Business Segments Additional Information (Details) $ in Millions	3 Months Ended
Mar. 31, 2017 segment	Mar. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment	5
Operating Segments [Member] \| RBWM [Member]
Segment Reporting Information [Line Items]
Increase (decrease) in segment profit before tax during the three months ended March 31:		$ 3
Increase (decrease) in segment total assets at March 31:		(672)
Operating Segments [Member] \| GBM [Member]
Segment Reporting Information [Line Items]
Increase (decrease) in segment profit before tax during the three months ended March 31:		(8)
Increase (decrease) in segment total assets at March 31:		(93,516)
Increase (decrease) in segment total deposits at March 31:		(8,920)
Operating Segments [Member] \| CMB [Member]
Segment Reporting Information [Line Items]
Increase (decrease) in segment profit before tax during the three months ended March 31:		4
Operating Segments [Member] \| CC (as compared with previously reported Other) [Member]
Segment Reporting Information [Line Items]
Increase (decrease) in segment profit before tax during the three months ended March 31:		1
Increase (decrease) in segment total assets at March 31:		94,188
Increase (decrease) in segment total deposits at March 31:		8,920
Group Reporting Basis, Other Operating Income [Member]
Segment Reporting Information [Line Items]
Gain from change in fair value of debt attributable to credit spread		$ 149

Group Reporting Basis Increase (Decrease) to Profit (Loss) Before Income Tax Expense

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- Definition

Group Reporting Basis, Increase (Decrease) to Segment Assets

+ References

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- Definition

Increase (Decrease) in Banking Deposits

+ References

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- Definition

This item represents the estimated amount of gains and losses from fair value changes included in earnings that are attributable to changes in the instrument-specific credit risk of liabilities with fair values that have been significantly affected during the reporting period by changes in the instrument-specific credit risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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