Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues:
Commissions	$ 299,430	$ 367,016	$ 965,636	$ 1,192,004
Principal transactions	79,568	73,997	283,338	254,757
Fees from related parties	3,896	3,470	10,838	11,500
Data, software and post-trade	23,808	22,238	71,326	65,826
Interest and dividend income	4,110	3,042	15,506	17,535
Other revenues	5,755	3,984	12,143	12,151
Total revenues	416,567	473,747	1,358,787	1,553,773
Expenses:
Compensation and employee benefits	202,353	257,604	671,494	836,533
Equity-based compensation and allocations of net income to limited partnership units and FPUs	57,730	78,490	161,739	170,275
Total compensation and employee benefits	260,083	336,094	833,233	1,006,808
Occupancy and equipment	38,710	46,049	117,294	141,598
Fees to related parties	6,551	5,674	18,285	15,574
Professional and consulting fees	15,048	16,836	44,489	53,071
Communications	26,802	29,305	81,859	89,891
Selling and promotion	11,373	9,586	34,754	25,692
Commissions and floor brokerage	13,104	15,908	44,686	48,145
Interest expense	14,499	16,735	43,144	53,268
Other expenses	19,951	24,614	60,736	64,423
Total expenses	406,121	500,801	1,278,480	1,498,470
Other income (losses), net:
Gains (losses) on divestitures and sale of investments	(183)	92	(183)	0
Gains (losses) on equity method investments	3,230	1,816	8,762	4,605
Other income (loss)	5,545	4,513	6,958	11,843
Total other income (losses), net	8,592	6,421	15,537	16,448
Income (loss) from operations before income taxes	19,038	(20,633)	95,844	71,751
Provision (benefit) for income taxes	10,813	(6,692)	40,575	7,056
Consolidated net income (loss)	8,225	(13,941)	55,269	64,695
Less: Net income (loss) attributable to noncontrolling interest in subsidiaries	2,463	(2,539)	8,773	17,141
Net income (loss) available to common stockholders	5,762	(11,402)	46,496	47,554
Basic earnings (loss) per share
Net income (loss) available to common stockholders	$ 5,762	$ (11,402)	$ 46,496	$ 47,554
Basic earnings (loss) per share (in dollars per share)	$ 0.02	$ (0.03)	$ 0.13	$ 0.12
Basic weighted-average shares of common stock outstanding (in shares)	371,108	387,121	371,692	382,161
Fully diluted earnings (loss) per share
Net income (loss) for fully diluted shares	$ 7,370	$ (11,402)	$ 60,718	$ 56,033
Fully diluted earnings (loss) per share (in dollars per share)	$ 0.01	$ (0.03)	$ 0.12	$ 0.12
Fully diluted weighted-average shares of common stock outstanding (in shares)	496,985	387,121	501,958	452,083