EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Common Share
Net income	$ 307,165	$ 240,716	$ 215,707
Preferred stock dividends	0	0	(103)
Preferred stock redemption	0	0	(86)
Net income attributable to common stock	$ 307,165	$ 240,716	$ 215,518
Average common shares issued and outstanding (in shares)	59,691,541	59,523,626	59,229,495
Earnings per common share (in dollars per share)	$ 5.15	$ 4.04	$ 3.64
Diluted Earnings Per Common Share
Net income attributable to common stock	$ 307,165	$ 240,716	$ 215,518
Average common shares issued and outstanding (in shares)	59,691,541	59,523,626	59,229,495
Dilutive effect of average unvested RSUs (in shares)	875,313	1,087,328	1,290,116
Total dilutive common shares outstanding (in shares)	60,566,854	60,610,954	60,519,611
Diluted earnings per common share (in dollars per share)	$ 5.07	$ 3.97	$ 3.56
Weighted average antidilutive common stock equivalents (in shares)	4,505	9,701	69,389