Note 5 - Fair Value (Details Textual) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2022
Impaired Financing Receivable, Related Allowance	$ 0		$ 0		$ 0
Other Real Estate Owned, Fair Value Disclosure	0		0		0
Fair Value, Nonrecurring [Member] \| Impaired Loans [Member]
Impaired Financing Receivable, Related Allowance	0		0		$ 0
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	$ 0	$ 0	$ 0	$ 0

Amount of increase (decrease) in allowance for credit loss on financing receivable.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration