v3.21.1
FAIR VALUE MEASUREMENTS - RECONCILIATION FOR ASSETS AND LIABILITIES MEASURE AT FAIR VALUE USING LEVEL 3 (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Total    
Balance at beginning of period $ 191 $ 176
Purchases 358 443
Sales (762) (627)
Issuances (2) (2)
Settlements 34 43
Transfers into Level 3 262 215
Transfers out of Level 3 122 (88)
Balance at end of period 348 342
Cost of goods sold    
Total    
Total gains and losses (realized/unrealized) included in cost of goods sold 145 182
Readily Marketable Inventories    
Readily Marketable Inventories    
Balance at beginning of period 208 231
Purchases 540 678
Sales (762) (627)
Issuances 0 0
Settlements 0 0
Transfers into Level 3 446 271
Transfers out of Level 3 (57) (98)
Balance at end of period 629 619
Total    
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities 130 73
Readily Marketable Inventories | Cost of goods sold    
Readily Marketable Inventories    
Total gains and losses (realized/unrealized) included in cost of goods sold 254 164
Derivatives, Net    
Derivatives, Net    
Balance at beginning of period (8) (24)
Purchases 3 1
Sales 0 0
Issuances (2) (2)
Settlements 34 (18)
Transfers into Level 3 (25) 3
Transfers out of Level 3 42 10
Balance at end of period (68) (16)
Total    
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities (125) 13
Derivatives, Net | Cost of goods sold    
Derivatives, Net    
Total gains and losses (realized/unrealized) included in cost of goods sold (112) 14
Trade Accounts Payable Net    
Trade Accounts Receivable/ Payable, Net    
Balance at beginning of period (9) (31)
Purchases (185) (236)
Sales 0 0
Issuances 0 0
Settlements 0 61
Transfers into Level 3 (159) (59)
Transfers out of Level 3 137 0
Balance at end of period (213) (261)
Total    
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities 3 5
Trade Accounts Payable Net | Cost of goods sold    
Trade Accounts Receivable/ Payable, Net    
Total gains and losses (realized/unrealized) included in cost of goods sold $ 3 $ 4