v2.4.0.8
Income Taxes Income Tax Expense & Effective Tax Rate (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Schedule of Income Taxes [Line Items]        
Income Tax Expense (Benefit) $ 63 $ 72 $ 200 $ 182
Effective Income Tax Rate, Percent 16.00% 20.00% 16.00% 16.00%
Change in Enacted Tax Rate, Amount 0 [1] 12 [1] 0 [1] 12 [1]
Cash Taxes Paid     237 215
Her Majesty's Revenue and Customs (HMRC) [Member] | Foreign Tax Authority [Member]
       
Schedule of Income Taxes [Line Items]        
Change in Enacted Tax Rate, Amount   $ 12 [1]   $ 12 [1]
[1] For the three and nine months ended September 30, 2013, the tax expense relates to the enactment of the United Kingdom Finance Act 2013 on July 23, 2013, which provided for a reduction to the corporate income tax rate from 23% to 21% effective April 1, 2014, with a further reduction to 20% effective April 1, 2015. The impact of this legislation was recorded as a discrete item during the third quarter of 2013, and resulted in increased tax expense of approximately $12 million due to the resultant impact on the net deferred tax asset balances.