Fair Value Measurements and Fair Value of Financial Instruments, Assets Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Jun. 30, 2020
Assets [Abstract]
Securities available-for-sale	$ 404,186	$ 226,709
Equity securities	286	267
Recurring [Member]
Assets [Abstract]
Securities available-for-sale	404,186	226,709
Equity securities	286	267
Total securities measured at fair value	404,472	226,976
Recurring [Member] \| U.S. Government Sponsored Enterprises [Member]
Assets [Abstract]
Securities available-for-sale	12,633	504
Recurring [Member] \| U.S. Treasury Securities [Member]
Assets [Abstract]
Securities available-for-sale	19,620
Recurring [Member] \| State and Political Subdivisions [Member]
Assets [Abstract]
Securities available-for-sale	210,014	177,107
Recurring [Member] \| Mortgage-backed Securities-Residential [Member]
Assets [Abstract]
Securities available-for-sale	39,416	15,528
Recurring [Member] \| Mortgage-backed Securities-Multi-family [Member]
Assets [Abstract]
Securities available-for-sale	119,363	28,910
Recurring [Member] \| Corporate Debt Securities [Member]
Assets [Abstract]
Securities available-for-sale	3,140	4,660
Recurring [Member] \| Level 1 [Member]
Assets [Abstract]
Securities available-for-sale	3,140	4,660
Equity securities	286	267
Total securities measured at fair value	3,426	4,927
Recurring [Member] \| Level 1 [Member] \| U.S. Government Sponsored Enterprises [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 1 [Member] \| U.S. Treasury Securities [Member]
Assets [Abstract]
Securities available-for-sale	0
Recurring [Member] \| Level 1 [Member] \| State and Political Subdivisions [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 1 [Member] \| Mortgage-backed Securities-Residential [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 1 [Member] \| Mortgage-backed Securities-Multi-family [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 1 [Member] \| Corporate Debt Securities [Member]
Assets [Abstract]
Securities available-for-sale	3,140	4,660
Recurring [Member] \| Level 2 [Member]
Assets [Abstract]
Securities available-for-sale	401,046	222,049
Equity securities	0	0
Total securities measured at fair value	401,046	222,049
Recurring [Member] \| Level 2 [Member] \| U.S. Government Sponsored Enterprises [Member]
Assets [Abstract]
Securities available-for-sale	12,633	504
Recurring [Member] \| Level 2 [Member] \| U.S. Treasury Securities [Member]
Assets [Abstract]
Securities available-for-sale	19,620
Recurring [Member] \| Level 2 [Member] \| State and Political Subdivisions [Member]
Assets [Abstract]
Securities available-for-sale	210,014	177,107
Recurring [Member] \| Level 2 [Member] \| Mortgage-backed Securities-Residential [Member]
Assets [Abstract]
Securities available-for-sale	39,416	15,528
Recurring [Member] \| Level 2 [Member] \| Mortgage-backed Securities-Multi-family [Member]
Assets [Abstract]
Securities available-for-sale	119,363	28,910
Recurring [Member] \| Level 2 [Member] \| Corporate Debt Securities [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 3 [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Equity securities	0	0
Total securities measured at fair value	0	0
Recurring [Member] \| Level 3 [Member] \| U.S. Government Sponsored Enterprises [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 3 [Member] \| U.S. Treasury Securities [Member]
Assets [Abstract]
Securities available-for-sale	0
Recurring [Member] \| Level 3 [Member] \| State and Political Subdivisions [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 3 [Member] \| Mortgage-backed Securities-Residential [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 3 [Member] \| Mortgage-backed Securities-Multi-family [Member]
Assets [Abstract]
Securities available-for-sale	0	0
Recurring [Member] \| Level 3 [Member] \| Corporate Debt Securities [Member]
Assets [Abstract]
Securities available-for-sale	$ 0	$ 0

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121558606&loc=SL82898722-210454

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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