Fair Value (Financial Instruments Carried at Other Than Fair Value) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets
Policy loans	$ 836	$ 875
Liabilities
Separate account liabilities	83,049	99,668
Carrying Value
Assets
Mortgage loans	15,457	15,664
Policy loans	836	875
Other invested assets	154	51
Premiums, reinsurance and other receivables	2,177	2,053
Liabilities
Policyholder account balances	15,637	15,474
Short-term Debt, Fair Value	100
Long-term debt	844	844
Other liabilities	1,261	943
Separate account liabilities	949	1,186
Estimated Fair Value
Assets
Mortgage loans	15,775	16,291
Policy loans	1,030	983
Other invested assets	154	51
Premiums, reinsurance and other receivables	2,530	2,468
Liabilities
Policyholder account balances	14,996	15,576
Short-term Debt, Fair Value	100
Long-term debt	642	942
Other liabilities	1,253	946
Separate account liabilities	949	1,186
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
Liabilities
Policyholder account balances	0	0
Short-term Debt, Fair Value	0
Long-term debt	0	0
Other liabilities	0	0
Separate account liabilities	0	0
Estimated Fair Value \| Level 2
Assets
Mortgage loans	0	0
Policy loans	435	479
Other invested assets	39	39
Premiums, reinsurance and other receivables	37	41
Liabilities
Policyholder account balances	0	0
Short-term Debt, Fair Value	0
Long-term debt	38	39
Other liabilities	484	169
Separate account liabilities	949	1,186
Estimated Fair Value \| Level 3
Assets
Mortgage loans	15,775	16,291
Policy loans	595	504
Other invested assets	115	12
Premiums, reinsurance and other receivables	2,493	2,427
Liabilities
Policyholder account balances	14,996	15,576
Short-term Debt, Fair Value	100
Long-term debt	604	903
Other liabilities	769	777
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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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 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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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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