Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Revenues	$ 210,318	$ 203,169
Expenses
Employee compensation and benefits	61,264	52,315
Depreciation and amortization	18,200	16,461
Technology and communications	17,051	14,999
Professional and consulting fees	6,395	7,127
Occupancy	3,425	3,611
Marketing and advertising	1,833	2,995
Clearing costs	4,911	4,545
General and administrative	4,739	5,760
Total expenses	117,818	107,813
Operating income	92,500	95,356
Other income (expense)
Interest income	5,973	4,249
Interest expense	(316)	(130)
Equity in earnings of unconsolidated affiliate	370	204
Other, net	(1,810)	(1,484)
Total other income (expense)	4,217	2,839
Income before income taxes	96,717	98,195
Provision for income taxes	24,102	24,567
Net income	$ 72,615	$ 73,628
Net income per common share
Basic	$ 1.92	$ 1.96
Diluted	1.92	1.96
Cash dividends declared per common share	$ 0.74	$ 0.72
Weighted average shares outstanding
Basic	37,740	37,478
Diluted	37,790	37,645
Commissions [Member]
Revenues
Revenues	$ 184,873	$ 181,991
Information Services [Member]
Revenues
Revenues	11,881	11,010
Post-trade Services [Member]
Revenues
Revenues	10,730	9,980
Technology Services [Member]
Revenues
Revenues	$ 2,834	$ 188