Fair Value Measurements for Operating Entities and Consolidated Funds - Assets and Liabilities at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		$ 51,482		$ 62,977
Other investments		255,027		185,722
Other Investments, Consolidated Funds		192,670		175,769
Investments		2,511,403		2,439,131
Securities sold, not yet purchased, at fair value		728,115		451,836
Securities sold, not yet purchased, at fair value		728,115		451,836
Payable for derivative contracts, at fair value		76,160		60,761
Contingent Consideration Payable		37,953		30,896
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low		10,100		1,300
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High		35,100		40,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance Liability Value		42,837		36,766
Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance Liability Value		704		1,000		$ 0
Contingent liability payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance Liability Value		36,718		30,896		$ 3,070
Futures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		0		217
Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		64,634		6,151
Payable for derivative contracts, at fair value		43,560		26,409
Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value	[1]	49,102		60,066
Portfolio Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	[2]	133,454		114,504
Other Investments, Consolidated Funds	[2]	192,670		175,769
Carried interest
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	[2]	82,892		30,360
Equity Method Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	[2]	38,681		40,858
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring		2,063,706		2,077,640
Investment Sold, Not yet Purchased and Derivative Liability, at Fair Value		840,993		548,262
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring		1,847,389		1,993,268
Investment Sold, Not yet Purchased and Derivative Liability, at Fair Value		777,908		478,524
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring		151,125		39,180
Investment Sold, Not yet Purchased and Derivative Liability, at Fair Value		57,281		36,212
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring		127,461		48,432
Investment Sold, Not yet Purchased and Derivative Liability, at Fair Value		42,837		36,766
Fair Value, Measurements, Recurring | Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		699,894		425,448
Fair Value, Measurements, Recurring | Common Stock | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		699,894		425,448
Fair Value, Measurements, Recurring | Common Stock | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Common Stock | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		11,358		5,933
Fair Value, Measurements, Recurring | Corporate Bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Corporate Bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		10,654		4,933
Fair Value, Measurements, Recurring | Corporate Bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		704		1,000
Fair Value, Measurements, Recurring | Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		6,589		3,686
Fair Value, Measurements, Recurring | Preferred Stock | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		6,589		3,686
Fair Value, Measurements, Recurring | Preferred Stock | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Preferred Stock | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Warrants and Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		8,774		14,819
Fair Value, Measurements, Recurring | Warrants and Rights [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		8,774		14,819
Fair Value, Measurements, Recurring | Warrants and Rights [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Warrants and Rights [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Contingent liability payable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration Payable		36,718	[3]	30,896	[4]
Fair Value, Measurements, Recurring | Contingent liability payable | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration Payable		0	[3]	0	[4]
Fair Value, Measurements, Recurring | Contingent liability payable | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration Payable		0	[3]	0	[4]
Fair Value, Measurements, Recurring | Contingent liability payable | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration Payable	[4]			30,896
Fair Value, Measurements, Recurring | Futures | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				217
Fair Value, Measurements, Recurring | Futures | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				217
Fair Value, Measurements, Recurring | Futures | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Futures | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Currency forward | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		3,067		851
Fair Value, Measurements, Recurring | Currency forward | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		0		0
Fair Value, Measurements, Recurring | Currency forward | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		3,067		851
Fair Value, Measurements, Recurring | Currency forward | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		0		0
Fair Value, Measurements, Recurring | Swaps | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		6,527		23,169
Fair Value, Measurements, Recurring | Swaps | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		0		0
Fair Value, Measurements, Recurring | Swaps | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		43,560		26,409
Fair Value, Measurements, Recurring | Swaps | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		0		0
Derivative Liability, Fair Value, Amount Offset Against Collateral	[5]	(37,033)		(3,240)
Fair Value, Measurements, Recurring | Options | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		66,566		36,524
Fair Value, Measurements, Recurring | Options | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		62,651		33,604
Fair Value, Measurements, Recurring | Options | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		0		0
Fair Value, Measurements, Recurring | Options | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value		3,915		2,920
Fair Value, Measurements, Recurring | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		19,721		15,916
Fair Value, Measurements, Recurring | Government Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		19,721		15,916
Fair Value, Measurements, Recurring | Government Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Government Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		69,358		12,656
Fair Value, Measurements, Recurring | Preferred Stock | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		9,391		4,821
Fair Value, Measurements, Recurring | Preferred Stock | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0		0
Fair Value, Measurements, Recurring | Preferred Stock | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		59,967		7,835
Fair Value, Measurements, Recurring | Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		1,770,451		1,546,484
Fair Value, Measurements, Recurring | Common Stock | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		1,746,407		1,527,769
Fair Value, Measurements, Recurring | Common Stock | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		108		1,249
Fair Value, Measurements, Recurring | Common Stock | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		23,936		17,466
Fair Value, Measurements, Recurring | Convertible Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		6,040		2,500
Fair Value, Measurements, Recurring | Convertible Bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Convertible Bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Convertible Bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		6,040		2,500
Fair Value, Measurements, Recurring | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		86,503		25,500
Fair Value, Measurements, Recurring | Corporate Bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Corporate Bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		86,368		23,079
Fair Value, Measurements, Recurring | Corporate Bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		135		2,421
Fair Value, Measurements, Recurring | Trade Claims
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		9,205		7,320
Fair Value, Measurements, Recurring | Trade Claims | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Trade Claims | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Trade Claims | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		9,205		7,320
