Derivative Instruments - Cash Flow Derivatives (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Asset	[1]	$ 449	$ 402
Derivative Liability	[1]	364	288
Interest rate hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Asset		0	12
Derivative Liability		161	31
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Asset		0	12
Derivative Liability		119	29
Designated as Hedging Instrument | Interest rate hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Asset		0	12
Derivative Liability		119	29
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Asset		449	390
Derivative Liability		245	259
Not Designated as Hedging Instrument | Interest rate hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Asset		0	0
Derivative Liability		42	2
Not Designated as Hedging Instrument | Energy Related Derivative
Derivatives, Fair Value [Line Items]
Derivative Asset		449	390
Derivative Liability		$ 203	$ 257

[1] At June 30, 2020 and December 31, 2019, we had $260 million and $191 million, respectively, of collateral under master netting arrangements that were not offset against our derivative instruments on the Consolidated Condensed Balance Sheets primarily related to initial margin requirements.