LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR LOAN LOSSES (Schedule of Activity in the Allowance for Loan Losses by Loan Category) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2018	Jun. 30, 2017
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	$ 3,769	$ 3,537	$ 3,475	$ 3,313	$ 3,170	$ 3,056	$ 3,475	$ 3,056
Charge-offs	(64)	(25)	(297)	(248)	(278)	(255)
Recoveries	4		109	5	18	39
Provision	276	256	250	315	403	330	782	1,048
Balance at the end of period	3,985	3,769	3,537	3,385	3,313	3,170	3,985	3,385
One-to four-family residential [Member]
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	533	563	587	647	524	542	587	542
Charge-offs	(61)	(25)	(127)	(39)	(52)	(18)
Recoveries	4		82			35
Provision	58	(5)	21	(49)	175	(35)
Balance at the end of period	534	533	563	559	647	524	534	559
Commercial real estate [Member]
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	1,418	1,299	1,277	1,108	1,152	1,075	1,277	1,075
Charge-offs
Recoveries			23
Provision	70	119	(1)	65	(44)	77
Balance at the end of period	1,488	1,418	1,299	1,173	1,108	1,152	1,488	1,173
Construction [Member]
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	442	384	490	368	368	361	490	361
Charge-offs
Recoveries			3	3	3	3
Provision	70	58	(109)		(3)	4
Balance at the end of period	512	442	384	371	368	368	512	371
Home equity lines of credit [Member]
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	112	131	57	67	71	71	57	71
Charge-offs
Recoveries					14
Provision	4	(19)	74	(11)	(18)
Balance at the end of period	116	112	131	56	67	71	116	56
Commercial business [Member]
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	1,158	1,052	956	1,012	914	976	956	976
Charge-offs			(170)	(209)	(226)	(237)
Recoveries			1	2	1	1
Provision	19	106	265	219	323	174
Balance at the end of period	1,177	1,158	1,052	1,024	1,012	914	1,177	1,024
Other [Member]
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	4	4	6	13	7	9	6	9
Charge-offs	(3)
Recoveries
Provision	3		(2)	(7)	6	(2)
Balance at the end of period	4	4	4	6	13	7	4	6
Unallocated [Member]
Activity in the allowance for loan losses by loan category:
Balance at beginning of period	102	104	102	98	134	22	102	22
Charge-offs
Recoveries
Provision	52	(2)	2	98	(36)	112
Balance at the end of period	$ 154	$ 102	$ 104	$ 196	$ 98	$ 134	$ 154	$ 196