Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Intangible assets with definite lives
Gross carrying amount	$ 79	$ 79
Accumulated amortization	(53)	(47)
Net	26	32
Customer relationships [Member]
Intangible assets with definite lives
Gross carrying amount	70	70
Accumulated amortization	(46)	(41)
Net	24	29
Other intangible assets [Member]
Intangible assets with definite lives
Gross carrying amount	9	9
Accumulated amortization	(7)	(6)
Net	$ 2	$ 3

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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