Loans and Allowance for Loan Losses (Allowance For Loan Losses) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Sep. 30, 2016
Changes in Allowance for Loan Losses:
Beginning balance	$ 7,718	$ 6,751	$ 7,122	$ 6,624
Provisions	321	303	1,002	428
Charge-offs	(66)	(144)	(192)	(257)
Recoveries	22	59	63	174
Ending balance	7,995	6,969	7,995	6,969
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					$ 191	$ 48
Collectively evaluated for impairment					7,804	7,074
Ending balance	7,995	6,751	7,995	6,969	7,995	7,122
Residential Real Estate [Member]
Changes in Allowance for Loan Losses:
Beginning balance	311	286	335	444
Provisions	201	113	211	(69)
Charge-offs	(41)	(114)	(80)	(170)
Recoveries	4	33	9	113
Ending balance	475	318	475	318
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					189	43
Collectively evaluated for impairment					286	292
Ending balance	475	286	475	318	475	335
Commercial Real Estate [Member]
Changes in Allowance for Loan Losses:
Beginning balance	5,870	4,595	5,160	4,327
Provisions	(386)	526	324	794
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	5,484	5,121	5,484	5,121
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					5,484	5,160
Ending balance	5,484	4,595	5,484	5,121	5,484	5,160
Multifamily [Member]
Changes in Allowance for Loan Losses:
Beginning balance	116	157	109	156
Provisions	(21)	(46)	(14)	(45)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	95	111	95	111
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					95	109
Ending balance	95	157	95	111	95	109
Construction [Member]
Changes in Allowance for Loan Losses:
Beginning balance	703	651	845	551
Provisions	117	92	(25)	192
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	820	743	820	743
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					820	845
Ending balance	820	651	820	743	820	845
Land and Land Development [Member]
Changes in Allowance for Loan Losses:
Beginning balance	267	345	295	369
Provisions	(66)	(32)	(94)	(56)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	201	313	201	313
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					201	295
Ending balance	201	345	201	313	201	295
Commercial Business [Member]
Changes in Allowance for Loan Losses:
Beginning balance	348	625	284	678
Provisions	461	(358)	536	(411)
Charge-offs	0	(10)	(25)	(10)
Recoveries	0	1	14	1
Ending balance	809	258	809	258
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					0	0
Collectively evaluated for impairment					809	284
Ending balance	809	625	809	258	809	284
Consumer [Member]
Changes in Allowance for Loan Losses:
Beginning balance	103	92	94	99
Provisions	(15)	8	64	23
Charge-offs	(25)	(20)	(87)	(77)
Recoveries	18	25	40	60
Ending balance	111	105	111	105
Ending Allowance Balance Attributable to Loans:
Individually evaluated for impairment					2	5
Collectively evaluated for impairment					109	89
Ending balance	$ 111	$ 92	$ 111	$ 105	$ 111	$ 94