DERIVATIVE FINANCIAL INSTRUMENTS, Income Statement Location (Details) (Derivatives not designated as hedging instruments, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Net trading profits | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in Income	$ 2,403	$ (70)	$ 2,280	$ 579
Other revenues | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in Income	44	651	66	671
Other revenues | Forward foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) on derivatives recognized in Income	$ 8,683	$ 2,530	$ 12,305	$ 4,811