Consolidated Statements of Income (Unaudited) (Parenthetical) (USD $) In Millions	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Consolidated Statements of Income [Abstract]
Net tax effect on loss from discontinued operations	$ 6	$ 17	$ 12	$ 15

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key_NetTaxEffectOnIncomeLossFromDiscontinuedOperations

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xbrli:monetaryItemType

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debit

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duration