assets, Net [Abstract]
Deferred Tax Liabilities, Net, Noncurrent		123
Corporate and Other [Member]
Goodwill [Line Items]
Goodwill		449		11
Goodwill, Acquired During Period	[3]	438
Goodwill impairment charge recorded from annual impairment test		0
Vectren acquisition [Member]
Goodwill [Line Items]
Goodwill, Acquired During Period	[3]	4,345
CERC Corp [Member]
Goodwill [Line Items]
Goodwill		819		867
Goodwill impairment charge recorded from annual impairment test		48		0	0
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		106		106
Accumulated Amortization		(50)		(41)
Net Balance		56		65
2020		6
2021		6
2022		6
2023		5
2024		5
Deferred Tax Liabilities, Net, Noncurrent		470		406
CERC Corp [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		86		86
Accumulated Amortization		(32)		(27)
Net Balance		54		59
CERC Corp [Member] | Covenants Not To Compete [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		4		4
Accumulated Amortization		(4)		(3)
Net Balance		0		1
CERC Corp [Member] | Other [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount		16		16
Accumulated Amortization		(14)		(11)
Net Balance		2		5
CERC Corp [Member] | Natural Gas Distribution [Member]
Goodwill [Line Items]
Goodwill		746		746
Goodwill impairment charge recorded from annual impairment test		0
CERC Corp [Member] | Energy Services [Member]
Goodwill [Line Items]
Goodwill	[5]	62		110
Goodwill impairment charge recorded from annual impairment test		48
Accumulated goodwill impairment charge recorded in 2012		252
Finite-Lived Intangible Assets, Net [Abstract]
Deferred Tax Liabilities, Net, Noncurrent		25
Goodwill, Impairment Loss, Net of Tax		48
CERC Corp [Member] | Corporate and Other [Member]
Goodwill [Line Items]
Goodwill		11		11
Goodwill impairment charge recorded from annual impairment test		0
Depreciation and amortization expense [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2)		25	[6],[7]	10	13
Depreciation and amortization expense [Member] | CERC Corp [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2)		9		10	13
Non-utility cost of revenues [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2)		24	[7]	$ 0	$ 0
Vectren [Member]
Goodwill [Line Items]
Goodwill		4,339
Vectren [Member] | Depreciation and amortization expense [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense of intangible assets recorded in Depreciation and amortization (1) (2)		$ 17
[1]	The fair value of intangible assets acquired through acquisitions has been finalized. See Note 4 .
[2]	Amortization expense related to the operation and maintenance agreements and construction backlog is included in Non-utility cost of revenues, including natural gas on CenterPoint Energy’s Statements of Consolidated Income.
[3]	This represents the allocation of goodwill to reportable segments from the Merger, changes from preliminary amounts previously reported and includes the final determination of fair value for each reportable segment. See Note 4
[4]	Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012. As of December 31, 2019, CenterPoint Energy and CERC identified a triggering event to perform an interim goodwill impairment test and recognized a goodwill impairment on their Energy Services reporting unit which is included in Goodwill impairment on CenterPoint Energy’s and CERC’s Consolidated Statements of Income.
[5]	Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012.
[6]	Includes $17 million for the year ended December 31, 2019 of amortization expense related to intangibles acquired in the Merger.
[7]	The fair value of intangible assets, and related amortization assumptions, acquired through acquisitions during the year ended December 31, 2019 , has been finalized. See Note 4 .

Regulatory Matters Regulatory A

Regulatory Matters Regulatory Assets and Regulatory Liabilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Schedule of Regulatory Assets and Liabilities [Line Items]
Securitized regulatory assets		$ 788		$ 1,059
Unrecognized equity return (2)	[1]	(168)		(213)
Unamortized loss on reacquired debt (3)	[2]	62		68
Non-current regulatory assets		2,117		1,967
Total regulatory assets		2,129		2,044
Non-current regulatory liabilities		3,474		2,525
Total regulatory liabilities		3,521		2,563
Total regulatory assets and liabilities, net		(1,392)		(519)
Amount of allowed equity return on the true-up balance that was recognized in the period		45		74		$ 42
Prepaid Expenses and Other Current Assets [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current regulatory assets (1)	[3]	12		77
Other Current Liabilities [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current regulatory liabilities (6)	[4]	47		38
Amounts related to TCJA [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities	[5]	1,582		1,323
Removal Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities		1,429		886
Other Regulatory Assets (Liabilities) [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities		463		316
Pension and Other Postretirement Plans Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	637		725
Amounts related to TCJA [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2],[5]	30		33
Asset Retirement Obligation Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	131		109
Other Regulatory Assets (Liabilities) [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets		422		37
Remaining amounts of regulatory assets for which no return on investment during recovery period is provided		147	[6]	81	[2]
Hurricane Harvey [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	68		68
Houston Electric [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Securitized regulatory assets		788		1,059
Unrecognized equity return (2)	[1]	(168)		(213)
Unamortized loss on reacquired debt (3)	[2]	62		68
Non-current regulatory assets		915		1,124
Total regulatory assets		915		1,124
Non-current regulatory liabilities		1,288		1,298
Total regulatory liabilities		1,288		1,315
Total regulatory assets and liabilities, net		(373)		(191)
Amount of allowed equity return on the true-up balance that was recognized in the period		45		74		$ 42
Houston Electric [Member] | Prepaid Expenses and Other Current Assets [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current regulatory assets (1)	[3]	0		0
Houston Electric [Member] | Other Current Liabilities [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current regulatory liabilities (6)	[4]	0		17
Houston Electric [Member] | Amounts related to TCJA [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities	[5]	821		847
Houston Electric [Member] | Removal Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities		244		269
Houston Electric [Member] | Other Regulatory Assets (Liabilities) [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities		223		182
Houston Electric [Member] | Pension and Other Postretirement Plans Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	34		33
Houston Electric [Member] | Amounts related to TCJA [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2],[5]	23		23
Houston Electric [Member] | Asset Retirement Obligation Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	26		24
Houston Electric [Member] | Other Regulatory Assets (Liabilities) [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets		29		11
Remaining amounts of regulatory assets for which no return on investment during recovery period is provided		57	[6]	55	[2]
Houston Electric [Member] | Hurricane Harvey [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	64		64
CERC Corp [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Securitized regulatory assets		0		0
Unrecognized equity return (2)	[1]	0		0
Unamortized loss on reacquired debt (3)	[2]	0		0
Non-current regulatory assets		191		181
Total regulatory assets		203		258
Non-current regulatory liabilities		1,219		1,227
Total regulatory liabilities		1,266		1,248
Total regulatory assets and liabilities, net		(1,063)		(990)
CERC Corp [Member] | Prepaid Expenses and Other Current Assets [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current regulatory assets (1)	[3]	12		77
CERC Corp [Member] | Other Current Liabilities [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current regulatory liabilities (6)	[4]	47		21
CERC Corp [Member] | Amounts related to TCJA [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities	[5]	442		476
CERC Corp [Member] | Removal Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities		637		617
CERC Corp [Member] | Other Regulatory Assets (Liabilities) [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory liabilities		140		134
CERC Corp [Member] | Pension and Other Postretirement Plans Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	22		30
CERC Corp [Member] | Amounts related to TCJA [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2],[5]	7		10
CERC Corp [Member] | Asset Retirement Obligation Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	94		85
CERC Corp [Member] | Other Regulatory Assets (Liabilities) [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets		16		26
Remaining amounts of regulatory assets for which no return on investment during recovery period is provided		48	[6]	26	[2]
CERC Corp [Member] | Hurricane Harvey [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-current regulatory assets	[2]	$ 4		$ 4
[1]	The unrecognized equity return will be recognized as it is recovered in rates through 2024. The timing of CenterPoint Energy’s and Houston Electric’s recognition of the equity return will vary each period based on amounts actually collected during the period. The actual amounts recognized are adjusted at least annually to correct any over-collections or under-collections during the preceding 12 months. Year Ended December 31, 2019 2018 2017 CenterPoint Energy Houston Electric CenterPoint Energy Houston Electric CenterPoint Energy Houston Electric Allowed equity return recognized $ 45 $ 45 $ 74 $ 74 $ 42 $ 42
[2]	Substantially all of these regulatory assets are not earning a return.
[3]	Current regulatory assets are included in Prepaid expenses and other current assets in the Registrants’ respective Consolidated Balance Sheets.
[4]	Current regulatory liabilities are included in Other current liabilities in each of the Registrants’ respective Consolidated Balance Sheets.
[5]	The EDIT and deferred revenues will be recovered or refunded to customers as required by tax and regulatory authorities. See Note 15 for additional information.
[6]	Regulatory assets acquired in the Merger and not earning a return were recorded at fair value as of the Merger Date. Such fair value adjustments are recognized over time until the regulatory asset is recovered.

Regulatory Matters Houston Elec

Regulatory Matters Houston Electric Base Rate Case (Details) - USD ($) $ in Millions	Jan. 23, 2020	Apr. 05, 2019	Dec. 31, 2019	Dec. 31, 2018
Public Utilities, General Disclosures [Line Items]
Non-current regulatory assets			$ 2,117	$ 1,967
CenterPoint Energy Houston Electric 2019 Rate Case [Member]
Public Utilities, General Disclosures [Line Items]
Revenue increase		$ 194
Rate base		$ 6,400
Debt capital structure		50.00%
Equity capital structure		50.00%
Return on equity		10.40%
Houston Electric Stipulation and Settlement Agreement [Member] | Public Utility Commission of Texas [Member]
Public Utilities, General Disclosures [Line Items]
General mortgage bonds used as collateral			68
Subsequent Event [Member] | Houston Electric Stipulation and Settlement Agreement [Member] | Public Utility Commission of Texas [Member]
Public Utilities, General Disclosures [Line Items]
Revenue increase	$ 13
Debt capital structure	57.50%
Equity capital structure	42.50%
Return on equity	9.40%
Unprotected Excess Deferred Income Tax	$ 105
Rate Case Expense [Member] | Houston Electric Stipulation and Settlement Agreement [Member]
Public Utilities, General Disclosures [Line Items]
Non-current regulatory assets			$ 12

Stock-Based Incentive Compens_3

Stock-Based Incentive Compensation Plans and Employee Benefit Plans Stock Based Incentive Compensation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance under long-term incentive plans (in shares)		14,000
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]
Income tax benefit recognized related to LTIPs		$ 7		$ 6	$ 8
Actual tax benefit realized for tax deductions		$ 12		$ 5	$ 6
Performance Awards [Member]
Summary of nonvested shares [Roll Forward]
Nonvested, beginning of period (in shares)	[1]	3,818
Granted (in shares)	[1]	1,413
Forfeited or cancelled (in shares)	[1]	(825)
Vested and released to participants (in shares)	[1]	(1,074)
Nonvested, end of period (in shares)	[1]	3,332		3,818
Weighted average grant date fair value, nonvested, beginning of period (in dollars per share)	[1]	$ 23.91
Weighted average grant date fair values of awards granted (in dollars per share)		31.16	[1]	$ 26.74	$ 26.64
Weighted average grant date fair value, forfeited or cancelled (in dollars per share)	[1]	24.78
Weighted average grant date fair value, vested and released to participants (in dollars per share)	[1]	18.97
Weighted average grant date fair value, nonvested, end of period (in dollars per share)	[1]	$ 28.36		$ 23.91
Remaining average contractual life of nonvested shares outstanding (in years)		1 year 1 month 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested	[1],[2]	$ 53
Total intrinsic value of awards received by participants		36		$ 12	$ 7
Total grant date fair values of performance and stock awards which vested during the period		$ 20		$ 9	$ 5
Stock Awards [Member]
Summary of nonvested shares [Roll Forward]
Nonvested, beginning of period (in shares)		1,060
Granted (in shares)		470
Forfeited or cancelled (in shares)		(131)
Vested and released to participants (in shares)		(433)
Nonvested, end of period (in shares)		966		1,060
Weighted average grant date fair value, nonvested, beginning of period (in dollars per share)		$ 24.08
Weighted average grant date fair values of awards granted (in dollars per share)		31.07		$ 26.62	$ 26.77
Weighted average grant date fair value, forfeited or cancelled (in dollars per share)		27.95
Weighted average grant date fair value, vested and released to participants (in dollars per share)		20.72
Weighted average grant date fair value, nonvested, end of period (in dollars per share)		$ 28.46		$ 24.08
Remaining average contractual life of nonvested shares outstanding (in years)		1 year 2 months 12 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested	[2]	$ 26
Total intrinsic value of awards received by participants		15		$ 9	$ 9
Total grant date fair values of performance and stock awards which vested during the period		9		7	7
Performance and Stock Awards [Member]
Summary of nonvested shares [Roll Forward]
Unrecognized compensation cost related to non-vested performance and stock awards		$ 34
Weighted average period of recognition (in years)		1 year 8 months 12 days
Operation And Maintenance Expense [Member]
Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]
LTIP compensation expense	[3]	$ 28		$ 26	$ 21
[1]	Reflects maximum performance achievement.
[2]	Reflects the impact of current expectations of achievement and stock price.
[3]	Amounts presented in the table above are included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income and shown prior to any amounts capitalized.

