Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues
Revenues	$ 172,112	$ 162,093	$ 540,398	$ 533,891
Expenses
Employee compensation and benefits	44,805	40,878	137,996	129,698
Depreciation and amortization	15,302	13,964	45,716	38,840
Technology and communications	14,169	10,665	38,851	31,245
Professional and consulting fees	7,560	10,847	26,101	31,191
Occupancy	3,381	3,265	10,468	9,882
Marketing and advertising	1,797	1,821	6,535	6,153
Clearing costs	4,211	3,269	13,049	12,335
General and administrative	4,576	3,381	12,479	9,893
Total expenses	95,801	88,090	291,195	269,237
Operating income	76,311	74,003	249,203	264,654
Other income (expense)
Investment income	1,433	108	1,746	322
Interest expense	(138)	(314)	(648)	(676)
Equity in earnings of unconsolidated affiliate	869	0	1,060	0
Other, net	388	697	7,499	(1,952)
Total other income (expense)	2,552	491	9,657	(2,306)
Income before income taxes	78,863	74,494	258,860	262,348
Provision for income taxes	19,556	16,536	67,862	56,645
Net income	$ 59,307	$ 57,958	$ 190,998	$ 205,703
Net income per common share
Basic	$ 1.58	$ 1.54	$ 5.10	$ 5.49
Diluted	1.58	1.52	5.07	5.40
Cash dividends declared per common share	$ 0.70	$ 0.66	$ 2.10	$ 1.98
Weighted average shares outstanding
Basic	37,479	37,529	37,464	37,502
Diluted	37,567	38,084	37,666	38,114
Commissions [Member]
Revenues
Revenues	$ 153,164	$ 142,826	$ 482,740	$ 475,095
Information Services [Member]
Revenues
Revenues	9,711	9,608	28,916	28,614
Post-trade Services [Member]
Revenues
Revenues	9,000	9,444	28,056	29,553
Other [Member]
Revenues
Revenues	$ 237	$ 215	$ 686	$ 629