Washington Federal (WAFD) 10-Q 31 Jan 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Dec. 31, 2023	Jan. 30, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	001-34654
Entity Registrant Name	WAFD, INC.
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-1661606
Entity Address, Address Line One	425 Pike Street
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98101
City Area Code	206
Local Phone Number	624-7930
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		64,736,916
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000936528
Current Fiscal Year End Date	--09-30
Common Stock, $1.00 par value per share
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $1.00 par value per share
Trading Symbol	WAFD
Security Exchange Name	NASDAQ
Depositary Shares, Each Representing a 1/40th Interest in a Share of 4.875% Fixed Rate Series A Non-Cumulative Perpetual Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, Each Representing a 1/40th Interest in a Share of 4.875% Fixed Rate Series A Non-Cumulative Perpetual Preferred Stock
Trading Symbol	WAFDP
Security Exchange Name	NASDAQ

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (UNAUDITED) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
ASSETS
Cash and cash equivalents	$ 1,144,774	$ 980,649
Available-for-sale securities, at fair value	2,018,445	1,995,097
Held-to-maturity securities, at amortized cost	415,079	423,586
Loans receivable, net of allowance for loan losses of $179,320 and $177,207	17,584,622	17,476,550
Interest receivable	87,022	87,003
Premises and equipment, net	237,202	237,011
Real estate owned	6,820	4,149
FHLB stock	137,940	126,820
Bank owned life insurance	244,558	242,919
Intangible assets, including goodwill of $305,125 and $304,750	311,103	310,619
Federal and state income tax assets, net	0	8,479
Other assets	452,557	581,793
Total assets	22,640,122	22,474,675
Customer accounts
Transaction deposit accounts	10,658,064	10,765,313
Time deposit accounts	5,380,723	5,305,016
Total customer accounts	16,038,787	16,070,329
Borrowings	3,875,000	3,650,000
Advance payments by borrowers for taxes and insurance	19,244	52,550
Federal and state income tax liabilities, net	1,478	0
Accrued expenses and other liabilities	253,609	275,370
Total liabilities	20,188,118	20,048,249
Commitments and contingencies (see Note I)
Shareholders’ equity
Preferred stock, $1.00 par value, 5,000,000 shares authorized; 300,000 and 300,000 shares issued; 300,000 and 300,000 shares outstanding	300,000	300,000
Common stock, $1.00 par value, 300,000,000 shares authorized; 136,679,479 and 136,466,579 shares issued; 64,254,700 and 64,736,916 shares outstanding	136,679	136,467
Additional paid-in capital	1,691,102	1,687,634
Accumulated other comprehensive income (loss), net of taxes	47,014	46,921
Treasury stock, at cost; 72,424,779 and 71,729,663 shares	(1,629,348)	(1,612,345)
Retained earnings	1,906,557	1,867,749
Total stockholders' equity	2,452,004	2,426,426
Total liabilities and shareholders' equity	$ 22,640,122	$ 22,474,675

CONSOLIDATED STATEMENTS OF FI_2

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (UNAUDITED)  (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Statement of Financial Position [Abstract]
Allowance for credit losses on loans	$ 179,320	$ 177,207
Goodwill	$ 305,125	$ 304,750
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	300,000	300,000
Preferred stock, shares outstanding (in shares)	300,000	300,000
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	136,679,479	136,466,579
Common stock, shares outstanding (in shares)	64,254,700	64,736,916
Treasury stock, shares (in shares)	72,424,779	71,729,663

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($)	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
INTEREST INCOME
Loans receivable	$ 245,792,000	$ 203,946,000
Mortgage-backed securities	11,266,000	10,613,000
Investment securities and cash equivalents	29,788,000	18,860,000
Total income	286,846,000	233,419,000
INTEREST EXPENSE
Customer accounts	96,671,000	31,646,000
Borrowings	37,938,000	18,974,000
Total interest expense	134,609,000	50,620,000
Net interest income	152,237,000	182,799,000
Provision for credit losses	0	2,500,000
Net interest income after provision (release)	152,237,000	180,299,000
OTHER INCOME
Gain (loss) on sale of investment securities	81,000	0
Gain (loss) on termination of hedging derivatives	109,000	0
Loan fee income	844,000	1,502,000
Deposit fee income	$ 6,802,000	$ 6,353,000
Revenue, Product and Service [Extensible Enumeration]	Deposit Account [Member]	Deposit Account [Member]
Other income	$ 6,331,000	$ 6,169,000
Total other income	14,167,000	14,024,000
OTHER EXPENSE
Compensation and benefits	49,841,000	49,070,000
Occupancy	9,371,000	10,102,000
FDIC insurance premiums	6,570,000	3,675,000
Product delivery	6,009,000	4,621,000
Information technology	12,866,000	12,329,000
Other expense	11,883,000	12,481,000
Total other expense	96,540,000	92,278,000
Gain (loss) on real estate owned, net	1,826,000	(112,000)
Income before income taxes	71,690,000	101,933,000
Income tax expense	13,237,000	22,424,000
Net income	58,453,000	79,509,000
Dividends on preferred stock	3,656,000	3,656,000
Net income available to common shareholders	$ 54,797,000	$ 75,853,000
PER SHARE DATA
Basic earnings per common share (in dollars per share)	$ 0.85	$ 1.16
Diluted earnings per common share (in dollars per share)	0.85	1.16
Dividends paid on common stock (in dollars per share)	$ 0.25	$ 0.24
Basic weighted average number of shares outstanding (in shares)	64,297,499	65,341,974
Diluted weighted average number of shares outstanding (in shares)	64,312,110	65,430,690

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 58,453	$ 79,509
Other comprehensive income (loss) net of tax:
Net unrealized gain (loss) during the period on available-for-sale investment securities, net of tax of $(9,294) and $1,659	31,276	(5,521)
Reclassification adjustment of net (gain) loss from sale of available-for-sale securities included in net income, net of tax of $(19) and $0	63	0
Net unrealized gain (loss) from investment securities, net of reclassification adjustment	31,339	(5,521)
Net unrealized gain (loss) during the period on borrowings cash flow hedges, net of tax of $9,281 and $1,572	(31,246)	(5,234)
Net unrealized gain (loss) in cash flow hedging instruments, net of reclassification adjustment	(31,246)	(5,234)
Other comprehensive income (loss)	93	(10,755)
Comprehensive income	$ 58,546	$ 68,754

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED)  (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Related tax expense (benefit) for net unrealized gain (loss) on available-for-sale debt securities	$ (9,294)	$ 1,659
Related tax benefit (expense) for reclassification adjustment of net (gain) loss included in net income during the period from sale of available-for-sale securities	(19)	0
Related tax expense (benefit) for net unrealized gain (loss) on borrowing cash flow hedges	$ 9,281	$ 1,572

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance, beginning of period at Sep. 30, 2022	$ 2,274,260	$ 300,000	$ 136,271	$ 1,686,975	$ 1,688,740	$ 52,481	$ (1,590,207)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	79,509				79,509
Other comprehensive income (loss)	(10,755)					(10,755)
Dividends on common stock	(15,585)				(15,585)
Dividends on preferred stock	(3,656)				(3,656)
Proceeds from stock issuances	765		25	740
Stock-based compensation expense	1,571		77	1,494
Treasury stock purchased	(1,728)						(1,728)
Balance, end of period at Dec. 31, 2022	2,324,381	300,000	136,373	1,689,209	1,749,008	41,726	(1,591,935)
Balance, beginning of period at Sep. 30, 2023	2,426,426	300,000	136,467	1,687,634	1,867,749	46,921	(1,612,345)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	58,453				58,453
Other comprehensive income (loss)	93					93
Dividends on common stock	(15,989)				(15,989)
Dividends on preferred stock	(3,656)				(3,656)
Proceeds from stock issuances	1,449		55	1,394
Stock-based compensation expense	2,293		157	2,074			62
Treasury stock purchased	(17,065)						(17,065)
Balance, end of period at Dec. 31, 2023	$ 2,452,004	$ 300,000	$ 136,679	$ 1,691,102	$ 1,906,557	$ 47,014	$ (1,629,348)

CONSOLIDATED STATEMENTS OF SH_2

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED)  (Parenthetical) - $ / shares	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Dividends paid on common stock (in dollars per share)	$ 0.25	$ 0.24
Dividends paid on preferred stock (in dollars per share)	$ 12.1875	$ 12.1875

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 58,453,000	$ 79,509,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, accretion and other, net	(22,095,000)	1,613,000
Stock-based compensation expense	2,293,000	1,571,000
Provision (release) for credit losses	0	2,500,000
Loss (gain) on sale of investment securities	(81,000)	0
Gain on settlements of bank owned life insurance	0	(821,000)
Net realized (gain) loss on sales of premises, equipment, and real estate owned	(3,571,000)	(230,000)
Decrease (increase) in accrued interest receivable	(19,000)	(11,444,000)
Decrease (increase) in federal and state income tax receivable	8,451,000	0
Decrease (increase) in cash surrender value of bank owned life insurance	(1,639,000)	(439,000)
Decrease (increase) in other assets	85,553,000	3,134,000
Increase (decrease) in federal and state income tax liabilities	1,478,000	16,920,000
Increase (decrease) in accrued expenses and other liabilities	(18,563,000)	(26,213,000)
Net cash provided by (used in) operating activities	110,260,000	66,100,000
CASH FLOWS FROM INVESTING ACTIVITIES
Origination of loans and principal repayments, net	(81,947,000)	(802,470,000)
Loans purchased	0	(77,484,000)
FHLB stock purchased	(156,375,000)	(176,000,000)
FHLB stock redeemed	145,255,000	138,000,000
Available-for-sale securities purchased	(49,380,000)	(115,909,000)
Principal payments and maturities of available-for-sale securities	64,120,000	100,340,000
Proceeds from sales of available-for-sale securities	2,624,000	0
Principal payments and maturities of held-to-maturity securities	8,438,000	9,793,000
Proceeds from sales of real estate owned	4,762,000	744,000
Purchase of strategic investments	0	(7,500,000)
Net cash received (paid) in business combinations	(750,000)	0
Proceeds from sales of premises and equipment	421,000	664,000
Premises and equipment purchased and REO improvements	(8,195,000)	(2,217,000)
Net cash provided by (used in) investing activities	(71,027,000)	(932,039,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in customer accounts	(31,542,000)	(69,535,000)
Proceeds from borrowings	6,050,000,000	4,400,000,000
Repayments of borrowings	(5,825,000,000)	(3,450,000,000)
Proceeds from stock-based awards	1,220,000	765,000
Dividends paid on common stock	(15,989,000)	(15,585,000)
Dividends paid on preferred stock	(3,656,000)	(3,656,000)
Proceeds from employee stock purchase	229,000	0
Treasury stock purchased	(17,064,000)	(1,728,000)
Increase (decrease) in advances payments by borrowers for taxes and insurance	(33,306,000)	(32,425,000)
Net cash provided by (used in) financing activities	124,892,000	827,836,000
Increase (decrease) in cash and cash equivalents	164,125,000	(38,103,000)
Cash, cash equivalents and restricted cash at beginning of period	980,649,000	683,965,000
Cash, cash equivalents and restricted cash at end of period	1,144,774,000	645,862,000
Non-cash investing activities
Real estate acquired through foreclosure	0	95,000
Non-cash financing activities
Preferred stock dividend payable	3,656,000	3,656,000
Cash paid (received) during the period for
Interest	131,204,000	48,195,000
Income tax	$ (738,000)	$ 1,016,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Company and Nature of Operations - Washington Federal Bank, a federally-insured Washington state chartered commercial bank dba WaFd Bank (the “Bank” or “WaFd Bank”), was founded on April 24, 1917 in Ballard, Washington and is engaged primarily in providing lending, depository, insurance and other banking services to consumers, mid-sized to large businesses, and owners and developers of commercial real estate. Washington Federal, Inc., a Washington corporation, was formed as the Bank’s holding company in November, 1994. On September 27, 2023, Articles of Amendment were filed with the Washington Secretary of State to change the name of Washington Federal, Inc. to WaFd, Inc. This change was effective on September 29, 2023. As used throughout this document, the terms “WaFd” or the “Company” or “we” or “us” and “our” refer to WaFd, Inc. and its consolidated subsidiaries, and the term “Bank” refers to the operating subsidiary, Washington Federal Bank dba WaFd Bank. The Company is headquartered in Seattle, Washington. The Bank conducts its activities through a network of 198 bank branches located in Washington, Oregon, Idaho, Utah, Arizona, Nevada, New Mexico and Texas. Basis of Presentation - The Company has prepared the consolidated unaudited interim financial statements included in this report. All intercompany transactions and accounts have been eliminated in consolidation. The preparation of financial statements, in conformity with accounting principles generally accepted in the United States of America (“GAAP”), requires management to make estimates and assumptions that affect amounts reported in the financial statements. Actual results could differ from these estimates. In the opinion of management, all adjustments (consisting only of normal recurring adjustments) necessary for a fair presentation are reflected in the interim financial statements. The information included in this Form 10-Q should be read in conjunction with the financial statements and related notes contained in the Company's 2023 Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on November 17, 2023 ("2023 Annual Financial Statements"). Interim results are not necessarily indicative of results for a full year. Summary of Significant Accounting Policies - The significant accounting policies used in preparation of the Company's consolidated financial statements are disclosed in its 2023 Annual Financial Statements. There have not been any significant changes in the Company's significant accounting policies compared to those contained in its 2023 Annual Financial Statements. Preferred Stock - On February 8, 2021, in connection with an underwritten public offering, the Company issued 300,000 shares of 4.875% Noncumulative Perpetual Series A Preferred Stock (“Series A Preferred Stock”). Net proceeds, after underwriting discounts and expenses, were $293,325,000. The public offering consisted of the issuance and sale of 12,000,000 depositary shares, each representing a 1/40 th interest in a share of the Series A Preferred Stock, at a public offering price of $25.00 per depositary share. Holders of the depositary shares are entitled to all proportional rights and preferences of the Series A Preferred Stock (including dividend, voting, redemption and liquidation rights). The depositary shares are traded on the NASDAQ Global Select Market under the symbol "WAFDP." The Series A Preferred Stock is redeemable at the option of the Company, subject to all applicable regulatory approvals, on or after April 15, 2026. Restricted Cash Balances - Based on the level of vault cash on hand, the Company was not required to maintain cash reserve balances with the Federal Reserve Bank as of December 31, 2023. As of December 31, 2023 and September 30, 2023, the Company held counterparty cash collateral of $229,100,000 and $326,750,000, respectively, related to derivative contracts. Equity Securities - The Company records equity securities within Other assets in its Consolidated Statements of Financial Condition. These equity investments are accounted for under different methods. • Low-income housing tax credit investments are accounted for under the proportional amortization method. • For equity investments where the Company has significant influence, the Company applies the equity method of accounting, which adjusts the carrying value of the investment to recognize a proportionate share of the financial results of the investment entity, regardless of whether any distribution is made. Any adjustments to the fair value of these investments are recorded in Other income in the Consolidated Statements of Operations. • For investments in certain nonmarketable equity securities investments where the equity method of accounting is not applicable, the Company applies the fair value method. Any adjustments to the fair value of these investments are recorded in Other income in the Consolidated Statements of Operations. Fair value is determined by reference to readily determinable market values, if applicable. As these investments do not have readily determinable fair values, they are generally accounted for at cost minus impairment, if any, plus or minus changes resulting from observable transactions involving the same or similar investments from the same issuer. This practice is referred to as the measurement alternative. • Equity investments in qualified real estate funds can use the NAV expedient for fair value measurement. Under this method, the net asset value (NAV) is determined by the fund as fair value for the investment. At December 31, 2023, equity investments held by the Company and recorded at NAV had a carrying amount of $36,708,000 and a remaining unfunded commitment of $5,578,000. These NAV based investments cannot be transferred without consent and we do not have redemption rights. Equity investments measured at NAV are not classified in the fair value hierarchy. Allowance for Credit Losses (Loans Receivable) - The Company maintains an allowance for credit losses (“ACL”) for the expected credit losses of the loan portfolio as well as unfunded loan commitments. The amount of ACL is based on ongoing, quarterly assessments by management. The current expected credit loss methodology (“CECL”) requires an estimate of the credit losses expected over the life of an exposure (or pool of exposures). The ACL consists of the allowance for loan losses and the reserve for unfunded commitments. The estimate of expected credit losses under the CECL methodology is based on relevant information about past events, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amounts. Historical loss experience is generally the starting point for estimating expected credit losses. We then consider whether the historical loss experience should be adjusted for asset-specific risk characteristics or current conditions at the reporting date that did not exist over the period that historical experience was based for each loan type. Finally, we consider forecasts about future economic conditions or changes in collateral values that are reasonable and supportable. Portfolio segment is defined as the level at which an entity develops and documents a systematic methodology to determine its ACL. The Company has designated two loan portfolio segments, commercial loans and consumer loans. These loan portfolio segments are further disaggregated into classes, which represent loans of similar type, risk characteristics, and methods for monitoring and assessing credit risk. The commercial loan portfolio segment is disaggregated into five classes: multi-family, commercial real estate, commercial and industrial, construction, and land acquisition and development. The risk of loss for the commercial loan portfolio segment is generally most indicated by the credit risk rating assigned to each borrower. Commercial loan risk ratings are determined by experienced senior credit officers based on specific facts and circumstances and are subject to periodic review by an independent internal team of credit specialists. The consumer loan portfolio segment is disaggregated into five classes: single-family-residential mortgage, custom construction, consumer lot loans, home equity lines of credit, and other consumer. The risk of loss for the consumer loan portfolio segment is generally most indicated by delinquency status and general economic factors. Each commercial and consumer loan portfolio class may also be further segmented based on risk characteristics. For the majority of the Company's loan portfolio classes, the historical loss experience is determined using a cohort methodology. This method pools loans into groups (“cohorts”) sharing similar risk characteristics and tracks each cohort’s net charge-offs over the lives of the loans to calculate a historical loss rate. The historical loss rates for each cohort are then averaged to calculate an overall historical loss rate which is applied to the current loan balance to arrive at the quantitative baseline portion of the allowance for credit losses for the respective loan portfolio class. For certain loan portfolio classes, the Company determined there was not sufficient historical loss information to calculate a meaningful historical loss rate using the cohort methodology. For any such loan portfolio class, the weighted-average remaining maturity (“WARM”) methodology is being utilized until sufficient historical loss data is obtained. The WARM method multiplies an average annual loss rate by the expected remaining life of the loan pool to arrive at the quantitative baseline portion of the allowance for credit losses for the respective loan portfolio class. The Company also considers qualitative adjustments to the historical loss rate for each loan portfolio class. The qualitative adjustments for each loan class consider the conditions over the period from which historical loss experience was based and are split into two components: 1) asset or class specific risk characteristics or current conditions at the reporting date related to portfolio credit quality, remaining payments, volume and nature, credit culture and management, business environment or other management factors and 2) reasonable and supportable forecast of future economic conditions and collateral values. The Company performs a quarterly asset quality review which includes a review of forecasted gross charge-offs and recoveries, nonperforming assets, criticized loans, risk rating migration, delinquencies, etc. The asset quality review is performed by management and the results are used to consider a qualitative overlay to the quantitative baseline. The second qualitative adjustment noted above, economic conditions and collateral values, encompasses a one-year reasonable and supportable forecast period. The overlay adjustment for the reasonable and supportable forecast assumes an immediate reversion after the one-year forecast period to historical loss rates for the remaining life of the respective loan pool. The Company may establish a specific reserve for individually evaluated loans that do not share similar risk characteristics with the loans included in each respective loan pool if management deems it appropriate. If this occurs, these individually evaluated loans are removed from their respective pools and typically represent collateral dependent loans but may also include other non-performing loans. Allowance for Credit Losses (Held-to-Maturity Debt Securities) - For held-to-maturity (“HTM”) debt securities, the Company is required to utilize a CECL methodology to estimate expected credit losses. Substantially all of the Company’s HTM debt securities are issued by U.S. government agencies or U.S. government-sponsored enterprises. These securities carry the explicit and/or implicit guarantee of the U.S. government and have a long history of zero credit loss. See Note F "Fair Value Measurements" for more information about HTM debt securities. Allowance for Credit Losses (Available-for-Sale Debt Securities) - The impairment model for available-for-sale (“AFS”) debt securities differs from the CECL methodology applied for HTM debt securities because AFS debt securities are measured at fair value rather than amortized cost. For AFS debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell, the security before recovery of its amortized cost basis. If either criteria is met, the security’s amortized cost basis is written down to fair value through income. For AFS debt securities where neither of the criteria are met, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the credit rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited to the amount that the fair value is less than the amortized cost basis. Any remaining discount that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. Changes in the allowance for credit losses are recorded as a provision for (or recapture of) credit losses. Losses are charged against the allowance when management believes the uncollectibility of an AFS security is confirmed or when either of the criteria regarding intent or requirement to sell is met. See Note F "Fair Value Measurements" for more information about AFS debt securities. Accrued Interest Receivable - The Company made the following elections regarding accrued interest receivable (“AIR”): • Presenting accrued interest receivable balances separately from their underlying instruments within the consolidated statements of financial condition. • Excluding accrued interest receivable that is included in the amortized cost of financing receivables from related disclosure requirements. • Continuing the Company's policy to write off accrued interest receivable by reversing interest income in cases where the Company does not reasonably expect to receive payment. • Not measuring an allowance for credit losses for accrued interest receivable due to the Company’s policy of writing off uncollectible accrued interest receivable balances in a timely manner, as described above. Non-Accrual Loans - Loans are placed on non-accrual status when, in the judgment of management, the probability of collection of interest is deemed to be insufficient to warrant further accrual. When a loan is placed on non-accrual status, previously accrued but unpaid interest is deducted from interest income. The Bank does not accrue interest on loans 90 days or more past due. If payment is made on a loan so that the loan becomes less than 90 days past due, and the Bank expects full collection of principal and interest, the loan is returned to full accrual status. Any interest ultimately collected is credited to income in the period of recovery. A loan is charged-off when the loss is estimable and it is confirmed that the borrower is not expected to be able to meet contractual obligations. If a consumer loan is on non-accrual status before being modified, it will stay on non-accrual status following restructuring until it has been performing for at least six months, at which point it may be moved to accrual status. For commercial loans, six consecutive payments on newly restructured loan terms are required prior to returning the loan to accrual status. In some instances, after the required six consecutive payments are made, management will conclude that collection of the entire principal and interest due is still in doubt. In those instances, the loan will remain on non-accrual status. Collateral-Dependent Loans - A financial asset is considered collateral-dependent when the debtor is experiencing financial difficulty and repayment is expected to be provided substantially through the sale or operation of the collateral. For all classes of loans and leases deemed collateral-dependent, the Company elected the practical expedient to estimate expected credit losses based on the collateral’s fair value less cost to sell. In most cases, the Company records a partial charge-off to reduce the loan’s carrying value to the collateral’s fair value less cost to sell. Substantially all of the collateral consists of various types of real estate including residential properties; commercial properties such as retail centers, office buildings, and lodging; agriculture land; and vacant land. Off-balance-sheet credit exposures - The only material off-balance-sheet credit exposures are unfunded loan commitments, which had a combined balance of $3,180,001,000 and $3,625,333,000 at December 31, 2023 and September 30, 2023, respectively. The reserve for unfunded commitments is recognized as a liability (other liabilities in the consolidated statements of financial condition), with adjustments to the reserve recognized through provision for credit losses in the consolidated statements of income. The reserve for unfunded commitments represents the expected lifetime credit losses on off-balance sheet obligations such as commitments to extend credit and standby letters of credit. However, a liability is not recognized for commitments that are unconditionally cancellable by the Company. The reserve for unfunded commitments is determined by estimating future draws, including the effects of risk mitigation actions, and applying the expected loss rates on those draws. Loss rates are estimated by utilizing the same loss rates calculated for the allowance for credit losses related to the respective loan portfolio class. See Note I “Commitments and Contingencies” for more information. Subsequent events

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Dec. 31, 2023
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements In March 2023, the FASB issued ASU 2023-02, Investments - Equity Method and Joint Ventures (Topic 323) . The amendments in this ASU expand the population of tax credit investments for which an investor may elect to apply the proportional amortization method ("PAM") and require certain disclosures for tax credit investments. For public companies amendments in this ASU are effective for fiscal years beginning after December 15, 2023, with early adoption permitted. The Company has utilized PAM for low income housing tax credit investments. The Company does not expect this ASU to have a material effect on our consolidated financial statements. In October 2023, the FASB issued ASU 2023-6 Disclosure Improvements: Codification Amendments In Response to the SEC's Disclosure Update and Simplification Initiative to clarify or improve disclosure and presentation requirements on a variety of topics and align the requirements in the FASB accounting standard codification with the Securities and Exchange Commission regulations. The amendments will be effective for the Company only if the SEC removes the related disclosure requirement from its existing regulations no later than June 30, 2027. If the SEC timely removes such a related requirement from its existing regulations, the corresponding amendments within the ASU will become effective for the Company on the same date with early adoption permitted. The Company does not expect the amendments in this update to have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures (Topic 280) to improve reportable segment disclosure requirements through enhanced disclosures about significant segment expenses. For public companies amendments in this ASU are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 with early adoption permitted. The Company does not expect this ASU to have a material effect on our consolidated financial statements. In December 2023, the FASB issued ASU 2023-09 , Income Tax - Improvements to Income Tax Disclosures (Topic 740) which requires reporting companies to break out their income tax expense and tax rate reconciliation in more detail. For public

Dividends and Share Repurchases

Dividends and Share Repurchases	3 Months Ended
	Dec. 31, 2023
Stockholders' Equity Note [Abstract]
Dividends and Share Repurchases	Dividends and Share Repurchases On December 8, 2023, the Company paid a regular dividend on common stock of $0.25 per share, which represented the 163 rd consecutive quarterly cash dividend. Dividends per share were $0.25 and $0.24 for the quarters ended December 31, 2023 and 2022, respectively. For the three months ended December 31, 2023, the Company repurchased 697,893 shares at an average price of $24.45. As of December 31, 2023, there are 1,861,290 remaining shares authorized to be repurchased under the current Board approved share repurchase program.

