Statement of Consolidated Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Statement Of Income And Comprehensive Income [Abstract]
NET INCOME	$ 717	$ 797
Commodity cash flow hedge activity, net of tax:
Reclassification of (gain) loss on settled derivative instruments	6	(34)
Change in fair value of derivative instruments	(8)	1
Commodity cash flow hedge activity, net of tax	(2)	(33)
COMPREHENSIVE INCOME	715	764
Preferred stock dividends	19	19
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON STOCK	$ 696	$ 745

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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- Definition

Tax effect of the income statement impact of the reclassification adjustment of accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges realized in net income. Also includes reclassification adjustments of an entity's share of an equity investee's deferred hedging gain (loss) realized in net income.

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- Definition

Net of tax amount, before reclassification adjustments, of the change in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Also includes an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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+ Details

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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