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Deferred Policy Acquisition Costs - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019
Deferred Policy Acquisition Costs Disclosures [Abstract] |  |
Accumulated amortization of present value of future profits | $ 160 | $ 154
Approximate annual rate of decrease in present value of future profits during next five years | 14.29% |

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