EARNINGS PER SHARE (EPS) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Common shares outstanding (in shares)	56,677	47,425	56,677	47,425
Unallocated ESOP shares (in shares)	(1,912)	(2,108)	(1,912)	(2,108)
Non-vested restricted stock (in shares)	(3,814)	(3,555)	(3,814)	(3,555)
Impact of weighted average shares (in shares)	(48)	(50)	(172)	(279)
Weighted average shares outstanding - basic (in shares)	50,903	41,712	50,779	41,483
Incremental shares from stock based compensation (in shares)	2,601	2,062	2,527	2,335
Weighted average shares outstanding - diluted (in shares)	53,504	43,774	53,306	43,818