INVESTMENTS AND RELATED-PARTY TRANSACTIONS (Details) (USD $) Share data in Millions, unless otherwise specified	1 Months Ended		12 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
EQUITY INVESTMENTS
Pre-tax gain on sale of equity investment			2,505,000,000	1,175,000,000
RELATED-PARTY TRANSACTIONS
Sales to related parties			835,000,000	663,000,000	419,000,000
Purchases from related parties			6,000,000		8,000,000
Services to related parties			27,000,000	30,000,000	17,000,000
Advances and amounts due from related parties			26,000,000	67,000,000	25,000,000
Amounts due to related parties			15,000,000	3,000,000	129,000,000
Equity Method Investments
Equity method investment amounts			1,171,000,000	1,459,000,000	1,894,000,000
Equity investments dividends paid			396,000,000	447,000,000	526,000,000
Excess of investments in equity investees over the underlying equity in net assets			632,000,000
Excess of investments in equity investees over the underlying equity in net assets, which represents goodwill			546,000,000
Equity-method investments financial information summarized by Income Statement line item
Revenues			3,090,000,000	3,373,000,000	2,667,000,000
Costs and expenses			2,774,000,000	2,987,000,000	2,310,000,000
Net income			316,000,000	386,000,000	357,000,000
Equity-method investments financial information summarized by Balance Sheet line item
Current assets			1,127,000,000	1,813,000,000
Non-current assets			2,925,000,000	4,412,000,000
Current liabilities			771,000,000	1,308,000,000
Long-term debt			1,701,000,000	2,506,000,000
Other non-current liabilities			83,000,000	163,000,000
Stockholders' equity			1,498,000,000	2,248,000,000
General Partner of Plains All American Pipeline,L.P
EQUITY INVESTMENTS
Ownership interest (as a percent)			13.00%
Proceeds from sale of investment	1,700,000,000	1,400,000,000
Pre-tax gain on sale of equity investment	1,400,000,000	1,000,000,000
RELATED-PARTY TRANSACTIONS
Sales to related party (as a percent)			46.00%	72.00%	80.00%
California Resource Corporation
EQUITY INVESTMENTS
Investment recorded as available for sale asset, shares owned			71.5
Interest in investment recorded as available for sale asset (as a percent)			18.70%
Value of investment recorded as available for sale asset			394,000,000
Other than temperary loss			553,000,000
Dolphin Energy
EQUITY INVESTMENTS
Equity method investment ownership percentage			24.50%
Ownership interest (as a percent)			24.50%
Number of separate economic interests comprising investment in unconsolidated affiliate			2