Accumulated Other Comprehensive Income (AOCI) - Components of AOCI (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, included in stockholders' equity	$ (28,095)	$ (22,404)
Tax effect	6,170	4,917
Net of tax amount	446,058	320,772	$ 283,423	$ 258,347
Net unrealized loss on securities available-for-sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, included in stockholders' equity	(28,062)	(22,366)
Net unrealized gain on securities available-for-sale securities for which a portion of an other-than-temporary impairment has been recognized in income
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, included in stockholders' equity	(1)	(1)
Unrealized gain from defined benefit pension plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
AOCI, included in stockholders' equity	(32)	(37)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net of tax amount	$ (21,925)	$ (17,487)	$ 2,882	$ 4,447