Stock-Based Incentive Compensation Plans and Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2020

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 2020, 2019 and 2018:

	Year Ended December 31,
	2020		2019		2018
	(in millions)
LTIP compensation expense (1)	$	38	$	28	$	26
Income tax benefit recognized	9		7		6
Actual tax benefit realized for tax deductions	5		12		5

(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 2020:

	Year Ended December 31, 2020
	Shares (Thousands)	Weighted-Average Grant Date Fair Value		Remaining Average Contractual Life (Years)	Aggregate Intrinsic Value (2) (Millions)
Performance Awards (1)
Outstanding and nonvested as of December 31, 2019	3,332	$	28.36
Granted	2,022	23.82
Forfeited or canceled	(1,128)	26.89
Vested and released to participants	(326)	26.64
Outstanding and nonvested as of December 31, 2020	3,900	$	26.58	1.2	$	51
Stock Unit Awards
Outstanding and nonvested as of December 31, 2019	966	$	28.46
Granted	980	21.53
Forfeited or canceled	(129)	27.67
Vested and released to participants	(528)	22.51
Outstanding and nonvested as of December 31, 2020	1,289	$	25.71	1.2	$	28

 

(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 2020, 2019 and 2018:

	Year Ended December 31,
	2020		2019		2018
	(in millions, except for per unit amounts)
Performance Awards
Weighted-average grant date fair value per unit of awards granted	$	23.82	$	31.16	$	26.74
Total intrinsic value of awards received by participants	9		36		12
Vested grant date fair value	9		20		9
Stock Unit Awards
Weighted-average grant date fair value per unit of awards granted	$	21.53	$	31.07	$	26.62
Total intrinsic value of awards received by participants	12		15		9
Vested grant date fair value	12		9		7

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

Amounts recognized in accumulated other comprehensive loss (gain) consist of the following:

	December 31,
	2020						2019
	Pension Benefits		Postretirement Benefits				Pension Benefits		Postretirement Benefits
	CenterPoint Energy		CenterPoint Energy		CERC		CenterPoint Energy		CenterPoint Energy		CERC
	(in millions)
Unrecognized actuarial loss (gain)	$	109	$	(14)	$	(12)	$	105	$	(16)	$	(12)
Unrecognized prior service cost	—		7		7		—		7		7
Net amount recognized in accumulated other comprehensive loss (gain)	$	109	$	(7)	$	(5)	$	105	$	(9)	$	(5)

Changes in accumulated comprehensive income (loss) are as follows:

	Year Ended December 31,
	2020						2019
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
	(in millions)
Beginning Balance	$	(98)	$	(15)	$	10	$	(108)	$	(14)	$	5
Other comprehensive income (loss) before reclassifications:
Remeasurement of pension and other postretirement plans	(12)		—		—		7		—		7
Deferred loss from interest rate derivatives (1)	—		—		—		(3)		(1)		—
Reclassified to earnings	—		—		—		1		—		—
Other comprehensive loss from unconsolidated affiliates	(2)		—		—		(1)		—		—
Amounts reclassified from accumulated other comprehensive loss:
Prior service cost (2)	—		—		1		1		—		—
Actuarial losses (2)	7		—		—		8		—		—
Reclassification of deferred loss from cash flow hedges (3)	19		19		—		—		—		—
Tax benefit (expense)	(4)		(4)		(1)		(3)		—		(2)
Net current period other comprehensive income (loss)	8		15		—		10		(1)		5
Ending Balance	$	(90)	$	—	$	10	$	(98)	$	(15)	$	10

(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 $-0- and $1 million for the years ended December 31, 2020 and 2019, 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.

(3)The cost of debt approved by the PUCT as part of Houston Electric’s Stipulation and Settlement Agreement included unrealized gains and losses on interest rate hedges. Accordingly, deferred gains and losses on interest rate hedges were reclassified to regulatory assets or liabilities, as appropriate.

