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, 2022	Mar. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 3,464	$ 3,042
Total increase (decrease) in unrealized gains included in cost of products sold	1,280	973
Purchases	9,552	6,385
Sales	(9,315)	(6,632)
Settlements	(276)	(428)
Transfers into Level 3	350	539
Transfers out of Level 3	(268)	(125)
Balance at end of period	4,787	3,754
Inventories Carried At Market [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	3,004	2,183
Total increase (decrease) in unrealized gains included in cost of products sold	647	730
Purchases	9,552	6,385
Sales	(9,315)	(6,632)
Settlements	0	0
Transfers into Level 3	327	516
Transfers out of Level 3	(256)	(112)
Balance at end of period	3,959	3,070
Commodity Derivative Contracts Gains [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	460	859
Total increase (decrease) in unrealized gains included in cost of products sold	633	243
Purchases	0	0
Sales	0	0
Settlements	(276)	(428)
Transfers into Level 3	23	23
Transfers out of Level 3	(12)	(13)
Balance at end of period	$ 828	$ 684