Fair Value, Measurements, Recurring | Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		12,623		1,067
Fair Value, Measurements, Recurring | Loans | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		0
Fair Value, Measurements, Recurring | Loans | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		0		1,067
Fair Value, Measurements, Recurring | Loans | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading		12,623		0
Fair Value, Measurements, Recurring | Warrants and Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		27,701		22,109
Fair Value, Measurements, Recurring | Warrants and Rights [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		21,154		21,515
Fair Value, Measurements, Recurring | Warrants and Rights [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0		0
Fair Value, Measurements, Recurring | Warrants and Rights [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		6,547		594
Fair Value, Measurements, Recurring | Derivative Assets | Currency forward
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		15
Fair Value, Measurements, Recurring | Derivative Assets | Currency forward | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		0
Fair Value, Measurements, Recurring | Derivative Assets | Currency forward | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		15
Fair Value, Measurements, Recurring | Derivative Assets | Currency forward | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		0
Fair Value, Measurements, Recurring | Derivative Assets | Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		2,365		2,911
Fair Value, Measurements, Recurring | Derivative Assets | Swaps | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		0		0
Fair Value, Measurements, Recurring | Derivative Assets | Swaps | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		64,634		6,151
Fair Value, Measurements, Recurring | Derivative Assets | Swaps | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		0		0
Derivative Asset, Fair Value, Amount Offset Against Collateral	[5]	(62,269)		(3,240)
Fair Value, Measurements, Recurring | Derivative Assets | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		49,102		60,066
Fair Value, Measurements, Recurring | Derivative Assets | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		48,851		59,730
Fair Value, Measurements, Recurring | Derivative Assets | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		0		0
Fair Value, Measurements, Recurring | Derivative Assets | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value		251		336
Fair Value, Measurements, Recurring | Operating Companies [Member] | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		1,500		1,950
Fair Value, Measurements, Recurring | Operating Companies [Member] | Government Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Operating Companies [Member] | Government Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		0		0
Fair Value, Measurements, Recurring | Operating Companies [Member] | Government Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities sold, not yet purchased, at fair value		1,500		1,950
Fair Value, Measurements, Recurring | Consolidated Funds | Currency forward | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				88
Fair Value, Measurements, Recurring | Consolidated Funds | Currency forward | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Currency forward | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				88
Fair Value, Measurements, Recurring | Consolidated Funds | Currency forward | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Options | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				750
Fair Value, Measurements, Recurring | Consolidated Funds | Options | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				750
Fair Value, Measurements, Recurring | Consolidated Funds | Options | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Options | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Equity Swap | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				3,931
Fair Value, Measurements, Recurring | Consolidated Funds | Equity Swap | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Equity Swap | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				3,931
Fair Value, Measurements, Recurring | Consolidated Funds | Equity Swap | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payable for derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				161,607
Fair Value, Measurements, Recurring | Consolidated Funds | Government Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				161,607
Fair Value, Measurements, Recurring | Consolidated Funds | Government Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				0
Fair Value, Measurements, Recurring | Consolidated Funds | Government Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				0
Fair Value, Measurements, Recurring | Consolidated Funds | Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity				4,393
Fair Value, Measurements, Recurring | Consolidated Funds | Preferred Stock | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity				0
Fair Value, Measurements, Recurring | Consolidated Funds | Preferred Stock | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity				0
Fair Value, Measurements, Recurring | Consolidated Funds | Preferred Stock | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity				4,393
Fair Value, Measurements, Recurring | Consolidated Funds | Common Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		4,816		200,306
Fair Value, Measurements, Recurring | Consolidated Funds | Common Stock | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		1,865		200,306
Fair Value, Measurements, Recurring | Consolidated Funds | Common Stock | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0		0
Fair Value, Measurements, Recurring | Consolidated Funds | Common Stock | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		2,951		0
Fair Value, Measurements, Recurring | Consolidated Funds | Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				3,405
Fair Value, Measurements, Recurring | Consolidated Funds | Corporate Bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				0
Fair Value, Measurements, Recurring | Consolidated Funds | Corporate Bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				3,405
Fair Value, Measurements, Recurring | Consolidated Funds | Corporate Bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Trading				0
Fair Value, Measurements, Recurring | Consolidated Funds | Warrants and Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		5,806		5,567
Fair Value, Measurements, Recurring | Consolidated Funds | Warrants and Rights [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0		0
Fair Value, Measurements, Recurring | Consolidated Funds | Warrants and Rights [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		0		0
Fair Value, Measurements, Recurring | Consolidated Funds | Warrants and Rights [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading Securities, Equity		$ 5,806		5,567
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Currency forward
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				3,302
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Currency forward | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Currency forward | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				3,302
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Currency forward | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Options
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				1,604
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Options | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				1,604
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Options | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Options | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Equity Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				927
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Equity Swap | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				0
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Equity Swap | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				927
Fair Value, Measurements, Recurring | Consolidated Funds | Derivative Assets | Equity Swap | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivable on derivative contracts, at fair value				$ 0

