FHLB Advances and Other Borrowings - Narrative (Details)	12 Months Ended
Sep. 30, 2020 USD ($)
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
FHLB advances callable as of August 7, 2020 and quarterly thereafter	$ 100,000,000
Federal Home Loan Bank of Des Moines
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, percent of assets	45.00%

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with the earlier of contractual maturity or next call date within the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_FederalHomeLoanBankAdvancesEarlierOfContractualMaturityOrNextCallDateInNextRollingTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant