Fair Value Measurements for Operating Entities and Consolidated Funds - Fair Value Inputs, Unobservable Inputs, Quantitative Information (Details) $ in Thousands		Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) times	Dec. 31, 2020 USD ($)
Contingent liability payable
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Liability Value		$ 38,648	$ 62,223	$ 36,718
Trade Claims
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		5,440	2,988	8,713
Options (held long)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		143	234	251
Warrants and Rights
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		26,937	15,403	6,547
Corporate Bonds
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		3,409	2,419	$ 135
Level 3
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		278,011	182,287
Balance Liability Value		$ 39,368	$ 65,642
Level 3 | Contingent liability payable | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.068	0.07
Level 3 | Contingent liability payable | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.185	0.15
Level 3 | Contingent liability payable | Valuation Technique, Discounted Cash Flow | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.11	0.12
Level 3 | Contingent liability payable | Discount Cash Flow and Monte Carlo Technique
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Liability Value		$ 38,648	$ 62,223
Level 3 | Contingent liability payable | Volatility | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.21	0.20
Level 3 | Contingent liability payable | Volatility | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.24	0.24
Level 3 | Contingent liability payable | Volatility | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.22	0.22
Level 3 | Common and Preferred Stock | Discounted Cash Flow and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 61,807	$ 76,491
Level 3 | Common and Preferred Stock | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.115	0.125
Level 3 | Common and Preferred Stock | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.125	0.20
Level 3 | Common and Preferred Stock | Valuation Technique, Discounted Cash Flow | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.12	0.13
Level 3 | Common and Preferred Stock | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		3.7	6.25
Level 3 | Common and Preferred Stock | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		9.5	6.75
Level 3 | Common and Preferred Stock | Valuation, Market Approach | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		7.55	6.5
Level 3 | Trade Claims | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 1,876	$ 2,376
Level 3 | Options (held long) | Discounted Cash Flow and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 1,022	$ 234
Level 3 | Options (held long) | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.115	0.125
Level 3 | Options (held long) | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.125	0.135
Level 3 | Options (held long) | Valuation Technique, Discounted Cash Flow | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.12	0.13
Level 3 | Warrants and Rights | Discounted Cash Flow and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 10,351	$ 4,483
Level 3 | Warrants and Rights | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.115	0.125
Level 3 | Warrants and Rights | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.125	0.135
Level 3 | Warrants and Rights | Valuation Technique, Discounted Cash Flow | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.120	0.13
Level 3 | Warrants and Rights | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.0725	0.0625
Level 3 | Warrants and Rights | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.0775	0.0675
Level 3 | Warrants and Rights | Valuation, Market Approach | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.075	0.065
Level 3 | Warrants and Rights | Black Scholes Model | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.45	0.90
Level 3 | Warrants and Rights | Black Scholes Model | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		1.70	1
Level 3 | Warrants and Rights | Black Scholes Model | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.711	0.95
Level 3 | Corporate Bonds | Discounted Cash Flow and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 4,570
Level 3 | Corporate Bonds | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.115
Level 3 | Corporate Bonds | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.125
Level 3 | Corporate Bonds | Valuation Technique, Discounted Cash Flow | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.12
Level 3 | Corporate Bonds | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		7.25
Level 3 | Corporate Bonds | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		7.75
Level 3 | Corporate Bonds | Valuation, Market Approach | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		7.5
Level 3 | Other Investments
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value	[1]	$ 198,385	$ 98,703
Level 3 | Options (held long) | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		7.25	6.25
Level 3 | Options (held long) | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		7.75	6.75
Level 3 | Options (held long) | Valuation, Market Approach | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		7.5	6.5
Level 3 | Options (held short) | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.0401
Level 3 | Options (held short) | Valuation Technique, Discounted Cash Flow | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.0401
Fair Value, Measurements, Recurring | Level 3 | Options (held short) | Derivative Liabilities | Valuation Technique, Option Pricing Model
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Liability Value		$ 720	$ 3,419
Discount rate | Level 3 | Trade Claims | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.54	0.40
Discount rate | Level 3 | Trade Claims | Valuation Technique, Discounted Cash Flow | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.54	0.40
Volatility | Level 3 | Options (held long) | Valuation Technique, Option Pricing Model
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.45
Volatility | Level 3 | Options (held long) | Valuation Technique, Option Pricing Model | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.45
Volatility | Level 3 | Options (held short) | Valuation Technique, Option Pricing Model
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.35	0.35
Volatility | Level 3 | Options (held short) | Valuation Technique, Option Pricing Model | Weighted Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Measurement Input		0.35	0.35

[1] The quantitative disclosures exclude financial instruments for which the determination of fair value is based on prices from recent transactions.