FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - RECONCILIATION FOR ASSETS AND LIABILITIES MEASURE AT FAIR VALUE USING LEVEL 3 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Balance at beginning of period	$ 368	$ 220
Purchases	885	1,318
Sales	(1,400)	(1,982)
Issuances	(1)	(328)
Settlements	73	391
Transfers into Level 3	678	646
Transfers out of Level 3	(559)	(415)
Balance at end of period	142	368
Cost of goods sold
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Total gains and losses (realized/unrealized) included in cost of goods sold	98	518
Changes in unrealized gains and (losses) relating to assets and liabilities	(48)	22
Derivatives, Net
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Balance at beginning of period	167	(2)
Purchases		1
Issuances	(1)	(1)
Settlements	(133)	(219)
Transfers into Level 3	(4)	5
Transfers out of Level 3	8	(6)
Balance at end of period	(51)	167
Derivatives, Net | Cost of goods sold
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Total gains and losses (realized/unrealized) included in cost of goods sold	(88)	389
Changes in unrealized gains and (losses) relating to assets and liabilities	(1)	37
Readily Marketable Inventories
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Balance at beginning of period	245	255
Purchases	1,107	1,329
Sales	(1,400)	(1,982)
Transfers into Level 3	760	845
Transfers out of Level 3	(637)	(337)
Balance at end of period	237	245
Readily Marketable Inventories | Cost of goods sold
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Total gains and losses (realized/unrealized) included in cost of goods sold	162	135
Changes in unrealized gains and (losses) relating to assets and liabilities	(41)	(13)
Trade Accounts Receivable/Payable, Net
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Balance at beginning of period	(44)	(33)
Purchases	(222)	(12)
Issuances		(327)
Settlements	206	610
Transfers into Level 3	(78)	(204)
Transfers out of Level 3	70	(72)
Balance at end of period	(44)	(44)
Trade Accounts Receivable/Payable, Net | Cost of goods sold
Reconciliation of Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)
Total gains and losses (realized/unrealized) included in cost of goods sold	24	(6)
Changes in unrealized gains and (losses) relating to assets and liabilities	$ 1	$ (2)