Lines of Businesses- Contribution of Segments to Overall Profitability (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2012
Segment Reporting Information [Line Items]
Fee and other revenue	$ 2,878	[1]	$ 2,881	[2]	$ 2,870	[3]
Net interest revenue	719		725		765
Total revenue	3,597		3,606		3,635
Provision for credit losses	(24)		(61)		5
Noninterest expense	2,828		2,825		2,756
Income (loss) before taxes	793	[1]	842	[2]	874	[3]
Pre-tax operating margin (percent)	22.00%	[4]	23.00%	[4]	24.00%	[4]
Average assets	333,664		335,995		301,344
Investment Management
Segment Reporting Information [Line Items]
Fee and other revenue	894	[1]	933	[2]	852	[3]
Net interest revenue	62		55		55
Total revenue	956		988		907
Provision for credit losses	0		0		0
Noninterest expense	745		762		670
Income (loss) before taxes	211	[1]	226	[2]	237	[3]
Pre-tax operating margin (percent)	22.00%	[4]	23.00%	[4]	26.00%	[4]
Average assets	38,743		37,750		36,473
Investment Services
Segment Reporting Information [Line Items]
Fee and other revenue	1,860		1,765		1,843
Net interest revenue	653		591		648
Total revenue	2,513		2,356		2,491
Provision for credit losses	0		0		16
Noninterest expense	1,828		1,830		1,846
Income (loss) before taxes	685		526		629
Pre-tax operating margin (percent)	27.00%	[4]	22.00%	[4]	25.00%	[4]
Average assets	238,374		241,653		212,737
Other
Segment Reporting Information [Line Items]
Fee and other revenue	124		183		175
Net interest revenue	4		79		62
Total revenue	128		262		237
Provision for credit losses	(24)		(61)		(11)
Noninterest expense	255		233		240
Income (loss) before taxes	(103)		90		8
Average assets	$ 56,547		$ 56,592		$ 52,134

[1] Total fee and other revenue includes income from consolidated investment management funds of $50 million, net of noncontrolling interests of $16 million, for a net impact of $34 million. Income before taxes includes noncontrolling interests of $16 million.

[2] Total fee and other revenue includes income from consolidated investment management funds of $42 million, net of noncontrolling interests of $11 million, for a net impact of $31 million. Income before taxes includes noncontrolling interests of $11 million.

[3] Total fee and other revenue includes income from consolidated investment management funds of $43 million, net of noncontrolling interests of $11 million, for a net impact of $32 million. Income before taxes includes noncontrolling interests of $11 million.

[4] Income before taxes divided by total revenue.