Quarterly report pursuant to Section 13 or 15(d)

Subsequent Event (Details)

v2.4.0.6
Subsequent Event (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended 3 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Jul. 17, 2012
United Kingdom
Change in Corporate Income Tax Rate [Member]
Sep. 30, 2012
United Kingdom
Deferred Tax Assets, Remeasurement [Member]
Jul. 17, 2012
Aggregate reduction effective April 1, 2013
United Kingdom
Change in Corporate Income Tax Rate [Member]
Jul. 17, 2012
Aggregate reduction effective April 1, 2012
United Kingdom
Change in Corporate Income Tax Rate [Member]
Subsequent Event [Line Items]                
Reduction in Statutory Corporate Income Tax Rate         2.00%   2.00% 1.00%
Statutory Corporate Income Tax Rate         23.00%      
Income tax expense (benefit) $ 684 $ (4,049) $ 750 $ (3,318)   $ 800