Fair Value Disclosures - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Nov. 30, 2013
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other secured financings	$ 270,394,000		$ 234,711,000
Debt instrument maturity year	Mar. 01, 2016
Transfers of assets from Level 2 to Level 3	91,000,000	100,500,000
Transfers of assets from Level 3 to Level 2	47,300,000	112,700,000
Transfers of liabilities from Level 2 to Level 3	4,800,000	0
Transfers of liabilities from Level 3 to Level 2	2,900,000	700,000
Transfers of net derivative liabilities from Level 3 to level 2	3,400,000
Net gains/losses on Level 3 assets (realized and unrealized)	20,300,000	14,500,000
Net gains/losses on Level 3 liabilities (realized and unrealized)	1,100,000	2,700,000
Unadjusted net asset value of the funds	114,900,000		127,700,000
Unadjusted net liability value of the funds	1,000,000		14,400,000
Loan receivables on nonaccrual status	0		0
Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other secured financings	30,400,000
3.875% Convertible Senior Debentures, due 2029 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Debt instrument interest rate	3.875%
3.875% Convertible Senior Debentures, due 2029 [Member] | Leucadia [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Debt instrument interest rate	3.875%
Debt instrument maturity year	Nov. 01, 2029
Volatility curve used in valuing embedded option	252 days
Embedded Conversion Option [Member] | Leucadia [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Debt instrument maturity year	Nov. 01, 2017
Residential mortgage-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 2 to Level 3	38,100,000	78,400,000
Transfers of assets from Level 3 to Level 2	19,100,000	73,500,000
Commercial mortgage-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 2 to Level 3	9,000,000	1,300,000
Transfers of assets from Level 3 to Level 2	200,000	10,900,000
Corporate debt securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 2 to Level 3	2,300,000	10,800,000
Transfers of assets from Level 3 to Level 2	200,000
Corporate equity securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 2 to Level 3	7,400,000	100,000
Transfers of assets from Level 3 to Level 2	3,600,000	4,700,000
Collateralized debt obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 2 to Level 3	23,500,000	5,300,000
Transfers of assets from Level 3 to Level 2	3,300,000	2,400,000
Loans and other receivables [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 2 to Level 3	8,900,000	4,800,000
Transfers of assets from Level 3 to Level 2	7,900,000	19,900,000
Other asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 2 to Level 3	1,800,000
Transfers of assets from Level 3 to Level 2	12,200,000	200,000
Investments at fair value [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Transfers of assets from Level 3 to Level 2	$ 800,000