Quarterly report pursuant to Section 13 or 15(d)

Subsequent Event (Details)

v2.4.0.8
Subsequent Event (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 6 Months Ended 3 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Jul. 17, 2013
UNITED KINGDOM
Change in Corporate Income Tax Rate [Member]
Sep. 30, 2013
UNITED KINGDOM
Deferred Tax Assets, Remeaurement [Member]
Jul. 17, 2013
Phase One [Member]
UNITED KINGDOM
Change in Corporate Income Tax Rate [Member]
Jul. 17, 2013
Phase Two [Member]
UNITED KINGDOM
Change in Corporate Income Tax Rate [Member]
Subsequent Event [Line Items]                
Reduction in statutory corporate income tax rate (percent)         3.00%   2.00% 1.00%
Statutory Corporate Income Tax Rate         20.00%      
Income tax expense (benefit) $ 1,486 $ 684 $ 1,987 $ 750   $ 1,100