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Investments - Narrative (Details) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2019 USD ($) | Jun. 30, 2018 USD ($) | Jun. 30, 2019 USD ($) security | Jun. 30, 2018 USD ($) | Dec. 31, 2018 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 |  |  | 75.00% |  |
Percentage (based on fair value) of available for sale fixed maturities that are in an unrealized loss position and rated investment grade |  |  | 91.00% |  |
Other than temporary impairment charges | $ 2 | $ 0 | $ 4 | $ 1 |
Residential MBS |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Non-credit related portion of other-than-temporary impairment charges taken for securities still owned | 130 |  | 130 |  | $ 140
Gross unrealized losses on fixed maturities | (4) |  | (4) |  | (9)
Securities with non-credit other-than-temporary impairment charges |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Gross unrealized gains | 120 |  | 120 |  | 119
Gross unrealized losses | (4) |  | (4) |  | (4)
Fixed maturities |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Gross unrealized losses on fixed maturities | (93) |  | $ (93) |  | $ (603)
Number of available for sale securities in an unrealized loss position | security |  |  | 712 |  |
Other than temporary impairment charges | $ 3 | $ 0 | $ 6 | 1 |
Corporate bonds |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Other than temporary impairment charges |  |  | 5 |  |
Maximum | Residential MBS |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Other than temporary impairment charges |  |  | $ 1 | 1 |
Maximum | Corporate bonds |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Other than temporary impairment charges |  |  |  | $ 1 |

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- Definition Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 12 -Sentence Column A + Details
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