Stock-Based Incentive Compens_4

Stock-Based Incentive Compensation Plans and Employee Benefit Plans Pension and Postretirement Benefits (Details) - USD ($) $ in Millions		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Amounts recognized in balance sheets
Other liabilities-benefit obligations		$ (754)		$ (796)		$ (754)		$ (796)
Changes in plan assets and benefit obligations recognized in other comprehensive income
Amortization of net loss	[1]					(8)		(6)
Prior service cost (2)	[1]					(1)		(1)
Other Postretirement Benefits Plan [Member]
Components of net periodic costs [Abstract]
Service cost (1)	[2]					3		2		$ 2
Interest cost (2)	[3]					15		13		16
Expected return on plan assets (2)	[3]					(5)		(5)		(5)
Amortization of prior service cost (2)	[3]					(5)		(5)		(5)
Net periodic cost (credit)						$ 8		$ 5		$ 8
Assumptions used to determine net periodic benefit (income) cost
Discount rate						3.20%		3.60%		4.15%
Expected return on plan assets		3.95%	[4]	4.60%	[4]	4.60%		4.55%		4.50%
Change in benefit obligation [Roll Forward]
Benefit obligation, beginning of year						$ 331		$ 386
Plan obligations assumed in Merger						37		0
Service cost (1)	[2]					3		2		$ 2
Interest cost (2)	[3]					15		13		16
Participant contributions						8		7
Benefits paid						(26)		(25)
Plan amendment						9		0
Actuarial (gain) loss (1)	[5]					(21)		(52)
Benefit obligation, end of year		$ 356		$ 331		356		331		386
Change in plan assets [Rollforward]
Fair value of plan assets, beginning of year						114		120
Employer contributions						17		14
Participant contributions						8		7
Benefits paid						(26)		(25)
Actual investment return						15		(2)
Fair value of plan assets, end of year		128		114		128		114		$ 120
Funded status of plan
Funded status, end of year		(228)		(217)		(228)		(217)
Amounts recognized in balance sheets
Current liabilities-other		(8)		(6)		(8)		(6)
Other liabilities-benefit obligations		(220)		(211)		(220)		(211)
Net liability, end of year		$ (228)		$ (217)		$ (228)		$ (217)
Discount rate (2)		3.25%	[6]	4.35%	[6]	3.25%	[6]	4.35%	[6]	3.60%
Expected return on plan assets (3)		3.95%	[4]	4.60%	[4]	4.60%		4.55%		4.50%
Prescription drug cost trend rate assumed for the next year - Pre-65						8.00%		9.20%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)		4.50%		4.50%		4.50%		4.50%
Annualized individual discount rates based on time period, minimum						6 months
Annualized individual discount rates based on time period, maximum						99 years
Amounts recognized in accumulated other comprehensive loss
Unrecognized actuarial loss (gain)		$ (16)		$ (7)		$ (16)		$ (7)
Unrecognized prior service cost		7		5		7		5
Deferred Tax Benefit On Accumulated Other Comprehensive Income		0		0		0		0
Net amount recognized in accumulated other comprehensive loss (gain)		$ (9)		$ (2)		(9)		(2)
Changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)						(8)
Amortization of net loss						0
Prior service cost (2)						1
Total recognized in comprehensive income						(7)
Total expense recognized in net periodic cost and other comprehensive income						1
Pension Plan [Member]
Components of net periodic costs [Abstract]
Service cost (1)						40		37
Interest cost (2)						96		79
Net periodic cost (credit)						$ 93		$ 61		$ 95
Assumptions used to determine net periodic benefit (income) cost
Discount rate						4.35%		3.65%		4.15%
Expected return on plan assets		5.75%	[7]	6.00%	[7]	6.00%		6.00%		6.00%
Rate of increase in compensation levels						4.60%		4.45%		4.50%
Change in benefit obligation [Roll Forward]
Benefit obligation, beginning of year						$ 2,013		$ 2,225
Plan obligations assumed in Merger						332		0
Service cost (1)						40		37
Interest cost (2)						96		79
Benefits paid						(244)		(201)
Plan amendment						1		0
Actuarial (gain) loss (1)	[8]					216		(127)
Curtailment						(1)		0
Benefit obligation, end of year		$ 2,453		$ 2,013		2,453		2,013		$ 2,225
Change in plan assets [Rollforward]
Fair value of plan assets, beginning of year						1,516		1,801
Plan assets assumed in Merger						286		0
Employer contributions						109		69
Benefits paid						(244)		(201)
Actual investment return						338		(153)
Fair value of plan assets, end of year		2,005		1,516		2,005		1,516		$ 1,801
Funded status of plan
Funded status, end of year		(448)		(497)		(448)		(497)
Amounts recognized in balance sheets
Current liabilities-other		(8)		(7)		(8)		(7)
Other liabilities-benefit obligations		(440)		(490)		(440)		(490)
Net liability, end of year		$ (448)		$ (497)		$ (448)		$ (497)
Discount rate (2)		3.20%	[9]	4.35%	[9]	3.20%	[9]	4.35%	[9]	3.65%
Expected return on plan assets (3)		5.75%	[7]	6.00%	[7]	6.00%		6.00%		6.00%
Rate of increase in compensation levels		4.95%		4.60%		4.95%		4.60%
Interest crediting rate		3.25%		3.75%		3.25%		3.75%
Annualized individual discount rates based on time period, minimum						6 months
Annualized individual discount rates based on time period, maximum						99 years
Amounts recognized in accumulated other comprehensive loss
Unrecognized actuarial loss (gain)		$ 105		$ 109		$ 105		$ 109
Unrecognized prior service cost		0		1		0		1
Deferred Tax Benefit On Accumulated Other Comprehensive Income		0		0		0		0
Net amount recognized in accumulated other comprehensive loss (gain)		105		110		105		110
Changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)						4
Amortization of net loss						(8)
Prior service cost (2)						(1)
Total recognized in comprehensive income						(5)
Total expense recognized in net periodic cost and other comprehensive income						87
Pension benefits that have accumulated benefit obligations in excess of plan assets
Accumulated benefit obligation		2,352		1,930		2,352		1,930
Projected benefit obligation		2,385		1,952		2,385		1,952
Fair value of plan assets		2,005		1,516		2,005		1,516
Accumulated benefit obligation for all defined benefit pension plans		2,420		1,991		2,420		1,991
Non-qualified Pension Plan [Member]
Change in plan assets [Rollforward]
Employer contributions						23
Pension benefits that have accumulated benefit obligations in excess of plan assets
Accumulated benefit obligation		68		61		68		61
Projected benefit obligation		68		61		68		61
Fair value of plan assets		$ 0		$ 0		$ 0		$ 0
Minimum [Member] | Other Postretirement Benefits Plan [Member]
Amounts recognized in balance sheets
Health care cost trend rate assumed for the next year		5.50%		5.95%		5.50%		5.95%
Year that the cost trend rates reach the ultimate trend rate						2028		2026
Maximum [Member] | Other Postretirement Benefits Plan [Member]
Amounts recognized in balance sheets
Health care cost trend rate assumed for the next year		5.75%		28.60%		5.75%		28.60%
Year that the cost trend rates reach the ultimate trend rate						2029		2027
CERC Corp [Member]
Amounts recognized in balance sheets
Other liabilities-benefit obligations		$ (83)		$ (93)		$ (83)		$ (93)
Changes in plan assets and benefit obligations recognized in other comprehensive income
Amortization of net loss	[1]					0		0
Prior service cost (2)	[1]					0		(1)
CERC Corp [Member] | Other Postretirement Benefits Plan [Member]
Components of net periodic costs [Abstract]
Service cost (1)	[2]					1		1		$ 1
Interest cost (2)	[3]					5		4		5
Expected return on plan assets (2)	[3]					(1)		(1)		(1)
Amortization of prior service cost (2)	[3]					1		1		1
Net periodic cost (credit)						$ 6		$ 5		$ 6
Assumptions used to determine net periodic benefit (income) cost
Discount rate						3.20%		3.60%		4.15%
Expected return on plan assets		3.35%	[4]	4.15%	[4]	4.15%		3.85%		3.60%
Change in benefit obligation [Roll Forward]
Benefit obligation, beginning of year						$ 110		$ 109
Plan obligations assumed in Merger						0		0
Service cost (1)	[2]					1		1		$ 1
Interest cost (2)	[3]					5		4		5
Participant contributions						4		4
Benefits paid						(8)		(9)
Plan amendment						5		0
Actuarial (gain) loss (1)	[5]					(15)		(1)
Benefit obligation, end of year		$ 102		$ 110		102		110		109
Change in plan assets [Rollforward]
Fair value of plan assets, beginning of year						25		26
Employer contributions						3		4
Participant contributions						4		4
Benefits paid						(8)		(9)
Actual investment return						3		0
Fair value of plan assets, end of year		27		25		27		25		$ 26
Funded status of plan
Funded status, end of year		(75)		(85)		(75)		(85)
Amounts recognized in balance sheets
Current liabilities-other		(3)		(3)		(3)		(3)
Other liabilities-benefit obligations		(72)		(82)		(72)		(82)
Net liability, end of year		$ (75)		$ (85)		$ (75)		$ (85)
Discount rate (2)		3.25%	[6]	4.35%	[6]	3.25%	[6]	4.35%	[6]	3.60%
Expected return on plan assets (3)		3.35%	[4]	4.15%	[4]	4.15%		3.85%		3.60%
Prescription drug cost trend rate assumed for the next year - Pre-65						8.00%		9.20%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)		4.50%		4.50%		4.50%		4.50%
Annualized individual discount rates based on time period, minimum						6 months
Annualized individual discount rates based on time period, maximum						99 years
Amounts recognized in accumulated other comprehensive loss
Unrecognized actuarial loss (gain)		$ (12)		$ (3)		$ (12)		$ (3)
Unrecognized prior service cost		7		5		7		5
Deferred Tax Benefit On Accumulated Other Comprehensive Income		0		(9)		0		(9)
Net amount recognized in accumulated other comprehensive loss (gain)		$ (5)		$ (7)		(5)		$ (7)
Changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)						(6)
Amortization of net loss						0
Prior service cost (2)						(1)
Total recognized in comprehensive income						(7)
Total expense recognized in net periodic cost and other comprehensive income						(1)
CERC Corp [Member] | Non-qualified Pension Plan [Member]
Change in plan assets [Rollforward]
Employer contributions						$ 0
CERC Corp [Member] | Minimum [Member] | Other Postretirement Benefits Plan [Member]
Amounts recognized in balance sheets
Health care cost trend rate assumed for the next year		5.50%		5.95%		5.50%		5.95%
Year that the cost trend rates reach the ultimate trend rate						2028		2026
CERC Corp [Member] | Maximum [Member] | Other Postretirement Benefits Plan [Member]
Amounts recognized in balance sheets
Health care cost trend rate assumed for the next year		5.75%		28.60%		5.75%		28.60%
Year that the cost trend rates reach the ultimate trend rate						2029		2027
Houston Electric [Member]
Amounts recognized in balance sheets
Other liabilities-benefit obligations		$ (75)		$ (91)		$ (75)		$ (91)
Changes in plan assets and benefit obligations recognized in other comprehensive income
Amortization of net loss	[1]					0		0
Prior service cost (2)	[1]					0		0
Houston Electric [Member] | Other Postretirement Benefits Plan [Member]
Components of net periodic costs [Abstract]
Service cost (1)	[2]					1		0		$ 1
Interest cost (2)	[3]					7		8		9
Expected return on plan assets (2)	[3]					(4)		(4)		(4)
Amortization of prior service cost (2)	[3]					(6)		(5)		(6)
Net periodic cost (credit)						$ (2)		$ (1)		$ 0
Assumptions used to determine net periodic benefit (income) cost
Discount rate						3.20%		3.60%		4.15%
Expected return on plan assets		4.05%	[4]	4.70%	[4]	4.70%		4.75%		4.75%
Change in benefit obligation [Roll Forward]
Benefit obligation, beginning of year						$ 166		$ 225
Plan obligations assumed in Merger						0		0
Service cost (1)	[2]					1		0		$ 1
Interest cost (2)	[3]					7		8		9
Participant contributions						2		2
Benefits paid						(13)		(13)
Plan amendment						3		0
Actuarial (gain) loss (1)	[5]					(4)		(56)
Benefit obligation, end of year		$ 162		$ 166		162		166		225
Change in plan assets [Rollforward]
Fair value of plan assets, beginning of year						89		93
Employer contributions						10		9
Participant contributions						2		2
Benefits paid						(13)		(13)
Actual investment return						13		(2)
Fair value of plan assets, end of year		101		89		101		89		$ 93
Funded status of plan
Funded status, end of year		(61)		(77)		(61)		(77)
Amounts recognized in balance sheets
Current liabilities-other		0		0		0		0
Other liabilities-benefit obligations		(61)		(77)		(61)		(77)
Net liability, end of year		$ (61)		$ (77)		$ (61)		$ (77)
Discount rate (2)		3.25%	[6]	4.35%	[6]	3.25%	[6]	4.35%	[6]	3.60%
Expected return on plan assets (3)		4.05%	[4]	4.70%	[4]	4.70%		4.75%		4.75%
Prescription drug cost trend rate assumed for the next year - Pre-65						8.00%		9.20%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)		4.50%		4.50%		4.50%		4.50%
Annualized individual discount rates based on time period, minimum						6 months
Annualized individual discount rates based on time period, maximum						99 years
Houston Electric [Member] | Non-qualified Pension Plan [Member]
Change in plan assets [Rollforward]
Employer contributions						$ 0
Houston Electric [Member] | Minimum [Member] | Other Postretirement Benefits Plan [Member]
Amounts recognized in balance sheets
Health care cost trend rate assumed for the next year		5.50%		5.95%		5.50%		5.95%
Year that the cost trend rates reach the ultimate trend rate						2028		2026
Houston Electric [Member] | Maximum [Member] | Other Postretirement Benefits Plan [Member]
Amounts recognized in balance sheets
Health care cost trend rate assumed for the next year		5.75%		28.60%		5.75%		28.60%
Year that the cost trend rates reach the ultimate trend rate						2029		2027
Operation And Maintenance Expense [Member] | Pension Plan [Member]
Components of net periodic costs [Abstract]
Service cost (1)	[10]					$ 40		$ 37		$ 36
Change in benefit obligation [Roll Forward]
Service cost (1)	[10]					40		37		36
Other Nonoperating Income (Expense) [Member] | Pension Plan [Member]
Components of net periodic costs [Abstract]
Interest cost (2)	[11]					96		79		89
Expected return on plan assets (2)	[11]					(105)		(107)		(97)
Amortization of prior service cost (2)	[11]					9		9		9
Amortization of net loss (2)	[11]					52		43		58
Settlement cost (2) (3)	[11]					2	[12]	0		0
Curtailment gain (2) (4)	[11]					(1)	[13]	0		0
Change in benefit obligation [Roll Forward]
Interest cost (2)	[11]					$ 96		$ 79		$ 89
[1]	Amounts are included in the computation of net periodic cost and are reflected in Other, net in each of the Registrants’ respective Statements of Consolidated Income.
[2]	Amounts presented in the table above are included in Operation and maintenance expense in each of the Registrants’ respective Statements of Consolidated Income, net of regulatory deferrals and amounts capitalized.
[3]	Amounts presented in the table above are included in Other, net in each of the Registrants’ respective Statements of Consolidated Income, net of regulatory deferrals.
[4]	The expected rate of return assumption was developed using the targeted asset allocation of the plans and the expected return for each asset class.
[5]	Significant sources of gain for 2019 include favorable cost trend rates and benefit claims experience in addition to the change in mortality projection scale from MP2018 to MP2019. Significant sources of gain for 2018 include the increase in the discount rate from 3.60% to 4.35% , favorable benefit claims experience and cost trend rates in addition to the change in mortality projection scale from MP2017 to MP2018.
[6]	The discount rate assumption was determined by matching the projected cash flows of the plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years.
[7]	The expected rate of return assumption was developed using the targeted asset allocation of CenterPoint Energy’s plans and the expected return for each asset class.
[8]	Significant sources of loss for 2019 include the decrease in discount rate from 4.35% to 3.20% . Significant sources of gain for 2018 include the increase in discount rate from 3.65% to 4.35% and the mortality projection scale change from MP2017 to MP2018.
[9]	The discount rate assumption was determined by matching the projected cash flows of CenterPoint Energy’s plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years.
[10]	Amounts presented in the table above are included in Operation and maintenance expense in CenterPoint Energy’s Statements of Consolidated Income, net of regulatory deferrals and amounts capitalized.
[11]	Amounts presented in the table above are included in Other, net in CenterPoint Energy’s Statements of Consolidated Income, net of regulatory deferrals.
[12]	A one-time, non-cash settlement cost is required when the total lump sum distributions or other settlements of plan benefit obligations during a plan year exceed the service cost and interest cost components of the net periodic cost for that year. In 2019, CenterPoint Energy recognized a non-cash settlement cost due to lump sum settlement payments.
[13]	A curtailment gain or loss is required when the expected future services of a significant number of employees are reduced or eliminated for the accrual of benefits. In 2019, CenterPoint Energy recognized a pension curtailment gain related to employees who were terminated after the Merger closed.

Stock-Based Incentive Compens_5

Stock-Based Incentive Compensation Plans and Employee Benefit Plans Multi-employer Plan (Details) - Multiemployer Plans, Pension [Member] $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 52
Approximate number of unions the Company contributed to on behalf of employees	215
Multiemployer Plans Average Contributions	$ 1
Multiemployer Plans Largest Contribution	$ 5
Number of multiemployer plans contributed to	72
Defined benefit plan, number of significant plans	8
Defined benefit plan, number of plans in red zone status receiving company contributions	4
Defined benefit plan, number of plans whereby company contributions exceed 5% of plan balance	5
Defined benefit plan, percentage threshold by which plan contributions are considered significant	5.00%
Number of plans in red zone status considered significant by the Company	0
Central Pension Fund [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 12
Multiemployer Plans, Certified Zone Status [Fixed List]	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	No
Multiemployer Plans, Surcharge [Fixed List]	No
Indiana Laborers Pension Fund [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 5
Multiemployer Plans, Certified Zone Status [Fixed List]	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	No
Multiemployer Plans, Surcharge [Fixed List]	No
Pipeline Industry Benefit Fund [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 5
Multiemployer Plans, Certified Zone Status [Fixed List]	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	No
Multiemployer Plans, Surcharge [Fixed List]	No
Laborers District Fund of Ohio [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 4
Multiemployer Plans, Certified Zone Status [Fixed List]	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	No
Multiemployer Plans, Surcharge [Fixed List]	No
Ohio Operating Engineers Pension Fund [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 3
Multiemployer Plans, Certified Zone Status [Fixed List]	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	No
Multiemployer Plans, Surcharge [Fixed List]	No
Operating Eng. Local 324 Fund [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 3
Multiemployer Plans, Certified Zone Status [Fixed List]	Red
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	Implemented
Multiemployer Plans, Surcharge [Fixed List]	No
Minnesota Laborers Pension Fund [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 3
Multiemployer Plans, Certified Zone Status [Fixed List]	Green
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	No
Multiemployer Plans, Surcharge [Fixed List]	No
Laborers' Combined Fund of Western Pennsylvania [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 2
Multiemployer Plans, Certified Zone Status [Fixed List]	Red
Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan [Fixed List]	Implemented
Multiemployer Plans, Surcharge [Fixed List]	No
Other Pension Funds [Member]
Multiemployer Plans [Line Items]
Multiemployer Plan, Contributions by Employer	$ 15

Stock-Based Incentive Compens_6

Stock-Based Incentive Compensation Plans and Employee Benefit Plans Plan Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Savings Plan [Abstract]
Defined Contribution Plan, Cost	[1]	$ 58		$ 43		$ 41
Postemployment Benefits [Abstract]
Postemployment Benefits, Period Expense		2		3		6
Other Non-Qualified Plans [Abstract]
Benefit expense related to deferred compensation plans		4		$ 3		$ 3
Non-qualified Pension Plan [Member]
Total contributions to the plans during the period		23
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 7
Pension Plan [Member]
Discount Rate		3.20%	[2]	4.35%	[2]	3.65%
Plan assets, fair value		$ 2,005		$ 1,516		$ 1,801
Obligation To Return Cash Received As Collateral From Securities Lending,		(61)		(77)
Defined Benefits Plan, Fair Value Of Plan Assets, Excluding Investments Measured at Net Asset Value		1,339		860
Defined Benefit Plan, Contribution by Employer, Qualified Plan		86
Total contributions to the plans during the period		109		$ 69
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		76
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Pension benefit payments 2020		180
Pension benefit payments 2021		178
Pension benefit payments 2022		180
Pension benefit payments 2023		181
Pension benefit payments 2024		177
Pension benefit payments 2025 - 2029		$ 824
Other Non-Qualified Plans [Abstract]
Annualized individual discount rates based on time period, minimum		6 months
Annualized individual discount rates based on time period, maximum		99 years
Postretirement Benefits [Member]
Discount Rate		3.25%	[3]	4.35%	[3]	3.60%
Plan assets, fair value		$ 128		$ 114		$ 120
Total contributions to the plans during the period		17		14
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		17
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Pension benefit payments 2020		18
Pension benefit payments 2021		18
Pension benefit payments 2022		19
Pension benefit payments 2023		20
Pension benefit payments 2024		21
Pension benefit payments 2025 - 2029		$ 112
Other Non-Qualified Plans [Abstract]
Annualized individual discount rates based on time period, minimum		6 months
Annualized individual discount rates based on time period, maximum		99 years
Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		$ 564		442
Obligation To Return Cash Received As Collateral From Securities Lending,		(61)		(77)
Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		775		418
Obligation To Return Cash Received As Collateral From Securities Lending,		0		0
Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Obligation To Return Cash Received As Collateral From Securities Lending,		0		0
U.S. Equity [Member] | Pension Plan [Member]
Plan assets, fair value		69		60
U.S. Equity [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		69		60
U.S. Equity [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
U.S. Equity [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Cash and Cash Equivalents [Member] | Pension Plan [Member]
Plan assets, fair value		(7)		19
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		(7)		19
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Investment grade or above [Member] | Pension Plan [Member]
Plan assets, fair value		699		368
Investment grade or above [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Investment grade or above [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		699		368
Investment grade or above [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Cash received as collateral from securities [Member] | Pension Plan [Member]
Plan assets, fair value		61		77
Cash received as collateral from securities [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		61		77
Cash received as collateral from securities [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Cash received as collateral from securities [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
U.S. treasuries [Member] | Pension Plan [Member]
Plan assets, fair value		232		196
U.S. treasuries [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		232		196
U.S. treasuries [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
U.S. treasuries [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Mortgage backed securities [Member] | Pension Plan [Member]
Plan assets, fair value		8		6
Mortgage backed securities [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Mortgage backed securities [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		8		6
Mortgage backed securities [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Asset backed securities [Member] | Pension Plan [Member]
Plan assets, fair value		3		1
Asset backed securities [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Asset backed securities [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		3		1
Asset backed securities [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Municipal bonds [Member] | Pension Plan [Member]
Plan assets, fair value		44		27
Municipal bonds [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Municipal bonds [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		44		27
Municipal bonds [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Mutual funds [Member] | Pension Plan [Member]
Plan assets, fair value	[4]	270		167
Mutual funds [Member] | Postretirement Benefits [Member]
Plan assets, fair value		$ 128		$ 114
Mutual funds [Member] | International Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		31.00%		85.00%
Mutual funds [Member] | International Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		8.00%		7.00%
Mutual funds [Member] | U.S. Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		49.00%		15.00%
Mutual funds [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		21.00%		19.00%
Mutual funds [Member] | Real Estate Funds [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		1.00%		0.00%
Mutual funds [Member] | Fixed Income Funds [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		19.00%		0.00%
Mutual funds [Member] | Fixed Income Funds [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		71.00%		74.00%
Mutual funds [Member] | Emerging Market Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage				34.00%
Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		$ 270		$ 167
Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		128		114
Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		0		0
Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		0		0
International government bonds [Member] | Pension Plan [Member]
Plan assets, fair value		21		16
International government bonds [Member] | Fair Value, Inputs, Level 1 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
International government bonds [Member] | Fair Value, Inputs, Level 2 [Member] | Pension Plan [Member]
Plan assets, fair value		21		16
International government bonds [Member] | Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member]
Plan assets, fair value		0		0
Common Collective Trust Funds [Member] | Pension Plan [Member]
Plan assets, fair value	[4],[5]	$ 666		$ 656
Common Collective Trust Funds [Member] | International Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		29.00%		41.00%
Common Collective Trust Funds [Member] | U.S. Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		51.00%		5.00%
Common Collective Trust Funds [Member] | Real Estate Funds [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		6.00%		0.00%
Common Collective Trust Funds [Member] | Fixed Income Funds [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		14.00%		54.00%
Common Collective Trust Funds [Member] | Emerging Market Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage				4.00%
Benefit Obligation [Member]
Postemployment Benefits [Abstract]
Postemployment benefit obligations		$ 11		$ 11
Other Non-Qualified Plans [Abstract]
Other non-qualified plans benefit obligations deferred compensation		41		42
Benefit obligations related to split-dollar life insurance arrangements		$ 32		36
Minimum [Member] | U.S. Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		19.00%
Minimum [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		13.00%
Minimum [Member] | International Developed Market Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		8.00%
Minimum [Member] | International Developed Market Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		3.00%
Minimum [Member] | Real Estate Funds [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		3.00%
Minimum [Member] | Fixed Income [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		52.00%
Minimum [Member] | Fixed Income [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		69.00%
Minimum [Member] | Cash and Cash Equivalents [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Minimum [Member] | Cash and Cash Equivalents [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Maximum [Member] | U.S. Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		29.00%
Maximum [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		23.00%
Maximum [Member] | International Developed Market Equity [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		18.00%
Maximum [Member] | International Developed Market Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		13.00%
Maximum [Member] | Real Estate Funds [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		9.00%
Maximum [Member] | Fixed Income [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		62.00%
Maximum [Member] | Fixed Income [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		79.00%
Maximum [Member] | Cash and Cash Equivalents [Member] | Pension Plan [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		2.00%
Maximum [Member] | Cash and Cash Equivalents [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		2.00%
Common Stock [Member] | CenterPoint Energy [Member]
Savings Plan [Abstract]
Number of Common stock held by the savings plan (in shares)		11,051,800
Percentage of investment in common stocks (in hundredths)		13.00%
Defined Contribution Plan, Maximum Limit Of Account Balance In Company Stock, Percentage		25.00%
Houston Electric [Member]
Savings Plan [Abstract]
Defined Contribution Plan, Cost	[1]	$ 18		17		17
Postemployment Benefits [Abstract]
Postemployment Benefits, Period Expense		1		4		1
Other Non-Qualified Plans [Abstract]
Benefit expense related to deferred compensation plans		1		$ 1		$ 1
Houston Electric [Member] | Non-qualified Pension Plan [Member]
Total contributions to the plans during the period		0
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		0
Houston Electric [Member] | Pension Plan [Member]
Defined Benefit Plan, Contribution by Employer, Qualified Plan		0
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 0
Houston Electric [Member] | Postretirement Benefits [Member]
Discount Rate		3.25%	[3]	4.35%	[3]	3.60%
Plan assets, fair value		$ 101		$ 89		$ 93
Total contributions to the plans during the period		10		9
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		9
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Pension benefit payments 2020		8
Pension benefit payments 2021		8
Pension benefit payments 2022		9
Pension benefit payments 2023		10
Pension benefit payments 2024		10
Pension benefit payments 2025 - 2029		$ 54
Other Non-Qualified Plans [Abstract]
Annualized individual discount rates based on time period, minimum		6 months
Annualized individual discount rates based on time period, maximum		99 years
Houston Electric [Member] | Mutual funds [Member] | Postretirement Benefits [Member]
Plan assets, fair value		$ 101		$ 89
Houston Electric [Member] | Mutual funds [Member] | International Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		8.00%		7.00%
Houston Electric [Member] | Mutual funds [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		21.00%		19.00%
Houston Electric [Member] | Mutual funds [Member] | Fixed Income Funds [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		71.00%		74.00%
Houston Electric [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		$ 101		$ 89
Houston Electric [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		0		0
Houston Electric [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		0		0
Houston Electric [Member] | Benefit Obligation [Member]
Postemployment Benefits [Abstract]
Postemployment benefit obligations		3		3
Other Non-Qualified Plans [Abstract]
Other non-qualified plans benefit obligations deferred compensation		8		9
Benefit obligations related to split-dollar life insurance arrangements		$ 1		1
Houston Electric [Member] | Minimum [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		13.00%
Houston Electric [Member] | Minimum [Member] | International Developed Market Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		3.00%
Houston Electric [Member] | Minimum [Member] | Fixed Income [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		69.00%
Houston Electric [Member] | Minimum [Member] | Cash and Cash Equivalents [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
Houston Electric [Member] | Maximum [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		23.00%
Houston Electric [Member] | Maximum [Member] | International Developed Market Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		13.00%
Houston Electric [Member] | Maximum [Member] | Fixed Income [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		79.00%
Houston Electric [Member] | Maximum [Member] | Cash and Cash Equivalents [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		2.00%
Houston Electric [Member] | Common Stock [Member] | CenterPoint Energy [Member]
Savings Plan [Abstract]
Number of Common stock held by the savings plan (in shares)		11,051,800
Percentage of investment in common stocks (in hundredths)		13.00%
Defined Contribution Plan, Maximum Limit Of Account Balance In Company Stock, Percentage		25.00%
CERC Corp [Member]
Savings Plan [Abstract]
Defined Contribution Plan, Cost	[1]	$ 18		18		17
Postemployment Benefits [Abstract]
Postemployment Benefits, Period Expense		1		1		4
Other Non-Qualified Plans [Abstract]
Benefit expense related to deferred compensation plans		0		$ 0		$ 0
CERC Corp [Member] | Non-qualified Pension Plan [Member]
Total contributions to the plans during the period		0
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		0
CERC Corp [Member] | Pension Plan [Member]
Defined Benefit Plan, Contribution by Employer, Qualified Plan		0
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 0
CERC Corp [Member] | Postretirement Benefits [Member]
Discount Rate		3.25%	[3]	4.35%	[3]	3.60%
Plan assets, fair value		$ 27		$ 25		$ 26
Total contributions to the plans during the period		3		4
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		3
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Pension benefit payments 2020		5
Pension benefit payments 2021		4
Pension benefit payments 2022		5
Pension benefit payments 2023		5
Pension benefit payments 2024		6
Pension benefit payments 2025 - 2029		$ 30
Other Non-Qualified Plans [Abstract]
Annualized individual discount rates based on time period, minimum		6 months
Annualized individual discount rates based on time period, maximum		99 years
CERC Corp [Member] | Mutual funds [Member] | Postretirement Benefits [Member]
Plan assets, fair value		$ 27		$ 25
CERC Corp [Member] | Mutual funds [Member] | International Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		7.00%		6.00%
CERC Corp [Member] | Mutual funds [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		24.00%		21.00%
CERC Corp [Member] | Mutual funds [Member] | Fixed Income Funds [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage		69.00%		73.00%
CERC Corp [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		$ 27		$ 25
CERC Corp [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		0		0
CERC Corp [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member] | Postretirement Benefits [Member]
Plan assets, fair value		0		0
CERC Corp [Member] | Benefit Obligation [Member]
Postemployment Benefits [Abstract]
Postemployment benefit obligations		7		7
Other Non-Qualified Plans [Abstract]
Other non-qualified plans benefit obligations deferred compensation		3		3
Benefit obligations related to split-dollar life insurance arrangements		$ 0		$ 0
CERC Corp [Member] | Minimum [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		15.00%
CERC Corp [Member] | Minimum [Member] | International Developed Market Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		2.00%
CERC Corp [Member] | Minimum [Member] | Fixed Income [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		68.00%
CERC Corp [Member] | Minimum [Member] | Cash and Cash Equivalents [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		0.00%
CERC Corp [Member] | Maximum [Member] | U.S. Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		25.00%
CERC Corp [Member] | Maximum [Member] | International Developed Market Equity [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		12.00%
CERC Corp [Member] | Maximum [Member] | Fixed Income [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		78.00%
CERC Corp [Member] | Maximum [Member] | Cash and Cash Equivalents [Member] | Postretirement Benefits [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		2.00%
CERC Corp [Member] | Common Stock [Member] | CenterPoint Energy [Member]
Savings Plan [Abstract]
Number of Common stock held by the savings plan (in shares)		11,051,800
Percentage of investment in common stocks (in hundredths)		13.00%
Defined Contribution Plan, Maximum Limit Of Account Balance In Company Stock, Percentage		25.00%
[1]	Amounts presented in the table above are included in Operation and maintenance expense in the Registrants’ respective Statements of Consolidated Income and shown prior to any amounts capitalized.
[2]	The discount rate assumption was determined by matching the projected cash flows of CenterPoint Energy’s plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years.
[3]	The discount rate assumption was determined by matching the projected cash flows of the plans against a hypothetical yield curve of high-quality corporate bonds represented by a series of annualized individual discount rates from one-half to 99 years.
[4]	The amounts invested in mutual funds and common collective trust funds were allocated as follows: As of December 31, 2019 2018 Mutual Funds Common Collective Trust Funds Mutual Funds Common Collective Trust Funds International equities (1) 31 % 29 % 85 % 41 % U.S. equities 49 % 51 % 15 % 5 % Real estate 1 % 6 % — % — % Fixed income 19 % 14 % — % 54 % (1) The amounts invested in international equities for 2018 include allocations of 34% in mutual funds and 4% in common collective trust funds,which were previously reported as allocations in emerging market equities.
[5]	Represents investments in common collective trust funds.