Loans Receivable

Loans Receivable	3 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Loans Receivable	Loans Receivable For a detailed discussion of loans and credit quality, including accounting policies and the CECL methodology used to estimate the allowance for credit losses, see Note A "Summary of Significant Accounting Policies" above. The Company's loans held for investment are divided into two portfolio segments, commercial loans and consumer loans, with each of those segments further split into loan classes for purposes of estimating the allowance for credit losses. The following table is a summary of loans receivable by loan portfolio segment and class. December 31, 2023 September 30, 2023 Gross loans by category (In thousands) (In thousands) Commercial loans Multi-family $ 3,054,426 15.8 % $ 2,907,086 14.8 % Commercial real estate 3,351,113 17.3 3,344,959 17.0 Commercial & industrial 2,371,393 12.3 2,321,717 11.8 Construction 2,868,207 14.8 3,318,994 16.9 Land - acquisition & development 190,732 1.0 201,538 1.0 Total commercial loans 11,835,871 61.2 12,094,294 61.6 Consumer loans Single-family residential 6,535,073 33.8 6,451,270 32.8 Construction - custom 543,748 2.8 672,643 3.4 Land - consumer lot loans 119,735 0.6 125,723 0.6 HELOC 243,742 1.2 234,410 1.2 Consumer 74,884 0.4 70,164 0.4 Total consumer loans 7,517,182 38.8 7,554,210 38.4 Total gross loans 19,353,053 100 % 19,648,504 100 % Less: Allowance for credit losses on loans 179,320 177,207 Loans in process 1,516,522 1,895,940 Net deferred fees, costs and discounts 72,589 98,807 Total loan contra accounts 1,768,431 2,171,954 Net loans $ 17,584,622 $ 17,476,550 The Company elected to exclude accrued interest receivable from the amortized cost basis of loans for disclosure purposes and from the calculations of estimated credit losses. As of December 31, 2023, and September 30, 2023, AIR for loans totaled $77,760,000 and $77,349,000, respectively, and is included in the Interest receivable line item balance on the Company’s consolidated statements of financial condition. Loans in the amount of $10,493,301,000 and $8,941,201,000 at December 31, 2023 and September 30, 2023, respectively, were pledged to secure borrowings from the Federal Home Loan Bank ("FHLB") as part of the Company's liquidity management strategy. The FHLB does not have the right to sell or re-pledge these loans. The following table sets forth the amortized cost basis of non-accrual loans and loans 90 days or more past due and accruing. December 31, 2023 September 30, 2023 (In thousands, except ratio data) Non-accrual Non-accrual with no ACL 90 days or more past due and accruing Non-accrual Non-accrual with no ACL 90 days or more past due and accruing Commercial loans Multi-family $ 132 $ — $ — $ 5,127 $ — $ — Commercial real estate 24,283 — — 23,435 — — Commercial & industrial 4,437 — — 6,082 — — Construction — — — — — — Land - acquisition & development — — — — — — Total commercial loans 28,852 — — 34,644 — — Consumer loans Single-family residential 15,396 — — 14,918 — — Construction - custom 88 — — 88 — — Land - consumer lot loans 57 — — 9 — — HELOC 603 — — 736 — — Consumer 262 — — 27 — — Total consumer loans 16,406 — — 15,778 — — Total non-accrual loans $ 45,258 $ — $ — $ 50,422 $ — $ — % of total loans 0.25 % 0.29 % The Company recognized interest income on non-accrual loans of approximately $511,000 in the three months ended December 31, 2023 as a result of the collection of past due amounts. If these loans had been on accrual status and performed according to their original contract terms, the Company would have recognized interest income of approximately $625,000 for the three months ended December 31, 2023. Interest cash flows collected on non-accrual loans vary from period to period as those loans are brought current or are paid off. The following tables provide details regarding loan delinquencies by loan portfolio and class. December 31, 2023 Days Delinquent Based on $ Amount of Loans % based Type of Loan Loans Receivable (Amortized Cost) Current 30 60 90 Total Delinquent (In thousands, except ratio data) Commercial Loans Multi-family $ 3,022,457 $ 3,022,325 $ — $ — $ 132 $ 132 — % Commercial real estate 3,332,293 3,307,076 934 — 24,283 25,217 0.76 Commercial & industrial 2,364,982 2,357,841 2,686 20 4,435 7,141 0.30 Construction 1,695,506 1,695,506 — — — — Land - acquisition & development 148,711 148,711 — — — — — Total commercial loans 10,563,949 10,531,459 3,620 20 28,850 32,490 0.31 Consumer Loans Single-family residential 6,495,449 6,473,306 6,131 4,065 11,947 22,143 0.34 Construction - custom 263,638 262,791 760 — 87 847 0.32 Land - consumer lot loans 118,917 118,524 336 — 57 393 0.33 HELOC 247,145 245,477 1,117 — 551 1,668 0.67 Consumer 74,844 74,328 208 47 261 516 0.69 Total consumer loans 7,199,993 7,174,426 8,552 4,112 12,903 25,567 0.36 Total Loans $ 17,763,942 $ 17,705,885 $ 12,172 $ 4,132 $ 41,753 $ 58,057 0.33 % Delinquency % 99.67% 0.07% 0.01% 0.24% 0.33% September 30, 2023 Days Delinquent Based on $ Amount of Loans % based Type of Loan Loans Receivable (Amortized Cost) Current 30 60 90 Total Delinquent (In thousands, except ratio data) Commercial Loans Multi-family $ 2,886,594 $ 2,886,462 $ — $ — $ 132 $ 132 — % Commercial real estate 3,310,101 3,285,673 848 145 23,435 24,428 0.74 Commercial & industrial 2,315,318 2,307,020 30 2,186 6,082 8,298 0.36 Construction 1,838,936 1,838,936 — — — — — Land - acquisition & development 156,661 156,661 — — — — — Total commercial loans 10,507,610 10,474,752 878 2,331 29,649 32,858 0.31 Consumer Loans Single-family residential 6,388,990 6,365,065 6,441 6,068 11,416 23,925 0.37 Construction - custom 324,451 320,987 760 2,617 87 3,464 1.07 Land - consumer lot loans 124,842 124,231 358 245 8 611 0.49 HELOC 237,754 235,708 1,050 314 682 2,046 0.86 Consumer 70,110 69,699 228 107 76 411 0.59 Total consumer loans 7,146,147 7,115,690 8,837 9,351 12,269 30,457 0.43 Total Loans $ 17,653,757 $ 17,590,442 $ 9,715 $ 11,682 $ 41,918 $ 63,315 0.36 % Delinquency % 99.64% 0.06% 0.07% 0.24% 0.36% On October 1, 2023, the Company adopted ASU 2022-02, Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures, which eliminated the accounting guidance on troubled debt restructurings ("TDRs") and requires enhanced disclosures for loan modifications to borrowers experiencing financial difficulty. This guidance was applied on a prospective basis. These modified balances are included in their segment cohort based on loan type for the purpose of calculating historical loss rates as described in Note A. Loans may be modified as the result of borrowers experiencing financial difficulty needing relief from the contractual terms of their loan. Most loan modifications to borrowers experiencing financial difficulty are accruing and performing loans where the borrower has approached the Company about modification due to temporary financial difficulties. Each request for modification is individually evaluated for merit and likelihood of success. Often a term extension is needed in the short term in order to evaluate the need for further corrective action. Payment delays and interest-only payments may also be approved during the modification period. Principal forgiveness is not an available option for restructured loans. For commercial loans, modifications could be any of the above-listed modification types available or a mix thereof. Modifications to extend the term, lower the payment amount or delay payment are made for the purposes of providing borrowers additional time to return to compliance with the terms of their loans. Renewals of commercial lines to borrowers experiencing financial difficulty are included within the disclosures below though many of these are made in the normal course of business. For consumer loans, modifications typically consist of minor payment delays or deferrals and may include a modification of the existing contractual rate or extension of the maturity date, or both, when it is determined the borrowers are likely to successfully maintain compliance with these modified loan terms. The following table presents the amortized basis of loans that were modified to borrowers experiencing financial difficulty during the period by loan class and modification type. All such modifications during the quarter were term extensions. Three Months Ended December 31, 2023 Loan Class Term Extension % of Total Loan Class Balance Wtd. Avg. ( in thousands) (in months) Commercial real estate $ 143 — % 20 Commercial & industrial 7,814 0.33 4 Construction 346 0.02 4 Total commercial loans 8,303 0.09 Total Loans $ 8,303 0.05 % The Company closely monitors the performance of the loans that are modified to borrowers experiencing financial difficulty to understand the effectiveness of modification efforts. Only one loan modified in the three months ended December 31, 2023 was 31 days past due, all others were current. This loan had an amortized cost of $1,659,000 at December 31, 2023 and belonged to the commercial & industrial class. None of the loans above have defaulted after modification. The Company evaluates the credit quality of its loans based on regulatory risk ratings and also consider other factors. Based on this evaluation, the loans are assigned a grade and classified as follows: • Pass – the credit does not meet one of the definitions below. • Special mention – A special mention credit is considered to be currently protected from loss but is potentially weak. No loss of principal or interest is foreseen; however, proper supervision and management attention is required to deter further deterioration in the credit. Assets in this category constitute some undue and unwarranted credit risk but not to the point of justifying a risk rating of substandard. The credit risk may be relatively minor yet constitutes an unwarranted risk in light of the circumstances surrounding a specific asset. • Substandard – A substandard credit is an unacceptable credit. Additionally, repayment in the normal course is in jeopardy due to the existence of one or more well defined weaknesses. In these situations, loss of principal is likely if the weakness is not corrected. A substandard asset is inadequately protected by the current sound worth and paying capacity of the borrower or of the collateral pledged, if any. Assets so classified will have a well-defined weakness or weaknesses that jeopardize the collection or liquidation of the debt. Loss potential, while existing in the aggregate amount of substandard assets, does not have to exist in individual assets risk rated substandard. • Doubtful – A credit classified doubtful has all the weaknesses inherent in one classified substandard with the added characteristic that the weakness makes collection or liquidation in full, on the basis of currently existing facts, conditions and values, highly questionable and improbable. The probability of loss is high, but because of certain important and reasonably specific pending factors that may work to the advantage and strengthening of the asset, its classification as an estimated loss is deferred until its more exact status may be determined. Pending factors include proposed merger, acquisition, or liquidation procedures, capital injection, perfecting liens on additional collateral, and refinancing plans. • Loss – Credits classified loss are considered uncollectible and of such little value that their continuance as a bankable asset is not warranted. This classification does not mean that the asset has absolutely no recovery or salvage value, but rather it is not practical or desirable to defer writing off this asset even though partial recovery may be affected in the future. Losses should be taken in the period in which they are identified as uncollectible. Partial charge-off versus full charge-off may be taken if the collateral offers some identifiable protection. The following tables present by primary credit quality indicator, loan class, and year of origination, the amortized cost basis of loans receivable as of December 31, 2023 and September 30, 2023. There were no commercial loans classified as Doubtful or Loss as of either date. December 31, 2023 Term Loans Amortized Cost Basis by Origination Year YTD 2024 2023 2022 2021 2020 Prior to 2020 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 10,416 $ 135,720 $ 778,628 $ 955,583 $ 462,169 $ 521,665 $ 35,552 $ 13,959 $ 2,913,692 Special Mention — — 90,668 — — — — — 90,668 Substandard — — 5,690 2,302 2,416 7,689 — — 18,097 Total $ 10,416 $ 135,720 $ 874,986 $ 957,885 $ 464,585 $ 529,354 $ 35,552 $ 13,959 $ 3,022,457 Commercial real estate Pass $ 61,720 $ 204,566 $ 979,199 $ 750,603 $ 444,855 $ 777,833 $ 2,317 $ — $ 3,221,093 Special Mention — — — 784 — — — — 784 Substandard — 499 12,475 2,260 29,908 65,274 — — 110,416 Total $ 61,720 $ 205,065 $ 991,674 $ 753,647 $ 474,763 $ 843,107 $ 2,317 $ — $ 3,332,293 Commercial & industrial Pass $ 13,685 $ 160,759 $ 284,699 $ 310,840 $ 112,799 $ 187,813 $ 1,154,212 $ 55 $ 2,224,862 Special Mention — — — — — — 2,850 — 2,850 Substandard — — 10,457 5,346 2,784 49,992 68,690 1 137,270 Total $ 13,685 $ 160,759 $ 295,156 $ 316,186 $ 115,583 $ 237,805 $ 1,225,752 $ 56 $ 2,364,982 Gross Charge-offs — — — — — 31 — 31 62 Construction Pass $ 16,959 $ 321,724 $ 761,021 $ 396,547 $ 49,865 $ 49,310 $ 79,723 $ — $ 1,675,149 Substandard 396 3,218 3,703 13,040 — — — — 20,357 Total $ 17,355 $ 324,942 $ 764,724 $ 409,587 $ 49,865 $ 49,310 $ 79,723 $ — $ 1,695,506 Land - acquisition & development Pass $ 9,598 $ 18,096 $ 60,988 $ 32,782 $ 6,251 $ 18,258 $ 2,600 $ — $ 148,573 Substandard — — 138 — — — — — 138 Total $ 9,598 $ 18,096 $ 61,126 $ 32,782 $ 6,251 $ 18,258 $ 2,600 $ — $ 148,711 Gross Charge-offs — — — — — 18 — — 18 Total commercial loans Pass $ 112,378 $ 840,865 $ 2,864,535 $ 2,446,355 $ 1,075,939 $ 1,554,879 $ 1,274,404 $ 14,014 $ 10,183,369 Special Mention — — 90,668 784 — — 2,850 — 94,302 Substandard 396 3,717 32,463 22,948 35,108 122,955 68,690 1 286,278 Total $ 112,774 $ 844,582 $ 2,987,666 $ 2,470,087 $ 1,111,047 $ 1,677,834 $ 1,345,944 $ 14,015 $ 10,563,949 Gross Charge-offs $ — $ — $ — $ — $ — $ 49 $ — $ 31 $ 80 December 31, 2023 Term Loans Amortized Cost Basis by Origination Year YTD 2024 2023 2022 2021 2020 Prior to 2020 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 50,755 $ 493,002 $ 1,584,370 $ 1,703,961 $ 715,431 $ 1,925,787 $ — $ — $ 6,473,306 30 days past due — 820 337 1,470 746 2,758 — — 6,131 60 days past due — — 863 1,335 — 1,867 — — 4,065 90+ days past due — 996 469 675 682 9,125 — — 11,947 Total $ 50,755 $ 494,818 $ 1,586,039 $ 1,707,441 $ 716,859 $ 1,939,537 $ — $ — $ 6,495,449 Construction - custom Current $ 1,331 $ 127,150 $ 131,617 $ 1,963 $ 372 $ 358 $ — $ — $ 262,791 30 days past due — — 760 — — — — — 760 90+ days past due — — 87 — — — — — 87 Total $ 1,331 $ 127,150 $ 132,464 $ 1,963 $ 372 $ 358 $ — $ — $ 263,638 Land - consumer lot loans Current $ 3,804 $ 18,850 $ 39,120 $ 29,413 $ 11,342 $ 15,995 $ — $ — $ 118,524 30 days past due — — — 336 — — — — 336 90+ days past due — — — 57 — — — — 57 Total $ 3,804 $ 18,850 $ 39,120 $ 29,806 $ 11,342 $ 15,995 $ — $ — $ 118,917 HELOC Current $ — $ — $ — $ — $ — $ 4,797 $ 240,274 $ 406 $ 245,477 30 days past due — — — — — 531 586 — 1,117 90+ days past due — — — — — 8 543 — 551 Total $ — $ — $ — $ — $ — $ 5,336 $ 241,403 $ 406 $ 247,145 Consumer Current $ 29 $ 139 $ 122 $ 9,648 $ 8,005 $ 21,864 $ 34,521 $ — $ 74,328 30 days past due — — — — — 145 63 — 208 60 days past due — — — — — 4 43 — 47 90+ days past due — — — — — 137 124 — 261 Total $ 29 $ 139 $ 122 $ 9,648 $ 8,005 $ 22,150 $ 34,751 $ — $ 74,844 Gross Charge-offs — — — — — 116 97 — 213 Total consumer loans Current $ 55,919 $ 639,141 $ 1,755,229 $ 1,744,985 $ 735,150 $ 1,968,801 $ 274,795 $ 406 $ 7,174,426 30 days past due — 820 1,097 1,806 746 3,434 649 — 8,552 60 days past due — — 863 1,335 — 1,871 43 — 4,112 90+ days past due — 996 556 732 682 9,270 667 — 12,903 Total $ 55,919 $ 640,957 $ 1,757,745 $ 1,748,858 $ 736,578 $ 1,983,376 $ 276,154 $ 406 $ 7,199,993 Gross Charge-offs $ — $ — $ — $ — $ — $ 116 $ 97 $ — $ 213 September 30, 2023 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior to 2019 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 135,859 $ 658,126 $ 850,998 $ 541,655 $ 135,965 $ 400,412 $ 49,523 $ — $ 2,772,538 Special Mention — 90,428 — — — — — — 90,428 Substandard — 5,711 2,309 2,422 7,583 5,603 — — 23,628 Total $ 135,859 $ 754,265 $ 853,307 $ 544,077 $ 143,548 $ 406,015 $ 49,523 $ — $ 2,886,594 Commercial real estate Pass $ 221,057 $ 912,776 $ 735,069 $ 476,941 $ 262,945 $ 596,459 $ 2,349 $ — $ 3,207,596 Special Mention — — 788 — 4,059 — — — 4,847 Substandard 499 5,361 3,810 24,538 27,916 35,534 — — 97,658 Total $ 221,556 $ 918,137 $ 739,667 $ 501,479 $ 294,920 $ 631,993 $ 2,349 $ — $ 3,310,101 Commercial & industrial Pass $ 155,411 $ 258,798 $ 316,713 $ 117,089 $ 24,246 $ 175,042 $ 1,089,896 $ 27,681 $ 2,164,876 Special Mention — — — — 2,940 — 3,707 — 6,647 Substandard — 5,532 8,537 2,783 3,819 46,297 69,948 6,879 143,795 Total $ 155,411 $ 264,330 $ 325,250 $ 119,872 $ 31,005 $ 221,339 $ 1,163,551 $ 34,560 $ 2,315,318 Construction Pass $ 235,150 $ 833,577 $ 559,850 $ 68,105 $ 46,390 $ 373 $ 74,821 $ — $ 1,818,266 Substandard 2,901 5,119 12,650 — — — — — 20,670 Total $ 238,051 $ 838,696 $ 572,500 $ 68,105 $ 46,390 $ 373 $ 74,821 $ — $ 1,838,936 Land - acquisition & development Pass $ 20,593 $ 69,414 $ 39,276 $ 6,280 $ 351 $ 17,876 $ 2,600 $ — $ 156,390 Substandard — 271 — — — — — — 271 Total $ 20,593 $ 69,685 $ 39,276 $ 6,280 $ 351 $ 17,876 $ 2,600 $ — $ 156,661 Total commercial loans Pass $ 768,070 $ 2,732,691 $ 2,501,906 $ 1,210,070 $ 469,897 $ 1,190,162 $ 1,219,189 $ 27,681 $ 10,119,666 Special Mention — 90,428 788 — 6,999 — 3,707 — 101,922 Substandard 3,400 21,994 27,306 29,743 39,318 87,434 69,948 6,879 286,022 Total $ 771,470 $ 2,845,113 $ 2,530,000 $ 1,239,813 $ 516,214 $ 1,277,596 $ 1,292,844 $ 34,560 $ 10,507,610 September 30, 2023 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior to 2019 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 513,007 $ 1,478,479 $ 1,719,163 $ 718,250 $ 295,836 $ 1,640,330 $ — $ — $ 6,365,065 30 days past due 822 115 859 392 221 4,032 — — 6,441 60 days past due — 1,526 1,420 1,325 — 1,797 — — 6,068 90+ days past due — 1,470 666 1,408 — 7,872 — — 11,416 Total $ 513,829 $ 1,481,590 $ 1,722,108 $ 721,375 $ 296,057 $ 1,654,031 $ — $ — $ 6,388,990 Construction - custom Current $ 92,081 $ 218,988 $ 8,838 $ 243 $ 358 $ 479 $ — $ — $ 320,987 30 days past due — 760 — — — — — — 760 60 days past due — — — 2,617 — — — — 2,617 90+ days past due — 87 — — — — — — 87 Total $ 92,081 $ 219,835 $ 8,838 $ 2,860 $ 358 $ 479 $ — $ — $ 324,451 Land - consumer lot loans Current $ 19,128 $ 41,658 $ 35,048 $ 11,517 $ 4,166 $ 12,714 $ — $ — $ 124,231 30 days past due — — 358 — — — — — 358 60 days past due — — 245 — — — — — 245 90+ days past due — — — — — 8 — — 8 Total $ 19,128 $ 41,658 $ 35,651 $ 11,517 $ 4,166 $ 12,722 $ — $ — $ 124,842 HELOC Current $ — $ — $ — $ — $ — $ 3,733 $ 230,338 $ 1,637 $ 235,708 30 days past due — — — — — 44 1,006 — 1,050 60 days past due — — — — — 314 — — 314 90+ days past due — — — — — — 682 — 682 Total $ — $ — $ — $ — $ — $ 4,091 $ 232,026 $ 1,637 $ 237,754 Consumer Current $ 662 $ 121 $ 9,748 $ 8,006 $ 16 $ 23,201 $ 27,945 $ — $ 69,699 30 days past due — — — — — 225 3 — 228 60 days past due — — — — — 106 1 — 107 90+ days past due — — — — 29 46 — 1 76 Total $ 662 $ 121 $ 9,748 $ 8,006 $ 45 $ 23,578 $ 27,949 $ 1 $ 70,110 Total consumer loans Current $ 624,878 $ 1,739,246 $ 1,772,797 $ 738,016 $ 300,376 $ 1,680,457 $ 258,283 $ 1,637 $ 7,115,690 30 days past due 822 875 1,217 392 221 4,301 1,009 — 8,837 60 days past due — 1,526 1,665 3,942 — 2,217 1 — 9,351 90+ days past due — 1,557 666 1,408 29 7,926 682 1 12,269 Total $ 625,700 $ 1,743,204 $ 1,776,345 $ 743,758 $ 300,626 $ 1,694,901 $ 259,975 $ 1,638 $ 7,146,147

