Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
INTEREST INCOME
Loans receivable	$ 900,068	$ 601,592	$ 537,660
Mortgage-backed securities	43,184	26,332	24,708
Investment securities and cash equivalents	99,703	38,435	29,242
Total Income	1,042,955	666,359	591,610
INTEREST EXPENSE
Customer accounts	237,233	43,041	42,313
Borrowings	115,488	28,729	44,188
Total interest expense	352,721	71,770	86,501
Net interest income	690,234	594,589	505,109
Provision (release) for credit losses	41,500	3,000	500
Net interest income after provision (release)	648,734	591,589	504,609
OTHER INCOME
Gain (loss) on sale of investment securities	33	99	14
Gain (loss) on termination of hedging derivatives	(867)	0	14,110
Prepayment penalty on long-term debt	0	0	(13,788)
Loan fee income	$ 3,885	$ 7,168	$ 6,899
Deposit fee income	Deposit Account [Member]	Deposit Account [Member]	Deposit Account [Member]
Deposit fee income	$ 26,050	$ 25,942	$ 24,686
Other income	23,100	33,163	28,640
Total other income	52,201	66,372	60,561
OTHER EXPENSE
Compensation and benefits	196,534	193,917	176,106
Occupancy	41,579	42,499	39,610
FDIC insurance premiums	20,025	9,531	14,368
Product delivery	20,973	19,536	18,505
Information technology	49,447	47,202	42,737
Other expense	47,477	45,890	41,133
Total other expense	376,035	358,575	332,459
Gain on real estate owned, net	176	651	427
Income before income taxes	325,076	300,037	233,138
Income tax expense	67,650	63,707	49,523
Net income	257,426	236,330	183,615
Dividends on preferred stock	14,625	14,625	10,034
Net income available to common shareholders	$ 242,801	$ 221,705	$ 173,581
PER SHARE DATA
Basic earnings per share (in dollars per share)	$ 3.72	$ 3.40	$ 2.39
Diluted earnings per share (in dollars per share)	3.72	3.39	2.39
Dividends paid on common stock per share (in dollars per share)	$ 0.99	$ 0.95	$ 0.91
Basic weighted average number of common shares outstanding (in shares)	65,192,510	65,287,650	72,529,188
Diluted weighted average number of common shares outstanding (in shares)	65,255,283	65,404,110	72,565,920