v3.8.0.1
Derivative Instruments (Gross Notional Amount and Fair Value of Derivatives Contracts) (Details) - USD ($)
$ in Millions
Dec. 31, 2017
Dec. 31, 2016
Derivative [Line Items]    
Notional $ 392,399 $ 366,091
Assets 10,807 13,088
Liabilities (5,955) (6,290)
Net Embedded Derivative Liability 8,748 8,252
Derivatives Designated as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 21,481 16,021
Assets 1,037 1,976
Liabilities (831) (166)
Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 370,918 350,070
Assets 9,770 11,112
Liabilities (5,124) (6,124)
Interest Rate Swaps | Derivatives Designated as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 3,204 1,117
Assets 271 17
Liabilities (88) (111)
Interest Rate Swaps | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 158,552 162,131
Assets 7,958 8,969
Liabilities (3,509) (4,274)
Interest Rate Futures | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 23,792 31,183
Assets 25 55
Liabilities (1) (1)
Interest Rate Options | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 18,456 13,290
Assets 167 289
Liabilities (203) (132)
Interest Rate Forwards | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 1,498 321
Assets 6 0
Liabilities (2) (1)
Foreign Currency Forwards | Derivatives Designated as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 545 167
Assets 0 3
Liabilities (8) (1)
Foreign Currency Forwards | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 23,905 21,042
Assets 164 372
Liabilities (254) (892)
Foreign Currency Options | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 59 93
Assets 0 0
Liabilities 0 0
Foreign Currency Swaps | Derivatives Designated as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 17,732 14,737
Assets 766 1,956
Liabilities (735) (54)
Foreign Currency Swaps | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 13,777 12,336
Assets 822 1,218
Liabilities (414) (311)
Credit Default Swaps | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 1,314 918
Assets 21 1
Liabilities (5) (25)
Equity Futures | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 710 1,371
Assets 2 0
Liabilities (2) (5)
Equity Options | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 36,007 12,020
Assets 588 102
Liabilities (364) (93)
Total Return Swaps | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 15,558 18,167
Assets 17 101
Liabilities (369) (390)
Commodity Futures | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 0 1
Assets 0 0
Liabilities 0 0
Synthetic GICs | Derivatives Not Qualifying as Hedge Accounting Instruments:    
Derivative [Line Items]    
Notional 77,290 77,197
Assets 0 5
Liabilities $ (1) $ 0