Assets and Liabilities with Recurring Fair Value Measurements Fair Value Hierarchy (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	$ 417	$ 784
Derivative Asset	[2]	449	402
Effect of Netting and Allocation of Collateral	[3],[4]	(1,330)	(1,021)
Total assets		866	1,186
Derivative Liability	[2]	364	288
Effect of Netting and Allocation of Collateral, Liability	[3],[4]	(1,337)	(1,135)
Total Liabilities		364	288
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	417	784
Effect of Netting and Allocation of Collateral	[3],[4]	(991)	(872)
Total assets		417	784
Effect of Netting and Allocation of Collateral, Liability	[3],[4]	(1,001)	(984)
Total Liabilities		0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	0	0
Effect of Netting and Allocation of Collateral	[3],[4]	(299)	(131)
Total assets		125	126
Effect of Netting and Allocation of Collateral, Liability	[3],[4]	(296)	(133)
Total Liabilities		286	183
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	[1]	0	0
Effect of Netting and Allocation of Collateral	[3],[4]	(40)	(18)
Total assets		324	276
Effect of Netting and Allocation of Collateral, Liability	[3],[4]	(40)	(18)
Total Liabilities		78	105
Commodity exchange traded derivatives contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		991	872
Derivative Liability		1,001	984
Commodity exchange traded derivatives contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		991	872
Derivative Liability		1,001	984
Commodity exchange traded derivatives contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		0	0
Derivative Liability		0	0
Commodity exchange traded derivatives contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		0	0
Derivative Liability		0	0
Commodity forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	[5]	788	539
Derivative Liability	[5]	539	408
Commodity forward contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	[5]	0	0
Derivative Liability	[5]	0	0
Commodity forward contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	[5]	424	245
Derivative Liability	[5]	421	285
Commodity forward contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	[5]	364	294
Derivative Liability	[5]	118	123
Interest rate hedging instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		0	12
Derivative Liability		161	31
Interest rate hedging instruments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		0	0
Derivative Liability		0	0
Interest rate hedging instruments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		0	12
Derivative Liability		161	31
Interest rate hedging instruments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		0	0
Derivative Liability		$ 0	$ 0

[1] At June 30, 2020 and December 31, 2019, we had cash equivalents of $190 million and $573 million included in cash and cash equivalents and $227 million and $211 million included in restricted cash, respectively.

[2] 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.

[3] Cash collateral posted with (received from) counterparties allocated to level 1, level 2 and level 3 derivative instruments totaled $10 million, $(3) million and nil, respectively, at June 30, 2020. Cash collateral posted with (received from) counterparties allocated to level 1, level 2 and level 3 derivative instruments totaled $112 million, $2 million and nil, respectively, at December 31, 2019.

[4] We offset fair value amounts recognized for derivative instruments executed with the same counterparty under a master netting arrangement for financial statement presentation; therefore, amounts recognized for the right to reclaim, or the obligation to return, cash collateral are presented net with the corresponding derivative instrument fair values. See Note 6 for further discussion of our derivative instruments subject to master netting arrangements.

[5] Includes OTC swaps and options.