Composition of the Company's Loan Portfolio (Additional Information) (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Fair Value Disclosure	$ 255	$ 257
Loans Held-for-sale, Fair Value Disclosure	1,593	1,494
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Fair Value Disclosure	$ 255	$ 257
Accrual Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage Of Accruing Troubled Debt Restructurings, Current	97.00%	97.00%

Percentage Of Accruing Troubled Debt Restructurings, Current

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- Definition

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+ References

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- Definition

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

+ References

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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Glossary Loan
-URI http://asc.fasb.org/extlink&oid=6517073

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