Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Aug. 31, 2015	Nov. 30, 2014
Cash and cash equivalents ($259 and $178 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	$ 3,441,785	$ 4,079,968
Financial instruments owned, at fair value, (including securities pledged of $14,151,752 and $14,794,488 at August 31, 2015 and November 30, 2014, respectively; and $86,704 and $62,990 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	14,151,752	14,794,488
Financial instruments owned, at fair value, (including securities pledged of $14,151,752 and $14,794,488 at August 31, 2015 and November 30, 2014, respectively; and $86,704 and $62,990 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	18,892,372	18,636,612
Fees, interest and other ($347 and $363 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	303,720	262,437
Other secured financings ($806,634 and $597,999 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	806,634	605,824
Accrued expenses and other liabilities ($977 and $589 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	1,062,750	1,273,378
Variable Interest Entities [Member]
Cash and cash equivalents ($259 and $178 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	259	178
Financial instruments owned, at fair value, (including securities pledged of $14,151,752 and $14,794,488 at August 31, 2015 and November 30, 2014, respectively; and $86,704 and $62,990 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	86,704	62,990
Fees, interest and other ($347 and $363 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	347	363
Other secured financings ($806,634 and $597,999 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	806,634	597,999
Accrued expenses and other liabilities ($977 and $589 at August 31, 2015 and November 30, 2014, respectively, related to consolidated VIEs)	$ 977	$ 589