v3.8.0.1
Fair Value of Assets and Liabilities (Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($)
$ in Millions
Dec. 31, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: [1] $ 346,780 $ 321,419
Trading account assets - equity [1] 22,097 21,840
Trading account assets - all other [1] 5,752 5,764
Equity securities, available-for-sale 6,174 9,748
Commercial mortgage and other loans [1] 56,045 52,779
Other long-term investments [1] 12,308 11,283
Short-term investments 6,775 7,508
Other assets [1] 17,035 14,780
Separate account assets 306,617 287,636
TOTAL ASSETS 831,921 783,962
Future policy benefits 257,317 240,908
Other liabilities [1] 16,619 14,739
Total liabilities 777,577 737,874
Netting (9,600) (11,716)
Embedded Derivative, Fair Value of Embedded Derivative, Net Liability 8,748 8,252
Future policy benefits    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Embedded Derivative, Fair Value of Embedded Derivative, Net Liability 8,700 8,200
Embedded Derivative, Fair Value of Embedded Derivative Gross Asset 900 1,200
Embedded Derivative, Fair Value of Embedded Derivative Gross Liability 9,600 9,400
Fair Value, Measurements, Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 346,780 321,419
Trading account assets 27,740 27,454
Equity securities, available-for-sale 6,174 9,748
Commercial mortgage and other loans 593 519
Other long-term investments 272 149
Short-term investments 5,764 7,182
Cash equivalents 8,298 8,306
Other assets 14 0
Separate account assets 280,393 262,017
TOTAL ASSETS 676,028 636,794
Future policy benefits 8,720 8,238
Other liabilities 688 369
Notes issued by consolidated VIEs 1,196 1,839
Total liabilities 10,604 10,446
Asset Netting (9,600) (11,716)
Liability Netting (5,312) (5,945)
Netting (4,288) (5,771)
Fair Value, Measurements, Recurring | All other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Netting (9,601) (11,708)
Fair Value, Measurements, Recurring | Other long-term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Netting 1 (8)
Fair Value, Measurements, Recurring | Other liabilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liability Netting (5,312) (5,945)
Fair Value, Measurements, Recurring | U.S. Treasury securities and obligations of U.S. government authorities and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 26,138 23,784
Trading account assets - debt 328 301
Fair Value, Measurements, Recurring | Obligations of U.S. states and their political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 10,471 9,692
Trading account assets - debt 208 194
Fair Value, Measurements, Recurring | Foreign government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 103,419 96,256
Trading account assets - debt 1,080 941
Fair Value, Measurements, Recurring | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 90,224 81,611
Fair Value, Measurements, Recurring | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 33,734 31,788
Fair Value, Measurements, Recurring | Foreign corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 29,408 28,237
Fair Value, Measurements, Recurring | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 24,227 20,880
Fair Value, Measurements, Recurring | Corporate securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - debt 17,264 17,180
Fair Value, Measurements, Recurring | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 12,233 11,935
Trading account assets - debt 1,485 1,415
Fair Value, Measurements, Recurring | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 13,281 12,704
Trading account assets - debt 2,321 2,062
Fair Value, Measurements, Recurring | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 3,645 4,532
Trading account assets - debt 1,030 1,210
Fair Value, Measurements, Recurring | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - equity 2,798 2,391
Fair Value, Measurements, Recurring | All other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - all other 1,226 1,760
Fair Value, Measurements, Recurring | All other | All other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Netting (9,601) (11,708)
Fair Value, Measurements, Recurring | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Trading account assets 2,071 1,898
Equity securities, available-for-sale 5,344 6,033
Commercial mortgage and other loans 0 0
Other long-term investments 24 44
Short-term investments 3,906 5,623
Cash equivalents 1,900 3,885
Other assets 0 0
Separate account assets 45,397 38,915
TOTAL ASSETS 58,642 56,398
Future policy benefits 0 0
Other liabilities 4 8
Notes issued by consolidated VIEs 0 0
Total liabilities 4 8
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury securities and obligations of U.S. government authorities and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 1 | Obligations of U.S. states and their political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 1 | Foreign government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 1 | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Fair Value, Measurements, Recurring | Level 1 | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Fair Value, Measurements, Recurring | Level 1 | Foreign corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Fair Value, Measurements, Recurring | Level 1 | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Fair Value, Measurements, Recurring | Level 1 | Corporate securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 1 | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 1 | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 1 | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 0 0
