Fair Value Measurements - Schedule of financial instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020
Financial assets
Cash and cash equivalents	$ 123,592	$ 54,245
Interest-bearing time deposits	979	974
Stock in FHLB	5,873	6,390
Stock in Federal Reserve Bank of St. Louis	5,031	4,363
Loans receivable, net	2,200,244	2,141,929
Accrued interest receivable	10,079	12,116
Financial liabilities
Deposits	2,330,803	2,184,847
Advances from FHLB	57,529	70,024
Accrued interest payable	779	1,646
Subordinated debt	15,243	15,142
Level 1
Financial assets
Cash and cash equivalents	123,592	54,245
Financial liabilities
Deposits	1,768,217	1,508,740
Level 2
Financial assets
Interest-bearing time deposits	979	974
Stock in FHLB	5,873	6,390
Stock in Federal Reserve Bank of St. Louis	5,031	4,363
Accrued interest receivable	10,079	12,116
Financial liabilities
Advances from FHLB	58,587	72,136
Accrued interest payable	779	1,646
Level 3
Financial assets
Loans receivable, net	2,218,762	2,143,823
Financial liabilities
Deposits	565,123	676,816
Subordinated debt	$ 15,468	$ 11,511