Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues
Commissions	$ 79,093	$ 67,018
Information and post-trade services	7,779	7,679
Investment income	418	183
Other	1,283	1,891
Total revenues	88,573	76,771
Expenses
Employee compensation and benefits	24,527	21,174
Depreciation and amortization	4,681	4,612
Technology and communications	4,304	4,338
Professional and consulting fees	3,862	3,282
Occupancy	1,161	992
Marketing and advertising	1,778	1,192
General and administrative	3,890	2,679
Total expenses	44,203	38,269
Income before income taxes	44,370	38,502
Provision for income taxes	15,407	13,909
Net income	$ 28,963	$ 24,593
Net income per common share
Basic	$ 0.79	$ 0.67
Diluted	0.77	0.65
Cash dividends declared per common share	$ 0.26	$ 0.20
Weighted average shares outstanding
Basic	36,775	36,706
Diluted	37,671	37,626