Stock-Based Incentive Compens_7

Stock-Based Incentive Compensation Plans and Employee Benefit Plans Change in Control Agreements and Other Employee Matters (Details)	12 Months Ended
	Dec. 31, 2019salary_severance_benefits
Concentration Risk [Line Items]
Maximum Number Of Times Annual Salary Included In Severance Benefits	3
Workforce Subject to Collective Bargaining Arrangements Expiring in May 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	10.00%
Workforce Subject to Collective Bargaining Arrangements Expiring in March and May 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	2.00%
Workforce Subject to Collective Bargaining Arrangements Expiring in April 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	3.00%
Workforce Subject to Collective Bargaining Arrangements Expiring in December 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	4.00%
Workforce Subject to Collective Bargaining Arrangements Expiring in June and July 2022 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	5.00%
Workforce Subject to Collective Bargaining Arrangements Expiring in September 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Workforce Subject to Collective Bargaining Arrangements Expiring in October 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	1.00%
Workforce Subject to Collective Bargaining Arrangements Expiring Various Dates in 2020 to 2022 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	27.00%	[1]
Workforce Subject to Collective Bargaining Arrangements [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	52.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in May 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	51.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in March and May 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in April 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in December 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in June and July 2022 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in September 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in October 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring Various Dates in 2020 to 2022 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
Houston Electric [Member] | Workforce Subject to Collective Bargaining Arrangements [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	51.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in May 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in March and May 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	3.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in April 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	12.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in December 2020 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	7.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in June and July 2022 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	12.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in September 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring in October 2021 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements Expiring Various Dates in 2020 to 2022 [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%
CERC Corp [Member] | Workforce Subject to Collective Bargaining Arrangements [Member] | Employees Subject To Collective Bargaining Agreements [Member] | Labor Force Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	34.00%
[1]	Infrastructure Services negotiates various trade agreements through contractor associations. The two primary associations are the DCA and the PLCA. These trade agreements are with a variety of construction unions including Laborer’s International Union of North America, International Union of Operating Engineers, United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry, and Teamsters. The trade agreements have varying expiration dates in 2020, 2021 and 2022. In addition, these subsidiaries have various project agreements and small local agreements. These agreements expire upon completion of a specific project or on various dates throughout the year.

Derivative Instruments Derivati

Derivative Instruments Derivatives and Hedging (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Weather hedges term		10 years
Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member]
Recognized gain (loss) on weather hedges	[1]	$ 8		$ (4)	$ (1)
2019 to 2020 [Member] | Natural Gas Distribution [Member]
Weather hedge bilateral cap amount		8
2019 to 2020 [Member] | Electric Transmission & Distribution [Member]
Weather hedge bilateral cap amount		7
2019 to 2020 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]
Recognized gain (loss) on weather hedges		2		0	0
2019 to 2020 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission & Distribution [Member]
Recognized gain (loss) on weather hedges		3		0	0
2018 to 2019 [Member] | Natural Gas Distribution [Member]
Weather hedge bilateral cap amount		9
2018 to 2019 [Member] | Electric Transmission & Distribution [Member]
Weather hedge bilateral cap amount		8
2018 to 2019 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]
Recognized gain (loss) on weather hedges		0		0	0
2018 to 2019 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission & Distribution [Member]
Recognized gain (loss) on weather hedges		3		0	0
2017 to 2018 [Member] | Natural Gas Distribution [Member]
Weather hedge bilateral cap amount		8
2017 to 2018 [Member] | Electric Transmission & Distribution [Member]
Weather hedge bilateral cap amount		9
2017 to 2018 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]
Recognized gain (loss) on weather hedges		0		(2)	0
2017 to 2018 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission & Distribution [Member]
Recognized gain (loss) on weather hedges		0		(2)	0
2016 to 2017 [Member] | Electric Transmission & Distribution [Member]
Weather hedge bilateral cap amount		9
2016 to 2017 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission & Distribution [Member]
Recognized gain (loss) on weather hedges		$ 0		0	(1)
CERC Corp [Member]
Weather hedges term		10 years
CERC Corp [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member]
Recognized gain (loss) on weather hedges	[1]	$ 2		(2)	0
CERC Corp [Member] | 2019 to 2020 [Member] | Natural Gas Distribution [Member]
Weather hedge bilateral cap amount		8
CERC Corp [Member] | 2019 to 2020 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]
Recognized gain (loss) on weather hedges		2		0	0
CERC Corp [Member] | 2018 to 2019 [Member] | Natural Gas Distribution [Member]
Weather hedge bilateral cap amount		9
CERC Corp [Member] | 2018 to 2019 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]
Recognized gain (loss) on weather hedges		0		0	0
CERC Corp [Member] | 2017 to 2018 [Member] | Natural Gas Distribution [Member]
Weather hedge bilateral cap amount		8
CERC Corp [Member] | 2017 to 2018 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member]
Recognized gain (loss) on weather hedges		0		(2)	$ 0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest Rate Contract [Member]
Derivative Liability, Notional Amount		84	[2]	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Houston Electric [Member] | Interest Rate Contract [Member]
Derivative Liability, Notional Amount		0		0
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative Liability, Notional Amount		0	[2]	450
Cash Flow Hedging [Member] | Houston Electric [Member] | Interest Rate Contract [Member]
Derivative Liability, Notional Amount		$ 0		$ 450
[1]	Weather hedge gains (losses) are recorded in Revenues in the Statements of Consolidated Income.
[2]	Relates to interest rate derivative instruments at SIGECO.

Derivative Instruments Summary

Derivative Instruments Summary of Derivative Activity (Details) $ in Millions		12 Months Ended
		Dec. 31, 2019USD ($)Bcf	Dec. 31, 2018USD ($)Bcf	Dec. 31, 2017USD ($)
Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative gross volume notional amount (in Bcf) | Bcf		2,226	1,674
Gross Amounts Recognized	[1]	$ 51	$ 12
Gross Amounts Offset in the Consolidated Balance Sheets		63	19
Net Amount Presented in the Consolidated Balance Sheets	[2]	114	31
Derivative Assets Fair Value		292	220
Derivative Liabilities Fair Value		1,144	833
Derivative Asset		47	57
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item		(13)	1
Income Statement Impact of Derivative Activity [Abstract]
Total amounts presented in the statements of income in which the effects of hedges are recorded	[3]	4,029	4,364	$ 3,785
Gain (loss) on derivative instruments not designated as hedging instruments		(78)	(123)	260
Derivative, Credit Risk Related Contingent Features [Abstract]
Aggregate fair value of derivatives containing material adverse change provisions in a net liability position		1	1
Fair value of collateral already posted		0	0
Additional collateral required to be posted if credit risk contingent features triggered		1	0
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[4]	194	138
Energy Marketers [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[4]	16	24
Retail End Users [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[4],[5]	178	114
External Credit Rating, Investment Grade [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[6]	31	41
External Credit Rating, Investment Grade [Member] | Energy Marketers [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[6]	4	11
External Credit Rating, Investment Grade [Member] | Retail End Users [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[5],[6]	27	30
Current Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Asset	[2]	136	100
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item		(13)	1
Gross Amounts Recognized	[1]	224	166
Gross Amounts Offset		(88)	(66)
Other Noncurrent Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Asset	[2]	58	38
Gross Amounts Recognized	[1]	68	54
Gross Amounts Offset		(10)	(16)
Current Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Gross Amounts Recognized	[1]	(187)	(183)
Gross Amounts Offset		136	81
Derivative Liability	[2]	(51)	(102)
Other Noncurrent Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Gross Amounts Recognized	[1]	(54)	(25)
Gross Amounts Offset		25	20
Derivative Liability	[2]	(29)	(5)
Not Designated as Hedging Instrument [Member] | Current Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[7],[8],[9]	139	103
Derivative Liabilities Fair Value	[7],[8],[9]	3	3
Not Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[7],[8],[9]	58	38
Derivative Liabilities Fair Value	[7],[8],[9]	0	0
Not Designated as Hedging Instrument [Member] | Current Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[7],[8],[9]	73	62
Derivative Liabilities Fair Value	[7],[8],[9]	184	173
Not Designated as Hedging Instrument [Member] | Current Liabilities [Member] | IDS Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value		0	0
Derivative Liabilities Fair Value		893	601
Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Interest Rate Contract [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value		0	0
Derivative Liabilities Fair Value		10	0
Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[7],[8],[9]	10	16
Derivative Liabilities Fair Value	[7],[8],[9]	$ 54	$ 25
Long [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative gross volume notional amount (in Bcf) | Bcf		374	140
Houston Electric [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value		$ 0	$ 0
Derivative Liabilities Fair Value		$ 0	$ 24
CERC Corp [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative gross volume notional amount (in Bcf) | Bcf		2,226	1,674
Gross Amounts Recognized	[1]	$ 73	$ 12
Gross Amounts Offset in the Consolidated Balance Sheets		63	19
Net Amount Presented in the Consolidated Balance Sheets	[2]	136	31
CERC Corp [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value		292	220
Derivative Liabilities Fair Value		219	208
Derivative Asset		47	57
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item		(13)	1
Income Statement Impact of Derivative Activity [Abstract]
Total amounts presented in the statements of income in which the effects of hedges are recorded	[3]	3,503	4,364	3,785
Gain (loss) on derivative instruments not designated as hedging instruments		214	107	211
Derivative, Credit Risk Related Contingent Features [Abstract]
Aggregate fair value of derivatives containing material adverse change provisions in a net liability position		1	1
Fair value of collateral already posted		0	0
Additional collateral required to be posted if credit risk contingent features triggered		1	0
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[4]	194	138
CERC Corp [Member] | Energy Marketers [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[4]	16	24
CERC Corp [Member] | Retail End Users [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[4],[5]	178	114
CERC Corp [Member] | External Credit Rating, Investment Grade [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[6]	31	41
CERC Corp [Member] | External Credit Rating, Investment Grade [Member] | Energy Marketers [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[6]	4	11
CERC Corp [Member] | External Credit Rating, Investment Grade [Member] | Retail End Users [Member]
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Total credit risk of counterparties	[5],[6]	27	30
CERC Corp [Member] | Current Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Asset	[2]	136	100
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item		(13)	1
Gross Amounts Recognized	[1]	224	166
Gross Amounts Offset		(88)	(66)
CERC Corp [Member] | Other Noncurrent Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Asset	[2]	58	38
Gross Amounts Recognized	[1]	68	54
Gross Amounts Offset		(10)	(16)
CERC Corp [Member] | Current Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Gross Amounts Recognized	[1]	(180)	(183)
Gross Amounts Offset		136	81
Derivative Liability	[2]	(44)	(102)
CERC Corp [Member] | Other Noncurrent Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Gross Amounts Recognized	[1]	(39)	(25)
Gross Amounts Offset		25	20
Derivative Liability	[2]	(14)	(5)
CERC Corp [Member] | Not Designated as Hedging Instrument [Member] | Current Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[10],[11],[12]	139	103
Derivative Liabilities Fair Value	[10],[11],[12]	3	3
CERC Corp [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[10],[11],[12]	58	38
Derivative Liabilities Fair Value	[10],[11],[12]	0	0
CERC Corp [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[10],[11],[12]	73	62
Derivative Liabilities Fair Value	[10],[11],[12]	177	173
CERC Corp [Member] | Not Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[10],[11],[12]	10	16
Derivative Liabilities Fair Value	[10],[11],[12]	$ 39	$ 25
CERC Corp [Member] | Long [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative gross volume notional amount (in Bcf) | Bcf		374	140
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Current Liabilities [Member] | Interest Rate Contract [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value		$ 0	$ 0
Derivative Liabilities Fair Value		0	24
Cash Flow Hedging [Member] | Houston Electric [Member] | Designated as Hedging Instrument [Member] | Current Liabilities [Member] | Interest Rate Contract [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value		0	0
Derivative Liabilities Fair Value		0	24
Fair Value Hedging [Member] | Current Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Asset		47	57
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Current Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[7],[8],[9]	12	1
Derivative Liabilities Fair Value	[7],[8],[9]	0	7
Fair Value Hedging [Member] | CERC Corp [Member] | Current Assets [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Asset		47	57
Fair Value Hedging [Member] | CERC Corp [Member] | Designated as Hedging Instrument [Member] | Current Liabilities [Member] | Energy Related Derivative [Member]
Derivative Assets (Liabilities), at Fair Value, Net, by Balance Sheet Classification [Abstract]
Derivative Assets Fair Value	[10],[11],[12]	12	1
Derivative Liabilities Fair Value	[10],[11],[12]	0	7
Gains (Losses) in Revenue [Member] | CERC Corp [Member] | Energy Related Derivative [Member]
Income Statement Impact of Derivative Activity [Abstract]
Gain (loss) on derivative instruments not designated as hedging instruments		214	107	211
Natural Gas Expenses [Member] | Fair Value Hedging [Member] | Energy Related Derivative [Member]
Income Statement Impact of Derivative Activity [Abstract]
Change in unrealized gain (loss) on fair value hedging instruments	[3]	(14)	(13)	14
Amounts excluded from effectiveness testing recognized in earnings immediately	[3]	(213)	(149)	(67)
Natural Gas Expenses [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member]
Income Statement Impact of Derivative Activity [Abstract]
Change in unrealized gain (loss) on fair value hedging instruments	[3]	14	13	(14)
Natural Gas Expenses [Member] | Fair Value Hedging [Member] | CERC Corp [Member] | Energy Related Derivative [Member]
Income Statement Impact of Derivative Activity [Abstract]
Change in unrealized gain (loss) on fair value hedging instruments	[13]	(14)	(13)	14
Amounts excluded from effectiveness testing recognized in earnings immediately	[13]	(213)	(149)	(67)
Natural Gas Expenses [Member] | Fair Value Hedging [Member] | CERC Corp [Member] | Designated as Hedging Instrument [Member] | Energy Related Derivative [Member]
Income Statement Impact of Derivative Activity [Abstract]
Change in unrealized gain (loss) on fair value hedging instruments	[13]	14	13	(14)
Gains (Losses) in Other Income (Expense) [Member] | Interest Rate Contract [Member]
Income Statement Impact of Derivative Activity [Abstract]
Gain (loss) on derivative instruments not designated as hedging instruments		0	2	0
Gains (Losses) in Other Income (Expense) [Member] | IDS Derivative [Member]
Income Statement Impact of Derivative Activity [Abstract]
Gain (loss) on derivative instruments not designated as hedging instruments		$ (292)	$ (232)	$ 49
[1]	Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements.
[2]	The derivative assets and liabilities on the Registrant’s respective Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.
[3]	Income statement impact associated with cash flow hedge activity is related to gains and losses reclassified from Accumulated other comprehensive income into income. Amounts are immaterial for the years ended December 31, 2019 , 2018 and 2017 , respectively.
[4]	The amounts reflected in the table above were not impacted by collateral netting.
[5]	End users are comprised primarily of customers who have contracted to fix the price of a portion of their physical gas requirements for future periods.
[6]	“Investment grade” is primarily determined using publicly available credit ratings and considers credit support (including parent company guarantees) and collateral (including cash and standby letters of credit). For unrated counterparties, CERC determines a synthetic credit rating by performing financial statement analysis and consider contractual rights and restrictions and collateral.
[7]	Derivative Assets and Derivative Liabilities include no material amounts related to physical forward transactions with Enable.
[8]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 2,226 Bcf or a net 374 Bcf long position and 1,674 Bcf or a net 140 Bcf long position as of December 31, 2019 and 2018 , respectively. Certain natural gas contracts hedge basis risk only and lack a fixed price exposure.
[9]	Natural gas contracts are presented on a net basis in CenterPoint Energy’s Consolidated Balance Sheets as they are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within CenterPoint Energy’s Consolidated Balance Sheets. The net of total non-trading natural gas derivative assets and liabilities is detailed in the Offsetting of Natural Gas Derivative Assets and Liabilities table below
[10]	Derivative Assets and Derivative Liabilities include no material amounts related to physical forward transactions with Enable.
[11]	Natural gas contracts are presented on a net basis in CERC’s Consolidated Balance Sheets as they are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within CERC’s Consolidated Balance Sheets. The net of total non-trading natural gas derivative assets and liabilities is detailed in the Offsetting of Natural Gas Derivative Assets and Liabilities table below.
[12]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 2,226 Bcf or a net 374 Bcf long position and 1,674 Bcf or a net 140 Bcf long position as of December 31, 2019 and 2018 , respectively. Certain natural gas contracts hedge basis risk only and lack a fixed price exposure.
[13]	Income statement impact associated with cash flow hedge activity is related to gains and losses reclassified from Accumulated other comprehensive income into income. Amounts are immaterial for the years ended December 31, 2019 , 2018 and 2017 , respectively.

