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Investments (Fair Value Below Amortized Cost of Gross Unrealized Losses for Fixed Maturity Securities) (Details) - USD ($) $ in Millions | 6 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Jun. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Gross unrealized losses with number of securities [Line Items] |  |  |
Document Period End Date | Jun. 30, 2021 |  |
Gross Unrealized Losses | $ 267 | $ 197 |
% of Total | 100.00% |  | 100.00%
Less than 20% |  |  |
Gross unrealized losses with number of securities [Line Items] |  |  |
Gross Unrealized Losses | $ 213 | 133 |
% of Total | 79.80% |  | 67.50%
20% or more for less than six months |  |  |
Gross unrealized losses with number of securities [Line Items] |  |  |
Gross Unrealized Losses | $ 2 | 42 |
% of Total | 0.70% |  | 21.30%
20% or more for six months or greater |  |  |
Gross unrealized losses with number of securities [Line Items] |  |  |
Gross Unrealized Losses | $ 52 | $ 22 |
% of Total | 19.50% |  | 11.20%

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- Definition For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD. + References No definition available. + Details
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