Fair Value Disclosures - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Feb. 28, 2025	Feb. 29, 2024	Nov. 30, 2024
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	$ 52,500	$ 11,200
Transfers of assets from Level 3 to Level 2	96,600	59,400
Transfers of liabilities from Level 2 to Level 3	22,100	31,600
Transfers of liabilities from Level 3 to Level 2	53,700	24,600
Net losses on Level 3 assets (realized and unrealized)	(5,400)	(17,900)
Net gains on Level 3 liabilities (realized and unrealized)	72,900	(11,900)
Value of asset excluded from significant unobservable inputs	21,900		$ 23,900
Value of liability excluded from significant unobservable inputs	4,000		2,700
Aggregate fair value of loans and other receivables on nonaccrual status and/or 90 days or greater past due	113,400		126,900
Loan and other receivables greater than 90 days past due	111,000		120,000
Equity securities without readily determinable fair value	21,900		$ 21,900
Impairment	0	0
Monashee
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity method investments		21,900
Loans and other receivables
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	24,800	6,500
Transfers of assets from Level 3 to Level 2	38,700	20,200
Net losses on Level 3 assets (realized and unrealized)	(949)	(15,592)
Corporate equity securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	20,500	1,300
Transfers of assets from Level 3 to Level 2	51,000	9,100
Net losses on Level 3 assets (realized and unrealized)	2,864	(197)
Net gains on Level 3 liabilities (realized and unrealized)	72	7
Collateralized debt obligations and collateralized loan obligations
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	5,700
Net losses on Level 3 assets (realized and unrealized)	(4,646)	11,121
Corporate debt securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3		1,700
Transfers of assets from Level 3 to Level 2	4,200	13,000
Net losses on Level 3 assets (realized and unrealized)	(1,002)	846
Net gains on Level 3 liabilities (realized and unrealized)	40	0
Other ABS
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3		1,700
Transfers of assets from Level 3 to Level 2	2,300	2,200
Net losses on Level 3 assets (realized and unrealized)	(1,889)	(3,165)
Net derivatives
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of liabilities from Level 2 to Level 3	13,200	15,400
Transfers of liabilities from Level 3 to Level 2	14,500	9,700
Net gains on Level 3 liabilities (realized and unrealized)	16,020	4,833
Structured Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of liabilities from Level 2 to Level 3	8,600	16,100
Transfers of liabilities from Level 3 to Level 2	39,100	14,900
Residential mortgage-backed securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 3 to Level 2		14,600
Net losses on Level 3 assets (realized and unrealized)	(167)	$ (202)
Net gains on Level 3 liabilities (realized and unrealized)	$ 0