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ in Millions		12 Months Ended
		Dec. 31, 2019USD ($)		Dec. 31, 2018USD ($)		Dec. 31, 2017USD ($)
Assets
Natural gas derivatives (3)(4)		$ 47		$ 57
Total derivative assets, netting adjustment	[1]	(98)		(82)
Total assets		1,068		747
Liabilities
Total derivative liabilities, netting adjustment	[1]	(161)		(101)
Total liabilities		996		732
Fair value measurement using significant unobservable input (level 3) reconciliation [Roll Forward]
Beginning balance		30	[2]	(622)	[2]	$ (704)
Total gains		17		30		96
Total settlements		(22)		(39)		(11)
Transfers into Level 3		(1)		5		14
Transfers out of Level 3 (1)	[3]	(6)		656		(17)
Ending balance (2)	[2]	18		30		(622)
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date (3)		12		18		87
Estimated Fair Value of Financial Instruments
Goodwill impairment		48		0		0
Carrying amount [Member]
Estimated Fair Value of Financial Instruments
Long-term debt, including current maturities	[4]	15,093		9,140
Fair value [Member]
Estimated Fair Value of Financial Instruments
Long-term debt, including current maturities	[4]	16,067		9,308
Natural gas [Member]
Liabilities
Derivative fair value offsets, net		63		19
Fair Value, Inputs, Level 1 [Member]
Assets
Total assets		874		609
Liabilities
Total liabilities		13		24
Fair Value, Inputs, Level 2 [Member]
Assets
Total assets		250		173
Liabilities
Total liabilities		1,120		792
Fair Value, Inputs, Level 3 [Member]
Assets
Total assets		42		47
Liabilities
Total liabilities		$ 24		17
Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Minimum [Member]
Fair Value, assets and liabilities measured on recurring basis, financial statement captions
Fair value inputs (price per MMBtu)		1.44
Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Maximum [Member]
Fair Value, assets and liabilities measured on recurring basis, financial statement captions
Fair value inputs (price per MMBtu)		5.20
Fair Value, Measurements, Recurring [Member]
Assets
Corporate equities		$ 825		542
Investments, including money market funds (2)	[5]	49		66
Fair Value, Measurements, Recurring [Member] | Natural gas [Member]
Assets
Natural gas derivative netting adjustment	[1],[6]	(98)		(82)
Natural gas derivatives (3)(4)	[6]	194		138
Liabilities
Derivative liabilities, netting adjustment	[1],[6]	(161)		(101)
Derivative liabilities	[6]	80		107
Fair Value, Measurements, Recurring [Member] | IDS Derivative [Member]
Liabilities
Derivative liabilities, netting adjustment		0		0
Derivative liabilities		893		601
Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		10		24
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Corporate equities		825		542
Investments, including money market funds (2)	[5]	49		66
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Natural gas [Member]
Assets
Natural gas derivatives (3)(4)	[6],[7]	0		0
Liabilities
Derivative liabilities	[6],[7]	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | IDS Derivative [Member]
Liabilities
Derivative liabilities		0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		0		24
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Corporate equities		0		0
Investments, including money market funds (2)	[5]	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Natural gas [Member]
Assets
Natural gas derivatives (3)(4)	[6]	250		173
Liabilities
Derivative liabilities	[6]	217		191
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | IDS Derivative [Member]
Liabilities
Derivative liabilities		893		601
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		10		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Corporate equities		0		0
Investments, including money market funds (2)	[5]	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Natural gas [Member]
Assets
Natural gas derivatives (3)(4)	[6]	42		47
Liabilities
Derivative liabilities	[6]	24		17
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | IDS Derivative [Member]
Liabilities
Derivative liabilities		0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		0		0
Houston Electric [Member]
Assets
Total derivative assets, netting adjustment		0		0
Total assets		32		48
Liabilities
Total derivative liabilities, netting adjustment		0		0
Total liabilities		0		24
Houston Electric [Member] | Carrying amount [Member]
Estimated Fair Value of Financial Instruments
Long-term debt, including current maturities	[4]	4,950		4,717
Houston Electric [Member] | Fair value [Member]
Estimated Fair Value of Financial Instruments
Long-term debt, including current maturities	[4]	5,457		4,770
Houston Electric [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Total assets		32		48
Liabilities
Total liabilities		0		24
Houston Electric [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Total assets		0		0
Liabilities
Total liabilities		0		0
Houston Electric [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Total assets		0		0
Liabilities
Total liabilities		0		0
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Investments, including money market funds (2)	[5]	32		48
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		0		24
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Investments, including money market funds (2)	[5]	32		48
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		0		24
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Investments, including money market funds (2)	[5]	0		0
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		0		0
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Investments, including money market funds (2)	[5]	0		0
Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Contract [Member]
Liabilities
Derivative liabilities		0		0
CERC Corp [Member]
Assets
Natural gas derivatives (3)(4)		47		57
Total derivative assets, netting adjustment	[1]	(98)		(82)
Total assets		207		152
Liabilities
Total derivative liabilities, netting adjustment	[1]	(161)		(101)
Total liabilities		71		107
Fair value measurement using significant unobservable input (level 3) reconciliation [Roll Forward]
Beginning balance		30	[2]	46	[2]	13
Total gains		17		30		47
Total settlements		(22)		(39)		(11)
Transfers into Level 3		(1)		5		14
Transfers out of Level 3 (1)	[3]	(6)		(12)		(17)
Ending balance (2)	[2]	18		30		46
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date (3)		12		18		38
Estimated Fair Value of Financial Instruments
Goodwill impairment		48		0		$ 0
CERC Corp [Member] | Carrying amount [Member]
Estimated Fair Value of Financial Instruments
Long-term debt, including current maturities		2,546		2,371
CERC Corp [Member] | Fair value [Member]
Estimated Fair Value of Financial Instruments
Long-term debt, including current maturities		2,803		2,488
CERC Corp [Member] | Natural gas [Member]
Liabilities
Derivative fair value offsets, net		63		19
CERC Corp [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Total assets		13		14
Liabilities
Total liabilities		13		0
CERC Corp [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Total assets		250		173
Liabilities
Total liabilities		195		191
CERC Corp [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Total assets		42		47
Liabilities
Total liabilities		$ 24		17
CERC Corp [Member] | Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Minimum [Member]
Fair Value, assets and liabilities measured on recurring basis, financial statement captions
Fair value inputs (price per MMBtu)		1.44
CERC Corp [Member] | Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Maximum [Member]
Fair Value, assets and liabilities measured on recurring basis, financial statement captions
Fair value inputs (price per MMBtu)		5.20
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Corporate equities		$ 2		2
Investments, including money market funds (2)	[5]	11		11
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Natural gas [Member]
Assets
Natural gas derivative netting adjustment	[1],[6]	(98)		(82)
Natural gas derivatives (3)(4)	[6]	194		138
Liabilities
Derivative liabilities, netting adjustment	[1],[6]	(161)		(101)
Derivative liabilities	[6]	58		107
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Corporate equities		2		2
Investments, including money market funds (2)	[5]	11		11
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Natural gas [Member]
Assets
Natural gas derivatives (3)(4)	[6],[7]	0		0
Liabilities
Derivative liabilities	[6],[7]	0		0
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Corporate equities		0		0
Investments, including money market funds (2)	[5]	0		0
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Natural gas [Member]
Assets
Natural gas derivatives (3)(4)	[6]	250		173
Liabilities
Derivative liabilities	[6]	195		191
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Corporate equities		0		0
Investments, including money market funds (2)	[5]	0		0
CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Natural gas [Member]
Assets
Natural gas derivatives (3)(4)	[6]	42		47
Liabilities
Derivative liabilities	[6]	24		17
Natural gas inventory [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Hedged portion of natural gas inventory		0		1
Liabilities
Fair Value Hedge Liabilities		13		0
Natural gas inventory [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Hedged portion of natural gas inventory		0		1
Liabilities
Fair Value Hedge Liabilities		13		0
Natural gas inventory [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Hedged portion of natural gas inventory		0		0
Liabilities
Fair Value Hedge Liabilities		0		0
Natural gas inventory [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Hedged portion of natural gas inventory		0		0
Liabilities
Fair Value Hedge Liabilities		0		0
Natural gas inventory [Member] | CERC Corp [Member] | Fair Value, Measurements, Recurring [Member]
Assets
Hedged portion of natural gas inventory		0		1
Liabilities
Fair Value Hedge Liabilities		13		0
Natural gas inventory [Member] | CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Hedged portion of natural gas inventory		0		1
Liabilities
Fair Value Hedge Liabilities		13		0
Natural gas inventory [Member] | CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Hedged portion of natural gas inventory		0		0
Liabilities
Fair Value Hedge Liabilities		0		0
Natural gas inventory [Member] | CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Hedged portion of natural gas inventory		0		0
Liabilities
Fair Value Hedge Liabilities		0		$ 0
Energy Services [Member]
Estimated Fair Value of Financial Instruments
Goodwill impairment		48
Energy Services [Member] | CERC Corp [Member]
Estimated Fair Value of Financial Instruments
Goodwill impairment		$ 48
[1]	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy and CERC to settle positive and negative positions and also include cash collateral posted with the same counterparties as follows: December 31, 2019 December 31, 2018 CenterPoint Energy CERC CenterPoint Energy CERC (in millions) Cash collateral posted with the same counterparties $ 63 $ 63 $ 19 $ 19
[2]	CenterPoint Energy and CERC did not have significant Level 3 purchases or sales during any of the years ended December 31, 2019 , 2018 or 2017.
[3]	During 2018, CenterPoint Energy transferred its indexed debt securities derivative from Level 3 to Level 2 to reflect changes in the significance of the unobservable inputs used in the valuation.
[4]	Includes Securitization Bond debt.
[5]	Amounts are included in Prepaid and Other Current Assets and Other Assets in the Consolidated Balance Sheets.
[6]	Natural gas derivatives include no material amounts related to physical forward transactions with Enable.
[7]	Level 1 natural gas derivatives include exchange-traded derivatives cleared by the CME, which deems that financial instruments cleared by the CME are settled daily in connection with posted cash payments. As a result of this exchange rule, CME-related derivatives are considered to have no fair value at the balance sheet date for financial reporting purposes, and are presented in Level 1 net of posted cash; however, the derivatives remain outstanding and subject to future commodity price fluctuations until they are settled in accordance with their contractual terms. Derivative transactions cleared on exchanges other than the CME (e.g., the Intercontinental Exchange or ICE) continue to be reported on a gross basis.

Unconsolidated Affiliate (Cen_3

Unconsolidated Affiliate (CenterPoint Energy and CERC) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Enable Units [Abstract]
Preferred units - unconsolidated affiliate		$ 363								$ 363		$ 363
Percentage of sales that trigger right of first refusal										5.00%
Enable Distributions [Abstract]
Proceeds from Equity Method Investment, Distribution										$ 261		267	$ 0
Total distributions received from Enable										339		333	333
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Goodwill impairment										48		0	0
CenterPoint Energy’s equity in earnings, net										230		307	265
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]
CenterPoint Energy’s equity method investment in Enable		2,482								2,408		2,482
CERC Corp [Member]
Contribution from parent										129		960	38
Enable Distributions [Abstract]
Total distributions received from Enable												223	297
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Goodwill impairment										48		0	0
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Income tax expense										0		46	104
Income (loss) from discontinued operations, net of tax		(2)	[1]	$ 44		$ 44		$ 52		$ 0		138	161
Enable Midstream Partners [Member]
Share Price										$ 10.03
OGE [Member]
Enable Units [Abstract]
Percentage of sales that trigger right of first refusal										5.00%
Non-utility Investments [Member]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]
CenterPoint Energy’s equity method investment in Enable	[2]									$ 2
Proliance Holdings LLC [Member]
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
CenterPoint Energy’s equity in earnings, net										1		0	0
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]
CenterPoint Energy’s equity method investment in Enable		$ 0										$ 0
Enable Midstream Partners [Member]
Equity Method Investment Decrease in Carrying Value										$ 61
Equity Method Investment Carrying Value Per Unit										$ 10.29
Enable Partnership Interest [Abstract]
Limited partner ownership interest	[3],[4]	54.00%								53.70%		54.00%
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Operating revenues										$ 2,960		$ 3,431	2,803
Cost of sales, excluding depreciation and amortization										1,279		1,819	1,381
Depreciation and amortization										433		398	366
Operating income										569		648	528
Goodwill impairment										86
Net income attributable to Enable common units										360		485	400
CenterPoint Energy’s interest										193		262	216
Basis difference amortization (1)	[5]									47		47	49
Loss on dilution, net of proportional basis difference recognition										(11)		(2)	0
CenterPoint Energy’s equity in earnings, net	[6],[7]									229		307	$ 265
Equity Method Investment, Summarized Financial Information [Abstract]
Current assets		$ 449								389		449
Non-current assets		11,995								11,877		11,995
Current liabilities		1,615								780		1,615
Non-current liabilities		3,211								4,077		3,211
Non-controlling interest		38								37		38
Preferred equity		362								362		362
Equity Method Investment Summarized Financial Information Accumulated Other Comprehensive Income Loss										(3)
Enable partners’ equity		7,218								7,013		7,218
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract]
CenterPoint Energy’s ownership interest in Enable partners’ equity		3,896								3,767		3,896
CenterPoint Energy’s basis difference		(1,414)								(1,361)		(1,414)
CenterPoint Energy’s equity method investment in Enable		$ 2,482								$ 2,406		$ 2,482
Enable Midstream Partners [Member] | Common Units [Member]
Enable Distributions [Abstract]
Distribution per share of common units										$ 1.2970		$ 1.2720	$ 1.2720
Proceeds from Equity Method Investment, Distribution										$ 303	[8]	$ 297	$ 297
Enable Midstream Partners [Member] | Series A Preferred Units [Member]
Enable Distributions [Abstract]
Distribution per share of Series A preferred units										$ 2.5000		$ 2.5000	$ 2.5000
Distributions received from Enable cost method investment										$ 36		$ 36	$ 36
Enable Midstream Partners [Member] | CERC Corp [Member] | Common Units [Member]
Enable Distributions [Abstract]
Distribution per share of common units	[8]											$ 0.9540	$ 1.2720
Proceeds from Equity Method Investment, Distribution	[8]											$ 223	$ 297
Common Units [Member] | Enable Midstream Partners [Member]
Enable Units [Abstract]
Limited partner interest units held	[4]	233,856,623								233,856,623		233,856,623
Series A Preferred Units [Member] | Enable Midstream Partners [Member]
Enable Units [Abstract]
Preferred units held	[4],[9]	14,520,000								14,520,000		14,520,000
Natural Gas Expenses [Member] | Enable Midstream Partners [Member]
Transaction with Enable [Abstract]
Natural gas expenses, including transportation and storage costs (1)	[10]									$ 120		$ 122	115
Accounts payable for natural gas purchases from Enable		$ 11								11		11
Natural Gas Expenses [Member] | Enable Midstream Partners [Member] | CERC Corp [Member]
Transaction with Enable [Abstract]
Natural gas expenses, including transportation and storage costs (1)	[10]									120		122	115
Accounts payable for natural gas purchases from Enable		11								11		11
Transitional Service [Member] | Enable Midstream Partners [Member]
Transaction with Enable [Abstract]
Reimbursement of support services (2)	[7]									0		4	4
Accounts receivable for amounts billed for services provided to Enable		2								2		2
Transitional Service [Member] | Enable Midstream Partners [Member] | CERC Corp [Member]
Transaction with Enable [Abstract]
Reimbursement of support services (2)	[7]									0		4	4
Accounts receivable for amounts billed for services provided to Enable		$ 2								$ 2		$ 2
Enable Midstream Partners [Member]
Enable Partnership Interest [Abstract]
Limited partner ownership interest	[3]									100.00%		100.00%
Enable Units [Abstract]
Maximum incentive distribution right										50.00%
Enable Midstream Partners [Member] | OGE [Member]
Enable Partnership Interest [Abstract]
Limited partner ownership interest	[3]									25.50%		25.60%
Enable Midstream Partners [Member] | Public unitholders [Member]
Enable Partnership Interest [Abstract]
Limited partner ownership interest	[3]									20.80%		20.40%
Enable Midstream Partners [Member] | Minimum [Member]
Enable Units [Abstract]
Incentive distribution per unit										$ 0.2875
Enable Midstream Partners [Member] | Maximum [Member]
Enable Units [Abstract]
Incentive distribution per unit										$ 0.330625
Enable Midstream Partners [Member] | Common Units [Member]
Enable Units [Abstract]
Limited partner interest units held		433,232,411								435,201,365		433,232,411
Enable Midstream Partners [Member] | Common Units [Member] | OGE [Member]
Enable Units [Abstract]
Limited partner interest units held		110,982,805								110,982,805		110,982,805
Enable Midstream Partners [Member] | Common Units [Member] | Public unitholders [Member]
Enable Units [Abstract]
Limited partner interest units held		88,392,983								90,361,937		88,392,983
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | Enable Midstream Partners [Member] | CERC Corp [Member]
Investment in unconsolidated affiliates - discontinued operations	[11]												2,472
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax												$ 184	265
Income tax expense												46	104
Income (loss) from discontinued operations, net of tax												$ 138	$ 161
Enable GP, LLC [Member]
Enable Units [Abstract]
Management rights ownership percentage										50.00%
Incentive distribution right										40.00%
Enable GP, LLC [Member] | CenterPoint Energy [Member]
Enable Units [Abstract]
Management rights ownership percentage	[12],[13]									50.00%
Incentive distribution right	[13],[14]									40.00%
Enable GP, LLC [Member] | OGE [Member]
Enable Units [Abstract]
Management rights ownership percentage	[12]									50.00%
Incentive distribution right	[14]									60.00%
[1]	Amounts have been recast to reflect discontinued operations in all periods presented.
[2]	Represents the fair value of non-utility equity investments acquired in the Merger.
[3]	Excludes the Enable Series A Preferred Units owned by CenterPoint Energy.
[4]	Prior to the Internal Spin completed in September 2018, CenterPoint Energy’s investment in Enable’s common units, excluding the Enable Series A Preferred Units held directly by CenterPoint Energy, was held indirectly through CERC.
[5]	Equity in earnings of unconsolidated affiliate includes CenterPoint Energy’s share of Enable earnings adjusted for the amortization of the basis difference of CenterPoint Energy’s original investment in Enable and its underlying equity in net assets of Enable. The basis difference is being amortized through the year 2048.
[6]	Equity earnings for the year ended December 31, 2019 includes CenterPoint Energy’s share of Enable’s $86 million goodwill impairment recorded in the fourth quarter of 2019.
[7]	Represents amounts billed for certain support services provided to Enable. Actual support services costs are recorded net of reimbursement.
[8]	Prior to the Internal Spin completed in September 2018, distributions from Enable were received by CERC. After such date, distributions from Enable were received directly by CenterPoint Energy (through CNP Midstream).
[9]	The carrying amount of the Enable Series A Preferred Units, reflected as Preferred units - unconsolidated affiliate on CenterPoint Energy’s Consolidated Balance Sheets, was $363 million as of both December 31, 2019 and 2018 . No impairment charges or adjustment to carrying value were made as no observable price changes were identified in the current or prior reporting periods.
[10]	Included in Non-utility costs of revenues, including natural gas on CenterPoint Energy’s and CERC’s respective Statements of Consolidated Income.
[11]	On September 4, 2018, CERC completed the Internal Spin. For further information regarding the Internal Spin, see Note 11 .
[12]	As of December 31, 2019 , Enable is controlled jointly by CenterPoint Energy and OGE. Sale of CenterPoint Energy’s or OGE’s ownership interests in Enable GP to a third party is subject to mutual rights of first offer and first refusal, and CenterPoint Energy is not permitted to dispose of less than all of its interest in Enable GP.
[13]	Held indirectly through CNP Midstream.
[14]	Enable is expected to pay a minimum quarterly distribution of $0.2875 per common unit on its outstanding common units to the extent it has sufficient cash from operations after establishment of cash reserves and payment of fees and expenses, including payments to Enable GP and its affiliates, within 60 days after the end of each quarter. If cash distributions to Enable’s unitholders exceed $0.330625 per common unit in any quarter, Enable GP will receive increasing percentages or incentive distributions rights, up to 50% , of the cash Enable distributes in excess of that amount. In certain circumstances Enable GP will have the right to reset the minimum quarterly distribution and the target distribution levels at which the incentive distributions receive increasing percentages to higher levels based on Enable’s cash distributions at the time of the exercise of this reset election. To date, no incentive distributions have been made.

