Washington Federal (WAFD) 10-Q 3 May 22 2022 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Mar. 31, 2022	Apr. 28, 2022
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-34654
Entity Registrant Name	WASHINGTON FEDERAL 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		65,307,718
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
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 - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
ASSETS
Cash and cash equivalents	$ 1,947,504	$ 2,090,809
Available-for-sale securities, at fair value	1,909,605	2,138,259
Held-to-maturity securities, at amortized cost	301,221	366,025
Loans receivable, net of allowance for loan losses of $171,384 and $171,300	15,094,926	13,833,570
Interest receivable	51,440	50,636
Premises and equipment, net	247,166	255,152
Real estate owned	9,509	8,204
FHLB and FRB stock	78,873	102,863
Bank owned life insurance	236,024	233,263
Intangible assets, including goodwill of $303,457 and $303,457	309,501	310,019
Federal and state income tax assets, net	3,821	3,877
Other assets	370,689	257,897
Total Assets	20,560,279	19,650,574
Customer accounts
Transaction deposit accounts	13,139,606	12,108,025
Time deposit accounts	3,251,042	3,434,087
Total customer accounts	16,390,648	15,542,112
FHLB advances	1,720,000	1,720,000
Advance payments by borrowers for taxes and insurance	39,426	47,016
Accrued expenses and other liabilities	218,504	215,382
Total Liabilities	18,368,578	17,524,510
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; 136,243,712 and 135,993,254 shares issued; 65,306,928 and 65,145,268 shares outstanding	136,244	135,993
Additional paid-in capital	1,683,578	1,678,622
Accumulated other comprehensive income (loss), net of taxes	71,478	69,785
Treasury stock, at cost; 70,936,784 and 70,847,986 shares	(1,590,082)	(1,586,947)
Retained earnings	1,590,483	1,528,611
Total stockholders' equity	2,191,701	2,126,064
Total Liabilities and Shareholders' equity	$ 20,560,279	$ 19,650,574

CONSOLIDATED STATEMENTS OF FI_2

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Statement of Financial Position [Abstract]
Allowance for credit losses on loans	$ 171,384	$ 171,300
Goodwill	$ 303,457	$ 303,457
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)	136,243,712	135,993,254
Common stock, shares outstanding (in shares)	65,306,928	65,145,268
Treasury stock, shares (in shares)	70,936,784	70,847,986

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
INTEREST INCOME
Loans receivable	$ 139,260	$ 132,757	$ 277,769	$ 266,428
Mortgage-backed securities	4,659	6,696	9,451	13,926
Investment securities and cash equivalents	6,919	7,301	14,058	14,222
Interest income	150,838	146,754	301,278	294,576
INTEREST EXPENSE
Customer accounts	8,225	10,729	16,686	24,839
FHLB advances	7,525	11,991	15,368	25,189
Interest expense	15,750	22,720	32,054	50,028
Net interest income	135,088	124,034	269,224	244,548
Provision (release) for credit losses	(500)	0	0	3,000
Net interest income after provision (release)	135,588	124,034	269,224	241,548
OTHER INCOME
Gain (loss) on sale of investment securities	0	0	81	0
Gain (loss) on termination of hedging derivatives	0	14,110	0	14,110
Prepayment penalty from repayment of borrowings	0	(13,788)	0	(13,788)
Loan fee income	$ 2,475	$ 872	$ 4,396	$ 3,264
Revenue, Product and Service [Extensible Enumeration]	Deposit Account [Member]	Deposit Account [Member]	Deposit Account [Member]	Deposit Account [Member]
Deposit fee income	$ 6,282	$ 5,960	$ 12,725	$ 11,986
Other income	6,902	7,323	17,138	12,775
Other income, total	15,659	14,477	34,340	28,347
OTHER EXPENSE
Compensation and benefits	47,115	43,632	94,540	86,355
Occupancy	11,788	10,473	21,878	20,065
FDIC insurance premiums	2,100	3,755	5,200	7,018
Product delivery	5,044	4,401	9,765	9,338
Information technology	11,722	10,696	23,143	22,527
Other expense	10,648	8,789	23,504	17,853
Other expense, total	88,417	81,746	178,030	163,156
Gain (loss) on real estate owned, net	129	34	691	(415)
Income before income taxes	62,959	56,799	126,225	106,324
Income tax expense	13,600	11,928	26,585	22,502
Net income	49,359	44,871	99,640	83,822
Dividends on preferred stock	3,656	2,722	7,312	2,722
Net income available to common shareholders	$ 45,703	$ 42,149	$ 92,328	$ 81,100
PER SHARE DATA
Basic earnings per common share (in dollars per share)	$ 0.70	$ 0.56	$ 1.41	$ 1.07
Diluted earnings per common share (in dollars per share)	0.70	0.56	1.41	1.07
Dividends paid on common stock per share (in dollars per share)	$ 0.24	$ 0.23	$ 0.47	$ 0.45
Basic weighted average number of shares outstanding (in shares)	65,301,171	75,354,765	65,253,991	75,576,288
Diluted weighted average number of shares outstanding (in shares)	65,445,206	75,393,464	65,397,601	75,582,426

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 49,359	$ 44,871	$ 99,640	$ 83,822
Other comprehensive income (loss) net of tax:
Net unrealized gain (loss) during the period on available-for-sale investment securities, net of tax	(33,767)	(3,729)	(46,701)	5,262
Reclassification adjustment of net (gain) loss from sale of available-for-sale securities included in net income, net of tax	0	0	62	0
Net unrealized gain (loss) from investment securities, net of reclassification adjustment	(33,767)	(3,729)	(46,639)	5,262
Net unrealized gain (loss) during the period on borrowings cash flow hedges, net of tax	43,369	54,335	48,332	69,826
Reclassification adjustment of net (gain) loss included in net income during the period from hedging derivatives, net of tax	0	(10,865)	0	(10,865)
Net unrealized gain (loss) in cash flow hedging instruments, net of reclassification adjustment	43,369	43,470	48,332	58,961
Other comprehensive income (loss)	9,602	39,741	1,693	64,223
Comprehensive income	$ 58,961	$ 84,612	$ 101,333	$ 148,045

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Related tax benefit (expense) for net unrealized gain (loss) on available-for-sale debt securities	$ 10,086	$ 1,114	$ 13,950	$ (1,572)
Reclassification adjustment of net (gain) loss from sale of available-for-sale securities included in net income, tax	0	0	(19)	0
Related tax benefit (expense) for net unrealized gain (loss) on borrowing cash flow hedges	(12,954)	(16,230)	(14,437)	(20,857)
Reclassification adjustment of net (gain) loss included in net income during the period from hedging derivatives, tax	$ 0	$ 3,245	$ 0	$ 3,245

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - 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, 2020	$ 2,014,133	$ 0	$ 135,727	$ 1,678,843	$ 1,420,906	$ 16,953	$ (1,238,296)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	83,822				83,822
Other comprehensive income (loss)	64,223					64,223
Issuance of preferred stock, net	293,325	300,000		(6,675)
Dividends on common stock	(33,913)				(33,913)
Dividends on preferred stock	(2,722)				(2,722)
Proceeds from stock-based awards	330		20	310
Stock-based compensation expense	3,527		233	3,294
Treasury stock acquired	(89,772)						(89,772)
Balance, end of period at Mar. 31, 2021	2,332,953	300,000	135,980	1,675,772	1,468,093	81,176	(1,328,068)
Balance, beginning of period at Dec. 31, 2020	2,061,767	0	135,938	1,680,111	1,443,280	41,435	(1,238,997)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	44,871				44,871
Other comprehensive income (loss)	39,741					39,741
Issuance of preferred stock, net	293,325	300,000		(6,675)
Dividends on common stock	(17,336)				(17,336)
Dividends on preferred stock	(2,722)
Proceeds from stock-based awards	300		18	282
Stock-based compensation expense	2,078		24	2,054
Treasury stock acquired	(89,071)						(89,071)
Balance, end of period at Mar. 31, 2021	2,332,953	300,000	135,980	1,675,772	1,468,093	81,176	(1,328,068)
Balance, beginning of period at Sep. 30, 2021	2,126,064	300,000	135,993	1,678,622	1,528,611	69,785	(1,586,947)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	99,640				99,640
Other comprehensive income (loss)	1,693					1,693
Dividends on common stock	(30,456)				(30,456)
Dividends on preferred stock	(7,312)				(7,312)
Proceeds from stock-based awards	1,361		49	1,312
Stock-based compensation expense	3,846		202	3,644
Treasury stock acquired	(3,135)						(3,135)
Balance, end of period at Mar. 31, 2022	2,191,701	300,000	136,244	1,683,578	1,590,483	71,478	(1,590,082)
Balance, beginning of period at Dec. 31, 2021	2,149,126	300,000	136,196	1,680,637	1,560,337	61,876	(1,589,920)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	49,359				49,359
Other comprehensive income (loss)	9,602					9,602
Dividends on common stock	(15,557)				(15,557)
Dividends on preferred stock	(3,656)
Proceeds from stock-based awards	533		19	514
Stock-based compensation expense	2,456		29	2,427
Treasury stock acquired	(162)						(162)
Balance, end of period at Mar. 31, 2022	$ 2,191,701	$ 300,000	$ 136,244	$ 1,683,578	$ 1,590,483	$ 71,478	$ (1,590,082)

CONSOLIDATED STATEMENTS OF SH_2

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Statement of Stockholders' Equity [Abstract]
Dividends paid on common stock per share (in dollars per share)	$ 0.24	$ 0.23	$ 0.47	$ 0.45
Dividends paid on preferred stock, per share (in dollars per share)	$ 12.1875	$ 9.0729	$ 24.3750	$ 9.0729

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 99,640,000	$ 83,822,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, accretion and other, net	31,110,000	36,608,000
Stock-based compensation expense	3,846,000	3,527,000
Provision (release) for credit losses	0	3,000,000
Loss (gain) on sale of investment securities	(81,000)	0
Net realized (gain) loss on sales of premises, equipment, and real estate owned	74,000	37,000
Prepayment penalty from repayment of borrowings	0	13,788,000
Gain on early termination of long term borrowing hedge	0	(14,110,000)
Decrease (increase) in accrued interest receivable	(804,000)	(274,000)
Decrease (increase) in federal and state income tax receivable	(450,000)	5,708,000
Decrease (increase) in cash surrender value of bank owned life insurance	(2,761,000)	(2,771,000)
Decrease (increase) in other assets	(38,217,000)	156,599,000
Increase (decrease) in federal and state income tax liabilities	0	(5,760,000)
Increase (decrease) in accrued expenses and other liabilities	(9,107,000)	(75,419,000)
Net cash provided by (used in) operating activities	83,250,000	204,755,000
CASH FLOWS FROM INVESTING ACTIVITIES
Origination of loans and principal repayments, net	(754,450,000)	(192,028,000)
Loans purchased	(525,825,000)	(73,208,000)
FHLB & FRB stock purchased	(108,000,000)	(188,001,000)
FHLB & FRB stock redeemed	131,990,000	210,000,000
Available-for-sale securities purchased	(124,651,000)	(522,454,000)
Principal payments and maturities of available-for-sale securities	287,775,000	338,869,000
Proceeds from sales of available-for-sale securities	4,510,000	0
Principal payments and maturities of held-to-maturity securities	63,214,000	206,868,000
Proceeds from sales of real estate owned	3,175,000	637,000
Proceeds from sales of premises and equipment	41,000	3,376,000
Premises and equipment purchased and REO improvements	(5,738,000)	(20,260,000)
Net cash provided by (used in) investing activities	(1,027,959,000)	(236,201,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in customer accounts	848,536,000	1,039,797,000
Proceeds from borrowings	2,700,000,000	4,700,007,000
Repayments of borrowings	(2,700,000,000)	(5,263,795,000)
Proceeds from the early termination of long term borrowing hedge	0	14,110,000
Proceeds from stock-based awards	1,361,000	330,000
Proceeds from issuance of preferred stock, net	0	293,325,000
Dividends paid on common stock	(30,456,000)	(33,913,000)
Dividends paid on preferred stock	(7,312,000)	0
Treasury stock purchased	(3,135,000)	(89,772,000)
Increase (decrease) in advances payments by borrowers for taxes and insurance	(7,590,000)	(13,173,000)
Net cash provided by (used in) financing activities	801,404,000	646,916,000
Increase (decrease) in cash and cash equivalents	(143,305,000)	615,470,000
Cash, cash equivalents and restricted cash at beginning of period	2,090,809,000	1,702,977,000
Cash, cash equivalents and restricted cash at end of period	1,947,504,000	2,318,447,000
Non-cash investing activities
Real estate acquired through foreclosure	0	105,000
Other personal property acquired through foreclosure	422,000	0
Non-cash financing activities
Preferred stock dividend payable	3,656,000	2,722,000
Cash paid (received) during the period for
Interest	25,979,000	41,707,000
Income taxes	$ 19,001,000	$ 14,745,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Mar. 31, 2022
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 (the “Company”), was formed as the Bank’s holding company in November, 1994. As used throughout this document, the terms “Washington Federal” or the “Company” refer to the Company and its consolidated subsidiaries, and the term “Bank” refers to the operating subsidiary, Washington Federal Bank, a Washington state chartered commercial bank. The Company is headquartered in Seattle, Washington. The Bank conducts its activities through a network of 214 bank branches located in Washington, Oregon, Idaho, Utah, Arizona, Nevada, New Mexico and Texas. On February 4, 2022, the Bank completed the conversion of its charter from a national bank charter, supervised by the Office of the Comptroller of the Currency, to a Washington state chartered commercial bank effective February 4, 2022. The Bank cancelled its holdings of stock in the Federal Reserve Bank of San Francisco as part of the conversion and its legal name changed from “Washington Federal Bank, National Association” to “Washington Federal Bank.” As a result of the conversion, the Washington State Department of Financial Institutions is the Bank's primary state regulator and the Federal Deposit Insurance Corporation (the "FDIC") is the Bank's primary federal regulator. The Federal Reserve will continue to regulate the Bank's holding company Washington Federal, Inc. 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 in the Company's 2021 Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on November 19, 2021 ("2021 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 2021 Annual Financial Statements. There have not been any significant changes in the Company's significant accounting policies compared to those contained in its 2021 Annual Financial Statements for the year ended September 30, 2021. 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 March 31, 2022. As of March 31, 2022 and September 30, 2021, the Company held counterparty cash collateral of $153,000,000 and pledged cash collateral to counterparties of $1,500,000, respectively, related to derivative contracts. Equity Securities - The Company records equity securities within Other assets in its Consolidated Statements of Financial Condition. Investments in equity securities with readily determinable fair values (marketable) are measured at fair value, with changes in the fair value recognized as a component of Other income in the Consolidated Statements of Operations. Investments in equity investments that do not have readily determinable fair values (non-marketable) are accounted for at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer, also referred to as the measurement alternative. Any adjustments to the carrying value of these investments are recorded in Other income in the Consolidated Statements of Operations. 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 CECL methodology requires an estimate of the credit losses expected over the life of an exposure (or pool of exposures) and replaces the incurred loss methodology’s threshold that delayed the recognition of a credit loss until it was probable a loss event was incurred. 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 most of our 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. When management deems it to be appropriate, the Company establishes a specific reserve for individually evaluated loans that do not share similar risk characteristics with the loans included in each respective loan pool. These individually evaluated loans are removed from their respective pools and typically represent collateral dependent loans but may also include other non-performing loans or troubled debt restructurings (“TDRs”). In addition, the Company individually evaluates “reasonably expected” TDRs, which are identified by the Company as a loan expected to be classified as a TDR within the next six months. Management judgment is utilized to make this determination. 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 (or release) for 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 - Upon adoption of ASC 326, the Company made the following elections regarding accrued interest receivable: • 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 our 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, except for situations where principal and interest is considered collectible such as a loan with a guarantee. 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 becoming a TDR 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. If a loan is on accrual status before it becomes a TDR, and management concludes that full repayment is probable based on internal evaluation, it will remain on accrual status following restructuring. If the restructured consumer loan does not perform, it is placed on non-accrual status when it is 90 days delinquent. 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 $4,295,025,000 and $3,804,444,000 at March 31, 2022 and September 30, 2021, respectively. The reserve for unfunded commitments is recognized as a liability (included as other liabilities in "Accrued expenses and 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	6 Months Ended
	Mar. 31, 2022
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848). The amendments in this ASU provide temporary, optional guidance to ease the potential burden in accounting for reference rate reform. The ASU provides optional expedients and exceptions for applying GAAP to transactions affected by the anticipated transition away from LIBOR if certain criteria are met. The ASU primarily includes relief related to contract modifications and hedging relationships, as well as providing a one-time election for the sale or transfer of debt securities classified as held-to-maturity. This guidance is effective immediately and the amendments may be applied prospectively through December 31, 2022. The Company has evaluated the regulatory requirements to cease the use of LIBOR and has put in place systems and capabilities for this purpose. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging (Topic 815) . The amendments in this ASU clarify the guidance on ASC 815 on fair value hedge accounting of interest rate risk for portfolios and financial assets. Among other things, the amended guidance establishes the "last-of-layer" method for making the fair value hedge accounting for these portfolios more accessible and renames that method the "portfolio layer" method. The amendments in this ASU are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. We do not expect the amendments to have a material effect on our consolidated financial statements. In March 2022, the FASB issued ASU 2022-02, Financial Instruments - Credit Losses (Topic 326) . The amendments in this ASU eliminate the guidance on troubled debt restructurings while enhancing disclosure requirements for certain loan refinancing and restructurings by creditors made to borrowers experiencing financial difficulties. The ASU also requires that entities disclose current-period gross charge-offs by year of origination for loans and leases. The amendments in this ASU are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. We do not expect the amendments to have a material effect on our consolidated financial statements.

Dividends and Share Repurchases

Dividends and Share Repurchases	6 Months Ended
	Mar. 31, 2022
Stockholders' Equity Note [Abstract]
Dividends and Share Repurchases	Dividends and Share Repurchases On February 18, 2022, the Company paid a regular dividend on common stock of $0.24 per share, which represented the 156 th consecutive quarterly cash dividend. Dividends per share were $0.24 and $0.23 for the quarters ended March 31, 2022 and 2021, respectively. For the three months ended March 31, 2022, the Company repurchased 4,684 shares at an average price of $34.65. As of March 31, 2022, there are 3,728,320 remaining shares authorized to be repurchased under the current Board approved share repurchase program. The Company pays a cash dividend, if declared by the Board, of $12.1875 per share on its Series A Preferred Stock quarterly on January 15, April 15, July 15 and October 15. This dividend equals $0.30468750 per depositary share (each dividend, a "Series A Preferred Dividend"). The Company paid the Series A Preferred Dividend on April 15, 2022.

