Consolidated Statements of Operations (USD $) In Thousands, except Per Share data	3 Months Ended				6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Revenues:
Commissions	$ 138,315		$ 103,634		$ 294,101		$ 208,669
Principal transactions	79,741		122,923		172,600		240,343
Investment banking	64,418		41,252		105,836		75,473
Asset management and service fees	56,981		44,138		114,661		85,241
Interest	21,229		14,654		40,085		29,301
Other income	4,556		3,757		10,812		5,702
Total revenues	365,240		330,358		738,095		644,729
Interest expense	6,383		2,349		12,625		4,690
Net revenues	358,857	[1]	328,009	[1]	725,470	[1]	640,039	[1]
Non-interest expenses:
Compensation and benefits	229,939		216,907		461,105		423,149
Occupancy and equipment rental	29,723		26,595		59,048		51,453
Communications and office supplies	18,515		15,925		37,360		30,343
Commissions and floor brokerage	6,894		5,272		13,543		11,016
Other operating expenses	69,911		27,365		99,855		48,568
Total non-interest expenses	354,982		292,064		670,911		564,529
Income before income tax expense	3,875		35,945		54,559		75,510
Provision for income taxes	459		14,836		19,745		30,661
Net income	$ 3,416		$ 21,109		$ 34,814		$ 44,849
Earnings per common share:
Basic	$ 0.06		$ 0.46		$ 0.66		$ 0.97
Diluted	$ 0.05	[2]	$ 0.40	[2]	$ 0.55	[2]	$ 0.85	[2]
Weighted average number of common shares outstanding:
Basic	52,932		46,257		52,734		46,168
Diluted	63,245		52,351		63,239		52,459

[1] No individual client accounted for more than 10 percent of total net revenues for the three and six months ended June 30, 2011 or 2010.

[2] Diluted earnings per share is computed on the basis of the weighted average number of shares of common stock plus the effect of dilutive potential common shares outstanding during the period using the treasury stock method. Diluted earnings per share include stock options and units.