Consolidated Statements of Comprehensive Income (unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Statement of Other Comprehensive Income [Abstract]
Net Income	$ 261	$ 263
Other Items of Comprehensive Income	6	3
Less Tax Benefit	(2)	(1)
Other Comprehensive Income	4	2
Comprehensive Income	$ 265	$ 265

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 reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

+ References

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+ Details

- Definition

Tax effect of other comprehensive income (loss) attributable to both parent entity and noncontrolling interest.

+ References

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+ Details