Loans Receivable

Loans Receivable	6 Months Ended
	Mar. 31, 2022
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. March 31, 2022 September 30, 2021 (In thousands) (In thousands) Commercial loans Multi-family $ 2,392,810 13.5 % $ 2,291,477 14.0 % Commercial real estate 2,829,946 15.9 2,443,845 15.0 Commercial & industrial (1) 2,504,442 14.1 2,314,654 14.2 Construction 3,136,239 17.6 2,888,214 17.7 Land - acquisition & development 236,313 1.3 222,457 1.4 Total commercial loans 11,099,750 62.4 10,160,647 62.3 Consumer loans Single-family residential 5,442,535 30.6 4,951,627 30.4 Construction - custom 836,314 4.7 783,221 4.8 Land - consumer lot loans 154,976 0.9 149,956 0.9 HELOC 174,367 1.0 165,989 1.0 Consumer 67,511 0.4 87,892 0.5 Total consumer loans 6,675,703 37.6 6,138,685 37.7 Total gross loans 17,775,453 100 % 16,299,332 100 % Less: Allowance for credit losses on loans 171,384 171,300 Loans in process 2,440,430 2,232,836 Net deferred fees, costs and discounts 68,713 61,626 Total loan contra accounts 2,680,527 2,465,762 Net loans $ 15,094,926 $ 13,833,570 (1) Includes $111 million and $312 million of Small Business Administration’s Paycheck Protection Program ("PPP") loans as of March 31, 2022 and September 30, 2021, respectively. The Company elected to exclude accrued interest receivable ("AIR") from the amortized cost basis of loans for disclosure purposes and from the calculations of estimated credit losses. As of March 31, 2022, and September 30, 2021, AIR for loans totaled $47,216,000 and $46,234,000, 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 $7,325,383,000 and $5,930,015,000 at March 31, 2022 and September 30, 2021, respectively, were pledged to secure borrowings from the Federal Home Loan Bank ("FHLB") as part of our 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. March 31, 2022 September 30, 2021 (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 $ — $ — $ — $ 475 $ — $ — Commercial real estate 6,412 — — 8,038 — — Commercial & industrial 4,789 1,215 9,996 365 30 — Construction 343 — — 505 — — Land - acquisition & development 2,340 — — 2,340 — — Total commercial loans 13,884 1,215 9,996 11,723 30 — Consumer loans Single-family residential 18,612 — — 19,320 — — Construction - custom 465 — — — — — Land - consumer lot loans 310 — — 359 — — HELOC 329 — — 287 — — Consumer 39 — — 60 — — Total consumer loans 19,755 — — 20,026 — — Total non-accrual loans $ 33,639 $ 1,215 $ 9,996 $ 31,749 $ 30 $ — % of total loans 0.22 % 0.23 % The Company recognized interest income on non-accrual loans of approximately $1,733,000 in the six months ended March 31, 2022. 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 $631,000 for the six months ended March 31, 2022. Recognized interest income for the six months ended March 31, 2022 was higher than what otherwise would have been recognized in the period due to the collection of past due amounts. 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. March 31, 2022 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 $ 2,377,657 $ 2,377,347 $ 310 $ — $ — $ 310 0.01 % Commercial real estate 2,808,628 2,804,726 2,213 — 1,689 3,902 0.14 Commercial & industrial 2,497,008 2,481,463 4,052 51 11,442 15,545 0.62 Construction 1,212,103 1,212,103 — — — — — Land - acquisition & development 211,061 208,721 — — 2,340 2,340 1.11 Total commercial loans 9,106,457 9,084,360 6,575 51 15,471 22,097 0.24 Consumer Loans Single-family residential 5,418,645 5,397,381 3,285 2,785 15,194 21,264 0.39 Construction - custom 344,113 343,213 435 — 465 900 0.26 Land - consumer lot loans 153,549 153,172 67 19 291 377 0.25 HELOC 175,929 175,257 347 15 310 672 0.38 Consumer 67,617 67,521 54 7 35 96 0.14 Total consumer loans 6,159,853 6,136,544 4,188 2,826 16,295 23,309 0.38 Total Loans $ 15,266,310 $ 15,220,904 $ 10,763 $ 2,877 $ 31,766 $ 45,406 0.30 % Delinquency % 99.70% 0.07% 0.02% 0.21% 0.30% September 30, 2021 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 $ 2,273,689 $ 2,273,214 $ — $ — $ 475 $ 475 0.02 % Commercial real estate 2,429,332 2,428,014 971 64 283 1,318 0.05 Commercial & industrial 2,303,927 2,303,605 — — 322 322 0.01 Construction 1,117,227 1,117,186 — — 41 41 — Land - acquisition & development 192,416 190,076 — — 2,340 2,340 1.22 Total commercial loans 8,316,591 8,312,095 971 64 3,461 4,496 0.05 Consumer Loans Single-family residential 4,937,064 4,915,749 3,627 2,165 15,523 21,315 0.43 Construction - custom 347,752 347,752 — — — — — Land - consumer lot loans 148,534 147,952 5 307 270 582 0.39 HELOC 166,940 166,627 47 — 266 313 0.19 Consumer 87,989 87,727 152 59 51 262 0.30 Total consumer loans 5,688,279 5,665,807 3,831 2,531 16,110 22,472 0.40 Total Loans $ 14,004,870 $ 13,977,902 $ 4,802 $ 2,595 $ 19,571 $ 26,968 0.19 % Delinquency % 99.81% 0.03% 0.02% 0.14% 0.19% Most TDRs are accruing and performing loans where the borrower has proactively approached the Company about modification due to temporary financial difficulties. Each request for modification is individually evaluated for merit and likelihood of success. The concession granted in a loan modification is typically a payment reduction through a rate reduction of between 100 to 200 basis points for a specific term, usually six We evaluate the credit quality of our 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 March 31, 2022. Term Loans Amortized Cost Basis by Origination Year YTD 2022 2021 2020 2019 2018 Prior to 2018 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 401,130 $ 747,291 $ 423,091 $ 143,051 $ 197,750 $ 440,126 $ 21,235 $ — $ 2,373,674 Special Mention — — 1,745 — — — — — 1,745 Substandard — — — — 649 1,589 — — 2,238 Total $ 401,130 $ 747,291 $ 424,836 $ 143,051 $ 198,399 $ 441,715 $ 21,235 $ — $ 2,377,657 Commercial real estate Pass $ 438,223 $ 665,379 $ 412,828 $ 289,728 $ 261,937 $ 571,942 $ 2,974 $ — $ 2,643,011 Special Mention — — — 25,548 32,952 10,388 — — 68,888 Substandard — — 8,253 42,150 931 44,309 1,086 — 96,729 Total $ 438,223 $ 665,379 $ 421,081 $ 357,426 $ 295,820 $ 626,639 $ 4,060 $ — $ 2,808,628 Commercial & industrial Pass $ 166,005 $ 535,738 $ 169,933 $ 45,916 $ 28,461 $ 237,637 $ 1,163,539 $ 84 $ 2,347,313 Special Mention 3,454 — 2,749 5,785 — — 35,150 — 47,138 Substandard — 13,447 21,901 86 4,492 2,059 60,572 — 102,557 Total $ 169,459 $ 549,185 $ 194,583 $ 51,787 $ 32,953 $ 239,696 $ 1,259,261 $ 84 $ 2,497,008 Construction Pass $ 243,483 $ 517,206 $ 305,966 $ 58,463 $ 374 $ 16,314 $ 67,769 $ — $ 1,209,575 Special Mention — 2,185 — — — — — — 2,185 Substandard — — 343 — — — — — 343 Total $ 243,483 $ 519,391 $ 306,309 $ 58,463 $ 374 $ 16,314 $ 67,769 $ — $ 1,212,103 Land - acquisition & development Pass $ 44,638 $ 79,721 $ 29,947 $ 10,865 $ 11,835 $ 29,115 $ 2,600 $ — $ 208,721 Substandard — — — — — 2,340 — — 2,340 Total $ 44,638 $ 79,721 $ 29,947 $ 10,865 $ 11,835 $ 31,455 $ 2,600 $ — $ 211,061 Total commercial loans Pass $ 1,293,479 $ 2,545,335 $ 1,341,765 $ 548,023 $ 500,357 $ 1,295,134 $ 1,258,117 $ 84 $ 8,782,294 Special Mention 3,454 2,185 4,494 31,333 32,952 10,388 35,150 — 119,956 Substandard — 13,447 30,497 42,236 6,072 50,297 61,658 — 204,207 Total $ 1,296,933 $ 2,560,967 $ 1,376,756 $ 621,592 $ 539,381 $ 1,355,819 $ 1,354,925 $ 84 $ 9,106,457 Term Loans Amortized Cost Basis by Origination Year YTD 2022 2021 2020 2019 2018 Prior to 2018 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 767,151 $ 1,479,568 $ 790,997 $ 349,688 $ 298,259 $ 1,711,718 $ — $ — $ 5,397,381 30 days past due — 219 — — — 3,066 — — 3,285 60 days past due — — 387 361 — 2,037 — — 2,785 90+ days past due — — — 342 169 14,683 — — 15,194 Total $ 767,151 $ 1,479,787 $ 791,384 $ 350,391 $ 298,428 $ 1,731,504 $ — $ — $ 5,418,645 Construction - custom Current $ 48,348 $ 255,534 $ 36,447 $ 2,184 $ 700 $ — $ — $ — $ 343,213 30 days past due — 435 — — — — — — 435 90+ days past due — — 465 — — — — — 465 Total $ 48,348 $ 255,969 $ 36,912 $ 2,184 $ 700 $ — $ — $ — $ 344,113 Land - consumer lot loans Current $ 34,562 $ 70,609 $ 21,962 $ 6,202 $ 3,727 $ 16,110 $ — $ — $ 153,172 30 days past due — — 51 — — 16 — — 67 60 days past due — — — — — 19 — — 19 90+ days past due — — 48 — — 243 — — 291 Total $ 34,562 $ 70,609 $ 22,061 $ 6,202 $ 3,727 $ 16,388 $ — $ — $ 153,549 HELOC Current $ — $ — $ — $ — $ — $ 5,154 $ 169,939 $ 164 $ 175,257 30 days past due — — — — — 150 89 108 347 60 days past due — — — — — 15 — — 15 90+ days past due — — — — — — 310 — 310 Total $ — $ — $ — $ — $ — $ 5,319 $ 170,338 $ 272 $ 175,929 Consumer Current $ 139 $ 10,325 $ 8,079 $ 366 $ 28,257 $ 8,495 $ 11,860 $ — $ 67,521 30 days past due — — — 6 — 47 1 — 54 60 days past due 2 — — — — 1 4 — 7 90+ days past due — — — 34 — 1 — — 35 Total $ 141 $ 10,325 $ 8,079 $ 406 $ 28,257 $ 8,544 $ 11,865 $ — $ 67,617 Total consumer loans Current $ 850,200 $ 1,816,036 $ 857,485 $ 358,440 $ 330,943 $ 1,741,477 $ 181,799 $ 164 $ 6,136,544 30 days past due — 654 51 6 — 3,279 90 108 4,188 60 days past due 2 — 387 361 — 2,072 4 — 2,826 90+ days past due — — 513 376 169 14,927 310 — 16,295 Total $ 850,202 $ 1,816,690 $ 858,436 $ 359,183 $ 331,112 $ 1,761,755 $ 182,203 $ 272 $ 6,159,853

Allowance for Losses on Loans

Allowance for Losses on Loans	6 Months Ended
	Mar. 31, 2022
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 March 31, 2022 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 15,993 $ — $ — $ (1,530) $ 14,463 Commercial real estate 25,722 — 753 (1,793) 24,682 Commercial & industrial 47,231 (873) 2 7,543 53,903 Construction 24,766 — 179 (2,238) 22,707 Land - acquisition & development 14,125 — 20 (460) 13,685 Total commercial loans 127,837 (873) 954 1,522 129,440 Consumer loans Single-family residential 30,106 — 147 (1,261) 28,992 Construction - custom 3,719 — — (590) 3,129 Land - consumer lot loans 4,984 — 40 81 5,105 HELOC 2,365 — 100 10 2,475 Consumer 2,400 (39) 144 (262) 2,243 Total consumer loans 43,574 (39) 431 (2,022) 41,944 Total loans $ 171,411 $ (912) $ 1,385 $ (500) $ 171,384 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $0. Three Months Ended March 31, 2021 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 14,363 $ — $ — $ 3,413 $ 17,776 Commercial real estate 23,496 — 1,457 1,869 26,822 Commercial & industrial 44,317 (18) 11 3,484 47,794 Construction 26,365 — — (3,816) 22,549 Land - acquisition & development 10,666 — 410 (573) 10,503 Total commercial loans 119,207 (18) 1,878 4,377 125,444 Consumer loans Single-family residential 38,613 (106) 497 (3,896) 35,108 Construction - custom 3,594 — — (346) 3,248 Land - consumer lot loans 2,958 — 7 327 3,292 HELOC 2,362 — — (136) 2,226 Consumer 3,455 (84) 290 (326) 3,335 Total consumer loans 50,982 (190) 794 (4,377) 47,209 Total loans $ 170,189 $ (208) $ 2,672 $ — $ 172,653 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $0. Six Months Ended March 31, 2022 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 16,949 $ — $ — $ (2,486) $ 14,463 Commercial real estate 23,437 (529) 797 977 24,682 Commercial & industrial 45,957 (916) 64 8,798 53,903 Construction 25,585 — 2,179 (5,057) 22,707 Land - acquisition & development 13,447 (2) 40 200 13,685 Total commercial loans 125,375 (1,447) 3,080 2,432 129,440 Consumer loans Single-family residential 30,978 — 552 (2,538) 28,992 Construction - custom 4,907 — — (1,778) 3,129 Land - consumer lot loans 4,939 (27) 45 148 5,105 HELOC 2,390 — 101 (16) 2,475 Consumer 2,711 (115) 395 (748) 2,243 Total consumer loans 45,925 (142) 1,093 (4,932) 41,944 Total loans $ 171,300 $ (1,589) $ 4,173 $ (2,500) $ 171,384 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $2.5 million. Six Months Ended March 31, 2021 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 13,853 $ — $ — $ 3,923 $ 17,776 Commercial real estate 22,516 — 2,246 2,060 26,822 Commercial & industrial 38,665 (20) 61 9,088 47,794 Construction 24,156 — — (1,607) 22,549 Land - acquisition & development 10,733 — 445 (675) 10,503 Total commercial loans 109,923 (20) 2,752 12,789 125,444 Consumer loans Single-family residential 45,186 (106) 1,276 (11,248) 35,108 Construction - custom 3,555 — — (307) 3,248 Land - consumer lot loans 2,729 — 14 549 3,292 HELOC 2,571 — — (345) 2,226 Consumer 2,991 (234) 516 62 3,335 Total consumer loans 57,032 (340) 1,806 (11,289) 47,209 Total loans $ 166,955 $ (360) $ 4,558 $ 1,500 $ 172,653 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $1.5 million. The Company recorded a $500,000 release of allowance for credit losses for the three months ended March 31, 2022, compared with no provision or release for the three months ended March 31, 2021. The release in the three months ended March 31, 2022 was primarily due to improvements in the credit quality of certain loan portfolios related to strong real estate markets and collateral conditions, mostly offset by growth in loans receivable. These same factors mostly offset and led to no provision or release being recorded for the three months ended March 31, 2021. The Company recorded no provision or release of allowance for credit losses for the six months ended March 31, 2022, compared with a $3,000,000 provision for credit losses for the six months ended March 31, 2021. Recoveries, net of charge-offs, totaled $473,000 for the three months ended March 31, 2022, compared to net recoveries of $2,464,000 during the three months ended March 31, 2021. Recoveries, net of charge-offs, totaled $2,584,000 for the six months ended March 31, 2022, compared to net recoveries of $4,198,000 during the six months ended March 31, 2021. No allowance was recorded as of March 31, 2022 or as of September 30, 2021 for the $109,746,000 and $305,162,000 of PPP loans in the portfolio on each date, respectively, which are included in the commercial & industrial loan category, due to the government guarantee. Non-performing assets were $47,243,000, or 0.23% of total assets, at March 31, 2022, compared to $43,625,000, or 0.22% of total assets, at September 30, 2021. Non-accrual loans were $33,639,000 at March 31, 2022, compared to $31,749,000 at September 30, 2021. Delinquencies, as a percent of total loans, were 0.30% at March 31, 2022, compared to 0.19% at September 30, 2021. 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 "Loans Receivable." The following tables provide the amortized cost of loans receivable based on risk rating categories as previously defined. March 31, 2022 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,373,674 $ 1,745 $ 2,238 $ — $ — $ 2,377,657 Commercial real estate 2,643,011 68,888 96,729 — — 2,808,628 Commercial & industrial 2,347,313 47,138 102,557 — — 2,497,008 Construction 1,209,575 2,185 343 — — 1,212,103 Land - acquisition & development 208,721 — 2,340 — — 211,061 Total commercial loans 8,782,294 119,956 204,207 — — 9,106,457 Consumer loans Single-family residential 5,396,628 — 22,017 — — 5,418,645 Construction - custom 343,648 — 465 — — 344,113 Land - consumer lot loans 153,240 — 309 — — 153,549 HELOC 175,600 — 329 — — 175,929 Consumer 67,601 — 16 — — 67,617 Total consumer loans 6,136,717 — 23,136 — — 6,159,853 Total $ 14,919,011 $ 119,956 $ 227,343 $ — $ — $ 15,266,310 Total grade as a % of total loans 97.72 % 0.79 % 1.49 % — % — % September 30, 2021 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,252,395 $ 4,874 $ 16,420 $ — $ — $ 2,273,689 Commercial real estate 2,174,386 57,625 197,321 — — 2,429,332 Commercial & industrial 2,108,152 48,124 147,651 — — 2,303,927 Construction 1,115,791 931 505 — — 1,117,227 Land - acquisition & development 190,076 — 2,340 — — 192,416 Total commercial loans 7,840,800 111,554 364,237 — — 8,316,591 Consumer loans Single-family residential 4,915,106 — 21,958 — — 4,937,064 Construction - custom 347,752 — — — — 347,752 Land - consumer lot loans 148,010 — 524 — — 148,534 HELOC 166,652 — 288 — — 166,940 Consumer 87,962 — 27 — — 87,989 Total consumer loans 5,665,482 — 22,797 — — 5,688,279 Total loans $ 13,506,282 $ 111,554 $ 387,034 $ — $ — $ 14,004,870 Total grade as a % of total loans 96.44 % 0.80 % 2.76 % — % — % The following tables provide information on amortized cost of loans receivable based on borrower payment activity. March 31, 2022 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,377,657 100.0 % $ — — % Commercial real estate 2,802,216 99.8 6,412 0.2 Commercial & industrial 2,492,219 99.8 4,789 0.2 Construction 1,211,760 100.0 343 0.0 Land - acquisition & development 208,721 98.9 2,340 1.1 Total commercial loans 9,092,573 99.8 13,884 0.2 Consumer loans Single-family residential 5,400,033 99.7 18,612 0.3 Construction - custom 343,648 99.9 465 0.1 Land - consumer lot loans 153,239 99.8 310 0.2 HELOC 175,600 99.8 329 0.2 Consumer 67,578 99.9 39 0.1 Total consumer loans 6,140,098 99.7 19,755 0.3 Total loans $ 15,232,671 99.8 % $ 33,639 0.2 % September 30, 2021 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,273,214 100.0 % $ 475 — % Commercial real estate 2,421,294 99.7 8,038 0.3 Commercial & industrial 2,303,562 100.0 365 — Construction 1,116,722 100.0 505 — Land - acquisition & development 190,076 98.8 2,340 1.2 Total commercial loans 8,304,868 99.9 11,723 0.1 Consumer loans Single-family residential 4,917,744 99.6 19,320 0.4 Construction - custom 347,752 100.0 — — Land - consumer lot loans 148,175 99.8 359 0.2 HELOC 166,653 99.8 287 0.2 Consumer 87,929 99.9 60 0.1 Total consumer loans 5,668,253 99.6 20,026 0.4 Total loans $ 13,973,121 99.8 % $ 31,749 0.2 %

