v3.8.0.1
Value of Business Acquired (Balance of and Changes in VOBA) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Balance, beginning of year $ 2,314 $ 2,828 $ 2,836
Amortization—Impact of assumption and experience unlocking and true-ups (56) (246) 128
Amortization—All other (311) (351) (385)
Change in unrealized investment gains and losses (456) (112) 214
Interest 75 81 86
Foreign currency translation 25 114 (57)
Other 0 0 6
Balance, end of year 1,591 $ 2,314 $ 2,828
CIGNA      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Balance, end of year $ 223    
Weighted Average Useful Life 12 years    
Interest accrual rates 6.40% 6.40% 6.40%
Prudential Annuities Holding Company      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Balance, end of year $ 38    
Weighted Average Useful Life 5 years    
Interest accrual rates 5.96% 6.00% 6.05%
Gibraltar Life      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Balance, end of year $ 1,178    
Weighted Average Useful Life 9 years    
Gibraltar Life | Minimum      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Interest accrual rates 1.28% 1.28% 1.28%
Gibraltar Life | Maximum      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Interest accrual rates 2.87% 2.87% 2.87%
Aoba Life      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Balance, end of year $ 0    
Weighted Average Useful Life 7 years    
Interest accrual rates 2.60% 2.60% 2.60%
Hartford Life Business      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Balance, end of year $ 145    
Weighted Average Useful Life 9 years    
Hartford Life Business | Minimum      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Interest accrual rates 3.00% 3.00% 3.00%
Hartford Life Business | Maximum      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Interest accrual rates 6.17% 6.17% 6.17%
Gibraltar BSN Life Berhad      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Balance, end of year $ 7    
Weighted Average Useful Life 8 years    
Gibraltar BSN Life Berhad | Minimum      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Interest accrual rates 4.07% 4.07% 4.07%
Gibraltar BSN Life Berhad | Maximum      
Movement in Present Value of Future Insurance Profits [Roll Forward]      
Interest accrual rates 5.51% 5.51% 5.51%