Income Taxes (Details 6) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of unrecognized income tax benefits
Unrecognized tax benefits, beginning of year	$ 0us-gaap_UnrecognizedTaxBenefits	$ 2us-gaap_UnrecognizedTaxBenefits	$ 0us-gaap_UnrecognizedTaxBenefits
Additions for income tax positions related to prior year	0	0	2
Reductions for income tax positions related to settlements	0	(2)	0
Unrecognized tax benefits, end of year	0us-gaap_UnrecognizedTaxBenefits	0us-gaap_UnrecognizedTaxBenefits	2us-gaap_UnrecognizedTaxBenefits
Unrecognized tax benefits that, if recognized, would impact the effective tax rate	0	0	2
Recognized interest and penalties			(5)
Maximum
Reconciliation of unrecognized income tax benefits
Recognized interest and penalties	(1)	(1)
Accrued interest and penalties	$ 1	$ 1	$ 1

The amount of estimated penalties and interest accrued as of the balance sheet date arising from income tax examinations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

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The sum of the amounts of estimated penalties and interest recognized in the period arising from income tax examinations.

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

+ References

Reference 1: 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

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

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-Name Accounting Standards Codification

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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