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Mar. 31, 2022
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. March 31, 2022 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 49,809 $ — $ 49,809 Asset-backed securities — 889,426 — 889,426 Municipal bonds — 38,468 — 38,468 Corporate debt securities — 333,999 — 333,999 Mortgage-backed securities Agency pass-through certificates — 597,903 — 597,903 Total available-for-sale securities — 1,909,605 — 1,909,605 Client swap program hedges — 27,353 — 27,353 Mortgage loan fair value hedges — 19,281 — 19,281 Borrowings cash flow hedges — 105,211 — 105,211 Total financial assets $ — $ 2,061,450 $ — $ 2,061,450 Financial Liabilities Client swap program hedges $ — $ 27,353 $ — $ 27,353 Commercial loan fair value hedges — 38 — 38 Total financial liabilities $ — $ 27,391 $ — $ 27,391 September 30, 2021 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 61,779 $ — $ 61,779 Asset-backed securities — 1,078,681 1,078,681 Municipal bonds — 39,984 — 39,984 Corporate debt securities — 350,988 — 350,988 Mortgage-backed securities Agency pass-through certificates — 606,827 — 606,827 Total available-for-sale securities — 2,138,259 — 2,138,259 Client swap program hedges — 10,983 — 10,983 Borrowings cash flow hedges — 42,442 — 42,442 Total financial assets $ — $ 2,191,684 $ — $ 2,191,684 Financial Liabilities Client swap program hedges $ — $ 10,983 $ — $ 10,983 Commercial loan fair value hedges — 2,177 — 2,177 Mortgage loan fair value hedges 1,641 1,641 Total financial liabilities $ — $ 14,801 $ — $ 14,801 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 March 31, 2022 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 March 31, 2022 and March 31, 2021, 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. March 31, 2022 Three Months Ended March 31, 2022 Six Months Ended March 31, 2022 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ 3,816 $ 3,816 $ (896) $ (985) Real estate owned (2) — — 1,571 1,571 32 (472) Balance at end of period $ — $ — $ 5,387 $ 5,387 $ (864) $ (1,457) (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. March 31, 2021 Three Months Ended March 31, 2021 Six Months Ended March 31, 2021 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ — $ — $ (25) $ (69) Real estate owned (2) — — 722 722 148 101 Balance at end of period $ — $ — $ 722 $ 722 $ 123 $ 32 (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 March 31, 2022, there was $166,000 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 $4,780,000. Fair Values of Financial Instruments FASB ASC 825, Financial Instruments ("ASC 825") requires disclosure of fair value information about financial instruments, whether or not recognized on the statement of financial condition, for which it is practicable to estimate those values. Certain financial instruments and all non-financial instruments are excluded from the disclosure requirements. Accordingly, the aggregate fair value estimates presented do not reflect the underlying fair value of the Company. Although management is not aware of any factors that would materially affect the estimated fair value amounts presented below, such amounts have not been comprehensively revalued for purposes of these financial statements since the dates shown, and therefore, estimates of fair value subsequent to those dates may differ significantly from the amounts presented below. March 31, 2022 September 30, 2021 Level in Fair Value Hierarchy Carrying Estimated Carrying Estimated ($ in thousands) Financial assets Cash and cash equivalents 1 $ 1,947,504 $ 1,947,504 $ 2,090,809 $ 2,090,809 Available-for-sale securities U.S. government and agency securities 2 49,809 49,809 61,779 61,779 Asset-backed securities 2 889,426 889,426 1,078,681 1,078,681 Municipal bonds 2 38,468 38,468 39,984 39,984 Corporate debt securities 2 333,999 333,999 350,988 350,988 Mortgage-backed securities Agency pass-through certificates 2 597,903 597,903 606,827 606,827 Total available-for-sale securities 1,909,605 1,909,605 2,138,259 2,138,259 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 2 301,221 294,354 366,025 379,547 Total held-to-maturity securities 301,221 294,354 366,025 379,547 Loans receivable 3 15,094,926 15,189,282 13,833,570 14,279,725 FHLB and FRB stock 2 78,873 78,873 102,863 102,863 Other assets - client swap program hedges 2 27,353 27,353 10,983 10,983 Other assets - mortgage loan fair value hedges 2 19,281 19,281 — — Other assets - borrowings cash flow hedges 2 105,211 105,211 42,442 42,442 Financial liabilities Time deposits 2 3,251,042 3,199,750 3,434,087 3,382,206 FHLB advances 2 1,720,000 1,601,795 1,720,000 1,692,412 Other liabilities - client swap program hedges 2 27,353 27,353 10,983 10,983 Other liabilities - commercial loan fair value hedges 2 38 38 2,177 2,177 Other liabilities - mortgage loan fair value hedges 2 — — 1,641 1,641 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 (AFS) securities and held-to-maturity (HTM) 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 and FRB 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. FHLB advances – The fair value of FHLB advances and other 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. March 31, 2022 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due 1 to 5 years $ 50,441 $ 27 $ (659) $ 49,809 1.07 % Asset-backed securities 1 to 5 years 18,908 — (602) 18,306 1.08 5 to 10 years 62,883 121 (202) 62,802 0.79 Over 10 years 807,611 2,144 (1,437) 808,318 1.28 Corporate debt securities due 1 to 5 years 226,170 2,301 — 228,471 1.79 5 to 10 years 115,010 — (9,482) 105,528 3.87 Municipal bonds due Within 1 year 1,509 3 — 1,512 — 5 to 10 years 5,766 — (156) 5,610 0.16 Over 10 years 29,890 1,456 — 31,346 5.85 Mortgage-backed securities Agency pass-through certificates 603,800 4,936 (10,833) 597,903 2.60 1,921,988 10,988 (23,371) 1,909,605 1.95 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 301,221 170 (7,037) 294,354 3.16 301,221 170 (7,037) 294,354 3.16 $ 2,223,209 $ 11,158 $ (30,408) $ 2,203,959 2.11 % September 30, 2021 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due 1 to 5 years $ 47,339 $ 240 $ — $ 47,579 0.44 % 5 to 10 years 14,064 136 — 14,200 2.05 Asset-backed securities 1 to 5 years 19,730 — (434) 19,296 0.52 5 to 10 years 71,207 412 (97) 71,522 0.57 Over 10 years 973,892 14,069 (98) 987,863 0.94 Corporate debt securities due Within 1 year 225,928 7,860 — 233,788 1.57 1 to 5 years 86,802 1,345 — 88,147 4.64 5 to 10 years 28,804 249 — 29,053 1.95 Municipal bonds due Within 1 year 1,493 17 — 1,510 — 5 to 10 years 5,781 294 — 6,075 0.22 Over 10 years 29,909 2,490 — 32,399 5.85 Mortgage-backed securities Agency pass-through certificates 585,121 23,717 (2,011) 606,827 2.60 2,090,070 50,829 (2,640) 2,138,259 1.69 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 366,025 13,522 — 379,547 3.17 366,025 13,522 — 379,547 3.17 $ 2,456,095 $ 64,351 $ (2,640) $ 2,517,806 1.89 % For available-for-sale investment securities, there were purchases of $124,651,000 during the six months ended March 31, 2022 and purchases of $522,454,000 during the six months ended March 31, 2021. There were $4,510,000 of sales of available-for-sale investment securities during the six months ended March 31, 2022 and no sales during the prior year same period. For held-to-maturity investment securities, there were no purchases during the six months ended March 31, 2022 and no purchases during the six months ended March 31, 2021. There were no sales of held-to-maturity investment securities during the six months ended March 31, 2022 or March 31, 2021. Substantially all of the agency mortgage-backed securities have contractual due dates that exceed 10 years. The Company elected to exclude AIR from the amortized cost basis of debt securities disclosed throughout this footnote. For AFS securities, AIR totaled $3,448,000 and $3,458,000 as of March 31, 2022 and September 30, 2021, respectively. For HTM debt securities, AIR totaled $776,000 and $944,000 as of March 31, 2022 and September 30, 2021, 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 March 31, 2022 and September 30, 2021, by length of time that individual securities in each category have been in a continuous loss position. There were 131 and 31 securities with an unrealized loss as of March 31, 2022 and September 30, 2021, respectively. The decline in fair value since purchase is attributable to changes in interest rates. Because the Company does not intend to sell these securities and does not consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company does not consider these investments to have any credit impairment. March 31, 2022 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Corporate debt securities $ — $ — $ (9,482) $ 105,528 $ (9,482) $ 105,528 Municipal bonds (156) 5,610 — — (156) 5,610 U.S. government and agency securities (659) 34,697 — — (659) 34,697 Asset-backed securities (1,269) 277,125 (972) 67,792 (2,241) 344,917 Mortgage-backed securities (5,583) 234,166 (5,250) 63,445 (10,833) 297,611 (7,667) 551,598 (15,704) 236,765 (23,371) 788,363 Held-to-maturity securities Mortgage-backed securities (7,037) 291,911 — — (7,037) 291,911 $ (14,704) $ 843,509 $ (15,704) $ 236,765 $ (30,408) $ 1,080,274 September 30, 2021 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Asset-backed securities $ (15) $ 4,639 $ (614) $ 70,058 $ (629) $ 74,697 Mortgage-backed securities (1,569) 47,758 (442) 32,266 (2,011) 80,024 (1,584) 52,397 (1,056) 102,324 (2,640) 154,721 Held-to-maturity securities Mortgage-backed securities — — — — — — $ (1,584) $ 52,397 $ (1,056) $ 102,324 $ (2,640) $ 154,721 Substantially all of the Company’s held-to-maturity 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 March 31, 2022 or September 30, 2021. The Company does not believe that the available-for-sale debt securities that were in an unrealized loss position have any credit loss impairment as of March 31, 2022 or September 30, 2021. The Company does not intend to sell the investment securities that were in an unrealized loss position and it is not more likely than not that the Company will be required to sell the investment securities before recovery of their amortized cost basis, which may be at maturity. Available-for-sale 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 (rated AA or higher) 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	6 Months Ended
	Mar. 31, 2022
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 March 31, 2022 and September 30, 2021. March 31, 2022 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 $ 615,830 $ 27,353 Other liabilities $ 615,830 $ 27,353 Commercial loan fair value hedges Other assets — — Other liabilities 42,209 38 Mortgage loan fair value hedges Other assets 470,000 19,281 Other liabilities — — Borrowings cash flow hedges Other assets 1,000,000 105,211 Other liabilities — — $ 2,085,830 $ 151,845 $ 658,039 $ 27,391 September 30, 2021 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 $ 644,355 $ 10,983 Other liabilities $ 644,355 $ 10,983 Commercial loan fair value hedges Other assets — — Other liabilities 44,678 2,177 Mortgage loan fair value hedges Other assets — — Other liabilities 470,000 1,641 Borrowings cash flow hedges Other assets 1,000,000 42,442 Other liabilities — — $ 1,644,355 $ 53,425 $ 1,159,033 $ 14,801 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 "last of 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 March 31, 2022 and September 30, 2021. (In thousands) March 31, 2022 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) $ 1,272,018 $ (18,845) $ 1,272,018 $ (18,845) (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 March 31, 2022, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $1,230 million, the cumulative basis adjustment associated with the hedging relationships was $(19) million, and the amount of the designated hedged items was $470 million. During the year ended September 30, 2021, hedge accounting was discontinued on $30 million (30%) of a $100 million last of layer hedge. At March 31, 2022, there is $1.0 million of remaining unamortized basis adjustment associated with the terminated portion of the hedge and it will be recognized over the remaining life of the associated pool of loans. (2) Includes the amortized cost basis of commercial loans designated in fair value hedging relationships. At March 31, 2022, the amortized cost basis of the hedged commercial loans was $42 million and the cumulative basis adjustment associated with the hedging relationships was $0.1 million. (In thousands) September 30, 2021 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) $ 1,515,487 $ 4,215 $ 1,515,487 $ 4,215 (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, 2021, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $1,469 million, the cumulative basis adjustment associated with the hedging relationships was $1.9 million million, and the amount of the designated hedged items was $470 million. During the year ended September 30, 2021, hedge accounting was discontinued on $30 million (30%) of a $100 million last of layer hedge. (2) Includes the amortized cost basis of commercial loans designated in fair value hedging relationships. At September 30, 2021, the amortized cost basis of the hedged commercial loans was $47 million and the cumulative basis adjustment associated with the hedging relationships was $2.4 million. During the year ended September 30, 2021, hedge accounting was discontinued on a $46 million commercial loan hedge. 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. During the six months ended March 31, 2021, $200,000,000 of cash flow hedges with an average effective rate of 1.37% were terminated and the associated FHLB borrowings were repaid at their 90-day call date. Additionally, a $200,000,000 partial termination of a cash flow hedge with an average effective rate of 0.79% was executed with the associated FHLB borrowing being repaid and a $14,110,000 gain recorded on the swap. Lastly, a $150,000,000 FHLB borrowing (unhedged) with a rate of 2.91% was repaid prior to maturity. As of March 31, 2022, the maturities for hedges of adjustable rate borrowings ranged from two years to eight years, with the weighted average being 7.0 years. The following tables present the gain (loss) recognized in AOCI on derivative instruments related to cash flow hedges on borrowings for the periods presented, as well as the effect of reclassification adjustments. (In thousands) Three Months Ended March 31, Amounts recognized in AOCI 2022 2021 Interest rate contracts: Pay fixed/receive floating swaps on borrowings cash flow hedges $ 56,323 $ 70,565 Reclassification adjustment of net (gain)/loss included in net income — (14,110) Total pre-tax gain/(loss) recognized in AOCI $ 56,323 $ 56,455 (In thousands) Six Months Ended March 31, Amounts recognized in AOCI 2022 2021 Interest rate contracts: Pay fixed/receive floating swaps on borrowings cash flow hedges $ 62,769 $ 90,683 Reclassification adjustment of net (gain)/loss included in net income — (14,110) Total pre-tax gain/(loss) recognized in AOCI $ 62,769 $ 76,573 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 March 31, 2022 Three Months Ended March 31, 2021 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 $ 139,260 $ (7,525) $ 132,757 $ (11,991) Gain/(loss) on fair value hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ (1,199) $ (1,563) Recognized on derivatives 18,561 17,491 Recognized on hedged items (18,586) (17,377) Net income/(expense) recognized on fair value hedges $ (1,224) $ (1,449) Gain/(loss) on cash flow hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 1,715 $ 3,066 Amount of derivative gain/(loss) reclassified from AOCI into interest income/expense — 14,110 Net income/(expense) recognized on cash flow hedges $ 1,715 $ 17,176 Six Months Ended March 31, 2022 Six Months Ended March 31, 2021 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 $ 277,769 $ (15,368) $ 266,428 $ (25,189) Gain/(loss) on fair value hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ (2,570) $ (3,104) Recognized on derivatives 23,061 22,078 Recognized on hedged items (23,061) (21,833) Net income/(expense) recognized on fair value hedges $ (2,570) $ (2,859) Gain/(loss) on cash flow hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 3,736 $ 6,664 Amount of derivative gain/(loss) reclassified from AOCI into interest income/expense — 14,110 Net income/(expense) recognized on cash flow hedges $ 3,736 $ 20,774 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. There was no net impact to the statement of operations for the six months ended March 31, 2022 and 2021 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 March 31, Derivative instruments Classification of gain/(loss) recognized in income on derivative instrument 2022 2021 Interest rate contracts: Pay fixed/receive floating swap Other noninterest income $ 33,298 $ 40,929 Receive fixed/pay floating swap Other noninterest income (33,298) (40,929) $ — $ —

Revenue from Contracts with Cus

Revenue from Contracts with Customers	6 Months Ended
	Mar. 31, 2022
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 our 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 6.0% of our total revenues for the six months ended March 31, 2022, compared to 5.7% for the six months ended March 31, 2021. As this standard is immaterial to our 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).

