Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Feb. 28, 2013	Feb. 29, 2012
Summary Of Significant Accounting Policies [Line Items]
Soft dollar expenses	$ 8.5	$ 8.2
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life of premises and equipment	3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life of premises and equipment	10 years

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration