Securities (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2020 USD ($) Category	Jun. 30, 2020 USD ($)
Available-for-sale debt securities [Abstract]
Amortized cost	$ 267,558	$ 224,340
Gross unrealized gains	2,335	2,386
Gross unrealized losses	223	17
Estimated fair value	269,670	226,709
Held-to-maturity securities [Abstract]
Amortized cost	390,107	383,657
Gross unrealized gains	23,558	22,024
Gross unrealized losses	99	169
Estimated fair value	413,566	405,512
Total Securities [Abstract]
Amortized cost	657,665	607,997
Gross unrealized gains	25,893	24,410
Gross unrealized losses	322	186
Estimated fair value	$ 683,236	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		502
Gross unrealized gains		2
Gross unrealized losses		0
Estimated fair value		504
Held-to-maturity securities [Abstract]
Amortized cost	$ 2,000	2,000
Gross unrealized gains	4	11
Gross unrealized losses	0	0
Estimated fair value	2,004	2,011
State and Political Subdivisions [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	188,558	176,064
Gross unrealized gains	806	1,043
Gross unrealized losses	0	0
Estimated fair value	189,364	177,107
Held-to-maturity securities [Abstract]
Amortized cost	226,465	210,535
Gross unrealized gains	15,040	14,286
Gross unrealized losses	28	3
Estimated fair value	241,477	224,818
Mortgage-backed Securities-Residential [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	23,331	15,148
Gross unrealized gains	323	380
Gross unrealized losses	19	0
Estimated fair value	23,635	15,528
Held-to-maturity securities [Abstract]
Amortized cost	32,166	38,884
Gross unrealized gains	950	1,002
Gross unrealized losses	0	15
Estimated fair value	33,116	39,871
Mortgage-backed Securities-Multi-family [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	51,659	28,116
Gross unrealized gains	1,041	798
Gross unrealized losses	147	4
Estimated fair value	52,553	28,910
Held-to-maturity securities [Abstract]
Amortized cost	121,389	127,582
Gross unrealized gains	7,467	6,680
Gross unrealized losses	6	21
Estimated fair value	128,850	134,241
Corporate Debt Securities [Member]
Available-for-sale debt securities [Abstract]
Amortized cost	4,010	4,510
Gross unrealized gains	165	163
Gross unrealized losses	57	13
Estimated fair value	4,118	4,660
Held-to-maturity securities [Abstract]
Amortized cost	5,094	2,593
Gross unrealized gains	23	7
Gross unrealized losses	65	130
Estimated fair value	5,052	2,470
Other Securities [Member]
Held-to-maturity securities [Abstract]
Amortized cost	2,993	2,063
Gross unrealized gains	74	38
Gross unrealized losses	0	0
Estimated fair value	$ 3,067	$ 2,101