Investments - Portfolio composition (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Investments [Abstract]
Fixed income securities, at fair value	$ 23,907	$ 21,725
Mortgage loans, net	3,359	3,988
Equity securities, at fair value	1,536	1,469
Limited partnership interests	3,065	3,250
Short-term investments, at fair value	974	1,191
Policy loans	582	557
Other, net	1,375	1,427
Total investments	$ 34,798	$ 33,607

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

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Sum of the carrying amounts as of the balance sheet date of all investments.

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Amount of investment in equity method investee and investment in and advance to affiliate.

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Amount before allowance of loans made to policy and contract holders using their life insurance contracts' cash value or separate accounts as collateral. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums over and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

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Amount of investments classified as other.

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Amount of short-term investments classified as other.

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