Allowance for Losses on Loans

Allowance for Losses on Loans	3 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Allowance for Losses on Loans	Allowance for Losses on Loans For a detailed discussion of loans and credit quality, including accounting policies and the CECL methodology used to estimate the allowance for credit losses, see Note A "Summary of Significant Accounting Policies." The following tables summarize the activity in the allowance for loan losses by loan portfolio segment and class. Three Months Ended December 31, 2023 Beginning Allowance Charge-offs Recoveries Provision & Ending Allowance (In thousands) Commercial loans Multi-family $ 13,155 $ — $ — $ 636 $ 13,791 Commercial real estate 28,842 — 2 163 29,007 Commercial & industrial 58,773 (62) 32 2,093 60,836 Construction 29,408 — — (545) 28,863 Land - acquisition & development 7,016 (18) 50 (390) 6,658 Total commercial loans 137,194 (80) 84 1,957 139,155 Consumer loans Single-family residential 28,029 — 120 407 28,556 Construction - custom 2,781 — — (519) 2,262 Land - consumer lot loans 3,512 — 9 (176) 3,345 HELOC 2,859 — 1 113 2,973 Consumer 2,832 (213) 192 218 3,029 Total consumer loans 40,013 (213) 322 43 40,165 Total ACL - loans $ 177,207 $ (293) $ 406 $ 2,000 $ 179,320 (1) Provision & transfer amounts within the table do not include provision recapture from unfunded commitments of $2,000,000. Three Months Ended December 31, 2022 Beginning Allowance Charge-offs Recoveries Provision & Ending Allowance (In thousands) Commercial loans Multi-family $ 12,013 $ — $ — $ 311 $ 12,324 Commercial real estate 25,814 — 4 1,562 27,380 Commercial & industrial 57,210 (82) 32 6,713 63,873 Construction 26,161 — — (28) 26,133 Land - acquisition & development 12,278 — 16 (3,722) 8,572 Total commercial loans 133,476 (82) 52 4,836 138,282 Consumer loans Single-family residential 25,518 — 430 (473) 25,475 Construction - custom 3,410 — — 90 3,500 Land - consumer lot loans 5,047 — — (905) 4,142 HELOC 2,482 — 1 105 2,588 Consumer 2,875 (146) 234 (153) 2,810 Total consumer loans 39,332 (146) 665 (1,336) 38,515 Total loans $ 172,808 $ (228) $ 717 $ 3,500 $ 176,797 (1) Provision & transfer amounts within the table do not include provision recapture from unfunded commitments of $1,000,000 The Company recorded no provision for credit losses for the three months ended December 31, 2023, compared with a provision for credit losses of $2,500,000 for the three months ended December 31, 2022. The lack of provision in the three months ended December 31, 2023 was primarily due to a stable loan receivable balance and continued strong credit performance. The increase in the overall ACL was offset by the equal decrease in the reserve for unfunded commitments. The provision for the three months ended December 31, 2022 was primarily due to reserving for growth in loans receivable and changes in composition of the loan portfolio. Recoveries, net of charge-offs, totaled $113,000 for the three months ended December 31, 2023, compared to $489,000 during the three months ended December 31, 2022. Non-performing assets were $55,388,000, or 0.24% of total assets, at December 31, 2023, compared to $57,924,000, or 0.26% of total assets, at September 30, 2023. Non-accrual loans were $45,258,000 at December 31, 2023, compared to $50,422,000 at September 30, 2023. Delinquencies, as a percent of total loans, were 0.33% at December 31, 2023, compared to 0.36% at September 30, 2023. The Company has an asset quality review function that analyzes its loan portfolio and reports the results of the review to its Board of Directors on a quarterly basis. The single-family residential, HELOC and consumer portfolios are evaluated based on their performance as a pool of loans, since no single loan is individually significant or judged by its risk rating, size or potential risk of loss. The construction, land, multi-family, commercial real estate and commercial and industrial loans are risk rated on a loan by loan basis to determine the relative risk inherent in specific borrowers or loans. Based on that risk rating, the loans are assigned a grade and classified as described in Note D The following tables provide the amortized cost of loans receivable based on risk rating categories as previously defined. December 31, 2023 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,913,692 $ 90,668 $ 18,097 $ — $ — $ 3,022,457 Commercial real estate 3,221,093 784 110,416 — — 3,332,293 Commercial & industrial 2,224,862 2,850 137,270 — — 2,364,982 Construction 1,675,149 — 20,357 — — 1,695,506 Land - acquisition & development 148,573 — 138 — — 148,711 Total commercial loans 10,183,369 94,302 286,278 — — 10,563,949 Consumer loans Single-family residential 6,477,005 — 18,444 — — 6,495,449 Construction - custom 263,550 — 88 — — 263,638 Land - consumer lot loans 118,860 — 57 — — 118,917 HELOC 246,541 — 604 — — 247,145 Consumer 74,708 — 136 — — 74,844 Total consumer loans 7,180,664 — 19,329 — — 7,199,993 Total $ 17,364,033 $ 94,302 $ 305,607 $ — $ — $ 17,763,942 Total grade as a % of total loans 97.75 % 0.53 % 1.72 % — % — % September 30, 2023 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total Gross Loans (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,772,538 $ 90,428 $ 23,628 $ — $ — $ 2,886,594 Commercial real estate 3,207,596 4,847 97,658 — — 3,310,101 Commercial & industrial 2,164,876 6,647 143,795 — — 2,315,318 Construction 1,818,266 — 20,670 — — 1,838,936 Land - acquisition & development 156,390 — 271 — — 156,661 Total commercial loans 10,119,666 101,922 286,022 — — 10,507,610 Consumer loans Single-family residential 6,370,936 — 18,054 — — 6,388,990 Construction - custom 324,363 — 88 — — 324,451 Land - consumer lot loans 124,588 — 254 — — 124,842 HELOC 237,018 — 736 — — 237,754 Consumer 70,098 — 12 — — 70,110 Total consumer loans 7,127,003 — 19,144 — — 7,146,147 Total loans $ 17,246,669 $ 101,922 $ 305,166 $ — $ — $ 17,653,757 Total grade as a % of total gross loans 97.69 % 0.58 % 1.73 % — % — % The following tables provide information on the amortized cost of loans receivable based on borrower payment activity. December 31, 2023 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 3,022,325 100.0 % $ 132 — % Commercial real estate 3,308,010 99.3 24,283 0.7 Commercial & industrial 2,360,545 99.8 4,437 0.2 Construction 1,695,506 100.0 — 0.0 Land - acquisition & development 148,711 100.0 — — Total commercial loans 10,535,097 99.7 28,852 0.3 Consumer loans Single-family residential 6,480,053 99.8 15,396 0.2 Construction - custom 263,550 100.0 88 — Land - consumer lot loans 118,860 100.0 57 0.0 HELOC 246,542 99.8 603 0.2 Consumer 74,582 99.6 262 0.4 Total consumer loans 7,183,587 99.8 16,406 0.2 Total loans $ 17,718,684 99.7 % $ 45,258 0.3 % September 30, 2023 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,881,467 99.8 % $ 5,127 0.2 % Commercial real estate 3,286,666 99.3 23,435 0.7 Commercial & industrial 2,309,236 99.7 6,082 0.3 Construction 1,838,936 100.0 — — Land - acquisition & development 156,661 100.0 — — Total commercial loans 10,472,966 99.7 34,644 0.3 Consumer loans Single-family residential 6,374,072 99.8 14,918 0.2 Construction - custom 324,363 100.0 88 — Land - consumer lot loans 124,833 100.0 9 — HELOC 237,018 99.7 736 0.3 Consumer 70,083 100.0 27 0.0 Total consumer loans 7,130,369 99.8 15,778 0.2 Total loans $ 17,603,335 99.7 % $ 50,422 0.3 %

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements FASB ASC 820, Fair Value Measurement ("ASC 820") defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 also establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value: Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active exchange markets that the entity has the ability to access as of the measurement date. Level 2: Significant other observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active and other inputs that are observable or can be corroborated by observable market data. Level 3: Significant unobservable inputs that reflect a company’s own assumptions about the assumptions that market participants would use in pricing an asset or liability. The Company has established and documented the process for determining the fair values of its assets and liabilities, where applicable. Fair value is based on quoted market prices, when available, for identical or similar assets or liabilities. In the absence of quoted market prices, fair value is determined using valuation models or third-party appraisals. The following is a description of the valuation methodologies used to measure and report the fair value of financial assets and liabilities on a recurring or nonrecurring basis. Measured on a Recurring Basis Available-for-Sale Securities and Derivative Contracts Securities available for sale are recorded at fair value on a recurring basis. The fair value of debt securities are priced using model pricing based on the securities' relationship to other benchmark quoted prices as provided by an independent third party, and under GAAP are considered a Level 2 input method. Securities that are traded on active exchanges are measured using the closing price in an active market and are considered a Level 1 input method. The Company offers interest rate swaps to its variable rate borrowers who want to manage their interest rate risk. At the same time, the Company enters into the opposite trade with a counter party to offset its interest rate risk. The Company has also entered into commercial loan hedges, mortgage pool hedges and borrowings hedges using interest rate swaps. The fair value of these interest rate swaps are estimated by a third-party pricing service using a discounted cash flow technique. These are considered a Level 2 input method. The following tables present the balance and level in the fair value hierarchy of assets and liabilities that are measured at fair value on a recurring basis (with the exception of those measured using the NAV practical expedient). December 31, 2023 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 232,359 $ — $ 232,359 Asset-backed securities — 561,304 — 561,304 Municipal bonds — 35,206 — 35,206 Corporate debt securities — 248,813 — 248,813 Mortgage-backed securities Agency pass-through certificates — 940,763 — 940,763 Total available-for-sale securities — 2,018,445 — 2,018,445 Client swap program hedges — 55,631 — 55,631 Commercial loan fair value hedges — 2,061 — 2,061 Mortgage loan fair value hedges — 22,244 — 22,244 Borrowings cash flow hedges — 143,846 — 143,846 Total financial assets $ — $ 2,242,227 $ — $ 2,242,227 Financial Liabilities Client swap program hedges $ — $ 56,392 $ — $ 56,392 Total financial liabilities $ — $ 56,392 $ — $ 56,392 September 30, 2023 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 217,053 $ — $ 217,053 Asset-backed securities — 588,016 588,016 Municipal bonds — 34,662 — 34,662 Corporate debt securities — 242,522 — 242,522 Mortgage-backed securities Agency pass-through certificates — 912,844 — 912,844 Total available-for-sale securities — 1,995,097 — 1,995,097 Client swap program hedges — 78,797 — 78,797 Commercial loan fair value hedges — 3,405 — 3,405 Mortgage loan fair value hedges — 46,396 — 46,396 Borrowings cash flow hedges — 184,373 — 184,373 Total financial assets $ — $ 2,308,068 $ — $ 2,308,068 Financial Liabilities Client swap program hedges $ — $ 79,668 $ — $ 79,668 Total financial liabilities $ — $ 79,668 $ — $ 79,668 Measured on a Nonrecurring Basis Certain assets and liabilities are measured at fair value on a nonrecurring basis after initial recognition such as collateral dependent loans and real estate owned ("REO"). REO consists principally of properties acquired through foreclosure. From time to time, and on a nonrecurring basis, adjustments using fair value measurements are recorded to reflect increases or decreases based on the discounted cash flows, the current appraisal or estimated value of the collateral or REO property. When management determines that the fair value of the collateral or the REO requires additional adjustments, either as a result of an updated appraised value or when there is no observable market price, the Company classifies the collateral dependent loan or real estate owned as Level 3. Level 3 assets recorded at fair value on a nonrecurring basis at December 31, 2023 included loans for which an allowance was established or a partial charge-off was recorded based on the fair value of collateral, as well as real estate owned where the fair value of the property was less than the cost basis. The following tables present the aggregated balance of assets that were measured at fair value on a nonrecurring basis at December 31, 2023 and December 31, 2022, and the total gains (losses) resulting from those fair value adjustments during the respective periods. The estimated fair value measurements are shown gross of estimated selling costs. December 31, 2023 Three Months Ended December 31, 2023 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ 781 $ 781 $ (158) Real estate owned (2) — — — — — Balance at end of period $ — $ — $ 781 $ 781 $ (158) (1) The gains (losses) represent re-measurements of collateral-dependent loans. (2) The gains (losses) represent aggregate write-downs and charge-offs on real estate owned. December 31, 2022 Three Months Ended December 31, 2022 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ — $ — $ (123) Real estate owned (2) — — — — — Balance at end of period $ — $ — $ — $ — $ (123) (1) The gains (losses) represent re-measurements of collateral-dependent loans. (2) The gains (losses) represent aggregate write-downs and charge-offs on real estate owned. At December 31, 2023, there was $121,000 in foreclosed residential real estate properties held as REO. The recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings were in process was $3,338,000. Fair Values of Financial Instruments FASB ASC 825, Financial Instruments ("ASC 825") requires disclosure of fair value information about financial instruments, whether or not recognized on the statement of financial condition, for which it is practicable to estimate those values. Certain financial instruments and all non-financial instruments are excluded from the disclosure requirements. Accordingly, the aggregate fair value estimates presented do not reflect the underlying fair value of the Company. Although management is not aware of any factors that would materially affect the estimated fair value amounts presented below, such amounts have not been comprehensively revalued for purposes of these financial statements since the dates shown, and therefore, estimates of fair value subsequent to those dates may differ significantly from the amounts presented below. December 31, 2023 September 30, 2023 Level in Fair Value Hierarchy Carrying Estimated Carrying Estimated ($ in thousands) Financial assets Cash and cash equivalents 1 $ 1,144,774 $ 1,144,774 $ 980,649 $ 980,649 Available-for-sale securities U.S. government and agency securities 2 232,359 232,359 217,053 217,053 Asset-backed securities 2 561,304 561,304 588,016 588,016 Municipal bonds 2 35,206 35,206 34,662 34,662 Corporate debt securities 2 248,813 248,813 242,522 242,522 Mortgage-backed securities Agency pass-through certificates 2 940,763 940,763 912,844 912,844 Total available-for-sale securities 2,018,445 2,018,445 1,995,097 1,995,097 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 2 415,079 370,942 423,586 355,188 Total held-to-maturity securities 415,079 370,942 423,586 355,188 Loans receivable 3 17,584,622 16,876,965 17,476,550 16,559,758 FHLB stock 2 137,940 137,940 126,820 126,820 Other assets - client swap program hedges 2 55,631 55,631 78,797 78,797 Other assets - commercial fair value loan hedges 2 2,061 2,061 3,405 3,405 Other assets - mortgage loan fair value hedges 2 22,244 22,244 46,396 46,396 Other assets - borrowings cash flow hedges 2 143,846 143,846 184,373 184,373 Financial liabilities Time deposits 2 5,380,723 5,363,731 5,305,016 5,232,689 Borrowings 2 3,875,000 3,867,812 3,650,000 3,653,229 Other liabilities - client swap program hedges 2 56,392 56,392 79,668 79,668 The following methods and assumptions were used to estimate the fair value of financial instruments: Cash and cash equivalents – The carrying amount of these items is a reasonable estimate of their fair value. Available-for-sale securities and held-to-maturity securities – Securities at fair value are primarily priced using model pricing based on the securities' relationship to other benchmark quoted prices as provided by an independent third party, and are considered a Level 2 input method. Equity securities that are exchange traded are considered a Level 1 input method. Loans receivable – Fair values are estimated first by stratifying the portfolios of loans with similar financial characteristics. Loans are segregated by type such as multi-family real estate, residential mortgage, construction, commercial, consumer and land loans. Each loan category is further segmented into fixed- and adjustable-rate interest terms. For residential mortgages and multi-family loans, the bank determined that its best exit price was by securitization. MBS benchmark prices are used as a base price, with further loan level pricing adjustments made based on individual loan characteristics such as FICO score, LTV, Property Type and occupancy. For all other loan categories an estimate of fair value is then calculated based on discounted cash flows using a discount rate offered and observed in the market on similar products, plus an adjustment for liquidity to reflect the non-homogeneous nature of the loans, as well as an annual loss rate based on historical losses to arrive at an estimated exit price fair value. Fair value for impaired loans is also based on recent appraisals or estimated cash flows discounted using rates commensurate with risk associated with the estimated cash flows. Assumptions regarding credit risk, cash flows and discount rates are judgmentally determined using available market information and specific borrower information. FHLB stock – The fair value is based upon the par value of the stock that equates to its carrying value. Time deposits – The fair value of time deposits is estimated by discounting the estimated future cash flows using rates offered for deposits with similar remaining maturities. Borrowings – The fair value of FHLB advances and FRB borrowings is estimated by discounting the estimated future cash flows using rates currently available to the Company for debt with similar remaining maturities. Interest rate swaps – The Company offers interest rate swaps to its variable rate borrowers who want to manage their interest rate risk. At the same time, the Company enters into the opposite trade with a counterparty to offset its interest rate risk. The Company also uses interest rate swaps for various fair value hedges and cash flow hedges. The fair value of these interest rate swaps is estimated by a third-party pricing service using a discounted cash flow technique. The following tables provide details about the amortized cost and fair value of available-for-sale and held-to-maturity securities. December 31, 2023 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due Within 1 year $ 1,750 $ — $ (5) $ 1,745 6.07 % 1 to 5 years 16,747 8 (305) 16,450 4.54 % 5 to 10 years 110,295 189 (173) 110,311 6.01 Over 10 years 103,594 267 (8) 103,853 6.09 Asset-backed securities 1 to 5 years 17,693 — (766) 16,927 6.08 5 to 10 years 31,469 14 (205) 31,278 6.23 Over 10 years 519,103 316 (6,320) 513,099 6.37 Corporate debt securities due 1 to 5 years 152,022 479 (1,196) 151,305 5.15 5 to 10 years 112,923 — (15,415) 97,508 3.87 Municipal bonds due 5 to 10 years 5,712 — (298) 5,414 3.00 Over 10 years 29,822 95 (125) 29,792 5.85 Mortgage-backed securities Agency pass-through certificates 1,000,184 707 (60,128) 940,763 3.44 2,101,314 2,075 (84,944) 2,018,445 4.69 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 415,079 27 (44,164) 370,942 2.88 415,079 27 (44,164) 370,942 2.88 $ 2,516,393 $ 2,102 $ (129,108) $ 2,389,387 4.39 % September 30, 2023 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due Within 1 year $ 3,501 $ — $ (36) $ 3,465 6.06 % 1 to 5 years 18,894 — (563) 18,331 4.70 % 5 to 10 years 87,922 177 — 88,099 5.76 Over 10 years 106,340 831 (13) 107,158 5.84 Asset-backed securities 1 to 5 years 18,579 — (715) 17,864 6.06 5 to 10 years 36,875 2 (99) 36,778 6.11 Over 10 years 539,911 578 (7,115) 533,374 6.35 Corporate debt securities due 1 to 5 years 151,893 895 (1,787) 151,001 5.14 5 to 10 years 113,221 — (21,700) 91,521 3.87 Municipal bonds due 5 to 10 years 5,720 — (701) 5,019 3.00 Over 10 years 29,832 361 (550) 29,643 5.85 Mortgage-backed securities Agency pass-through certificates 1,005,928 66 (93,150) 912,844 3.39 2,118,616 2,910 (126,429) 1,995,097 4.64 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 423,586 — (68,398) 355,188 2.88 423,586 — (68,398) 355,188 2.88 $ 2,542,202 $ 2,910 $ (194,827) $ 2,350,285 4.35 % The Company purchased $49,380,000 of AFS investment securities during the three months ended December 31, 2023 and purchased $115,909,000 of AFS securities during the three months ended December 31, 2022. Sales of AFS securities totaled $2,624,000 during the three months ended December 31, 2023 compared to no sales during the prior year same period. For HTM investment securities, there were no purchases during the three months ended December 31, 2023 and no purchases during the three months ended December 31, 2022. There were no sales of HTM investment securities during the three months ended December 31, 2023 or December 31, 2022. Substantially all of the agency mortgage-backed securities have contractual due dates that exceed 25 years. The Company elected to exclude AIR from the amortized cost basis of debt securities disclosed throughout this footnote. For AFS securities, AIR totaled $8,270,000 and $8,641,000 as of December 31, 2023 and September 30, 2023, respectively. For HTM debt securities, AIR totaled $992,000 and $1,013,000 as of December 31, 2023 and September 30, 2023, respectively. AIR for securities is included in the Interest receivable line item balance on the Company’s consolidated statements of financial condition. The following tables show the gross unrealized losses and fair value of securities as of December 31, 2023 and September 30, 2023, by length of time that individual securities in each category have been in a continuous loss position. There were 220 and 231 securities with an unrealized loss as of December 31, 2023 and September 30, 2023, respectively. December 31, 2023 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Corporate debt securities $ — $ — $ (16,611) $ 174,074 $ (16,611) $ 174,074 Municipal bonds — — (423) 15,111 (423) 15,111 U.S. government and agency securities (181) 134,687 (310) 13,720 (491) 148,407 Asset-backed securities — — (7,291) 522,583 (7,291) 522,583 Mortgage-backed securities (72) 18,243 (60,056) 756,173 (60,128) 774,416 (253) 152,930 (84,691) 1,481,661 (84,944) 1,634,591 Held-to-maturity securities Mortgage-backed securities — — (44,164) 369,265 (44,164) 369,265 $ (253) $ 152,930 $ (128,855) $ 1,850,926 $ (129,108) $ 2,003,856 September 30, 2023 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Corporate debt securities $ — $ — $ (23,487) $ 167,452 $ (23,487) $ 167,452 Municipal bonds due — — (1,250) 14,302 (1,250) 14,302 U.S. government and agency securities (13) 14,917 (599) 21,795 (612) 36,712 Asset-backed securities (2,142) 86,800 (5,788) 445,454 (7,930) 532,254 Mortgage-backed securities (2,030) 142,235 (91,120) 744,010 (93,150) 886,245 (4,185) 243,952 (122,244) 1,393,013 (126,429) 1,636,965 Held-to-maturity securities Mortgage-backed securities (15) 1,424 (68,383) 353,764 (68,398) 355,188 $ (4,200) $ 245,376 $ (190,627) $ 1,746,777 $ (194,827) $ 1,992,153 The decline in fair value since purchase is attributable to changes in interest rates. Substantially all of the Company’s HTM debt securities are issued by U.S. government agencies or U.S. government-sponsored enterprises. These securities carry the explicit and/or implicit guarantee of the U.S. government and have a long history of zero credit loss. Therefore, the Company did not record an allowance for credit losses for these securities as of December 31, 2023 or September 30, 2023. The Company does not consider AFS or HTM investments to have any credit impairment. The Company does not believe that the AFS debt securities that were in an unrealized loss position have any credit loss impairment as of December 31, 2023 or September 30, 2023. The Company does not intend to sell the investment securities that were in an unrealized loss position and it is more likely than not the Company will not be required to sell the investment securities before recovery of their amortized cost basis, which may be at maturity. AFS debt securities issued by U.S. government agencies or U.S. government-sponsored enterprises carry the explicit and/or implicit guarantee of the U.S. government and have a long history of zero credit loss. Corporate debt securities and municipal bonds are considered to have an issuer of high credit quality and the decline in fair value is due to changes in interest rates and other market conditions. The issuer continues to make timely principal and interest payments on the bonds. The fair value is expected to recover as the bonds approach maturity.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	3 Months Ended
	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activities The following tables present the fair value, notional amount and balance sheet classification of derivative assets and liabilities at December 31, 2023 and September 30, 2023. December 31, 2023 Derivative Assets Derivative Liabilities Interest rate contract purpose Balance Sheet Location Notional Fair Value Balance Sheet Location Notional Fair Value (In thousands) (In thousands) Client swap program hedges Other assets $ 896,485 $ 55,631 Other liabilities $ 896,485 $ 56,392 Commercial loan fair value hedges Other assets 37,042 2,061 Other liabilities — — Mortgage loan fair value hedges Other assets 970,000 22,244 Other liabilities — — Borrowings cash flow hedges Other assets 1,000,000 143,846 Other liabilities — — $ 2,903,527 $ 223,782 $ 896,485 $ 56,392 September 30, 2023 Derivative Assets Derivative Liabilities Interest rate contract purpose Balance Sheet Location Notional Fair Value Balance Sheet Location Notional Fair Value (In thousands) (In thousands) Client swap program hedges Other assets $ 806,744 $ 78,797 Other liabilities $ 806,744 $ 79,668 Commercial loan fair value hedges Other assets 39,661 3,405 Other liabilities — — Mortgage loan fair value hedges Other assets 670,000 46,396 Other liabilities — — Borrowings cash flow hedges Other assets 1,000,000 184,373 Other liabilities — — $ 2,516,405 $ 312,971 $ 806,744 $ 79,668 The Company enters into interest rate swaps to hedge interest rate risk. These arrangements include hedges of individual fixed rate commercial loans and also hedges of a specified portion of pools of prepayable fixed rate mortgage loans under the "portfolio layer" method. These relationships qualify as fair value hedges under FASB ASC 815, Derivatives and Hedging ("ASC 815"), which provides for offsetting of the recognition of gains and losses of the respective interest rate swap and the hedged items. Gains and losses on interest rate swaps designated in these hedge relationships, along with the offsetting gains and losses on the hedged items attributable to the hedged risk, are recognized in current earnings within the same income statement line item. Upon electing to apply ASC 815 fair value hedge accounting, the carrying value of the hedged item is adjusted to reflect the cumulative impact of changes in fair value attributable to the hedged risk. The hedge basis adjustment remains with the hedged item until the hedged item is de-recognized from the balance sheet. The following tables present the impact of fair value hedge accounting on the carrying value of the hedged items at December 31, 2023 and September 30, 2023. (In thousands) December 31, 2023 Balance sheet line item in which hedged item is recorded Carrying value of hedged items Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items Loans receivable (1) (2) $ 6,246,208 $ (23,255) $ 6,246,208 $ (23,255) (1) Includes the amortized cost basis of the closed mortgage loan portfolios used to designate the hedging relationships in which the hedged items are a portfolio layer expected to be remaining at the end of the hedging relationships. At December 31, 2023, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $6,211,195,000, the cumulative basis adjustment associated with the hedging relationships was $(21,277,000), and the amount of the designated hedged items was $970,000,000. (2) Includes the amortized cost basis of commercial loans designated in fair value hedging relationships. At December 31, 2023, the amortized cost basis of the hedged commercial loans was $35,013,000 and the cumulative basis adjustment associated with the hedging relationships was $(1,978,000). (In thousands) September 30, 2023 Balance sheet line item in which hedged item is recorded Carrying value of hedged items Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items Loans receivable (1) (2) $ 1,816,870 $ (48,865) $ 1,816,870 $ (48,865) (1) Includes the amortized cost basis of the closed mortgage loan portfolios used to designate the hedging relationships in which the hedged items are the last layer expected to be remaining at the end of the hedging relationships. At September 30, 2023, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $1,780,503,000, the cumulative basis adjustment associated with the hedging relationships was $(45,622,000), and the amount of the designated hedged items was $670,000,000. (2) Includes the amortized cost basis of commercial loans designated in fair value hedging relationships. At September 30, 2023, the amortized cost basis of the hedged commercial loans was $36,367,000 and the cumulative basis adjustment associated with the hedging relationships was $(3,243,000). The Company has entered into interest rate swaps to convert certain short-term borrowings to fixed rate payments. The primary purpose of these hedges is to mitigate the risk of changes in future cash flows resulting from increasing interest rates. For qualifying cash flow hedges under ASC 815, gains and losses on the interest rate swaps are recorded in accumulated other comprehensive income ("AOCI") and then reclassified into earnings in the same period the hedged cash flows affect earnings and within the same income statement line item as the hedged cash flows. As of December 31, 2023, the maturities for hedges of adjustable rate borrowings ranged from one year to six years, with the weighted average being 5.3 years. The following table presents the impact of derivative instruments (cash flow hedges on borrowings) on AOCI for the periods presented. (In thousands) Three Months Ended December 31, Amount of gain/(loss) recognized in AOCI on derivatives in cash flow hedging relationships 2023 2022 Interest rate contracts: Pay fixed/receive floating swaps on borrowings cash flow hedges $ (40,527) $ (6,806) Total pre-tax gain/(loss) recognized in AOCI $ (40,527) $ (6,806) The following tables present the gain (loss) on derivative instruments in fair value and cash flow accounting hedging relationships under ASC 815 for the periods presented. Three Months Ended December 31, 2023 Three Months Ended December 31, 2022 Interest income on loans receivable Interest expense on FHLB advances Interest income on loans receivable Interest expense on FHLB advances (In thousands) (In thousands) Interest income/(expense), including the effects of fair value and cash flow hedges $ 245,792 $ (37,938) $ 203,946 $ (18,974) Gain/(loss) on fair value hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 5,493 $ 3,167 Recognized on derivatives (25,496) (2,849) Recognized on hedged items 25,610 3,132 Net income/(expense) recognized on fair value hedges $ 5,607 $ 3,450 Gain/(loss) on cash flow hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 11,847 $ 7,274 Amount of derivative gain/(loss) reclassified from AOCI into interest income/expense — — Net income/(expense) recognized on cash flow hedges $ 11,847 $ 7,274 The Company periodically enters into certain interest rate swap agreements in order to provide commercial loan customers the ability to convert from variable to fixed interest rate payments, while the Company retains a variable rate loan. Under these agreements, the Company enters into a variable rate loan agreement and a swap agreement with the client. The swap agreement effectively converts the client’s variable rate loan into a fixed rate. The Company enters into a corresponding swap agreement with a third party in order to offset its exposure on the variable and fixed components of the client's swap agreement. The interest rate swaps are derivatives under ASC 815, with changes in fair value recorded in earnings. The impact to the statement of operations for the three months ended December 31, 2023 was an increase in other income of $109,000. There was no net impact to the statement of operations for the three months ended December 31, 2022 as the changes in fair value of the receive fixed swap and pay fixed swap offset each other. The following tables present the impact of derivative instruments (client swap program) that are not designated in accounting hedges under ASC 815 for the periods presented. (In thousands) Three Months Ended December 31, Derivative instruments Classification of gain/(loss) recognized in income on derivative instrument 2023 2022 Interest rate contracts: Pay fixed/receive floating swap Other noninterest income $ (28,709) $ (3,878) Receive fixed/pay floating swap Other noninterest income 28,818 3,878 $ 109 $ —

