Hoare Govett Acquisition - Additional Information (Detail)	3 Months Ended		3 Months Ended
	Feb. 29, 2012 USD ($)	Feb. 01, 2012 GBP (£)	Feb. 29, 2012 Hoare Govett [Member] USD ($)	Feb. 01, 2012 Hoare Govett [Member] USD ($)	Feb. 01, 2012 Hoare Govett [Member] GBP (£)
Business Acquisition [Line Items]
Business acquisition employee retention payments agreed by acquiree maximum		£ 1,900,000			£ 1,900,000
Cash paid for acquisition					1
Fair values of net assets acquired, including identifiable intangible assets				300,000
Purchase price of net assets acquired				3,100,000
Bargain purchase gain	$ 3,368,000		$ 3,400,000