v2.4.0.8
Income Taxes (Details) (USD $)
In Millions, unless otherwise specified
1 Months Ended 6 Months Ended 6 Months Ended 6 Months Ended
May 31, 2013
subsidiary
Jun. 30, 2013
jurisdiction
Jun. 30, 2012
Dec. 31, 2012
Jun. 30, 2013
Minimum
Jun. 30, 2013
Maximum
Jun. 30, 2013
Norway Tax Assessments Prior to 2012
item
subsidiary
employee
Nov. 30, 2012
Norway Tax Assessments Prior to 2012
Jun. 30, 2013
Norway Tax Assessments 2012
advisor
subsidiary
Jun. 30, 2013
2008 and 2009 federal income tax returns
Dec. 31, 2012
2008 and 2009 federal income tax returns
Components of provision (benefit) for income taxes                      
Annual effective tax rate (as a percent)   21.60% 24.60%                
Unrecognized tax benefits                      
Unrecognized tax benefits, excluding interest and penalties   $ 370   $ 382              
Interest and penalties   185   199              
Unrecognized tax benefits, including interest and penalties   555   581              
Current tax benefit recognized from the settlement of dispute with tax authorities and lapse of applicable statutes of limitations   49                  
Reasonably possible percentage that unrecognized tax benefits could decrease within next twelve months, Maximum   13.00%                  
Reasonably possible percentage that unrecognized tax benefits could increase within next twelve months, Maximum   5.00%                  
Income Tax Examination                      
Range of tax returns are subject to examination         3 years 6 years          
Number of jurisdictions with extensions beyond statute of limitations   2                  
Maximum number of years agreed to extensions beyond the statute of limitations   18 years                  
Additional tax, excluding interest and penalties payable on settlement with the U.S. tax authorities                     36
Net adjustments of additional taxes, excluding interest and penalties, related to assessments on 2008 and 2009 U.S. federal income tax returns                   363  
Norway tax assessment due to migration of subsidiary, including interest             117 117      
Norway tax assessment due to 2001 dividend payment, including interest             70        
Norway tax assessment due to foreign exchange deductions and dividend withholding taxes, including interest             7        
Guarantee amount for tax assessment related to the migration of subsidiary             119        
Norway tax additional financial security, including interest and penalties             220        
Percentage of penalties to be assessed by Norway tax authorities             60.00%        
Number of appeals to tax assessments expected to be filed or filed             2        
Number of subsidiaries against which notification of criminal charges are issued             2   2    
Number of subsidiaries against which notification of criminal charges are extending                 2    
Number of employees of former external advisors indicted             2   2    
Financial claim issued by the Norweigian authorities supplementing the criminal indictments                 313    
Financial claim dropped by the Norwegian authorities 313                    
Number of subsidiaries against which notification of criminal charges are dropped 1                    
Brazil tax assessment for income tax returns 2000 to 2004   97                  
Percentage of penalties to be assessed by Brazil tax authorities   75.00%                  
Brazil tax assessment penalty   73                  
Brazil tax assessment interest   $ 155