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers Since net interest income on financial assets and liabilities is outside the scope of ASU No. 2014-09, Revenue from Contracts with Customers ("ASC 606"), a significant majority of Company revenues are not subject to that guidance. Revenue streams that are within the scope of ASC 606 are presented within non-interest income and are, in general, recognized as revenue at the same time the Company's obligation to the customer is satisfied. Most of the Company's customer contracts that are within the scope of the new guidance are cancelable by either party without penalty and are short-term in nature. These sources of revenue include depositor and other consumer and business banking fees, commission income, as well as debit and credit card interchange fees. In scope revenue streams represented approximately 3.6% of Company total revenue for the three months ended December 31, 2023, compared to 3.9% for the three months ended December 31, 2022. As this standard is immaterial to the consolidated financial statements, the Company has omitted certain disclosures in ASC 606, including the disaggregation of revenue table. Sources of non-interest income within the scope of the guidance include the following: Deposit related and other service charges (recognized in Deposit fee income) - The Company's deposit accounts are governed by standardized contracts customary in the industry. Revenues are earned at a point in time or over time (monthly) from account maintenance fees and charges for specific transactions such as wire transfers, stop payment orders, overdrafts, debit card replacements, check orders and cashier’s checks. The Company’s performance obligation related to each of these fees is generally satisfied, and the related revenue recognized, at the time the service is provided (point in time or monthly). The Company is principal in each of these contracts. Debit and Credit Card Interchange Fees (recognized in Deposit fee income) - The Company receives interchange fees from the debit card or credit card payment network based on transactions involving debit or credit cards issued by the Company, generally measured as a percentage of the underlying transaction. Interchange fees from debit and credit card transactions are recognized as the transaction processing services are provided by the network. The Company acts as an agent in the card payment network arrangement, so the interchange fees are recorded net of any expenses paid to the principal (the card payment network in this case). Insurance Agency Commissions (recognized in Other income)

Commitment and Contingencies

Commitment and Contingencies	3 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Commitments - The Company’s lease commitments consist primarily of real estate property for branches and office space under various non-cancellable operating leases that expire between 2024 and 2070. The majority of the leases contain renewal options and provisions for increases in rental rates based on a predetermined schedule or an agreed upon index. Financial Instruments with Off-Balance Sheet Risk - The only material off-balance-sheet credit exposures are unfunded loan commitments, which had a combined balance of $3,180,001,000 and $3,625,333,000 at December 31, 2023 and September 30, 2023, respectively. The reserve was $22,500,000 as of December 31, 2023, which is a decrease from $24,500,000 at September 30, 2023. See Note A "Summary of Significant Accounting Policies" for details regarding the reserve methodology. Legal Proceedings - The Company and its subsidiaries are from time to time defendants in and are threatened with various legal proceedings arising from regular business activities. Management, after consulting with legal counsel, is of the opinion that the ultimate liability, if any, resulting from these pending or threatened actions and proceedings will not have a material effect on the financial statements of the Company.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net income	$ 58,453	$ 79,509

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation - The Company has prepared the consolidated unaudited interim financial statements included in this report. All intercompany transactions and accounts have been eliminated in consolidation. The preparation of financial statements, in conformity with accounting principles generally accepted in the United States of America (“GAAP”), requires management to make estimates and assumptions that affect amounts reported in the financial statements. Actual results could differ from these estimates. In the opinion of management, all adjustments (consisting only of normal recurring adjustments) necessary for a fair presentation are reflected in the interim financial statements. The information included in this Form 10-Q should be read in conjunction with the financial statements and related notes contained in the Company's 2023 Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on November 17, 2023 ("2023 Annual Financial Statements"). Interim results are not necessarily indicative of results for a full year.
Equity Securities	Equity Securities - The Company records equity securities within Other assets in its Consolidated Statements of Financial Condition. These equity investments are accounted for under different methods. • Low-income housing tax credit investments are accounted for under the proportional amortization method. • For equity investments where the Company has significant influence, the Company applies the equity method of accounting, which adjusts the carrying value of the investment to recognize a proportionate share of the financial results of the investment entity, regardless of whether any distribution is made. Any adjustments to the fair value of these investments are recorded in Other income in the Consolidated Statements of Operations. • For investments in certain nonmarketable equity securities investments where the equity method of accounting is not applicable, the Company applies the fair value method. Any adjustments to the fair value of these investments are recorded in Other income in the Consolidated Statements of Operations. Fair value is determined by reference to readily determinable market values, if applicable. As these investments do not have readily determinable fair values, they are generally accounted for at cost minus impairment, if any, plus or minus changes resulting from observable transactions involving the same or similar investments from the same issuer. This practice is referred to as the measurement alternative. • Equity investments in qualified real estate funds can use the NAV expedient for fair value measurement. Under this method, the net asset value (NAV) is determined by the fund as fair value for the investment. At December 31, 2023, equity investments held by the Company and recorded at NAV had a carrying amount of $36,708,000 and a remaining unfunded commitment of $5,578,000. These NAV based investments cannot be transferred without consent and we do not have redemption rights. Equity investments measured at NAV are not classified in the fair value hierarchy.
Allowance for Credit Losses (Loans Receivable) and Allowance for Credit Losses (Held-to-Maturity Debt Securities)	Allowance for Credit Losses (Loans Receivable) - The Company maintains an allowance for credit losses (“ACL”) for the expected credit losses of the loan portfolio as well as unfunded loan commitments. The amount of ACL is based on ongoing, quarterly assessments by management. The current expected credit loss methodology (“CECL”) requires an estimate of the credit losses expected over the life of an exposure (or pool of exposures). The ACL consists of the allowance for loan losses and the reserve for unfunded commitments. The estimate of expected credit losses under the CECL methodology is based on relevant information about past events, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amounts. Historical loss experience is generally the starting point for estimating expected credit losses. We then consider whether the historical loss experience should be adjusted for asset-specific risk characteristics or current conditions at the reporting date that did not exist over the period that historical experience was based for each loan type. Finally, we consider forecasts about future economic conditions or changes in collateral values that are reasonable and supportable. Portfolio segment is defined as the level at which an entity develops and documents a systematic methodology to determine its ACL. The Company has designated two loan portfolio segments, commercial loans and consumer loans. These loan portfolio segments are further disaggregated into classes, which represent loans of similar type, risk characteristics, and methods for monitoring and assessing credit risk. The commercial loan portfolio segment is disaggregated into five classes: multi-family, commercial real estate, commercial and industrial, construction, and land acquisition and development. The risk of loss for the commercial loan portfolio segment is generally most indicated by the credit risk rating assigned to each borrower. Commercial loan risk ratings are determined by experienced senior credit officers based on specific facts and circumstances and are subject to periodic review by an independent internal team of credit specialists. The consumer loan portfolio segment is disaggregated into five classes: single-family-residential mortgage, custom construction, consumer lot loans, home equity lines of credit, and other consumer. The risk of loss for the consumer loan portfolio segment is generally most indicated by delinquency status and general economic factors. Each commercial and consumer loan portfolio class may also be further segmented based on risk characteristics. For the majority of the Company's loan portfolio classes, the historical loss experience is determined using a cohort methodology. This method pools loans into groups (“cohorts”) sharing similar risk characteristics and tracks each cohort’s net charge-offs over the lives of the loans to calculate a historical loss rate. The historical loss rates for each cohort are then averaged to calculate an overall historical loss rate which is applied to the current loan balance to arrive at the quantitative baseline portion of the allowance for credit losses for the respective loan portfolio class. For certain loan portfolio classes, the Company determined there was not sufficient historical loss information to calculate a meaningful historical loss rate using the cohort methodology. For any such loan portfolio class, the weighted-average remaining maturity (“WARM”) methodology is being utilized until sufficient historical loss data is obtained. The WARM method multiplies an average annual loss rate by the expected remaining life of the loan pool to arrive at the quantitative baseline portion of the allowance for credit losses for the respective loan portfolio class. The Company also considers qualitative adjustments to the historical loss rate for each loan portfolio class. The qualitative adjustments for each loan class consider the conditions over the period from which historical loss experience was based and are split into two components: 1) asset or class specific risk characteristics or current conditions at the reporting date related to portfolio credit quality, remaining payments, volume and nature, credit culture and management, business environment or other management factors and 2) reasonable and supportable forecast of future economic conditions and collateral values. The Company performs a quarterly asset quality review which includes a review of forecasted gross charge-offs and recoveries, nonperforming assets, criticized loans, risk rating migration, delinquencies, etc. The asset quality review is performed by management and the results are used to consider a qualitative overlay to the quantitative baseline. The second qualitative adjustment noted above, economic conditions and collateral values, encompasses a one-year reasonable and supportable forecast period. The overlay adjustment for the reasonable and supportable forecast assumes an immediate reversion after the one-year forecast period to historical loss rates for the remaining life of the respective loan pool. The Company may establish a specific reserve for individually evaluated loans that do not share similar risk characteristics with the loans included in each respective loan pool if management deems it appropriate. If this occurs, these individually evaluated loans are removed from their respective pools and typically represent collateral dependent loans but may also include other non-performing loans. Allowance for Credit Losses (Held-to-Maturity Debt Securities) - For held-to-maturity (“HTM”) debt securities, the Company is required to utilize a CECL methodology to estimate expected credit losses. Substantially all of the Company’s HTM debt securities are issued by U.S. government agencies or U.S. government-sponsored enterprises. These securities carry the explicit and/or implicit guarantee of the U.S. government and have a long history of zero credit loss. See Note F "Fair Value Measurements" for more information about HTM debt securities. Allowance for Credit Losses (Available-for-Sale Debt Securities)
Accrued Interest Receivable	Accrued Interest Receivable - The Company made the following elections regarding accrued interest receivable (“AIR”): • Presenting accrued interest receivable balances separately from their underlying instruments within the consolidated statements of financial condition. • Excluding accrued interest receivable that is included in the amortized cost of financing receivables from related disclosure requirements. • Continuing the Company's policy to write off accrued interest receivable by reversing interest income in cases where the Company does not reasonably expect to receive payment. • Not measuring an allowance for credit losses for accrued interest receivable due to the Company’s policy of writing off uncollectible accrued interest receivable balances in a timely manner, as described above.
Non-Accrual and Collateral-Dependent Loans	Non-Accrual Loans - Loans are placed on non-accrual status when, in the judgment of management, the probability of collection of interest is deemed to be insufficient to warrant further accrual. When a loan is placed on non-accrual status, previously accrued but unpaid interest is deducted from interest income. The Bank does not accrue interest on loans 90 days or more past due. If payment is made on a loan so that the loan becomes less than 90 days past due, and the Bank expects full collection of principal and interest, the loan is returned to full accrual status. Any interest ultimately collected is credited to income in the period of recovery. A loan is charged-off when the loss is estimable and it is confirmed that the borrower is not expected to be able to meet contractual obligations. If a consumer loan is on non-accrual status before being modified, it will stay on non-accrual status following restructuring until it has been performing for at least six months, at which point it may be moved to accrual status. For commercial loans, six consecutive payments on newly restructured loan terms are required prior to returning the loan to accrual status. In some instances, after the required six consecutive payments are made, management will conclude that collection of the entire principal and interest due is still in doubt. In those instances, the loan will remain on non-accrual status. Collateral-Dependent Loans - A financial asset is considered collateral-dependent when the debtor is experiencing financial difficulty and repayment is expected to be provided substantially through the sale or operation of the collateral. For all classes of loans and leases deemed collateral-dependent, the Company elected the practical expedient to estimate expected credit losses based on the collateral’s fair value less cost to sell. In most cases, the Company records a partial charge-off to reduce the loan’s carrying value to the collateral’s fair value less cost to sell. Substantially all of the collateral consists of various types of real estate including residential properties; commercial properties such as retail centers, office buildings, and lodging; agriculture land; and vacant land.
Off-balance-sheet credit exposures	The reserve for unfunded commitments is recognized as a liability (other liabilities in the consolidated statements of financial condition), with adjustments to the reserve recognized through provision for credit losses in the consolidated statements of income. The reserve for unfunded commitments represents the expected lifetime credit losses on off-balance sheet obligations such as commitments to extend credit and standby letters of credit. However, a liability is not recognized for commitments that are unconditionally cancellable by the Company. The reserve for unfunded commitments is determined by estimating future draws, including the effects of risk mitigation actions, and applying the expected loss rates on those draws. Loss rates are estimated by utilizing the same loss rates calculated for the allowance for credit losses related to the respective loan portfolio class. See Note I “Commitments and Contingencies” for more information.
New Accounting Pronouncements	New Accounting Pronouncements In March 2023, the FASB issued ASU 2023-02, Investments - Equity Method and Joint Ventures (Topic 323) . The amendments in this ASU expand the population of tax credit investments for which an investor may elect to apply the proportional amortization method ("PAM") and require certain disclosures for tax credit investments. For public companies amendments in this ASU are effective for fiscal years beginning after December 15, 2023, with early adoption permitted. The Company has utilized PAM for low income housing tax credit investments. The Company does not expect this ASU to have a material effect on our consolidated financial statements. In October 2023, the FASB issued ASU 2023-6 Disclosure Improvements: Codification Amendments In Response to the SEC's Disclosure Update and Simplification Initiative to clarify or improve disclosure and presentation requirements on a variety of topics and align the requirements in the FASB accounting standard codification with the Securities and Exchange Commission regulations. The amendments will be effective for the Company only if the SEC removes the related disclosure requirement from its existing regulations no later than June 30, 2027. If the SEC timely removes such a related requirement from its existing regulations, the corresponding amendments within the ASU will become effective for the Company on the same date with early adoption permitted. The Company does not expect the amendments in this update to have a material impact on our consolidated financial statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures (Topic 280) to improve reportable segment disclosure requirements through enhanced disclosures about significant segment expenses. For public companies amendments in this ASU are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024 with early adoption permitted. The Company does not expect this ASU to have a material effect on our consolidated financial statements. In December 2023, the FASB issued ASU 2023-09 , Income Tax - Improvements to Income Tax Disclosures (Topic 740) which requires reporting companies to break out their income tax expense and tax rate reconciliation in more detail. For public
Fair Value Measurements	FASB ASC 820, Fair Value Measurement ("ASC 820") defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 also establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard describes three levels of inputs that may be used to measure fair value: Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active exchange markets that the entity has the ability to access as of the measurement date. Level 2: Significant other observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active and other inputs that are observable or can be corroborated by observable market data. Level 3: Significant unobservable inputs that reflect a company’s own assumptions about the assumptions that market participants would use in pricing an asset or liability. The Company has established and documented the process for determining the fair values of its assets and liabilities, where applicable. Fair value is based on quoted market prices, when available, for identical or similar assets or liabilities. In the absence of quoted market prices, fair value is determined using valuation models or third-party appraisals. The following is a description of the valuation methodologies used to measure and report the fair value of financial assets and liabilities on a recurring or nonrecurring basis. Measured on a Recurring Basis Available-for-Sale Securities and Derivative Contracts Securities available for sale are recorded at fair value on a recurring basis. The fair value of debt securities are priced using model pricing based on the securities' relationship to other benchmark quoted prices as provided by an independent third party, and under GAAP are considered a Level 2 input method. Securities that are traded on active exchanges are measured using the closing price in an active market and are considered a Level 1 input method. The Company offers interest rate swaps to its variable rate borrowers who want to manage their interest rate risk. At the same time, the Company enters into the opposite trade with a counter party to offset its interest rate risk. The Company has also entered into commercial loan hedges, mortgage pool hedges and borrowings hedges using interest rate swaps. The fair value of these interest rate swaps are estimated by a third-party pricing service using a discounted cash flow technique. These are considered a Level 2 input method.

Loans Receivable (Tables)

