Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues
Commissions	$ 86,270	$ 81,456	$ 267,307	$ 246,788
Information and post-trade services	8,372	7,322	24,460	23,687
Investment income	964	534	2,551	1,469
Other	1,095	959	3,588	3,539
Total revenues	96,701	90,271	297,906	275,483
Expenses
Employee compensation and benefits	25,595	23,914	78,417	74,256
Depreciation and amortization	4,583	4,325	14,066	13,546
Technology and communications	5,035	4,245	14,442	12,826
Professional and consulting fees	5,547	4,342	13,912	12,449
Occupancy	1,795	1,220	4,621	3,606
Marketing and advertising	2,089	2,140	6,757	5,742
Clearing costs	1,476	1,035	4,320	4,754
General and administrative	3,364	2,696	8,974	7,029
Total expenses	49,484	43,917	145,509	134,208
Income before income taxes	47,217	46,354	152,397	141,275
Provision for income taxes	13,087	15,436	37,781	48,268
Net income	$ 34,130	$ 30,918	$ 114,616	$ 93,007
Net income per common share
Basic	$ 0.93	$ 0.84	$ 3.11	$ 2.52
Diluted	0.90	0.82	3.01	2.46
Cash dividends declared per common share	$ 0.33	$ 0.26	$ 0.99	$ 0.78
Weighted average shares outstanding
Basic	36,865	36,889	36,856	36,847
Diluted	38,019	37,792	38,069	37,738