ESSA Bancorp (ESSA) 10-Q 10 May 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2018	May 08, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Trading Symbol	ESSA
Entity Registrant Name	ESSA Bancorp, Inc.
Entity Central Index Key	1,382,230
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		11,766,509

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
ASSETS
Cash and due from banks	$ 29,112	$ 36,008
Interest-bearing deposits with other institutions	5,692	5,675
Total cash and cash equivalents	34,804	41,683
Certificates of deposit	500	500
Investment securities available for sale, at fair value	377,375	390,452
Loans receivable (net of allowance for loan losses of $10,510 and $9,365)	1,291,262	1,236,681
Regulatory stock, at cost	17,234	13,832
Premises and equipment, net	15,604	16,234
Bank-owned life insurance	38,130	37,626
Foreclosed real estate	1,279	1,424
Intangible assets, net	1,565	1,844
Goodwill	13,801	13,801
Deferred income taxes	8,299	10,422
Other assets	21,071	20,719
TOTAL ASSETS	1,820,924	1,785,218
LIABILITIES
Deposits	1,239,353	1,274,861
Short-term borrowings	241,345	137,446
Other borrowings	139,434	174,168
Advances by borrowers for taxes and insurance	12,188	5,163
Other liabilities	11,226	10,853
TOTAL LIABILITIES	1,643,546	1,602,491
STOCKHOLDERS’ EQUITY
Preferred Stock ($0.01 par value; 10,000,000 shares authorized, none issued)
Common stock ($0.01 par value; 40,000,000 shares authorized, 18,133,095 issued; 11,732,222 and 11,596,263 outstanding at March 31, 2018 and September 30, 2017, respectively)	181	181
Additional paid in capital	180,466	180,764
Unallocated common stock held by the Employee Stock Ownership Plan (ESOP)	(8,488)	(8,720)
Retained earnings	90,179	91,147
Treasury stock, at cost; 6,400,873 and 6,536,832 shares outstanding at March 31, 2018 and September 30, 2017, respectively	(78,225)	(79,891)
Accumulated other comprehensive loss	(6,735)	(754)
TOTAL STOCKHOLDERS’ EQUITY	177,378	182,727
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 1,820,924	$ 1,785,218

Consolidated Balance Sheet (Un3

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Statement Of Financial Position [Abstract]
Allowance for loan losses	$ 10,510	$ 9,365
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	10,000,000	10,000,000
Preferred Stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	18,133,095	18,133,095
Common stock, shares outstanding	11,732,222	11,596,263
Treasury stock, shares outstanding	6,400,873	6,536,832

Consolidated Statement of Opera

Consolidated Statement of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
INTEREST INCOME
Loans receivable, including fees	$ 12,953	$ 11,799	$ 25,736	$ 24,050
Investment securities:
Taxable	2,186	2,043	4,244	3,917
Exempt from federal income tax	285	303	573	612
Other investment income	423	234	670	450
Total interest income	15,847	14,379	31,223	29,029
INTEREST EXPENSE
Deposits	2,359	2,069	4,736	4,081
Short-term borrowings	951	296	1,535	547
Other borrowings	602	710	1,249	1,465
Total interest expense	3,912	3,075	7,520	6,093
NET INTEREST INCOME	11,935	11,304	23,703	22,936
Provision for loan losses	1,100	750	2,100	1,500
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	10,835	10,554	21,603	21,436
NONINTEREST INCOME
Service fees on deposit accounts	821	813	1,704	1,677
Services charges and fees on loans	299	273	668	627
Trust and investment fees	237	214	477	364
Gain on sale of investments, net	75		75
Earnings on Bank-owned life insurance	249	256	504	519
Insurance commissions	204	203	375	396
Other	60	25	111	58
Total noninterest income	1,945	1,784	3,914	3,641
NONINTEREST EXPENSE
Compensation and employee benefits	5,900	6,056	11,908	12,233
Occupancy and equipment	1,186	1,190	2,371	2,281
Professional fees	626	835	1,192	1,580
Data processing	888	931	1,817	1,865
Advertising	201	241	359	546
Federal Deposit Insurance Corporation (FDIC) premiums	256	213	445	400
Loss (Gain) on foreclosed real estate	32	(5)	(4)	(101)
Amortization of intangible assets	135	164	279	327
Other	764	879	1,903	1,775
Total noninterest expense	9,988	10,504	20,270	20,906
Income before income taxes	2,792	1,834	5,247	4,171
Income taxes	529	203	4,622	603
NET INCOME	$ 2,263	$ 1,631	$ 625	$ 3,568
Earnings per share
Basic	$ 0.21	$ 0.15	$ 0.06	$ 0.34
Diluted	0.21	0.15	0.06	0.34
Dividends per share	$ 0.09	$ 0.09	$ 0.18	$ 0.18