Loans Receivable (Tables)	3 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Schedule of Loans Receivable	The following table is a summary of loans receivable by loan portfolio segment and class. December 31, 2023 September 30, 2023 Gross loans by category (In thousands) (In thousands) Commercial loans Multi-family $ 3,054,426 15.8 % $ 2,907,086 14.8 % Commercial real estate 3,351,113 17.3 3,344,959 17.0 Commercial & industrial 2,371,393 12.3 2,321,717 11.8 Construction 2,868,207 14.8 3,318,994 16.9 Land - acquisition & development 190,732 1.0 201,538 1.0 Total commercial loans 11,835,871 61.2 12,094,294 61.6 Consumer loans Single-family residential 6,535,073 33.8 6,451,270 32.8 Construction - custom 543,748 2.8 672,643 3.4 Land - consumer lot loans 119,735 0.6 125,723 0.6 HELOC 243,742 1.2 234,410 1.2 Consumer 74,884 0.4 70,164 0.4 Total consumer loans 7,517,182 38.8 7,554,210 38.4 Total gross loans 19,353,053 100 % 19,648,504 100 % Less: Allowance for credit losses on loans 179,320 177,207 Loans in process 1,516,522 1,895,940 Net deferred fees, costs and discounts 72,589 98,807 Total loan contra accounts 1,768,431 2,171,954 Net loans $ 17,584,622 $ 17,476,550
Non-accrual Loans and Loans 90 Days or More Past Due and Accruing	The following table sets forth the amortized cost basis of non-accrual loans and loans 90 days or more past due and accruing. December 31, 2023 September 30, 2023 (In thousands, except ratio data) Non-accrual Non-accrual with no ACL 90 days or more past due and accruing Non-accrual Non-accrual with no ACL 90 days or more past due and accruing Commercial loans Multi-family $ 132 $ — $ — $ 5,127 $ — $ — Commercial real estate 24,283 — — 23,435 — — Commercial & industrial 4,437 — — 6,082 — — Construction — — — — — — Land - acquisition & development — — — — — — Total commercial loans 28,852 — — 34,644 — — Consumer loans Single-family residential 15,396 — — 14,918 — — Construction - custom 88 — — 88 — — Land - consumer lot loans 57 — — 9 — — HELOC 603 — — 736 — — Consumer 262 — — 27 — — Total consumer loans 16,406 — — 15,778 — — Total non-accrual loans $ 45,258 $ — $ — $ 50,422 $ — $ — % of total loans 0.25 % 0.29 %
Loan Delinquencies by Loan Portfolio and Class	The following tables provide details regarding loan delinquencies by loan portfolio and class. December 31, 2023 Days Delinquent Based on $ Amount of Loans % based Type of Loan Loans Receivable (Amortized Cost) Current 30 60 90 Total Delinquent (In thousands, except ratio data) Commercial Loans Multi-family $ 3,022,457 $ 3,022,325 $ — $ — $ 132 $ 132 — % Commercial real estate 3,332,293 3,307,076 934 — 24,283 25,217 0.76 Commercial & industrial 2,364,982 2,357,841 2,686 20 4,435 7,141 0.30 Construction 1,695,506 1,695,506 — — — — Land - acquisition & development 148,711 148,711 — — — — — Total commercial loans 10,563,949 10,531,459 3,620 20 28,850 32,490 0.31 Consumer Loans Single-family residential 6,495,449 6,473,306 6,131 4,065 11,947 22,143 0.34 Construction - custom 263,638 262,791 760 — 87 847 0.32 Land - consumer lot loans 118,917 118,524 336 — 57 393 0.33 HELOC 247,145 245,477 1,117 — 551 1,668 0.67 Consumer 74,844 74,328 208 47 261 516 0.69 Total consumer loans 7,199,993 7,174,426 8,552 4,112 12,903 25,567 0.36 Total Loans $ 17,763,942 $ 17,705,885 $ 12,172 $ 4,132 $ 41,753 $ 58,057 0.33 % Delinquency % 99.67% 0.07% 0.01% 0.24% 0.33% September 30, 2023 Days Delinquent Based on $ Amount of Loans % based Type of Loan Loans Receivable (Amortized Cost) Current 30 60 90 Total Delinquent (In thousands, except ratio data) Commercial Loans Multi-family $ 2,886,594 $ 2,886,462 $ — $ — $ 132 $ 132 — % Commercial real estate 3,310,101 3,285,673 848 145 23,435 24,428 0.74 Commercial & industrial 2,315,318 2,307,020 30 2,186 6,082 8,298 0.36 Construction 1,838,936 1,838,936 — — — — — Land - acquisition & development 156,661 156,661 — — — — — Total commercial loans 10,507,610 10,474,752 878 2,331 29,649 32,858 0.31 Consumer Loans Single-family residential 6,388,990 6,365,065 6,441 6,068 11,416 23,925 0.37 Construction - custom 324,451 320,987 760 2,617 87 3,464 1.07 Land - consumer lot loans 124,842 124,231 358 245 8 611 0.49 HELOC 237,754 235,708 1,050 314 682 2,046 0.86 Consumer 70,110 69,699 228 107 76 411 0.59 Total consumer loans 7,146,147 7,115,690 8,837 9,351 12,269 30,457 0.43 Total Loans $ 17,653,757 $ 17,590,442 $ 9,715 $ 11,682 $ 41,918 $ 63,315 0.36 % Delinquency % 99.64% 0.06% 0.07% 0.24% 0.36%
Schedule of Loan Modifications	The following table presents the amortized basis of loans that were modified to borrowers experiencing financial difficulty during the period by loan class and modification type. All such modifications during the quarter were term extensions. Three Months Ended December 31, 2023 Loan Class Term Extension % of Total Loan Class Balance Wtd. Avg. ( in thousands) (in months) Commercial real estate $ 143 — % 20 Commercial & industrial 7,814 0.33 4 Construction 346 0.02 4 Total commercial loans 8,303 0.09 Total Loans $ 8,303 0.05 %
Schedule of Loans Based on Credit Quality Indicators	The following tables present by primary credit quality indicator, loan class, and year of origination, the amortized cost basis of loans receivable as of December 31, 2023 and September 30, 2023. There were no commercial loans classified as Doubtful or Loss as of either date. December 31, 2023 Term Loans Amortized Cost Basis by Origination Year YTD 2024 2023 2022 2021 2020 Prior to 2020 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 10,416 $ 135,720 $ 778,628 $ 955,583 $ 462,169 $ 521,665 $ 35,552 $ 13,959 $ 2,913,692 Special Mention — — 90,668 — — — — — 90,668 Substandard — — 5,690 2,302 2,416 7,689 — — 18,097 Total $ 10,416 $ 135,720 $ 874,986 $ 957,885 $ 464,585 $ 529,354 $ 35,552 $ 13,959 $ 3,022,457 Commercial real estate Pass $ 61,720 $ 204,566 $ 979,199 $ 750,603 $ 444,855 $ 777,833 $ 2,317 $ — $ 3,221,093 Special Mention — — — 784 — — — — 784 Substandard — 499 12,475 2,260 29,908 65,274 — — 110,416 Total $ 61,720 $ 205,065 $ 991,674 $ 753,647 $ 474,763 $ 843,107 $ 2,317 $ — $ 3,332,293 Commercial & industrial Pass $ 13,685 $ 160,759 $ 284,699 $ 310,840 $ 112,799 $ 187,813 $ 1,154,212 $ 55 $ 2,224,862 Special Mention — — — — — — 2,850 — 2,850 Substandard — — 10,457 5,346 2,784 49,992 68,690 1 137,270 Total $ 13,685 $ 160,759 $ 295,156 $ 316,186 $ 115,583 $ 237,805 $ 1,225,752 $ 56 $ 2,364,982 Gross Charge-offs — — — — — 31 — 31 62 Construction Pass $ 16,959 $ 321,724 $ 761,021 $ 396,547 $ 49,865 $ 49,310 $ 79,723 $ — $ 1,675,149 Substandard 396 3,218 3,703 13,040 — — — — 20,357 Total $ 17,355 $ 324,942 $ 764,724 $ 409,587 $ 49,865 $ 49,310 $ 79,723 $ — $ 1,695,506 Land - acquisition & development Pass $ 9,598 $ 18,096 $ 60,988 $ 32,782 $ 6,251 $ 18,258 $ 2,600 $ — $ 148,573 Substandard — — 138 — — — — — 138 Total $ 9,598 $ 18,096 $ 61,126 $ 32,782 $ 6,251 $ 18,258 $ 2,600 $ — $ 148,711 Gross Charge-offs — — — — — 18 — — 18 Total commercial loans Pass $ 112,378 $ 840,865 $ 2,864,535 $ 2,446,355 $ 1,075,939 $ 1,554,879 $ 1,274,404 $ 14,014 $ 10,183,369 Special Mention — — 90,668 784 — — 2,850 — 94,302 Substandard 396 3,717 32,463 22,948 35,108 122,955 68,690 1 286,278 Total $ 112,774 $ 844,582 $ 2,987,666 $ 2,470,087 $ 1,111,047 $ 1,677,834 $ 1,345,944 $ 14,015 $ 10,563,949 Gross Charge-offs $ — $ — $ — $ — $ — $ 49 $ — $ 31 $ 80 December 31, 2023 Term Loans Amortized Cost Basis by Origination Year YTD 2024 2023 2022 2021 2020 Prior to 2020 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 50,755 $ 493,002 $ 1,584,370 $ 1,703,961 $ 715,431 $ 1,925,787 $ — $ — $ 6,473,306 30 days past due — 820 337 1,470 746 2,758 — — 6,131 60 days past due — — 863 1,335 — 1,867 — — 4,065 90+ days past due — 996 469 675 682 9,125 — — 11,947 Total $ 50,755 $ 494,818 $ 1,586,039 $ 1,707,441 $ 716,859 $ 1,939,537 $ — $ — $ 6,495,449 Construction - custom Current $ 1,331 $ 127,150 $ 131,617 $ 1,963 $ 372 $ 358 $ — $ — $ 262,791 30 days past due — — 760 — — — — — 760 90+ days past due — — 87 — — — — — 87 Total $ 1,331 $ 127,150 $ 132,464 $ 1,963 $ 372 $ 358 $ — $ — $ 263,638 Land - consumer lot loans Current $ 3,804 $ 18,850 $ 39,120 $ 29,413 $ 11,342 $ 15,995 $ — $ — $ 118,524 30 days past due — — — 336 — — — — 336 90+ days past due — — — 57 — — — — 57 Total $ 3,804 $ 18,850 $ 39,120 $ 29,806 $ 11,342 $ 15,995 $ — $ — $ 118,917 HELOC Current $ — $ — $ — $ — $ — $ 4,797 $ 240,274 $ 406 $ 245,477 30 days past due — — — — — 531 586 — 1,117 90+ days past due — — — — — 8 543 — 551 Total $ — $ — $ — $ — $ — $ 5,336 $ 241,403 $ 406 $ 247,145 Consumer Current $ 29 $ 139 $ 122 $ 9,648 $ 8,005 $ 21,864 $ 34,521 $ — $ 74,328 30 days past due — — — — — 145 63 — 208 60 days past due — — — — — 4 43 — 47 90+ days past due — — — — — 137 124 — 261 Total $ 29 $ 139 $ 122 $ 9,648 $ 8,005 $ 22,150 $ 34,751 $ — $ 74,844 Gross Charge-offs — — — — — 116 97 — 213 Total consumer loans Current $ 55,919 $ 639,141 $ 1,755,229 $ 1,744,985 $ 735,150 $ 1,968,801 $ 274,795 $ 406 $ 7,174,426 30 days past due — 820 1,097 1,806 746 3,434 649 — 8,552 60 days past due — — 863 1,335 — 1,871 43 — 4,112 90+ days past due — 996 556 732 682 9,270 667 — 12,903 Total $ 55,919 $ 640,957 $ 1,757,745 $ 1,748,858 $ 736,578 $ 1,983,376 $ 276,154 $ 406 $ 7,199,993 Gross Charge-offs $ — $ — $ — $ — $ — $ 116 $ 97 $ — $ 213 September 30, 2023 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior to 2019 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 135,859 $ 658,126 $ 850,998 $ 541,655 $ 135,965 $ 400,412 $ 49,523 $ — $ 2,772,538 Special Mention — 90,428 — — — — — — 90,428 Substandard — 5,711 2,309 2,422 7,583 5,603 — — 23,628 Total $ 135,859 $ 754,265 $ 853,307 $ 544,077 $ 143,548 $ 406,015 $ 49,523 $ — $ 2,886,594 Commercial real estate Pass $ 221,057 $ 912,776 $ 735,069 $ 476,941 $ 262,945 $ 596,459 $ 2,349 $ — $ 3,207,596 Special Mention — — 788 — 4,059 — — — 4,847 Substandard 499 5,361 3,810 24,538 27,916 35,534 — — 97,658 Total $ 221,556 $ 918,137 $ 739,667 $ 501,479 $ 294,920 $ 631,993 $ 2,349 $ — $ 3,310,101 Commercial & industrial Pass $ 155,411 $ 258,798 $ 316,713 $ 117,089 $ 24,246 $ 175,042 $ 1,089,896 $ 27,681 $ 2,164,876 Special Mention — — — — 2,940 — 3,707 — 6,647 Substandard — 5,532 8,537 2,783 3,819 46,297 69,948 6,879 143,795 Total $ 155,411 $ 264,330 $ 325,250 $ 119,872 $ 31,005 $ 221,339 $ 1,163,551 $ 34,560 $ 2,315,318 Construction Pass $ 235,150 $ 833,577 $ 559,850 $ 68,105 $ 46,390 $ 373 $ 74,821 $ — $ 1,818,266 Substandard 2,901 5,119 12,650 — — — — — 20,670 Total $ 238,051 $ 838,696 $ 572,500 $ 68,105 $ 46,390 $ 373 $ 74,821 $ — $ 1,838,936 Land - acquisition & development Pass $ 20,593 $ 69,414 $ 39,276 $ 6,280 $ 351 $ 17,876 $ 2,600 $ — $ 156,390 Substandard — 271 — — — — — — 271 Total $ 20,593 $ 69,685 $ 39,276 $ 6,280 $ 351 $ 17,876 $ 2,600 $ — $ 156,661 Total commercial loans Pass $ 768,070 $ 2,732,691 $ 2,501,906 $ 1,210,070 $ 469,897 $ 1,190,162 $ 1,219,189 $ 27,681 $ 10,119,666 Special Mention — 90,428 788 — 6,999 — 3,707 — 101,922 Substandard 3,400 21,994 27,306 29,743 39,318 87,434 69,948 6,879 286,022 Total $ 771,470 $ 2,845,113 $ 2,530,000 $ 1,239,813 $ 516,214 $ 1,277,596 $ 1,292,844 $ 34,560 $ 10,507,610 September 30, 2023 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior to 2019 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 513,007 $ 1,478,479 $ 1,719,163 $ 718,250 $ 295,836 $ 1,640,330 $ — $ — $ 6,365,065 30 days past due 822 115 859 392 221 4,032 — — 6,441 60 days past due — 1,526 1,420 1,325 — 1,797 — — 6,068 90+ days past due — 1,470 666 1,408 — 7,872 — — 11,416 Total $ 513,829 $ 1,481,590 $ 1,722,108 $ 721,375 $ 296,057 $ 1,654,031 $ — $ — $ 6,388,990 Construction - custom Current $ 92,081 $ 218,988 $ 8,838 $ 243 $ 358 $ 479 $ — $ — $ 320,987 30 days past due — 760 — — — — — — 760 60 days past due — — — 2,617 — — — — 2,617 90+ days past due — 87 — — — — — — 87 Total $ 92,081 $ 219,835 $ 8,838 $ 2,860 $ 358 $ 479 $ — $ — $ 324,451 Land - consumer lot loans Current $ 19,128 $ 41,658 $ 35,048 $ 11,517 $ 4,166 $ 12,714 $ — $ — $ 124,231 30 days past due — — 358 — — — — — 358 60 days past due — — 245 — — — — — 245 90+ days past due — — — — — 8 — — 8 Total $ 19,128 $ 41,658 $ 35,651 $ 11,517 $ 4,166 $ 12,722 $ — $ — $ 124,842 HELOC Current $ — $ — $ — $ — $ — $ 3,733 $ 230,338 $ 1,637 $ 235,708 30 days past due — — — — — 44 1,006 — 1,050 60 days past due — — — — — 314 — — 314 90+ days past due — — — — — — 682 — 682 Total $ — $ — $ — $ — $ — $ 4,091 $ 232,026 $ 1,637 $ 237,754 Consumer Current $ 662 $ 121 $ 9,748 $ 8,006 $ 16 $ 23,201 $ 27,945 $ — $ 69,699 30 days past due — — — — — 225 3 — 228 60 days past due — — — — — 106 1 — 107 90+ days past due — — — — 29 46 — 1 76 Total $ 662 $ 121 $ 9,748 $ 8,006 $ 45 $ 23,578 $ 27,949 $ 1 $ 70,110 Total consumer loans Current $ 624,878 $ 1,739,246 $ 1,772,797 $ 738,016 $ 300,376 $ 1,680,457 $ 258,283 $ 1,637 $ 7,115,690 30 days past due 822 875 1,217 392 221 4,301 1,009 — 8,837 60 days past due — 1,526 1,665 3,942 — 2,217 1 — 9,351 90+ days past due — 1,557 666 1,408 29 7,926 682 1 12,269 Total $ 625,700 $ 1,743,204 $ 1,776,345 $ 743,758 $ 300,626 $ 1,694,901 $ 259,975 $ 1,638 $ 7,146,147 The following tables provide the amortized cost of loans receivable based on risk rating categories as previously defined. December 31, 2023 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,913,692 $ 90,668 $ 18,097 $ — $ — $ 3,022,457 Commercial real estate 3,221,093 784 110,416 — — 3,332,293 Commercial & industrial 2,224,862 2,850 137,270 — — 2,364,982 Construction 1,675,149 — 20,357 — — 1,695,506 Land - acquisition & development 148,573 — 138 — — 148,711 Total commercial loans 10,183,369 94,302 286,278 — — 10,563,949 Consumer loans Single-family residential 6,477,005 — 18,444 — — 6,495,449 Construction - custom 263,550 — 88 — — 263,638 Land - consumer lot loans 118,860 — 57 — — 118,917 HELOC 246,541 — 604 — — 247,145 Consumer 74,708 — 136 — — 74,844 Total consumer loans 7,180,664 — 19,329 — — 7,199,993 Total $ 17,364,033 $ 94,302 $ 305,607 $ — $ — $ 17,763,942 Total grade as a % of total loans 97.75 % 0.53 % 1.72 % — % — % September 30, 2023 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total Gross Loans (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,772,538 $ 90,428 $ 23,628 $ — $ — $ 2,886,594 Commercial real estate 3,207,596 4,847 97,658 — — 3,310,101 Commercial & industrial 2,164,876 6,647 143,795 — — 2,315,318 Construction 1,818,266 — 20,670 — — 1,838,936 Land - acquisition & development 156,390 — 271 — — 156,661 Total commercial loans 10,119,666 101,922 286,022 — — 10,507,610 Consumer loans Single-family residential 6,370,936 — 18,054 — — 6,388,990 Construction - custom 324,363 — 88 — — 324,451 Land - consumer lot loans 124,588 — 254 — — 124,842 HELOC 237,018 — 736 — — 237,754 Consumer 70,098 — 12 — — 70,110 Total consumer loans 7,127,003 — 19,144 — — 7,146,147 Total loans $ 17,246,669 $ 101,922 $ 305,166 $ — $ — $ 17,653,757 Total grade as a % of total gross loans 97.69 % 0.58 % 1.73 % — % — % The following tables provide information on the amortized cost of loans receivable based on borrower payment activity. December 31, 2023 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 3,022,325 100.0 % $ 132 — % Commercial real estate 3,308,010 99.3 24,283 0.7 Commercial & industrial 2,360,545 99.8 4,437 0.2 Construction 1,695,506 100.0 — 0.0 Land - acquisition & development 148,711 100.0 — — Total commercial loans 10,535,097 99.7 28,852 0.3 Consumer loans Single-family residential 6,480,053 99.8 15,396 0.2 Construction - custom 263,550 100.0 88 — Land - consumer lot loans 118,860 100.0 57 0.0 HELOC 246,542 99.8 603 0.2 Consumer 74,582 99.6 262 0.4 Total consumer loans 7,183,587 99.8 16,406 0.2 Total loans $ 17,718,684 99.7 % $ 45,258 0.3 % September 30, 2023 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,881,467 99.8 % $ 5,127 0.2 % Commercial real estate 3,286,666 99.3 23,435 0.7 Commercial & industrial 2,309,236 99.7 6,082 0.3 Construction 1,838,936 100.0 — — Land - acquisition & development 156,661 100.0 — — Total commercial loans 10,472,966 99.7 34,644 0.3 Consumer loans Single-family residential 6,374,072 99.8 14,918 0.2 Construction - custom 324,363 100.0 88 — Land - consumer lot loans 124,833 100.0 9 — HELOC 237,018 99.7 736 0.3 Consumer 70,083 100.0 27 0.0 Total consumer loans 7,130,369 99.8 15,778 0.2 Total loans $ 17,603,335 99.7 % $ 50,422 0.3 %

