Loans Receivable - Summary of Risk Category of Loans by Portfolio Segment (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Jun. 30, 2021
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1,294,081	$ 1,237,522
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,267,733	1,209,619
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,206	6,301
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,142	21,602
Residential Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	215,431	224,305
Residential Mortgages [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	213,685	219,901
Residential Mortgages [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	156	2,480
Residential Mortgages [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,590	1,924
Commercial Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	897,424	826,624
Commercial Mortgages [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	878,607	809,660
Commercial Mortgages [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,947	1,615
Commercial Mortgages [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	15,870	15,349
Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	16,894	10,151
Construction [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	15,781	9,038
Construction [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans		1,113
Construction [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,113
Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	141,427	150,658
Commercial Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	137,265	146,275
Commercial Loans [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	21	491
Commercial Loans [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,141	3,892
Home Equity Lines Of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	22,557	25,439
Home Equity Lines Of Credit [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	22,047	24,400
Home Equity Lines Of Credit [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	82	602
Home Equity Lines Of Credit [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	428	437
Consumer and Overdrafts [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	348	345
Consumer and Overdrafts [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 348	$ 345