Goodwill and Other Intangible Assets - Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended		9 Months Ended	6 Months Ended		12 Months Ended
	May 31, 2012	Aug. 31, 2013 Successor [Member]	Aug. 31, 2013 Successor [Member] Exchange and clearing organization membership interests and registrations [Member]	Aug. 31, 2013 Successor [Member] Exchange and clearing organization membership interests and registrations [Member]	Aug. 31, 2013 Successor [Member] Customer relationships [Member]	Aug. 31, 2013 Successor [Member] Trade names (intangible assets) [Member]	Nov. 30, 2012 Predecessor [Member]	Nov. 30, 2012 Predecessor [Member] Exchange and clearing organization membership interests and registrations [Member]	Nov. 30, 2012 Predecessor [Member] Customer relationships [Member]	Nov. 30, 2012 Predecessor [Member] Trade names (intangible assets) [Member]	Nov. 30, 2012 Predecessor [Member] Other intangible assets [Member]
Gross Costs - finite lived intangible assets					$ 136,311	$ 131,609			$ 10,542	$ 1,680	$ 100
Total gross costs - intangible assets		283,412					23,541
Gross costs - indefinite lived intangible assets			15,492	15,492				11,219
Impairment losses	(2,900)	(378)	(378)	(378)			(2,873)	(2,873)
Net carrying amount - indefinte lived intangible assets			15,114	15,114				8,346
Accumulated amortization - finite lived intangible assets		(13,587)			(11,711)	(1,876)	(5,409)		(4,107)	(1,287)	(15)
Net carrying amount - finite lived intangible assets					124,600	129,733			6,435	393	85
Total net carrying amount - intangible assets		$ 269,447					$ 15,259
Weighted average remaining lives (years)					14 years 7 months 6 days	34 years 6 months			7 years 10 months 24 days	3 years 6 months	12 years 9 months 18 days