Derivative Assets And Liabilities Fair Value of Derivatives, Netting Basis (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 455	$ 384
Derivative Liability, Fair Value, Gross Liability	(1,043)	(788)
Derivative Asset, Fair Value, Amount Offset Against Collateral	(53)	(18)
Derivative Liability, Fair Value, Amount Offset Against Collateral	53	18
Derivative Asset, Collateral, Obligation to Return Cash, Offset	(349)	(318)
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	349	318
Derivative Asset, Fair Value, Net	53	48
Derivative Liability, Fair Value, Net	(641)	(452)
Without offsetting agreements [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(577)	(399)
OTC Contracts [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	67	41
Derivative Liability, Fair Value, Gross Liability	(77)	(39)
Broker cleared derivative contracts [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	388	343
Derivative Liability, Fair Value, Gross Liability	$ (389)	$ (350)

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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