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 2020 are as follows:

	Pension Benefits		Postretirement Benefits
	CenterPoint Energy		CenterPoint Energy		CERC
	(in millions)
Net loss (gain)	$	11	$	2	$	—
Amortization of net loss	(7)		—		—
Amortization of prior service cost	—		—		—
Total recognized in comprehensive income	$	4	$	2	$	—
Total recognized in net periodic costs and Other comprehensive income	$	53	$	6	$	4

Benefit Plan Contributions [Table Text Block]

The Registrants made the following contributions in 2020 and expect to make the following minimum contributions in 2021 to the indicated benefit plans below:

	Contributions in 2020						Expected Minimum Contributions in 2021
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
	(in millions)
Qualified pension plans	$	76	$	—	$	—	$	53	$	—	$	—
Non-qualified pension plans	10		—		—		8		—		—
Postretirement benefit plans	10		3		3		9		1		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)
2021	$	174	$	17	$	8	$	4
2022	176		18		9		5
2023	176		20		9		5
2024	175		21		10		5
2025	173		21		10		6
2026-2030	775		109		53		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 2020, 2019 and 2018:

	Year Ended December 31,
	2020						2019						2018
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
	(in millions)
Savings plan benefit  expenses (1)	$	58	$	18	$	19	$	58	$	18	$	18	$	43	$	17	$	18

Other Benefit Plans [Table Text Block]

Expenses related to other benefit plans were recorded as follows:

	Year Ended December 31,
	2020						2019						2018
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
	(in millions)
Postemployment benefits	$	1	$	1	$	—	$	2	$	1	$	1	$	3	$	4	$	1
Deferred compensation plans	4		1		—		4		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, 2020						December 31, 2019
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
	(in millions)
Postemployment benefits	$	8	$	3	$	5	$	11	$	3	$	7
Deferred compensation plans	43		7		2		41		8		3
Split-dollar life insurance arrangements	32		1		—		32		1		—

Other Employee Matters [Table Text Block]

As of December 31, 2020, 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 2023	15	%	53	%	—
OPEIU Local 12	May 2021	2	%	—		3	%
OPEIU Mankato	March 2021	—	%	—		—	%
Gas Workers Union Local 340	April 2025	4	%	—		12	%
IBEW Locals 1393 and USW Locals 12213 & 7441	December 2023	3	%	—		—	%
IBEW Locals 949	December 2025	3	%	—		7	%
USW Locals 13-227	June 2022	4	%	—		13	%
USW Locals 13-1	July 2022	—	%	—		1	%
IBEW Local 702	June 2022	3	%	—		—
Teamsters Local 135	September 2021	1	%	—		—
UWUA Local 175	October 2021	1	%	—		—
Total		36	%	53	%	36	%

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,
	2020		2019		2018
	(in millions)
Service cost (1)	$	43	$	40	$	37
Interest cost (2)	75		96		79
Expected return on plan assets (2)	(112)		(105)		(107)
Amortization of prior service cost (2)	—		9		9
Amortization of net loss (2)	41		52		43
Settlement cost (2) (3)	2		2		—
Curtailment gain (2) (4)	—		(1)		—
Net periodic cost	$	49	$	93	$	61

 

(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 2020 and 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 Date.

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,
	2020		2019		2018
Discount rate	3.20	%	4.35	%	3.65	%
Expected return on plan assets	5.75		6.00		6.00
Rate of increase in compensation levels	4.95		4.60		4.45

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, 2020 and 2019.

