Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues
Commissions	$ 51,818	$ 42,379	$ 153,202	$ 129,971
Information and post-trade services	7,125	1,896	18,020	5,557
Technology products and services	1,561	1,124	4,279	3,553
Investment income	112	251	288	821
Other	517	752	2,502	2,360
Total revenues	61,133	46,402	178,291	142,262
Expenses
Employee compensation and benefits	17,910	13,380	47,638	41,550
Depreciation and amortization	3,460	1,715	10,151	4,786
Technology and communications	4,509	3,206	11,700	9,041
Professional and consulting fees	4,540	3,006	13,278	8,397
Occupancy	1,205	595	3,172	1,813
Marketing and advertising	1,195	989	3,501	3,996
General and administrative	1,926	2,011	6,370	5,500
Total expenses	34,745	24,902	95,810	75,083
Income before income taxes from continuing operations	26,388	21,500	82,481	67,179
Provision for income taxes	8,129	7,792	29,388	26,322
Net income from continuing operations	18,259	13,708	53,093	40,857
(Loss) from discontinued operations, net of income taxes	(46)	(226)	(210)	(1,253)
Net income	$ 18,213	$ 13,482	$ 52,883	$ 39,604
Basic earnings per common share
Income from continuing operations	$ 0.49	$ 0.38	$ 1.44	$ 1.12
(Loss) from discontinued operations		$ (0.01)	$ (0.01)	$ (0.04)
Net income per common share	$ 0.49	$ 0.37	$ 1.43	$ 1.08
Diluted earnings per common share
Income from continuing operations	$ 0.48	$ 0.37	$ 1.41	$ 1.08
(Loss) from discontinued operations		$ (0.01)	$ (0.01)	$ (0.03)
Net income per common share	$ 0.48	$ 0.36	$ 1.40	$ 1.05
Cash dividends declared per common share	$ 0.13	$ 0.11	$ 0.39	$ 0.33
Weighted average common shares
Basic	36,919	36,500	36,854	36,521
Diluted	37,965	37,541	37,820	37,892