Investments - Investment Related Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AFS fixed maturity securities
Gross realized gains on investment activity	$ 192	$ 47	$ 424	$ 120
Gross realized losses on investment activity	(178)	(21)	(378)	(38)
Net realized investment gains on AFS securities	14	26	46	82
Net recognized investment gains (losses) on trading securities	24	48	(8)	183
Net recognized investment gains (losses) on equity securities	12	(4)	(8)	15
Derivative gains	1,648	620	959	3,493
Provision for Loan, Lease, and Other Losses	84	0	(205)	0
Other gains (losses)	15	(25)	(11)	(19)
Investment related gains (losses)	1,797	665	773	3,754
Proceeds from Sale of Debt Securities, Available-for-sale	$ 3,940	$ 852	$ 7,525	$ 4,063

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Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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Amount of gain (loss) included in earnings for investments classified as other.

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Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

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