Indexed Debt Securities (ZENS_3

Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
ZENS-Related Securities
ZENS-Related Securities	$ 540,000,000
Proceeds from sale and maturity of marketable securities	0	$ (398,000,000)	$ 0
Gain (loss) on ZENS-Related Securities	282,000,000	(22,000,000)	7,000,000
ZENS-Related Securities	822,000,000	540,000,000
Debt component of ZENS
Debt Component of ZENS	24,000,000
Distribution to ZENS holders	0	(398,000,000)	0
Debt Component of ZENS	19,000,000	24,000,000
Derivative component of ZENS
Derivative Component of ZENS	601,000,000
Distribution to ZENS holders	0	(398,000,000)	0
Loss (gain) on indexed debt securities	292,000,000	232,000,000	(49,000,000)
Derivative Component of ZENS	$ 893,000,000	$ 601,000,000
AT&T Common [Member]
Indexed Debt Securities [Line Items]
Balance of investment owned (in shares)	10,212,945	10,212,945
Charter Common [Member]
Indexed Debt Securities [Line Items]
Balance of investment owned (in shares)	872,503	872,912
ZENS-Related Securities [Member]
ZENS-Related Securities
ZENS-Related Securities	$ 540,000,000	$ 960,000,000	953,000,000
Proceeds from sale and maturity of marketable securities		(398,000,000)
Gain (loss) on ZENS-Related Securities	282,000,000	(22,000,000)	7,000,000
ZENS-Related Securities	822,000,000	540,000,000	960,000,000
Debt Component Of ZENS [Member]
Debt component of ZENS
Debt Component of ZENS	24,000,000	122,000,000	114,000,000
Accretion of debt component of ZENS	17,000,000	21,000,000	27,000,000
2 % interest paid	(17,000,000)	(17,000,000)	(17,000,000)
Distribution to ZENS holders	(5,000,000)	(102,000,000)	(2,000,000)
Debt Component of ZENS	19,000,000	24,000,000	122,000,000
Derivative component of ZENS
Distribution to ZENS holders	(5,000,000)	(102,000,000)	(2,000,000)
Derivative Component Of ZENS [Member]
Debt component of ZENS
Distribution to ZENS holders	0	(46,000,000)	0
Derivative component of ZENS
Derivative Component of ZENS	601,000,000	668,000,000	717,000,000
Distribution to ZENS holders	0	(46,000,000)	0
Loss (gain) on indexed debt securities	292,000,000	(21,000,000)	(49,000,000)
Derivative Component of ZENS	893,000,000	$ 601,000,000	$ 668,000,000
Subordinated Debt ZENS Member
Indexed Debt Securities [Line Items]
Principal amount of debt issued	1,000,000,000
Outstanding debt balance	$ 828,000,000
Subordinated note cash exchangeable percentage of fair value	95.00%
ZENS annual interest rate	2.00%
Target annual yield on referenced shares before increase or decrease of principal amount of subordinated note	2.309%
Contingent principal amount of indexed debt securities issued by CenterPoint Energy in September 1999 and outstanding and exchangeable	$ 75,000,000
The cash exchange amount from referenced shares per $1,000 face amount of individual notes	944
Face amount of each indexed debt security notes issued by CenterPoint Energy in September 1999	$ 1,000
Subordinated Debt ZENS Member | AT&T Common [Member]
Indexed Debt Securities [Line Items]
Number of shares referenced in exchangeable subordinated note	0.7185	0.7185
Subordinated Debt ZENS Member | Charter Common [Member]
Indexed Debt Securities [Line Items]
Number of shares referenced in exchangeable subordinated note	0.061382	0.061382

Equity (CenterPoint Energy) (De

Equity (CenterPoint Energy) (Details)		Oct. 17, 2019USD ($)$ / shares	Jul. 31, 2019USD ($)$ / shares	Apr. 25, 2019USD ($)$ / shares	Dec. 12, 2018USD ($)$ / shares	Oct. 23, 2018USD ($)$ / shares	Oct. 01, 2018USD ($)$ / sharesshares	Aug. 22, 2018USD ($)$ / sharesshares	Jul. 26, 2018USD ($)$ / shares	Apr. 26, 2018USD ($)$ / shares	Dec. 13, 2017USD ($)$ / shares	Oct. 25, 2017USD ($)$ / shares	Jul. 27, 2017USD ($)$ / shares	Apr. 27, 2017USD ($)$ / shares	Jan. 05, 2017USD ($)$ / shares	Dec. 31, 2019USD ($)day$ / sharesshares	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)$ / shares
Dividends declared per share | $ / shares																$ 0.86	$ 1.1200	$ 1.35
Preferred stock dividend requirement																$ 117,000,000	$ 35,000,000	$ 0
Preferred stock par value (in dollars per share) | $ / shares																$ 0.01	$ 0.01	$ 0.01
Proceeds from the issuance of Series A Preferred Stock, net								$ 790,000,000								$ 0	$ 1,740,000,000	$ 0
Proceeds from issuance of common stock																0	1,844,000,000	0
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance																(108,000,000)	(68,000,000)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax																1,000,000	0	0
Other comprehensive loss from unconsolidated affiliates, net of tax																(1,000,000)	0	0
Prior service cost (2)	[1]															1,000,000	1,000,000
Actuarial losses (2)	[1]															8,000,000	6,000,000
Tax benefit (expense)																(3,000,000)	6,000,000
Net current period other comprehensive income (loss)																10,000,000	(25,000,000)	3,000,000
Ending Balance																(98,000,000)	(108,000,000)	$ (68,000,000)
Enable Midstream Partners [Member]
Undistributed earnings from equity method investments included in retained earnings																$ 0	$ 31,000,000
Common Stock [Member]
Declaration Date		Oct. 17, 2019	Jul. 31, 2019	Apr. 25, 2019	Dec. 12, 2018	Oct. 23, 2018			Jul. 26, 2018	Apr. 26, 2018	Dec. 13, 2017	Oct. 25, 2017	Jul. 27, 2017	Apr. 27, 2017	Jan. 5, 2017
Record Date		Nov. 21, 2019	Aug. 15, 2019	May 16, 2019	Feb. 21, 2019	Nov. 15, 2018			Aug. 16, 2018	May 17, 2018	Feb. 15, 2018	Nov. 16, 2017	Aug. 16, 2017	May 16, 2017	Feb. 16, 2017
Payment Date		Dec. 12, 2019	Sep. 12, 2019	Jun. 13, 2019	Mar. 14, 2019	Dec. 13, 2018			Sep. 13, 2018	Jun. 14, 2018	Mar. 8, 2018	Dec. 8, 2017	Sep. 8, 2017	Jun. 9, 2017	Mar. 10, 2017
Dividends declared per share | $ / shares		$ 0.2875	$ 0.2875	$ 0.2875	$ 0.2875	$ 0.2775			$ 0.2775	$ 0.2775	$ 0.2775	$ 0.2675	$ 0.2675	$ 0.2675	$ 0.2675	$ 0.8625	$ 1.1200	$ 1.3475
Dividends declared		$ 144,000,000	$ 145,000,000	$ 144,000,000	$ 144,000,000	$ 139,000,000			$ 120,000,000	$ 120,000,000	$ 120,000,000	$ 116,000,000	$ 115,000,000	$ 115,000,000	$ 115,000,000	$ 433,000,000	$ 523,000,000	$ 581,000,000
Stock issued (in shares) | shares							69,633,027
Common stock issued per share price | $ / shares							$ 27.25
Proceeds from issuance of common stock							$ 1,844,000,000
Series A Preferred Stock [Member]
Declaration Date			Jul. 31, 2019		Dec. 12, 2018
Record Date			Aug. 15, 2019		Feb. 15, 2019
Payment Date			Sep. 3, 2019		Mar. 1, 2019
Dividends declared per share | $ / shares			$ 30.6250		$ 32.1563											$ 30.6250	$ 32.1563	$ 0
Dividends declared			$ 24,000,000		$ 26,000,000											$ 24,000,000	$ 26,000,000
Preferred stock dividend requirement																$ 49,000,000	$ 18,000,000	$ 0
Stock issued (in shares) | shares								800,000
Preferred stock par value (in dollars per share) | $ / shares								$ 1,000								$ 0.01	$ 0.01
Preferred stock liquidation preference																$ 800,000,000	$ 800,000,000
Preferred stock liquidation preference (per share) | $ / shares																$ 1,000
Preferred stock dividend rate																6.125%
Preferred stock redemption price (per share) | $ / shares																$ 1,000
Preferred stock convertible threshold (in days) | day																120
Series B Preferred Stock [Member]
Declaration Date		Oct. 17, 2019	Jul. 31, 2019	Apr. 25, 2019	Dec. 12, 2018	Oct. 23, 2018
Record Date		Nov. 15, 2019	Aug. 15, 2019	May 15, 2019	Feb. 15, 2019	Nov. 15, 2018
Payment Date		Dec. 2, 2019	Sep. 3, 2019	Jun. 3, 2019	Mar. 1, 2019	Dec. 1, 2018
Dividends declared per share | $ / shares		$ 17.5000	$ 17.5000	$ 17.5000	$ 17.5000	$ 11.6667										$ 52.5000	$ 29.1667	$ 0
Dividends declared		$ 17,000,000	$ 17,000,000	$ 17,000,000	$ 17,000,000	$ 11,000,000										$ 51,000,000	$ 28,000,000
Preferred stock dividend requirement																$ 68,000,000	$ 17,000,000	$ 0
Preferred stock par value (in dollars per share) | $ / shares																$ 0.01	$ 0.01
Preferred stock liquidation preference																$ 977,500,000	$ 977,500,000
Preferred stock liquidation preference (per share) | $ / shares																$ 1,000
Preferred stock dividend rate																7.00%
Proceeds from the issuance of Series B Preferred Stock, net							$ 950,000,000
Depositary Share, Conversion Ratio																0.05
Preferred Stock, Convertible, Conversion Price | $ / shares																$ 1,000
Preferred stock threshold consecutive calendar days | day																20
Depositary Share [Member]
Stock issued (in shares) | shares							19,550,000
Depositary share par value (in dollars per depositary share) | $ / shares							$ 50									$ 50
Number of depositary shares eligible for conversion (in shares) | shares																20
120 Days After Conclusion of Review or Appeal [Member] | Series A Preferred Stock [Member]
Preferred stock redemption price (per share) | $ / shares																$ 1,020
Preferred stock redemption percentage liquidation value																102.00%
London Interbank Offered Rate (LIBOR) [Member] | Series A Preferred Stock [Member]
Preferred stock dividend rate																3.27%
Over-Allotment Option [Member] | Common Stock [Member]
Stock issued (in shares) | shares							9,082,568
Over-Allotment Option [Member] | Series B [Member]
Stock issued (in shares) | shares							2,550,000
Minimum [Member] | Series B Preferred Stock [Member]
Preferred Stock, Convertible, Stock Price Trigger | $ / shares																$ 27.2494
Conversion rate per share | shares																30.5820
Minimum [Member] | Series B [Member]
Preferred Stock, Convertible, Stock Price Trigger | $ / shares																$ 27.2494
Minimum [Member] | Depositary Share [Member]
Conversion rate per share | shares																1.5291
Maximum [Member] | Series B Preferred Stock [Member]
Preferred Stock, Convertible, Stock Price Trigger | $ / shares																$ 32.6990
Conversion rate per share | shares																36.6980
Maximum [Member] | Series B [Member]
Preferred Stock, Convertible, Stock Price Trigger | $ / shares																$ 32.6990
Maximum [Member] | Depositary Share [Member]
Conversion rate per share | shares																1.8349
Interest Rate Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income (loss) before reclassifications:	[2]															$ (3,000,000)	(19,000,000)
Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Gain (loss) reclassified from accumulated OCI into income																1,000,000	1,000,000
Houston Electric [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance																(14,000,000)	0
Prior service cost (2)	[1]															0	0
Actuarial losses (2)	[1]															0	0
Tax benefit (expense)																0	4,000,000
Net current period other comprehensive income (loss)																(1,000,000)	(14,000,000)	(1,000,000)
Ending Balance																(15,000,000)	(14,000,000)	0
Houston Electric [Member] | Interest Rate Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income (loss) before reclassifications:	[2]															(1,000,000)	(18,000,000)
Houston Electric [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Gain (loss) reclassified from accumulated OCI into income																1,000,000	1,000,000
CERC Corp [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance																5,000,000	6,000,000
Prior service cost (2)	[1]															0	1,000,000
Actuarial losses (2)	[1]															0	0
Tax benefit (expense)																(2,000,000)	(1,000,000)
Net current period other comprehensive income (loss)																5,000,000	0	3,000,000
Ending Balance																10,000,000	5,000,000	$ 6,000,000
CERC Corp [Member] | Interest Rate Contract [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income (loss) before reclassifications:	[2]															0	(1,000,000)
CERC Corp [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Interest Expense [Member]
Gain (loss) reclassified from accumulated OCI into income																1,000,000	1,000,000
Pension and Other Postretirement Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income (loss) before reclassifications:																7,000,000	(19,000,000)
Pension and Other Postretirement Plans [Member] | Houston Electric [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income (loss) before reclassifications:																0	0
Pension and Other Postretirement Plans [Member] | CERC Corp [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income (loss) before reclassifications:																7,000,000	1,000,000
Adoption of ASU 2018-02 [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Adoption of ASU 2018-02																0	(15,000,000)
Adoption of ASU 2018-02 [Member] | Houston Electric [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Adoption of ASU 2018-02																0	0
Adoption of ASU 2018-02 [Member] | CERC Corp [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Adoption of ASU 2018-02																$ 0	$ (1,000,000)
[1]	Amounts are included in the computation of net periodic cost and are reflected in Other, net in each of the Registrants’ respective Statements of Consolidated Income.
[2]	Gains and losses are reclassified from Accumulated other comprehensive income into income when the hedged transactions affect earnings. The reclassification amounts are included in Interest and other finance charges in each of the Registrant’s respective Statements of Consolidated Income. Amounts are $1 million and less than $1 million for the years ended December 31, 2019 and 2018 , respectively.

Short Term Borrowings and Lon_3

Short Term Borrowings and Long Term Debt Schedule of Debt (Details) $ in Millions		12 Months Ended
		Dec. 31, 2019USD ($)day		Dec. 31, 2018USD ($)
Long-term debt:
Unamortized Issuance Costs		$ (22)		$ (13)
Unamortized Discount (Premium), Net		(7)		(2)
Long-term Debt		14,244		8,682
Debt, Current	[1]	868		482
Interest Expense, Related Party		5
Commercial paper issued in connection with the Merger		$ 764
Number of days until commercial paper maturity | day		60
ZENS due 2029 (2)
Long-term debt:
Long-Term	[2]	$ 0		0
Current	[1],[2]	$ 19		24
Debt instrument interest rate		2.00%
Senior notes 2.50% to 7.08% due 2020 to 2049 (3)
Long-term debt:
Long-Term		$ 3,728	[3]	2,000
Current	[1]	100	[3]	0
Variable rate term loan [Member]
Long-term debt:
Long-Term		1,000
Current	[1]	$ 500
Debt instrument interest rate		2.275%
First Mortgage Bonds [Member]
Long-term debt:
Long-Term	[4]	$ 293
Current	[1],[4]	0
Pollution control bonds 5.125% due 2028 (5)
Long-term debt:
Long-Term	[5]	68		68
Current	[1],[5]	0		0
Commercial paper (4)
Long-term debt:
Long-Term	[6]	1,901	[7]	0
Current	[1],[6],[7]	0		0
Other Debt Obligations [Member]
Long-term debt:
Long-Term		18
Current	[1]	$ 18
Parent Company [Member] | Senior notes 2.50% to 7.08% due 2020 to 2049 (3) | Minimum [Member]
Long-term debt:
Debt instrument interest rate		2.50%
Parent Company [Member] | Senior notes 2.50% to 7.08% due 2020 to 2049 (3) | Maximum [Member]
Long-term debt:
Debt instrument interest rate		7.08%
Parent Company [Member] | Variable rate term loan [Member] | Minimum [Member]
Long-term debt:
Debt instrument interest rate		2.275%
Parent Company [Member] | Variable rate term loan [Member] | Maximum [Member]
Long-term debt:
Debt instrument interest rate		2.56%
Parent Company [Member] | First Mortgage Bonds [Member] | Minimum [Member]
Long-term debt:
Debt instrument interest rate		2.19%
Parent Company [Member] | First Mortgage Bonds [Member] | Maximum [Member]
Long-term debt:
Debt instrument interest rate		6.72%
Parent Company [Member] | Pollution control bonds 5.125% due 2028 (5)
Long-term debt:
Long-Term		$ 68
Debt instrument interest rate		5.125%
Amount of debt secured by general mortgage bonds		$ 68		68
VUHI [Member]
Long-term debt:
Notes Payable, Related Parties, Noncurrent		$ 568
Number of days until commercial paper maturity | day		30
VUHI [Member] | Senior notes 3.55% to 6.625% due 2021 to 2047
Long-term debt:
Long-Term		$ 532
Houston Electric [Member]
Long-term debt:
Unamortized Issuance Costs		(27)		(24)
Unamortized Discount (Premium), Net		(15)		(11)
Long-term Debt		4,719		4,258
Debt, Current	[1]	231		458
Houston Electric [Member] | First mortgage bonds 9.15% due 2021
Long-term debt:
Long-Term		102		102
Current	[1]	$ 0		0
Debt instrument interest rate		9.15%
Amount of debt secured by general mortgage bonds		$ 102
Houston Electric [Member] | General mortgage bonds 1.85% to 6.95% due 2021 to 2048
Long-term debt:
Long-Term		3,912		3,212
Current	[1]	0		0
Amount of debt secured by general mortgage bonds		$ 4,000
Houston Electric [Member] | General mortgage bonds 1.85% to 6.95% due 2021 to 2048 | Minimum [Member]
Long-term debt:
Debt instrument interest rate		1.85%
Houston Electric [Member] | General mortgage bonds 1.85% to 6.95% due 2021 to 2048 | Maximum [Member]
Long-term debt:
Debt instrument interest rate		6.95%
Houston Electric [Member] | System restoration bonds 4.243% due 2022
Long-term debt:
Long-Term		$ 134		197
Current	[1]	$ 62		59
Debt instrument interest rate		4.243%
Houston Electric [Member] | Transition bonds 5.302% due 2019
Long-term debt:
Long-Term		$ 0		0
Current	[1]	$ 0		208
Debt instrument interest rate		5.302%
Houston Electric [Member] | Transition bonds 5.234% due 2020
Long-term debt:
Long-Term		$ 0		29
Current	[1]	$ 29		56
Debt instrument interest rate		5.234%
Houston Electric [Member] | Transition bonds 2.161% to 3.028% due 2020 to 2024
Long-term debt:
Long-Term		$ 613		753
Current	[1]	$ 140		135
Houston Electric [Member] | Transition bonds 2.161% to 3.028% due 2020 to 2024 | Minimum [Member]
Long-term debt:
Debt instrument interest rate		2.161%
Houston Electric [Member] | Transition bonds 2.161% to 3.028% due 2020 to 2024 | Maximum [Member]
Long-term debt:
Debt instrument interest rate		3.028%
CERC Corp [Member]
Long-term debt:
Unamortized Issuance Costs	[8]	$ (13)		(15)
Unamortized Discount (Premium), Net	[8]	(11)		(17)
Long-term Debt	[8]	2,546		2,371
Debt, Current	[1],[8]	0		0
CERC Corp [Member] | Commercial paper (4)
Long-term debt:
Long-Term	[6],[8]	377		210
Current	[1],[8]	0		0
CERC Corp [Member] | Senior notes 3.55% to 6.625% due 2021 to 2047
Long-term debt:
Long-Term	[8]	2,193		2,193
Current	[1],[8]	$ 0		$ 0
CERC Corp [Member] | Senior notes 3.55% to 6.625% due 2021 to 2047 | Minimum [Member]
Long-term debt:
Debt instrument interest rate		3.55%
CERC Corp [Member] | Senior notes 3.55% to 6.625% due 2021 to 2047 | Maximum [Member]
Long-term debt:
Debt instrument interest rate		6.625%
Indiana Gas [Member] | Senior notes 3.55% to 6.625% due 2021 to 2047
Long-term debt:
Long-Term		$ 96
VCC [Member]
Long-term debt:
Notes Payable, Related Parties, Noncurrent		$ 191
Vectren [Member] | Senior notes 3.55% to 6.625% due 2021 to 2047 | Minimum [Member]
Long-term debt:
Debt instrument interest rate		3.72%
Vectren [Member] | Senior notes 3.55% to 6.625% due 2021 to 2047 | Maximum [Member]
Long-term debt:
Debt instrument interest rate		7.08%
[1]	Includes amounts due or exchangeable within one year of the date noted.
[2]	CenterPoint Energy’s ZENS obligation is bifurcated into a debt component and an embedded derivative component. For additional information regarding ZENS, see Note 12(b). As ZENS are exchangeable for cash at any time at the option of the holders, these notes are classified as a current portion of long-term debt.
[3]	Includes $532 million of senior notes issued by VUHI and $96 million of senior notes issued by Indiana Gas. The senior notes have stated interest rates that range from 3.72% to 7.08% . The senior notes issued by VUHI are guaranteed by SIGECO, Indiana Gas and VEDO. In connection with the Merger, two of CenterPoint Energy’s acquired wholly-owned subsidiaries, VUHI and VCC, made offers to prepay certain outstanding guaranteed senior notes as required pursuant to certain note purchase agreements previously entered into by VUHI and VCC. In turn, VUHI and VCC borrowed $568 million and $191 million , respectively, from CenterPoint Energy to fund note redemptions of senior notes effected pursuant to these prepayment offers. To fund these prepayments and payments of approximately $5 million of accrued interest, CenterPoint Energy issued approximately $764 million of commercial paper.
[4]	The first mortgage bonds issued by SIGECO subject SIGECO’s properties to a lien under the related mortgage indenture.
[5]	$68 million and $68 million of these series of debt were secured by general mortgage bonds of Houston Electric as of December 31, 2019 and 2018 , respectively. These general mortgage bonds are not reflected in Houston Electric’s consolidated financial statements because of the contingent nature of the obligations.
[6]	Classified as long-term debt because the termination date of the facility that backstops the commercial paper is more than one year from the date noted.
[7]	Commercial paper issued by VUHI has maturities up to 30 days.
[8]	Issued by CERC Corp.

