TRADING INSTRUMENTS AND TRADING INSTRUMENTS SOLD BUT NOT YET PURCHASED (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015
Trading Securities [Abstract]
Total debt securities	$ 644,638	$ 581,837
Derivative contracts	51,275	42,086
Equity securities	54,524	28,344
Brokered certificates of deposit	32,257	30,803
Other	16,759	7,481
Trading instruments	799,453	690,551
Financial Instruments Sold, Not yet Purchased, at Fair Value [Abstract]
Total debt securities	312,713	262,162
Derivative liability	7,639	20,239
Equity securities	4,958	3,098
Brokered certificates of deposit	0	0
Other	100	2,494
Instruments sold but not yet purchased	325,410	287,993
Municipal and provincial obligations
Trading Securities [Abstract]
Total debt securities	239,580	206,063
Financial Instruments Sold, Not yet Purchased, at Fair Value [Abstract]
Total debt securities	4	18,313
Corporate obligations
Trading Securities [Abstract]
Total debt securities	137,061	95,317
Financial Instruments Sold, Not yet Purchased, at Fair Value [Abstract]
Total debt securities	48,860	33,184
Government and agency obligations
Trading Securities [Abstract]
Total debt securities	133,487	115,947
Financial Instruments Sold, Not yet Purchased, at Fair Value [Abstract]
Total debt securities	260,727	205,658
Agency MBS and CMOs
Trading Securities [Abstract]
Total debt securities	98,577	117,570
Financial Instruments Sold, Not yet Purchased, at Fair Value [Abstract]
Total debt securities	3,122	5,007
Non-agency CMOs and ABS
Trading Securities [Abstract]
Total debt securities	35,933	46,940
Financial Instruments Sold, Not yet Purchased, at Fair Value [Abstract]
Total debt securities	$ 0	$ 0