Long-Term Debt (Schedule of Long-term Debt Instruments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Derivative, Amount of Hedged Item	$ 452,000,000us-gaap_DerivativeAmountOfHedgedItem	$ 445,000,000us-gaap_DerivativeAmountOfHedgedItem
Secured Debt	47,867,000,000us-gaap_SecuredDebt	47,594,000,000us-gaap_SecuredDebt
Long-term debt	66,558,000,000us-gaap_LongTermDebt	69,465,000,000us-gaap_LongTermDebt
Fixed Income Interest Rate [Member]
Debt Instrument [Line Items]
Unsecured Debt	18,961,000,000	21,367,000,000
Trust preferred securities	2,626,000,000	2,624,000,000
Secured Debt	19,827,000,000	20,492,000,000
Variable Income Interest Rate [Member]
Debt Instrument [Line Items]
Unsecured Debt	376,000,000	2,755,000,000
Secured Debt	24,316,000,000	21,782,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Derivative, Amount of Hedged Item	452,000,000	445,000,000
Long-term debt	22,415,000,000	27,191,000,000
Long-term Debt, Weighted Average Interest Rate	5.90%	6.28%
Secured Debt [Member]
Debt Instrument [Line Items]
Derivative, Amount of Hedged Item	0	0
Long-term debt	44,143,000,000	42,274,000,000
Long-term Debt, Weighted Average Interest Rate	0.94%	0.98%
Variable Interest Entity Debt	24,300,000,000	24,100,000,000
Subordinated Debt [Member]
Debt Instrument [Line Items]
Unsecured Debt	297,000,000	271,000,000
Revolving secured funding facilities [Member]
Debt Instrument [Line Items]
Secured Debt	$ 17,000,000,000	$ 15,100,000,000
Minimum [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-Term Debt Interest Rate	0.33%	0.32%
Minimum [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Long-Term Debt Interest Rate	0.21%	0.40%
Maximum [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-Term Debt Interest Rate	8.30%	10.29%
Maximum [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Long-Term Debt Interest Rate	4.59%	4.59%

Long-Term Debt Interest Rate

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- Definition

Trust preferred securities

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No definition available.

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- Definition

Variable Interest Entity Debt

+ References

No definition available.

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- Definition

Amount of the hedged item as of the balance sheet date related to the derivative. For example, the hedged balance on a debt instrument.

+ References

No definition available.

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

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- Definition

Weighted average interest rate of long-term debt outstanding.

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No definition available.

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- Definition

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

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-Publisher SEC

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph (SX 210.9-03.16)

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-Publisher SEC

-Name Regulation S-X (SX)

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