Short Term Borrowings and Lon_4

Short Term Borrowings and Long Term Debt Long-term Debt (Details)		Dec. 30, 2019USD ($)	Jan. 31, 2019USD ($)	Dec. 31, 2019USD ($)day		Aug. 12, 2019USD ($)	May 15, 2019USD ($)	Feb. 08, 2019USD ($)	[1]	Jan. 15, 2019USD ($)	Dec. 31, 2018USD ($)
Line of Credit Facility [Abstract]
Size of credit facility				$ 5,100,000,000
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Number of days until commercial paper maturity | day				60
Senior Notes due 2022 [Member]
Long-term debt:
Amount of debt retired		$ 3,000,000
Debt instrument interest rate		3.33%
Senior Notes due 2025 [Member]
Long-term debt:
Amount of debt retired		$ 6,000,000
Debt instrument interest rate		4.53%
Variable rate term loan [Member]
Long-term debt:
Debt instrument interest rate				2.275%
Principal amount of debt issued							$ 1,000,000,000	$ 25,000,000
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-Term				$ 1,000,000,000
Variable term rate loan 2 [Member]
Long-term debt:
Debt instrument interest rate				2.56%
Senior Notes Due 2030 [Member]
Long-term debt:
Debt instrument interest rate				2.95%
Senior Notes Due 2049 [Member]
Long-term debt:
Debt instrument interest rate				3.70%
Commercial paper (4)
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-Term	[2]			$ 1,901,000,000	[3]						$ 0
Pollution control bonds 5.125% due 2028 (5)
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-Term	[4]			68,000,000							68,000,000
Senior Notes due 2022 and 2025 [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Make-whole premium		$ 1,000,000
Securitization Bonds [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
2020				231,000,000
2021				211,000,000
2022				219,000,000
2023				156,000,000
2024				162,000,000
Long term Debt Excluding ZENS [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
2020	[5]			831,000,000
2021	[5]			2,761,000,000
2022	[5]			3,302,000,000
2023	[5]			713,000,000
2024	[5]			1,184,000,000
Houston Electric [Member]
Line of Credit Facility [Abstract]
Size of credit facility				300,000,000
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
2020	[5]			231,000,000
2021	[5]			613,000,000
2022	[5]			519,000,000
2023	[5]			356,000,000
2024	[5]			162,000,000
Additional first mortgage bonds and general mortgage bonds that could be issued				$ 3,700,000,000
Percentage of property additions				70.00%
Houston Electric [Member] | General Mortgage Bonds Due 2049 [Member]
Long-term debt:
Debt instrument interest rate				4.25%
Principal amount of debt issued										$ 700,000,000
Houston Electric [Member] | First mortgage bonds 9.15% due 2021
Long-term debt:
Debt instrument interest rate				9.15%
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Secured debt amount with asset liens				$ 102,000,000
Replacement fund requirements to be satisfied in 2018				295,000,000
Sinking fund requirements to be satisfied in 2018				1,600,000
Long-Term				102,000,000							102,000,000
Houston Electric [Member] | General mortgage bonds 1.85% to 6.95% due 2021 to 2048
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Secured debt amount with asset liens				4,000,000,000
Long-Term				3,912,000,000							3,212,000,000
CERC Corp [Member]
Line of Credit Facility [Abstract]
Size of credit facility				900,000,000
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
2020				0
2021				593,000,000
2022				376,000,000
2023				300,000,000
2024				0
CERC Corp [Member] | Commercial paper (4)
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-Term	[2],[6]			377,000,000							210,000,000
Revolving Credit Facility [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				0							0
Revolving Credit Facility [Member] | Houston Electric [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				0							0
Revolving Credit Facility [Member] | CERC Corp [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 0							0
Line of Credit [Member] | Houston Electric [Member]
Line of Credit Facility [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	[7]			65.00%
Ratio of indebtedness to net capital	[8]			0.502
Line of Credit [Member] | CERC Corp [Member]
Line of Credit Facility [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)				65.00%
Ratio of indebtedness to net capital	[8]			0.464
Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Houston Electric [Member]
Line of Credit Facility [Abstract]
Basis spread on LIBOR	[9]			1.125%
Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | CERC Corp [Member]
Line of Credit Facility [Abstract]
Basis spread on LIBOR	[9]			1.25%
Letter of Credit [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 7,000,000							11,000,000
Letter of Credit [Member] | Houston Electric [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				0							4,000,000
Letter of Credit [Member] | CERC Corp [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				1,000,000							1,000,000
Commercial paper (4)
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				2,278,000,000							210,000,000
Commercial paper (4) | Houston Electric [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 0							$ 0
Debt, Weighted Average Interest Rate				0.00%							0.00%
Commercial paper (4) | CERC Corp [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 377,000,000							$ 210,000,000
Debt, Weighted Average Interest Rate				1.94%							2.93%
Vectren [Member]
Line of Credit Facility [Abstract]
Long-term line of credit			90
Vectren [Member] | Commercial paper (4)
Line of Credit Facility [Abstract]
Weighted average interest rate of commercial paper issued in connection with the Merger	[10],[11]		2.88%
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit	[10],[11]		$ 1,660,000,000
SIGECO [Member] | Letter of Credit [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 21,000,000
Parent Company [Member]
Line of Credit Facility [Abstract]
Size of credit facility				$ 3,300,000,000
Parent Company [Member] | Senior Notes Due 2030 [Member]
Long-term debt:
Principal amount of debt issued						$ 400,000,000
Parent Company [Member] | Senior Notes Due 2024 [Member]
Long-term debt:
Debt instrument interest rate				2.50%
Principal amount of debt issued						500,000,000
Parent Company [Member] | Senior Notes Due 2049 [Member]
Long-term debt:
Principal amount of debt issued						$ 300,000,000
Parent Company [Member] | Pollution control bonds 5.125% due 2028 (5)
Long-term debt:
Debt instrument interest rate				5.125%
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Secured debt amount with asset liens				$ 68,000,000							$ 68,000,000
Long-Term				68,000,000
Parent Company [Member] | Revolving Credit Facility [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit	[12]			$ 0							0
Parent Company [Member] | Line of Credit [Member]
Line of Credit Facility [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	[7]			65.00%
Ratio of indebtedness to net capital	[8]			0.590
Percentage on limitation of debt to total capitalization under covenant amended (in hundredths)				70.00%
System restoration costs threshold for increase in permitted debt to EBITDA covenant ratio				$ 100,000,000
Consecutive period for system restoration costs to exceed $100 million (in months)				12
Parent Company [Member] | Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Abstract]
Basis spread on LIBOR	[9]			1.50%
Parent Company [Member] | Letter of Credit [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit	[12]			$ 6,000,000							6,000,000
Parent Company [Member] | Commercial paper (4)
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit	[12]			$ 1,633,000,000							$ 0
Debt, Weighted Average Interest Rate	[12]			1.95%							0.00%
VUHI [Member]
Line of Credit Facility [Abstract]
Size of credit facility	[13]			$ 400,000,000
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Credit facility swing line sublimit				10,000,000
Letters of credit swing line sublimit				20,000,000
VUHI [Member] | Revolving Credit Facility [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 0	[14]						$ 0
VUHI [Member] | Line of Credit [Member]
Line of Credit Facility [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	[13]			65.00%
Ratio of indebtedness to net capital	[8],[13]			0.516
VUHI [Member] | Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Abstract]
Basis spread on LIBOR	[9],[13]			1.125%
VUHI [Member] | Letter of Credit [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 0	[14]						0
VUHI [Member] | Commercial paper (4)
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 268,000,000	[14]						$ 0
Debt, Weighted Average Interest Rate				2.08%	[14]						0.00%
VCC [Member]
Line of Credit Facility [Abstract]
Size of credit facility	[15]			$ 200,000,000
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Credit facility swing line sublimit				40,000,000
Letters of credit swing line sublimit				80,000,000
VCC [Member] | Revolving Credit Facility [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 0	[16]						$ 0
VCC [Member] | Line of Credit [Member]
Line of Credit Facility [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	[15]			65.00%
Ratio of indebtedness to net capital	[8],[15]			0.580
VCC [Member] | Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Abstract]
Basis spread on LIBOR	[9],[15]			1.25%
VCC [Member] | Letter of Credit [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 0	[16]						0
VCC [Member] | Commercial paper (4)
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 0	[16]						$ 0
Debt, Weighted Average Interest Rate				0.00%	[16]						0.00%
Maximum [Member] | Houston Electric [Member] | General mortgage bonds 1.85% to 6.95% due 2021 to 2048
Long-term debt:
Debt instrument interest rate				6.95%
Maximum [Member] | Parent Company [Member] | Variable rate term loan [Member]
Long-term debt:
Debt instrument interest rate				2.56%
Maximum [Member] | Vectren [Member] | Letter of Credit [Member]
Annual maturities of long term debt, capital leases, and sinking fund requirements, excluding ZENS obligations [Abstract]
Long-term Line of Credit				$ 50,000,000
[1]	Draw down by VCC on its variable rate term loan.
[2]	Classified as long-term debt because the termination date of the facility that backstops the commercial paper is more than one year from the date noted.
[3]	Commercial paper issued by VUHI has maturities up to 30 days.
[4]	$68 million and $68 million of these series of debt were secured by general mortgage bonds of Houston Electric as of December 31, 2019 and 2018 , respectively. These general mortgage bonds are not reflected in Houston Electric’s consolidated financial statements because of the contingent nature of the obligations.
[5]	These maturities include Securitization Bonds principal repayments on scheduled payment dates.
[6]	Issued by CERC Corp.
[7]	For CenterPoint Energy and Houston Electric, the financial covenant limit will temporarily increase from 65% to 70% if Houston Electric experiences damage from a natural disaster in its service territory and CenterPoint Energy certifies to the administrative agent that Houston Electric has incurred system restoration costs reasonably likely to exceed $100 million in a consecutive 12 -month period, all or part of which Houston Electric intends to seek to recover through securitization financing. Such temporary increase in the financial covenant would be in effect from the date CenterPoint Energy delivers its certification until the earliest to occur of (i) the completion of the securitization financing, (ii) the first anniversary of CenterPoint Energy’s certification or (iii) the revocation of such certification.
[8]	As defined in the revolving credit facility agreement, excluding Securitization Bonds.
[9]	Based on credit ratings as of December 31, 2019 .
[10]	Proceeds from these commercial paper issuances were used to fund a portion of the Merger and to pay related fees and expenses and were contributed to Vectren for its payment of its stub period cash dividend, long-term incentive payments and to fund the repayment of indebtedness of Vectren subsidiaries redeemed at the option of the holder as a result of the closing of the Merger.
[11]	The commercial paper notes were issued at various times in January 2019 with maturities up to and including 90 days as of the time of issuance, and, prior to their use as described in connection with the closing of the Merger, the net proceeds of such issuances were invested in short-term investments.
[12]	CenterPoint Energy’s outstanding commercial paper generally has maturities of 60 days or less.
[13]	This credit facility was issued by VUHI, is guaranteed by SIGECO, Indiana Gas and VEDO and includes a $10 million swing line sublimit and a $20 million letter of credit sublimit. This credit facility backstops VUHI’s commercial paper program.
[14]	This credit facility was issued by VUHI and is guaranteed by SIGECO, Indiana Gas and VEDO.
[15]	This credit facility was issued by VCC, is guaranteed by Vectren and includes a $40 million swing line sublimit and an $80 million letter of credit sublimit.
[16]	This credit facility was issued by VCC and is guaranteed by Vectren.

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Current income tax expense (benefit):
Federal	$ 48		$ 89		$ 32
State	21		9		9
Total current expense (benefit)	69		98		41
Deferred income tax expense (benefit):
Federal	74		(25)		(806)
State	(5)		73		36
Total deferred expense (benefit)	69		48		(770)
Total income tax expense (benefit)	138		146		(729)
Income tax reconciliation [Abstract]
Income before income taxes	$ 929		$ 514		$ 1,063
Federal statutory income tax rate	21.00%		21.00%		35.00%
Expected federal income tax expense	$ 195		$ 108		$ 372
Increase (decrease) in tax expense resulting from:
State income tax expense, net of federal income tax	36		22		26
State valuation allowance, net of federal income tax	(4)	[1]	11	[2]	3
State law change, net of federal income tax	(21)	[1]	32	[2]	0
Federal income tax rate reduction	0		0		(1,113)	[3]
Excess deferred income tax amortization	(55)	[1]	(24)	[2]	0
Other, net	(13)		(3)		(17)
Total	(57)		38		(1,101)
Total income tax expense (benefit)	$ 138		$ 146		$ (729)
Effective tax rate (in hundredths)	15.00%		28.00%		(69.00%)
Deferred tax assets:
Benefits and compensation	$ 152		$ 160
Regulatory liabilities	447		356
Loss and credit carryforwards	111		84
Asset retirement obligations	89		62
Deferred Tax Assets, Derivative Instruments	34		0
Other	40		29
Valuation allowance	(25)		(18)
Total deferred tax assets	848		673
Deferred tax liabilities:
Property, plant, and equipment	2,656		1,894
Investment in unconsolidated affiliates	1,010		987
Regulatory assets	344		395
Investment in marketable securities and indexed debt	586		478
Indexed debt securities derivative	0		27
Other	180		131
Total deferred tax liabilities	4,776		3,912
Net deferred tax liabilities	3,928		3,239
Reconciliation of Unrecognized Tax Benefits, excluding interest and penalties:
Balance, beginning of year	0
Unrecognized tax benefits assumed through the Merger	9
Decreases related to tax positions of prior years	(1)
Balance, end of year	8		0
State and Local Jurisdiction [Member]
Increase (decrease) in tax expense resulting from:
Federal income tax rate reduction	(21)
Deferred tax liabilities:
Operating loss carryforwards	699
Deferred tax assets tax credit carryforwards	21
Houston Electric [Member]
Current income tax expense (benefit):
Federal	84		109		$ 70
State	20		18		19
Total current expense (benefit)	104		127		89
Deferred income tax expense (benefit):
Federal	(24)		(38)		(98)
Total deferred expense (benefit)	(24)		(38)		(98)
Total income tax expense (benefit)	80		89		(9)
Income tax reconciliation [Abstract]
Income before income taxes	$ 436		$ 425		$ 424
Federal statutory income tax rate	21.00%		21.00%		35.00%
Expected federal income tax expense	$ 92		$ 89		$ 148
Increase (decrease) in tax expense resulting from:
State income tax expense, net of federal income tax	16		14		12
Federal income tax rate reduction	0		0		(158)	[4]
Excess deferred income tax amortization	(21)	[5]	(9)	[6]	0
Other, net	(7)		(5)		(11)
Total	(12)		0		(157)
Total income tax expense (benefit)	$ 80		$ 89		$ (9)
Effective tax rate (in hundredths)	18.00%		21.00%		(2.00%)
Deferred tax assets:
Benefits and compensation	$ 14		$ 17
Regulatory liabilities	195		205
Asset retirement obligations	9		7
Other	7		12
Total deferred tax assets	225		241
Deferred tax liabilities:
Property, plant, and equipment	1,129		1,087
Regulatory assets	126		177
Total deferred tax liabilities	1,255		1,264
Net deferred tax liabilities	1,030		1,023
CERC Corp [Member]
Deferred income tax expense (benefit):
Total deferred expense (benefit)	7		31		$ (224)
Total income tax expense (benefit)	14		22		(265)
Income tax reconciliation [Abstract]
Income before income taxes	226		92		319
Increase (decrease) in tax expense resulting from:
State valuation allowance, net of federal income tax	4
Excess deferred income tax amortization	(18)
Total income tax expense (benefit)	14		22		$ (265)
Deferred tax liabilities:
Operating loss carryforwards	618
CERC Corp [Member] | State and Local Jurisdiction [Member]
Increase (decrease) in tax expense resulting from:
Federal income tax rate reduction	(4)
Deferred tax assets:
Valuation allowance	(15)
Deferred tax liabilities:
Operating loss carryforwards	691
Deferred tax assets tax credit carryforwards	17
Federal Income Tax Rate Prior To TCJA [Member]
Income tax reconciliation [Abstract]
Federal statutory income tax rate					35.00%
Federal Income Tax Rate Prior To TCJA [Member] | Houston Electric [Member]
Income tax reconciliation [Abstract]
Federal statutory income tax rate					35.00%
Federal Income Tax Rate Prior To TCJA [Member] | CERC Corp [Member]
Income tax reconciliation [Abstract]
Federal statutory income tax rate					35.00%
Federal Income Tax Rate After TCJA [Member]
Income tax reconciliation [Abstract]
Federal statutory income tax rate					21.00%
Federal Income Tax Rate After TCJA [Member] | Houston Electric [Member]
Income tax reconciliation [Abstract]
Federal statutory income tax rate					21.00%
Federal Income Tax Rate After TCJA [Member] | CERC Corp [Member]
Income tax reconciliation [Abstract]
Federal statutory income tax rate					21.00%
Continuing Operations [Member] | CERC Corp [Member]
Current income tax expense (benefit):
Federal	0		(9)		$ (31)
State	7		0		(10)
Total current expense (benefit)	7		(9)		(41)
Deferred income tax expense (benefit):
Federal	39		10		(249)
State	(32)		21		25
Total deferred expense (benefit)	7		31		(224)
Total income tax expense (benefit)	14		22		(265)
Income tax reconciliation [Abstract]
Income before income taxes	$ 226		$ 92		$ 319
Federal statutory income tax rate	21.00%		21.00%		35.00%
Expected federal income tax expense	$ 47		$ 19		$ 112
Increase (decrease) in tax expense resulting from:
State income tax expense, net of federal income tax	(12)		5		6
State law change, net of federal income tax	(4)	[7]	0		0
Federal income tax rate reduction	0		0		(396)	[8]
Goodwill impairment	8		0		0
Excess deferred income tax amortization	(18)	[7]	(15)	[9]	0
Other, net	(3)		2		(1)
Total	(33)		3		(377)
Total income tax expense (benefit)	$ 14		$ 22		$ (265)
Effective tax rate (in hundredths)	6.00%		24.00%		(83.00%)
Deferred tax assets:
Benefits and compensation	$ 24		$ 27
Regulatory liabilities	144		150
Loss and credit carryforwards	183		259
Asset retirement obligations	80		54
Other	23		20
Valuation allowance	(15)		(18)
Total deferred tax assets	439		492
Deferred tax liabilities:
Property, plant, and equipment	821		773
Regulatory assets	45		41
Other	43		84
Total deferred tax liabilities	909		898
Net deferred tax liabilities	470		406
Discontinued Operations [Member] | CERC Corp [Member]
Current income tax expense (benefit):
Federal	0		9		$ 31
State	0		4		11
Total current expense (benefit)	0		13		42
Deferred income tax expense (benefit):
Federal	0		29		56
State	0		4		6
Total deferred expense (benefit)	0		33		62
Total income tax expense (benefit)	0		46		104
Income tax reconciliation [Abstract]
Income before income taxes	$ 0		$ 184		$ 265
Federal statutory income tax rate	0.00%		21.00%		35.00%
Expected federal income tax expense	$ 0		$ 39		$ 93
Increase (decrease) in tax expense resulting from:
State income tax expense, net of federal income tax	0		7		11
Total	0		7		11
Total income tax expense (benefit)	$ 0		$ 46		$ 104
Effective tax rate (in hundredths)	0.00%		25.00%		39.00%
State Valuation Allowance, net of Federal Income Taxes [Member] | Continuing Operations [Member] | CERC Corp [Member]
Increase (decrease) in tax expense resulting from:
State valuation allowance, net of federal income tax	$ (4)	[7]	$ 11	[9]	$ 3
Tax Basis Balance Sheet Adjustment [Member] | Continuing Operations [Member] | CERC Corp [Member]
Increase (decrease) in tax expense resulting from:
State valuation allowance, net of federal income tax	0		$ 0		$ 11
Charitable Contribution [Member]
Deferred tax liabilities:
Deferred tax assets tax credit carryforwards	26
Vectren [Member]
Deferred tax liabilities:
Operating loss carryforwards	177
Reconciliation of Unrecognized Tax Benefits, excluding interest and penalties:
Unrecognized tax benefits assumed through the Merger	9
Unrecognized Tax benefit, impacting ETR if recognized	3
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	5
Unrecognized Tax Benefit, including penalties and interest	9
Vectren [Member] | Charitable Contribution [Member]
Deferred tax liabilities:
Deferred tax assets tax credit carryforwards	$ 60
[1]	Recognized a $55 million benefit for the amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions, a $21 million net benefit for the impact of state law changes that resulted in the remeasurement of state deferred taxes in those jurisdictions, and $4 million net benefit for the reduction in valuation allowances on certain state net operating losses that are now expected to be realized.
[2]	Recognized a $32 million deferred tax expense due to state law changes that resulted in remeasurement of state deferred taxes in those jurisdictions. Also recorded an additional $11 million valuation allowance on certain state net operating loss deferred tax assets that are no longer expected to be utilized prior to expiration after the Internal Spin. These items are partially offset by $24 million of amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions beginning in 2018.
[3]	Recognized a $1.1 billion deferred tax benefit from the remeasurement of CenterPoint Energy’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% .
[4]	Recognized a $158 million deferred tax benefit from the remeasurement of Houston Electric’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% .
[5]	Recognized $21 million of amortization of the net regulatory EDIT liability as decreed by regulators.
[6]	Recognized $9 million of amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions beginning in 2018.
[7]	Recognized $18 million benefit for the amortization of the net regulatory EDIT liability as decreed by regulators in certain jurisdictions, $4 million net benefit for the impact of state law changes that resulted in the remeasurement of state deferred taxes in those jurisdictions and $4 million net benefit for the reduction in valuation allowances on certain state net operating losses that are now expected to be realized.
[8]	Recognized a $396 million deferred tax benefit from the remeasurement of CERC’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% . ASC 740 requires tax impacts of changes in tax laws or rates be reported in continuing operations. Therefore, CERC’s federal income tax benefit generated by the remeasurement of the ADFIT liability for Enable during 2017 and state law changes during 2016 associated with its investment in Enable are reported in continuing operations on CERC’s Statements of Consolidated Income. The ADFIT liability associated with CERC’s investment in Enable is reported as discontinued operations on CERC’s Consolidated Balance Sheets.
[9]	Recorded an additional $11 million valuation allowance on certain state net operating loss deferred tax assets that are no longer expected to be utilized prior to expiration after the Internal Spin. This item is partially offset by $15 million

