Business Segments - Depreciation and Amortization (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 247	$ 222	$ 731	$ 706
Investment Banking [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	32	32	95	90
Institutional Client Services [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	118	104	346	326
Investing and Lending [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	52	50	165	182
Investment Management [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 45	$ 36	$ 125	$ 108

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Name:	us-gaap_DepreciationAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration