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Derivatives - Gain (loss) included in the Statement of Earnings for changes in the fair value of derivatives that do not qualify for hedge accounting (Details) - Not Designated as Hedging Instrument - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
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Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018
Derivative, Gain (Loss) on Derivative, Net [Abstract] |  |  |  |  |
Derivative |  | $ (98) | $ (36) | $ (188) | $ (15)
MBS with embedded derivatives | Realized gains (losses) on securities |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net [Abstract] |  |  |  |  |
Derivative |  | 6 | (1) | 12 | (5)
Public company warrants | Realized gains (losses) on securities |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net [Abstract] |  |  |  |  |
Derivative |  | 0 | 0 | 0 | (1)
Fixed-indexed and variable-indexed annuities (embedded derivative) | Annuity benefits |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net [Abstract] |  |  |  |  |
Derivative | [1] | (251) | (126) | (713) | (63)
Equity index call options | Annuity benefits |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net [Abstract] |  |  |  |  |
Derivative |  | 148 | 90 | 514 | 52
Equity index put options | Annuity benefits |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net [Abstract] |  |  |  |  |
Derivative |  | 0 | 0 | 1 | 0
Reinsurance contracts (embedded derivative) | Net investment income |  |  |  |  |
Derivative, Gain (Loss) on Derivative, Net [Abstract] |  |  |  |  |
Derivative |  | $ (1) | $ 1 | $ (2) | $ 2
[1] | The change in fair value of the embedded derivative includes a loss related to the unlocking of actuarial assumptions of $44 million in the second quarter of 2018.

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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
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