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	$ 145,837		$ 125,509		$ 446,498		$ 370,107
Principal transactions	122,583		102,474		341,153		311,420
Investment banking	92,851		71,743		289,199		208,342
Asset management and service fees	76,710		62,881		221,711		189,010
Interest	39,130		26,360		101,829		78,728
Other income	13,063		31,094		45,269		49,991
Total revenues	490,174		420,061		1,445,659		1,207,598
Interest expense	11,535		5,904		34,738		24,768
Net revenues	478,639	[1]	414,157	[1]	1,410,921	[1]	1,182,830	[1]
Non-interest expenses:
Compensation and benefits	326,020		264,458		958,179		751,992
Occupancy and equipment rental	41,288		32,596		116,090		94,776
Communications and office supplies	26,122		19,561		74,034		60,115
Commissions and floor brokerage	10,150		7,842		28,777		22,339
Other operating expenses	44,051		28,526		126,600		84,212
Total non-interest expenses	447,631		352,983		1,303,680		1,013,434
Income before income tax expense	31,008		61,174		107,241		169,396
Provision for income taxes	(43,921)		23,740		(13,541)		67,384
Income from continuing operations	74,929		37,434		120,782		102,012
Income/(loss) from discontinued operations, net of tax	(5,239)		276		(7,037)		(3,393)
Net income	$ 69,690		$ 37,710		$ 113,745		$ 98,619
Earnings per basic common share
Income from continuing operations	$ 1.16		$ 0.70		$ 1.91		$ 1.91
Income/(loss) from discontinued operations	$ (0.08)				$ (0.11)		$ (0.07)
Earnings per basic common share	$ 1.08		$ 0.70		$ 1.80		$ 1.84
Earnings per diluted common share
Income from continuing operations	$ 1.00		$ 0.60		$ 1.66		$ 1.62
Income/(loss) from discontinued operations	$ (0.07)				$ (0.10)		$ (0.05)
Earnings per diluted common share	$ 0.93		$ 0.60		$ 1.56		$ 1.57
Weighted average number of common shares outstanding:
Basic	64,706		53,601		63,133		53,471
Diluted	75,191		63,054		72,851		62,817

[1] No individual client accounted for more than 10 percent of total net revenues for the three and nine months ended September 30, 2013 or 2012.