Fair Value - Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Assets
Mortgage loans	$ 5,470	$ 5,500
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party
Assets
Mortgage loans	5,470	5,500
Policy loans	602	642
Funds withheld at interest	6,538	3,482
Other investments	81	83
Short-term investments	189	135
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party \| Carrying Value
Assets
Investment funds	590	581
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party \| Fair Value
Assets
Mortgage loans	44	48
Investment funds	590	581
Funds withheld at interest	140	36
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party \| Level 3 \| Carrying Value
Assets
Mortgage loans	5,426	5,452
Funds withheld at interest	6,398	3,446
Other investments	81	83
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party \| Level 3 \| Fair Value
Assets
Mortgage loans	5,560	5,567
Funds withheld at interest	6,398	3,446
Other investments	81	83
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party \| Level 2 \| Carrying Value
Assets
Policy loans	602	642
Consolidated Entity Excluding Variable Interest Entities (VIE) and Related Party \| Level 2 \| Fair Value
Assets
Policy loans	602	642
Consolidated Entity Excluding Variable Interest Entities (VIE)
Liabilities
Interest sensitive contract liabilities	61,532	57,289
Funds withheld liability	380	388
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Carrying Value
Assets
Total assets not carried at fair value	14,532	11,501
Liabilities
Total liabilities not carried at fair value	28,002	24,006
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Fair Value
Assets
Total assets not carried at fair value	14,691	11,627
Liabilities
Interest sensitive contract liabilities	6,574	6,346
Funds withheld liability	6	35
Total liabilities not carried at fair value	27,304	23,324
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Level 3 \| Carrying Value
Liabilities
Interest sensitive contract liabilities	27,628	23,653
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Level 3 \| Fair Value
Liabilities
Interest sensitive contract liabilities	26,930	22,971
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Level 2 \| Carrying Value
Liabilities
Funds withheld liability	374	353
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Level 2 \| Fair Value
Liabilities
Funds withheld liability	374	353
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Related Party
Assets
Other investments	237	245
Short-term investments	0	55
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Related Party \| Carrying Value
Assets
Investment funds	1,198	997
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Related Party \| Fair Value
Assets
Investment funds	1,198	997
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Related Party \| Level 3 \| Carrying Value
Assets
Other investments	237	245
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Related Party \| Level 3 \| Fair Value
Assets
Other investments	262	256
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Related Party \| Level 2 \| Carrying Value
Assets
Short-term investments	0	55
Consolidated Entity Excluding Variable Interest Entities (VIE) \| Related Party \| Level 2 \| Fair Value
Assets
Short-term investments	$ 0	$ 55

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Fair value of investments in certain entities that calculate net asset value per share, including, but not limited to, by unit, membership interest, or other ownership interest. Investments include, but are not limited to, investments in certain hedge funds, venture capital funds, private equity funds, real estate partnerships or funds.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

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Amount of the reinsurer's funds held on its behalf by the ceding insurer, including funds held in trust, under reinsurance treaties or contracts with the assuming insurer as security for the payment of the obligations thereunder.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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Amount of investments classified as other.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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