v3.8.0.1

Investments (Fair Value and Losses by Investment Category and Length of Time in a Loss Position) (Details) - USD ($) $ in Millions | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Fixed maturities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | $ 27,635 | $ 68,613
Less than twelve months, Gross Unrealized Loss | 333 | 3,205
Twelve months or more, Fair Value | 28,336 | 12,250
Twelve months or more, Gross Unrealized Losses | 1,443 | 1,420
Total, Fair Value | 55,971 | 80,863
Total, Gross Unrealized Losses | 1,776 | 4,625
Fair Value not reflected in AOCI, held-to-maturity securities | 12 | 12
Gross Unrealized Losses not reflected in AOCI, held-to-maturity securities | 1 | 1
Fixed maturities | U.S. Treasury securities and obligations of U.S. government authorities and agencies |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 3,450 | 9,345
Less than twelve months, Gross Unrealized Loss | 28 | 1,001
Twelve months or more, Fair Value | 6,391 | 0
Twelve months or more, Gross Unrealized Losses | 318 | 0
Total, Fair Value | 9,841 | 9,345
Total, Gross Unrealized Losses | 346 | 1,001
Fixed maturities | Obligations of U.S. states and their political subdivisions |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 44 | 2,677
Less than twelve months, Gross Unrealized Loss | 0 | 79
Twelve months or more, Fair Value | 287 | 19
Twelve months or more, Gross Unrealized Losses | 6 | 5
Total, Fair Value | 331 | 2,696
Total, Gross Unrealized Losses | 6 | 84
Fixed maturities | Foreign government bonds |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 4,417 | 6,076
Less than twelve months, Gross Unrealized Loss | 55 | 325
Twelve months or more, Fair Value | 2,937 | 310
Twelve months or more, Gross Unrealized Losses | 238 | 29
Total, Fair Value | 7,354 | 6,386
Total, Gross Unrealized Losses | 293 | 354
Fixed maturities | U.S. corporate public securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 7,914 | 22,803
Less than twelve months, Gross Unrealized Loss | 110 | 905
Twelve months or more, Fair Value | 6,831 | 2,943
Twelve months or more, Gross Unrealized Losses | 304 | 327
Total, Fair Value | 14,745 | 25,746
Total, Gross Unrealized Losses | 414 | 1,232
Fixed maturities | U.S. corporate private securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 4,596 | 7,797
Less than twelve months, Gross Unrealized Loss | 76 | 228
Twelve months or more, Fair Value | 2,009 | 1,296
Twelve months or more, Gross Unrealized Losses | 93 | 80
Total, Fair Value | 6,605 | 9,093
Total, Gross Unrealized Losses | 169 | 308
Fixed maturities | Foreign corporate public securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 2,260 | 5,196
Less than twelve months, Gross Unrealized Loss | 21 | 162
Twelve months or more, Fair Value | 1,678 | 1,047
Twelve months or more, Gross Unrealized Losses | 78 | 143
Total, Fair Value | 3,938 | 6,243
Total, Gross Unrealized Losses | 99 | 305
Fixed maturities | Foreign corporate private securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 1,213 | 6,557
Less than twelve months, Gross Unrealized Loss | 20 | 350
Twelve months or more, Fair Value | 5,339 | 4,916
Twelve months or more, Gross Unrealized Losses | 317 | 799
Total, Fair Value | 6,552 | 11,473
Total, Gross Unrealized Losses | 337 | 1,149
Fixed maturities | Commercial mortgage-backed securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 2,593 | 4,879
Less than twelve months, Gross Unrealized Loss | 17 | 123
Twelve months or more, Fair Value | 2,212 | 60
Twelve months or more, Gross Unrealized Losses | 74 | 2
Total, Fair Value | 4,805 | 4,939
Total, Gross Unrealized Losses | 91 | 125
Fixed maturities | Asset-backed securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 564 | 2,357
Less than twelve months, Gross Unrealized Loss | 2 | 20
Twelve months or more, Fair Value | 366 | 1,581
Twelve months or more, Gross Unrealized Losses | 8 | 33
Total, Fair Value | 930 | 3,938
Total, Gross Unrealized Losses | 10 | 53
Fixed maturities | Residential mortgage-backed securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 584 | 926
Less than twelve months, Gross Unrealized Loss | 4 | 12
Twelve months or more, Fair Value | 286 | 78
Twelve months or more, Gross Unrealized Losses | 7 | 2
Total, Fair Value | 870 | 1,004
Total, Gross Unrealized Losses | 11 | 14
Equity securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than twelve months, Fair Value | 358 | 637
Less than twelve months, Gross Unrealized Loss | 28 | 41
Twelve months or more, Fair Value | 0 | 12
Twelve months or more, Gross Unrealized Losses | 1 | 1
Total, Fair Value | 358 | 649
Total, Gross Unrealized Losses | $ 29 | $ 42

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