Allowance for Losses on Loans (

Allowance for Losses on Loans (Tables)	3 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Schedule of Allowance for Credit Losses by Loan Portfolio Segment and Class	The following tables summarize the activity in the allowance for loan losses by loan portfolio segment and class. Three Months Ended December 31, 2023 Beginning Allowance Charge-offs Recoveries Provision & Ending Allowance (In thousands) Commercial loans Multi-family $ 13,155 $ — $ — $ 636 $ 13,791 Commercial real estate 28,842 — 2 163 29,007 Commercial & industrial 58,773 (62) 32 2,093 60,836 Construction 29,408 — — (545) 28,863 Land - acquisition & development 7,016 (18) 50 (390) 6,658 Total commercial loans 137,194 (80) 84 1,957 139,155 Consumer loans Single-family residential 28,029 — 120 407 28,556 Construction - custom 2,781 — — (519) 2,262 Land - consumer lot loans 3,512 — 9 (176) 3,345 HELOC 2,859 — 1 113 2,973 Consumer 2,832 (213) 192 218 3,029 Total consumer loans 40,013 (213) 322 43 40,165 Total ACL - loans $ 177,207 $ (293) $ 406 $ 2,000 $ 179,320 (1) Provision & transfer amounts within the table do not include provision recapture from unfunded commitments of $2,000,000. Three Months Ended December 31, 2022 Beginning Allowance Charge-offs Recoveries Provision & Ending Allowance (In thousands) Commercial loans Multi-family $ 12,013 $ — $ — $ 311 $ 12,324 Commercial real estate 25,814 — 4 1,562 27,380 Commercial & industrial 57,210 (82) 32 6,713 63,873 Construction 26,161 — — (28) 26,133 Land - acquisition & development 12,278 — 16 (3,722) 8,572 Total commercial loans 133,476 (82) 52 4,836 138,282 Consumer loans Single-family residential 25,518 — 430 (473) 25,475 Construction - custom 3,410 — — 90 3,500 Land - consumer lot loans 5,047 — — (905) 4,142 HELOC 2,482 — 1 105 2,588 Consumer 2,875 (146) 234 (153) 2,810 Total consumer loans 39,332 (146) 665 (1,336) 38,515 Total loans $ 172,808 $ (228) $ 717 $ 3,500 $ 176,797 (1) Provision & transfer amounts within the table do not include provision recapture from unfunded commitments of $1,000,000
Schedule of Loans Based on Credit Quality Indicators	The following tables present by primary credit quality indicator, loan class, and year of origination, the amortized cost basis of loans receivable as of December 31, 2023 and September 30, 2023. There were no commercial loans classified as Doubtful or Loss as of either date. December 31, 2023 Term Loans Amortized Cost Basis by Origination Year YTD 2024 2023 2022 2021 2020 Prior to 2020 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 10,416 $ 135,720 $ 778,628 $ 955,583 $ 462,169 $ 521,665 $ 35,552 $ 13,959 $ 2,913,692 Special Mention — — 90,668 — — — — — 90,668 Substandard — — 5,690 2,302 2,416 7,689 — — 18,097 Total $ 10,416 $ 135,720 $ 874,986 $ 957,885 $ 464,585 $ 529,354 $ 35,552 $ 13,959 $ 3,022,457 Commercial real estate Pass $ 61,720 $ 204,566 $ 979,199 $ 750,603 $ 444,855 $ 777,833 $ 2,317 $ — $ 3,221,093 Special Mention — — — 784 — — — — 784 Substandard — 499 12,475 2,260 29,908 65,274 — — 110,416 Total $ 61,720 $ 205,065 $ 991,674 $ 753,647 $ 474,763 $ 843,107 $ 2,317 $ — $ 3,332,293 Commercial & industrial Pass $ 13,685 $ 160,759 $ 284,699 $ 310,840 $ 112,799 $ 187,813 $ 1,154,212 $ 55 $ 2,224,862 Special Mention — — — — — — 2,850 — 2,850 Substandard — — 10,457 5,346 2,784 49,992 68,690 1 137,270 Total $ 13,685 $ 160,759 $ 295,156 $ 316,186 $ 115,583 $ 237,805 $ 1,225,752 $ 56 $ 2,364,982 Gross Charge-offs — — — — — 31 — 31 62 Construction Pass $ 16,959 $ 321,724 $ 761,021 $ 396,547 $ 49,865 $ 49,310 $ 79,723 $ — $ 1,675,149 Substandard 396 3,218 3,703 13,040 — — — — 20,357 Total $ 17,355 $ 324,942 $ 764,724 $ 409,587 $ 49,865 $ 49,310 $ 79,723 $ — $ 1,695,506 Land - acquisition & development Pass $ 9,598 $ 18,096 $ 60,988 $ 32,782 $ 6,251 $ 18,258 $ 2,600 $ — $ 148,573 Substandard — — 138 — — — — — 138 Total $ 9,598 $ 18,096 $ 61,126 $ 32,782 $ 6,251 $ 18,258 $ 2,600 $ — $ 148,711 Gross Charge-offs — — — — — 18 — — 18 Total commercial loans Pass $ 112,378 $ 840,865 $ 2,864,535 $ 2,446,355 $ 1,075,939 $ 1,554,879 $ 1,274,404 $ 14,014 $ 10,183,369 Special Mention — — 90,668 784 — — 2,850 — 94,302 Substandard 396 3,717 32,463 22,948 35,108 122,955 68,690 1 286,278 Total $ 112,774 $ 844,582 $ 2,987,666 $ 2,470,087 $ 1,111,047 $ 1,677,834 $ 1,345,944 $ 14,015 $ 10,563,949 Gross Charge-offs $ — $ — $ — $ — $ — $ 49 $ — $ 31 $ 80 December 31, 2023 Term Loans Amortized Cost Basis by Origination Year YTD 2024 2023 2022 2021 2020 Prior to 2020 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 50,755 $ 493,002 $ 1,584,370 $ 1,703,961 $ 715,431 $ 1,925,787 $ — $ — $ 6,473,306 30 days past due — 820 337 1,470 746 2,758 — — 6,131 60 days past due — — 863 1,335 — 1,867 — — 4,065 90+ days past due — 996 469 675 682 9,125 — — 11,947 Total $ 50,755 $ 494,818 $ 1,586,039 $ 1,707,441 $ 716,859 $ 1,939,537 $ — $ — $ 6,495,449 Construction - custom Current $ 1,331 $ 127,150 $ 131,617 $ 1,963 $ 372 $ 358 $ — $ — $ 262,791 30 days past due — — 760 — — — — — 760 90+ days past due — — 87 — — — — — 87 Total $ 1,331 $ 127,150 $ 132,464 $ 1,963 $ 372 $ 358 $ — $ — $ 263,638 Land - consumer lot loans Current $ 3,804 $ 18,850 $ 39,120 $ 29,413 $ 11,342 $ 15,995 $ — $ — $ 118,524 30 days past due — — — 336 — — — — 336 90+ days past due — — — 57 — — — — 57 Total $ 3,804 $ 18,850 $ 39,120 $ 29,806 $ 11,342 $ 15,995 $ — $ — $ 118,917 HELOC Current $ — $ — $ — $ — $ — $ 4,797 $ 240,274 $ 406 $ 245,477 30 days past due — — — — — 531 586 — 1,117 90+ days past due — — — — — 8 543 — 551 Total $ — $ — $ — $ — $ — $ 5,336 $ 241,403 $ 406 $ 247,145 Consumer Current $ 29 $ 139 $ 122 $ 9,648 $ 8,005 $ 21,864 $ 34,521 $ — $ 74,328 30 days past due — — — — — 145 63 — 208 60 days past due — — — — — 4 43 — 47 90+ days past due — — — — — 137 124 — 261 Total $ 29 $ 139 $ 122 $ 9,648 $ 8,005 $ 22,150 $ 34,751 $ — $ 74,844 Gross Charge-offs — — — — — 116 97 — 213 Total consumer loans Current $ 55,919 $ 639,141 $ 1,755,229 $ 1,744,985 $ 735,150 $ 1,968,801 $ 274,795 $ 406 $ 7,174,426 30 days past due — 820 1,097 1,806 746 3,434 649 — 8,552 60 days past due — — 863 1,335 — 1,871 43 — 4,112 90+ days past due — 996 556 732 682 9,270 667 — 12,903 Total $ 55,919 $ 640,957 $ 1,757,745 $ 1,748,858 $ 736,578 $ 1,983,376 $ 276,154 $ 406 $ 7,199,993 Gross Charge-offs $ — $ — $ — $ — $ — $ 116 $ 97 $ — $ 213 September 30, 2023 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior to 2019 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 135,859 $ 658,126 $ 850,998 $ 541,655 $ 135,965 $ 400,412 $ 49,523 $ — $ 2,772,538 Special Mention — 90,428 — — — — — — 90,428 Substandard — 5,711 2,309 2,422 7,583 5,603 — — 23,628 Total $ 135,859 $ 754,265 $ 853,307 $ 544,077 $ 143,548 $ 406,015 $ 49,523 $ — $ 2,886,594 Commercial real estate Pass $ 221,057 $ 912,776 $ 735,069 $ 476,941 $ 262,945 $ 596,459 $ 2,349 $ — $ 3,207,596 Special Mention — — 788 — 4,059 — — — 4,847 Substandard 499 5,361 3,810 24,538 27,916 35,534 — — 97,658 Total $ 221,556 $ 918,137 $ 739,667 $ 501,479 $ 294,920 $ 631,993 $ 2,349 $ — $ 3,310,101 Commercial & industrial Pass $ 155,411 $ 258,798 $ 316,713 $ 117,089 $ 24,246 $ 175,042 $ 1,089,896 $ 27,681 $ 2,164,876 Special Mention — — — — 2,940 — 3,707 — 6,647 Substandard — 5,532 8,537 2,783 3,819 46,297 69,948 6,879 143,795 Total $ 155,411 $ 264,330 $ 325,250 $ 119,872 $ 31,005 $ 221,339 $ 1,163,551 $ 34,560 $ 2,315,318 Construction Pass $ 235,150 $ 833,577 $ 559,850 $ 68,105 $ 46,390 $ 373 $ 74,821 $ — $ 1,818,266 Substandard 2,901 5,119 12,650 — — — — — 20,670 Total $ 238,051 $ 838,696 $ 572,500 $ 68,105 $ 46,390 $ 373 $ 74,821 $ — $ 1,838,936 Land - acquisition & development Pass $ 20,593 $ 69,414 $ 39,276 $ 6,280 $ 351 $ 17,876 $ 2,600 $ — $ 156,390 Substandard — 271 — — — — — — 271 Total $ 20,593 $ 69,685 $ 39,276 $ 6,280 $ 351 $ 17,876 $ 2,600 $ — $ 156,661 Total commercial loans Pass $ 768,070 $ 2,732,691 $ 2,501,906 $ 1,210,070 $ 469,897 $ 1,190,162 $ 1,219,189 $ 27,681 $ 10,119,666 Special Mention — 90,428 788 — 6,999 — 3,707 — 101,922 Substandard 3,400 21,994 27,306 29,743 39,318 87,434 69,948 6,879 286,022 Total $ 771,470 $ 2,845,113 $ 2,530,000 $ 1,239,813 $ 516,214 $ 1,277,596 $ 1,292,844 $ 34,560 $ 10,507,610 September 30, 2023 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior to 2019 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 513,007 $ 1,478,479 $ 1,719,163 $ 718,250 $ 295,836 $ 1,640,330 $ — $ — $ 6,365,065 30 days past due 822 115 859 392 221 4,032 — — 6,441 60 days past due — 1,526 1,420 1,325 — 1,797 — — 6,068 90+ days past due — 1,470 666 1,408 — 7,872 — — 11,416 Total $ 513,829 $ 1,481,590 $ 1,722,108 $ 721,375 $ 296,057 $ 1,654,031 $ — $ — $ 6,388,990 Construction - custom Current $ 92,081 $ 218,988 $ 8,838 $ 243 $ 358 $ 479 $ — $ — $ 320,987 30 days past due — 760 — — — — — — 760 60 days past due — — — 2,617 — — — — 2,617 90+ days past due — 87 — — — — — — 87 Total $ 92,081 $ 219,835 $ 8,838 $ 2,860 $ 358 $ 479 $ — $ — $ 324,451 Land - consumer lot loans Current $ 19,128 $ 41,658 $ 35,048 $ 11,517 $ 4,166 $ 12,714 $ — $ — $ 124,231 30 days past due — — 358 — — — — — 358 60 days past due — — 245 — — — — — 245 90+ days past due — — — — — 8 — — 8 Total $ 19,128 $ 41,658 $ 35,651 $ 11,517 $ 4,166 $ 12,722 $ — $ — $ 124,842 HELOC Current $ — $ — $ — $ — $ — $ 3,733 $ 230,338 $ 1,637 $ 235,708 30 days past due — — — — — 44 1,006 — 1,050 60 days past due — — — — — 314 — — 314 90+ days past due — — — — — — 682 — 682 Total $ — $ — $ — $ — $ — $ 4,091 $ 232,026 $ 1,637 $ 237,754 Consumer Current $ 662 $ 121 $ 9,748 $ 8,006 $ 16 $ 23,201 $ 27,945 $ — $ 69,699 30 days past due — — — — — 225 3 — 228 60 days past due — — — — — 106 1 — 107 90+ days past due — — — — 29 46 — 1 76 Total $ 662 $ 121 $ 9,748 $ 8,006 $ 45 $ 23,578 $ 27,949 $ 1 $ 70,110 Total consumer loans Current $ 624,878 $ 1,739,246 $ 1,772,797 $ 738,016 $ 300,376 $ 1,680,457 $ 258,283 $ 1,637 $ 7,115,690 30 days past due 822 875 1,217 392 221 4,301 1,009 — 8,837 60 days past due — 1,526 1,665 3,942 — 2,217 1 — 9,351 90+ days past due — 1,557 666 1,408 29 7,926 682 1 12,269 Total $ 625,700 $ 1,743,204 $ 1,776,345 $ 743,758 $ 300,626 $ 1,694,901 $ 259,975 $ 1,638 $ 7,146,147 The following tables provide the amortized cost of loans receivable based on risk rating categories as previously defined. December 31, 2023 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,913,692 $ 90,668 $ 18,097 $ — $ — $ 3,022,457 Commercial real estate 3,221,093 784 110,416 — — 3,332,293 Commercial & industrial 2,224,862 2,850 137,270 — — 2,364,982 Construction 1,675,149 — 20,357 — — 1,695,506 Land - acquisition & development 148,573 — 138 — — 148,711 Total commercial loans 10,183,369 94,302 286,278 — — 10,563,949 Consumer loans Single-family residential 6,477,005 — 18,444 — — 6,495,449 Construction - custom 263,550 — 88 — — 263,638 Land - consumer lot loans 118,860 — 57 — — 118,917 HELOC 246,541 — 604 — — 247,145 Consumer 74,708 — 136 — — 74,844 Total consumer loans 7,180,664 — 19,329 — — 7,199,993 Total $ 17,364,033 $ 94,302 $ 305,607 $ — $ — $ 17,763,942 Total grade as a % of total loans 97.75 % 0.53 % 1.72 % — % — % September 30, 2023 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total Gross Loans (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,772,538 $ 90,428 $ 23,628 $ — $ — $ 2,886,594 Commercial real estate 3,207,596 4,847 97,658 — — 3,310,101 Commercial & industrial 2,164,876 6,647 143,795 — — 2,315,318 Construction 1,818,266 — 20,670 — — 1,838,936 Land - acquisition & development 156,390 — 271 — — 156,661 Total commercial loans 10,119,666 101,922 286,022 — — 10,507,610 Consumer loans Single-family residential 6,370,936 — 18,054 — — 6,388,990 Construction - custom 324,363 — 88 — — 324,451 Land - consumer lot loans 124,588 — 254 — — 124,842 HELOC 237,018 — 736 — — 237,754 Consumer 70,098 — 12 — — 70,110 Total consumer loans 7,127,003 — 19,144 — — 7,146,147 Total loans $ 17,246,669 $ 101,922 $ 305,166 $ — $ — $ 17,653,757 Total grade as a % of total gross loans 97.69 % 0.58 % 1.73 % — % — % The following tables provide information on the amortized cost of loans receivable based on borrower payment activity. December 31, 2023 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 3,022,325 100.0 % $ 132 — % Commercial real estate 3,308,010 99.3 24,283 0.7 Commercial & industrial 2,360,545 99.8 4,437 0.2 Construction 1,695,506 100.0 — 0.0 Land - acquisition & development 148,711 100.0 — — Total commercial loans 10,535,097 99.7 28,852 0.3 Consumer loans Single-family residential 6,480,053 99.8 15,396 0.2 Construction - custom 263,550 100.0 88 — Land - consumer lot loans 118,860 100.0 57 0.0 HELOC 246,542 99.8 603 0.2 Consumer 74,582 99.6 262 0.4 Total consumer loans 7,183,587 99.8 16,406 0.2 Total loans $ 17,718,684 99.7 % $ 45,258 0.3 % September 30, 2023 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,881,467 99.8 % $ 5,127 0.2 % Commercial real estate 3,286,666 99.3 23,435 0.7 Commercial & industrial 2,309,236 99.7 6,082 0.3 Construction 1,838,936 100.0 — — Land - acquisition & development 156,661 100.0 — — Total commercial loans 10,472,966 99.7 34,644 0.3 Consumer loans Single-family residential 6,374,072 99.8 14,918 0.2 Construction - custom 324,363 100.0 88 — Land - consumer lot loans 124,833 100.0 9 — HELOC 237,018 99.7 736 0.3 Consumer 70,083 100.0 27 0.0 Total consumer loans 7,130,369 99.8 15,778 0.2 Total loans $ 17,603,335 99.7 % $ 50,422 0.3 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets Measured on Recurring Basis	The following tables present the balance and level in the fair value hierarchy of assets and liabilities that are measured at fair value on a recurring basis (with the exception of those measured using the NAV practical expedient). December 31, 2023 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 232,359 $ — $ 232,359 Asset-backed securities — 561,304 — 561,304 Municipal bonds — 35,206 — 35,206 Corporate debt securities — 248,813 — 248,813 Mortgage-backed securities Agency pass-through certificates — 940,763 — 940,763 Total available-for-sale securities — 2,018,445 — 2,018,445 Client swap program hedges — 55,631 — 55,631 Commercial loan fair value hedges — 2,061 — 2,061 Mortgage loan fair value hedges — 22,244 — 22,244 Borrowings cash flow hedges — 143,846 — 143,846 Total financial assets $ — $ 2,242,227 $ — $ 2,242,227 Financial Liabilities Client swap program hedges $ — $ 56,392 $ — $ 56,392 Total financial liabilities $ — $ 56,392 $ — $ 56,392 September 30, 2023 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 217,053 $ — $ 217,053 Asset-backed securities — 588,016 588,016 Municipal bonds — 34,662 — 34,662 Corporate debt securities — 242,522 — 242,522 Mortgage-backed securities Agency pass-through certificates — 912,844 — 912,844 Total available-for-sale securities — 1,995,097 — 1,995,097 Client swap program hedges — 78,797 — 78,797 Commercial loan fair value hedges — 3,405 — 3,405 Mortgage loan fair value hedges — 46,396 — 46,396 Borrowings cash flow hedges — 184,373 — 184,373 Total financial assets $ — $ 2,308,068 $ — $ 2,308,068 Financial Liabilities Client swap program hedges $ — $ 79,668 $ — $ 79,668 Total financial liabilities $ — $ 79,668 $ — $ 79,668
Schedule of Fair Value of Assets Measured on Nonrecurring Basis	The following tables present the aggregated balance of assets that were measured at fair value on a nonrecurring basis at December 31, 2023 and December 31, 2022, and the total gains (losses) resulting from those fair value adjustments during the respective periods. The estimated fair value measurements are shown gross of estimated selling costs. December 31, 2023 Three Months Ended December 31, 2023 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ 781 $ 781 $ (158) Real estate owned (2) — — — — — Balance at end of period $ — $ — $ 781 $ 781 $ (158) (1) The gains (losses) represent re-measurements of collateral-dependent loans. (2) The gains (losses) represent aggregate write-downs and charge-offs on real estate owned. December 31, 2022 Three Months Ended December 31, 2022 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ — $ — $ (123) Real estate owned (2) — — — — — Balance at end of period $ — $ — $ — $ — $ (123) (1) The gains (losses) represent re-measurements of collateral-dependent loans. (2) The gains (losses) represent aggregate write-downs and charge-offs on real estate owned.
Schedule of Fair Value of Financial Instruments by Balance Sheet Grouping	Although management is not aware of any factors that would materially affect the estimated fair value amounts presented below, such amounts have not been comprehensively revalued for purposes of these financial statements since the dates shown, and therefore, estimates of fair value subsequent to those dates may differ significantly from the amounts presented below. December 31, 2023 September 30, 2023 Level in Fair Value Hierarchy Carrying Estimated Carrying Estimated ($ in thousands) Financial assets Cash and cash equivalents 1 $ 1,144,774 $ 1,144,774 $ 980,649 $ 980,649 Available-for-sale securities U.S. government and agency securities 2 232,359 232,359 217,053 217,053 Asset-backed securities 2 561,304 561,304 588,016 588,016 Municipal bonds 2 35,206 35,206 34,662 34,662 Corporate debt securities 2 248,813 248,813 242,522 242,522 Mortgage-backed securities Agency pass-through certificates 2 940,763 940,763 912,844 912,844 Total available-for-sale securities 2,018,445 2,018,445 1,995,097 1,995,097 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 2 415,079 370,942 423,586 355,188 Total held-to-maturity securities 415,079 370,942 423,586 355,188 Loans receivable 3 17,584,622 16,876,965 17,476,550 16,559,758 FHLB stock 2 137,940 137,940 126,820 126,820 Other assets - client swap program hedges 2 55,631 55,631 78,797 78,797 Other assets - commercial fair value loan hedges 2 2,061 2,061 3,405 3,405 Other assets - mortgage loan fair value hedges 2 22,244 22,244 46,396 46,396 Other assets - borrowings cash flow hedges 2 143,846 143,846 184,373 184,373 Financial liabilities Time deposits 2 5,380,723 5,363,731 5,305,016 5,232,689 Borrowings 2 3,875,000 3,867,812 3,650,000 3,653,229 Other liabilities - client swap program hedges 2 56,392 56,392 79,668 79,668
Schedule of Reconciliation of Amortized Cost to Fair Value of Available-for-Sale and Held-to-Maturity Securities	The following tables provide details about the amortized cost and fair value of available-for-sale and held-to-maturity securities. December 31, 2023 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due Within 1 year $ 1,750 $ — $ (5) $ 1,745 6.07 % 1 to 5 years 16,747 8 (305) 16,450 4.54 % 5 to 10 years 110,295 189 (173) 110,311 6.01 Over 10 years 103,594 267 (8) 103,853 6.09 Asset-backed securities 1 to 5 years 17,693 — (766) 16,927 6.08 5 to 10 years 31,469 14 (205) 31,278 6.23 Over 10 years 519,103 316 (6,320) 513,099 6.37 Corporate debt securities due 1 to 5 years 152,022 479 (1,196) 151,305 5.15 5 to 10 years 112,923 — (15,415) 97,508 3.87 Municipal bonds due 5 to 10 years 5,712 — (298) 5,414 3.00 Over 10 years 29,822 95 (125) 29,792 5.85 Mortgage-backed securities Agency pass-through certificates 1,000,184 707 (60,128) 940,763 3.44 2,101,314 2,075 (84,944) 2,018,445 4.69 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 415,079 27 (44,164) 370,942 2.88 415,079 27 (44,164) 370,942 2.88 $ 2,516,393 $ 2,102 $ (129,108) $ 2,389,387 4.39 % September 30, 2023 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due Within 1 year $ 3,501 $ — $ (36) $ 3,465 6.06 % 1 to 5 years 18,894 — (563) 18,331 4.70 % 5 to 10 years 87,922 177 — 88,099 5.76 Over 10 years 106,340 831 (13) 107,158 5.84 Asset-backed securities 1 to 5 years 18,579 — (715) 17,864 6.06 5 to 10 years 36,875 2 (99) 36,778 6.11 Over 10 years 539,911 578 (7,115) 533,374 6.35 Corporate debt securities due 1 to 5 years 151,893 895 (1,787) 151,001 5.14 5 to 10 years 113,221 — (21,700) 91,521 3.87 Municipal bonds due 5 to 10 years 5,720 — (701) 5,019 3.00 Over 10 years 29,832 361 (550) 29,643 5.85 Mortgage-backed securities Agency pass-through certificates 1,005,928 66 (93,150) 912,844 3.39 2,118,616 2,910 (126,429) 1,995,097 4.64 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 423,586 — (68,398) 355,188 2.88 423,586 — (68,398) 355,188 2.88 $ 2,542,202 $ 2,910 $ (194,827) $ 2,350,285 4.35 %
Schedule of Debt Securities, Available-for-Sale	The following tables show the gross unrealized losses and fair value of securities as of December 31, 2023 and September 30, 2023, by length of time that individual securities in each category have been in a continuous loss position. There were 220 and 231 securities with an unrealized loss as of December 31, 2023 and September 30, 2023, respectively. December 31, 2023 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Corporate debt securities $ — $ — $ (16,611) $ 174,074 $ (16,611) $ 174,074 Municipal bonds — — (423) 15,111 (423) 15,111 U.S. government and agency securities (181) 134,687 (310) 13,720 (491) 148,407 Asset-backed securities — — (7,291) 522,583 (7,291) 522,583 Mortgage-backed securities (72) 18,243 (60,056) 756,173 (60,128) 774,416 (253) 152,930 (84,691) 1,481,661 (84,944) 1,634,591 Held-to-maturity securities Mortgage-backed securities — — (44,164) 369,265 (44,164) 369,265 $ (253) $ 152,930 $ (128,855) $ 1,850,926 $ (129,108) $ 2,003,856 September 30, 2023 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Corporate debt securities $ — $ — $ (23,487) $ 167,452 $ (23,487) $ 167,452 Municipal bonds due — — (1,250) 14,302 (1,250) 14,302 U.S. government and agency securities (13) 14,917 (599) 21,795 (612) 36,712 Asset-backed securities (2,142) 86,800 (5,788) 445,454 (7,930) 532,254 Mortgage-backed securities (2,030) 142,235 (91,120) 744,010 (93,150) 886,245 (4,185) 243,952 (122,244) 1,393,013 (126,429) 1,636,965 Held-to-maturity securities Mortgage-backed securities (15) 1,424 (68,383) 353,764 (68,398) 355,188 $ (4,200) $ 245,376 $ (190,627) $ 1,746,777 $ (194,827) $ 1,992,153

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	3 Months Ended
	Dec. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Fair Value, Notional Amount and Balance Sheet Classification	The following tables present the fair value, notional amount and balance sheet classification of derivative assets and liabilities at December 31, 2023 and September 30, 2023. December 31, 2023 Derivative Assets Derivative Liabilities Interest rate contract purpose Balance Sheet Location Notional Fair Value Balance Sheet Location Notional Fair Value (In thousands) (In thousands) Client swap program hedges Other assets $ 896,485 $ 55,631 Other liabilities $ 896,485 $ 56,392 Commercial loan fair value hedges Other assets 37,042 2,061 Other liabilities — — Mortgage loan fair value hedges Other assets 970,000 22,244 Other liabilities — — Borrowings cash flow hedges Other assets 1,000,000 143,846 Other liabilities — — $ 2,903,527 $ 223,782 $ 896,485 $ 56,392 September 30, 2023 Derivative Assets Derivative Liabilities Interest rate contract purpose Balance Sheet Location Notional Fair Value Balance Sheet Location Notional Fair Value (In thousands) (In thousands) Client swap program hedges Other assets $ 806,744 $ 78,797 Other liabilities $ 806,744 $ 79,668 Commercial loan fair value hedges Other assets 39,661 3,405 Other liabilities — — Mortgage loan fair value hedges Other assets 670,000 46,396 Other liabilities — — Borrowings cash flow hedges Other assets 1,000,000 184,373 Other liabilities — — $ 2,516,405 $ 312,971 $ 806,744 $ 79,668
Schedule of Fair Value Hedge Accounting on Carrying Value of Hedged Items	The following tables present the impact of fair value hedge accounting on the carrying value of the hedged items at December 31, 2023 and September 30, 2023. (In thousands) December 31, 2023 Balance sheet line item in which hedged item is recorded Carrying value of hedged items Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items Loans receivable (1) (2) $ 6,246,208 $ (23,255) $ 6,246,208 $ (23,255) (1) Includes the amortized cost basis of the closed mortgage loan portfolios used to designate the hedging relationships in which the hedged items are a portfolio layer expected to be remaining at the end of the hedging relationships. At December 31, 2023, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $6,211,195,000, the cumulative basis adjustment associated with the hedging relationships was $(21,277,000), and the amount of the designated hedged items was $970,000,000. (2) Includes the amortized cost basis of commercial loans designated in fair value hedging relationships. At December 31, 2023, the amortized cost basis of the hedged commercial loans was $35,013,000 and the cumulative basis adjustment associated with the hedging relationships was $(1,978,000). (In thousands) September 30, 2023 Balance sheet line item in which hedged item is recorded Carrying value of hedged items Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items Loans receivable (1) (2) $ 1,816,870 $ (48,865) $ 1,816,870 $ (48,865) (1) Includes the amortized cost basis of the closed mortgage loan portfolios used to designate the hedging relationships in which the hedged items are the last layer expected to be remaining at the end of the hedging relationships. At September 30, 2023, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $1,780,503,000, the cumulative basis adjustment associated with the hedging relationships was $(45,622,000), and the amount of the designated hedged items was $670,000,000.
Schedule of Impact of Derivative Instruments	The following table presents the impact of derivative instruments (cash flow hedges on borrowings) on AOCI for the periods presented. (In thousands) Three Months Ended December 31, Amount of gain/(loss) recognized in AOCI on derivatives in cash flow hedging relationships 2023 2022 Interest rate contracts: Pay fixed/receive floating swaps on borrowings cash flow hedges $ (40,527) $ (6,806) Total pre-tax gain/(loss) recognized in AOCI $ (40,527) $ (6,806) The following tables present the impact of derivative instruments (client swap program) that are not designated in accounting hedges under ASC 815 for the periods presented. (In thousands) Three Months Ended December 31, Derivative instruments Classification of gain/(loss) recognized in income on derivative instrument 2023 2022 Interest rate contracts: Pay fixed/receive floating swap Other noninterest income $ (28,709) $ (3,878) Receive fixed/pay floating swap Other noninterest income 28,818 3,878 $ 109 $ —
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location	The following tables present the gain (loss) on derivative instruments in fair value and cash flow accounting hedging relationships under ASC 815 for the periods presented. Three Months Ended December 31, 2023 Three Months Ended December 31, 2022 Interest income on loans receivable Interest expense on FHLB advances Interest income on loans receivable Interest expense on FHLB advances (In thousands) (In thousands) Interest income/(expense), including the effects of fair value and cash flow hedges $ 245,792 $ (37,938) $ 203,946 $ (18,974) Gain/(loss) on fair value hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 5,493 $ 3,167 Recognized on derivatives (25,496) (2,849) Recognized on hedged items 25,610 3,132 Net income/(expense) recognized on fair value hedges $ 5,607 $ 3,450 Gain/(loss) on cash flow hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 11,847 $ 7,274 Amount of derivative gain/(loss) reclassified from AOCI into interest income/expense — — Net income/(expense) recognized on cash flow hedges $ 11,847 $ 7,274

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands		3 Months Ended
	Feb. 08, 2021 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) portfolioSegment classOfPortfolioSegment branch	Sep. 30, 2023 USD ($)
Accounting Policies [Line Items]
Number of bank branches | branch		198
Dividend rate	4.875%
Proceeds from issuance of preferred stock, net	$ 293,325
Cash collateral		$ 229,100	$ 326,750
Fair value of NAV		36,708
Remaining unfunded commitment		$ 5,578
Number of portfolio segments for loans held for investment | portfolioSegment		2
Number of classes disaggregating the commercial loan portfolio | classOfPortfolioSegment		5
Number of classes disaggregating the consumer loan portfolio | classOfPortfolioSegment		5
Loans in process		$ 1,516,522	1,895,940
Financing Receivable
Accounting Policies [Line Items]
Loans in process		$ 3,180,001	$ 3,625,333
Public Offering
Accounting Policies [Line Items]
Number of depositary shares | shares	12,000,000
Percentage of preferred stock	2.50%
Public offering price (in usd per share) | $ / shares	$ 25
Series A Preferred Stock | Public Offering
Accounting Policies [Line Items]
Number of depositary shares | shares	300,000

Dividends and Share Repurchas_2

Dividends and Share Repurchases (Details) - $ / shares				3 Months Ended
	Jan. 15, 2024	Dec. 08, 2023	Oct. 15, 2023	Dec. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Cash dividends per share (in dollars per share)		$ 0.25		$ 0.25	$ 0.24
Stock repurchased (in shares)				697,893
Average cost per share (in dollars per share)				$ 24.45
Remaining shares authorized to be repurchased (in shares)				1,861,290
Preferred stock dividends declared (in dollars per share)			$ 12.1875
Depository dividends declared (in dollars per share)			$ 0.30468750
Subsequent Event
Class of Stock [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 12.1875
Depository dividends declared (in dollars per share)	$ 0.30468750

Loans Receivable - Narrative (D

Loans Receivable - Narrative (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2023 USD ($) portfolioSegment loan	Sep. 30, 2023 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of portfolio segments for loans held for investment | portfolioSegment	2
Accrued interest receivables for loans	$ 77,760	$ 77,349
Loans pledged to secure borrowings from the Federal Home Loan Bank	10,493,301	$ 8,941,201
Nonaccrual interest income recognized	511
Impaired, interest income on accrual accrual and performed loans	$ 625
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans modified, past due | loan	1
Commercial loans | Commercial & industrial | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan modified, accumulated amortized cost	$ 1,659

