Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues
Commissions	$ 65,178	$ 54,462	$ 198,608	$ 160,766
Information and post-trade services	7,671	7,600	22,982	23,641
Technology products and services	683	1,562	2,865	5,585
Investment income	248	132	621	416
Other	412	489	1,378	2,199
Total revenues	74,192	64,245	226,454	192,607
Expenses
Employee compensation and benefits	21,002	18,589	62,769	55,619
Depreciation and amortization	4,642	4,482	13,857	12,954
Technology and communications	3,891	4,359	12,196	13,300
Professional and consulting fees	3,210	3,514	9,503	10,912
Occupancy	1,246	1,127	3,470	3,318
Marketing and advertising	1,304	1,331	4,260	4,340
General and administrative	3,544	2,575	9,485	7,117
Total expenses	38,839	35,977	115,540	107,560
Income before income taxes	35,353	28,268	110,914	85,047
Provision for income taxes	12,638	10,764	39,368	31,877
Net income	$ 22,715	$ 17,504	$ 71,546	$ 53,170
Net income per common share
Basic	$ 0.62	$ 0.47	$ 1.95	$ 1.44
Diluted	0.60	0.46	1.90	1.40
Cash dividends declared per common share	$ 0.20	$ 0.16	$ 0.60	$ 0.48
Weighted average shares outstanding
Basic	36,681	36,856	36,695	36,997
Diluted	37,643	37,805	37,636	37,947