The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Derivative Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Credit Risk Related Contingent Features [Abstract]
Aggregate fair value of derivatives with credit risk-related contingent features in a liability position	$ 0		$ 0		$ 14
Fair value of collateral already posted	0		0		7
Additional collateral required to be posted if credit risk contingent features triggered	0		0		7
Indexed debt securities derivative \| Gains (Losses) in Other Income (Expense)
Derivatives, Fair Value [Line Items]
Gain (loss) on derivative instruments not designated as hedging instruments	65	$ (77)	171	$ (51)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	32		32		14
Derivative Liabilities Fair Value	732		732		917
Not Designated as Hedging Instrument \| CERC
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	26		26		12
Derivative Liabilities Fair Value	0		0		0
Not Designated as Hedging Instrument \| Current Assets \| Energy Related Derivative
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	26		26		9
Derivative Liabilities Fair Value	0		0		0
Not Designated as Hedging Instrument \| Current Assets \| Energy Related Derivative \| CERC
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	21		21		8
Derivative Liabilities Fair Value	0		0		0
Not Designated as Hedging Instrument \| Other Current Assets \| Energy Related Derivative
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	6		6		5
Derivative Liabilities Fair Value	0		0		0
Not Designated as Hedging Instrument \| Other Current Assets \| Energy Related Derivative \| CERC
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	5		5		4
Derivative Liabilities Fair Value	0		0		0
Not Designated as Hedging Instrument \| Current Liabilities \| Interest rate contract
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	0		0		0
Derivative Liabilities Fair Value	0		0		2
Not Designated as Hedging Instrument \| Current Liabilities \| Indexed debt securities derivative
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	0		0		0
Derivative Liabilities Fair Value	732		732		903
Not Designated as Hedging Instrument \| Other Noncurrent Liabilities \| Interest rate contract
Derivatives, Fair Value [Line Items]
Derivative Assets Fair Value	0		0		0
Derivative Liabilities Fair Value	0		0		12
Economic hedge \| Interest rate contract
Derivatives, Fair Value [Line Items]
Economic hedge	$ 84		$ 84		$ 84