Income Taxes Merger with Vectre

Income Taxes Merger with Vectren (Details) - USD ($) $ in Millions	Feb. 01, 2019	Dec. 31, 2019
Vectren [Member]
Business Acquisition [Line Items]
Cash paid to acquire Vectren	$ 6,000	$ 5,982
Operating loss carryforwards		177
Charitable Contribution [Member]
Business Acquisition [Line Items]
Deferred tax assets tax credit carryforwards		26
Charitable Contribution [Member] | Vectren [Member]
Business Acquisition [Line Items]
Deferred tax assets tax credit carryforwards		$ 60

Commitments and Contingencies_2

Commitments and Contingencies (Details)	12 Months Ended
	Dec. 31, 2019USD ($)site	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Purchase Obligations
2020	$ 750,000,000
2021	617,000,000
2022	418,000,000
2023	335,000,000
2024	271,000,000
2025 and beyond	$ 1,888,000,000
Performance Guarantees & Product Warranties [Abstract]
Number of surety bond obligations outstanding	62
Performance guarantee obligations outstanding face amount	$ 565,000,000
Percentage of work yet to be completed on projects with open surety bonds	36.00%
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 499,000,000
Legal, Environmental and Other Matters
Asset Retirement Obligation	$ 539,000,000	$ 258,000,000	$ 281,000,000
Indiana Gas Service Territory [Member]
Legal, Environmental and Other Matters
Environmental remediation number of sites with potential remedial responsibility | site	26
Minnesota and Indiana Gas Service Territories [Member]
Legal, Environmental and Other Matters
Liability recorded for remediation of Minnesota sites	$ 12,000,000
Minnesota and Indiana Gas Service Territories [Member] | Minimum [Member]
Legal, Environmental and Other Matters
Estimated remediation costs for the Minnesota sites	$ 7,000,000
Years to resolve contingency	5
Minnesota and Indiana Gas Service Territories [Member] | Maximum [Member]
Legal, Environmental and Other Matters
Estimated remediation costs for the Minnesota sites	$ 51,000,000
Years to resolve contingency	50
Minnehaha Academy Gas Explosion [Member]
Legal, Environmental and Other Matters
Contested amount of fines imposed	$ 200,000
Indiana Electric [Member]
Legal, Environmental and Other Matters
Asset Retirement Obligation	68,000,000
Indiana Electric [Member] | Minimum [Member]
Legal, Environmental and Other Matters
Estimated capital expenditure to clean ash ponds	60,000,000
Indiana Electric [Member] | Maximum [Member]
Legal, Environmental and Other Matters
Estimated capital expenditure to clean ash ponds	80,000,000
CERC Corp [Member]
Purchase Obligations
2020	533,000,000
2021	432,000,000
2022	242,000,000
2023	182,000,000
2024	174,000,000
2025 and beyond	1,526,000,000
Legal, Environmental and Other Matters
Asset Retirement Obligation	325,000,000	$ 221,000,000	$ 243,000,000
CERC Corp [Member] | Minnesota and Indiana Gas Service Territories [Member]
Legal, Environmental and Other Matters
Liability recorded for remediation of Minnesota sites	7,000,000
CERC Corp [Member] | Minnesota and Indiana Gas Service Territories [Member] | Minimum [Member]
Legal, Environmental and Other Matters
Estimated remediation costs for the Minnesota sites	$ 4,000,000
Years to resolve contingency	30
CERC Corp [Member] | Minnesota and Indiana Gas Service Territories [Member] | Maximum [Member]
Legal, Environmental and Other Matters
Estimated remediation costs for the Minnesota sites	$ 32,000,000
Years to resolve contingency	50
CERC Corp [Member] | Minnehaha Academy Gas Explosion [Member]
Legal, Environmental and Other Matters
Contested amount of fines imposed	$ 200,000
CES natural gas related transactions [Member] | Energy Services [Member]
Performance Guarantees & Product Warranties [Abstract]
Performance guarantee obligations outstanding face amount	1,800,000,000
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 0
Annualized fee received for retained CES obligation guarantees	3.00%
Quarterly increase of fee received for retained CES guarantee exposure	1.00%
Guarantor Obligations, Current Carrying Value	$ 0
CES natural gas related transactions [Member] | Energy Services [Member] | CERC Corp [Member]
Performance Guarantees & Product Warranties [Abstract]
Performance guarantee obligations outstanding face amount	$ 1,800,000,000
Annualized fee received for retained CES obligation guarantees	3.00%
Quarterly increase of fee received for retained CES guarantee exposure	1.00%
Guarantor Obligations, Current Carrying Value	$ 0

Earnings Per Share (CenterPoi_3

Earnings Per Share (CenterPoint Energy) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended																12 Months Ended
		Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Net income																		$ 791		$ 368		$ 1,792
Numerator:
Income available to common shareholders - basic (1)		$ 128		$ 241		$ 165		$ 140		$ 90		$ 153		$ (75)		$ 165		674	[1]	333	[1]	1,792	[1]
Add back: Series B Preferred Stock dividend																		117		35		0
Income available to common shareholders - diluted (1)	[1]																	$ 674		$ 333		$ 1,792
Denominator:
Weighted average common shares outstanding - basic																		502,050,000		448,829,000		430,964,000
Plus: Incremental shares from assumed conversions:
Weighted average common shares outstanding - diluted																		505,157,000		452,465,000		434,308,000
Basic Earnings Per Common Share		$ 0.25	[2]	$ 0.48	[2]	$ 0.33	[2]	$ 0.28	[2]	$ 0.18	[2]	$ 0.35	[2]	$ (0.17)	[2]	$ 0.38	[2]	$ 1.34		$ 0.74		$ 4.16
Diluted Earnings Per Common Share		$ 0.25	[2]	$ 0.47	[2]	$ 0.33	[2]	$ 0.28	[2]	$ 0.18	[2]	$ 0.35	[2]	$ (0.17)	[2]	$ 0.38	[2]	$ 1.33		$ 0.74		$ 4.13
Reduction in income taxes due to tax reform																		$ 0		$ 0		$ 1,113	[3]
Preferred Stock Dividends, Income Statement Impact																		$ 117		$ 35		$ 0
Restricted Stock [Member]
Plus: Incremental shares from assumed conversions:
Restricted stock (3)	[4]																	3,107,000		3,636,000		3,344,000
Series B Preferred Stock [Member]
Numerator:
Add back: Series B Preferred Stock dividend	[5]																	$ 0		$ 0		$ 0
Plus: Incremental shares from assumed conversions:
Series B Preferred Stock (2)	[5]																	0		0		0
Preferred Stock Dividends, Income Statement Impact																		$ 68		$ 17		$ 0
Amount of antidilutive securities excluded from computation of earnings per share																		34,354,000		8,885,000
Vectren [Member]
Net income																		$ 190
[1]	Income available to common shareholders for the year ended December 31, 2019 includes net income from businesses acquired in the Merger of $190 million . See Note 4. Income available to common shareholders for the year ended December 31, 2017 includes a reduction in income tax expense of $1,113 million due to tax reform. See Note 15 for further discussion of the impacts of the TCJA.
[2]	Quarterly earnings (loss) per common share are based on the weighted average number of shares outstanding during the quarter, and the sum of the quarters may not equal annual earnings (loss) per common share.
[3]	Recognized a $1.1 billion deferred tax benefit from the remeasurement of CenterPoint Energy’s ADFIT liability as a result of the enactment of the TCJA on December 22, 2017, which reduced the U.S. corporate income tax rate from 35% to 21% .
[4]	The potentially dilutive impact from restricted stock awards applies the treasury stock method. Under this method, an increase in the average fair market value of Common Stock can result in a greater dilutive impact from these securities.
[5]	The potentially dilutive impact from Series B Preferred Stock applies the if-converted method in calculating diluted earnings per common share. Under this method, diluted earnings per common share is adjusted for the more dilutive effect of the Series B Preferred Stock as a result of either its accumulated dividend for the period in the numerator or the assumed-converted common share equivalent in the denominator. The computation of diluted earnings per common share outstanding for the year ended December 31, 2019 and December 31, 2018 excludes Series B Stock Dividends of $ 68 million and $17 million , respectively, and 34,354,000 and 8,885,000 potentially dilutive shares, respectively, because to include them would be anti-dilutive. However, these shares could be potentially dilutive in the future.

Unaudited Quarterly Informati_3

Unaudited Quarterly Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Revenues	$ 3,230		$ 2,742		$ 2,798		$ 3,531		$ 3,036		$ 2,212		$ 2,186		$ 3,155		$ 12,301		$ 10,589		$ 9,614
Operating income (loss)	302		392		287		245		167		226		187		251		1,226		831		1,136
Income (loss) available to common shareholders	$ 128		$ 241		$ 165		$ 140		$ 90		$ 153		$ (75)		$ 165		$ 674	[1]	$ 333	[1]	$ 1,792	[1]
Basic earnings per common share (1)	$ 0.25	[2]	$ 0.48	[2]	$ 0.33	[2]	$ 0.28	[2]	$ 0.18	[2]	$ 0.35	[2]	$ (0.17)	[2]	$ 0.38	[2]	$ 1.34		$ 0.74		$ 4.16
Diluted earnings per common share (1)	$ 0.25	[2]	$ 0.47	[2]	$ 0.33	[2]	$ 0.28	[2]	$ 0.18	[2]	$ 0.35	[2]	$ (0.17)	[2]	$ 0.38	[2]	$ 1.33		$ 0.74		$ 4.13
Net income																	$ 791		$ 368		$ 1,792
Houston Electric [Member]
Revenues	$ 680		$ 859		$ 765		$ 686		$ 728		$ 897		$ 854		$ 755		2,990		3,234		2,998
Operating income (loss)	99		269		169		81		98		227		181		119		618		625		637
Net income	44		185		100		27		40		143		101		52		356		336		433
CERC Corp [Member]
Revenues	1,734		1,126		1,342		2,368		2,303	[3]	1,312	[3]	1,328	[3]	2,400	[3]	6,570		7,343		6,603
Operating income (loss)	73		23		58		196		76	[3]	(7)	[3]	22	[3]	131	[3]	350		222		467
Income (loss) from continuing operations									35	[3]	(35)	[3]	(8)	[3]	78	[3]	212		70		584
Income (loss) from discontinued operations, net of tax									(2)	[3]	44	[3]	44	[3]	52	[3]	0		138		161
Net income	$ 53		$ (7)		$ 28		$ 138		$ 33	[3]	$ 9	[3]	$ 36	[3]	$ 130	[3]	$ 212		$ 208		$ 745
[1]	Income available to common shareholders for the year ended December 31, 2019 includes net income from businesses acquired in the Merger of $190 million . See Note 4. Income available to common shareholders for the year ended December 31, 2017 includes a reduction in income tax expense of $1,113 million due to tax reform. See Note 15 for further discussion of the impacts of the TCJA.
[2]	Quarterly earnings (loss) per common share are based on the weighted average number of shares outstanding during the quarter, and the sum of the quarters may not equal annual earnings (loss) per common share.
[3]	Amounts have been recast to reflect discontinued operations in all periods presented.

Reportable Segments Financial D

Reportable Segments Financial Data (Details) - USD ($) $ in Millions		3 Months Ended												12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues		$ 3,230	$ 2,742	$ 2,798	$ 3,531	$ 3,036		$ 2,212		$ 2,186		$ 3,155		$ 12,301	$ 10,589	$ 9,614
Depreciation and Amortization														1,287	1,243	1,036
Operating Income (Loss)		302	392	287	245	167		226		187		251		1,226	831	1,136
Total Assets		35,439				27,009								35,439	27,009	22,736
Expenditures for Long-Lived Assets														2,587	1,720	1,494
Capital expenditures per Statements of Consolidated Cash Flows														2,506	1,651	1,426
Capitalized Fees Not Eliminated in Consolidation														162
Midstream Investments’ equity earnings, net														230	307	265
Regulatory Assets		2,129				2,044								2,129	2,044
Enable Midstream Partners [Member]
Segment Reporting Information [Line Items]
Midstream Investments’ equity earnings, net	[1],[2]													229	307	265
Electric Transmission & Distribution [Member]
Segment Reporting Information [Line Items]
Revenues	[3]													2,996	3,232	2,997
Depreciation and Amortization														648	917	724
Operating Income (Loss)														624	623	636
Expenditures for Long-Lived Assets														1,033	952	924
Electric Transmission & Distribution [Member] | Affiliates of NRG Energy, Inc. [Member]
Segment Reporting Information [Line Items]
Revenues														727	705	713
Electric Transmission & Distribution [Member] | Affiliates of Vistra Energy Corp. [Member]
Segment Reporting Information [Line Items]
Revenues														263	251	229
Indiana Electric Integrated [Member]
Segment Reporting Information [Line Items]
Revenues	[3]													523
Depreciation and Amortization														91
Operating Income (Loss)														90
Expenditures for Long-Lived Assets														183
Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Revenues														3,643	2,931	2,606
Depreciation and Amortization														417	277	260
Operating Income (Loss)														408	266	348
Expenditures for Long-Lived Assets														1,098	638	523
Energy Services [Member]
Segment Reporting Information [Line Items]
Revenues														3,653	4,411	3,997
Depreciation and Amortization														16	16	19
Operating Income (Loss)														32	(47)	126
Expenditures for Long-Lived Assets														12	20	11
Infrastructure Services [Member]
Segment Reporting Information [Line Items]
Revenues	[4]													1,186
Depreciation and Amortization														50
Operating Income (Loss)														95
Expenditures for Long-Lived Assets														67
Midstream Investments [Member]
Segment Reporting Information [Line Items]
Revenues	[5]													0	0	0
Depreciation and Amortization	[5]													0	0	0
Operating Income (Loss)	[5]													0	0	0
Expenditures for Long-Lived Assets	[5]													0	0	0
Midstream Investments [Member] | Enable Midstream Partners [Member]
Segment Reporting Information [Line Items]
Midstream Investments’ equity earnings, net														229	307	265
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues														300	15	14
Depreciation and Amortization														65	33	33
Operating Income (Loss)														(23)	(11)	26
Expenditures for Long-Lived Assets														194	110	36
Operating Segments [Member] | Electric Transmission & Distribution [Member]
Segment Reporting Information [Line Items]
Total Assets		11,264				10,509								11,264	10,509	10,292
Operating Segments [Member] | Indiana Electric Integrated [Member]
Segment Reporting Information [Line Items]
Total Assets		3,168												3,168
Operating Segments [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Total Assets		13,903				6,956								13,903	6,956	6,608
Operating Segments [Member] | Energy Services [Member]
Segment Reporting Information [Line Items]
Total Assets		1,301				1,558								1,301	1,558	1,521
Operating Segments [Member] | Infrastructure Services [Member]
Segment Reporting Information [Line Items]
Total Assets		1,077												1,077
Operating Segments [Member] | Midstream Investments [Member]
Segment Reporting Information [Line Items]
Total Assets	[5]	2,473				2,482								2,473	2,482	2,472
Operating Segments [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Total Assets	[6]	4,784				6,156								4,784	6,156	2,497
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues														(173)	(146)	(85)
Total Assets		(2,531)				(652)								(2,531)	(652)	(654)
Intersegment Eliminations [Member] | Electric Transmission & Distribution [Member]
Segment Reporting Information [Line Items]
Revenues														0	0	0
Intersegment Eliminations [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Revenues														(40)	(36)	(33)
Intersegment Eliminations [Member] | Energy Services [Member]
Segment Reporting Information [Line Items]
Revenues														(129)	(110)	(52)
Intersegment Eliminations [Member] | Infrastructure Services [Member]
Segment Reporting Information [Line Items]
Revenues														(4)
Intersegment Eliminations [Member] | Midstream Investments [Member]
Segment Reporting Information [Line Items]
Revenues	[5]													0	0	0
Intersegment Eliminations [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues														0	0	0
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Expenditures for Long-Lived Assets														(81)	(69)	(68)
Houston Electric [Member]
Segment Reporting Information [Line Items]
Revenues		680	859	765	686	728		897		854		755		2,990	3,234	2,998
Depreciation and Amortization														648	917	724
Operating Income (Loss)		99	269	169	81	98		227		181		119		618	625	637
Total Assets		11,262				10,507								11,262	10,507
Capital expenditures per Statements of Consolidated Cash Flows														1,025	922	875
Regulatory Assets		915				1,124								915	1,124
Houston Electric [Member] | Electric Transmission & Distribution [Member] | Affiliates of NRG Energy, Inc. [Member]
Segment Reporting Information [Line Items]
Revenues														727	705	713
Houston Electric [Member] | Electric Transmission & Distribution [Member] | Affiliates of Vistra Energy Corp. [Member]
Segment Reporting Information [Line Items]
Revenues														263	251	229
CERC Corp [Member]
Segment Reporting Information [Line Items]
Revenues		1,734	1,126	1,342	2,368	2,303	[7]	1,312	[7]	1,328	[7]	2,400	[7]	6,570	7,343	6,603
Depreciation and Amortization														305	293	279
Operating Income (Loss)		73	$ 23	$ 58	$ 196	76	[7]	$ (7)	[7]	$ 22	[7]	$ 131	[7]	350	222	467
Total Assets	[8]	8,439				8,214								8,439	8,214	10,112
Expenditures for Long-Lived Assets														785	658	534
Capital expenditures per Statements of Consolidated Cash Flows														776	633	513
Capitalized Fees Not Eliminated in Consolidation														20
Regulatory Assets		203				258								203	258
CERC Corp [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Revenues														2,911	2,931	2,606
Depreciation and Amortization														289	277	260
Operating Income (Loss)														316	266	348
Expenditures for Long-Lived Assets														773	638	523
CERC Corp [Member] | Energy Services [Member]
Segment Reporting Information [Line Items]
Revenues														3,654	4,411	3,997
Depreciation and Amortization														16	16	19
Operating Income (Loss)														32	(47)	126
Expenditures for Long-Lived Assets														12	20	11
CERC Corp [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues														5	1	0
Depreciation and Amortization														0	0	0
Operating Income (Loss)														2	3	(7)
Expenditures for Long-Lived Assets														0	0	0
CERC Corp [Member] | Operating Segments [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Total Assets	[8]	7,497				6,956								7,497	6,956	6,608
CERC Corp [Member] | Operating Segments [Member] | Energy Services [Member]
Segment Reporting Information [Line Items]
Total Assets	[8]	1,301				1,558								1,301	1,558	1,521
CERC Corp [Member] | Operating Segments [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Total Assets	[8]	149				66								149	66	70
CERC Corp [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues														(168)	(146)	(85)
Total Assets	[8]	(508)				(366)								(508)	(366)	(559)
CERC Corp [Member] | Intersegment Eliminations [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Revenues														(40)	(36)	(33)
CERC Corp [Member] | Intersegment Eliminations [Member] | Energy Services [Member]
Segment Reporting Information [Line Items]
Revenues														(128)	(110)	(52)
CERC Corp [Member] | Intersegment Eliminations [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues														0	0	0
CERC Corp [Member] | Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Expenditures for Long-Lived Assets														(9)	(25)	(21)
Pension and Other Postretirement Plans Costs [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Regulatory Assets		584				$ 665								584	$ 665	600
Cash and Cash Equivalents [Member]
Segment Reporting Information [Line Items]
Short-term Investments		$ 3,900												3,900
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | Enable Midstream Partners [Member] | CERC Corp [Member]
Segment Reporting Information [Line Items]
Revenues																0
Depreciation and Amortization																0
Operating Income (Loss)																0
Investment in unconsolidated affiliates - discontinued operations	[8]															2,472
Expenditures for Long-Lived Assets																$ 0
Infrastructure Services [Member]
Segment Reporting Information [Line Items]
Capitalized Fees Not Eliminated in Consolidation														$ 162
[1]	Equity earnings for the year ended December 31, 2019 includes CenterPoint Energy’s share of Enable’s $86 million goodwill impairment recorded in the fourth quarter of 2019.
[2]	Represents amounts billed for certain support services provided to Enable. Actual support services costs are recorded net of reimbursement.
[3]	CenterPoint Energy’s Houston Electric T&D’s revenues from major customers are as follows: Year Ended December 31, 2019 2018 2017 (in millions) Affiliates of NRG $ 727 $ 705 $ 713 Affiliates of Vistra Energy Corp. 263 251 229
[4]	Includes revenues not eliminated in consolidation for pipeline construction and repair services of $162 million capitalized by CenterPoint Energy’s NGD for the 11 months ended December 31, 2019. See Note 2(b).
[5]	CenterPoint Energy’s Midstream Investments’ equity earnings, net are as follows: Year Ended December 31, 2019 2018 2016 (in millions) Enable $ 229 $ 307 $ 265
[6]	Total assets included pension and other postemployment-related regulatory assets of $584 million , $665 million and $600 million as of December 31, 2019 , 2018 and 2017 , respectively. Additionally, total assets as of December 31, 2018 included $3.9 billion of temporary investments included in Cash and cash equivalents on CenterPoint Energy’s Consolidated Balance Sheets.
[7]	Amounts have been recast to reflect discontinued operations in all periods presented.
[8]	On September 4, 2018, CERC completed the Internal Spin. For further information regarding the Internal Spin, see Note 11 .

