Fair Value Measurements (Reconciliation Of Liabilities Measured At Fair Value On A Recurring Basis) (Details) - Significant Unobservable Inputs (Level 3) [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 856	$ 1,026	$ 698	$ 936
Total increase (decrease) in unrealized losses included in cost of products sold	287	386	1,061	2,047
Purchases	29	167	36	176
Sales		(5)		(61)
Settlements	(529)	(634)	(1,270)	(2,363)
Transfers into Level 3	10	57	136	379
Transfers out of Level 3	(17)	(65)	(25)	(182)
Balance at end of period	636	932	636	932
Long-term Debt [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period		11	6	15
Total increase (decrease) in unrealized losses included in cost of products sold		(8)	(6)	(12)
Purchases		0	0	0
Balance at end of period	0	3	0	3
Inventory Related Payables [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	65	55	89	106
Total increase (decrease) in unrealized losses included in cost of products sold	(3)	3	(1)	(1)
Purchases	29	167	36	176
Sales		(5)		(61)
Settlements	0	0	(34)	0
Transfers into Level 3	0	0	1	0
Transfers out of Level 3	(4)	0	(4)	0
Balance at end of period	87	220	87	220
Commodity Derivative Contracts Losses [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	791	960	603	815
Total increase (decrease) in unrealized losses included in cost of products sold	290	391	1,068	2,060
Purchases	0	0	0	0
Sales		0		0
Settlements	(529)	(634)	(1,236)	(2,363)
Transfers into Level 3	10	57	135	379
Transfers out of Level 3	(13)	(65)	(21)	(182)
Balance at end of period	$ 549	$ 709	$ 549	$ 709