Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		$ 96,834	$ 89,187	$ 82,778
Ending Balance		111,000	96,834	89,187
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	(175)	(313)	(339)
Net change	[1]	51	138	26
Ending Balance	[1]	(124)	(175)	(313)
Changes in fair value of available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	4	3	37
Net change	[1]	(23)	1	(34)
Ending Balance	[1]	(19)	4	3
Other-than-temporary impairment on held to maturity securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	(179)	(316)	(376)
Net change	[1]	74	137	60
Ending Balance	[1]	$ (105)	$ (179)	$ (316)

[1] All amounts are net of income taxes.