Investments - Net Investment Income (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Investment Income [Line Items]
Investment revenue	$ 8,373	$ 7,709	$ 5,338
Investment expenses	(802)	(609)	(504)
Net investment income	7,571	7,100	4,834
Trading securities
Net Investment Income [Line Items]
Investment revenue	194	260	192
Equity securities
Net Investment Income [Line Items]
Investment revenue	64	19	14
Mortgage loans, net of allowances
Net Investment Income [Line Items]
Investment revenue	1,261	802	702
Investment funds
Net Investment Income [Line Items]
Investment revenue	550	1,908	710
Funds withheld at interest
Net Investment Income [Line Items]
Investment revenue	1,844	781	269
Other
Net Investment Income [Line Items]
Investment revenue	270	271	226
Foreign currency forwards
Net Investment Income [Line Items]
Investment revenue	$ 4,190	$ 3,668	$ 3,225

Amount, before investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

+ References

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