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Mar. 31, 2022
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 2022 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 loans in process and unused lines of credit, which had a combined balance of $4,295,025,000 and $3,804,444,000 at March 31, 2022 and September 30, 2021, respectively. The reserve was $30,000,000 as of March 31, 2022, which is an increase from $27,500,000 at September 30, 2021. 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.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Mar. 31, 2022
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 in the Company's 2021 Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") on November 19, 2021 ("2021 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. Investments in equity securities with readily determinable fair values (marketable) are measured at fair value, with changes in the fair value recognized as a component of Other income in the Consolidated Statements of Operations. Investments in equity investments that do not have readily determinable fair values (non-marketable) are accounted for at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the
Allowance for Credit Losses (Loans Receivable)	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 CECL methodology requires an estimate of the credit losses expected over the life of an exposure (or pool of exposures) and replaces the incurred loss methodology’s threshold that delayed the recognition of a credit loss until it was probable a loss event was incurred. 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 most of our 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. When management deems it to be appropriate, the Company establishes a specific reserve for individually evaluated loans that do not share similar risk characteristics with the loans included in each respective loan pool. These individually evaluated loans
Allowance for Credit Losses (Held-to-Maturity and Available-for-Sale Debt Securities)	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.
Accrued Interest Receivable	Accrued Interest Receivable - Upon adoption of ASC 326, the Company made the following elections regarding accrued interest receivable: • 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 our 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, except for situations where principal and interest is considered collectible such as a loan with a guarantee. 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 becoming a TDR 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. If a loan is on accrual status before it becomes a TDR, and management concludes that full repayment is probable based on internal evaluation, it will remain on accrual status following restructuring. If the restructured consumer loan does not perform, it is placed on non-accrual status when it is 90 days delinquent. 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	Off-balance-sheet credit exposures - The only material off-balance-sheet credit exposures are unfunded loan commitments, which had a combined balance of $4,295,025,000 and $3,804,444,000 at March 31, 2022 and September 30, 2021, respectively. The reserve for unfunded commitments is recognized as a liability (included as other liabilities in "Accrued expenses and 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	In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848). The amendments in this ASU provide temporary, optional guidance to ease the potential burden in accounting for reference rate reform. The ASU provides optional expedients and exceptions for applying GAAP to transactions affected by the anticipated transition away from LIBOR if certain criteria are met. The ASU primarily includes relief related to contract modifications and hedging relationships, as well as providing a one-time election for the sale or transfer of debt securities classified as held-to-maturity. This guidance is effective immediately and the amendments may be applied prospectively through December 31, 2022. The Company has evaluated the regulatory requirements to cease the use of LIBOR and has put in place systems and capabilities for this purpose. The adoption of this ASU is not expected to have a material impact on the Company's consolidated financial statements. In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging (Topic 815) . The amendments in this ASU clarify the guidance on ASC 815 on fair value hedge accounting of interest rate risk for portfolios and financial assets. Among other things, the amended guidance establishes the "last-of-layer" method for making the fair value hedge accounting for these portfolios more accessible and renames that method the "portfolio layer" method. The amendments in this ASU are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. We do not expect the amendments to have a material effect on our consolidated financial statements. In March 2022, the FASB issued ASU 2022-02, Financial Instruments - Credit Losses (Topic 326) . The amendments in this ASU eliminate the guidance on troubled debt restructurings while enhancing disclosure requirements for certain loan refinancing and restructurings by creditors made to borrowers experiencing financial difficulties. The ASU also requires that entities disclose current-period gross charge-offs by year of origination for loans and leases. The amendments in this ASU are effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. We do not expect the amendments to have a material effect on our consolidated financial statements.
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)	6 Months Ended
	Mar. 31, 2022
Receivables [Abstract]
Schedule of Loans Receivable	The following table is a summary of loans receivable by loan portfolio segment and class. March 31, 2022 September 30, 2021 (In thousands) (In thousands) Commercial loans Multi-family $ 2,392,810 13.5 % $ 2,291,477 14.0 % Commercial real estate 2,829,946 15.9 2,443,845 15.0 Commercial & industrial (1) 2,504,442 14.1 2,314,654 14.2 Construction 3,136,239 17.6 2,888,214 17.7 Land - acquisition & development 236,313 1.3 222,457 1.4 Total commercial loans 11,099,750 62.4 10,160,647 62.3 Consumer loans Single-family residential 5,442,535 30.6 4,951,627 30.4 Construction - custom 836,314 4.7 783,221 4.8 Land - consumer lot loans 154,976 0.9 149,956 0.9 HELOC 174,367 1.0 165,989 1.0 Consumer 67,511 0.4 87,892 0.5 Total consumer loans 6,675,703 37.6 6,138,685 37.7 Total gross loans 17,775,453 100 % 16,299,332 100 % Less: Allowance for credit losses on loans 171,384 171,300 Loans in process 2,440,430 2,232,836 Net deferred fees, costs and discounts 68,713 61,626 Total loan contra accounts 2,680,527 2,465,762 Net loans $ 15,094,926 $ 13,833,570 (1) Includes $111 million and $312 million of Small Business Administration’s Paycheck Protection Program ("PPP") loans as of March 31, 2022 and September 30, 2021, respectively.
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. March 31, 2022 September 30, 2021 (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 $ — $ — $ — $ 475 $ — $ — Commercial real estate 6,412 — — 8,038 — — Commercial & industrial 4,789 1,215 9,996 365 30 — Construction 343 — — 505 — — Land - acquisition & development 2,340 — — 2,340 — — Total commercial loans 13,884 1,215 9,996 11,723 30 — Consumer loans Single-family residential 18,612 — — 19,320 — — Construction - custom 465 — — — — — Land - consumer lot loans 310 — — 359 — — HELOC 329 — — 287 — — Consumer 39 — — 60 — — Total consumer loans 19,755 — — 20,026 — — Total non-accrual loans $ 33,639 $ 1,215 $ 9,996 $ 31,749 $ 30 $ — % of total loans 0.22 % 0.23 %
Loan Delinquencies by Loan Portfolio and Class	The following tables provide details regarding loan delinquencies by loan portfolio and class. March 31, 2022 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 $ 2,377,657 $ 2,377,347 $ 310 $ — $ — $ 310 0.01 % Commercial real estate 2,808,628 2,804,726 2,213 — 1,689 3,902 0.14 Commercial & industrial 2,497,008 2,481,463 4,052 51 11,442 15,545 0.62 Construction 1,212,103 1,212,103 — — — — — Land - acquisition & development 211,061 208,721 — — 2,340 2,340 1.11 Total commercial loans 9,106,457 9,084,360 6,575 51 15,471 22,097 0.24 Consumer Loans Single-family residential 5,418,645 5,397,381 3,285 2,785 15,194 21,264 0.39 Construction - custom 344,113 343,213 435 — 465 900 0.26 Land - consumer lot loans 153,549 153,172 67 19 291 377 0.25 HELOC 175,929 175,257 347 15 310 672 0.38 Consumer 67,617 67,521 54 7 35 96 0.14 Total consumer loans 6,159,853 6,136,544 4,188 2,826 16,295 23,309 0.38 Total Loans $ 15,266,310 $ 15,220,904 $ 10,763 $ 2,877 $ 31,766 $ 45,406 0.30 % Delinquency % 99.70% 0.07% 0.02% 0.21% 0.30% September 30, 2021 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 $ 2,273,689 $ 2,273,214 $ — $ — $ 475 $ 475 0.02 % Commercial real estate 2,429,332 2,428,014 971 64 283 1,318 0.05 Commercial & industrial 2,303,927 2,303,605 — — 322 322 0.01 Construction 1,117,227 1,117,186 — — 41 41 — Land - acquisition & development 192,416 190,076 — — 2,340 2,340 1.22 Total commercial loans 8,316,591 8,312,095 971 64 3,461 4,496 0.05 Consumer Loans Single-family residential 4,937,064 4,915,749 3,627 2,165 15,523 21,315 0.43 Construction - custom 347,752 347,752 — — — — — Land - consumer lot loans 148,534 147,952 5 307 270 582 0.39 HELOC 166,940 166,627 47 — 266 313 0.19 Consumer 87,989 87,727 152 59 51 262 0.30 Total consumer loans 5,688,279 5,665,807 3,831 2,531 16,110 22,472 0.40 Total Loans $ 14,004,870 $ 13,977,902 $ 4,802 $ 2,595 $ 19,571 $ 26,968 0.19 % Delinquency % 99.81% 0.03% 0.02% 0.14% 0.19%
Summary 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 March 31, 2022. Term Loans Amortized Cost Basis by Origination Year YTD 2022 2021 2020 2019 2018 Prior to 2018 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 401,130 $ 747,291 $ 423,091 $ 143,051 $ 197,750 $ 440,126 $ 21,235 $ — $ 2,373,674 Special Mention — — 1,745 — — — — — 1,745 Substandard — — — — 649 1,589 — — 2,238 Total $ 401,130 $ 747,291 $ 424,836 $ 143,051 $ 198,399 $ 441,715 $ 21,235 $ — $ 2,377,657 Commercial real estate Pass $ 438,223 $ 665,379 $ 412,828 $ 289,728 $ 261,937 $ 571,942 $ 2,974 $ — $ 2,643,011 Special Mention — — — 25,548 32,952 10,388 — — 68,888 Substandard — — 8,253 42,150 931 44,309 1,086 — 96,729 Total $ 438,223 $ 665,379 $ 421,081 $ 357,426 $ 295,820 $ 626,639 $ 4,060 $ — $ 2,808,628 Commercial & industrial Pass $ 166,005 $ 535,738 $ 169,933 $ 45,916 $ 28,461 $ 237,637 $ 1,163,539 $ 84 $ 2,347,313 Special Mention 3,454 — 2,749 5,785 — — 35,150 — 47,138 Substandard — 13,447 21,901 86 4,492 2,059 60,572 — 102,557 Total $ 169,459 $ 549,185 $ 194,583 $ 51,787 $ 32,953 $ 239,696 $ 1,259,261 $ 84 $ 2,497,008 Construction Pass $ 243,483 $ 517,206 $ 305,966 $ 58,463 $ 374 $ 16,314 $ 67,769 $ — $ 1,209,575 Special Mention — 2,185 — — — — — — 2,185 Substandard — — 343 — — — — — 343 Total $ 243,483 $ 519,391 $ 306,309 $ 58,463 $ 374 $ 16,314 $ 67,769 $ — $ 1,212,103 Land - acquisition & development Pass $ 44,638 $ 79,721 $ 29,947 $ 10,865 $ 11,835 $ 29,115 $ 2,600 $ — $ 208,721 Substandard — — — — — 2,340 — — 2,340 Total $ 44,638 $ 79,721 $ 29,947 $ 10,865 $ 11,835 $ 31,455 $ 2,600 $ — $ 211,061 Total commercial loans Pass $ 1,293,479 $ 2,545,335 $ 1,341,765 $ 548,023 $ 500,357 $ 1,295,134 $ 1,258,117 $ 84 $ 8,782,294 Special Mention 3,454 2,185 4,494 31,333 32,952 10,388 35,150 — 119,956 Substandard — 13,447 30,497 42,236 6,072 50,297 61,658 — 204,207 Total $ 1,296,933 $ 2,560,967 $ 1,376,756 $ 621,592 $ 539,381 $ 1,355,819 $ 1,354,925 $ 84 $ 9,106,457 Term Loans Amortized Cost Basis by Origination Year YTD 2022 2021 2020 2019 2018 Prior to 2018 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 767,151 $ 1,479,568 $ 790,997 $ 349,688 $ 298,259 $ 1,711,718 $ — $ — $ 5,397,381 30 days past due — 219 — — — 3,066 — — 3,285 60 days past due — — 387 361 — 2,037 — — 2,785 90+ days past due — — — 342 169 14,683 — — 15,194 Total $ 767,151 $ 1,479,787 $ 791,384 $ 350,391 $ 298,428 $ 1,731,504 $ — $ — $ 5,418,645 Construction - custom Current $ 48,348 $ 255,534 $ 36,447 $ 2,184 $ 700 $ — $ — $ — $ 343,213 30 days past due — 435 — — — — — — 435 90+ days past due — — 465 — — — — — 465 Total $ 48,348 $ 255,969 $ 36,912 $ 2,184 $ 700 $ — $ — $ — $ 344,113 Land - consumer lot loans Current $ 34,562 $ 70,609 $ 21,962 $ 6,202 $ 3,727 $ 16,110 $ — $ — $ 153,172 30 days past due — — 51 — — 16 — — 67 60 days past due — — — — — 19 — — 19 90+ days past due — — 48 — — 243 — — 291 Total $ 34,562 $ 70,609 $ 22,061 $ 6,202 $ 3,727 $ 16,388 $ — $ — $ 153,549 HELOC Current $ — $ — $ — $ — $ — $ 5,154 $ 169,939 $ 164 $ 175,257 30 days past due — — — — — 150 89 108 347 60 days past due — — — — — 15 — — 15 90+ days past due — — — — — — 310 — 310 Total $ — $ — $ — $ — $ — $ 5,319 $ 170,338 $ 272 $ 175,929 Consumer Current $ 139 $ 10,325 $ 8,079 $ 366 $ 28,257 $ 8,495 $ 11,860 $ — $ 67,521 30 days past due — — — 6 — 47 1 — 54 60 days past due 2 — — — — 1 4 — 7 90+ days past due — — — 34 — 1 — — 35 Total $ 141 $ 10,325 $ 8,079 $ 406 $ 28,257 $ 8,544 $ 11,865 $ — $ 67,617 Total consumer loans Current $ 850,200 $ 1,816,036 $ 857,485 $ 358,440 $ 330,943 $ 1,741,477 $ 181,799 $ 164 $ 6,136,544 30 days past due — 654 51 6 — 3,279 90 108 4,188 60 days past due 2 — 387 361 — 2,072 4 — 2,826 90+ days past due — — 513 376 169 14,927 310 — 16,295 Total $ 850,202 $ 1,816,690 $ 858,436 $ 359,183 $ 331,112 $ 1,761,755 $ 182,203 $ 272 $ 6,159,853 The following tables provide the amortized cost of loans receivable based on risk rating categories as previously defined. March 31, 2022 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,373,674 $ 1,745 $ 2,238 $ — $ — $ 2,377,657 Commercial real estate 2,643,011 68,888 96,729 — — 2,808,628 Commercial & industrial 2,347,313 47,138 102,557 — — 2,497,008 Construction 1,209,575 2,185 343 — — 1,212,103 Land - acquisition & development 208,721 — 2,340 — — 211,061 Total commercial loans 8,782,294 119,956 204,207 — — 9,106,457 Consumer loans Single-family residential 5,396,628 — 22,017 — — 5,418,645 Construction - custom 343,648 — 465 — — 344,113 Land - consumer lot loans 153,240 — 309 — — 153,549 HELOC 175,600 — 329 — — 175,929 Consumer 67,601 — 16 — — 67,617 Total consumer loans 6,136,717 — 23,136 — — 6,159,853 Total $ 14,919,011 $ 119,956 $ 227,343 $ — $ — $ 15,266,310 Total grade as a % of total loans 97.72 % 0.79 % 1.49 % — % — % September 30, 2021 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,252,395 $ 4,874 $ 16,420 $ — $ — $ 2,273,689 Commercial real estate 2,174,386 57,625 197,321 — — 2,429,332 Commercial & industrial 2,108,152 48,124 147,651 — — 2,303,927 Construction 1,115,791 931 505 — — 1,117,227 Land - acquisition & development 190,076 — 2,340 — — 192,416 Total commercial loans 7,840,800 111,554 364,237 — — 8,316,591 Consumer loans Single-family residential 4,915,106 — 21,958 — — 4,937,064 Construction - custom 347,752 — — — — 347,752 Land - consumer lot loans 148,010 — 524 — — 148,534 HELOC 166,652 — 288 — — 166,940 Consumer 87,962 — 27 — — 87,989 Total consumer loans 5,665,482 — 22,797 — — 5,688,279 Total loans $ 13,506,282 $ 111,554 $ 387,034 $ — $ — $ 14,004,870 Total grade as a % of total loans 96.44 % 0.80 % 2.76 % — % — % The following tables provide information on amortized cost of loans receivable based on borrower payment activity. March 31, 2022 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,377,657 100.0 % $ — — % Commercial real estate 2,802,216 99.8 6,412 0.2 Commercial & industrial 2,492,219 99.8 4,789 0.2 Construction 1,211,760 100.0 343 0.0 Land - acquisition & development 208,721 98.9 2,340 1.1 Total commercial loans 9,092,573 99.8 13,884 0.2 Consumer loans Single-family residential 5,400,033 99.7 18,612 0.3 Construction - custom 343,648 99.9 465 0.1 Land - consumer lot loans 153,239 99.8 310 0.2 HELOC 175,600 99.8 329 0.2 Consumer 67,578 99.9 39 0.1 Total consumer loans 6,140,098 99.7 19,755 0.3 Total loans $ 15,232,671 99.8 % $ 33,639 0.2 % September 30, 2021 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,273,214 100.0 % $ 475 — % Commercial real estate 2,421,294 99.7 8,038 0.3 Commercial & industrial 2,303,562 100.0 365 — Construction 1,116,722 100.0 505 — Land - acquisition & development 190,076 98.8 2,340 1.2 Total commercial loans 8,304,868 99.9 11,723 0.1 Consumer loans Single-family residential 4,917,744 99.6 19,320 0.4 Construction - custom 347,752 100.0 — — Land - consumer lot loans 148,175 99.8 359 0.2 HELOC 166,653 99.8 287 0.2 Consumer 87,929 99.9 60 0.1 Total consumer loans 5,668,253 99.6 20,026 0.4 Total loans $ 13,973,121 99.8 % $ 31,749 0.2 %

