Fair Value Measurements - Roll Forward of Assets Measured at Fair Value on a Recurring Basis Using Unobservable Inputs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 493
Balance at end of period		$ 493
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	3,458	3,444
Increase (decrease) in unrealized gains included in Cost of products sold	54	1,707
Increase (decrease) in unrealized losses included in Cost of products sold	0	0
Realized increases (decreases) included in Cost of products sold	28	(51)
Purchases	18,640	16,296
Sales	(17,761)	(16,609)
Settlements	(1,106)	(1,369)
Transfers into Level 3	1,857	1,657
Transfers out of Level 3	(1,985)	(1,617)
Balance at end of period	3,185	3,458
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	493	558
Increase (decrease) in unrealized gains included in Cost of products sold	0	0
Increase (decrease) in unrealized losses included in Cost of products sold	865	1,141
Realized increases (decreases) included in Cost of products sold	(15)	(29)
Purchases	21	79
Sales	(91)	(81)
Settlements	(985)	(1,142)
Transfers into Level 3	72	69
Transfers out of Level 3	(31)	(102)
Balance at end of period	$ 329	$ 493
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Cost of products sold	Cost of products sold
Level 3 | Inventory-related Payables
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 88	$ 101
Increase (decrease) in unrealized gains included in Cost of products sold	0	0
Increase (decrease) in unrealized losses included in Cost of products sold	13	17
Realized increases (decreases) included in Cost of products sold	(15)	(29)
Purchases	21	79
Sales	(91)	(81)
Settlements	0	0
Transfers into Level 3	0	1
Transfers out of Level 3	0	0
Balance at end of period	16	88
Level 3 | Commodity Derivative Contracts Losses
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	405	457
Increase (decrease) in unrealized gains included in Cost of products sold	0	0
Increase (decrease) in unrealized losses included in Cost of products sold	852	1,124
Realized increases (decreases) included in Cost of products sold	0	0
Purchases	0	0
Sales	0	0
Settlements	(985)	(1,142)
Transfers into Level 3	72	68
Transfers out of Level 3	(31)	(102)
Balance at end of period	313	405
Level 3 | Inventories Carried at Market
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	3,031	2,713
Increase (decrease) in unrealized gains included in Cost of products sold	(1,021)	697
Increase (decrease) in unrealized losses included in Cost of products sold	0	0
Realized increases (decreases) included in Cost of products sold	28	(51)
Purchases	18,640	16,296
Sales	(17,761)	(16,609)
Settlements	0	0
Transfers into Level 3	1,616	1,416
Transfers out of Level 3	(1,860)	(1,431)
Balance at end of period	2,673	3,031
Level 3 | Commodity Derivative Contracts Gains
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	427	731
Increase (decrease) in unrealized gains included in Cost of products sold	1,075	1,010
Increase (decrease) in unrealized losses included in Cost of products sold	0	0
Realized increases (decreases) included in Cost of products sold	0	0
Purchases	0	0
Sales	0	0
Settlements	(1,106)	(1,369)
Transfers into Level 3	241	241
Transfers out of Level 3	(125)	(186)
Balance at end of period	$ 512	$ 427