Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues:
Commissions	$ 348,720	$ 309,542	$ 726,008	$ 666,206
Principal transactions	94,883	88,169	209,812	203,770
Fees from related parties	4,062	3,625	8,019	6,942
Data, network and post-trade	27,000	23,391	54,122	47,518
Interest and dividend income	13,371	8,961	18,686	11,396
Other revenues	5,044	2,068	9,300	6,388
Total revenues	493,080	435,756	1,025,947	942,220
Expenses:
Compensation and employee benefits	243,387	211,873	510,601	469,141
Equity-based compensation and allocations of net income to limited partnership units and FPUs	126,644	46,133	208,017	104,009
Total compensation and employee benefits	370,031	258,006	718,618	573,150
Occupancy and equipment	40,488	39,921	81,653	78,584
Fees to related parties	7,991	6,009	16,431	11,734
Professional and consulting fees	14,819	13,810	30,520	29,441
Communications	27,813	27,166	55,752	55,057
Selling and promotion	15,320	12,443	29,936	23,381
Commissions and floor brokerage	16,161	14,239	31,426	31,582
Interest expense	19,914	14,342	35,656	28,645
Other expenses	13,221	23,010	25,729	40,785
Total expenses	525,758	408,946	1,025,721	872,359
Other income (losses), net:
Gains (losses) on equity method investments	2,412	2,729	4,474	5,532
Other income (loss)	(1,011)	1,909	(2,746)	1,413
Total other income (losses), net	1,401	4,638	1,728	6,945
Income (loss) from operations before income taxes	(31,277)	31,448	1,954	76,806
Provision (benefit) for income taxes	(9,067)	15,105	2,994	29,762
Consolidated net income (loss)	(22,210)	16,343	(1,040)	47,044
Less: Net income (loss) attributable to noncontrolling interest in subsidiaries	(2,506)	1,581	(314)	6,310
Net income (loss) available to common stockholders	(19,704)	14,762	(726)	40,734
Basic earnings (loss) per share
Net income (loss) available to common stockholders	$ (19,704)	$ 14,762	$ (726)	$ 40,734
Basic earnings (loss) per share (in dollars per share)	$ (0.05)	$ 0.04	$ 0	$ 0.11
Basic weighted-average shares of common stock outstanding (in shares)	391,745	375,613	383,528	371,988
Fully diluted earnings (loss) per share
Net income (loss) for fully diluted shares	$ (19,704)	$ 19,710	$ (726)	$ 53,348
Fully diluted earnings (loss) per share (in dollars per share)	$ (0.05)	$ 0.04	$ 0	$ 0.11
Fully diluted weighted-average shares of common stock outstanding (in shares)	391,745	507,005	383,528	504,609