Severance (Details) (Employee severance, USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2012
Employee severance
Restructuring reserve
Balance at the beginning of the period	$ 29
Accrued to expense	58
Payments, net	(74)
Reversals and adjustments	(1)
Balance at the end of the period	$ 12

Amount charged against earnings in the period for incurred and estimated costs associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding asset retirement obligations.

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Amount of any reversal and other adjustment made during the period to the amount of a previously accrued liability for a specified type of restructuring cost, excluding adjustments for costs incurred during the period, costs settled during the period, and foreign currency translation adjustments.

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- Definition

Amount of cash paid in the period to fully or partially settle a specified, previously accrued type of restructuring cost.

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