Acquisitions - Additional information (Details) - USD ($)			1 Months Ended	7 Months Ended	12 Months Ended
	May 22, 2020	Nov. 21, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Noninterest expense					$ 54,452,000	$ 47,892,000	$ 42,973,000
Goodwill			$ 14,089,000	$ 14,089,000	14,089,000	14,089,000
Bargain purchase gain					$ 123,000
Core Deposit Intangible Assets Amortization Period					five to seven years
Central Federal Bancshares
Value of all cash transaction	$ 21,900,000
Cash consideration	9,100,000
Acquisition related costs			1,200,000
Noninterest expense			1,200,000
Finite-Lived Core Deposits, Gross			540,000		$ 540,000
Goodwill			$ 0		$ 0
Bargain purchase gain	123,000
Core Deposit Intangible Assets Amortization Period					P6Y
Diversified portfolio, loans	52,100,000
Fair value of portfolio	$ 662,000
Gideon Bancshares Company and First Commercial Bank
Acquisition related costs					$ 871,000
Noninterest expense					$ 14,000	$ 783,000	$ 75,000
Gideon Bancshares Company
Cash portion for each share converted upon completion of merger		$ 72.48
Number of shares issued upon the completion of merger		2.04
Number of shares issued		317,225
Cash consideration		$ 11,300,000
Goodwill		$ 1,000,000.0
Core Deposit Intangible Assets Amortization Period		P7Y
Diversified portfolio, loans		$ 154,000,000.0
Fair value of portfolio		9,700,000
Losses charged off		$ 25,500,000
Revenue from acquired business				4,100,000
Earnings from acquired business				$ 565,000