SEGMENT REPORTING (Financial Statements Information) (Detail) - USD ($) $ in Thousands		3 Months Ended												12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jul. 31, 2016	Mar. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Net interest income		$ 8,053	$ 9,539	$ 9,507	$ 8,723	$ 6,989	$ 7,752	$ 7,532	$ 7,187	$ 6,158	$ 6,705	$ 6,307	$ 6,119	$ 35,822	$ 29,460	$ 25,289
Net gains on sales of loans, SBA														5,493	4,204	715
Noncash items:
Provision for loan losses		462	254	266	371	306	299	321	375	0	209	303	125	1,353	1,301	637
Depreciation and amortization														1,373	1,164	1,461
Income tax expense (benefit)	$ 619	622	766	696	338	$ 681	840	$ 586	$ 413	$ 467	1,211	$ (4,389)	$ 389	2,422	2,520	(2,322)
Segment profit		$ 3,406	2,744	$ 3,106	$ 1,646									12,336	9,313	7,911
Segment assets			1,034,406				891,133				796,516			1,034,406	891,133	796,516
Core Banking Segment [Member]
Net interest income														32,812	27,637	24,880
Net gains on sales of loans, SBA														0	0	0
Noncash items:
Provision for loan losses														(69)	868	501
Depreciation and amortization														1,323	1,120	1,426
Income tax expense (benefit)														2,825	2,754	(2,045)
Segment profit														9,050	7,109	9,604
Segment assets			1,025,135				885,669				785,287			1,025,135	885,669	785,287
SBA Lending Segment [Member]
Net interest income														3,012	1,802	390
Net gains on sales of loans, SBA														5,493	4,204	715
Noncash items:
Provision for loan losses														1,422	433	136
Depreciation and amortization														50	44	35
Income tax expense (benefit)														0	0	0
Segment profit														2,968	1,924	(1,830)
Segment assets			66,970				51,821				11,954			66,970	51,821	11,954
Other Segment [Member]
Net interest income														(2)	21	19
Net gains on sales of loans, SBA														0	0	0
Noncash items:
Provision for loan losses														0	0	0
Depreciation and amortization														0	0	0
Income tax expense (benefit)														(403)	(234)	(277)
Segment profit														318	280	137
Segment assets			$ (57,699)				$ (46,357)				$ (725)			$ (57,699)	$ (46,357)	$ (725)