Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Derivatives and Risk Management Activities - Net Unrealized Gain/(Loss) Recognized in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Derivative assets and liabilities
Net loss in reclassified to earnings	$ 3	$ 3	$ 5	$ 5
Net loss expected to be reclassified to earnings in the next twelve months			13
Other long-term liabilities and deferred credits
Derivative assets and liabilities
Interest rate fair value hedge liability at fair value	5		5
Other current liabilities
Derivative assets and liabilities
Interest rate fair value hedge liability at fair value					$ 44
AOCI cash flow hedge
Derivative assets and liabilities
Net loss deferred in AOCI	315		315
Interest Rate Derivatives
Derivative assets and liabilities
Net unrealized gain/(loss) recognized in AOCI	$ 19	$ (35)	$ (61)	$ (58)