Segment Reporting - Net Revenues, Expenses and Total Assets by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2015	Aug. 31, 2014	Nov. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 578,928	$ 843,309	$ 1,962,154	$ 2,465,329
Expenses	571,835	707,674	1,857,465	2,048,288
Segment assets	42,784,678		42,784,678		$ 44,517,648
Capital Markets [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	565,200	828,500	1,916,700	2,423,200
Expenses	564,500	697,800	1,829,300	2,020,600
Segment assets	41,943,500		41,943,500		44,002,600
Asset Management [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	13,800	14,800	45,500	42,100
Expenses	7,300	$ 9,900	28,200	$ 27,700
Segment assets	$ 841,200		$ 841,200		$ 515,000