v3.8.0.1
Reinsurance (Reinsurance Recoverable) (Details) - USD ($)
$ in Millions
Dec. 31, 2017
Dec. 31, 2016
Effects of Reinsurance [Line Items]    
Total reinsurance recoverables $ 5,159 $ 4,211
Individual and group annuities    
Effects of Reinsurance [Line Items]    
Total reinsurance recoverables 698 658
Life insurance    
Effects of Reinsurance [Line Items]    
Total reinsurance recoverables 4,290 3,388
Other reinsurance    
Effects of Reinsurance [Line Items]    
Total reinsurance recoverables 171 165
CIGNA | Individual and group annuities    
Effects of Reinsurance [Line Items]    
Total reinsurance recoverables 682 656
Hartford Life Business | Life insurance    
Effects of Reinsurance [Line Items]    
Total reinsurance recoverables 2,145 2,049
Reinsurance Payable 1,301 1,205
Union Hamilton | Individual and group annuities    
Effects of Reinsurance [Line Items]    
Total reinsurance recoverables $ 13 $ 0