Allowance for Losses on Loans (

Allowance for Losses on Loans (Tables)	6 Months Ended
	Mar. 31, 2022
Receivables [Abstract]
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 March 31, 2022 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 15,993 $ — $ — $ (1,530) $ 14,463 Commercial real estate 25,722 — 753 (1,793) 24,682 Commercial & industrial 47,231 (873) 2 7,543 53,903 Construction 24,766 — 179 (2,238) 22,707 Land - acquisition & development 14,125 — 20 (460) 13,685 Total commercial loans 127,837 (873) 954 1,522 129,440 Consumer loans Single-family residential 30,106 — 147 (1,261) 28,992 Construction - custom 3,719 — — (590) 3,129 Land - consumer lot loans 4,984 — 40 81 5,105 HELOC 2,365 — 100 10 2,475 Consumer 2,400 (39) 144 (262) 2,243 Total consumer loans 43,574 (39) 431 (2,022) 41,944 Total loans $ 171,411 $ (912) $ 1,385 $ (500) $ 171,384 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $0. Three Months Ended March 31, 2021 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 14,363 $ — $ — $ 3,413 $ 17,776 Commercial real estate 23,496 — 1,457 1,869 26,822 Commercial & industrial 44,317 (18) 11 3,484 47,794 Construction 26,365 — — (3,816) 22,549 Land - acquisition & development 10,666 — 410 (573) 10,503 Total commercial loans 119,207 (18) 1,878 4,377 125,444 Consumer loans Single-family residential 38,613 (106) 497 (3,896) 35,108 Construction - custom 3,594 — — (346) 3,248 Land - consumer lot loans 2,958 — 7 327 3,292 HELOC 2,362 — — (136) 2,226 Consumer 3,455 (84) 290 (326) 3,335 Total consumer loans 50,982 (190) 794 (4,377) 47,209 Total loans $ 170,189 $ (208) $ 2,672 $ — $ 172,653 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $0. Six Months Ended March 31, 2022 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 16,949 $ — $ — $ (2,486) $ 14,463 Commercial real estate 23,437 (529) 797 977 24,682 Commercial & industrial 45,957 (916) 64 8,798 53,903 Construction 25,585 — 2,179 (5,057) 22,707 Land - acquisition & development 13,447 (2) 40 200 13,685 Total commercial loans 125,375 (1,447) 3,080 2,432 129,440 Consumer loans Single-family residential 30,978 — 552 (2,538) 28,992 Construction - custom 4,907 — — (1,778) 3,129 Land - consumer lot loans 4,939 (27) 45 148 5,105 HELOC 2,390 — 101 (16) 2,475 Consumer 2,711 (115) 395 (748) 2,243 Total consumer loans 45,925 (142) 1,093 (4,932) 41,944 Total loans $ 171,300 $ (1,589) $ 4,173 $ (2,500) $ 171,384 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $2.5 million. Six Months Ended March 31, 2021 Beginning Allowance Charge-offs Recoveries Provision & Transfers (1) Ending Allowance (In thousands) Commercial loans Multi-family $ 13,853 $ — $ — $ 3,923 $ 17,776 Commercial real estate 22,516 — 2,246 2,060 26,822 Commercial & industrial 38,665 (20) 61 9,088 47,794 Construction 24,156 — — (1,607) 22,549 Land - acquisition & development 10,733 — 445 (675) 10,503 Total commercial loans 109,923 (20) 2,752 12,789 125,444 Consumer loans Single-family residential 45,186 (106) 1,276 (11,248) 35,108 Construction - custom 3,555 — — (307) 3,248 Land - consumer lot loans 2,729 — 14 549 3,292 HELOC 2,571 — — (345) 2,226 Consumer 2,991 (234) 516 62 3,335 Total consumer loans 57,032 (340) 1,806 (11,289) 47,209 Total loans $ 166,955 $ (360) $ 4,558 $ 1,500 $ 172,653 (1) Provision & transfer amounts within the table do not include the provision for unfunded commitments of $1.5 million.
Summary 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 March 31, 2022. Term Loans Amortized Cost Basis by Origination Year YTD 2022 2021 2020 2019 2018 Prior to 2018 Revolving Loans Revolving to Term Loans Total Loans Commercial loans Multi-family Pass $ 401,130 $ 747,291 $ 423,091 $ 143,051 $ 197,750 $ 440,126 $ 21,235 $ — $ 2,373,674 Special Mention — — 1,745 — — — — — 1,745 Substandard — — — — 649 1,589 — — 2,238 Total $ 401,130 $ 747,291 $ 424,836 $ 143,051 $ 198,399 $ 441,715 $ 21,235 $ — $ 2,377,657 Commercial real estate Pass $ 438,223 $ 665,379 $ 412,828 $ 289,728 $ 261,937 $ 571,942 $ 2,974 $ — $ 2,643,011 Special Mention — — — 25,548 32,952 10,388 — — 68,888 Substandard — — 8,253 42,150 931 44,309 1,086 — 96,729 Total $ 438,223 $ 665,379 $ 421,081 $ 357,426 $ 295,820 $ 626,639 $ 4,060 $ — $ 2,808,628 Commercial & industrial Pass $ 166,005 $ 535,738 $ 169,933 $ 45,916 $ 28,461 $ 237,637 $ 1,163,539 $ 84 $ 2,347,313 Special Mention 3,454 — 2,749 5,785 — — 35,150 — 47,138 Substandard — 13,447 21,901 86 4,492 2,059 60,572 — 102,557 Total $ 169,459 $ 549,185 $ 194,583 $ 51,787 $ 32,953 $ 239,696 $ 1,259,261 $ 84 $ 2,497,008 Construction Pass $ 243,483 $ 517,206 $ 305,966 $ 58,463 $ 374 $ 16,314 $ 67,769 $ — $ 1,209,575 Special Mention — 2,185 — — — — — — 2,185 Substandard — — 343 — — — — — 343 Total $ 243,483 $ 519,391 $ 306,309 $ 58,463 $ 374 $ 16,314 $ 67,769 $ — $ 1,212,103 Land - acquisition & development Pass $ 44,638 $ 79,721 $ 29,947 $ 10,865 $ 11,835 $ 29,115 $ 2,600 $ — $ 208,721 Substandard — — — — — 2,340 — — 2,340 Total $ 44,638 $ 79,721 $ 29,947 $ 10,865 $ 11,835 $ 31,455 $ 2,600 $ — $ 211,061 Total commercial loans Pass $ 1,293,479 $ 2,545,335 $ 1,341,765 $ 548,023 $ 500,357 $ 1,295,134 $ 1,258,117 $ 84 $ 8,782,294 Special Mention 3,454 2,185 4,494 31,333 32,952 10,388 35,150 — 119,956 Substandard — 13,447 30,497 42,236 6,072 50,297 61,658 — 204,207 Total $ 1,296,933 $ 2,560,967 $ 1,376,756 $ 621,592 $ 539,381 $ 1,355,819 $ 1,354,925 $ 84 $ 9,106,457 Term Loans Amortized Cost Basis by Origination Year YTD 2022 2021 2020 2019 2018 Prior to 2018 Revolving Loans Revolving to Term Loans Total Loans Consumer loans Single-family residential Current $ 767,151 $ 1,479,568 $ 790,997 $ 349,688 $ 298,259 $ 1,711,718 $ — $ — $ 5,397,381 30 days past due — 219 — — — 3,066 — — 3,285 60 days past due — — 387 361 — 2,037 — — 2,785 90+ days past due — — — 342 169 14,683 — — 15,194 Total $ 767,151 $ 1,479,787 $ 791,384 $ 350,391 $ 298,428 $ 1,731,504 $ — $ — $ 5,418,645 Construction - custom Current $ 48,348 $ 255,534 $ 36,447 $ 2,184 $ 700 $ — $ — $ — $ 343,213 30 days past due — 435 — — — — — — 435 90+ days past due — — 465 — — — — — 465 Total $ 48,348 $ 255,969 $ 36,912 $ 2,184 $ 700 $ — $ — $ — $ 344,113 Land - consumer lot loans Current $ 34,562 $ 70,609 $ 21,962 $ 6,202 $ 3,727 $ 16,110 $ — $ — $ 153,172 30 days past due — — 51 — — 16 — — 67 60 days past due — — — — — 19 — — 19 90+ days past due — — 48 — — 243 — — 291 Total $ 34,562 $ 70,609 $ 22,061 $ 6,202 $ 3,727 $ 16,388 $ — $ — $ 153,549 HELOC Current $ — $ — $ — $ — $ — $ 5,154 $ 169,939 $ 164 $ 175,257 30 days past due — — — — — 150 89 108 347 60 days past due — — — — — 15 — — 15 90+ days past due — — — — — — 310 — 310 Total $ — $ — $ — $ — $ — $ 5,319 $ 170,338 $ 272 $ 175,929 Consumer Current $ 139 $ 10,325 $ 8,079 $ 366 $ 28,257 $ 8,495 $ 11,860 $ — $ 67,521 30 days past due — — — 6 — 47 1 — 54 60 days past due 2 — — — — 1 4 — 7 90+ days past due — — — 34 — 1 — — 35 Total $ 141 $ 10,325 $ 8,079 $ 406 $ 28,257 $ 8,544 $ 11,865 $ — $ 67,617 Total consumer loans Current $ 850,200 $ 1,816,036 $ 857,485 $ 358,440 $ 330,943 $ 1,741,477 $ 181,799 $ 164 $ 6,136,544 30 days past due — 654 51 6 — 3,279 90 108 4,188 60 days past due 2 — 387 361 — 2,072 4 — 2,826 90+ days past due — — 513 376 169 14,927 310 — 16,295 Total $ 850,202 $ 1,816,690 $ 858,436 $ 359,183 $ 331,112 $ 1,761,755 $ 182,203 $ 272 $ 6,159,853 The following tables provide the amortized cost of loans receivable based on risk rating categories as previously defined. March 31, 2022 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,373,674 $ 1,745 $ 2,238 $ — $ — $ 2,377,657 Commercial real estate 2,643,011 68,888 96,729 — — 2,808,628 Commercial & industrial 2,347,313 47,138 102,557 — — 2,497,008 Construction 1,209,575 2,185 343 — — 1,212,103 Land - acquisition & development 208,721 — 2,340 — — 211,061 Total commercial loans 8,782,294 119,956 204,207 — — 9,106,457 Consumer loans Single-family residential 5,396,628 — 22,017 — — 5,418,645 Construction - custom 343,648 — 465 — — 344,113 Land - consumer lot loans 153,240 — 309 — — 153,549 HELOC 175,600 — 329 — — 175,929 Consumer 67,601 — 16 — — 67,617 Total consumer loans 6,136,717 — 23,136 — — 6,159,853 Total $ 14,919,011 $ 119,956 $ 227,343 $ — $ — $ 15,266,310 Total grade as a % of total loans 97.72 % 0.79 % 1.49 % — % — % September 30, 2021 Internally Assigned Grade Pass Special mention Substandard Doubtful Loss Total (In thousands, except ratio data) Loan type Commercial loans Multi-family $ 2,252,395 $ 4,874 $ 16,420 $ — $ — $ 2,273,689 Commercial real estate 2,174,386 57,625 197,321 — — 2,429,332 Commercial & industrial 2,108,152 48,124 147,651 — — 2,303,927 Construction 1,115,791 931 505 — — 1,117,227 Land - acquisition & development 190,076 — 2,340 — — 192,416 Total commercial loans 7,840,800 111,554 364,237 — — 8,316,591 Consumer loans Single-family residential 4,915,106 — 21,958 — — 4,937,064 Construction - custom 347,752 — — — — 347,752 Land - consumer lot loans 148,010 — 524 — — 148,534 HELOC 166,652 — 288 — — 166,940 Consumer 87,962 — 27 — — 87,989 Total consumer loans 5,665,482 — 22,797 — — 5,688,279 Total loans $ 13,506,282 $ 111,554 $ 387,034 $ — $ — $ 14,004,870 Total grade as a % of total loans 96.44 % 0.80 % 2.76 % — % — % The following tables provide information on amortized cost of loans receivable based on borrower payment activity. March 31, 2022 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,377,657 100.0 % $ — — % Commercial real estate 2,802,216 99.8 6,412 0.2 Commercial & industrial 2,492,219 99.8 4,789 0.2 Construction 1,211,760 100.0 343 0.0 Land - acquisition & development 208,721 98.9 2,340 1.1 Total commercial loans 9,092,573 99.8 13,884 0.2 Consumer loans Single-family residential 5,400,033 99.7 18,612 0.3 Construction - custom 343,648 99.9 465 0.1 Land - consumer lot loans 153,239 99.8 310 0.2 HELOC 175,600 99.8 329 0.2 Consumer 67,578 99.9 39 0.1 Total consumer loans 6,140,098 99.7 19,755 0.3 Total loans $ 15,232,671 99.8 % $ 33,639 0.2 % September 30, 2021 Performing Loans Non-Performing Loans Amount % of Total Amount % of Total (In thousands, except ratio data) Commercial loans Multi-family $ 2,273,214 100.0 % $ 475 — % Commercial real estate 2,421,294 99.7 8,038 0.3 Commercial & industrial 2,303,562 100.0 365 — Construction 1,116,722 100.0 505 — Land - acquisition & development 190,076 98.8 2,340 1.2 Total commercial loans 8,304,868 99.9 11,723 0.1 Consumer loans Single-family residential 4,917,744 99.6 19,320 0.4 Construction - custom 347,752 100.0 — — Land - consumer lot loans 148,175 99.8 359 0.2 HELOC 166,653 99.8 287 0.2 Consumer 87,929 99.9 60 0.1 Total consumer loans 5,668,253 99.6 20,026 0.4 Total loans $ 13,973,121 99.8 % $ 31,749 0.2 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
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. March 31, 2022 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 49,809 $ — $ 49,809 Asset-backed securities — 889,426 — 889,426 Municipal bonds — 38,468 — 38,468 Corporate debt securities — 333,999 — 333,999 Mortgage-backed securities Agency pass-through certificates — 597,903 — 597,903 Total available-for-sale securities — 1,909,605 — 1,909,605 Client swap program hedges — 27,353 — 27,353 Mortgage loan fair value hedges — 19,281 — 19,281 Borrowings cash flow hedges — 105,211 — 105,211 Total financial assets $ — $ 2,061,450 $ — $ 2,061,450 Financial Liabilities Client swap program hedges $ — $ 27,353 $ — $ 27,353 Commercial loan fair value hedges — 38 — 38 Total financial liabilities $ — $ 27,391 $ — $ 27,391 September 30, 2021 Level 1 Level 2 Level 3 Total (In thousands) Financial Assets Available-for-sale securities: U.S. government and agency securities $ — $ 61,779 $ — $ 61,779 Asset-backed securities — 1,078,681 1,078,681 Municipal bonds — 39,984 — 39,984 Corporate debt securities — 350,988 — 350,988 Mortgage-backed securities Agency pass-through certificates — 606,827 — 606,827 Total available-for-sale securities — 2,138,259 — 2,138,259 Client swap program hedges — 10,983 — 10,983 Borrowings cash flow hedges — 42,442 — 42,442 Total financial assets $ — $ 2,191,684 $ — $ 2,191,684 Financial Liabilities Client swap program hedges $ — $ 10,983 $ — $ 10,983 Commercial loan fair value hedges — 2,177 — 2,177 Mortgage loan fair value hedges 1,641 1,641 Total financial liabilities $ — $ 14,801 $ — $ 14,801
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 March 31, 2022 and March 31, 2021, 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. March 31, 2022 Three Months Ended March 31, 2022 Six Months Ended March 31, 2022 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ 3,816 $ 3,816 $ (896) $ (985) Real estate owned (2) — — 1,571 1,571 32 (472) Balance at end of period $ — $ — $ 5,387 $ 5,387 $ (864) $ (1,457) (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. March 31, 2021 Three Months Ended March 31, 2021 Six Months Ended March 31, 2021 Level 1 Level 2 Level 3 Total Total Gains (Losses) (In thousands) (In thousands) Loans (1) $ — $ — $ — $ — $ (25) $ (69) Real estate owned (2) — — 722 722 148 101 Balance at end of period $ — $ — $ 722 $ 722 $ 123 $ 32 (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.
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. March 31, 2022 September 30, 2021 Level in Fair Value Hierarchy Carrying Estimated Carrying Estimated ($ in thousands) Financial assets Cash and cash equivalents 1 $ 1,947,504 $ 1,947,504 $ 2,090,809 $ 2,090,809 Available-for-sale securities U.S. government and agency securities 2 49,809 49,809 61,779 61,779 Asset-backed securities 2 889,426 889,426 1,078,681 1,078,681 Municipal bonds 2 38,468 38,468 39,984 39,984 Corporate debt securities 2 333,999 333,999 350,988 350,988 Mortgage-backed securities Agency pass-through certificates 2 597,903 597,903 606,827 606,827 Total available-for-sale securities 1,909,605 1,909,605 2,138,259 2,138,259 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 2 301,221 294,354 366,025 379,547 Total held-to-maturity securities 301,221 294,354 366,025 379,547 Loans receivable 3 15,094,926 15,189,282 13,833,570 14,279,725 FHLB and FRB stock 2 78,873 78,873 102,863 102,863 Other assets - client swap program hedges 2 27,353 27,353 10,983 10,983 Other assets - mortgage loan fair value hedges 2 19,281 19,281 — — Other assets - borrowings cash flow hedges 2 105,211 105,211 42,442 42,442 Financial liabilities Time deposits 2 3,251,042 3,199,750 3,434,087 3,382,206 FHLB advances 2 1,720,000 1,601,795 1,720,000 1,692,412 Other liabilities - client swap program hedges 2 27,353 27,353 10,983 10,983 Other liabilities - commercial loan fair value hedges 2 38 38 2,177 2,177 Other liabilities - mortgage loan fair value hedges 2 — — 1,641 1,641
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. March 31, 2022 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due 1 to 5 years $ 50,441 $ 27 $ (659) $ 49,809 1.07 % Asset-backed securities 1 to 5 years 18,908 — (602) 18,306 1.08 5 to 10 years 62,883 121 (202) 62,802 0.79 Over 10 years 807,611 2,144 (1,437) 808,318 1.28 Corporate debt securities due 1 to 5 years 226,170 2,301 — 228,471 1.79 5 to 10 years 115,010 — (9,482) 105,528 3.87 Municipal bonds due Within 1 year 1,509 3 — 1,512 — 5 to 10 years 5,766 — (156) 5,610 0.16 Over 10 years 29,890 1,456 — 31,346 5.85 Mortgage-backed securities Agency pass-through certificates 603,800 4,936 (10,833) 597,903 2.60 1,921,988 10,988 (23,371) 1,909,605 1.95 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 301,221 170 (7,037) 294,354 3.16 301,221 170 (7,037) 294,354 3.16 $ 2,223,209 $ 11,158 $ (30,408) $ 2,203,959 2.11 % September 30, 2021 Amortized Gross Unrealized Fair Yield Gains Losses ($ in thousands) Available-for-sale securities U.S. government and agency securities due 1 to 5 years $ 47,339 $ 240 $ — $ 47,579 0.44 % 5 to 10 years 14,064 136 — 14,200 2.05 Asset-backed securities 1 to 5 years 19,730 — (434) 19,296 0.52 5 to 10 years 71,207 412 (97) 71,522 0.57 Over 10 years 973,892 14,069 (98) 987,863 0.94 Corporate debt securities due Within 1 year 225,928 7,860 — 233,788 1.57 1 to 5 years 86,802 1,345 — 88,147 4.64 5 to 10 years 28,804 249 — 29,053 1.95 Municipal bonds due Within 1 year 1,493 17 — 1,510 — 5 to 10 years 5,781 294 — 6,075 0.22 Over 10 years 29,909 2,490 — 32,399 5.85 Mortgage-backed securities Agency pass-through certificates 585,121 23,717 (2,011) 606,827 2.60 2,090,070 50,829 (2,640) 2,138,259 1.69 Held-to-maturity securities Mortgage-backed securities Agency pass-through certificates 366,025 13,522 — 379,547 3.17 366,025 13,522 — 379,547 3.17 $ 2,456,095 $ 64,351 $ (2,640) $ 2,517,806 1.89 %
Schedule of Unrealized Losses and Fair Value of Securities	The following tables show the gross unrealized losses and fair value of securities as of March 31, 2022 and September 30, 2021, by length of time that individual securities in each category have been in a continuous loss position. There were 131 and 31 securities with an unrealized loss as of March 31, 2022 and September 30, 2021, respectively. The decline in fair value since purchase is attributable to changes in interest rates. Because the Company does not intend to sell these securities and does not consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company does not consider these investments to have any credit impairment. March 31, 2022 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Corporate debt securities $ — $ — $ (9,482) $ 105,528 $ (9,482) $ 105,528 Municipal bonds (156) 5,610 — — (156) 5,610 U.S. government and agency securities (659) 34,697 — — (659) 34,697 Asset-backed securities (1,269) 277,125 (972) 67,792 (2,241) 344,917 Mortgage-backed securities (5,583) 234,166 (5,250) 63,445 (10,833) 297,611 (7,667) 551,598 (15,704) 236,765 (23,371) 788,363 Held-to-maturity securities Mortgage-backed securities (7,037) 291,911 — — (7,037) 291,911 $ (14,704) $ 843,509 $ (15,704) $ 236,765 $ (30,408) $ 1,080,274 September 30, 2021 Less than 12 months 12 months or more Total Unrealized Fair Unrealized Fair Unrealized Fair (In thousands) Available-for-sale securities Asset-backed securities $ (15) $ 4,639 $ (614) $ 70,058 $ (629) $ 74,697 Mortgage-backed securities (1,569) 47,758 (442) 32,266 (2,011) 80,024 (1,584) 52,397 (1,056) 102,324 (2,640) 154,721 Held-to-maturity securities Mortgage-backed securities — — — — — — $ (1,584) $ 52,397 $ (1,056) $ 102,324 $ (2,640) $ 154,721

