Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Jun. 30, 2019
Statement Of Financial Position [Abstract]
Held to maturity investment securities, fair value	$ 267,704	$ 346,243
Allowance for loan losses	$ 8,346	$ 5,664
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	10,000,000	10,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	200,000,000	200,000,000
Common Stock, shares, issued	18,712,295	18,712,295
Common Stock, shares outstanding	16,898,137	17,804,039
Treasury Stock, Shares	1,814,158	908,256