Fair Value Measurements (Reconciliation Of Assets 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, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 3,745	$ 4,125	$ 3,301	$ 3,464
Total increase (decrease) in unrealized gains included in cost of products sold	465	660	1,781	2,043
Purchases	6,615	13,294	25,190	34,524
Sales	(6,539)	(13,931)	(25,439)	(35,239)
Settlements	(356)	(456)	(1,199)	(1,227)
Transfers into Level 3	385	433	1,827	1,298
Transfers out of Level 3	(553)	(337)	(1,699)	(1,075)
Balance at end of period	3,762	3,788	3,762	3,788
Inventories Carried At Market [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	2,859	3,245	2,760	3,004
Total increase (decrease) in unrealized gains included in cost of products sold	135	315	499	746
Purchases	6,615	13,294	25,190	34,524
Sales	(6,539)	(13,931)	(25,439)	(35,239)
Settlements	0	0	(4)	0
Transfers into Level 3	336	384	1,488	933
Transfers out of Level 3	(534)	(221)	(1,622)	(882)
Balance at end of period	2,872	3,086	2,872	3,086
Commodity Derivative Contracts Gains [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	886	880	541	460
Total increase (decrease) in unrealized gains included in cost of products sold	330	345	1,282	1,297
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	(356)	(456)	(1,195)	(1,227)
Transfers into Level 3	49	49	339	365
Transfers out of Level 3	(19)	(116)	(77)	(193)
Balance at end of period	$ 890	$ 702	$ 890	$ 702