Regulatory Requirements (Narrative) (Details)	Jul. 31, 2011
Regulatory Requirements
Leverage ratio	35.3

Total Aggregate Indebtedness divided by Net Capital.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Rule 15c3
-Number 240
-Article 15c3
-Section 1
-Subsection a
-Paragraph 1
-Subparagraph i

Name:	us-gaap_RatioOfIndebtednessToNetCapital
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant