Consolidated Statements Of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Revenues:
Commissions		$ 165,775	$ 175,274
Principal transactions		97,782	116,857
Investment banking		176,362	126,852
Asset management and service fees		195,801	162,739
Interest		137,734	100,953
Other income		3,357	8,752
Total revenues		776,811	691,427
Interest expense		26,453	15,896
Net revenues	[1]	750,358	675,531
Non-interest expenses:
Compensation and benefits		457,893	436,387
Occupancy and equipment rental		57,595	52,545
Communications and office supplies		33,499	33,844
Commissions and floor brokerage		9,365	10,723
Other operating expenses		72,452	63,013
Total non-interest expenses		630,804	596,512
Income from operations before income tax expense		119,554	79,019
Provision for income taxes		30,793	13,507
Net income		88,761	65,512
Preferred dividends		2,344	2,344
Net income available to common shareholders		$ 86,417	$ 63,168
Earnings per common share:
Basic		$ 1.20	$ 0.92
Diluted		$ 1.06	$ 0.78
Weighted-average number of common shares outstanding:
Basic		71,999	68,386
Diluted		81,789	80,695
Cash dividends declared per common share		$ 0.12	$ 0

[1] No individual client accounted for more than 10 percent of total net revenues for the three months ended March 31, 2018 or 2017.