Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Revenues:
Commissions	$ 148,648		$ 123,303
Principal transactions	107,244		116,233
Investment banking	78,379		70,438
Asset management and service fees	68,912		60,818
Interest	29,845		25,257
Other income	20,212		13,294
Total revenues	453,240		409,343
Interest expense	11,460		9,010
Net revenues	441,780	[1]	400,333	[1]
Non-interest expenses:
Compensation and benefits	315,727		254,704
Occupancy and equipment rental	34,048		30,791
Communications and office supplies	22,979		20,373
Commissions and floor brokerage	9,058		7,612
Other operating expenses	36,622		27,599
Total non-interest expenses	418,434		341,079
Income before income tax expense	23,346		59,254
Provision for income taxes	8,727		24,481
Net income	$ 14,619		$ 34,773
Earnings per common share:
Basic	$ 0.24		$ 0.65
Diluted	$ 0.21	[2]	$ 0.55	[2]
Weighted average number of common shares outstanding:
Basic	60,054		53,243
Diluted	69,189		62,669

[1] No individual client accounted for more than 10 percent of total net revenues for the three months ended March 31, 2013 or 2012.

[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.