Fair Value Disclosures - Summary of Changes in Fair Value of Financial Assets Classified as Level 3 (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended	9 Months Ended
	Aug. 31, 2013	Feb. 28, 2013	Aug. 31, 2012	Aug. 31, 2013	Aug. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total gains/losses (realized and unrealized)	$ 1,000	$ (14,500)	$ (2,000)	$ 12,700	$ 23,600
Corporate equity securities [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	19,577			13,234
Total gains/losses (realized and unrealized)	(788)			1,053
Purchases				213
Sales	(930)			(753)
Settlements				266
Net transfers into/ (out of) Level 3	(1,780)			2,066
Ending Balance	16,079			16,079
Change in unrealized gains/(losses) relating to instruments still held	(786)			1,243
Corporate equity securities [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		16,815	25,789		13,489
Total gains/losses (realized and unrealized)		200	260		(2,580)
Purchases		707	2,991		20,676
Sales		109	(15,418)		(13,437)
Net transfers into/ (out of) Level 3		(4,597)	6,161		1,635
Ending Balance		13,234	19,783		19,783
Change in unrealized gains/(losses) relating to instruments still held		172	(907)		(4,636)
Corporate debt securities [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	18,615			31,820
Total gains/losses (realized and unrealized)	(4,285)			(17,415)
Purchases	68			708
Sales	(571)			(2,556)
Settlements
Net transfers into/ (out of) Level 3	6,806			8,076
Ending Balance	20,633			20,633
Change in unrealized gains/(losses) relating to instruments still held	(4,342)			(6,933)
Corporate debt securities [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		3,631	7,972		48,140
Total gains/losses (realized and unrealized)		7,836	(101)		85
Purchases		11,510	521		7,228
Sales		(1,918)	(1,118)		(39,367)
Settlements					(1,276)
Net transfers into/ (out of) Level 3		10,761	284		(7,252)
Ending Balance		31,820	7,558		7,558
Change in unrealized gains/(losses) relating to instruments still held		7,833	(136)		(656)
Collateralized debt obligations [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	45,124			29,776
Total gains/losses (realized and unrealized)	(1,903)			(2,008)
Purchases	8,222			43,152
Sales	(4,236)			(27,676)
Settlements
Net transfers into/ (out of) Level 3	(1,335)			2,628
Ending Balance	45,872			45,872
Change in unrealized gains/(losses) relating to instruments still held	(2,388)			(3,830)
Collateralized debt obligations [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		31,255	84,006		47,988
Total gains/losses (realized and unrealized)		3,624	6,710		4,278
Purchases		9,406			8,479
Sales		(17,374)	(11,008)		(18,699)
Settlements					(3,892)
Net transfers into/ (out of) Level 3		2,865	1,890		43,444
Ending Balance		29,776	81,598		81,598
Change in unrealized gains/(losses) relating to instruments still held		(1,125)	5,836		3,515
Residential mortgage-backed securities [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	143,766			169,426
Total gains/losses (realized and unrealized)	(1,876)			5,594
Purchases	33,831			79,531
Sales	(50,938)			(105,671)
Settlements	(2,306)			(4,851)
Net transfers into/ (out of) Level 3	9,706			(11,846)
Ending Balance	132,183			132,183
Change in unrealized gains/(losses) relating to instruments still held	(3,898)			586
Residential mortgage-backed securities [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		156,069	123,555		149,965
Total gains/losses (realized and unrealized)		11,906	2,542		(17,833)
Purchases		132,773	27,401		59,477
Sales		(130,143)	(65,422)		(101,039)
Settlements		(6,057)	(5,216)		(8,489)
Net transfers into/ (out of) Level 3		4,878	62,128		62,907
Ending Balance		169,426	144,988		144,988
Change in unrealized gains/(losses) relating to instruments still held		4,511	359		(8,884)
Commercial mortgage-backed securities [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	16,068			17,794
Total gains/losses (realized and unrealized)	2,033			(735)
Purchases	130			1,533
Sales	(310)			(3,054)
Settlements	(3,703)			(5,281)
Net transfers into/ (out of) Level 3	205			4,166
Ending Balance	14,423			14,423
Change in unrealized gains/(losses) relating to instruments still held	(1,106)			(5,007)
Commercial mortgage-backed securities [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		30,202	40,594		52,407
