SEGMENT INFORMATION, Information Concerning Operations (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			5
Revenues:
Total revenues	$ 1,340,918	$ 1,312,624	$ 2,642,444	$ 2,592,468
Pre-tax income excluding noncontrolling interests
Pre-tax income excluding noncontrolling interests	198,118	180,320	366,456	383,228
Net loss attributable to noncontrolling interests	(7,914)	(4,687)	(14,077)	(8,946)
Income including noncontrolling interests and before provision for income taxes	190,204	175,633	352,379	374,282
Net interest income (expense):
Net interest income	132,143	107,567	247,605	212,292
Total assets:
Total assets	27,753,211		27,753,211			$ 26,479,684
Goodwill:
Goodwill	313,005	295,486	313,005	295,486	$ 307,635	307,635	$ 295,486	$ 295,486
Private client group
Goodwill:
Goodwill	189,355	174,584	189,355	174,584	186,733	186,733	174,584	174,584
Capital markets
Goodwill:
Goodwill	123,650	120,902	123,650	120,902	$ 120,902	120,902	$ 120,902	$ 120,902
Operating segments | Private client group
Revenues:
Total revenues	883,019	873,634	1,757,464	1,722,877
Pre-tax income excluding noncontrolling interests
Pre-tax income excluding noncontrolling interests	83,232	75,420	152,372	168,164
Net interest income (expense):
Net interest income	24,572	21,696	47,498	43,759
Total assets:
Total assets	7,531,421		7,531,421			6,870,379
Goodwill:
Goodwill						187,000
Operating segments | Capital markets
Revenues:
Total revenues	241,127	238,921	470,774	474,095
Pre-tax income excluding noncontrolling interests
Pre-tax income excluding noncontrolling interests	28,087	20,848	53,255	48,501
Net interest income (expense):
Net interest income	2,311	2,034	4,976	4,127
Total assets:
Total assets	3,013,879		3,013,879			2,780,733
Goodwill:
Goodwill						121,000
Operating segments | Asset management
Revenues:
Total revenues	96,842	94,022	197,080	193,652
Pre-tax income excluding noncontrolling interests
Pre-tax income excluding noncontrolling interests	31,123	31,095	64,489	70,891
Net interest income (expense):
Net interest income	(12)	24	88	91
Total assets:
Total assets	171,216		171,216			187,378
Operating segments | RJ Bank
Revenues:
Total revenues	131,312	105,390	244,038	208,346
Pre-tax income excluding noncontrolling interests
Pre-tax income excluding noncontrolling interests	85,134	71,264	150,999	135,620
Net interest income (expense):
Net interest income	121,297	99,857	227,485	196,579
Total assets:
Total assets	15,012,816		15,012,816			14,191,566
Operating segments | Other
Revenues:
Total revenues	9,872	17,806	14,272	27,572
Pre-tax income excluding noncontrolling interests
Pre-tax income excluding noncontrolling interests	(29,458)	(18,307)	(54,659)	(39,948)
Net interest income (expense):
Net interest income	(16,025)	(16,044)	(32,442)	(32,264)
Total assets:
Total assets	2,023,879		2,023,879			$ 2,449,628
Intersegment eliminations
Revenues:
Total revenues	$ (21,254)	$ (17,149)	$ (41,184)	$ (34,074)