Provision for Income Taxes Reconciliation of Unrecognized Tax Benefits Table (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 58	$ 38
Additions based on tax positions related to the current year	4	4
Additions for tax positions of prior years	18	22
Reductions for tax positions of prior years	(2)	(6)
Settlement with taxing authorities	(12)	0
Balance at end of period	$ 66	$ 58

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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