Troubled Debt Restructurings (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012 Contract
Financing Receivable, Modifications [Line Items]
Number of contracts	53
Outstanding recorded investment Pre-modification	$ 19
Outstanding recorded investment Post- modification	20
Domestic \| Other Residential Mortgages
Financing Receivable, Modifications [Line Items]
Number of contracts	52
Outstanding recorded investment Pre-modification	15
Outstanding recorded investment Post- modification	16
Domestic \| Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of contracts	1
Outstanding recorded investment Pre-modification	4
Outstanding recorded investment Post- modification	$ 4

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 33

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953676-111524

+ Details

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- Definition

Amount of investment in financing receivables (after modification) modified by troubled debt restructurings.

+ References

+ Details

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- Definition

Amount of investment in financing receivables (before modification) modified by troubled debt restructurings.

+ References

+ Details

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