Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues:
Commissions	$ 127,427	$ 138,315	$ 250,730	$ 294,101
Principal transactions	91,564	79,741	207,797	172,600
Investment banking	67,363	64,418	137,801	105,836
Asset management and service fees	65,311	56,981	126,129	114,661
Interest	27,181	21,229	52,438	40,085
Other income	5,418	4,556	18,712	10,812
Total revenues	384,264	365,240	793,607	738,095
Interest expense	9,857	6,383	18,867	12,625
Net revenues	374,407	358,857	774,740	725,470
Non-interest expenses:
Compensation and benefits	239,374	229,939	494,078	461,105
Occupancy and equipment rental	32,320	29,723	63,111	59,048
Communications and office supplies	20,797	18,515	41,170	37,360
Commissions and floor brokerage	7,747	6,894	15,359	13,543
Other operating expenses	30,295	69,911	57,894	99,855
Total non-interest expenses	330,533	354,982	671,612	670,911
Income before income tax expense	43,874	3,875	103,128	54,559
Provision for income taxes	17,738	459	42,219	19,745
Net income	$ 26,136	$ 3,416	$ 60,909	$ 34,814
Earnings per common share:
Basic	$ 0.49	$ 0.06	$ 1.14	$ 0.66
Diluted	$ 0.42	$ 0.05	$ 0.97	$ 0.55
Weighted average number of common shares outstanding:
Basic	53,569	52,932	53,406	52,734
Diluted	62,678	63,245	62,700	63,239