	December 31,
	2020			2019
	(in millions, except for actuarial assumptions)
Change in Benefit Obligation
Benefit obligation, beginning of year	$	2,453		$	2,013
Plan obligations assumed in Merger	—			332
Service cost	43			40
Interest cost	75			96
Benefits paid	(207)			(244)
Actuarial (gain) loss (1)	143			216
Plan amendment	—			1
Curtailment	—			(1)
Benefit obligation, end of year	2,507			2,453
Change in Plan Assets
Fair value of plan assets, beginning of year	2,005			1,516
Plan assets assumed in Merger	—			286
Employer contributions	86			109
Benefits paid	(207)			(244)
Actual investment return	251			338
Fair value of plan assets, end of year	2,135			2,005
Funded status, end of year	$	(372)		$	(448)
Amounts Recognized in Balance Sheets
Current liabilities-other	$	(8)		$	(8)
Other liabilities-benefit obligations	(364)			(440)
Net liability, end of year	$	(372)		$	(448)
Actuarial Assumptions
Discount rate (2)	2.45		%	3.20		%
Expected return on plan assets (3)	5.00			5.75
Rate of increase in compensation levels	5.05			4.95
Interest crediting rate	2.25			3.25

(1)Significant sources of loss for 2020 include the decrease in discount rate from 3.20% to 2.45%, partially offset by significant sources of gain that include actual return on plan assets exceeding expected return on assets during 2020. Significant sources of loss for 2019 include the decrease in discount rate from 4.35% to 3.20%.

(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,
	2020				2019
	Pension (Qualified)		Pension (Non-qualified)		Pension (Qualified)		Pension (Non-qualified)
	(in millions)
Accumulated benefit obligation	$	2,427	$	68	$	2,352	$	68
Projected benefit obligation	2,440		68		2,385		68
Fair value of plan assets	2,135		—		2,005		—

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, 2020:

	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, 2020 and 2019:

	Fair Value Measurements as of December 31,
	2020								2019
	(Level 1)		(Level 2)		(Level 3)		Total		(Level 1)		(Level 2)		(Level 3)		Total
	(in millions)
Cash	$	29	$	—	$	—	$	29	$	(7)	$	—	$	—	$	(7)
Corporate bonds:
Investment grade or above	—		767		—		767		—		699		—		699
Equity securities:
U.S. companies	76		—		—		76		69		—		—		69
Cash received as collateral from securities lending	81		—		—		81		61		—		—		61
U.S. treasuries	225		—		—		225		232		—		—		232
Mortgage backed securities	—		5		—		5		—		8		—		8
Asset backed securities	—		3		—		3		—		3		—		3
Municipal bonds	—		43		—		43		—		44		—		44
Mutual funds (2)	301		—		—		301		270		—		—		270
International government bonds	—		18		—		18		—		21		—		21
Obligation to return cash received as collateral from securities lending	(81)		—		—		(81)		(61)		—		—		(61)
Total investments at fair value	$	631	$	836	$	—	$	1,467	$	564	$	775	$	—	$	1,339
Investments measured by net asset value per share or its equivalent (1) (2)							668								666
Total Investments							$	2,135							$	2,005

(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,
	2020				2019
	Mutual Funds		Common Collective Trust Funds		Mutual Funds		Common Collective Trust Funds
International equities	14	%	37	%	31	%	29	%
U.S. equities	55	%	3	%	49	%	51	%
Real estate	5	%	1	%	1	%	6	%
Fixed income	27	%	59	%	19	%	14	%

Level 2 investments, which do not have a quoted price in active market, are valued using the market data provided by independent pricing services or major market makers, to arrive at a price a dealer would pay for the security.

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,
	2020						2019						2018
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
	(in millions)
Service cost (1)	$	2	$	—	$	1	$	3	$	1	$	1	$	2	$	—	$	1
Interest cost (2)	11		5		3		15		7		5		13		8		4
Expected return on plan assets (2)	(5)		(4)		(1)		(5)		(4)		(1)		(5)		(4)		(1)
Amortization of prior service cost (credit) (2)	(4)		(5)		1		(5)		(6)		1		(5)		(5)		1
Net postretirement benefit cost (credit)	$	4	$	(4)	$	4	$	8	$	(2)	$	6	$	5	$	(1)	$	5

(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,
	2020						2019						2018
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
Discount rate	3.25	%	3.25	%	3.25	%	3.20	%	3.20	%	3.20	%	3.60	%	3.60	%	3.60	%
Expected return on plan assets	3.95		4.05		3.35		4.60		4.70		4.15		4.55		4.75		3.85

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, 2020 and 2019.

