Recent Accounting Pronouncements (Details) $ in Millions	12 Months Ended
Dec. 31, 2014 USD ($)
Reclassification To Long-Term Debt [Member]
Reclassification adjustment	$ 93
Reclassification To Deferred Income Taxes [Member]
Reclassification adjustment	$ 71

The amount of a reclassification adjustment made to prior period financial statement amounts.

No definition available.

Name:	us-gaap_PriorPeriodReclassificationAdjustment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration