Reinsurance - Effects of Reinsurance (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Premiums Earned, Net [Abstract]    
Ceded $ 130 $ 141
Net 7,402 6,676
Reinsurance Recoveries [Abstract]    
Reinsurance recoveries 159 181
Individual Life Insurance And Annuity Business Sold [Member]    
Premiums Earned, Net [Abstract]    
Ceded 41 45
Reinsurance Recoveries [Abstract]    
Reinsurance recoveries 86 99
Other Subsegments [Member]    
Premiums Earned, Net [Abstract]    
Ceded 89 96
Reinsurance Recoveries [Abstract]    
Reinsurance recoveries $ 73 $ 82