EARNINGS PER SHARE (EPS) (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Common shares outstanding (in shares)	56,684	47,431	56,684	47,431
Unallocated ESOP shares (in shares)	(1,961)	(2,159)	(1,961)	(2,159)
Non-vested restricted stock (in shares)	(3,822)	(3,562)	(3,822)	(3,562)
Impact of weighted average shares (in shares)	(63)	(145)	(184)	(341)
Weighted average shares outstanding - basic (in shares)	50,838	41,565	50,717	41,369
Incremental shares from stock based compensation (in shares)	2,426	2,169	2,494	2,457
Weighted average shares outstanding - diluted (in shares)	53,264	43,734	53,211	43,826