Deposits and Borrowings - Long-Term Debt (Detail) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term Debt and Capital Lease Obligations	$ 41,757	$ 31,377
Debt and Capital Lease Obligations	$ 42,778	48,457
Securitized debt obligations
Debt Instrument [Line Items]
Interest rate, minimum	0.25%
Interest rate, maximum	5.75%
Weighted average interest rate	1.37%
Long-term debt	$ 15,656	11,624
Total senior and subordinated notes
Debt Instrument [Line Items]
Long-term debt	$ 21,773	18,684
Senior notes \| Total unsecured senior debt
Debt Instrument [Line Items]
Weighted average interest rate	2.51%
Long-term debt	$ 19,119	16,054
Senior notes \| Fixed unsecured senior debt
Debt Instrument [Line Items]
Interest rate, minimum	1.00%
Interest rate, maximum	6.75%
Weighted average interest rate	2.65%
Long-term debt	$ 17,539	15,174
Senior notes \| Floating unsecured senior debt
Debt Instrument [Line Items]
Interest rate, minimum	0.77%
Interest rate, maximum	1.47%
Weighted average interest rate	1.00%
Long-term debt	$ 1,580	880
Subordinated notes \| Fixed unsecured subordinated debt
Debt Instrument [Line Items]
Interest rate, minimum	3.38%
Interest rate, maximum	8.80%
Weighted average interest rate	4.97%
Long-term debt	$ 2,654	2,630
FHLB advances
Debt Instrument [Line Items]
Interest rate, minimum	0.25%
Interest rate, maximum	6.41%
Weighted average interest rate	0.32%
Long-term debt	$ 4,304	1,069
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Interest rate, minimum	3.09%
Interest rate, maximum	12.86%
Weighted average interest rate	4.24%
Long-term debt	$ 24	0
FHLB Advance and Capital Lease Obligation [Member]
Debt Instrument [Line Items]
Long-term debt	$ 4,328	$ 1,069

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Maximum contractual interest rate for funds borrowed, under the debt agreement.

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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 FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

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Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

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Weighted average interest rate of long-term debt outstanding.

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