Investments (Net Investment Gains Losses - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 177	$ (153)	$ 84
Net investment gains (losses)	1,529	(110)	444
Gain (Loss) on Termination of Lease		87
Gain (Loss) on Sale of Investments	131	198	(142)
Foreign Currency Transaction Gain (Loss), Realized	(10)	79	(124)
Debt and Equity Securities, Realized Gain (Loss)	1,200	1,100	1,300
Other limited partnership interests
Debt Securities, Available-for-sale [Line Items]
Gain (Loss) on Sale of Investments			46
Tax credit partnerships
Debt Securities, Available-for-sale [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net			92
Lease Agreements
Debt Securities, Available-for-sale [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net			30
Equity securities
Debt Securities, Available-for-sale [Line Items]
Equity Securities, FV-NI, Unrealized Gain (Loss)	77	(127)	122
Cash Flow Hedging [Member]
Debt Securities, Available-for-sale [Line Items]
Net investment gains (losses)	82	207	8
Cash Flow Hedging [Member] \| Currency Swap [Member]
Debt Securities, Available-for-sale [Line Items]
Net investment gains (losses)	(403)	851	$ 240
Foreign Currency Gain (Loss) [Member] \| Reclassification out of Accumulated Other Comprehensive Income \| Cash Flow Hedging [Member] \| Currency Swap [Member]
Debt Securities, Available-for-sale [Line Items]
Net investment gains (losses)	$ 88	$ 129

Amount of realized gain (loss) on investment in debt and equity securities.

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement.

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Amount of realized and unrealized gain (loss) on investment.

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The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

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Amount of gain (loss) on termination of lease before expiration of lease term.

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The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

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