Earnings Per Share - Schedule of computation of basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share
Net Income													$ 47,169	$ 47,180	$ 27,545
Less: distributed earnings allocated to participating securities													(30)	(18)
Less: undistributed earnings allocated to participating securities													165	135
Net income available to common shareholders													$ 46,974	$ 47,027	$ 27,545
Weighted-average shares outstanding													8,994,022	9,007,814	9,189,876
Effect of dilutive securities stock options or awards													17,122	2,923	9,293
Denominator for diluted earnings per share													9,011,144	9,010,737	9,199,169
Basic earnings per share available to common stockholders	$ 1.41	$ 1.03	$ 1.35	$ 1.43	$ 1.53	$ 1.27	$ 1.33	$ 1.09	$ 0.76	$ 0.55	$ 0.84	$ 0.85	$ 5.22	$ 5.22	$ 3.00
Diluted earnings per share available to common stockholders	$ 1.41	$ 1.03	$ 1.34	$ 1.43	$ 1.53	$ 1.27	$ 1.32	$ 1.09	$ 0.76	$ 0.55	$ 0.84	$ 0.85	$ 5.21	$ 5.22	$ 2.99