Reportable Segments Revenues by

Reportable Segments Revenues by Products and Services (Details) - USD ($) $ in Millions	3 Months Ended												12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues by Products and Services:
Revenues	$ 3,230	$ 2,742	$ 2,798	$ 3,531	$ 3,036		$ 2,212		$ 2,186		$ 3,155		$ 12,301	$ 10,589	$ 9,614
Electric Delivery [Member]
Revenues by Products and Services:
Revenues													3,019	3,232	2,997
Retail Electric Sales [Member]
Revenues by Products and Services:
Revenues													486
Wholesale Electric Sales [Member]
Revenues by Products and Services:
Revenues													14
Retail Gas Sales [Member]
Revenues by Products and Services:
Revenues													4,802	4,161	3,634
Wholesale Gas Sales [Member]
Revenues by Products and Services:
Revenues													2,312	3,008	2,811
Gas Transportation and Processing [Member]
Revenues by Products and Services:
Revenues													33	32	29
Infrastructure Services [Member]
Revenues by Products and Services:
Revenues													1,186
Energy Products and Services [Member]
Revenues by Products and Services:
Revenues													449	156	143
Houston Electric [Member]
Revenues by Products and Services:
Revenues	680	859	765	686	728		897		854		755		2,990	3,234	2,998
Houston Electric [Member] | Electric Delivery [Member]
Revenues by Products and Services:
Revenues													2,990	3,234	2,998
Houston Electric [Member] | Retail Gas Sales [Member]
Revenues by Products and Services:
Revenues													0	0	0
Houston Electric [Member] | Wholesale Gas Sales [Member]
Revenues by Products and Services:
Revenues													0	0	0
Houston Electric [Member] | Gas Transportation and Processing [Member]
Revenues by Products and Services:
Revenues													0	0	0
Houston Electric [Member] | Energy Products and Services [Member]
Revenues by Products and Services:
Revenues													0	0	0
CERC Corp [Member]
Revenues by Products and Services:
Revenues	$ 1,734	$ 1,126	$ 1,342	$ 2,368	$ 2,303	[1]	$ 1,312	[1]	$ 1,328	[1]	$ 2,400	[1]	6,570	7,343	6,603
CERC Corp [Member] | Electric Delivery [Member]
Revenues by Products and Services:
Revenues													0	0	0
CERC Corp [Member] | Retail Gas Sales [Member]
Revenues by Products and Services:
Revenues													4,070	4,161	3,634
CERC Corp [Member] | Wholesale Gas Sales [Member]
Revenues by Products and Services:
Revenues													2,313	3,008	2,811
CERC Corp [Member] | Gas Transportation and Processing [Member]
Revenues by Products and Services:
Revenues													33	32	29
CERC Corp [Member] | Energy Products and Services [Member]
Revenues by Products and Services:
Revenues													$ 154	$ 142	$ 129
[1]	Amounts have been recast to reflect discontinued operations in all periods presented.

Supplemental Disclosure of Ca_3

Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Interest, net of capitalized interest		$ 436		$ 363		$ 378
Income taxes (refunds), net		155		89		15
Accounts payable related to capital expenditures		236		201		144
Capital distribution associated with the Internal Spin		0		0		0
ROU Asset Obtained In Exchange for Operating Lease Liability, Including Transition Impact of ASC 842 Adoption		44	[1]	0		0
Cash and cash equivalents	[2]	241		4,231
Total cash, cash equivalents and restricted cash shown in Statements of Consolidated Cash Flows		271		4,278		296	$ 381
Other, net [Member]
Interest income		22		28		2
Cash and Cash Equivalents [Member]
Temporary investments		3,900
Prepaid Expenses and Other Current Assets [Member]
Restricted cash		30		46
Other Noncurrent Assets [Member]
Restricted cash		0		1
Houston Electric [Member]
Interest, net of capitalized interest		229		200		205
Income taxes (refunds), net		87		154		76
Accounts payable related to capital expenditures		117		124		104
Capital distribution associated with the Internal Spin		0		0		0
ROU Asset Obtained In Exchange for Operating Lease Liability, Including Transition Impact of ASC 842 Adoption		1	[1]	0		0
Cash and cash equivalents	[3]	216		335
Total cash, cash equivalents and restricted cash shown in Statements of Consolidated Cash Flows		235		370		274	381
Houston Electric [Member] | Other, net [Member]
Interest Income, Other		9		4		2
Houston Electric [Member] | Prepaid Expenses and Other Current Assets [Member]
Restricted cash		19		34
Houston Electric [Member] | Other Noncurrent Assets [Member]
Restricted cash		0		1
CERC Corp [Member]
Interest, net of capitalized interest		109		105		116
Income taxes (refunds), net		7		3		4
Accounts payable related to capital expenditures		86		80		56
Capital distribution associated with the Internal Spin		28	[4],[5]	1,473	[5]	0
ROU Asset Obtained In Exchange for Operating Lease Liability, Including Transition Impact of ASC 842 Adoption		29	[1]	0		0
Cash and cash equivalents		2		14
Total cash, cash equivalents and restricted cash shown in Statements of Consolidated Cash Flows		2		25		$ 12	$ 1
CERC Corp [Member] | Prepaid Expenses and Other Current Assets [Member]
Restricted cash		0		11
CERC Corp [Member] | Other Noncurrent Assets [Member]
Restricted cash		0		0
Bond Companies [Member] | Houston Electric [Member]
Cash and cash equivalents		$ 216		$ 335
[1]	Includes the transition impact of adoption of ASU 2016-02 Leases as of January 1, 2019. The Registrants elected not to recast comparative periods in the year of adoption as permitted by the standard.
[2]	CenterPoint Energy’s Cash and cash equivalents as of December 31, 2018 included $3.9 billion of temporary investments resulting from the Merger financings. CenterPoint Energy recorded interest income of $22 million , $28 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on CenterPoint Energy’s Statements of Consolidated Income. See Notes 13 and 14 for further details related to the Merger financings.
[3]	Houston Electric’s Cash and cash equivalents as of December 31, 2019 and 2018 included $216 million and $335 million , respectively, of cash related to the Bond Companies. Houston Electric recorded interest income of $9 million , $4 million and $2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively, in Other, net on Houston Electric’s Statement of Consolidated Income.
[4]	The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.
[5]	The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.

Related Party Transactions (H_3

Related Party Transactions (Houston Electric and CERC) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Related Party Transaction [Line Items]
Capital distribution to parent associated with the Internal Spin (1)		$ 0		$ 0		$ 0
Houston Electric [Member]
Related Party Transaction [Line Items]
Cash dividends paid to parent		376		209		180
Capital distribution to parent associated with the Internal Spin (1)		0		0		0
Houston Electric [Member] | Other, net [Member]
Related Party Transaction [Line Items]
Interest income (expense), net (1)	[1]	18		1		2
Houston Electric [Member] | Operation And Maintenance Expense [Member]
Related Party Transaction [Line Items]
Net affiliate service charges (billings)		(8)		(17)		(9)
Houston Electric [Member] | Operation And Maintenance Expense [Member] | CenterPoint Energy [Member]
Related Party Transaction [Line Items]
Corporate service charges		177		190		188
Houston Electric [Member] | Accounts and notes receivable (payable) - affiliate companies [Member]
Related Party Transaction [Line Items]
Money pool investments (borrowings) (1)	[2]	$ 481
Money Pool Borrowings	[2]			$ (1)
Houston Electric [Member] | Investments [Member]
Related Party Transaction [Line Items]
Weighted average interest rate		1.98%		2.42%
CERC Corp [Member]
Related Party Transaction [Line Items]
Cash dividends paid to parent		$ 120		$ 360		601
Capital distribution to parent associated with the Internal Spin (1)		28	[3],[4]	1,473	[4]	0
CERC Corp [Member] | Other, net [Member]
Related Party Transaction [Line Items]
Interest income (expense), net (1)	[1]	4		0		0
CERC Corp [Member] | Operation And Maintenance Expense [Member]
Related Party Transaction [Line Items]
Net affiliate service charges (billings)		8		17		9
Pipeline construction and repair service charges	[5]	4
CERC Corp [Member] | Operation And Maintenance Expense [Member] | CenterPoint Energy [Member]
Related Party Transaction [Line Items]
Corporate service charges		141		147		128
CERC Corp [Member] | Non-utility revenue [Member]
Related Party Transaction [Line Items]
Natural gas sales	[6]	1
CERC Corp [Member] | Accounts and notes receivable (payable) - affiliate companies [Member]
Related Party Transaction [Line Items]
Money pool investments (borrowings) (1)	[2]	$ 0		$ 114
CERC Corp [Member] | Investments [Member]
Related Party Transaction [Line Items]
Weighted average interest rate		1.98%		2.42%
Additional Paid-in Capital [Member] | Houston Electric [Member]
Related Party Transaction [Line Items]
Contribution From Parent		$ 590		$ 200		0
Additional Paid-in Capital [Member] | CERC Corp [Member]
Related Party Transaction [Line Items]
Contribution From Parent		129		960		38
Capital distribution to parent associated with the Internal Spin (1)		$ (28)		$ (1,473)		$ 0
[1]	Interest income is included in Other, net and interest expense is included in Interest and other finance charges on Houston Electric’s and CERC’s respective Statements of Consolidated Income.
[2]	Included in Accounts and notes receivable (payable)–affiliated companies in Houston Electric’s and CERC’s Consolidated Balance Sheets.
[3]	The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.
[4]	The capital distribution in 2019 associated with the Internal Spin is a result of the return to accrual for the periods of CERC’s ownership during 2018.
[5]	Represents charges from Infrastructure Services to CERC’s NGD for the period February 1, 2019 through December 31, 2019.
[6]	Represents sales to Indiana Electric from CES for the period February 1, 2019 through December 31, 2019.

Leases (Details)

Leases (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Lease, Cost [Abstract]
Operating lease cost		$ 25
Short-term lease cost		75
Variable lease cost		1
Total lease cost		101
Operating Leases, Lease Income [Abstract]
Operating lease income		4
Variable lease income		2
Total lease income		6
Assets and Liabilities, Lessee [Abstract]
Operating ROU assets (1)	[1]	63
Total leased assets		63	$ 30
Current operating lease liability (2)	[2]	21
Non-current operating lease liability (3)	[3]	42
Total leased liabilities		$ 63
Weighted-average remaining lease term (in years) - operating leases		5 years 1 month 6 days
Weighted-average discount rate - operating leases		3.42%
Operating Lease Liabilities, Payments Due [Abstract]
2020		$ 22
2021		16
2022		9
2023		7
2024		3
2025 and beyond		12
Total lease payments		69
Less: Interest		6
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	[4]			$ 6
2020	[4]			6
2021	[4]			5
2022	[4]			4
2023	[4]			3
2024 and beyond	[4]			12
Total (1)	[4]			36
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
2020		3
2021		2
2022		2
2023		2
2024		2
2025 and beyond		10
Total lease payments to be received		21
Other Information Related to Leases [Abstract]
Operating cash flows from operating leases included in the measurement of lease liabilities		25
Lessee Operating Lease Not Yet Commenced		16
Houston Electric [Member]
Lease, Cost [Abstract]
Operating lease cost		0
Short-term lease cost		23
Variable lease cost		0
Total lease cost		23
Operating Leases, Lease Income [Abstract]
Operating lease income		2
Variable lease income		0
Total lease income		2
Assets and Liabilities, Lessee [Abstract]
Operating ROU assets (1)	[1]	1
Total leased assets		1	1
Current operating lease liability (2)	[2]	0
Non-current operating lease liability (3)	[3]	1
Total leased liabilities		$ 1
Weighted-average remaining lease term (in years) - operating leases		5 years 2 months 12 days
Weighted-average discount rate - operating leases		3.52%
Operating Lease Liabilities, Payments Due [Abstract]
2020		$ 1
2021		0
2022		0
2023		0
2024		0
2025 and beyond		0
Total lease payments		1
Less: Interest		0
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019				1
2020				0
2021				0
2022				0
2023				0
2024 and beyond				0
Total (1)				1
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
2020		1
2021		0
2022		0
2023		0
2024		0
2025 and beyond		0
Total lease payments to be received		1
Other Information Related to Leases [Abstract]
Operating cash flows from operating leases included in the measurement of lease liabilities		1
CERC Corp [Member]
Lease, Cost [Abstract]
Operating lease cost		5
Short-term lease cost		0
Variable lease cost		1
Total lease cost		6
Operating Leases, Lease Income [Abstract]
Operating lease income		1
Variable lease income		0
Total lease income		1
Assets and Liabilities, Lessee [Abstract]
Operating ROU assets (1)	[1]	24
Total leased assets		24	$ 27
Current operating lease liability (2)	[2]	4
Non-current operating lease liability (3)	[3]	20
Total leased liabilities		$ 24
Weighted-average remaining lease term (in years) - operating leases		7 years 8 months 12 days
Weighted-average discount rate - operating leases		3.67%
Operating Lease Liabilities, Payments Due [Abstract]
2020		$ 6
2021		4
2022		4
2023		3
2024		2
2025 and beyond		9
Total lease payments		28
Less: Interest		4
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019				5
2020				5
2021				4
2022				4
2023				3
2024 and beyond				11
Total (1)				$ 32
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
2020		1
2021		0
2022		0
2023		0
2024		0
2025 and beyond		0
Total lease payments to be received		1
Other Information Related to Leases [Abstract]
Operating cash flows from operating leases included in the measurement of lease liabilities		$ 6
[1]	Reported within Other assets in the Registrants’ respective Consolidated Balance Sheets.
[2]	Reported within Current other liabilities in the Registrants’ respective Consolidated Balance Sheets.
[3]	Reported within Other liabilities in the Registrants’ respective Consolidated Balance Sheets.
[4]	The Merger was completed on February 1, 2019. As such, these amounts are exclusive of Vectren’s leases.

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions

Feb. 24, 2020

Feb. 07, 2020

Feb. 03, 2020

Oct. 17, 2019

Jul. 31, 2019

Apr. 25, 2019

Dec. 12, 2018

Oct. 23, 2018

Jul. 26, 2018

Apr. 26, 2018

Dec. 13, 2017

Oct. 25, 2017

Jul. 27, 2017

Apr. 27, 2017

Jan. 05, 2017

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Subsequent Event [Line Items]

Deferred Tax Liabilities, Net, Noncurrent

$ 3,928

$ 3,239

Common stock dividends declared per share

$ 0.86

$ 1.1200

$ 1.35

Expected cash distribution on Enable Common Units

$ 261

$ 267

$ 0

Series A Preferred Units [Member] | Subsequent Event [Member] | Enable Midstream Partners [Member]

Subsequent Event [Line Items]

Declaration Date

Feb. 7, 2020

Record Date

Feb. 7, 2020

Payment Date

Feb. 14, 2020

Distributions Declared, Per Unit

$ 0.6250

Expected cash distribution on Enable's Series A Preferred Units

$ 9

Common Units [Member] | Subsequent Event [Member] | Enable Midstream Partners [Member]

Subsequent Event [Line Items]

Declaration Date

Feb. 7, 2020

Record Date

Feb. 18, 2020

Payment Date

Feb. 25, 2020

Distributions Declared, Per Unit

$ 0.3305

Expected cash distribution on Enable Common Units

$ 77

Common Stock [Member]

Subsequent Event [Line Items]

Declaration Date

Oct. 17, 2019

Jul. 31, 2019

Apr. 25, 2019

Dec. 12, 2018

Oct. 23, 2018

Jul. 26, 2018

Apr. 26, 2018

Dec. 13, 2017

Oct. 25, 2017

Jul. 27, 2017

Apr. 27, 2017

Jan. 5, 2017

Record Date

Nov. 21, 2019

Aug. 15, 2019

May 16, 2019

Feb. 21, 2019

Nov. 15, 2018

Aug. 16, 2018

May 17, 2018

Feb. 15, 2018

Nov. 16, 2017

Aug. 16, 2017

May 16, 2017

Feb. 16, 2017

Payment Date

Dec. 12, 2019

Sep. 12, 2019

Jun. 13, 2019

Mar. 14, 2019

Dec. 13, 2018

Sep. 13, 2018

Jun. 14, 2018

Mar. 8, 2018

Dec. 8, 2017

Sep. 8, 2017

Jun. 9, 2017

Mar. 10, 2017

Common stock dividends declared per share

$ 0.2875

$ 0.2875

$ 0.2875

$ 0.2875

$ 0.2775

$ 0.2775

$ 0.2775

$ 0.2775

$ 0.2675

$ 0.2675

$ 0.2675

$ 0.2675

$ 0.8625

$ 1.1200

$ 1.3475

Common Stock [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Declaration Date

Feb. 3, 2020

Record Date

Feb. 20, 2020

Payment Date

Mar. 12, 2020

Common stock dividends declared per share

$ 0.2900

Series A Preferred Stock [Member]

Subsequent Event [Line Items]

Declaration Date

Jul. 31, 2019

Dec. 12, 2018

Record Date

Aug. 15, 2019

Feb. 15, 2019

Payment Date

Sep. 3, 2019

Mar. 1, 2019

Preferred stock dividends declared per share

$ 30.6250

$ 32.1563

30.6250

32.1563

0

Series A Preferred Stock [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Declaration Date

Feb. 3, 2020

Record Date

Feb. 14, 2020

Payment Date

Mar. 2, 2020

Preferred stock dividends declared per share

$ 30.6250

Series B Preferred Stock [Member]

Subsequent Event [Line Items]

Declaration Date

Oct. 17, 2019

Jul. 31, 2019

Apr. 25, 2019

Dec. 12, 2018

Oct. 23, 2018

Record Date

Nov. 15, 2019

Aug. 15, 2019

May 15, 2019

Feb. 15, 2019

Nov. 15, 2018

Payment Date

Dec. 2, 2019

Sep. 3, 2019

Jun. 3, 2019

Mar. 1, 2019

Dec. 1, 2018

Preferred stock dividends declared per share

$ 17.5000

$ 17.5000

$ 17.5000

$ 17.5000

$ 11.6667

$ 52.5000

$ 29.1667

$ 0

Series B Preferred Stock [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Declaration Date

Feb. 3, 2020

Record Date

Feb. 14, 2020

Payment Date

Mar. 2, 2020

Preferred stock dividends declared per share

$ 17.5000

Infrastructure Services [Member]

Subsequent Event [Line Items]

Deferred Tax Liabilities, Net, Noncurrent

$ 123

Infrastructure Services [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Sales price of outstanding equity interests

$ 850

Energy Services [Member]

Subsequent Event [Line Items]

Deferred Tax Liabilities, Net, Noncurrent

25

Energy Services [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Sales price of outstanding equity interests

$ 400

CERC Corp [Member]

Subsequent Event [Line Items]

Deferred Tax Liabilities, Net, Noncurrent

470

$ 406

CERC Corp [Member] | Energy Services [Member]

Subsequent Event [Line Items]

Deferred Tax Liabilities, Net, Noncurrent

$ 25

CERC Corp [Member] | Energy Services [Member] | Subsequent Event [Member]

Subsequent Event [Line Items]

Sales price of outstanding equity interests

$ 400