Fair Value (Financial Instruments Carried at Other Than Fair Value) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Policy loans	$ 9,493	$ 9,680
Liabilities
Collateral financing arrangement	845	993
Junior subordinated debt securities	3,153	3,150
Separate account liabilities	199,970	188,445
Carrying Value
Assets
Mortgage loans	83,754	80,341
Policy loans	9,493	9,680
Other invested assets	1,188	1,183
Premiums, reinsurance and other receivables	2,729	3,678
Other assets	300	318
Liabilities
Policyholder account balances	126,458	119,262
Long-term debt	14,492	13,336
Collateral financing arrangement	845	993
Junior subordinated debt securities	3,153	3,150
Other liabilities	2,113	2,045
Separate account liabilities	115,682	110,837
Estimated Fair Value
Assets
Mortgage loans	88,675	83,079
Policy loans	11,598	11,655
Other invested assets	1,188	1,183
Premiums, reinsurance and other receivables	2,978	3,884
Other assets	301	319
Liabilities
Policyholder account balances	134,569	122,998
Long-term debt	18,332	15,830
Collateral financing arrangement	710	810
Junior subordinated debt securities	4,604	4,405
Other liabilities	3,133	2,819
Separate account liabilities	115,682	110,837
Estimated Fair Value \| Level 1
Assets
Mortgage loans	0	0
Policy loans	0	0
Other invested assets	0	0
Premiums, reinsurance and other receivables	0	0
Other assets	0	0
Liabilities
Policyholder account balances	0	0
Long-term debt	0	0
Collateral financing arrangement	0	0
Junior subordinated debt securities	0	0
Other liabilities	0	0
Separate account liabilities	0	0
Estimated Fair Value \| Level 2
Assets
Mortgage loans	0	0
Policy loans	0	326
Other invested assets	814	809
Premiums, reinsurance and other receivables	908	1,178
Other assets	111	131
Liabilities
Policyholder account balances	0	0
Long-term debt	18,332	15,830
Collateral financing arrangement	0	0
Junior subordinated debt securities	4,604	4,405
Other liabilities	527	540
Separate account liabilities	115,682	110,837
Estimated Fair Value \| Level 3
Assets
Mortgage loans	88,675	83,079
Policy loans	11,598	11,329
Other invested assets	374	374
Premiums, reinsurance and other receivables	2,070	2,706
Other assets	190	188
Liabilities
Policyholder account balances	134,569	122,998
Long-term debt	0	0
Collateral financing arrangement	710	810
Junior subordinated debt securities	0	0
Other liabilities	2,606	2,279
Separate account liabilities	$ 0	$ 0

Total amount of mortgage loans not valued on a recurring basis as of the balance sheet date.

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Fair value portion of other investments not otherwise specified in the taxonomy.

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Fair value portion of the liability of policyholders for deposits held under the terms of insurance contracts.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments.

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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 fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Fair value portion of other assets.

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Fair value portion of other liabilities.

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Fair value portion of receivables, including, but not limited to, trade account receivables, note receivables, and loan receivables.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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Amount of liability for variable contract in which all or portion of contract holder's funds is allocated to specific separate account and supported by assets held in separate account.

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