Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	8 Months Ended	9 Months Ended
Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2010	Aug. 31, 2011
Summary of Significant Accounting Policies (Textuals) [Abstract]
Soft Dollar expenses	$ 14.1	$ 8.7	$ 25.8	$ 36.4
Minimum useful life of premise and equipment, years				3
Maximum useful life of premise and equipment, years				10

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