Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Commissions	$ 66,412	$ 54,315	$ 133,430	$ 106,304
Information and post-trade services	7,632	7,962	15,311	16,041
Technology products and services	762	1,987	2,182	4,023
Investment income	190	138	373	284
Other	495	562	966	1,710
Total revenues	75,491	64,964	152,262	128,362
Expenses
Employee compensation and benefits	20,593	18,421	41,767	37,030
Depreciation and amortization	4,603	4,351	9,215	8,472
Technology and communications	3,967	4,449	8,305	8,941
Professional and consulting fees	3,011	3,426	6,293	7,398
Occupancy	1,232	1,102	2,224	2,191
Marketing and advertising	1,764	1,800	2,956	3,009
General and administrative	3,262	2,344	5,941	4,542
Total expenses	38,432	35,893	76,701	71,583
Income before income taxes	37,059	29,071	75,561	56,779
Provision for income taxes	12,821	10,880	26,730	21,113
Net income	$ 24,238	$ 18,191	$ 48,831	$ 35,666
Net income per common share
Basic	$ 0.66	$ 0.49	$ 1.33	$ 0.96
Diluted	0.64	0.48	1.30	0.94
Cash dividends declared per common share	$ 0.20	$ 0.16	$ 0.40	$ 0.32
Weighted average shares outstanding
Basic	36,699	37,015	36,703	37,068
Diluted	37,642	37,942	37,634	38,019