Derivative Financial Instruments (Details 1) (USD $) In Thousands	3 Months Ended		8 Months Ended	9 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2010	Aug. 31, 2011
Unrealized and realized gains and (losses) on derivative contracts
Unrealized and realized gains and (losses)	$ (156,041)	$ (103,449)	$ 233,690	$ 316,989
Interest rate contracts [Member]
Unrealized and realized gains and (losses) on derivative contracts
Unrealized and realized gains and (losses)	(103,572)	(90,599)	(127,358)	(190,800)
Foreign exchange contracts [Member]
Unrealized and realized gains and (losses) on derivative contracts
Unrealized and realized gains and (losses)	2,200	(1,185)	(369)	(5,981)
Equity contracts [Member]
Unrealized and realized gains and (losses) on derivative contracts
Unrealized and realized gains and (losses)	(74,564)	(14,345)	(61,613)	(178,433)
Commodity contracts [Member]
Unrealized and realized gains and (losses) on derivative contracts
Unrealized and realized gains and (losses)	8,512	2,231	5,963	41,102
Credit contracts [Member]
Unrealized and realized gains and (losses) on derivative contracts
Unrealized and realized gains and (losses)	$ 11,383	$ 449	$ (50,313)	$ 17,123