Fair Value Measurements for Operating Entities and Consolidated Funds Fair Value Inputs, Unobservable Inputs, Quantitative Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Contingent liability payable
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Liability Value		$ 30,896	$ 3,070	$ 3,440
Corporate Bonds
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		2,421	0
Balance Liability Value		1,000	0
Trade Claims
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		7,320	5,543	5,950
Warrants and Rights [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		594	1,666	2,517
Options
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		336	0	$ 1,455
Level 3
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		48,432	54,914
Balance Liability Value		$ 36,766	5,166
Level 3 | Contingent liability payable | Monte Carlo [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		17.00%
Weighted average percent Fair Value technique		17.00%
Level 3 | Contingent liability payable | Market Approach, Income Approach and Replacement Cost Valuation Techniques [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Liability Value			$ 3,070
Level 3 | Contingent liability payable | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		15.00%	23.00%
Level 3 | Contingent liability payable | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		15.00%	21.00%
Level 3 | Contingent liability payable | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		22.00%	23.00%
Level 3 | Other Liabilities [Member] | Income Approach and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Liability Value	[1]	$ 2,950
Level 3 | Corporate Bonds | Income Approach and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		311
Level 3 | Common and Preferred Stock | Market Approach, Income Approach and Replacement Cost Valuation Techniques [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 10,876	$ 4,323
Level 3 | Common and Preferred Stock | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		10.40%	8.00%
Level 3 | Common and Preferred Stock | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		8.00%	8.00%
Level 3 | Common and Preferred Stock | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		11.25%	14.00%
Level 3 | Common and Preferred Stock | Valuation, Market Approach
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		675.00%	6.75%
Level 3 | Common and Preferred Stock | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		650.00%	650.00%
Level 3 | Common and Preferred Stock | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		700.00%	700.00%
Level 3 | Trade Claims | Market Approach, Income Approach and Replacement Cost Valuation Techniques [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 24	$ 25
Level 3 | Warrants and Rights [Member] | Income Approach and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 6,162
Level 3 | Warrants and Rights [Member] | Market Approach, Income Approach and Replacement Cost Valuation Techniques [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value			$ 1,666
Level 3 | Warrants and Rights [Member] | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		6.10%	7.80%
Level 3 | Warrants and Rights [Member] | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		6.00%	7.00%
Level 3 | Warrants and Rights [Member] | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		7.00%	9.00%
Level 3 | Other Investments | Income Approach and Market Approach Valuation Techniques
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value	[1]	$ 30,723
Level 3 | Other Investments | Market Approach, Income Approach and Replacement Cost Valuation Techniques [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value	[1]		$ 48,900
Level 3 | Options | Market Approach, Income Approach and Replacement Cost Valuation Techniques [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Asset Value		$ 336
Level 3 | Options | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		10.50%
Level 3 | Options | Valuation Technique, Discounted Cash Flow | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		9.75%
Level 3 | Options | Valuation Technique, Discounted Cash Flow | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		11.25%
Level 3 | Bonds | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		20.00%
Weighted average percent Fair Value technique		20.00%
Level 3 | Bonds | Probability of recovery valuation technique
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		2.30%
Level 3 | Bonds | Probability of recovery valuation technique | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		1.00%
Level 3 | Bonds | Probability of recovery valuation technique | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		3.00%
Level 3 | Options | Valuation, Market Approach
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		675.00%
Level 3 | Options | Valuation, Market Approach | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		650.00%
Level 3 | Options | Valuation, Market Approach | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		700.00%
Level 3 | Option | Options
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Balance Liability Value		$ 2,920
Fair Value, Measurements, Recurring | Level 3 | Option | Options | Market Approach, Income Approach and Replacement Cost Valuation Techniques [Member]
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Financial Liabilities Fair Value Disclosure			$ 2,096
Discount rate | Level 3 | Trade Claims | Valuation Technique, Discounted Cash Flow
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		20.00%	20.00%
Weighted average percent Fair Value technique		20.00%	20.00%
Volatility | Level 3 | Warrants and Rights [Member] | Market Approach Valuation Technique
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		30.00%
Weighted average percent Fair Value technique		0.00%
Volatility | Level 3 | Option | Market Approach Valuation Technique
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Weighted average percent Fair Value technique		35.00%	35.00%
Volatility | Level 3 | Option | Market Approach Valuation Technique | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		35.00%	35.00%
Volatility | Level 3 | Option | Market Approach Valuation Technique | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Fair value inputs		40.00%	40.00%

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