Fair Value (Financial Instruments Carried at Other Than Fair Value) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Assets
Policy loans	$ 1,093	$ 1,266
Liabilities
Separate account liabilities	100,588	101,735
Estimated Fair Value
Assets
Mortgage loans	8,893	7,386
Policy loans	1,177	1,347
Real estate joint ventures	44	65
Other limited partnership interests	42	57
Premiums, reinsurance and other receivables	3,675	7,243
Liabilities
Policyholder account balances	15,975	20,339
Long-term debt	1,060	1,070
Other liabilities	194	217
Separate account liabilities	1,110	1,275
Estimated Fair Value \| Level 1
Assets
Mortgage loans	0	0
Policy loans	0	0
Real estate joint ventures	0	0
Other limited partnership interests	0	0
Premiums, reinsurance and other receivables	0	0
Liabilities
Policyholder account balances	0	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	746	917
Real estate joint ventures	0	0
Other limited partnership interests	0	0
Premiums, reinsurance and other receivables	832	80
Liabilities
Policyholder account balances	0	0
Long-term debt	1,060	1,070
Other liabilities	27	43
Separate account liabilities	1,110	1,275
Estimated Fair Value \| Level 3
Assets
Mortgage loans	8,893	7,386
Policy loans	431	430
Real estate joint ventures	44	65
Other limited partnership interests	42	57
Premiums, reinsurance and other receivables	2,843	7,163
Liabilities
Policyholder account balances	15,975	20,339
Long-term debt	0	0
Other liabilities	167	174
Separate account liabilities	0	0
Carrying Value
Assets
Mortgage loans	8,748	7,090
Policy loans	1,093	1,266
Real estate joint ventures	12	23
Other limited partnership interests	44	52
Premiums, reinsurance and other receivables	2,831	6,074
Liabilities
Policyholder account balances	14,829	18,968
Long-term debt	781	788
Other liabilities	194	217
Separate account liabilities	$ 1,110	$ 1,275

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

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The fair value portion of investments in other limited partnership interests.

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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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The book value of investments in real estate joint ventures including direct and indirect investments.

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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 contracts that meet specified criteria that are backed by assets held in separate accounts and carried at the fair value of those assets.

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