Investments and Derivative Instruments Level 4 Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Assets Sold under Agreements to Repurchase [Line Items]
Secured Debt, Repurchase Agreements	$ 0us-gaap_SecuredDebtRepurchaseAgreements
Securities Reserve Deposit Required and Made	2,500,000,000	1,900,000,000
US Treasury Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Available-for-sale Securities Pledged as Collateral	34,000,000	34,000,000
JAPAN \| Foreign Government Debt [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Available-for-sale Securities Pledged as Collateral	272,000,000
Loans Pledged as Collateral	$ 238,000,000

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The fair value of available-for-sale securities that serve as collateral for borrowings.

+ References

+ Details

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- Definition

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5086-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6467456&loc=d3e113888-111728

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- Definition

Carrying value, as of the balance sheet date, of securities sold under agreements to repurchase where the transferor maintains effective control over the assets, accounting for them as secured debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(m)(1)(i))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 10

-Section 55

-Paragraph 51

-URI http://asc.fasb.org/extlink&oid=45353962&loc=d3e101761-111710

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- Definition

Securities deposited in a special reserve account for the exclusive benefit of customers pursuant to SEC Regulations.

+ References

No definition available.

+ Details

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