Loans Receivable - Schedule of

Loans Receivable - Schedule of Loans Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 19,353,053	$ 19,648,504
Ratio of loan type to all loans	100%	100%
Allowance for credit losses on loans	$ 179,320	$ 177,207	$ 176,797	$ 172,808
Loans in process	1,516,522	1,895,940
Net deferred fees, costs and discounts	72,589	98,807
Total loan contra accounts	1,768,431	2,171,954
Net loans	17,584,622	17,476,550
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 11,835,871	$ 12,094,294
Ratio of loan type to all loans	61.20%	61.60%
Allowance for credit losses on loans	$ 139,155	$ 137,194	138,282	133,476
Commercial loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 3,054,426	$ 2,907,086
Ratio of loan type to all loans	15.80%	14.80%
Allowance for credit losses on loans	$ 13,791	$ 13,155	12,324	12,013
Commercial loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 3,351,113	$ 3,344,959
Ratio of loan type to all loans	17.30%	17%
Allowance for credit losses on loans	$ 29,007	$ 28,842	27,380	25,814
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 2,371,393	$ 2,321,717
Ratio of loan type to all loans	12.30%	11.80%
Allowance for credit losses on loans	$ 60,836	$ 58,773	63,873	57,210
Commercial loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 2,868,207	$ 3,318,994
Ratio of loan type to all loans	14.80%	16.90%
Allowance for credit losses on loans	$ 28,863	$ 29,408	26,133	26,161
Commercial loans | Land - acquisition & development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 190,732	$ 201,538
Ratio of loan type to all loans	1%	1%
Allowance for credit losses on loans	$ 6,658	$ 7,016	8,572	12,278
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 7,517,182	$ 7,554,210
Ratio of loan type to all loans	38.80%	38.40%
Allowance for credit losses on loans	$ 40,165	$ 40,013	38,515	39,332
Consumer loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 543,748	$ 672,643
Ratio of loan type to all loans	2.80%	3.40%
Allowance for credit losses on loans	$ 2,262	$ 2,781	3,500	3,410
Consumer loans | Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 6,535,073	$ 6,451,270
Ratio of loan type to all loans	33.80%	32.80%
Allowance for credit losses on loans	$ 28,556	$ 28,029	25,475	25,518
Consumer loans | Land - consumer lot loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 119,735	$ 125,723
Ratio of loan type to all loans	0.60%	0.60%
Allowance for credit losses on loans	$ 3,345	$ 3,512	4,142	5,047
Consumer loans | HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 243,742	$ 234,410
Ratio of loan type to all loans	1.20%	1.20%
Allowance for credit losses on loans	$ 2,973	$ 2,859	2,588	2,482
Consumer loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 74,884	$ 70,164
Ratio of loan type to all loans	0.40%	0.40%
Allowance for credit losses on loans	$ 3,029	$ 2,832	$ 2,810	$ 2,875

Loans Receivable - Non-accrual

Loans Receivable - Non-accrual Loans and Loans 90 Days or More Past Due and Accruing (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual percent of total loans	0.25%	0.29%
Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 45,258	$ 50,422
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	28,852	34,644
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Commercial loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	132	5,127
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Commercial loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	24,283	23,435
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	4,437	6,082
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Commercial loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	0	0
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Commercial loans | Land - acquisition & development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	0	0
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	16,406	15,778
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Consumer loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	88	88
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Consumer loans | Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	15,396	14,918
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Consumer loans | Land - consumer lot loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	57	9
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Consumer loans | HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	603	736
Non-accrual with no ACL	0	0
90 days or more past due and accruing	0	0
Financial Asset Originated | Consumer loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	262	27
Non-accrual with no ACL	0	0
90 days or more past due and accruing	$ 0	$ 0

Loans Receivable - Loan Delinqu

Loans Receivable - Loan Delinquencies by Loan Portfolio and Class (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 17,763,942	$ 17,653,757
% based on $, past due	0.33%	0.36%
Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 17,705,885	$ 17,590,442
% based on $, current	99.67%	99.64%
Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 58,057	$ 63,315
% based on $, past due	0.33%	0.36%
30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 12,172	$ 9,715
% based on $, past due	0.07%	0.06%
60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 4,132	$ 11,682
% based on $, past due	0.01%	0.07%
90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 41,753	$ 41,918
% based on $, past due	0.24%	0.24%
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 10,563,949	$ 10,507,610
% based on $, past due	0.31%	0.31%
Commercial loans | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 10,531,459	$ 10,474,752
Commercial loans | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	32,490	32,858
Commercial loans | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	3,620	878
Commercial loans | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	20	2,331
Commercial loans | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	28,850	29,649
Commercial loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 3,022,457	$ 2,886,594
% based on $, past due	0%	0%
Commercial loans | Multi-family | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 3,022,325	$ 2,886,462
Commercial loans | Multi-family | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	132	132
Commercial loans | Multi-family | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Multi-family | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Multi-family | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	132	132
Commercial loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 3,332,293	$ 3,310,101
% based on $, past due	0.76%	0.74%
Commercial loans | Commercial real estate | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 3,307,076	$ 3,285,673
Commercial loans | Commercial real estate | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	25,217	24,428
Commercial loans | Commercial real estate | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	934	848
Commercial loans | Commercial real estate | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	145
Commercial loans | Commercial real estate | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	24,283	23,435
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,364,982	$ 2,315,318
% based on $, past due	0.30%	0.36%
Commercial loans | Commercial & industrial | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,357,841	$ 2,307,020
Commercial loans | Commercial & industrial | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	7,141	8,298
Commercial loans | Commercial & industrial | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,686	30
Commercial loans | Commercial & industrial | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	20	2,186
Commercial loans | Commercial & industrial | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	4,435	6,082
Commercial loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,695,506	$ 1,838,936
% based on $, past due	0%	0%
Commercial loans | Construction | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,695,506	$ 1,838,936
Commercial loans | Construction | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Construction | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Construction | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Construction | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable		0
Commercial loans | Land - acquisition & development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 148,711	$ 156,661
% based on $, past due	0%	0%
Commercial loans | Land - acquisition & development | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 148,711	$ 156,661
Commercial loans | Land - acquisition & development | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Land - acquisition & development | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Land - acquisition & development | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Commercial loans | Land - acquisition & development | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 7,199,993	$ 7,146,147
% based on $, past due	0.36%	0.43%
Consumer loans | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 7,174,426	$ 7,115,690
Consumer loans | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	25,567	30,457
Consumer loans | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	8,552	8,837
Consumer loans | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	4,112	9,351
Consumer loans | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	12,903	12,269
Consumer loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 263,638	$ 324,451
% based on $, past due	0.32%	1.07%
Consumer loans | Construction | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 262,791	$ 320,987
Consumer loans | Construction | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	847	3,464
Consumer loans | Construction | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	760	760
Consumer loans | Construction | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	2,617
Consumer loans | Construction | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	87	87
Consumer loans | Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 6,495,449	$ 6,388,990
% based on $, past due	0.34%	0.37%
Consumer loans | Single-family residential | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 6,473,306	$ 6,365,065
Consumer loans | Single-family residential | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	22,143	23,925
Consumer loans | Single-family residential | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	6,131	6,441
Consumer loans | Single-family residential | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	4,065	6,068
Consumer loans | Single-family residential | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	11,947	11,416
Consumer loans | Land - consumer lot loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 118,917	$ 124,842
% based on $, past due	0.33%	0.49%
Consumer loans | Land - consumer lot loans | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 118,524	$ 124,231
Consumer loans | Land - consumer lot loans | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	393	611
Consumer loans | Land - consumer lot loans | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	336	358
Consumer loans | Land - consumer lot loans | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	245
Consumer loans | Land - consumer lot loans | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	57	8
Consumer loans | HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 247,145	$ 237,754
% based on $, past due	0.67%	0.86%
Consumer loans | HELOC | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 245,477	$ 235,708
Consumer loans | HELOC | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,668	2,046
Consumer loans | HELOC | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,117	1,050
Consumer loans | HELOC | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	314
Consumer loans | HELOC | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	551	682
Consumer loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 74,844	$ 70,110
% based on $, past due	0.69%	0.59%
Consumer loans | Consumer | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 74,328	$ 69,699
Consumer loans | Consumer | Total Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	516	411
Consumer loans | Consumer | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	208	228
Consumer loans | Consumer | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	47	107
Consumer loans | Consumer | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 261	$ 76

Loans Receivable - Schedule o_2

Loans Receivable - Schedule of Loan Modifications (Details) - Term Extension $ in Thousands	3 Months Ended
	Dec. 31, 2023 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in period, amount	$ 8,303
% of Total Loan Class Balance	0.05%
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in period, amount	$ 8,303
% of Total Loan Class Balance	0.09%
Commercial loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in period, amount	$ 143
% of Total Loan Class Balance	0%
Wtd. Avg. Term Extension	20 months
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in period, amount	$ 7,814
% of Total Loan Class Balance	0.33%
Wtd. Avg. Term Extension	4 months
Commercial loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in period, amount	$ 346
% of Total Loan Class Balance	0.02%
Wtd. Avg. Term Extension	4 months

Loans Receivable - Loans Based

Loans Receivable - Loans Based on Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
Gross Charge-offs
Total Loans	$ 293	$ 228
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	112,774		$ 771,470
2023	844,582		2,845,113
2022	2,987,666		2,530,000
2021	2,470,087		1,239,813
2020	1,111,047		516,214
Prior to 2020	1,677,834		1,277,596
Revolving Loans	1,345,944		1,292,844
Revolving to Term Loans	14,015		34,560
Total Loans	10,563,949		10,507,610
Gross Charge-offs
YTD 2024	0
2023	0
2022	0
2021	0
2020	0
Prior to 2020	49
Revolving Loans	0
Revolving to Term Loans	31
Total Loans	80	82
Commercial loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	112,378		768,070
2023	840,865		2,732,691
2022	2,864,535		2,501,906
2021	2,446,355		1,210,070
2020	1,075,939		469,897
Prior to 2020	1,554,879		1,190,162
Revolving Loans	1,274,404		1,219,189
Revolving to Term Loans	14,014		27,681
Total Loans	10,183,369		10,119,666
Commercial loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		90,428
2022	90,668		788
2021	784		0
2020	0		6,999
Prior to 2020	0		0
Revolving Loans	2,850		3,707
Revolving to Term Loans	0		0
Total Loans	94,302		101,922
Commercial loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	396		3,400
2023	3,717		21,994
2022	32,463		27,306
2021	22,948		29,743
2020	35,108		39,318
Prior to 2020	122,955		87,434
Revolving Loans	68,690		69,948
Revolving to Term Loans	1		6,879
Total Loans	286,278		286,022
Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	10,416		135,859
2023	135,720		754,265
2022	874,986		853,307
2021	957,885		544,077
2020	464,585		143,548
Prior to 2020	529,354		406,015
Revolving Loans	35,552		49,523
Revolving to Term Loans	13,959		0
Total Loans	3,022,457		2,886,594
Gross Charge-offs
Total Loans	0	0
Commercial loans | Multi-family | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	10,416		135,859
2023	135,720		658,126
2022	778,628		850,998
2021	955,583		541,655
2020	462,169		135,965
Prior to 2020	521,665		400,412
Revolving Loans	35,552		49,523
Revolving to Term Loans	13,959		0
Total Loans	2,913,692		2,772,538
Commercial loans | Multi-family | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		90,428
2022	90,668		0
2021	0		0
2020	0		0
Prior to 2020	0		0
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	90,668		90,428
Commercial loans | Multi-family | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		5,711
2022	5,690		2,309
2021	2,302		2,422
2020	2,416		7,583
Prior to 2020	7,689		5,603
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	18,097		23,628
Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	61,720		221,556
2023	205,065		918,137
2022	991,674		739,667
2021	753,647		501,479
2020	474,763		294,920
Prior to 2020	843,107		631,993
Revolving Loans	2,317		2,349
Revolving to Term Loans	0		0
Total Loans	3,332,293		3,310,101
Gross Charge-offs
Total Loans	0	0
Commercial loans | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	61,720		221,057
2023	204,566		912,776
2022	979,199		735,069
2021	750,603		476,941
2020	444,855		262,945
Prior to 2020	777,833		596,459
Revolving Loans	2,317		2,349
Revolving to Term Loans	0		0
Total Loans	3,221,093		3,207,596
Commercial loans | Commercial real estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		788
2021	784		0
2020	0		4,059
Prior to 2020	0		0
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	784		4,847
Commercial loans | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		499
2023	499		5,361
2022	12,475		3,810
2021	2,260		24,538
2020	29,908		27,916
Prior to 2020	65,274		35,534
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	110,416		97,658
Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	13,685		155,411
2023	160,759		264,330
2022	295,156		325,250
2021	316,186		119,872
2020	115,583		31,005
Prior to 2020	237,805		221,339
Revolving Loans	1,225,752		1,163,551
Revolving to Term Loans	56		34,560
Total Loans	2,364,982		2,315,318
Gross Charge-offs
YTD 2024	0
2023	0
2022	0
2021	0
2020	0
Prior to 2020	31
Revolving Loans	0
Revolving to Term Loans	31
Total Loans	62	82
Commercial loans | Commercial & industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	13,685		155,411
2023	160,759		258,798
2022	284,699		316,713
2021	310,840		117,089
2020	112,799		24,246
Prior to 2020	187,813		175,042
Revolving Loans	1,154,212		1,089,896
Revolving to Term Loans	55		27,681
Total Loans	2,224,862		2,164,876
Commercial loans | Commercial & industrial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		2,940
Prior to 2020	0		0
Revolving Loans	2,850		3,707
Revolving to Term Loans	0		0
Total Loans	2,850		6,647
Commercial loans | Commercial & industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		5,532
2022	10,457		8,537
2021	5,346		2,783
2020	2,784		3,819
Prior to 2020	49,992		46,297
Revolving Loans	68,690		69,948
Revolving to Term Loans	1		6,879
Total Loans	137,270		143,795
Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	17,355		238,051
2023	324,942		838,696
2022	764,724		572,500
2021	409,587		68,105
2020	49,865		46,390
Prior to 2020	49,310		373
Revolving Loans	79,723		74,821
Revolving to Term Loans	0		0
Total Loans	1,695,506		1,838,936
Gross Charge-offs
Total Loans	0	0
Commercial loans | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	16,959		235,150
2023	321,724		833,577
2022	761,021		559,850
2021	396,547		68,105
2020	49,865		46,390
Prior to 2020	49,310		373
Revolving Loans	79,723		74,821
Revolving to Term Loans	0		0
Total Loans	1,675,149		1,818,266
Commercial loans | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	396		2,901
2023	3,218		5,119
2022	3,703		12,650
2021	13,040		0
2020	0		0
Prior to 2020	0		0
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	20,357		20,670
Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	9,598		20,593
2023	18,096		69,685
2022	61,126		39,276
2021	32,782		6,280
2020	6,251		351
Prior to 2020	18,258		17,876
Revolving Loans	2,600		2,600
Revolving to Term Loans	0		0
Total Loans	148,711		156,661
Gross Charge-offs
YTD 2024	0
2023	0
2022	0
2021	0
2020	0
Prior to 2020	18
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	18	0
Commercial loans | Land - acquisition & development | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	9,598		20,593
2023	18,096		69,414
2022	60,988		39,276
2021	32,782		6,280
2020	6,251		351
Prior to 2020	18,258		17,876
Revolving Loans	2,600		2,600
Revolving to Term Loans	0		0
Total Loans	148,573		156,390
Commercial loans | Land - acquisition & development | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		271
2022	138		0
2021	0		0
2020	0		0
Prior to 2020	0		0
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	138		271
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	55,919		625,700
2023	640,957		1,743,204
2022	1,757,745		1,776,345
2021	1,748,858		743,758
2020	736,578		300,626
Prior to 2020	1,983,376		1,694,901
Revolving Loans	276,154		259,975
Revolving to Term Loans	406		1,638
Total Loans	7,199,993		7,146,147
Gross Charge-offs
YTD 2024	0
2023	0
2022	0
2021	0
2020	0
Prior to 2020	116
Revolving Loans	97
Revolving to Term Loans	0
Total Loans	213	146
Consumer loans | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	55,919		624,878
2023	639,141		1,739,246
2022	1,755,229		1,772,797
2021	1,744,985		738,016
2020	735,150		300,376
Prior to 2020	1,968,801		1,680,457
Revolving Loans	274,795		258,283
Revolving to Term Loans	406		1,637
Total Loans	7,174,426		7,115,690
Consumer loans | 30 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		822
2023	820		875
2022	1,097		1,217
2021	1,806		392
2020	746		221
Prior to 2020	3,434		4,301
Revolving Loans	649		1,009
Revolving to Term Loans	0		0
Total Loans	8,552		8,837
Consumer loans | 60 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		1,526
2022	863		1,665
2021	1,335		3,942
2020	0		0
Prior to 2020	1,871		2,217
Revolving Loans	43		1
Revolving to Term Loans	0		0
Total Loans	4,112		9,351
Consumer loans | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	996		1,557
2022	556		666
2021	732		1,408
2020	682		29
Prior to 2020	9,270		7,926
Revolving Loans	667		682
Revolving to Term Loans	0		1
Total Loans	12,903		12,269
Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	1,331		92,081
2023	127,150		219,835
2022	132,464		8,838
2021	1,963		2,860
2020	372		358
Prior to 2020	358		479
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	263,638		324,451
Gross Charge-offs
Total Loans	0	0
Consumer loans | Construction | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	1,331		92,081
2023	127,150		218,988
2022	131,617		8,838
2021	1,963		243
2020	372		358
Prior to 2020	358		479
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	262,791		320,987
Consumer loans | Construction | 30 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		760
2022	760		0
2021	0		0
2020	0		0
Prior to 2020	0		0
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	760		760
Consumer loans | Construction | 60 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024			0
2023			0
2022			0
2021			2,617
2020			0
Prior to 2020			0
Revolving Loans			0
Revolving to Term Loans			0
Total Loans			2,617
Consumer loans | Construction | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		87
2022	87		0
2021	0		0
2020	0		0
Prior to 2020	0		0
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	87		87
Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	50,755		513,829
2023	494,818		1,481,590
2022	1,586,039		1,722,108
2021	1,707,441		721,375
2020	716,859		296,057
Prior to 2020	1,939,537		1,654,031
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	6,495,449		6,388,990
Gross Charge-offs
Total Loans	0	0
Consumer loans | Single-family residential | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	50,755		513,007
2023	493,002		1,478,479
2022	1,584,370		1,719,163
2021	1,703,961		718,250
2020	715,431		295,836
Prior to 2020	1,925,787		1,640,330
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	6,473,306		6,365,065
Consumer loans | Single-family residential | 30 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		822
2023	820		115
2022	337		859
2021	1,470		392
2020	746		221
Prior to 2020	2,758		4,032
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	6,131		6,441
Consumer loans | Single-family residential | 60 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		1,526
2022	863		1,420
2021	1,335		1,325
2020	0		0
Prior to 2020	1,867		1,797
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	4,065		6,068
Consumer loans | Single-family residential | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	996		1,470
2022	469		666
2021	675		1,408
2020	682		0
Prior to 2020	9,125		7,872
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	11,947		11,416
Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	3,804		19,128
2023	18,850		41,658
2022	39,120		35,651
2021	29,806		11,517
2020	11,342		4,166
Prior to 2020	15,995		12,722
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	118,917		124,842
Gross Charge-offs
Total Loans	0	0
Consumer loans | Land - consumer lot loans | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	3,804		19,128
2023	18,850		41,658
2022	39,120		35,048
2021	29,413		11,517
2020	11,342		4,166
Prior to 2020	15,995		12,714
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	118,524		124,231
Consumer loans | Land - consumer lot loans | 30 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		358
2021	336		0
2020	0		0
Prior to 2020	0		0
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	336		358
Consumer loans | Land - consumer lot loans | 60 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024			0
2023			0
2022			245
2021			0
2020			0
Prior to 2020			0
Revolving Loans			0
Revolving to Term Loans			0
Total Loans			245
Consumer loans | Land - consumer lot loans | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	57		0
2020	0		0
Prior to 2020	0		8
Revolving Loans	0		0
Revolving to Term Loans	0		0
Total Loans	57		8
Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		0
Prior to 2020	5,336		4,091
Revolving Loans	241,403		232,026
Revolving to Term Loans	406		1,637
Total Loans	247,145		237,754
Gross Charge-offs
Total Loans	0	0
Consumer loans | HELOC | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		0
Prior to 2020	4,797		3,733
Revolving Loans	240,274		230,338
Revolving to Term Loans	406		1,637
Total Loans	245,477		235,708
Consumer loans | HELOC | 30 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		0
Prior to 2020	531		44
Revolving Loans	586		1,006
Revolving to Term Loans	0		0
Total Loans	1,117		1,050
Consumer loans | HELOC | 60 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024			0
2023			0
2022			0
2021			0
2020			0
Prior to 2020			314
Revolving Loans			0
Revolving to Term Loans			0
Total Loans			314
Consumer loans | HELOC | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		0
Prior to 2020	8		0
Revolving Loans	543		682
Revolving to Term Loans	0		0
Total Loans	551		682
Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	29		662
2023	139		121
2022	122		9,748
2021	9,648		8,006
2020	8,005		45
Prior to 2020	22,150		23,578
Revolving Loans	34,751		27,949
Revolving to Term Loans	0		1
Total Loans	74,844		70,110
Gross Charge-offs
YTD 2024	0
2023	0
2022	0
2021	0
2020	0
Prior to 2020	116
Revolving Loans	97
Revolving to Term Loans	0
Total Loans	213	$ 146
Consumer loans | Consumer | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	29		662
2023	139		121
2022	122		9,748
2021	9,648		8,006
2020	8,005		16
Prior to 2020	21,864		23,201
Revolving Loans	34,521		27,945
Revolving to Term Loans	0		0
Total Loans	74,328		69,699
Consumer loans | Consumer | 30 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		0
Prior to 2020	145		225
Revolving Loans	63		3
Revolving to Term Loans	0		0
Total Loans	208		228
Consumer loans | Consumer | 60 Days Delinquent
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		0
Prior to 2020	4		106
Revolving Loans	43		1
Revolving to Term Loans	0		0
Total Loans	47		107
Consumer loans | Consumer | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2024	0		0
2023	0		0
2022	0		0
2021	0		0
2020	0		29
Prior to 2020	137		46
Revolving Loans	124		0
Revolving to Term Loans	0		1
Total Loans	$ 261		$ 76

Allowance for Loan Losses - All

Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	$ 177,207	$ 172,808
Charge-offs	(293)	(228)
Recoveries	406	717
Provision & Transfers	2,000	3,500
Ending Allowance	179,320	176,797
Provision recapture	(2,000)	(3,500)
Unfunded commitments
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision & Transfers	(2,000)	(1,000)
Provision recapture	2,000	1,000
Commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	137,194	133,476
Charge-offs	(80)	(82)
Recoveries	84	52
Provision & Transfers	1,957	4,836
Ending Allowance	139,155	138,282
Provision recapture	(1,957)	(4,836)
Commercial loans | Multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	13,155	12,013
Charge-offs	0	0
Recoveries	0	0
Provision & Transfers	636	311
Ending Allowance	13,791	12,324
Provision recapture	(636)	(311)
Commercial loans | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	28,842	25,814
Charge-offs	0	0
Recoveries	2	4
Provision & Transfers	163	1,562
Ending Allowance	29,007	27,380
Provision recapture	(163)	(1,562)
Commercial loans | Commercial & industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	58,773	57,210
Charge-offs	(62)	(82)
Recoveries	32	32
Provision & Transfers	2,093	6,713
Ending Allowance	60,836	63,873
Provision recapture	(2,093)	(6,713)
Commercial loans | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	29,408	26,161
Charge-offs	0	0
Recoveries	0	0
Provision & Transfers	(545)	(28)
Ending Allowance	28,863	26,133
Provision recapture	545	28
Commercial loans | Land - acquisition & development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	7,016	12,278
Charge-offs	(18)	0
Recoveries	50	16
Provision & Transfers	(390)	(3,722)
Ending Allowance	6,658	8,572
Provision recapture	390	3,722
Consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	40,013	39,332
Charge-offs	(213)	(146)
Recoveries	322	665
Provision & Transfers	43	(1,336)
Ending Allowance	40,165	38,515
Provision recapture	(43)	1,336
Consumer loans | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	2,781	3,410
Charge-offs	0	0
Recoveries	0	0
Provision & Transfers	(519)	90
Ending Allowance	2,262	3,500
Provision recapture	519	(90)
Consumer loans | Single-family residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	28,029	25,518
Charge-offs	0	0
Recoveries	120	430
Provision & Transfers	407	(473)
Ending Allowance	28,556	25,475
Provision recapture	(407)	473
Consumer loans | Land - consumer lot loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	3,512	5,047
Charge-offs	0	0
Recoveries	9	0
Provision & Transfers	(176)	(905)
Ending Allowance	3,345	4,142
Provision recapture	176	905
Consumer loans | HELOC
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	2,859	2,482
Charge-offs	0	0
Recoveries	1	1
Provision & Transfers	113	105
Ending Allowance	2,973	2,588
Provision recapture	(113)	(105)
Consumer loans | Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	2,832	2,875
Charge-offs	(213)	(146)
Recoveries	192	234
Provision & Transfers	218	(153)
Ending Allowance	3,029	2,810
Provision recapture	$ (218)	$ 153