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 1 | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - equity 2,015 1,690
Fair Value, Measurements, Recurring | Level 1 | All other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - all other 56 208
Fair Value, Measurements, Recurring | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 337,084 314,562
Trading account assets 33,189 36,029
Equity securities, available-for-sale 540 3,450
Commercial mortgage and other loans 593 519
Other long-term investments 111 106
Short-term investments 1,850 1,558
Cash equivalents 6,398 4,421
Other assets 1 0
Separate account assets 232,874 221,253
TOTAL ASSETS 612,640 581,898
Future policy benefits 0 0
Other liabilities 5,946 6,284
Notes issued by consolidated VIEs 0 0
Total liabilities 5,946 6,284
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury securities and obligations of U.S. government authorities and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 26,086 23,784
Trading account assets - debt 328 301
Fair Value, Measurements, Recurring | Level 2 | Obligations of U.S. states and their political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 10,466 9,687
Trading account assets - debt 208 194
Fair Value, Measurements, Recurring | Level 2 | Foreign government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 103,271 96,132
Trading account assets - debt 857 714
Fair Value, Measurements, Recurring | Level 2 | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 90,115 81,350
Fair Value, Measurements, Recurring | Level 2 | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 31,845 30,434
Fair Value, Measurements, Recurring | Level 2 | Foreign corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 29,329 28,166
Fair Value, Measurements, Recurring | Level 2 | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 23,528 20,393
Fair Value, Measurements, Recurring | Level 2 | Corporate securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - debt 16,712 16,992
Fair Value, Measurements, Recurring | Level 2 | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 5,629 7,591
Trading account assets - debt 697 1,086
Fair Value, Measurements, Recurring | Level 2 | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 13,268 12,690
Trading account assets - debt 2,321 2,061
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 3,547 4,335
Trading account assets - debt 1,029 1,208
Fair Value, Measurements, Recurring | Level 2 | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - equity 274 214
Fair Value, Measurements, Recurring | Level 2 | All other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - all other 10,763 13,259
Fair Value, Measurements, Recurring | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 9,696 6,857
Trading account assets 2,081 1,235
Equity securities, available-for-sale 290 265
Commercial mortgage and other loans 0 0
Other long-term investments 136 7
Short-term investments 8 1
Cash equivalents 0 0
Other assets 13 0
Separate account assets 2,122 1,849
TOTAL ASSETS 14,346 10,214
Future policy benefits 8,720 8,238
Other liabilities 50 22
Notes issued by consolidated VIEs 1,196 1,839
Total liabilities 9,966 10,099
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury securities and obligations of U.S. government authorities and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 52 0
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 3 | Obligations of U.S. states and their political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 5 5
Trading account assets - debt 0 0
Fair Value, Measurements, Recurring | Level 3 | Foreign government bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 148 124
Trading account assets - debt 223 227
Fair Value, Measurements, Recurring | Level 3 | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 109 261
Fair Value, Measurements, Recurring | Level 3 | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 1,889 1,354
Fair Value, Measurements, Recurring | Level 3 | Foreign corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 79 71
Fair Value, Measurements, Recurring | Level 3 | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 699 487
Fair Value, Measurements, Recurring | Level 3 | Corporate securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - debt 552 188
Fair Value, Measurements, Recurring | Level 3 | Asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 6,604 4,344
Trading account assets - debt 788 329
Fair Value, Measurements, Recurring | Level 3 | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 13 14
Trading account assets - debt 0 1
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 98 197
Trading account assets - debt 1 2
Fair Value, Measurements, Recurring | Level 3 | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - equity 509 487
Fair Value, Measurements, Recurring | Level 3 | All other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Trading account assets - all other 8 1
Prudential Netting Agreement | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 2,660 1,456
Prudential Netting Agreement | Fair Value, Measurements, Recurring | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, available-for-sale: 2,660 1,456
Other long-term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value investment measured at NAV per share 1,969 1,579
Separate account assets    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value investment measured at NAV per share $ 26,224 $ 25,619
[1] See Note 5 for details of balances associated with variable interest entities.