Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues
Revenues	$ 203,169	$ 186,057
Expenses
Employee compensation and benefits	52,315	47,756
Depreciation and amortization	16,461	15,174
Technology and communications	14,999	12,192
Professional and consulting fees	7,127	9,621
Occupancy	3,611	3,387
Marketing and advertising	2,995	1,789
Clearing costs	4,545	4,575
General and administrative	5,760	3,459
Total expenses	107,813	97,953
Operating income	95,356	88,104
Other income (expense)
Interest income	4,249	59
Interest expense	(130)	(173)
Equity in earnings of unconsolidated affiliate	204	0
Other, net	(1,484)	2,429
Total other income (expense)	2,839	2,315
Income before income taxes	98,195	90,419
Provision for income taxes	24,567	25,650
Net income	$ 73,628	$ 64,769
Net income per common share
Basic	$ 1.96	$ 1.73
Diluted	1.96	1.71
Cash dividends declared per common share	$ 0.72	$ 0.70
Weighted average shares outstanding
Basic	37,478	37,384
Diluted	37,645	37,824
Commissions [Member]
Revenues
Revenues	$ 181,991	$ 166,113
Information Services [Member]
Revenues
Revenues	11,010	9,809
Post-trade Services [Member]
Revenues
Revenues	9,980	9,912
Other [Member]
Revenues
Revenues	$ 188	$ 223