Loans and Allowance for Loan Losses, Activity and Allocation of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Jun. 30, 2017
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	$ 11,352	$ 10,421	$ 11,022	$ 9,485
Charge-offs	104	68	509	299
Recoveries	29	25	65	63
Provision	345	343	1,044	1,472
Balance, end of period	11,622	10,721	11,622	10,721
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	527		527		$ 436
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	11,095		11,095		10,586
Loans receivable, ending balance, impairment analysis individually evaluated	4,163		4,163		3,252
Loans receivable, ending balance, impairment analysis collectively evaluated	685,207		685,207		631,079
Residential Real Estate [Member] | Residential Real Estate [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	2,099	2,234	2,289	2,396
Charge-offs	25	0	96	90
Recoveries	0	0	0	0
Provision	5	29	(114)	(43)
Balance, end of period	2,079	2,263	2,079	2,263
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	359		359		278
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	1,720		1,720		2,011
Loans receivable, ending balance, impairment analysis individually evaluated	1,930		1,930		1,455
Loans receivable, ending balance, impairment analysis collectively evaluated	251,415		251,415		243,876
Residential Real Estate [Member] | Construction and Land [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	86	63	89	75
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	8	15	5	3
Balance, end of period	94	78	94	78
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	94		94		89
Loans receivable, ending balance, impairment analysis individually evaluated	0		0		0
Loans receivable, ending balance, impairment analysis collectively evaluated	8,153		8,153		7,160
Residential Real Estate [Member] | Multi-family [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	95	18	43	22
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	67	16	119	12
Balance, end of period	162	34	162	34
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	162		162		43
Loans receivable, ending balance, impairment analysis individually evaluated	0		0		0
Loans receivable, ending balance, impairment analysis collectively evaluated	14,201		14,201		9,199
Commercial Real Estate [Member] | Real Estate [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	5,904	5,365	5,589	4,541
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	52	141	367	965
Balance, end of period	5,956	5,506	5,956	5,506
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	80		80		135
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	5,876		5,876		5,454
Loans receivable, ending balance, impairment analysis individually evaluated	1,200		1,200		1,249
Loans receivable, ending balance, impairment analysis collectively evaluated	278,276		278,276		256,715
Commercial Real Estate [Member] | Construction [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	603	603	687	502
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	136	45	52	146
Balance, end of period	739	648	739	648
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	27		27		23
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	712		712		664
Loans receivable, ending balance, impairment analysis individually evaluated	176		176		176
Loans receivable, ending balance, impairment analysis collectively evaluated	30,319		30,319		28,254
Consumer Loan [Member] | Home Equity [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	312	257	234	309
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	0	(30)	78	(82)
Balance, end of period	312	227	312	227
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	61		61		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	251		251		234
Loans receivable, ending balance, impairment analysis individually evaluated	504		504		186
Loans receivable, ending balance, impairment analysis collectively evaluated	20,786		20,786		20,890
Consumer Loan [Member] | Consumer Installment [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	252	224	231	228
Charge-offs	79	68	256	209
Recoveries	29	25	65	60
Provision	(14)	(17)	148	85
Balance, end of period	188	164	188	164
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	188		188		231
Loans receivable, ending balance, impairment analysis individually evaluated	0		0		0
Loans receivable, ending balance, impairment analysis collectively evaluated	4,863		4,863		4,790
Commercial Loans [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	2,001	1,513	1,680	1,412
Charge-offs	0	0	157	0
Recoveries	0	0	0	3
Provision	(26)	58	452	156
Balance, end of period	1,975	1,571	1,975	1,571
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	1,975		1,975		1,680
Loans receivable, ending balance, impairment analysis individually evaluated	353		353		186
Loans receivable, ending balance, impairment analysis collectively evaluated	77,194		77,194		60,195
Unallocated [Member]
Activity of allowance for loan losses by loan category [Roll Forward]
Balance, beginning of period	0	144	180	0
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	117	86	(63)	230
Balance, end of period	117	$ 230	117	$ 230
Allocation of allowance for loan losses by loan category [Abstract]
Allowance for loan losses, ending balance, impairment analysis individually evaluated	0		0		0
Allowance for loan losses, ending balance, impairment analysis collectively evaluated	117		117		180
Loans receivable, ending balance, impairment analysis individually evaluated	0		0		0
Loans receivable, ending balance, impairment analysis collectively evaluated	$ 0		$ 0		$ 0