	December 31,
	2020									2019
	CenterPoint Energy			Houston Electric			CERC			CenterPoint Energy			Houston Electric			CERC
	(in millions, except for actuarial assumptions)
Change in Benefit Obligation
Benefit obligation, beginning of year	$	356		$	162		$	102		$	331		$	166		$	110
Plan obligations assumed in Merger	—			—			—			37			—			—
Service cost	2			—			1			3			1			1
Interest cost	11			5			3			15			7			5
Participant contributions	6			2			2			8			2			4
Benefits paid	(22)			(10)			(6)			(26)			(13)			(8)
Plan amendment	—			—			—			9			3			5
Actuarial (gain) loss (1)	13			9			3			(21)			(4)			(15)
Benefit obligation, end of year	366			168			105			356			162			102
Change in Plan Assets
Fair value of plan assets, beginning of year	128			101			27			114			89			25
Employer contributions	10			3			3			17			10			3
Participant contributions	6			2			2			8			2			4
Benefits paid	(22)			(10)			(6)			(26)			(13)			(8)
Actual investment return	12			10			2			15			13			3
Fair value of plan assets, end of year	134			106			28			128			101			27
Funded status, end of year	$	(232)		$	(62)		$	(77)		$	(228)		$	(61)		$	(75)
Amounts Recognized in Balance Sheets
Current liabilities-other	$	(9)		$	—		$	(3)		$	(8)		$	—		$	(3)
Other liabilities-benefit obligations	(223)			(62)			(74)			(220)			(61)			(72)
Net liability, end of year	$	(232)		$	(62)		$	(77)		$	(228)		$	(61)		$	(75)
Actuarial Assumptions
Discount rate (2)	2.50		%	2.50		%	2.50		%	3.25		%	3.25		%	3.25		%
Expected return on plan assets (3)	3.20			3.30			2.85			3.95			4.05			3.35
Medical cost trend rate assumed for the next year - Pre-65	5.25			5.25			5.25			5.50			5.50			5.50
Medical/prescription drug cost trend rate assumed for the next year - Post-65	19.70			19.70			19.70			5.75			5.75			5.75
Prescription drug cost trend rate assumed for the next year - Pre-65	7.50			7.50			7.50			8.00			8.00			8.00
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			2028			2028			2028
Year that the cost trend rates reach the ultimate trend rate - Post-65	2029			2029			2029			2029			2029			2029

(1)Significant sources of loss for 2020 include the decrease in discount rate from 3.25% to 2.50%, partially offset by significant sources of gain that include the decrease in interest credit rate from 3.25% to 2.25% and change in mortality projection scale from MP2019 to MP2020. 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.

(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, 2020:

	CenterPoint Energy				Houston Electric				CERC
	Minimum		Maximum		Minimum		Maximum		Minimum		Maximum
U.S. equities	13	%	23	%	13	%	23	%	15	%	25	%
International equities	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, 2020 and 2019:

	Fair Value Measurements as of December 31,
	2020								2019
	Mutual Funds
	(Level 1)		(Level 2)		(Level 3)		Total		(Level 1)		(Level 2)		(Level 3)		Total
	(in millions)
CenterPoint Energy	$	134	$	—	$	—	$	134	$	128	$	—	$	—	$	128
Houston Electric	106		—		—		106		101		—		—		101
CERC	28		—		—		28		27		—		—		27

The amounts invested in mutual funds were allocated as follows:

	As of December 31,
	2020						2019
	CenterPoint Energy		Houston Electric		CERC		CenterPoint Energy		Houston Electric		CERC
Fixed income	74	%	74	%	72	%	71	%	71	%	69	%
U.S. equities	19	%	18	%	21	%	21	%	21	%	24	%
International equities	7	%	8	%	7	%	8	%	8	%	7	%