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Investments - Narrative (Details) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2017 USD ($) security | Mar. 31, 2016 USD ($) | Dec. 31, 2016 USD ($)
Investment [Line Items] |  |  |
Percentage (based on amount of unrealized loss) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade | 84.00% |  |
Percentage (based on fair value) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade | 89.00% |  |
Other than temporary impairment charges | $ 6 | $ 52 |
Average life of ABS | 5 years |  |
Average life of MBS | 4 years 6 months |  |
Residential MBS |  |  |
Investment [Line Items] |  |  |
Non-credit related portion of other-than-temporary impairment charges taken for securities still owned | $ 170 |  | $ 189
Fixed maturities, Gross Unrealized, Losses | (11) |  | (13)
Securities with non-credit other-than-temporary impairment charges |  |  |
Investment [Line Items] |  |  |
Gross Unrealized, Gains | 128 |  | 130
Gross Unrealized, Losses | (2) |  | (3)
Fixed maturities |  |  |
Investment [Line Items] |  |  |
Fixed maturities, Gross Unrealized, Losses | $ (165) |  | (245)
Number of available for sale securities in an unrealized loss position | security | 1,048 |  |
Other than temporary impairment charges | $ 0 | $ 16 |
Common stocks |  |  |
Investment [Line Items] |  |  |
Number of available for sale securities in an unrealized loss position | security | 17 |  |
Other than temporary impairment charges | $ 3 |  |
Equity securities, Gross Unrealized, Losses | $ (21) |  | (23)
Preferred stocks |  |  |
Investment [Line Items] |  |  |
Number of available for sale securities in an unrealized loss position | security | 13 |  |
Other than temporary impairment charges | $ 6 |  |
Equity securities, Gross Unrealized, Losses | $ (3) |  | $ (7)
Number of available for sale securities in an unrealized loss position for twelve months or longer | Common stocks |  |  |
Investment [Line Items] |  |  |
Number of available for sale securities in an unrealized loss position | security | 0 |  |
Number of available for sale securities in an unrealized loss position for twelve months or longer | Preferred stocks |  |  |
Investment [Line Items] |  |  |
Number of available for sale securities in an unrealized loss position | security | 1 |  |
Maximum | Fixed maturities — all other |  |  |
Investment [Line Items] |  |  |
Other than temporary impairment charges | $ 1 |  |
Maximum | Residential MBS |  |  |
Investment [Line Items] |  |  |
Other than temporary impairment charges | 1 |  |
Maximum | Corporate bonds |  |  |
Investment [Line Items] |  |  |
Other than temporary impairment charges | $ 1 |  |

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