Derivative Financial Instruments - Remaining Contract Maturity of Fair Value of OTC Derivative Assets and Liabilities (Detail) $ in Thousands	Nov. 30, 2015 USD ($)
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	$ 179,591
OTC derivative assets having maturity period of 1 to 5 years	202,753
OTC derivative assets having maturity period of greater than 5 years	63,816
OTC derivative assets cross-maturity netting	(57,965)
Total OTC derivative assets, net of cross-maturity netting	388,195
Cross product counterparty netting	(13,063)
Total OTC derivative assets included in Financial instruments owned	375,132
OTC derivative liabilities having maturity period of 0 to 12 months	175,338
OTC derivative liabilities having maturity period of 1 to 5 years	135,312
OTC derivative liabilities having maturity period of greater than 5 years	127,502
OTC derivative liabilities cross-maturity netting	(57,965)
Total OTC derivative liabilities, net of cross-maturity netting	380,187
Cross product counterparty netting	(13,063)
Total OTC derivative liabilities included in Financial instruments sold, not yet purchased	367,124
Commodity swaps, options and forwards [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	4,628
OTC derivative assets having maturity period of 1 to 5 years	14,713
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	0
Total OTC derivative assets, net of cross-maturity netting	19,341
OTC derivative liabilities having maturity period of 0 to 12 months	4,628
OTC derivative liabilities having maturity period of 1 to 5 years	0
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	4,628
Equity swaps and options [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	26,278
OTC derivative assets having maturity period of 1 to 5 years	7,112
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(3,782)
Total OTC derivative assets, net of cross-maturity netting	29,608
OTC derivative liabilities having maturity period of 0 to 12 months	4,880
OTC derivative liabilities having maturity period of 1 to 5 years	28,516
OTC derivative liabilities having maturity period of greater than 5 years	3,046
OTC derivative liabilities cross-maturity netting	(3,782)
Total OTC derivative liabilities, net of cross-maturity netting	32,660
Credit default swaps [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	0
OTC derivative assets having maturity period of 1 to 5 years	6,022
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(2,839)
Total OTC derivative assets, net of cross-maturity netting	3,183
OTC derivative liabilities having maturity period of 0 to 12 months	0
OTC derivative liabilities having maturity period of 1 to 5 years	2,628
OTC derivative liabilities having maturity period of greater than 5 years	31,982
OTC derivative liabilities cross-maturity netting	(2,839)
Total OTC derivative liabilities, net of cross-maturity netting	31,771
Total return swaps [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	8,648
OTC derivative assets having maturity period of 1 to 5 years	252
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(1)
Total OTC derivative assets, net of cross-maturity netting	8,899
OTC derivative liabilities having maturity period of 0 to 12 months	22,644
OTC derivative liabilities having maturity period of 1 to 5 years	774
OTC derivative liabilities having maturity period of greater than 5 years	2,540
OTC derivative liabilities cross-maturity netting	(1)
Total OTC derivative liabilities, net of cross-maturity netting	25,957
Foreign currency forwards, swaps and options [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	82,382
OTC derivative assets having maturity period of 1 to 5 years	15,780
OTC derivative assets having maturity period of greater than 5 years	0
OTC derivative assets cross-maturity netting	(7,462)
Total OTC derivative assets, net of cross-maturity netting	90,700
OTC derivative liabilities having maturity period of 0 to 12 months	98,726
OTC derivative liabilities having maturity period of 1 to 5 years	12,255
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	(7,462)
Total OTC derivative liabilities, net of cross-maturity netting	103,519
Fixed income forwards [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative liabilities having maturity period of 0 to 12 months	2,522
OTC derivative liabilities having maturity period of 1 to 5 years	0
OTC derivative liabilities having maturity period of greater than 5 years	0
OTC derivative liabilities cross-maturity netting	0
Total OTC derivative liabilities, net of cross-maturity netting	2,522
Interest rate swaps, options and forwards [Member]
Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items]
OTC derivative assets having maturity period of 0 to 12 months	57,655
OTC derivative assets having maturity period of 1 to 5 years	158,874
OTC derivative assets having maturity period of greater than 5 years	63,816
OTC derivative assets cross-maturity netting	(43,881)
Total OTC derivative assets, net of cross-maturity netting	236,464
OTC derivative liabilities having maturity period of 0 to 12 months	41,938
OTC derivative liabilities having maturity period of 1 to 5 years	91,139
OTC derivative liabilities having maturity period of greater than 5 years	89,934
OTC derivative liabilities cross-maturity netting	(43,881)
Total OTC derivative liabilities, net of cross-maturity netting	$ 179,130