Loans and Allowance for Loan Losses, Activity and Allocation of Allowance for Loan Losses (Details) - USD ($)	3 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021
Allowance for Loan Losses [Abstract]
Threshold principal amount of nonaccrual loans evaluated individually for impairment	$ 100,000
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	19,668,000	$ 16,391,000
Charge-offs	201,000	61,000
Recoveries	38,000	23,000
Provision	988,000	1,243,000
Balance, end of period	20,493,000	17,596,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	410,000		$ 391,000
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	20,083,000		19,277,000
Loans receivable, ending balance, impairment analysis individually evaluated	6,070,000		6,295,000
Loans receivable, ending balance, impairment analysis collectively evaluated	$ 1,112,714,000		1,102,113,000
Smaller Business Loans [Member] | Unsecured [Member]
Allowance for Loan Losses [Abstract]
Threshold period to charge off loans against allowance for loan losses	90 days
Residential Real Estate [Member] | Residential Real Estate [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	$ 2,012,000	2,091,000
Charge-offs	0	0
Recoveries	0	3,000
Provision	(15,000)	(631,000)
Balance, end of period	1,997,000	1,463,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	102,000		103,000
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	1,895,000		1,909,000
Loans receivable, ending balance, impairment analysis individually evaluated	952,000		1,093,000
Loans receivable, ending balance, impairment analysis collectively evaluated	325,322,000		324,074,000
Residential Real Estate [Member] | Construction and Land [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	106,000	141,000
Charge-offs	0	0
Recoveries	0	0
Provision	14,000	(23,000)
Balance, end of period	120,000	118,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	120,000		106,000
Loans receivable, ending balance, impairment analysis individually evaluated	0		0
Loans receivable, ending balance, impairment analysis collectively evaluated	12,645,000		10,185,000
Residential Real Estate [Member] | Multi-family [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	186,000	176,000
Charge-offs	0	0
Recoveries	0	0
Provision	(86,000)	4,000
Balance, end of period	100,000	180,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	100,000		186,000
Loans receivable, ending balance, impairment analysis individually evaluated	0		0
Loans receivable, ending balance, impairment analysis collectively evaluated	43,530,000		41,951,000
Commercial Real Estate [Member] | Real Estate [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	13,049,000	8,634,000
Charge-offs	0	0
Recoveries	0	0
Provision	1,249,000	750,000
Balance, end of period	14,298,000	9,384,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	54,000		58,000
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	14,244,000		12,991,000
Loans receivable, ending balance, impairment analysis individually evaluated	1,233,000		1,226,000
Loans receivable, ending balance, impairment analysis collectively evaluated	509,884,000		471,661,000
Commercial Real Estate [Member] | Construction [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	1,535,000	2,053,000
Charge-offs	0	0
Recoveries	0	0
Provision	(337,000)	(92,000)
Balance, end of period	1,198,000	1,961,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	1,000		1,000
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	1,197,000		1,534,000
Loans receivable, ending balance, impairment analysis individually evaluated	102,000		102,000
Loans receivable, ending balance, impairment analysis collectively evaluated	$ 61,596,000		62,661,000
Consumer Loan [Member] | Unsecured [Member]
Allowance for Loan Losses [Abstract]
Threshold period to charge off loans against allowance for loan losses	90 days
Consumer Loan [Member] | Home Equity [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	$ 165,000	295,000
Charge-offs	0	0
Recoveries	0	0
Provision	(25,000)	(23,000)
Balance, end of period	140,000	272,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	45,000		73,000
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	95,000		92,000
Loans receivable, ending balance, impairment analysis individually evaluated	449,000		545,000
Loans receivable, ending balance, impairment analysis collectively evaluated	18,287,000		17,740,000
Consumer Loan [Member] | Consumer Installment [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	267,000	197,000
Charge-offs	104,000	61,000
Recoveries	37,000	20,000
Provision	90,000	194,000
Balance, end of period	290,000	350,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	290,000		267,000
Loans receivable, ending balance, impairment analysis individually evaluated	0		0
Loans receivable, ending balance, impairment analysis collectively evaluated	$ 4,897,000		4,942,000
Consumer Loan [Member] | Consumer Installment [Member] | Unsecured [Member]
Allowance for Loan Losses [Abstract]
Threshold period to charge off overdrawn deposit accounts against allowance for loan losses	60 days
Commercial Loans [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	$ 2,348,000	2,804,000
Charge-offs	97,000	0
Recoveries	1,000	0
Provision	98,000	1,064,000
Balance, end of period	2,350,000	$ 3,868,000
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	208,000		156,000
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	2,142,000		2,192,000
Loans receivable, ending balance, impairment analysis individually evaluated	3,334,000		3,329,000
Loans receivable, ending balance, impairment analysis collectively evaluated	$ 136,553,000		$ 168,899,000