Securities (Details) $ in Thousands	9 Months Ended
	Mar. 31, 2021 USD ($) Category	Jun. 30, 2020 USD ($)
Available-for-sale debt securities [Abstract]
Amortized cost	$ 407,345	$ 224,340
Gross unrealized gains	1,389	2,386
Gross unrealized losses	4,548	17
Estimated fair value	404,186	226,709
Held-to-maturity securities [Abstract]
Amortized cost	444,073	383,657
Gross unrealized gains	21,160	22,024
Gross unrealized losses	814	169
Estimated fair value	464,419	405,512
Total Securities [Abstract]
Amortized cost	851,418	607,997
Gross unrealized gains	22,549	24,410
Gross unrealized losses	5,362	186
Estimated fair value	$ 868,605	632,221
Number of categories utilized under risk management approach of diversified investing | Category	3
U.S. Government Sponsored Enterprises [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	$ 13,081	502
Gross unrealized gains	0	2
Gross unrealized losses	448	0
Estimated fair value	12,633	504
Held-to-maturity securities [Abstract]
Amortized cost		2,000
Gross unrealized gains		11
Gross unrealized losses		0
Estimated fair value		2,011
U.S. Treasury Securities [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	19,699
Gross unrealized gains	0
Gross unrealized losses	79
Estimated fair value	19,620
State and Political Subdivisions [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	209,639	176,064
Gross unrealized gains	375	1,043
Gross unrealized losses	0	0
Estimated fair value	210,014	177,107
Held-to-maturity securities [Abstract]
Amortized cost	294,382	210,535
Gross unrealized gains	15,963	14,286
Gross unrealized losses	426	3
Estimated fair value	309,919	224,818
Mortgage-backed Securities-Residential [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	39,492	15,148
Gross unrealized gains	273	380
Gross unrealized losses	349	0
Estimated fair value	39,416	15,528
Held-to-maturity securities [Abstract]
Amortized cost	32,908	38,884
Gross unrealized gains	695	1,002
Gross unrealized losses	202	15
Estimated fair value	33,401	39,871
Mortgage-backed Securities-Multi-family [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	122,425	28,116
Gross unrealized gains	610	798
Gross unrealized losses	3,672	4
Estimated fair value	119,363	28,910
Held-to-maturity securities [Abstract]
Amortized cost	103,448	127,582
Gross unrealized gains	4,381	6,680
Gross unrealized losses	110	21
Estimated fair value	107,719	134,241
Corporate Debt Securities [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	3,009	4,510
Gross unrealized gains	131	163
Gross unrealized losses	0	13
Estimated fair value	3,140	4,660
Held-to-maturity securities [Abstract]
Amortized cost	7,849	2,593
Gross unrealized gains	58	7
Gross unrealized losses	76	130
Estimated fair value	7,831	2,470
Other Securities [Member]
Held-to-maturity securities [Abstract]
Amortized cost	5,486	2,063
Gross unrealized gains	63	38
Gross unrealized losses	0	0
Estimated fair value	$ 5,549	$ 2,101