Fair Value Disclosures - Additional Information (Details)	3 Months Ended
	Feb. 29, 2024 USD ($)	Feb. 28, 2023 USD ($)	Nov. 30, 2023 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	$ 11,200,000	$ 39,800,000
Transfers of assets from Level 3 to Level 2	59,400,000	31,100,000
Transfers of liabilities from Level 2 to Level 3	31,600,000	58,200,000
Transfers of liabilities from Level 3 to Level 2	24,600,000	37,200,000
Net gains/(losses) on Level 3 assets (realized and unrealized)	(17,900,000)	11,700,000
Net gains/(losses) on Level 3 liabilities (realized and unrealized)	(11,900,000)	(29,500,000)
Value of asset excluded from significant unobservable inputs	43,000,000		$ 45,600,000
Value of liability excluded from significant unobservable inputs	4,900,000		4,000,000
Aggregate fair value of loans and other receivables on nonaccrual status and/or 90 days or greater past due	67,300,000		98,100,000
Loans and other receivables greater than 90 days past due	54,000,000		37,600,000
Investment, other than temporary impairment	22,100,000
Fair value, assets			0
Equity securities without readily determinable fair value, amount	21,900,000		0
Realized and unrealized gains (loss)		(33,200,000)
Equity securities without readily determinable fair value, impairment loss	0	0
Golden Queen Mining Company
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investment, other than temporary impairment		22,100,000
Monashee
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Our total equity balance	21,900,000		$ 15,800,000
CDOs and CLOs
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net gains/(losses) on Level 3 assets (realized and unrealized)	$ 11,121,000	4,810,000
CDOs and CLOs | Level 3 | Minimum | Discount rate/yield | Discounted cash flows
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial instruments owned, measurement input	0.13		0.21
CDOs and CLOs | Level 3 | Maximum | Discount rate/yield | Discounted cash flows
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial instruments owned, measurement input	0.23		0.26
CDOs and CLOs | Level 3 | Weighted Average | Discount rate/yield | Discounted cash flows
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial instruments owned, measurement input	0.19		0.24
Corporate debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	$ 1,700,000	17,700,000
Transfers of assets from Level 3 to Level 2	13,000,000
Net gains/(losses) on Level 3 assets (realized and unrealized)	846,000	(1,715,000)
Net gains/(losses) on Level 3 liabilities (realized and unrealized)	0	28,000
Corporate debt securities | Level 3 | Discount rate/yield | Discounted cash flows
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial instruments owned, measurement input			0.11
Loans and other receivables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	6,500,000	13,900,000
Transfers of assets from Level 3 to Level 2	20,200,000	27,700,000
Net gains/(losses) on Level 3 assets (realized and unrealized)	(15,592,000)	446,000
Corporate equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	1,300,000	4,300,000
Transfers of assets from Level 3 to Level 2	9,100,000
Net gains/(losses) on Level 3 assets (realized and unrealized)	(197,000)	17,688,000
Net gains/(losses) on Level 3 liabilities (realized and unrealized)	7,000	135,000
Other ABS
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 2 to Level 3	1,700,000	3,900,000
Transfers of assets from Level 3 to Level 2	2,200,000	3,000,000
Net gains/(losses) on Level 3 assets (realized and unrealized)	$ (3,165,000)	(2,940,000)
Other ABS | Level 3 | Minimum | Discount rate/yield | Discounted cash flows
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial instruments owned, measurement input	0.09		0.10
Other ABS | Level 3 | Maximum | Discount rate/yield | Discounted cash flows
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial instruments owned, measurement input	0.20		0.21
Other ABS | Level 3 | Weighted Average | Discount rate/yield | Discounted cash flows
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial instruments owned, measurement input	0.17		0.18
Net derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of liabilities from Level 2 to Level 3	$ 15,400,000	34,100,000
Transfers of liabilities from Level 3 to Level 2	9,700,000	15,600,000
Net gains/(losses) on Level 3 liabilities (realized and unrealized)	4,833,000	(9,713,000)
Structured notes
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of liabilities from Level 2 to Level 3	16,100,000	24,100,000
Transfers of liabilities from Level 3 to Level 2	14,900,000	21,600,000
Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net gains/(losses) on Level 3 liabilities (realized and unrealized)	54,000	(120,000)
RMBS
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers of assets from Level 3 to Level 2	14,600,000
Net gains/(losses) on Level 3 assets (realized and unrealized)	(202,000)	(3,605,000)
Commercial mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net gains/(losses) on Level 3 assets (realized and unrealized)	(35,000)	(353,000)
Net gains/(losses) on Level 3 liabilities (realized and unrealized)	$ 0	$ 0