v2.4.0.8
Share-Based Compensation Share-Based Compensation - Performance Share Unit Breakout (Details) (USD $)
In Millions, except Share data, unless otherwise specified
3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Performance Shares [Member]
Jun. 30, 2013
Performance Shares [Member]
Jun. 30, 2014
Performance Shares [Member]
Jun. 30, 2013
Performance Shares [Member]
Jun. 30, 2014
Year of 2012 [Member]
Performance Shares [Member]
Jun. 30, 2013
Year of 2012 [Member]
Performance Shares [Member]
Jun. 30, 2014
Payable 2015 [Member]
Year of 2012 [Member]
Performance Shares [Member]
Dec. 31, 2012
Payable 2015 [Member]
Year of 2012 [Member]
Performance Shares [Member]
Jun. 30, 2014
Payable 2016 [Member]
Year of 2013 [Member]
Performance Shares [Member]
Dec. 31, 2012
Payable 2016 [Member]
Year of 2013 [Member]
Performance Shares [Member]
Jun. 30, 2014
Payable 2017 [Member]
Year of 2014 [Member]
Performance Shares [Member]
Dec. 31, 2012
Payable 2017 [Member]
Year of 2014 [Member]
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                                
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized                     884,507   1,701,941   658,059  
Allocated Share-based Compensation Expense $ 29 $ 36 $ 56 $ 88 $ 14 $ 5 $ 14 $ 15 $ 11 $ 2            
Fair Value of Share Based Award                     31 23 66 35 20 17
Share Based Award Liability, Current                     $ 31   $ 59   $ 9