CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues:
Commissions	$ 2,257,553,000	$ 1,648,817,000	$ 1,464,524,000
Principal transactions	440,830,000	389,429,000	368,100,000
Fees from related parties	18,713,000	20,728,000	15,968,000
Data, network and post-trade	138,980,000	126,963,000	111,470,000
Interest and dividend income	53,825,000	56,223,000	45,422,000
Other revenues	31,559,000	20,658,000	19,917,000
Total revenues	2,941,460,000	2,262,818,000	2,025,401,000
Expenses:
Compensation and employee benefits	1,656,011,000	1,123,747,000	992,603,000
Equity-based compensation and allocations of net income to limited partnership units and FPUs	329,588,000	369,143,000	355,378,000
Total compensation and employee benefits	1,985,599,000	1,492,890,000	1,347,981,000
Occupancy and equipment	184,210,000	169,238,000	162,743,000
Fees to related parties	38,296,000	32,529,000	32,649,000
Professional and consulting fees	67,037,000	64,949,000	60,398,000
Communications	136,433,000	120,624,000	114,143,000
Selling and promotion	105,237,000	70,466,000	61,884,000
Commissions and floor brokerage	70,259,000	70,798,000	61,523,000
Interest expense	125,318,000	91,075,000	77,231,000
Other expenses	104,782,000	69,694,000	74,278,000
Total expenses	2,817,171,000	2,182,263,000	1,992,830,000
Other income (losses), net:
Gains (losses) on divestitures and sale of investments	66,718,000	38,769,000	0
Gains (losses) on equity method investments	8,328,000	8,430,000	9,152,000
Other income (loss)	14,412,000	45,389,000	15,986,000
Total other income (losses), net	89,458,000	92,588,000	25,138,000
Income (loss) from operations before income taxes	213,747,000	173,143,000	57,709,000
Provision (benefit) for income taxes	67,208,000	49,915,000	18,934,000
Consolidated net income (loss)	146,539,000	123,228,000	38,775,000
Less: Net income (loss) attributable to noncontrolling interest in subsidiaries	(8,423,000)	(3,760,000)	2,510,000
Net income (loss) available to common stockholders	154,962,000	126,988,000	36,265,000
Basic earnings (loss) per share
Net income (loss) attributable to common stockholders	$ 148,628,000	$ 121,215,000	$ 34,070,000
Basic earnings (loss) per share (in dollars per share)	$ 0.31	$ 0.26	$ 0.08
Basic weighted-average shares of common stock outstanding (in shares)	476,364	473,390	426,436
Fully diluted earnings (loss) per share
Net income (loss) for fully diluted shares	$ 148,675,000	$ 121,268,000	$ 33,943,000
Fully diluted earnings (loss) per share (in dollars per share)	$ 0.31	$ 0.25	$ 0.07
Fully diluted weighted-average shares of common stock outstanding (in shares)	480,950	479,142	489,989