Consolidated Statements of Earnings and Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement [Abstract]
Tax benefit (expense) on the change in unrealized (gain) loss on marketable securities and cash flow hedges	$ 0	$ 2	$ 0
Tax benefit (expense) on the change in unamortized benefit plan costs	$ 860	$ 823	$ (183)

Tax effects of the gross appreciation or the gross loss in value of the total unsold securities at the end of an accounting period as well as the tax effects of changes in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges after taxes. A cash flow hedge is a hedge of the exposure to variability in the cash flows of a recognized asset or liability or a forecasted transaction that is attributable to a particular risk. The change includes an entity's share of an equity investee's increase (decrease) in deferred hedging gains or losses.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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