SUPPLEMENTARY OIL AND GAS INFORMATION (UNAUDITED) (Schedule of Standardized Measure of Future Net Cash Flows) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Future cash inflows	$ 38,901
Future production expense	(12,774)
Future development costs	(6,480)	[1]
Future income tax expense	(4,935)
Future net cash flows	14,712
Discounted at 10% per year	(5,295)
Standardized Measure	9,417
Asset Retirement Obligation	2,328		1,146	921	856
Oil and Gas Operations Segment [Member]
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items]
Asset Retirement Obligation	$ 1,800

[1] Included estimated asset retirement costs of $1.8 billion.