Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Net uncertain tax liability		$ 8
Unrecognized Tax Benefits Decrease		(1)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations		$ 5
Houston Electric [Member]
Effective income tax rate	[1]	13.00%	18.00%
Continuing Operations [Member]
Effective income tax rate	[2]	25.00%	9.00%
Continuing Operations [Member] | CERC Corp [Member]
Effective income tax rate	[3]	21.00%	14.00%
Discontinued Operations [Member]
Effective income tax rate	[4]	10.00%	24.00%
Discontinued Operations [Member] | CERC Corp [Member]
Effective income tax rate	[5]	15.00%	22.00%
Coronavirus Aid Relief And Economic Security Act [Member]
Interest expense deductible limitation		30.00%
Increase in expense deductible limitation		50.00%
Recognized tax benefit from changes in tax laws		$ 19

[1] Houston Electric's lower effective tax rate for the three months ended March 31, 2020 compared to the three months ended March 31, 2019 was primarily due to an increase in the amount of amortization of the net regulatory EDIT liability.

[2] CenterPoint Energy’s higher effective tax rate on the loss from continuing operations for the three months ended March 31, 2020 compared to the three months ended March 31, 2019 was primarily due to lower earnings from the impairment of CenterPoint Energy’s investment in Enable. Other effective tax rate drivers include the non-deductible goodwill impairment at the Indiana Electric Integrated reporting unit, the impact of NOL carryback claims allowed under the CARES Act, and an increase in the amount of remeasurement of state deferred tax liabilities for changes in apportionment, the effects of which were compounded by the book loss in the three months ended March 31, 2020.

[3] CERC’s higher effective tax rate on income from continuing operations for the three months ended March 31, 2020 compared to the three months ended March 31, 2019 was primarily due to a decrease in the amount of amortization of the net regulatory EDIT liability.

[4] CenterPoint Energy’s lower effective tax rate on the loss from discontinued operations for the three months ended March 31, 2020 was primarily due to the non-deductible portions of goodwill impairments on the Energy Services and Infrastructure Services Disposal Groups.

[5] CERC’s lower effective tax rate on the loss from discontinued operations for the three months ended March 31, 2020 was due to the non-deductible portion of the goodwill impairment on the Energy Services Disposal Group.