Loans, Allowance for Loan Losses and Impaired Loans - Schedule of Accounts, Notes, Loans and Financing Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Loans receivable
Ending balance of originated loans	$ 762,693	$ 732,995
Performing loans
Loans receivable
TDR loans	5,704	5,230
Other loans	748,662	719,725
Ending balance of originated loans	754,366	724,955
Nonperforming loans
Loans receivable
TDR loans	2,714	621
Other loans	5,613	7,419
Ending balance of originated loans	8,327	8,040
Residential real estate:
Loans receivable
Ending balance of originated loans	209,781	247,634
Residential real estate: | Performing loans
Loans receivable
TDR loans	3,468	3,085
Other loans	203,457	242,198
Ending balance of originated loans	206,925	245,283
Residential real estate: | Nonperforming loans
Loans receivable
TDR loans	531	593
Other loans	2,325	1,758
Ending balance of originated loans	2,856	2,351
Commercial/Agricultural real estate:
Loans receivable
Ending balance of originated loans	353,020	273,900
Commercial/Agricultural real estate: | Performing loans
Loans receivable
TDR loans	1,646	1,890
Other loans	348,238	268,619
Ending balance of originated loans	349,884	270,509
Commercial/Agricultural real estate: | Nonperforming loans
Loans receivable
TDR loans	694	0
Other loans	2,442	3,391
Ending balance of originated loans	3,136	3,391
Consumer non-real estate:
Loans receivable
Ending balance of originated loans	97,089	132,337
Consumer non-real estate: | Performing loans
Loans receivable
TDR loans	109	167
Other loans	96,694	131,695
Ending balance of originated loans	96,803	131,862
Consumer non-real estate: | Nonperforming loans
Loans receivable
TDR loans	17	28
Other loans	269	447
Ending balance of originated loans	286	475
Commercial/Agricultural non-real estate:
Loans receivable
Ending balance of originated loans	102,803	79,124
Commercial/Agricultural non-real estate: | Performing loans
Loans receivable
TDR loans	481	88
Other loans	100,273	77,213
Ending balance of originated loans	100,754	77,301
Commercial/Agricultural non-real estate: | Nonperforming loans
Loans receivable
TDR loans	1,472	0
Other loans	577	1,823
Ending balance of originated loans	$ 2,049	$ 1,823