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)(5)	—		250		42		(98		)	194		—		173		47		(82		)	138
Hedged portion of natural gas inventory (5)	—		—		—		—			—		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	—		22		—		—			22		$	—	$	—	$	—	$	—		—
Natural gas derivatives (3)(4)(5)	—		195		24		(161		)	58		—		191		17		(101		)	107
Hedged portion of natural gas inventory (5)	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 1		Level 2		Level 3		Netting (1)			Total		Level 1		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)(5)	—		250		42		(98		)	194		—		173		47		(82		)	138
Hedged portion of natural gas inventory (5)	—		—		—		—			—		1		—		—		—			1
Total assets	$	13	$	250	$	42	$	(98	)	$	207	$	14	$	173	$	47	$	(82	)	$	152
Liabilities
Natural gas derivatives (3)(4)(5)	$	—	$	195	$	24	$	(161	)	$	58	$	—	$	191	$	17	$	(101	)	$	107
Hedged portion of natural gas inventory (5)	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 (5)	$	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.

(5) Amounts are classified as held for sale in the Registrants’ respective Condensed Consolidated Balance Sheets.

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 classified as held for sale, 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)
Continuing operations:
Beginning balance	$	—		$	—		$	(668	)	$	—		$	(717	)	$	—
Total gains	—			—			—			—			49			—
Transfers out of Level 3 (1)	—			—			668			—			—			—
Ending balance	$	—		$	—		$	—		$	—		$	(668	)	$	—
Discontinued operations:
Beginning balance	$	30		$	30		$	46		$	46		$	13		$	13
Total gains	17			17			30			30			47			47
Total settlements	(22		)	(22		)	(39		)	(39		)	(11		)	(11		)
Transfers into Level 3	(1		)	(1		)	5			5			14			14
Transfers out of Level 3	(6		)	(6		)	(12		)	(12		)	(17		)	(17		)
Ending balance (2)	$	18		$	18		$	30		$	30		$	46		$	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:
Continuing operations	$	—		$	—		$	—		$	—		$	49		$	—
Discontinued operations	12			12			18			18			38			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. The Level 3 assets and liabilities as of years ended December 31, 2019, 2018 and 2017 are classified in the CenterPoint Energy’s and CERC’s respective Condensed Consolidated Balance Sheets as held for sale.

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.