Statement of Consolidated Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Statement of Consolidated Comprehensive Income [Abstract]
NET INCOME	$ 797	$ 1,134
Commodity cash flow hedge activity, net of tax:
Reclassification of (gain) loss on settled derivative instruments	(34)	(4)
Change in fair value of derivative instruments	1	(302)
Derivative hedge ineffectiveness reclassified into earnings		2
Commodity cash flow hedge activity, net of tax	(33)	(304)
COMPREHENSIVE INCOME	764	830
Preferred stock dividends	19	19
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON STOCK	$ 745	$ 811

Comprehensive income net of tax attributable to common stock.

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The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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Equity impact of stock dividends for preferred shareholders declared by an entity during the period. This element includes paid and unpaid dividends declared during the period.

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Tax effect on reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.

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Change in accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges, net of tax effect. The after tax effect change includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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