Finite Lived Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite Lived Intangible Assets Net [Line Items]
Cost	$ 3,935	$ 3,723
Accumulated amortization	2,367	2,038
Net carrying value	1,568us-gaap_FiniteLivedIntangibleAssetsNet	1,685us-gaap_FiniteLivedIntangibleAssetsNet
Other Assets [Member]
Finite Lived Intangible Assets Net [Line Items]
Cost	1,579	1,613
Accumulated amortization	870	711
Net carrying value	709	902
Customer Relationships [Member] \| Other Assets [Member]
Finite Lived Intangible Assets Net [Line Items]
Cost	1,266	1,289
Accumulated amortization	779	635
Net carrying value	487	654
Other Intangibles [Member] \| Other Assets [Member]
Finite Lived Intangible Assets Net [Line Items]
Cost	313	324
Accumulated amortization	91	76
Net carrying value	222	248
Value Of Business Acquired [Member] \| Deferred Policy Acquisition Costs [Member]
Finite Lived Intangible Assets Net [Line Items]
Cost	165	168
Accumulated amortization	30	20
Net carrying value	135	148
Internal-use software [Member] \| Property And Equipment [Member]
Finite Lived Intangible Assets Net [Line Items]
Cost	2,191	1,942
Accumulated amortization	1,467	1,307
Net carrying value	$ 724	$ 635

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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