PREMISES, FURNITURE, AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Property, Plant and Equipment [Line Items]
Premises, furniture, and equipment, gross	$ 61,413	$ 56,075
Less: accumulated depreciation and amortization	(42,093)	(37,449)
Net book value	19,320	18,626
Depreciation expense of premises, furniture, and equipment	5,500	5,400	$ 4,600
Amortization expense on capitalized leases	100	200	$ 200
Land [Member]
Property, Plant and Equipment [Line Items]
Premises, furniture, and equipment, gross	1,578	1,578
Buildings [Member]
Property, Plant and Equipment [Line Items]
Premises, furniture, and equipment, gross	10,642	10,482
Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises, furniture, and equipment, gross	46,934	41,756
Capitalized Leases [Member]
Property, Plant and Equipment [Line Items]
Premises, furniture, and equipment, gross	$ 2,259	$ 2,259