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	6 Months Ended
	Mar. 31, 2022
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 March 31, 2022 and September 30, 2021. March 31, 2022 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 $ 615,830 $ 27,353 Other liabilities $ 615,830 $ 27,353 Commercial loan fair value hedges Other assets — — Other liabilities 42,209 38 Mortgage loan fair value hedges Other assets 470,000 19,281 Other liabilities — — Borrowings cash flow hedges Other assets 1,000,000 105,211 Other liabilities — — $ 2,085,830 $ 151,845 $ 658,039 $ 27,391 September 30, 2021 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 $ 644,355 $ 10,983 Other liabilities $ 644,355 $ 10,983 Commercial loan fair value hedges Other assets — — Other liabilities 44,678 2,177 Mortgage loan fair value hedges Other assets — — Other liabilities 470,000 1,641 Borrowings cash flow hedges Other assets 1,000,000 42,442 Other liabilities — — $ 1,644,355 $ 53,425 $ 1,159,033 $ 14,801
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 March 31, 2022 and September 30, 2021. (In thousands) March 31, 2022 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) $ 1,272,018 $ (18,845) $ 1,272,018 $ (18,845) (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 March 31, 2022, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $1,230 million, the cumulative basis adjustment associated with the hedging relationships was $(19) million, and the amount of the designated hedged items was $470 million. During the year ended September 30, 2021, hedge accounting was discontinued on $30 million (30%) of a $100 million last of layer hedge. At March 31, 2022, there is $1.0 million of remaining unamortized basis adjustment associated with the terminated portion of the hedge and it will be recognized over the remaining life of the associated pool of loans. (2) Includes the amortized cost basis of commercial loans designated in fair value hedging relationships. At March 31, 2022, the amortized cost basis of the hedged commercial loans was $42 million and the cumulative basis adjustment associated with the hedging relationships was $0.1 million. (In thousands) September 30, 2021 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) $ 1,515,487 $ 4,215 $ 1,515,487 $ 4,215 (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, 2021, the amortized cost basis of the closed loan portfolios used in the hedging relationships was $1,469 million, the cumulative basis adjustment associated with the hedging relationships was $1.9 million million, and the amount of the designated hedged items was $470 million. During the year ended September 30, 2021, hedge accounting was discontinued on $30 million (30%) of a $100 million last of layer hedge. (2) Includes the amortized cost basis of commercial loans designated in fair value hedging relationships. At September 30, 2021, the amortized cost basis of the hedged commercial loans was $47 million and the cumulative basis adjustment associated with the hedging relationships was $2.4 million. During the year ended September 30, 2021, hedge accounting was discontinued on a $46 million commercial loan hedge.
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 March 31, 2022 Three Months Ended March 31, 2021 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 $ 139,260 $ (7,525) $ 132,757 $ (11,991) Gain/(loss) on fair value hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ (1,199) $ (1,563) Recognized on derivatives 18,561 17,491 Recognized on hedged items (18,586) (17,377) Net income/(expense) recognized on fair value hedges $ (1,224) $ (1,449) Gain/(loss) on cash flow hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 1,715 $ 3,066 Amount of derivative gain/(loss) reclassified from AOCI into interest income/expense — 14,110 Net income/(expense) recognized on cash flow hedges $ 1,715 $ 17,176 Six Months Ended March 31, 2022 Six Months Ended March 31, 2021 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 $ 277,769 $ (15,368) $ 266,428 $ (25,189) Gain/(loss) on fair value hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ (2,570) $ (3,104) Recognized on derivatives 23,061 22,078 Recognized on hedged items (23,061) (21,833) Net income/(expense) recognized on fair value hedges $ (2,570) $ (2,859) Gain/(loss) on cash flow hedging relationships: Interest rate contracts Amounts related to interest settlements on derivatives $ 3,736 $ 6,664 Amount of derivative gain/(loss) reclassified from AOCI into interest income/expense — 14,110 Net income/(expense) recognized on cash flow hedges $ 3,736 $ 20,774
Schedule of Impact of Derivative Instruments	The following tables present the gain (loss) recognized in AOCI on derivative instruments related to cash flow hedges on borrowings for the periods presented, as well as the effect of reclassification adjustments. (In thousands) Three Months Ended March 31, Amounts recognized in AOCI 2022 2021 Interest rate contracts: Pay fixed/receive floating swaps on borrowings cash flow hedges $ 56,323 $ 70,565 Reclassification adjustment of net (gain)/loss included in net income — (14,110) Total pre-tax gain/(loss) recognized in AOCI $ 56,323 $ 56,455 (In thousands) Six Months Ended March 31, Amounts recognized in AOCI 2022 2021 Interest rate contracts: Pay fixed/receive floating swaps on borrowings cash flow hedges $ 62,769 $ 90,683 Reclassification adjustment of net (gain)/loss included in net income — (14,110) Total pre-tax gain/(loss) recognized in AOCI $ 62,769 $ 76,573 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 March 31, Derivative instruments Classification of gain/(loss) recognized in income on derivative instrument 2022 2021 Interest rate contracts: Pay fixed/receive floating swap Other noninterest income $ 33,298 $ 40,929 Receive fixed/pay floating swap Other noninterest income (33,298) (40,929) $ — $ —

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands	Feb. 08, 2021USD ($)$ / sharesshares	Mar. 31, 2022USD ($)branch	Mar. 31, 2021USD ($)	Sep. 30, 2021USD ($)
Accounting Policies [Line Items]
Number of bank branches | branch		214
Dividend rate	4.875%
Proceeds from issuance of preferred stock, net		$ 0	$ 293,325
Cash collateral		153,000		$ 1,500
Loans in process		2,440,430		2,232,836
Public Offering
Accounting Policies [Line Items]
Number of depositary shares | shares	12,000,000
Proceeds from issuance of preferred stock, net	$ 293,325
Public offering price (in usd per share) | $ / shares	$ 25
Percentage of preferred stock	2.50%
Public Offering | Series A Preferred Stock
Accounting Policies [Line Items]
Number of depositary shares | shares	300,000
Financing Receivable
Accounting Policies [Line Items]
Loans in process		$ 4,295,025		$ 3,804,444

Dividends and Share Repurchas_2

Dividends and Share Repurchases (Details) - $ / shares	Oct. 15, 2022	Jul. 15, 2022	Apr. 15, 2022	Feb. 18, 2022	Jan. 15, 2022	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Subsequent Event [Line Items]
Cash dividends per share (in dollars per share)				$ 0.24		$ 0.24	$ 0.23	$ 0.47	$ 0.45
Stock repurchased (in shares)						4,684
Average cost per share (in dollars per share)						$ 34.65
Remaining shares authorized to be repurchased (in shares)						3,728,320		3,728,320
Preferred stock dividends declared (in dollars per share)					$ 12.1875
Depository dividends declared (in dollars per share)					$ 0.30468750
Forecast
Subsequent Event [Line Items]
Preferred stock dividends declared (in dollars per share)	$ 12.1875	$ 12.1875	$ 12.1875
Depository dividends declared (in dollars per share)	$ 0.30468750	$ 0.30468750	$ 0.30468750

Loans Receivable - Schedule of

Loans Receivable - Schedule of Loans Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 17,775,453	$ 16,299,332
Ratio of loan type to all loans	100.00%	100.00%
Allowance for credit losses on loans	$ 171,384	$ 171,300
Loans in process	2,440,430	2,232,836
Net deferred fees, costs and discounts	68,713	61,626
Total loan contra accounts	2,680,527	2,465,762
Net loans	15,094,926	13,833,570
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 11,099,750	$ 10,160,647
Ratio of loan type to all loans	62.40%	62.30%
Commercial loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 2,392,810	$ 2,291,477
Ratio of loan type to all loans	13.50%	14.00%
Commercial loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 2,829,946	$ 2,443,845
Ratio of loan type to all loans	15.90%	15.00%
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 2,504,442	$ 2,314,654
Ratio of loan type to all loans	14.10%	14.20%
Commercial loans | Commercial & industrial | SBA Payroll Protection Program, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 111,000	$ 312,000
Commercial loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 3,136,239	$ 2,888,214
Ratio of loan type to all loans	17.60%	17.70%
Commercial loans | Land - acquisition & development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 236,313	$ 222,457
Ratio of loan type to all loans	1.30%	1.40%
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 6,675,703	$ 6,138,685
Ratio of loan type to all loans	37.60%	37.70%
Consumer loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 836,314	$ 783,221
Ratio of loan type to all loans	4.70%	4.80%
Consumer loans | Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 5,442,535	$ 4,951,627
Ratio of loan type to all loans	30.60%	30.40%
Consumer loans | Land - consumer lot loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 154,976	$ 149,956
Ratio of loan type to all loans	0.90%	0.90%
Consumer loans | HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 174,367	$ 165,989
Ratio of loan type to all loans	1.00%	1.00%
Consumer loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 67,511	$ 87,892
Ratio of loan type to all loans	0.40%	0.50%

Loans Receivable - Additional I

Loans Receivable - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivables for loans	$ 47,216	$ 46,234
Loans pledged to secure borrowings from the Federal Home Loan Bank	7,325,383	$ 5,930,015
Nonaccrual interest income recognized	1,733
Impaired, interest income on accrual accrual and performed loans	$ 631
Basis point reduction, minimum	1.00%
Basis point reduction, maximum	2.00%
Percent of TDRs classified as performing	97.30%
Single family residential loans as percentage of restructured loans	92.10%
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term for payment and rate reduction	6 months
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term for payment and rate reduction	24 months
Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring, amount	$ 57,255

Loans Receivable - Non-accrual

Loans Receivable - Non-accrual Loans and Loans 90 Days or More Past Due and Accruing (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual percent of total loans	0.22%	0.23%
Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 33,639	$ 31,749
Non-accrual loans with no related ACL	1,215	30
90 days or more past due and accruing	9,996	0
Financial Asset Originated | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	13,884	11,723
Non-accrual loans with no related ACL	1,215	30
90 days or more past due and accruing	9,996	0
Financial Asset Originated | Commercial loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	0	475
Non-accrual loans with no related 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	6,412	8,038
Non-accrual loans with no related 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	4,789	365
Non-accrual loans with no related ACL	1,215	30
90 days or more past due and accruing	9,996	0
Financial Asset Originated | Commercial loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	343	505
Non-accrual loans with no related 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	2,340	2,340
Non-accrual loans with no related 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	19,755	20,026
Non-accrual loans with no related 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	465	0
Non-accrual loans with no related 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	18,612	19,320
Non-accrual loans with no related 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	310	359
Non-accrual loans with no related 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	329	287
Non-accrual loans with no related 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	39	60
Non-accrual loans with no related 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	Mar. 31, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 15,266,310	$ 14,004,870
% based on $, past due	0.30%	0.19%
Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 15,220,904	$ 13,977,902
% based on $, current	99.70%	99.81%
Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 45,406	$ 26,968
% based on $, past due	0.30%	0.19%
30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 10,763	$ 4,802
% based on $, past due	0.07%	0.03%
60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,877	$ 2,595
% based on $, past due	0.02%	0.02%
90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 31,766	$ 19,571
% based on $, past due	0.21%	0.14%
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 9,106,457	$ 8,316,591
% based on $, past due	0.24%	0.05%
Commercial loans | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 9,084,360	$ 8,312,095
Commercial loans | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	22,097	4,496
Commercial loans | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	6,575	971
Commercial loans | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	51	64
Commercial loans | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	15,471	3,461
Commercial loans | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,377,657	$ 2,273,689
% based on $, past due	0.01%	0.02%
Commercial loans | Multi-family | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,377,347	$ 2,273,214
Commercial loans | Multi-family | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	310	475
Commercial loans | Multi-family | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	310	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	0	475
Commercial loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,808,628	$ 2,429,332
% based on $, past due	0.14%	0.05%
Commercial loans | Commercial real estate | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,804,726	$ 2,428,014
Commercial loans | Commercial real estate | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	3,902	1,318
Commercial loans | Commercial real estate | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,213	971
Commercial loans | Commercial real estate | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	64
Commercial loans | Commercial real estate | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,689	283
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,497,008	$ 2,303,927
% based on $, past due	0.62%	0.01%
Commercial loans | Commercial & industrial | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 2,481,463	$ 2,303,605
Commercial loans | Commercial & industrial | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	15,545	322
Commercial loans | Commercial & industrial | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	4,052	0
Commercial loans | Commercial & industrial | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	51	0
Commercial loans | Commercial & industrial | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	11,442	322
Commercial loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,212,103	$ 1,117,227
% based on $, past due	0.00%	0.00%
Commercial loans | Construction | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 1,212,103	$ 1,117,186
Commercial loans | Construction | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	41
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	41
Commercial loans | Land - acquisition & development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 211,061	$ 192,416
% based on $, past due	1.11%	1.22%
Commercial loans | Land - acquisition & development | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 208,721	$ 190,076
Commercial loans | Land - acquisition & development | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,340	2,340
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	2,340	2,340
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 6,159,853	$ 5,688,279
% based on $, past due	0.38%	0.40%
Consumer loans | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 6,136,544	$ 5,665,807
Consumer loans | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	23,309	22,472
Consumer loans | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	4,188	3,831
Consumer loans | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,826	2,531
Consumer loans | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	16,295	16,110
Consumer loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 344,113	$ 347,752
% based on $, past due	0.26%	0.00%
Consumer loans | Construction | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 343,213	$ 347,752
Consumer loans | Construction | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	900	0
Consumer loans | Construction | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	435	0
Consumer loans | Construction | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	0	0
Consumer loans | Construction | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	465	0
Consumer loans | Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 5,418,645	$ 4,937,064
% based on $, past due	0.39%	0.43%
Consumer loans | Single-family residential | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 5,397,381	$ 4,915,749
Consumer loans | Single-family residential | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	21,264	21,315
Consumer loans | Single-family residential | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	3,285	3,627
Consumer loans | Single-family residential | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,785	2,165
Consumer loans | Single-family residential | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	15,194	15,523
Consumer loans | Land - consumer lot loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 153,549	$ 148,534
% based on $, past due	0.25%	0.39%
Consumer loans | Land - consumer lot loans | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 153,172	$ 147,952
Consumer loans | Land - consumer lot loans | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	377	582
Consumer loans | Land - consumer lot loans | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	67	5
Consumer loans | Land - consumer lot loans | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	19	307
Consumer loans | Land - consumer lot loans | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	291	270
Consumer loans | HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 175,929	$ 166,940
% based on $, past due	0.38%	0.19%
Consumer loans | HELOC | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 175,257	$ 166,627
Consumer loans | HELOC | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	672	313
Consumer loans | HELOC | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	347	47
Consumer loans | HELOC | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	15	0
Consumer loans | HELOC | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	310	266
Consumer loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 67,617	$ 87,989
% based on $, past due	0.14%	0.30%
Consumer loans | Consumer | Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 67,521	$ 87,727
Consumer loans | Consumer | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	96	262
Consumer loans | Consumer | 30 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	54	152
Consumer loans | Consumer | 60 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	7	59
Consumer loans | Consumer | 90 Days Delinquent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 35	$ 51