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,263	$ 1,631	$ 625	$ 3,568
Investment securities available for sale:
Unrealized holding gain (loss)	(6,452)	1,184	(8,403)	(9,048)
Tax effect	1,352	(403)	2,015	3,076
Reclassification of gains recognized in net income	(75)		(75)
Tax effect	18		18
Net of tax amount	(5,157)	781	(6,445)	(5,972)
Pension plan adjustment:
Related to freezing pension		7,143		7,143
Tax effect		(2,429)		(2,429)
Reclassification of gains recognized in net income		23		159
Tax effect		(10)		(56)
Net of tax amount		4,727		4,817
Derivative and hedging activities adjustments:
Changes in unrealized holding gains on derivatives included in net income	738	40	1,195	1,092
Tax effect	(151)	(15)	(307)	(473)
Reclassification adjustment for gains on derivatives included in net income	(76)	(5)	(99)	6
Tax effect	13	3	21	(2)
Net of tax amount	524	23	810	623
Total other comprehensive (loss) income	(4,633)	5,531	(5,635)	(532)
Comprehensive (loss) income	$ (2,370)	$ 7,162	$ (5,010)	$ 3,036

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Unallocated Common Stock Held by the ESOP [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Sep. 30, 2016							$ (1,832)
Net income	$ 3,568
Other comprehensive loss	(532)						(532)
Ending Balance at Mar. 31, 2017							(2,364)
Beginning Balance at Dec. 31, 2016							(7,895)
Net income	1,631
Other comprehensive loss	5,531						5,531
Ending Balance at Mar. 31, 2017							(2,364)
Beginning Balance at Sep. 30, 2017	$ 182,727	$ 181	$ 180,764	$ (8,720)	$ 91,147	$ (79,891)	(754)
Beginning Balance, Shares at Sep. 30, 2017	11,596,263	11,596,263
Net income	$ 625				625
Other comprehensive loss	(5,635)						(5,635)
Reclassification of certain income tax effects from accumulated other comprehensive income					346		(346)
Cash dividends declared ($0.18 per share)	(1,939)				(1,939)
Stock based compensation	184		184
Allocation of ESOP stock	362		130	232
Allocation of treasury shares to incentive plan			(281)			281
Allocation of treasury shares to incentive plan, Shares		22,994
Stock options exercised	$ 1,054		(331)			1,385
Stock options exercised, Shares	196,848	112,965
Ending Balance at Mar. 31, 2018	$ 177,378	$ 181	180,466	(8,488)	90,179	(78,225)	(6,735)
Ending Balance, Shares at Mar. 31, 2018	11,732,222	11,732,222
Beginning Balance at Dec. 31, 2017							(1,756)
Net income	$ 2,263
Other comprehensive loss	(4,633)						(4,979)
Reclassification of certain income tax effects from accumulated other comprehensive income							(346)
Ending Balance at Mar. 31, 2018	$ 177,378	$ 181	$ 180,466	$ (8,488)	$ 90,179	$ (78,225)	$ (6,735)
Ending Balance, Shares at Mar. 31, 2018	11,732,222	11,732,222

Consolidated Statement of Chan7

Consolidated Statement of Changes in Stockholders' Equity (Unaudited) (Parenthetical)	6 Months Ended
	Mar. 31, 2018$ / shares
Cash dividends declared, per share	$ 0.18
Retained Earnings [Member]
Cash dividends declared, per share	$ 0.18

