Income Taxes (Details 3) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Unrecognized Tax Benefits Rollforward (Table Amounts) [Abstract]
Unrecognized tax benefits at beginning of the year	$ 223	$ 210	$ 241
Additions based on tax positions related to the current year	35	52	62
Additions for tax positions of prior years	2	17	9
Reductions for tax positions of prior years	(40)	(10)	(47)
Settlements with taxing authorities	(84)	0	(14)
Other, net	(1)	(46)	(41)
Net change in unrecognized tax benefits	(88)	13	(31)
Unrecognized tax benefits at end of the year	$ 135	$ 223	$ 210

Unrecognized Tax Benefits, Other

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

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- Definition

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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- Definition

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

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Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

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