Consolidated Reinsurance (Consolidated Reinsurance) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums, Life Insurance in Force	$ 4,572,115us-gaap_LifeInsuranceInForceGross	$ 4,517,797us-gaap_LifeInsuranceInForceGross	$ 4,432,178us-gaap_LifeInsuranceInForceGross
Ceded Premiums, Life Insurance in Force	719,154us-gaap_LifeInsuranceInForceCeded	763,754us-gaap_LifeInsuranceInForceCeded	761,993us-gaap_LifeInsuranceInForceCeded
Assumed Premiums, Life Insurance in Force	649,032us-gaap_LifeInsuranceInForceAssumed	607,591us-gaap_LifeInsuranceInForceAssumed	594,062us-gaap_LifeInsuranceInForceAssumed
Premiums, Net, Life Insurance in Force	4,501,993us-gaap_LifeInsuranceInForceNet	4,361,634us-gaap_LifeInsuranceInForceNet	4,264,247us-gaap_LifeInsuranceInForceNet
Life Insurance in Force Premiums, Percentage Assumed to Net	14.40%	13.90%	13.90%
Consolidated Reinsurance
Gross Amount	40,049us-gaap_DirectPremiumsEarned	38,476us-gaap_DirectPremiumsEarned	38,719us-gaap_DirectPremiumsEarned
Ceded	2,454us-gaap_CededPremiumsEarned	2,274us-gaap_CededPremiumsEarned	2,232us-gaap_CededPremiumsEarned
Assumed	1,472us-gaap_AssumedPremiumsEarned	1,472us-gaap_AssumedPremiumsEarned	1,488us-gaap_AssumedPremiumsEarned
Net premiums	39,067us-gaap_PremiumsEarnedNet	37,674us-gaap_PremiumsEarnedNet	37,975us-gaap_PremiumsEarnedNet
% Amount Assumed to Net	3.80%us-gaap_PremiumsPercentageAssumedToNet	3.90%us-gaap_PremiumsPercentageAssumedToNet	3.90%us-gaap_PremiumsPercentageAssumedToNet
Life insurance (1)
Consolidated Reinsurance
Gross Amount	23,575	22,206	22,006
Ceded	2,034	1,862	1,550
Assumed	1,224	1,269	1,268
Net premiums	22,765	21,613	21,724
% Amount Assumed to Net	5.40%	5.90%	5.80%
Accident & health insurance
Consolidated Reinsurance
Gross Amount	13,015	12,957	13,567
Ceded	340	333	605
Assumed	239	196	211
Net premiums	12,914	12,820	13,173
% Amount Assumed to Net	1.90%	1.50%	1.60%
Property and casualty insurance
Consolidated Reinsurance
Gross Amount	3,459	3,313	3,146
Ceded	80	79	77
Assumed	9	7	9
Net premiums	$ 3,388	$ 3,241	$ 3,078
% Amount Assumed to Net	0.30%	0.20%	0.30%

Amount of earned premiums assumed from other entities.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 50

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-Subparagraph (b),(c)(2)

-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

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Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.1)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 1

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 605

-Section 50

-Paragraph 1

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Amount of life insurance issued and outstanding assumed from other entities. Includes, but not limited to, dividends and adjustments to face value.

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Amount of life insurance issued and outstanding ceded to other entities. Includes, but not limited to, dividends and adjustments to face value.

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Amount before contracts ceded to other entities and contracts assumed by the entity of life insurance issued and outstanding. Includes, but not limited to, dividends and adjustments to face value.

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Amount after contracts ceded to other entities and contracts assumed by the entity of life insurance issued and outstanding. Includes, but not limited to, dividends and adjustments to face value.

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Percentage of assumed life insurance issued and outstanding contracts to life insurance issued and outstanding after contracts ceded to other entities and contracts assumed by the entity. Includes, but not limited to, dividends and adjustments to face value.

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Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.1)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 1

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section S99

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-Subparagraph (SX 210.9-04.13(c))

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Percentage of assumed premiums earned by the entity to net premiums earned.

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