Total gains/losses (realized and unrealized)		(995)	(1,327)		(2,221)
Purchases		2,280	2,092		5,090
Sales		(2,866)	(1,307)		(5,441)
Settlements		(1,188)	(450)		(115)
Net transfers into/ (out of) Level 3		(9,639)	(8,089)		(18,207)
Ending Balance		17,794	31,513		31,513
Change in unrealized gains/(losses) relating to instruments still held		(2,059)	(1,310)		(2,769)
Other asset-backed securities [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	1,444			1,252
Total gains/losses (realized and unrealized)	2,170			2,168
Purchases	7,576			7,618
Sales	(3,279)			(3,127)
Settlements
Net transfers into/ (out of) Level 3	659			659
Ending Balance	8,570			8,570
Change in unrealized gains/(losses) relating to instruments still held	2,142			2,077
Other asset-backed securities [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		1,114	1,273		3,284
Total gains/losses (realized and unrealized)		50			141
Purchases		1,627			19,397
Sales		(1,342)			(20,351)
Settlements		(19)	(291)		(51)
Net transfers into/ (out of) Level 3		(178)	(774)		(2,212)
Ending Balance		1,252	208		208
Change in unrealized gains/(losses) relating to instruments still held		(1)			3
Loans and other receivables [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	117,496			170,986
Total gains/losses (realized and unrealized)	(198)			(5,103)
Purchases	52,246			206,672
Sales	(12,139)			(26,630)
Settlements	(25,395)			(213,662)
Net transfers into/ (out of) Level 3	(1,558)			(1,811)
Ending Balance	130,452			130,452
Change in unrealized gains/(losses) relating to instruments still held	609			(8,063)
Loans and other receivables [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		180,393	108,674		97,291
Total gains/losses (realized and unrealized)		(8,682)	(528)		(2,674)
Purchases		105,650	57,790		158,305
Sales		(29,828)	(30,632)		(60,111)
Settlements		(61,407)	(56,404)		(104,476)
Net transfers into/ (out of) Level 3		(15,140)	29,889		20,454
Ending Balance		170,986	108,789		108,789
Change in unrealized gains/(losses) relating to instruments still held		(12,374)	(237)		(4,109)
Investments, at fair value [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	76,364			70,067
Total gains/losses (realized and unrealized)	1,848			653
Purchases				5,000
Sales	(101)			(102)
Settlements	(710)			(3,204)
Net transfers into/ (out of) Level 3	(3,949)			1,038
Ending Balance	73,452			73,452
Change in unrealized gains/(losses) relating to instruments still held	2,002			668
Investments, at fair value [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		83,897	91,836		78,326
Total gains/losses (realized and unrealized)		961	(202)		15,076
Purchases		952	1,120		1,909
Sales		(4,923)			(6)
Settlements		(9,721)	(775)		(3,326)
Net transfers into/ (out of) Level 3		(1,099)
Ending Balance		70,067	91,979		91,979
Change in unrealized gains/(losses) relating to instruments still held		1,171	(466)		14,412
Investments in managed funds [Member] | Successor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	55,141			59,976
Total gains/losses (realized and unrealized)	4,034			3,108
Purchases	6,598			9,130
Sales
Settlements	(9,876)			(16,439)
Net transfers into/ (out of) Level 3				122
Ending Balance	55,897			55,897
Change in unrealized gains/(losses) relating to instruments still held	4,034			3,108
Investments in managed funds [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		57,763	68,314		70,740
Total gains/losses (realized and unrealized)		(363)	(5,389)		(17,765)
Purchases		11,068	2,173		12,683
Settlements		(8,492)	(4,987)		(5,537)
Net transfers into/ (out of) Level 3			10
Ending Balance		59,976	60,121		60,121
Change in unrealized gains/(losses) relating to instruments still held		(363)	(5,382)		(17,765)
Municipal securities [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			465		6,904
Total gains/losses (realized and unrealized)			5		(74)
Sales			(387)		(1,366)
Net transfers into/ (out of) Level 3					(5,381)
Ending Balance			83		83
Change in unrealized gains/(losses) relating to instruments still held			5		5
Sovereign obligations [Member] | Predecessor [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance					140
Net transfers into/ (out of) Level 3					$ (140)