Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Feb. 29, 2012	Feb. 28, 2011
Net revenues, expenses, and total assets by segment
Net revenues	$ 779,966	$ 758,382
Expenses	609,253	579,013
Capital Markets [Member]
Net revenues, expenses, and total assets by segment
Net revenues	774,400	734,500
Expenses	603,200	569,600
Asset Management [Member]
Net revenues, expenses, and total assets by segment
Net revenues	5,600	23,900
Expenses	$ 6,100	$ 9,400