v3.20.2
FAIR VALUE MEASUREMENTS - RECONCILIATION FOR ASSETS AND LIABILITIES MEASURE AT FAIR VALUE USING LEVEL 3 (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Total        
Balance at beginning of period $ 450 $ 423 $ 176 $ 193
Purchases 515 315 1,584 1,208
Sales (814) (744) (2,410) (2,077)
Issuances (1) 0 (3) (1)
Settlements 68 160 236 305
Transfers into Level 3 195 213 679 648
Transfers out of Level 3 (281) (67) (461) (165)
Balance at end of period 366 382 366 382
Cost of goods sold        
Total        
Total gains and losses (realized/unrealized) included in cost of goods sold 234 82 565 271
Readily Marketable Inventories        
Readily Marketable Inventories        
Balance at beginning of period 596 772 231 246
Purchases 532 329 1,877 1,654
Sales (814) (744) (2,410) (2,077)
Issuances 0 0 0 0
Settlements 0 0 0 0
Transfers into Level 3 201 213 748 678
Transfers out of Level 3 (320) (68) (566) (181)
Balance at end of period 463 583 463 583
Total        
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities 174 60 334 160
Readily Marketable Inventories | Cost of goods sold        
Readily Marketable Inventories        
Total gains and losses (realized/unrealized) included in cost of goods sold 268 81 583 263
Derivatives, Net        
Derivatives, Net        
Balance at beginning of period (13) (14) (24) (6)
Purchases 2 0 3 0
Sales 0 0 0 0
Issuances (1) 0 (3) (1)
Settlements 15 2 15 2
Transfers into Level 3 (2) 1 8 0
Transfers out of Level 3 (2) 0 (3) 0
Balance at end of period (37) (11) (37) (11)
Total        
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities (37) (1) (33) (10)
Derivatives, Net | Cost of goods sold        
Derivatives, Net        
Total gains and losses (realized/unrealized) included in cost of goods sold (36) 0 (33) (6)
Trade Accounts Receivable/ Payable, Net        
Trade Accounts Receivable/ Payable, Net        
Balance at beginning of period (133) (335) (31) (47)
Purchases (19) (14) (296) (446)
Sales 0 0 0 0
Issuances 0 0 0 0
Settlements 53 158 221 303
Transfers into Level 3 (4) (1) (77) (30)
Transfers out of Level 3 41 1 108 16
Balance at end of period (60) (190) (60) (190)
Total        
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities 2 0 15 0
Trade Accounts Receivable/ Payable, Net | Cost of goods sold        
Trade Accounts Receivable/ Payable, Net        
Total gains and losses (realized/unrealized) included in cost of goods sold $ 2 $ 1 $ 15 $ 14