Segment Reporting - Net Revenues, Expenses and Total Assets by Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Aug. 31, 2013 Successor [Member]	Aug. 31, 2013 Successor [Member]	Aug. 31, 2013 Successor [Member] Capital Markets [Member]	Aug. 31, 2013 Successor [Member] Capital Markets [Member]	Aug. 31, 2013 Successor [Member] Asset Management [Member]	Aug. 31, 2013 Successor [Member] Asset Management [Member]	Feb. 28, 2013 Predecessor [Member]	Aug. 31, 2012 Predecessor [Member]	Aug. 31, 2012 Predecessor [Member]	Nov. 30, 2012 Predecessor [Member]	Feb. 28, 2013 Predecessor [Member] Capital Markets [Member]	Aug. 31, 2012 Predecessor [Member] Capital Markets [Member]	Aug. 31, 2012 Predecessor [Member] Capital Markets [Member]	Nov. 30, 2012 Predecessor [Member] Capital Markets [Member]	Feb. 28, 2013 Predecessor [Member] Asset Management [Member]	Aug. 31, 2012 Predecessor [Member] Asset Management [Member]	Aug. 31, 2012 Predecessor [Member] Asset Management [Member]	Nov. 30, 2012 Predecessor [Member] Asset Management [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 517,029	$ 1,159,556	$ 500,600	$ 1,119,400	$ 16,400	$ 40,200	$ 803,387	$ 738,938	$ 2,229,935		$ 792,500	$ 735,800	$ 2,219,300		$ 10,900	$ 3,100	$ 10,600
Expenses	493,647	1,067,553	485,400	1,047,000	8,200	20,600	652,939	608,265	1,817,511		645,400	603,600	1,794,100		7,500	4,700	23,400
Segment Assets	$ 38,830,213	$ 38,830,213	$ 37,978,600	$ 37,978,600	$ 851,600	$ 851,600				$ 36,293,541				$ 35,588,600				$ 704,900