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
	Mar. 31, 2024	Mar. 31, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 3,444	$ 3,301
Total increase (decrease) in unrealized gains included in cost of products sold	278	479
Purchases	3,789	8,665
Sales	(3,883)	(8,254)
Settlements	(352)	(382)
Transfers into Level 3	544	655
Transfers out of Level 3	(108)	(312)
Balance at end of period	3,712	4,152
Inventories Carried At Market [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	2,713	2,760
Total increase (decrease) in unrealized gains included in cost of products sold	(97)	2
Purchases	3,789	8,665
Sales	(3,883)	(8,254)
Settlements	0	0
Transfers into Level 3	516	605
Transfers out of Level 3	(90)	(275)
Balance at end of period	2,948	3,503
Commodity Derivative Contracts Gains [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	731	541
Total increase (decrease) in unrealized gains included in cost of products sold	375	477
Purchases	0	0
Sales	0	0
Settlements	(352)	(382)
Transfers into Level 3	28	50
Transfers out of Level 3	(18)	(37)
Balance at end of period	$ 764	$ 649