Consolidated Statements Of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
INTEREST AND DIVIDEND INCOME:
Loans receivable	$ 69,613	$ 71,657	$ 139,527	$ 142,429
Mortgage-backed securities (MBS)	5,866	6,301	11,968	12,824
FHLB stock	1,714	1,831	3,540	3,802
Investment securities	1,382	1,505	2,889	2,946
Cash and cash equivalents	380	743	1,067	2,457
Total interest and dividend income	78,955	82,037	158,991	164,458
INTEREST EXPENSE:
Deposits	17,804	16,096	35,766	31,821
Borrowings	12,483	13,344	25,860	27,739
Total interest expense	30,287	29,440	61,626	59,560
NET INTEREST INCOME	48,668	52,597	97,365	104,898
PROVISION FOR CREDIT LOSSES	22,075	0	22,300	0
NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES	26,593	52,597	75,065	104,898
NON-INTEREST INCOME:
Revenue from contracts with customers			7,500	8,100
Other non-interest income	1,488	1,369	3,239	2,815
Total non-interest income	4,671	5,001	10,175	10,425
NON-INTEREST EXPENSE:
Salaries and employee benefits	13,235	12,789	26,706	25,751
Information technology and related expense	4,268	4,284	8,409	8,883
Occupancy, net	3,449	3,292	6,656	6,544
Advertising and promotional	1,359	1,390	2,769	2,150
Regulatory and outside services	1,297	1,056	2,640	2,822
Deposit and loan transaction costs	678	465	1,389	1,201
Office supplies and related expense	592	736	1,111	1,195
Federal insurance premium	0	659	0	1,187
Other non-interest expense	1,286	1,470	2,984	3,190
Total non-interest expense	26,164	26,141	52,664	52,923
INCOME BEFORE INCOME TAX EXPENSE	5,100	31,457	32,576	62,400
INCOME TAX EXPENSE	824	6,903	5,789	13,463
NET INCOME	$ 4,276	$ 24,554	$ 26,787	$ 48,937
Basic earnings per share (EPS)	$ 0.03	$ 0.18	$ 0.19	$ 0.36
Diluted EPS	$ 0.03	$ 0.18	$ 0.19	$ 0.36
Basic weighted average common shares	137,968,327	137,634,820	137,932,976	137,592,409
Diluted weighted average common shares	138,000,334	137,690,717	137,988,649	137,641,126
Deposit service fees [Member]
NON-INTEREST INCOME:
Revenue from contracts with customers	$ 2,783	$ 3,091	$ 5,845	$ 6,443
Insurance commissions [Member]
NON-INTEREST INCOME:
Revenue from contracts with customers	$ 400	$ 541	$ 1,091	$ 1,167