Loans and Allowance for Credit Losses - Credit risk profile based on rating and payment activity (Details) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
PCD loans receivable, net of ACL	$ 36,400,000	$ 37,400,000
Watch
Financing Receivable, Credit Quality Indicator [Line Items]
PCD loans receivable, net of ACL	11,800,000	12,700,000
Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
PCD loans receivable, net of ACL	0	0
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
PCD loans receivable, net of ACL	6,800,000	6,300,000
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
PCD loans receivable, net of ACL	$ 0	$ 0