Loans and asset quality- Troubled Debt Restructurings (Detail) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($) Contract	Dec. 31, 2014 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Number of contracts (contracts) \| Contract	72	110
Outstanding recorded investment Pre-modification	$ 13	$ 22
Outstanding recorded investment Post- modification	$ 16	$ 24
Total Domestic \| Other residential mortgages
Financing Receivable, Modifications [Line Items]
Number of contracts (contracts) \| Contract	68	108
Outstanding recorded investment Pre-modification	$ 13	$ 17
Outstanding recorded investment Post- modification	$ 16	$ 20
Total Domestic \| Wealth management loans and mortgages
Financing Receivable, Modifications [Line Items]
Number of contracts (contracts) \| Contract	4	1
Outstanding recorded investment Pre-modification	$ 0	$ 0
Outstanding recorded investment Post- modification	$ 0	$ 0
Foreign
Financing Receivable, Modifications [Line Items]
Number of contracts (contracts) \| Contract	0	1
Outstanding recorded investment Pre-modification	$ 0	$ 5
Outstanding recorded investment Post- modification	$ 0	$ 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=49124121&loc=SL6953676-111524

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Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

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Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

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