GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS, Net Amortizable Intangible Assets (Details) - USD ($) $ in Thousands			12 Months Ended
	Jul. 31, 2015	Apr. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Dec. 24, 2012
Finite-lived Intangible Assets [Roll Forward]
Amortizable net intangible assets (beginning of the period)			$ 58,775	$ 65,978	$ 61,135
Additions			18,838	408	14,414
Amortization expense			(8,286)	(7,611)	(9,571)
Impairment losses			0	0	0
Amortizable net intangible assets (end of the period)			69,327	58,775	65,978
Private client group
Finite-lived Intangible Assets [Roll Forward]
Amortizable net intangible assets (beginning of the period)			8,611	9,191	9,829
Additions			10,290	0	0
Amortization expense			(719)	(580)	(638)
Impairment losses			0	0	0
Amortizable net intangible assets (end of the period)			18,182	8,611	9,191
Capital markets
Finite-lived Intangible Assets [Roll Forward]
Amortizable net intangible assets (beginning of the period)			37,975	43,474	51,306
Additions			0	0	0
Amortization expense			(5,443)	(5,499)	(7,832)
Impairment losses			0	0	0
Amortizable net intangible assets (end of the period)			32,532	37,975	43,474
Asset Management
Finite-lived Intangible Assets [Roll Forward]
Amortizable net intangible assets (beginning of the period)			10,996	12,329	0
Additions			7,974	0	13,329
Amortization expense			(1,833)	(1,333)	(1,000)
Impairment losses			0	0	0
Amortizable net intangible assets (end of the period)			17,137	10,996	12,329
Business Combinations [Abstract]
Business acquisition, acquired interest (as a percentage)						45.00%
Portion of ClariVest attributable to others						55.00%
RJ Bank
Finite-lived Intangible Assets [Roll Forward]
Amortizable net intangible assets (beginning of the period)			1,193	984	0
Additions			574	408	1,085
Amortization expense			(291)	(199)	(101)
Impairment losses			0	0	0
Amortizable net intangible assets (end of the period)			$ 1,476	$ 1,193	$ 984
Useful life			10 years
The Producers Choice LLC | Private client group
Finite-lived Intangible Assets [Roll Forward]
Weighted average useful life	12 years 11 months 12 days
Cougar Global Investments Limited | Asset Management
Finite-lived Intangible Assets [Roll Forward]
Weighted average useful life		9 years 6 months