Segment Reporting - Net Revenues, Expenses and Total Assets by Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Feb. 28, 2015	Feb. 28, 2014	Nov. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 591,672	$ 899,028
Expenses	578,788	716,759
Segment assets	43,786,728		44,517,648
Capital Markets [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	562,500	876,900
Expenses	572,300	705,700
Segment assets	43,165,200		44,002,600
Asset Management [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	29,200	22,100
Expenses	6,500	11,100
Segment assets	$ 621,500		$ 515,000