Deposits: Schedule of Interest Expense on Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Deposits [Abstract]
NOW checking	$ 451	$ 460	$ 456
Savings	85	78	64
Money market	722	434	327
Certificates of deposit	1,520	1,246	1,194
Total	$ 2,778	$ 2,218	$ 2,041