Investments - Investment Related Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Gain (Loss) on Securities [Line Items]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 1,807	$ 1,253
Debt Securities, Available-for-sale, Realized Gain	164	17
AFS fixed maturity securities
Gross realized losses on investment activity	(134)	(13)
Net realized investment gains on AFS securities	30	4
Debt Securities, Trading, Realized Gain (Loss)	(223)	56
Net recognized investment gains (losses) on equity securities	(50)	18
Derivative gains (losses)	(3,019)	1,692
Provision for Loan, Lease, and Other Losses	284	0
Other gains (losses)	(26)	6
Investment related gains (losses)	$ (3,572)	$ 1,776

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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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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

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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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Line items represent financial 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.

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