Loans Receivable - Loans Based

Loans Receivable - Loans Based on Credit Quality Indicators (Details) $ in Thousands	Mar. 31, 2022USD ($)
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	$ 1,296,933
2021	2,560,967
2020	1,376,756
2019	621,592
2018	539,381
Prior to 2018	1,355,819
Revolving Loans	1,354,925
Revolving to Term Loans	84
Total Loans	9,106,457
Commercial loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	1,293,479
2021	2,545,335
2020	1,341,765
2019	548,023
2018	500,357
Prior to 2018	1,295,134
Revolving Loans	1,258,117
Revolving to Term Loans	84
Total Loans	8,782,294
Commercial loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	3,454
2021	2,185
2020	4,494
2019	31,333
2018	32,952
Prior to 2018	10,388
Revolving Loans	35,150
Revolving to Term Loans	0
Total Loans	119,956
Commercial loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	13,447
2020	30,497
2019	42,236
2018	6,072
Prior to 2018	50,297
Revolving Loans	61,658
Revolving to Term Loans	0
Total Loans	204,207
Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	401,130
2021	747,291
2020	424,836
2019	143,051
2018	198,399
Prior to 2018	441,715
Revolving Loans	21,235
Revolving to Term Loans	0
Total Loans	2,377,657
Commercial loans | Multi-family | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	401,130
2021	747,291
2020	423,091
2019	143,051
2018	197,750
Prior to 2018	440,126
Revolving Loans	21,235
Revolving to Term Loans	0
Total Loans	2,373,674
Commercial loans | Multi-family | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	1,745
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	1,745
Commercial loans | Multi-family | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	649
Prior to 2018	1,589
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,238
Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	438,223
2021	665,379
2020	421,081
2019	357,426
2018	295,820
Prior to 2018	626,639
Revolving Loans	4,060
Revolving to Term Loans	0
Total Loans	2,808,628
Commercial loans | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	438,223
2021	665,379
2020	412,828
2019	289,728
2018	261,937
Prior to 2018	571,942
Revolving Loans	2,974
Revolving to Term Loans	0
Total Loans	2,643,011
Commercial loans | Commercial real estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	25,548
2018	32,952
Prior to 2018	10,388
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	68,888
Commercial loans | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	8,253
2019	42,150
2018	931
Prior to 2018	44,309
Revolving Loans	1,086
Revolving to Term Loans	0
Total Loans	96,729
Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	169,459
2021	549,185
2020	194,583
2019	51,787
2018	32,953
Prior to 2018	239,696
Revolving Loans	1,259,261
Revolving to Term Loans	84
Total Loans	2,497,008
Commercial loans | Commercial & industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	166,005
2021	535,738
2020	169,933
2019	45,916
2018	28,461
Prior to 2018	237,637
Revolving Loans	1,163,539
Revolving to Term Loans	84
Total Loans	2,347,313
Commercial loans | Commercial & industrial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	3,454
2021	0
2020	2,749
2019	5,785
2018	0
Prior to 2018	0
Revolving Loans	35,150
Revolving to Term Loans	0
Total Loans	47,138
Commercial loans | Commercial & industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	13,447
2020	21,901
2019	86
2018	4,492
Prior to 2018	2,059
Revolving Loans	60,572
Revolving to Term Loans	0
Total Loans	102,557
Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	243,483
2021	519,391
2020	306,309
2019	58,463
2018	374
Prior to 2018	16,314
Revolving Loans	67,769
Revolving to Term Loans	0
Total Loans	1,212,103
Commercial loans | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	243,483
2021	517,206
2020	305,966
2019	58,463
2018	374
Prior to 2018	16,314
Revolving Loans	67,769
Revolving to Term Loans	0
Total Loans	1,209,575
Commercial loans | Construction | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	2,185
2020	0
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,185
Commercial loans | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	343
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	343
Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	44,638
2021	79,721
2020	29,947
2019	10,865
2018	11,835
Prior to 2018	31,455
Revolving Loans	2,600
Revolving to Term Loans	0
Total Loans	211,061
Commercial loans | Land - acquisition & development | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	44,638
2021	79,721
2020	29,947
2019	10,865
2018	11,835
Prior to 2018	29,115
Revolving Loans	2,600
Revolving to Term Loans	0
Total Loans	208,721
Commercial loans | Land - acquisition & development | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	2,340
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,340
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	850,202
2021	1,816,690
2020	858,436
2019	359,183
2018	331,112
Prior to 2018	1,761,755
Revolving Loans	182,203
Revolving to Term Loans	272
Total Loans	6,159,853
Consumer loans | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	850,200
2021	1,816,036
2020	857,485
2019	358,440
2018	330,943
Prior to 2018	1,741,477
Revolving Loans	181,799
Revolving to Term Loans	164
Total Loans	6,136,544
Consumer loans | 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	654
2020	51
2019	6
2018	0
Prior to 2018	3,279
Revolving Loans	90
Revolving to Term Loans	108
Total Loans	4,188
Consumer loans | 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	2
2021	0
2020	387
2019	361
2018	0
Prior to 2018	2,072
Revolving Loans	4
Revolving to Term Loans	0
Total Loans	2,826
Consumer loans | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	513
2019	376
2018	169
Prior to 2018	14,927
Revolving Loans	310
Revolving to Term Loans	0
Total Loans	16,295
Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	48,348
2021	255,969
2020	36,912
2019	2,184
2018	700
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	344,113
Consumer loans | Construction | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	48,348
2021	255,534
2020	36,447
2019	2,184
2018	700
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	343,213
Consumer loans | Construction | 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	435
2020	0
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	435
Consumer loans | Construction | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	465
2019	0
2018	0
Prior to 2018	0
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	465
Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	767,151
2021	1,479,787
2020	791,384
2019	350,391
2018	298,428
Prior to 2018	1,731,504
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	5,418,645
Consumer loans | Single-family residential | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	767,151
2021	1,479,568
2020	790,997
2019	349,688
2018	298,259
Prior to 2018	1,711,718
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	5,397,381
Consumer loans | Single-family residential | 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	219
2020	0
2019	0
2018	0
Prior to 2018	3,066
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	3,285
Consumer loans | Single-family residential | 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	387
2019	361
2018	0
Prior to 2018	2,037
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	2,785
Consumer loans | Single-family residential | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	342
2018	169
Prior to 2018	14,683
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	15,194
Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	34,562
2021	70,609
2020	22,061
2019	6,202
2018	3,727
Prior to 2018	16,388
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	153,549
Consumer loans | Land - consumer lot loans | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	34,562
2021	70,609
2020	21,962
2019	6,202
2018	3,727
Prior to 2018	16,110
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	153,172
Consumer loans | Land - consumer lot loans | 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	51
2019	0
2018	0
Prior to 2018	16
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	67
Consumer loans | Land - consumer lot loans | 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	19
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	19
Consumer loans | Land - consumer lot loans | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	48
2019	0
2018	0
Prior to 2018	243
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	291
Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	5,319
Revolving Loans	170,338
Revolving to Term Loans	272
Total Loans	175,929
Consumer loans | HELOC | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	5,154
Revolving Loans	169,939
Revolving to Term Loans	164
Total Loans	175,257
Consumer loans | HELOC | 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	150
Revolving Loans	89
Revolving to Term Loans	108
Total Loans	347
Consumer loans | HELOC | 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	15
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	15
Consumer loans | HELOC | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	0
2018	0
Prior to 2018	0
Revolving Loans	310
Revolving to Term Loans	0
Total Loans	310
Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	141
2021	10,325
2020	8,079
2019	406
2018	28,257
Prior to 2018	8,544
Revolving Loans	11,865
Revolving to Term Loans	0
Total Loans	67,617
Consumer loans | Consumer | Current
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	139
2021	10,325
2020	8,079
2019	366
2018	28,257
Prior to 2018	8,495
Revolving Loans	11,860
Revolving to Term Loans	0
Total Loans	67,521
Consumer loans | Consumer | 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	6
2018	0
Prior to 2018	47
Revolving Loans	1
Revolving to Term Loans	0
Total Loans	54
Consumer loans | Consumer | 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	2
2021	0
2020	0
2019	0
2018	0
Prior to 2018	1
Revolving Loans	4
Revolving to Term Loans	0
Total Loans	7
Consumer loans | Consumer | 90+ days past due
Financing Receivable, Credit Quality Indicator [Line Items]
YTD 2022	0
2021	0
2020	0
2019	34
2018	0
Prior to 2018	1
Revolving Loans	0
Revolving to Term Loans	0
Total Loans	$ 35

Allowance for Losses on Loans -

Allowance for Losses on Loans - Activity in Allowance for Loan Losses by Loan Portfolio Segment and Class (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	$ 171,411	$ 170,189	$ 171,300	$ 166,955
Charge-offs	(912)	(208)	(1,589)	(360)
Recoveries	1,385	2,672	4,173	4,558
Provision & Transfers	(500)	0	(2,500)	1,500
Ending Allowance	171,384	172,653	171,384	172,653
Unfunded commitments
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision & Transfers	0	0	2,500	1,500
Commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	127,837	119,207	125,375	109,923
Charge-offs	(873)	(18)	(1,447)	(20)
Recoveries	954	1,878	3,080	2,752
Provision & Transfers	1,522	4,377	2,432	12,789
Ending Allowance	129,440	125,444	129,440	125,444
Commercial loans | Multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	15,993	14,363	16,949	13,853
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision & Transfers	(1,530)	3,413	(2,486)	3,923
Ending Allowance	14,463	17,776	14,463	17,776
Commercial loans | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	25,722	23,496	23,437	22,516
Charge-offs	0	0	(529)	0
Recoveries	753	1,457	797	2,246
Provision & Transfers	(1,793)	1,869	977	2,060
Ending Allowance	24,682	26,822	24,682	26,822
Commercial loans | Commercial & industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	47,231	44,317	45,957	38,665
Charge-offs	(873)	(18)	(916)	(20)
Recoveries	2	11	64	61
Provision & Transfers	7,543	3,484	8,798	9,088
Ending Allowance	53,903	47,794	53,903	47,794
Commercial loans | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	24,766	26,365	25,585	24,156
Charge-offs	0	0	0	0
Recoveries	179	0	2,179	0
Provision & Transfers	(2,238)	(3,816)	(5,057)	(1,607)
Ending Allowance	22,707	22,549	22,707	22,549
Commercial loans | Land - acquisition & development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	14,125	10,666	13,447	10,733
Charge-offs	0	0	(2)	0
Recoveries	20	410	40	445
Provision & Transfers	(460)	(573)	200	(675)
Ending Allowance	13,685	10,503	13,685	10,503
Consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	43,574	50,982	45,925	57,032
Charge-offs	(39)	(190)	(142)	(340)
Recoveries	431	794	1,093	1,806
Provision & Transfers	(2,022)	(4,377)	(4,932)	(11,289)
Ending Allowance	41,944	47,209	41,944	47,209
Consumer loans | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	3,719	3,594	4,907	3,555
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision & Transfers	(590)	(346)	(1,778)	(307)
Ending Allowance	3,129	3,248	3,129	3,248
Consumer loans | Single-family residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	30,106	38,613	30,978	45,186
Charge-offs	0	(106)	0	(106)
Recoveries	147	497	552	1,276
Provision & Transfers	(1,261)	(3,896)	(2,538)	(11,248)
Ending Allowance	28,992	35,108	28,992	35,108
Consumer loans | Land - consumer lot loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	4,984	2,958	4,939	2,729
Charge-offs	0	0	(27)	0
Recoveries	40	7	45	14
Provision & Transfers	81	327	148	549
Ending Allowance	5,105	3,292	5,105	3,292
Consumer loans | HELOC
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	2,365	2,362	2,390	2,571
Charge-offs	0	0	0	0
Recoveries	100	0	101	0
Provision & Transfers	10	(136)	(16)	(345)
Ending Allowance	2,475	2,226	2,475	2,226
Consumer loans | Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Allowance	2,400	3,455	2,711	2,991
Charge-offs	(39)	(84)	(115)	(234)
Recoveries	144	290	395	516
Provision & Transfers	(262)	(326)	(748)	62
Ending Allowance	$ 2,243	$ 3,335	$ 2,243	$ 3,335

Allowance for Losses on Loans_2

Allowance for Losses on Loans - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (release) for credit losses	$ (500,000)	$ 0	$ 0	$ 3,000,000
Net (charge-offs) recoveries	473,000	2,464,000	2,584,000	4,198,000
Allowance for credit losses on loans	171,384,000	172,653,000	171,384,000	172,653,000	$ 171,411,000	$ 171,300,000	$ 170,189,000	$ 166,955,000
Gross loans	$ 15,266,310,000		$ 15,266,310,000			$ 14,004,870,000
% based on $, past due	0.30%		0.30%			0.19%
Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 33,639,000		$ 33,639,000			$ 31,749,000
Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 47,243,000		$ 47,243,000			$ 43,625,000
Ratio of non-performing assets to total assets	0.23%		0.23%			0.22%
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses on loans	$ 129,440,000	125,444,000	$ 129,440,000	125,444,000	127,837,000	$ 125,375,000	119,207,000	109,923,000
Gross loans	$ 9,106,457,000		$ 9,106,457,000			$ 8,316,591,000
% based on $, past due	0.24%		0.24%			0.05%
Commercial loans | Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 13,884,000		$ 13,884,000			$ 11,723,000
Commercial loans | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses on loans	53,903,000	$ 47,794,000	53,903,000	$ 47,794,000	$ 47,231,000	45,957,000	$ 44,317,000	$ 38,665,000
Gross loans	$ 2,497,008,000		$ 2,497,008,000			$ 2,303,927,000
% based on $, past due	0.62%		0.62%			0.01%
Commercial loans | Commercial & industrial | Financial Asset Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 4,789,000		$ 4,789,000			$ 365,000
Commercial loans | Commercial & industrial | SBA Payroll Protection Program, CARES Act
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses on loans	0		0			0
Loans receivable, net of allowance for loan losses	$ 109,746,000		$ 109,746,000			$ 305,162,000

Allowance for Losses on Loans_3

Allowance for Losses on Loans - Internally Assigned Grade (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2022	Sep. 30, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 15,266,310	$ 14,004,870
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 14,919,011	$ 13,506,282
Pass | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	97.72%	96.44%
Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 119,956	$ 111,554
Special mention | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	0.79%	0.80%
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 227,343	$ 387,034
Substandard | Accounts Receivable | Credit Concentration Risk
Financing Receivable, Credit Quality Indicator [Line Items]
Total grade as a % of total loans	1.49%	2.76%
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	0.00%	0.00%
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	0.00%	0.00%
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	$ 9,106,457	$ 8,316,591
Commercial loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	8,782,294	7,840,800
Commercial loans | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	119,956	111,554
Commercial loans | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	204,207	364,237
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	2,377,657	2,273,689
Commercial loans | Multi-family | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,373,674	2,252,395
Commercial loans | Multi-family | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	1,745	4,874
Commercial loans | Multi-family | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,238	16,420
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	2,808,628	2,429,332
Commercial loans | Commercial real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,643,011	2,174,386
Commercial loans | Commercial real estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	68,888	57,625
Commercial loans | Commercial real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	96,729	197,321
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	2,497,008	2,303,927
Commercial loans | Commercial & industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,347,313	2,108,152
Commercial loans | Commercial & industrial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	47,138	48,124
Commercial loans | Commercial & industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	102,557	147,651
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	1,212,103	1,117,227
Commercial loans | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	1,209,575	1,115,791
Commercial loans | Construction | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	2,185	931
Commercial loans | Construction | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	343	505
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	211,061	192,416
Commercial loans | Land - acquisition & development | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	208,721	190,076
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	2,340	2,340
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	6,159,853	5,688,279
Consumer loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	6,136,717	5,665,482
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	23,136	22,797
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	344,113	347,752
Consumer loans | Construction | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	343,648	347,752
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	465	0
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	5,418,645	4,937,064
Consumer loans | Single-family residential | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	5,396,628	4,915,106
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	22,017	21,958
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	153,549	148,534
Consumer loans | Land - consumer lot loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	153,240	148,010
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	309	524
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	175,929	166,940
Consumer loans | HELOC | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	175,600	166,652
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	329	288
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	67,617	87,989
Consumer loans | Consumer | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Gross loans	67,601	87,962
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	16	27
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_4

Allowance for Losses on Loans - Credit Risk Profile Based on Payment Activity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 15,266,310	$ 14,004,870
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	9,106,457	8,316,591
Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	2,377,657	2,273,689
Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	2,808,628	2,429,332
Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	2,497,008	2,303,927
Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	1,212,103	1,117,227
Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	211,061	192,416
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	6,159,853	5,688,279
Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	344,113	347,752
Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	5,418,645	4,937,064
Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	153,549	148,534
Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	175,929	166,940
Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	67,617	87,989
Performing Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 15,232,671	$ 13,973,121
% of Total Loans	99.80%	99.80%
Performing Loans | Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 9,092,573	$ 8,304,868
% of Total Loans	99.80%	99.90%
Performing Loans | Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 2,377,657	$ 2,273,214
% of Total Loans	100.00%	100.00%
Performing Loans | Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 2,802,216	$ 2,421,294
% of Total Loans	99.80%	99.70%
Performing Loans | Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 2,492,219	$ 2,303,562
% of Total Loans	99.80%	100.00%
Performing Loans | Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 1,211,760	$ 1,116,722
% of Total Loans	100.00%	100.00%
Performing Loans | Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 208,721	$ 190,076
% of Total Loans	98.90%	98.80%
Performing Loans | Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 6,140,098	$ 5,668,253
% of Total Loans	99.70%	99.60%
Performing Loans | Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 343,648	$ 347,752
% of Total Loans	99.90%	100.00%
Performing Loans | Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 5,400,033	$ 4,917,744
% of Total Loans	99.70%	99.60%
Performing Loans | Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 153,239	$ 148,175
% of Total Loans	99.80%	99.80%
Performing Loans | Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 175,600	$ 166,653
% of Total Loans	99.80%	99.80%
Performing Loans | Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 67,578	$ 87,929
% of Total Loans	99.90%	99.90%
Non-Performing Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 33,639	$ 31,749
% of Total Loans	0.20%	0.20%
Non-Performing Loans | Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 13,884	$ 11,723
% of Total Loans	0.20%	0.10%
Non-Performing Loans | Commercial loans | Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 0	$ 475
% of Total Loans	0.00%	0.00%
Non-Performing Loans | Commercial loans | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 6,412	$ 8,038
% of Total Loans	0.20%	0.30%
Non-Performing Loans | Commercial loans | Commercial & industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 4,789	$ 365
% of Total Loans	0.20%	0.00%
Non-Performing Loans | Commercial loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 343	$ 505
% of Total Loans	0.00%	0.00%
Non-Performing Loans | Commercial loans | Land - acquisition & development
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 2,340	$ 2,340
% of Total Loans	1.10%	1.20%
Non-Performing Loans | Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 19,755	$ 20,026
% of Total Loans	0.30%	0.40%
Non-Performing Loans | Consumer loans | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 465	$ 0
% of Total Loans	0.10%	0.00%
Non-Performing Loans | Consumer loans | Single-family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 18,612	$ 19,320
% of Total Loans	0.30%	0.40%
Non-Performing Loans | Consumer loans | Land - consumer lot loans
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 310	$ 359
% of Total Loans	0.20%	0.20%
Non-Performing Loans | Consumer loans | HELOC
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 329	$ 287
% of Total Loans	0.20%	0.20%
Non-Performing Loans | Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Amount	$ 39	$ 60
% of Total Loans	0.10%	0.10%

Fair Value Measurements - Recur

Fair Value Measurements - Recurring (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	$ 1,909,605	$ 2,138,259
Total financial assets	2,203,959	2,517,806
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	1,909,605	2,138,259
Total financial assets	2,061,450	2,191,684
Total financial liabilities	27,391	14,801
Recurring | Client swap program hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	27,353	10,983
Derivative liabilities	27,353	10,983
Recurring | Commercial loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	38	2,177
Recurring | Mortgage loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	19,281
Derivative liabilities		1,641
Recurring | Borrowings cash flow hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	105,211	42,442
Recurring | U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	49,809	61,779
Recurring | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	889,426	1,078,681
Recurring | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	38,468	39,984
Recurring | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	333,999	350,988
Recurring | Agency pass-through certificates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	597,903	606,827
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 liabilities	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
Derivative liabilities
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 1 | U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Recurring | Level 1 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Recurring | Level 1 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Recurring | Level 1 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Recurring | Level 1 | Agency pass-through certificates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	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	1,909,605	2,138,259
Total financial assets	2,061,450	2,191,684
Total financial liabilities	27,391	14,801
Recurring | Level 2 | Client swap program hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	27,353	10,983
Derivative liabilities	27,353	10,983
Recurring | Level 2 | Commercial loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	38	2,177
Recurring | Level 2 | Mortgage loan fair value hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	19,281
Derivative liabilities		1,641
Recurring | Level 2 | Borrowings cash flow hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	105,211	42,442
Recurring | Level 2 | U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	49,809	61,779
Recurring | Level 2 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	889,426	1,078,681
Recurring | Level 2 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	38,468	39,984
Recurring | Level 2 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	333,999	350,988
Recurring | Level 2 | Agency pass-through certificates
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	597,903	606,827
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 liabilities	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
Derivative liabilities
Recurring | Level 3 | Borrowings cash flow hedges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Level 3 | U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Recurring | Level 3 | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0
Recurring | Level 3 | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Recurring | Level 3 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, at fair value	0	0
Recurring | Level 3 | Agency pass-through certificates
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 - Nonre