Allowance for Loan Losses - Nar

Allowance for Loan Losses - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recoveries, net of charge-offs	$ 113	$ 489
Gross loans	$ 17,763,942		$ 17,653,757
Percent past due	0.33%		0.36%
Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 45,258		$ 50,422
Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 55,388		$ 57,924
Ratio of non-performing assets to total assets	0.24%		0.26%
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 10,563,949		$ 10,507,610
Percent past due	0.31%		0.31%
Commercial loans | Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 28,852		$ 34,644
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 2,364,982		$ 2,315,318
Percent past due	0.30%		0.36%
Commercial loans | Commercial & industrial | Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 4,437		$ 6,082

Allowance for Losses on Loans -

Allowance for Losses on Loans - Internally Assigned Grade (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 17,763,942	$ 17,653,757
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 17,364,033	$ 17,246,669
Pass | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	97.75%	97.69%
Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 94,302	$ 101,922
Special mention | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	0.53%	0.58%
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 305,607	$ 305,166
Substandard | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	1.72%	1.73%
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 0	$ 0
Doubtful | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	0%	0%
Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 0	$ 0
Loss | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	0%	0%
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 10,563,949	$ 10,507,610
Commercial loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	10,183,369	10,119,666
Commercial loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	94,302	101,922
Commercial loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	286,278	286,022
Commercial loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	3,022,457	2,886,594
Commercial loans | Multi-family | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,913,692	2,772,538
Commercial loans | Multi-family | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	90,668	90,428
Commercial loans | Multi-family | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	18,097	23,628
Commercial loans | Multi-family | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Multi-family | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	3,332,293	3,310,101
Commercial loans | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	3,221,093	3,207,596
Commercial loans | Commercial real estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	784	4,847
Commercial loans | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	110,416	97,658
Commercial loans | Commercial real estate | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Commercial real estate | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,364,982	2,315,318
Commercial loans | Commercial & industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,224,862	2,164,876
Commercial loans | Commercial & industrial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,850	6,647
Commercial loans | Commercial & industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	137,270	143,795
Commercial loans | Commercial & industrial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Commercial & industrial | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	1,695,506	1,838,936
Commercial loans | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	1,675,149	1,818,266
Commercial loans | Construction | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	20,357	20,670
Commercial loans | Construction | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Construction | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	148,711	156,661
Commercial loans | Land - acquisition & development | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	148,573	156,390
Commercial loans | Land - acquisition & development | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Land - acquisition & development | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	138	271
Commercial loans | Land - acquisition & development | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Commercial loans | Land - acquisition & development | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	7,199,993	7,146,147
Consumer loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	7,180,664	7,127,003
Consumer loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	19,329	19,144
Consumer loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	263,638	324,451
Consumer loans | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	263,550	324,363
Consumer loans | Construction | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	88	88
Consumer loans | Construction | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Construction | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	6,495,449	6,388,990
Consumer loans | Single-family residential | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	6,477,005	6,370,936
Consumer loans | Single-family residential | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Single-family residential | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	18,444	18,054
Consumer loans | Single-family residential | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Single-family residential | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	118,917	124,842
Consumer loans | Land - consumer lot loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	118,860	124,588
Consumer loans | Land - consumer lot loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Land - consumer lot loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	57	254
Consumer loans | Land - consumer lot loans | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Land - consumer lot loans | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	247,145	237,754
Consumer loans | HELOC | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	246,541	237,018
Consumer loans | HELOC | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | HELOC | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	604	736
Consumer loans | HELOC | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | HELOC | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	74,844	70,110
Consumer loans | Consumer | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	74,708	70,098
Consumer loans | Consumer | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Consumer | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	136	12
Consumer loans | Consumer | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	0	0
Consumer loans | Consumer | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 0	$ 0

Allowance for Losses on Loans_2

Allowance for Losses on Loans - Credit Risk Profile Based on Payment Activity (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 17,763,942	$ 17,653,757
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	10,563,949	10,507,610
Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	3,022,457	2,886,594
Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	3,332,293	3,310,101
Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	2,364,982	2,315,318
Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	1,695,506	1,838,936
Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	148,711	156,661
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	7,199,993	7,146,147
Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	263,638	324,451
Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	6,495,449	6,388,990
Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	118,917	124,842
Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	247,145	237,754
Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	74,844	70,110
Performing Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 17,718,684	$ 17,603,335
% of Total Loans	99.70%	99.70%
Performing Loans | Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 10,535,097	$ 10,472,966
% of Total Loans	99.70%	99.70%
Performing Loans | Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 3,022,325	$ 2,881,467
% of Total Loans	100%	99.80%
Performing Loans | Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 3,308,010	$ 3,286,666
% of Total Loans	99.30%	99.30%
Performing Loans | Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 2,360,545	$ 2,309,236
% of Total Loans	99.80%	99.70%
Performing Loans | Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 1,695,506	$ 1,838,936
% of Total Loans	100%	100%
Performing Loans | Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 148,711	$ 156,661
% of Total Loans	100%	100%
Performing Loans | Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 7,183,587	$ 7,130,369
% of Total Loans	99.80%	99.80%
Performing Loans | Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 263,550	$ 324,363
% of Total Loans	100%	100%
Performing Loans | Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 6,480,053	$ 6,374,072
% of Total Loans	99.80%	99.80%
Performing Loans | Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 118,860	$ 124,833
% of Total Loans	100%	100%
Performing Loans | Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 246,542	$ 237,018
% of Total Loans	99.80%	99.70%
Performing Loans | Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 74,582	$ 70,083
% of Total Loans	99.60%	100%
Non-Performing Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 45,258	$ 50,422
% of Total Loans	0.30%	0.30%
Non-Performing Loans | Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 28,852	$ 34,644
% of Total Loans	0.30%	0.30%
Non-Performing Loans | Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 132	$ 5,127
% of Total Loans	0%	0.20%
Non-Performing Loans | Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 24,283	$ 23,435
% of Total Loans	0.70%	0.70%
Non-Performing Loans | Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 4,437	$ 6,082
% of Total Loans	0.20%	0.30%
Non-Performing Loans | Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 0	$ 0
% of Total Loans	0%	0%
Non-Performing Loans | Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 0	$ 0
% of Total Loans	0%	0%
Non-Performing Loans | Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 16,406	$ 15,778
% of Total Loans	0.20%	0.20%
Non-Performing Loans | Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 88	$ 88
% of Total Loans	0%	0%
Non-Performing Loans | Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 15,396	$ 14,918
% of Total Loans	0.20%	0.20%
Non-Performing Loans | Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 57	$ 9
% of Total Loans	0%	0%
Non-Performing Loans | Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 603	$ 736
% of Total Loans	0.20%	0.30%
Non-Performing Loans | Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 262	$ 27
% of Total Loans	0.40%	0%

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	$ 2,018,445	$ 1,995,097
Total financial assets	2,389,387	2,350,285
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	2,018,445	1,995,097
Total financial assets	2,242,227	2,308,068
Total financial liabilities	56,392	79,668
Recurring | Client swap program hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	55,631	78,797
Derivative liabilities	56,392	79,668
Recurring | Commercial loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2,061	3,405
Recurring | Mortgage loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	22,244	46,396
Recurring | Borrowings cash flow hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	143,846	184,373
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Total financial assets	0	0
Total financial liabilities	0	0
Recurring | Level 1 | Client swap program hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring | Level 1 | Commercial loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Level 1 | Mortgage loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Level 1 | Borrowings cash flow hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	2,018,445	1,995,097
Total financial assets	2,242,227	2,308,068
Total financial liabilities	56,392	79,668
Recurring | Level 2 | Client swap program hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	55,631	78,797
Derivative liabilities	56,392	79,668
Recurring | Level 2 | Commercial loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2,061	3,405
Recurring | Level 2 | Mortgage loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	22,244	46,396
Recurring | Level 2 | Borrowings cash flow hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	143,846	184,373
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Total financial assets	0	0
Total financial liabilities	0	0
Recurring | Level 3 | Client swap program hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring | Level 3 | Commercial loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Level 3 | Mortgage loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Level 3 | Borrowings cash flow hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
U.S. government and agency securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	232,359	217,053
U.S. government and agency securities | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
U.S. government and agency securities | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	232,359	217,053
U.S. government and agency securities | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Asset-backed securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	561,304	588,016
Asset-backed securities | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Asset-backed securities | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	561,304	588,016
Asset-backed securities | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0
Municipal bonds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	35,206	34,662
Municipal bonds | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Municipal bonds | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	35,206	34,662
Municipal bonds | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Corporate debt securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	248,813	242,522
Corporate debt securities | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Corporate debt securities | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	248,813	242,522
Corporate debt securities | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Agency pass-through certificates | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	940,763	912,844
Agency pass-through certificates | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Agency pass-through certificates | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	940,763	912,844
Agency pass-through certificates | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	$ 0	$ 0

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value Measured on Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	$ 781	$ 0
Loans receivable/Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	781	0
Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	0	0
Changes measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total gains (losses)	(158)	(123)
Changes measurement | Loans receivable/Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total gains (losses)	(158)	(123)
Changes measurement | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total gains (losses)	0	0
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	0	0
Level 1 | Loans receivable/Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	0	0
Level 1 | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	0	0
Level 2 | Loans receivable/Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	0	0
Level 2 | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	781	0
Level 3 | Loans receivable/Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	781	0
Level 3 | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Sep. 30, 2023
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Available-for-sale securities purchased	$ 49,380,000	$ 115,909,000
Proceeds from sales of available-for-sale securities	2,624,000	0
Held-to-maturity securities purchased	0	0
Proceeds from sale of held-to-maturity securities	$ 0	$ 0
Term of contractual due dates, mortgage-backed securities	25 years
Accrued interest for available-for-sale securities	$ 8,270,000		$ 8,641,000
Accrued interest for held-to-maturity securities	992,000		$ 1,013,000
Consumer loans | Single-family residential
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Foreclosed residential real estate properties held as REO	121,000
Real estate acquired through foreclosure	$ 3,338,000

Fair Value Measurements - Fai_3

Fair Value Measurements - Fair Value by Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	$ 2,018,445	$ 1,995,097
Held-to-maturity securities, at amortized cost	415,079	423,586
FHLB stock	137,940	126,820
Agency pass-through certificates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, at amortized cost	415,079	423,586
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	2,018,445	1,995,097
Held-to-maturity securities, at amortized cost	415,079	423,586
Carrying Amount | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,144,774	980,649
Carrying Amount | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
FHLB stock	137,940	126,820
Time deposits	5,380,723	5,305,016
Borrowings	3,875,000	3,650,000
Carrying Amount | Level 2 | Client swap program hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	55,631	78,797
Other liabilities	56,392	79,668
Carrying Amount | Level 2 | Commercial loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	2,061	3,405
Carrying Amount | Level 2 | Mortgage loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	22,244	46,396
Carrying Amount | Level 2 | Borrowings cash flow hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	143,846	184,373
Carrying Amount | Level 2 | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	232,359	217,053
Carrying Amount | Level 2 | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	561,304	588,016
Carrying Amount | Level 2 | Municipal bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	35,206	34,662
Carrying Amount | Level 2 | Corporate debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	248,813	242,522
Carrying Amount | Level 2 | Agency pass-through certificates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	940,763	912,844
Held-to-maturity securities, at amortized cost	415,079	423,586
Carrying Amount | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable	17,584,622	17,476,550
Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	2,018,445	1,995,097
Held-to-maturity securities, at amortized cost	370,942	355,188
Estimated Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,144,774	980,649
Estimated Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
FHLB stock	137,940	126,820
Time deposits	5,363,731	5,232,689
Borrowings	3,867,812	3,653,229
Estimated Fair Value | Level 2 | Client swap program hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	55,631	78,797
Other liabilities	56,392	79,668
Estimated Fair Value | Level 2 | Commercial loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	2,061	3,405
Estimated Fair Value | Level 2 | Mortgage loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	22,244	46,396
Estimated Fair Value | Level 2 | Borrowings cash flow hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	143,846	184,373
Estimated Fair Value | Level 2 | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	232,359	217,053
Estimated Fair Value | Level 2 | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	561,304	588,016
Estimated Fair Value | Level 2 | Municipal bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	35,206	34,662
Estimated Fair Value | Level 2 | Corporate debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	248,813	242,522
Estimated Fair Value | Level 2 | Agency pass-through certificates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	940,763	912,844
Held-to-maturity securities, at amortized cost	370,942	355,188
Estimated Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable	$ 16,876,965	$ 16,559,758

Fair Value Measurements - Inves

Fair Value Measurements - Investments by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Amortized Cost, Available-for-sale securities
Amortized cost	$ 2,101,314	$ 2,118,616
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains	2,075	2,910
Gross unrealized loss	(84,944)	(126,429)
Fair Value, Available-for-sale securities
Fair value	$ 2,018,445	$ 1,995,097
Yield, Available-for-sale securities
Yield	4.69%	4.64%
Amortized Cost, Held-to-maturity securities
Held-to-maturity securities	$ 415,079	$ 423,586
Gross Unrealized Gains / Losses, Held-to-maturity securities
Held-to-maturity securities, gross unrealized gains	27	0
Held-to-maturity securities, gross unrealized losses	(44,164)	(68,398)
Fair Value, Held-to-maturity securities
Held-to-maturity securities, fair value	$ 370,942	$ 355,188
Yield, Held-to-maturity securities
Held-to-maturity securities, yield	2.88%	2.88%
Investments	$ 2,516,393	$ 2,542,202
Gross unrealized gains on investments	2,102	2,910
Gross unrealized losses on investments	(129,108)	(194,827)
Total financial assets	$ 2,389,387	$ 2,350,285
Yield on investments	4.39%	4.35%
U.S. government and agency securities
Amortized Cost, Available-for-sale securities
Amortized cost, within 1 year	$ 1,750	$ 3,501
Amortized cost, 1 to 5 years	16,747	18,894
Amortized cost, 5 to 10 years	110,295	87,922
Amortized cost, over 10 years	103,594	106,340
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, within 1 year	0	0
Gross unrealized gains, 1 to 5 years	8	0
Gross unrealized gains, 5 to 10 years	189	177
Gross unrealized gains, over 10 years	267	831
Gross unrealized losses, Within 1 year	(5)	(36)
Gross unrealized losses, 1 to 5 years	(305)	(563)
Gross unrealized losses, 5 to 10 years	(173)	0
Gross unrealized losses, over 10 years	(8)	(13)
Fair Value, Available-for-sale securities
Fair value, within 1 year	1,745	3,465
Fair value, 1 to 5 years	16,450	18,331
Fair value, 5 to 10 years	110,311	88,099
Fair value, over 10 years	$ 103,853	$ 107,158
Yield, Available-for-sale securities
Yield, within 1 year	6.07%	6.06%
Yield, 1 to 5 years	4.54%	4.70%
Yield, 5 to 10 years	6.01%	5.76%
Yield, over 10 years	6.09%	5.84%
Asset-backed securities
Amortized Cost, Available-for-sale securities
Amortized cost, 1 to 5 years	$ 17,693	$ 18,579
Amortized cost, 5 to 10 years	31,469	36,875
Amortized cost, over 10 years	519,103	539,911
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, 1 to 5 years	0	0
Gross unrealized gains, 5 to 10 years	14	2
Gross unrealized gains, over 10 years	316	578
Gross unrealized losses, 1 to 5 years	(766)	(715)
Gross unrealized losses, 5 to 10 years	(205)	(99)
Gross unrealized losses, over 10 years	(6,320)	(7,115)
Fair Value, Available-for-sale securities
Fair value, 1 to 5 years	16,927	17,864
Fair value, 5 to 10 years	31,278	36,778
Fair value, over 10 years	$ 513,099	$ 533,374
Yield, Available-for-sale securities
Yield, 1 to 5 years	6.08%	6.06%
Yield, 5 to 10 years	6.23%	6.11%
Yield, over 10 years	6.37%	6.35%
Corporate debt securities
Amortized Cost, Available-for-sale securities
Amortized cost, 1 to 5 years	$ 152,022	$ 151,893
Amortized cost, 5 to 10 years	112,923	113,221
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, 1 to 5 years	479	895
Gross unrealized gains, 5 to 10 years	0	0
Gross unrealized losses, 1 to 5 years	(1,196)	(1,787)
Gross unrealized losses, 5 to 10 years	(15,415)	(21,700)
Fair Value, Available-for-sale securities
Fair value, 1 to 5 years	151,305	151,001
Fair value, 5 to 10 years	$ 97,508	$ 91,521
Yield, Available-for-sale securities
Yield, 1 to 5 years	5.15%	5.14%
Yield, 5 to 10 years	3.87%	3.87%
Municipal bonds due
Amortized Cost, Available-for-sale securities
Amortized cost, 5 to 10 years	$ 5,712	$ 5,720
Amortized cost, over 10 years	29,822	29,832
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, 5 to 10 years	0	0
Gross unrealized gains, over 10 years	95	361
Gross unrealized losses, 5 to 10 years	(298)	(701)
Gross unrealized losses, over 10 years	(125)	(550)
Fair Value, Available-for-sale securities
Fair value, 5 to 10 years	5,414	5,019
Fair value, over 10 years	$ 29,792	$ 29,643
Yield, Available-for-sale securities
Yield, 5 to 10 years	3%	3%
Yield, over 10 years	5.85%	5.85%
Agency pass-through certificates
Amortized Cost, Available-for-sale securities
Amortized cost, without single maturity date	$ 1,000,184	$ 1,005,928
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, without single maturity date	707	66
Gross unrealized losses, without single maturity date	(60,128)	(93,150)
Fair Value, Available-for-sale securities
Fair value, without single maturity date	$ 940,763	$ 912,844
Yield, Available-for-sale securities
Yield, without single maturity date	3.44%	3.39%
Amortized Cost, Held-to-maturity securities
Held-to-maturity securities	$ 415,079	$ 423,586
Gross Unrealized Gains / Losses, Held-to-maturity securities
Held-to-maturity securities, gross unrealized gains	27	0
Held-to-maturity securities, gross unrealized losses	(44,164)	(68,398)
Fair Value, Held-to-maturity securities
Held-to-maturity securities, fair value	$ 370,942	$ 355,188
Yield, Held-to-maturity securities
Held-to-maturity securities, yield	2.88%	2.88%

Fair Value Measurements - Secur

Fair Value Measurements - Securities in Unrealized Loss Positions (Details) $ in Thousands	Dec. 31, 2023 USD ($) security	Sep. 30, 2023 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Number of debt securities with unrealized loss | security	220	231
Available-for-sale securities
Less than 12 months, unrealized gross losses	$ (253)	$ (4,185)
12 months or more, unrealized gross losses	(84,691)	(122,244)
Total unrealized gross losses	(84,944)	(126,429)
Less than 12 months, fair value	152,930	243,952
12 months or more, fair value	1,481,661	1,393,013
Total, fair value	1,634,591	1,636,965
Held-to-maturity securities
Less than 12 months, unrealized gross losses	0	(15)
Less than 12 months, fair value	0	1,424
12 months or more, unrealized gross losses	(44,164)	(68,383)
12 months or more, fair value	369,265	353,764
Total unrealized gross losses	(44,164)	(68,398)
Total, fair value	369,265	355,188
Less than 12 months, unrealized gross losses	(253)	(4,200)
Less than 12 months, fair value	152,930	245,376
12 months or more, unrealized gross losses	(128,855)	(190,627)
12 months or more, fair value	1,850,926	1,746,777
Total unrealized gross losses	(129,108)	(194,827)
Total fair value	2,003,856	1,992,153
Corporate debt securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	0	0
12 months or more, unrealized gross losses	(16,611)	(23,487)
Total unrealized gross losses	(16,611)	(23,487)
Less than 12 months, fair value	0	0
12 months or more, fair value	174,074	167,452
Total, fair value	174,074	167,452
Municipal bonds due
Available-for-sale securities
Less than 12 months, unrealized gross losses	0	0
12 months or more, unrealized gross losses	(423)	(1,250)
Total unrealized gross losses	(423)	(1,250)
Less than 12 months, fair value	0	0
12 months or more, fair value	15,111	14,302
Total, fair value	15,111	14,302
U.S. government and agency securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	(181)	(13)
12 months or more, unrealized gross losses	(310)	(599)
Total unrealized gross losses	(491)	(612)
Less than 12 months, fair value	134,687	14,917
12 months or more, fair value	13,720	21,795
Total, fair value	148,407	36,712
Asset-backed securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	0	(2,142)
12 months or more, unrealized gross losses	(7,291)	(5,788)
Total unrealized gross losses	(7,291)	(7,930)
Less than 12 months, fair value	0	86,800
12 months or more, fair value	522,583	445,454
Total, fair value	522,583	532,254
Mortgage-backed securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	(72)	(2,030)
12 months or more, unrealized gross losses	(60,056)	(91,120)
Total unrealized gross losses	(60,128)	(93,150)
Less than 12 months, fair value	18,243	142,235
12 months or more, fair value	756,173	744,010
Total, fair value	$ 774,416	$ 886,245

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities - Summary of Fair Value, Notional Amount and Balance Sheet Classification (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Other assets
Derivatives, Fair Value [Line Items]
Notional amount	$ 2,903,527	$ 2,516,405
Derivative assets, fair value	223,782	312,971
Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	896,485	806,744
Derivative liabilities, fair value	56,392	79,668
Client swap program hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	896,485	806,744
Derivative assets, fair value	55,631	78,797
Client swap program hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	896,485	806,744
Derivative liabilities, fair value	56,392	79,668
Commercial loan fair value hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	37,042	39,661
Derivative assets, fair value	2,061	3,405
Commercial loan fair value hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	0	0
Derivative liabilities, fair value	0	0
Mortgage loan fair value hedges
Derivatives, Fair Value [Line Items]
Notional amount	970,000	670,000
Mortgage loan fair value hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	970,000
Derivative assets, fair value	22,244	46,396
Mortgage loan fair value hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	0	0
Derivative liabilities, fair value	0	0
Borrowings cash flow hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	1,000,000	1,000,000
Derivative assets, fair value	143,846	184,373
Borrowings cash flow hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	0	0
Derivative liabilities, fair value	$ 0	$ 0

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities - Impact of Fair Value Hedge Accounting on the Carrying Value of the Hedged Items (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Derivatives, Fair Value [Line Items]
Carrying value of hedged items	$ 6,246,208	$ 1,816,870
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	(23,255)	(48,865)
Mortgage loan fair value hedges
Derivatives, Fair Value [Line Items]
Carrying value of hedged items	6,211,195	1,780,503
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	(21,277)	(45,622)
Notional amount	970,000	670,000
Commercial loan fair value hedges
Derivatives, Fair Value [Line Items]
Carrying value of hedged items	35,013	36,367
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	$ (1,978)	$ (3,243)

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities - Narrative (Details) - USD ($)	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Interest Rate Swap | Minimum
Derivative [Line Items]
Derivative, maturities	1 year
Interest Rate Swap | Maximum
Derivative [Line Items]
Derivative, maturities	6 years
Interest Rate Swap | Weighted average
Derivative [Line Items]
Derivative, maturities	5 years 3 months 18 days
Interest rate contracts
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 109,000	$ 0

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities - Impact of Derivative Instruments on AOCI (Details) - Cash flow hedging - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Total pre-tax gain/(loss) recognized in AOCI	$ (40,527)	$ (6,806)
Pay fixed/receive floating swaps on borrowings cash flow hedges
Derivative [Line Items]
Pay fixed/receive floating swaps on borrowings cash flow hedges	$ (40,527)	$ (6,806)

Derivatives and Hedging Activ_7

Derivatives and Hedging Activities - Gains/(Losses) on Derivative Instruments in Fair Value and Cash Flow Accounting Hedging Relationships (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Interest income/(expense), including the effects of fair value and cash flow hedges	$ 245,792	$ 203,946
Interest income/(expense), including the effects of fair value and cash flow hedges	(37,938)	(18,974)
Interest rate contracts | Interest income on loans receivable | Fair value hedging
Gain/(loss) on fair value hedging relationships:
Amounts related to interest settlements on derivatives	5,493	3,167
Recognized on derivatives	(25,496)	(2,849)
Recognized on hedged items	25,610	3,132
Net income/(expense) recognized on fair value hedges	5,607	3,450
Interest rate contracts | Interest expense on FHLB advances | Cash flow hedging
Gain/(loss) on cash flow hedging relationships:
Amounts related to interest settlements on derivatives	11,847	7,274
Amount of derivative gain/(loss) reclassified from AOCI into interest income/expense	0	0
Gain (loss) recognized on cash flow hedges	$ 11,847	$ 7,274

Derivatives and Hedging Activ_8

Derivatives and Hedging Activities - Impact of Client Swap Program that are Not Designated in Accounting Hedges (Details) - USD ($)	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Client swap program hedges
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 109,000	$ 0
Other noninterest income | Pay fixed/receive floating swap
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	(28,709,000)	(3,878,000)
Other noninterest income | Receive fixed/pay floating swap
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 28,818,000	$ 3,878,000

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Details)	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue streams percentage, contract with customer	3.60%	3.90%

Commitment and Contingencies (D

Commitment and Contingencies (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans in process	$ 1,516,522	$ 1,895,940
Off-balance-sheet credit reserve	22,500	24,500
Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans in process	$ 3,180,001	$ 3,625,333