[1] Includes the volume of contracts for index, equity, commodity future and cash conversion options.

[2] In accordance with US GAAP, portfolio funds are measured at fair value using the net asset value per share (or its equivalent) as a practical expedient are not classified in the fair value hierarchy. Carried interest and equity method investments presented in the table above are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated statement of financial condition.

[3] In accordance with the terms of the purchase agreements for acquisitions that closed during the first quarter of 2019 and the fourth quarter of 2020, the Company is required to pay to the sellers a portion of future net income and/or revenues of the acquired businesses, if certain targets are achieved through the periods ended December 31, 2020 and December 31, 2023. For both the Quarton Acquisition and the MHT Acquisition, the Company estimated the contingent consideration liabilities using a combination of Monte Carlo and Discounted Cash Flow methods which require the Company to make estimates and assumptions regarding the future cash flows and profits. Changes in these estimates and assumptions could have a significant impact on the amounts recognized. The undiscounted amounts for the Quarton Acquisition can range from $10.1 million to $35.1 million. The undiscounted amounts for the MHT Acquisition have no minimum or maximum as it is calculated based on revenue.

[4] In accordance with the terms of the purchase agreements for acquisitions that closed during the second quarter of 2016 and the first quarter of 2019, the Company is required to pay to the sellers a portion of future net income and/or revenues of the acquired businesses, if certain targets are achieved through the periods ended December 31, 2019 and December 31, 2023, respectively. For the acquisition that closed during 2016, the Company estimated the contingent consideration liability using the income approach (discounted cash flow method) which requires the Company to make estimates and assumptions regarding the future cash flows and profits. For the acquisition that closed during 2019, the Company estimated the contingent consideration liability using the present value of the Monte Carlo simulated revenue. Changes in these estimates and assumptions could have a significant impact on the amounts recognized. The undiscounted amounts as of December 31, 2019 can range from $1.3 million to $40.0 million.

[5] Derivatives are reported on a net basis, by counterparty, when a legal right of offset exists under an enforceable netting agreement as well as net of cash collateral received or posted under enforceable credit support agreements. See Note 2g for further information on offsetting of derivative financial instruments.