Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues
Revenues	$ 846,268	$ 817,097	$ 752,547
Expenses
Employee compensation and benefits	248,537	235,880	206,926
Depreciation and amortization	76,699	73,824	70,557
Technology and communications	78,294	72,166	62,801
Professional and consulting fees	31,487	27,382	31,935
Occupancy	15,038	14,690	14,216
Marketing and advertising	11,204	11,713	11,049
Clearing costs	16,583	17,863	17,002
General and administrative	26,588	22,709	23,042
Total expenses	504,430	476,227	437,528
Operating income	341,838	340,870	315,019
Other income (expense)
Interest income	24,397	26,046	22,425
Interest expense	(1,487)	(1,601)	(1,983)
Equity in earnings of unconsolidated affiliate	457	1,395	735
Other, net	1,790	(6,164)	(3,496)
Total other income (expense)	25,157	19,676	17,681
Income before income taxes and equity in undistributed earnings of subsidiaries	366,995	360,546	332,700
Provision for income taxes	120,083	86,365	74,645
Net income	246,912	274,181	258,055
Less: income attributable to redeemable noncontrolling interest	(285)	0	0
Net income	$ 246,627	$ 274,181	$ 258,055
Net income per common share
Basic	$ 6.66	$ 7.29	$ 6.87
Diluted	6.64	7.28	6.85
Cash dividends declared per common share	$ 3.04	$ 2.96	$ 2.88
Weighted average shares outstanding
Basic	37,056	37,600	37,546
Diluted	37,137	37,672	37,654
Commissions [Member]
Revenues
Revenues	$ 734,623	$ 711,710	$ 662,964
Information Services [Member]
Revenues
Revenues	53,230	50,540	46,383
Post-trade Services [Member]
Revenues
Revenues	44,491	42,487	40,178
Technology Services [Member]
Revenues
Revenues	$ 13,924	$ 12,360	$ 3,022