Fair Value Measurements - Nonrecurring (Details) - Nonrecurring - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	$ 5,387	$ 722	$ 5,387	$ 722
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	0	0	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	0	0	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	5,387	722	5,387	722
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	3,816	0	3,816	0
Impaired loans | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	0	0	0	0
Impaired loans | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	0	0	0	0
Impaired loans | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	3,816	0	3,816	0
Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	1,571	722	1,571	722
Real estate owned | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	0	0	0	0
Real estate owned | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	0	0	0	0
Real estate owned | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and real estate owned, fair value	1,571	722	1,571	722
Changes measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) related to loans and real estate owned	(864)	123	(1,457)	32
Changes measurement | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) related to loans and real estate owned	(896)	(25)	(985)	(69)
Changes measurement | Real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) related to loans and real estate owned	$ 32	$ 148	$ (472)	$ 101

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value by Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	$ 1,909,605	$ 2,138,259
FHLB and FRB stock	78,873	102,863
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	1,909,605	2,138,259
Held-to-maturity securities	301,221	366,025
Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	1,909,605	2,138,259
Held-to-maturity securities	294,354	379,547
Level 1 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,947,504	2,090,809
Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,947,504	2,090,809
Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
FHLB and FRB stock	78,873	102,863
Time deposits	3,251,042	3,434,087
FHLB advances	1,720,000	1,720,000
Level 2 | Carrying Amount | Client swap program hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	27,353	10,983
Other liabilities	27,353	10,983
Level 2 | Carrying Amount | Commercial loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other liabilities	38	2,177
Level 2 | Carrying Amount | Mortgage loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	19,281	0
Other liabilities	0	1,641
Level 2 | Carrying Amount | Borrowings cash flow hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	105,211	42,442
Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
FHLB and FRB stock	78,873	102,863
Time deposits	3,199,750	3,382,206
FHLB advances	1,601,795	1,692,412
Level 2 | Estimated Fair Value | Client swap program hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	27,353	10,983
Other liabilities	27,353	10,983
Level 2 | Estimated Fair Value | Commercial loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other liabilities	38	2,177
Level 2 | Estimated Fair Value | Mortgage loan fair value hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	19,281	0
Other liabilities	0	1,641
Level 2 | Estimated Fair Value | Borrowings cash flow hedges
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	105,211	42,442
Level 3 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable	15,094,926	13,833,570
Level 3 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable	15,189,282	14,279,725
U.S. government and agency securities | Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	49,809	61,779
U.S. government and agency securities | Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	49,809	61,779
Asset-backed securities | Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	889,426	1,078,681
Asset-backed securities | Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	889,426	1,078,681
Municipal bonds | Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	38,468	39,984
Municipal bonds | Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	38,468	39,984
Corporate debt securities | Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	333,999	350,988
Corporate debt securities | Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	333,999	350,988
Agency pass-through certificates | Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	597,903	606,827
Held-to-maturity securities	301,221	366,025
Agency pass-through certificates | Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities, at fair value	597,903	606,827
Held-to-maturity securities	$ 294,354	$ 379,547

Fair Value Measurements - Inves

Fair Value Measurements - Investments by Contractual Maturity Date (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Amortized Cost, Available-for-sale securities
Amortized Cost	$ 1,921,988	$ 2,090,070
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains	10,988	50,829
Gross unrealized loss	(23,371)	(2,640)
Fair Value, Available-for-sale securities
Fair value	$ 1,909,605	$ 2,138,259
Yield, Available-for-sale securities
Yield	1.95%	1.69%
Amortized Cost, Held-to-maturity securities
Held-to-maturity securities, amortized cost	$ 301,221	$ 366,025
Gross Unrealized Gains / Losses, Held-to-maturity securities
Held-to-maturity securities, gross unrealized gains	170	13,522
Held-to-maturity securities, gross unrealized losses	(7,037)	0
Fair Value, Held-to-maturity securities
Held-to-maturity securities, fair value	$ 294,354	$ 379,547
Yield, Held-to-maturity securities
Held-to-maturity securities, yield	3.16%	3.17%
Investments	$ 2,223,209	$ 2,456,095
Gross unrealized gains on investments	11,158	64,351
Gross unrealized losses on investments	(30,408)	(2,640)
Total financial assets	$ 2,203,959	$ 2,517,806
Yield on investments	2.11%	1.89%
U.S. government and agency securities
Amortized Cost, Available-for-sale securities
Amortized cost, 1 to 5 years	$ 50,441	$ 47,339
Amortized cost, 5 to 10 years		14,064
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, 1 to 5 years	27	240
Gross unrealized gains, 5 to 10 years		136
Gross unrealized losses, 1 to 5 years	(659)	0
Gross unrealized losses, 5 to 10 years		0
Fair Value, Available-for-sale securities
Fair value, 1 to 5 years	$ 49,809	47,579
Fair value, 5 to 10 years		$ 14,200
Yield, Available-for-sale securities
Yield, 1 to 5 years	1.07%	0.44%
Yield, 5 to 10 years		2.05%
Asset-backed securities
Amortized Cost, Available-for-sale securities
Amortized cost, 1 to 5 years	$ 18,908	$ 19,730
Amortized cost, 5 to 10 years	62,883	71,207
Amortized cost, over 10 years	807,611	973,892
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, 1 to 5 years	0	0
Gross unrealized gains, 5 to 10 years	121	412
Gross unrealized gains, over 10 years	2,144	14,069
Gross unrealized losses, 1 to 5 years	(602)	(434)
Gross unrealized losses, 5 to 10 years	(202)	(97)
Gross unrealized losses, over 10 years	(1,437)	(98)
Fair Value, Available-for-sale securities
Fair value, 1 to 5 years	18,306	19,296
Fair value, 5 to 10 years	62,802	71,522
Fair value, over 10 years	$ 808,318	$ 987,863
Yield, Available-for-sale securities
Yield, 1 to 5 years	1.08%	0.52%
Yield, 5 to 10 years	0.79%	0.57%
Yield, over 10 years	1.28%	0.94%
Corporate debt securities
Amortized Cost, Available-for-sale securities
Amortized cost, within 1 year		$ 225,928
Amortized cost, 1 to 5 years	$ 226,170	86,802
Amortized cost, 5 to 10 years	115,010	28,804
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, within 1 year		7,860
Gross unrealized gains, 1 to 5 years	2,301	1,345
Gross unrealized gains, 5 to 10 years	0	249
Gross unrealized losses, Within 1 year		0
Gross unrealized losses, 1 to 5 years	0	0
Gross unrealized losses, 5 to 10 years	(9,482)	0
Fair Value, Available-for-sale securities
Fair value, within 1 year		233,788
Fair value, 1 to 5 years	228,471	88,147
Fair value, 5 to 10 years	$ 105,528	$ 29,053
Yield, Available-for-sale securities
Yield, within 1 year		1.57%
Yield, 1 to 5 years	1.79%	4.64%
Yield, 5 to 10 years	3.87%	1.95%
Municipal bonds due
Amortized Cost, Available-for-sale securities
Amortized cost, within 1 year	$ 1,509	$ 1,493
Amortized cost, 5 to 10 years	5,766	5,781
Amortized cost, over 10 years	29,890	29,909
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, within 1 year	3	17
Gross unrealized gains, 5 to 10 years	0	294
Gross unrealized gains, over 10 years	1,456	2,490
Gross unrealized losses, Within 1 year	0	0
Gross unrealized losses, 5 to 10 years	(156)	0
Gross unrealized losses, over 10 years	0	0
Fair Value, Available-for-sale securities
Fair value, within 1 year	1,512	1,510
Fair value, 5 to 10 years	5,610	6,075
Fair value, over 10 years	$ 31,346	$ 32,399
Yield, Available-for-sale securities
Yield, within 1 year	0.00%	0.00%
Yield, 5 to 10 years	0.16%	0.22%
Yield, over 10 years	5.85%	5.85%
Agency pass-through certificates
Amortized Cost, Available-for-sale securities
Amortized cost, without single maturity date	$ 603,800	$ 585,121
Gross Unrealized Gains / Losses, Available-for-sale securities
Gross unrealized gains, without single maturity date	4,936	23,717
Gross unrealized losses, without single maturity date	(10,833)	(2,011)
Fair Value, Available-for-sale securities
Fair value, without single maturity date	$ 597,903	$ 606,827
Yield, Available-for-sale securities
Yield, without single maturity date	2.60%	2.60%
Amortized Cost, Held-to-maturity securities
Held-to-maturity securities, amortized cost	$ 301,221	$ 366,025
Gross Unrealized Gains / Losses, Held-to-maturity securities
Held-to-maturity securities, gross unrealized gains	170	13,522
Held-to-maturity securities, gross unrealized losses	(7,037)	0
Fair Value, Held-to-maturity securities
Held-to-maturity securities, fair value	$ 294,354	$ 379,547
Yield, Held-to-maturity securities
Held-to-maturity securities, yield	3.16%	3.17%

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Available-for-sale securities purchased	$ 124,651,000	$ 522,454,000
Proceeds from sales of available-for-sale securities	4,510,000	0
Held-to-maturity securities purchased	0	0
Proceeds from sale of held-to-maturity securities	$ 0	$ 0
Term of contractual due dates of substantially all mortgage-backed securities (in years)	10 years
Accrued interest for available-for-sale securities	$ 3,448,000		$ 3,458,000
Accrued interest for held-to-maturity securities	776,000		$ 944,000
Consumer loans | Single-family residential
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Foreclosed residential real estate properties held as REO	166,000
Real estate acquired through foreclosure	$ 4,780,000

Fair Value Measurements - Secur

Fair Value Measurements - Securities in Unrealized Loss Positions (Details) $ in Thousands	Mar. 31, 2022USD ($)security	Sep. 30, 2021USD ($)security
Debt Securities, Available-for-sale [Line Items]
Number of debt securities with unrealized loss | security	131	31
Available-for-sale securities
Less than 12 months, unrealized gross losses	$ (7,667)	$ (1,584)
12 months or more, unrealized gross losses	(15,704)	(1,056)
Total unrealized gross losses	(23,371)	(2,640)
Less than 12 months, fair value	551,598	52,397
12 months or more, fair value	236,765	102,324
Total, fair value	788,363	154,721
Held-to-maturity securities
Less than 12 months, unrealized gross losses	(7,037)	0
Less than 12 months, fair value	291,911	0
12 months or more, unrealized gross losses	0	0
12 months or more, fair value	0	0
Total unrealized gross losses	(7,037)	0
Total, fair value	291,911	0
Less than 12 months, unrealized gross losses	(14,704)	(1,584)
Less than 12 months, fair value	843,509	52,397
12 months or more, unrealized gross losses	(15,704)	(1,056)
12 months or more, fair value	236,765	102,324
Total unrealized gross losses	(30,408)	(2,640)
Total fair value	1,080,274	154,721
Corporate debt securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	0
12 months or more, unrealized gross losses	(9,482)
Total unrealized gross losses	(9,482)
Less than 12 months, fair value	0
12 months or more, fair value	105,528
Total, fair value	105,528
Municipal bonds due
Available-for-sale securities
Less than 12 months, unrealized gross losses	(156)
12 months or more, unrealized gross losses	0
Total unrealized gross losses	(156)
Less than 12 months, fair value	5,610
12 months or more, fair value	0
Total, fair value	5,610
U.S. government and agency securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	(659)
12 months or more, unrealized gross losses	0
Total unrealized gross losses	(659)
Less than 12 months, fair value	34,697
12 months or more, fair value	0
Total, fair value	34,697
Asset-backed securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	(1,269)	(15)
12 months or more, unrealized gross losses	(972)	(614)
Total unrealized gross losses	(2,241)	(629)
Less than 12 months, fair value	277,125	4,639
12 months or more, fair value	67,792	70,058
Total, fair value	344,917	74,697
Mortgage-backed securities
Available-for-sale securities
Less than 12 months, unrealized gross losses	(5,583)	(1,569)
12 months or more, unrealized gross losses	(5,250)	(442)
Total unrealized gross losses	(10,833)	(2,011)
Less than 12 months, fair value	234,166	47,758
12 months or more, fair value	63,445	32,266
Total, fair value	$ 297,611	$ 80,024

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities - Summary of Fair Value, Notional Amount and Balance Sheet Classification (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Other assets
Derivatives, Fair Value [Line Items]
Notional amount	$ 2,085,830	$ 1,644,355
Derivative assets, fair value	151,845	53,425
Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	658,039	1,159,033
Derivative liabilities, fair value	27,391	14,801
Client swap program hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	615,830	644,355
Derivative assets, fair value	27,353	10,983
Client swap program hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	615,830	644,355
Derivative liabilities, fair value	27,353	10,983
Commercial loan fair value hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	0	0
Derivative assets, fair value	0	0
Commercial loan fair value hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	42,209	44,678
Derivative liabilities, fair value	38	2,177
Mortgage loan fair value hedges
Derivatives, Fair Value [Line Items]
Notional amount	470,000
Mortgage loan fair value hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	470,000	0
Derivative assets, fair value	19,281	0
Mortgage loan fair value hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	0	470,000
Derivative liabilities, fair value	0	1,641
Borrowings cash flow hedges | Other assets
Derivatives, Fair Value [Line Items]
Notional amount	1,000,000	1,000,000
Derivative assets, fair value	105,211	42,442
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	Mar. 31, 2022	Sep. 30, 2021
Derivatives, Fair Value [Line Items]
Carrying value of hedged items	$ 1,272,018	$ 1,515,487
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	(18,845)	4,215
Loans Receivable
Derivatives, Fair Value [Line Items]
Carrying value of hedged items	1,272,018	1,515,487
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	(18,845)	4,215
Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	658,039	1,159,033
Mortgage loan fair value hedges
Derivatives, Fair Value [Line Items]
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	(19,000)	1,900
Notional amount	470,000
Hedged asset, discontinued		$ 30,000
Hedged asset, discontinued, percentage		30.00%
Hedged asset, discontinued, last layer hedge		$ 100,000
Mortgage loan fair value hedges | Loans Receivable
Derivatives, Fair Value [Line Items]
Carrying value of hedged items	1,230,000	1,469,000
Mortgage loan fair value hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	0	470,000
Commercial loan fair value hedges
Derivatives, Fair Value [Line Items]
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	100	2,400
Hedged asset, discontinued, last layer hedge		46,000
Commercial loan fair value hedges | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Cumulative gain (loss) fair value hedge adjustment included in carrying amount of hedged items	1,000
Commercial loan fair value hedges | Loans Receivable
Derivatives, Fair Value [Line Items]
Carrying value of hedged items	42,000	47,000
Commercial loan fair value hedges | Other liabilities
Derivatives, Fair Value [Line Items]
Notional amount	$ 42,209	$ 44,678

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Derivative [Line Items]
Gain (loss) on termination of hedging derivatives	$ 0	$ 14,110	$ 0	$ 14,110
Interest Rate Swap | Minimum
Derivative [Line Items]
Derivative, maturities			2 years
Interest Rate Swap | Maximum
Derivative [Line Items]
Derivative, maturities			8 years
Interest Rate Swap | Weighted average
Derivative [Line Items]
Derivative, maturities			7 years
Interest Rate Swap One | Designated as Hedging Instrument | Cash flow hedging
Derivative [Line Items]
Notional amount of derivative terminated				$ 200,000
Effective interest rate of derivative terminated				1.37%
Interest Rate Swap Two | Designated as Hedging Instrument | Cash flow hedging
Derivative [Line Items]
Notional amount of derivative terminated				$ 200,000
Effective interest rate of derivative terminated				0.79%
Interest Rate Swap Three | Designated as Hedging Instrument | Cash flow hedging
Derivative [Line Items]
Notional amount of derivative terminated				$ 150,000
Effective interest rate of derivative terminated				2.91%

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities - Impact of Derivative Instruments on AOCI (Details) - Pay fixed/receive floating swaps on borrowings cash flow hedges - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Derivative [Line Items]
Pay fixed/receive floating swaps on borrowings cash flow hedges	$ 56,323	$ 70,565	$ 62,769	$ 90,683
Reclassification adjustment of net (gain)/loss included in net income	0	(14,110)	0	(14,110)
Total pre-tax gain/(loss) recognized in AOCI	$ 56,323	$ 56,455	$ 62,769	$ 76,573

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		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Interest income on loans receivable	$ 139,260	$ 132,757	$ 277,769	$ 266,428
Interest expense on FHLB advances	(7,525)	(11,991)	(15,368)	(25,189)
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	(1,199)	(1,563)	(2,570)	(3,104)
Recognized on derivatives	18,561	17,491	23,061	22,078
Recognized on hedged items	(18,586)	(17,377)	(23,061)	(21,833)
Net income/(expense) recognized on fair value hedges	(1,224)	(1,449)	(2,570)	(2,859)
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	1,715	3,066	3,736	6,664
Reclassification adjustment of net (gain)/loss included in net income	0	14,110	0	14,110
Net income/(expense) recognized on cash flow hedges	$ 1,715	$ 17,176	$ 3,736	$ 20,774

Derivatives and Hedging Activ_8

Derivatives and Hedging Activities - Impact of Client Swap Program that are Not Designated in Accounting Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Client swap program hedges
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 0	$ 0	$ 0	$ 0
Other noninterest income | Pay fixed/receive floating swap
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	33,298	40,929	38,337	53,305
Other noninterest income | Receive fixed/pay floating swap
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ (33,298)	$ (40,929)	$ (38,337)	$ (53,305)

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Details)	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue streams percentage, contract with customer	6.00%	5.70%

Commitment and Contingencies (D

Commitment and Contingencies (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans in process	$ 2,440,430	$ 2,232,836
Off-balance-sheet credit reserve	30,000	27,500
Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans in process	$ 4,295,025	$ 3,804,444