Investments and Derivative Instruments Level 4 Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Secured Debt, Repurchase Agreements	$ 0us-gaap_SecuredDebtRepurchaseAgreements
Interest-bearing Deposit Liabilities, Domestic	2,700,000,000	2,500,000,000
Secured Debt, Dollar Rolls	0us-gaap_SecuredDebtDollarRolls
US Treasury Securities [Member]
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Available-for-sale Securities Pledged as Collateral	34,000,000	34,000,000
Fixed Maturities [Member]
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Available-for-sale Securities Pledged as Collateral	323,000,000
Other Liabilities [Member]
Repurchase Agreements, Dollar Roll Transactions and Other Collateral Transactions [Line Items]
Assets Sold under Agreements to Repurchase, Repurchase Liability	$ 323,000,000

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Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph m

-Subparagraph 1

-Article 4

Reference 2: 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)(A)(ii))

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

+ Details

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- Definition

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

+ 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

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- Definition

Total amount of interest-bearing domestic deposit liabilities, which may include brokered, retail, demand, checking, notice of withdrawal, money market and other interest-bearing deposits.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.12)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 9

+ Details

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- Definition

Carrying value, as of the balance sheet date, of an agreement to sell a mortgage-backed security with an agreement to purchase a similar mortgage-backed security at a future date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 10

-Section 55

-Paragraph 53

-URI http://asc.fasb.org/extlink&oid=45353962&loc=d3e101795-111710

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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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