Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Commissions	$ 1,281,294	$ 1,541,900	$ 1,567,668
Principal transactions	365,507	327,761	351,633
Fees from related parties	14,734	14,856	25,754
Data, software and post-trade	96,389	89,963	81,920
Interest and dividend income	21,007	21,977	12,332
Other revenues	16,371	18,907	17,454
Total revenues	1,795,302	2,015,364	2,056,761
Expenses:
Compensation and employee benefits	853,165	1,271,340	1,132,557
Equity-based compensation and allocations of net income to limited partnership units and FPUs	251,071	256,164	183,545
Total compensation and employee benefits	1,104,236	1,527,504	1,316,102
Occupancy and equipment	157,491	188,322	192,837
Fees to related parties	25,662	24,030	23,618
Professional and consulting fees	68,775	67,884	74,072
Communications	108,096	117,502	121,646
Selling and promotion	49,215	38,048	38,234
Commissions and floor brokerage	58,277	64,708	59,376
Interest expense	57,932	69,329	76,607
Other expenses	87,431	80,888	89,045
Total expenses	1,717,115	2,178,215	1,991,537
Other income (losses), net:
Gains (losses) on divestitures and sale of investments	(1,029)	312,941	394
Gains (losses) on equity method investments	10,920	6,706	5,023
Other income (loss)	9,373	19,705	1,580
Total other income (losses), net	19,264	339,352	6,997
Income (loss) from operations before income taxes	97,451	176,501	72,221
Provision (benefit) for income taxes	38,584	23,013	21,303
Consolidated net income (loss)	58,867	153,488	50,918
Less: Net income (loss) attributable to noncontrolling interest in subsidiaries	10,155	29,481	5,856
Net income available to common stockholders	48,712	124,007	45,062
Basic earnings (loss) per share
Net income (loss) available to common stockholders	$ 48,712	$ 124,007	$ 45,062
Basic earnings (loss) per share (in dollars per share)	$ 0.13	$ 0.33	$ 0.12
Basic weighted-average shares of common stock outstanding (in shares)	371,561	379,215	361,736
Fully diluted earnings (loss) per share
Net income (loss) for fully diluted shares	$ 63,479	$ 173,995	$ 64,787
Fully diluted earnings (loss) per share (in dollars per share)	$ 0.13	$ 0.32	$ 0.12
Fully diluted weighted-average shares of common stock outstanding (in shares)	499,414	540,020	546,848