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING ACTIVITIES
Net income	$ 625	$ 3,568
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	2,100	1,500
Provision for depreciation and amortization	599	685
Amortization and accretion of discounts and premiums, net	2,227	2,216
Net gain on sale of investment securities	(75)
Compensation expense on ESOP	362	344
Stock based compensation	184	145
Increase in accrued interest receivable	(130)	(160)
Increase (decrease) in accrued interest payable	34	(183)
Earnings on bank-owned life insurance	(504)	(519)
Deferred federal income taxes	3,525	170
(Decrease) increase in accrued pension liability	(255)	297
Gain on foreclosed real estate, net	(4)	(101)
Amortization of intangible assets	279	327
Other, net	1,910	3,963
Net cash provided by operating activities	10,877	12,252
INVESTING ACTIVITIES
Certificates of deposit maturities		250
Investment securities available for sale:
Proceeds from sale of investment securities	22,074
Proceeds from principal repayments and maturities	32,270	33,192
Purchases	(50,617)	(48,049)
(Increase) decrease in loans receivable, net	(58,649)	5,792
Redemption of regulatory stock	9,034	11,413
Purchase of regulatory stock	(12,436)	(9,911)
Proceeds from sale of foreclosed real estate	837	1,557
Purchase of premises, equipment and software	(66)	(383)
Net cash used for investing activities	(57,553)	(6,139)
FINANCING ACTIVITIES
(Decrease) increase in deposits, net	(35,508)	23,555
Net increase (decrease) in short-term borrowings	103,899	(8,509)
Proceeds from other borrowings	25,100	17,597
Repayment of other borrowings	(59,834)	(49,030)
Increase in advances by borrowers for taxes and insurance	7,025	4,159
Exercising of stock options	1,054	807
Dividends on common stock	(1,939)	(1,907)
Net cash provided by (used for) financing activities	39,797	(13,328)
Decrease in cash and cash equivalents	(6,879)	(7,215)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	41,683	43,658
CASH AND CASH EQUIVALENTS AT END OF YEAR	34,804	36,443
Cash Paid:
Interest	7,486	6,276
Income taxes	(2)	(389)
Noncash items:
Transfers from loans to foreclosed real estate	688	2,112
Unrealized holding loss	$ (8,478)	(9,048)
Pension Plan curtailment		$ 7,143

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	6 Months Ended
	Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	1. Nature of Operations and Basis of Presentation The consolidated financial statements include the accounts of ESSA Bancorp, Inc. (the “Company”), its wholly owned subsidiary, ESSA Bank & Trust (the “Bank”), and the Bank’s wholly owned subsidiaries, ESSACOR Inc.; Pocono Investments Company; ESSA Advisory Services, LLC; Integrated Financial Corporation; and Integrated Abstract Incorporated, a wholly owned subsidiary of Integrated Financial Corporation. The primary purpose of the Company is to act as a holding company for the Bank. On November 6, 2014, the Company converted its status from a savings and loan holding company to a bank holding company. In addition, the Bank converted from a Pennsylvania-chartered savings association to a Pennsylvania-chartered savings bank. The Bank’s primary business consists of the taking of deposits and granting of loans to customers generally in Monroe, Northampton, Lehigh, Delaware, Chester, Montgomery, Lackawanna, and Luzerne Counties, Pennsylvania. The Bank is subject to regulation and supervision by the Pennsylvania Department of Banking and Securities and the Federal Deposit Insurance Corporation (the “FDIC”). The investment in the Bank on the parent company’s financial statements is carried at the parent company’s equity in the underlying net assets. ESSACOR, Inc. is a Pennsylvania corporation that has been used to purchase properties at tax sales that represent collateral for delinquent loans of the Bank and is currently inactive. Pocono Investment Company is a Delaware corporation formed as an investment company subsidiary to hold and manage certain investments, including certain intellectual property. ESSA Advisory Services, LLC is a Pennsylvania limited liability company owned 100 percent by ESSA Bank & Trust. ESSA Advisory Services, LLC is a full-service insurance benefits consulting company offering group services such as health insurance, life insurance, short-term and long-term disability, dental, vision, and 401(k) retirement planning as well as individual health products. Integrated Financial Corporation is a Pennsylvania corporation that provided investment advisory services to the general public and is currently inactive. Integrated Abstract Incorporated is a Pennsylvania corporation that provided title insurance services and is currently inactive. All significant intercompany accounts and transactions have been eliminated in consolidation. The unaudited consolidated financial statements reflect all adjustments, which in the opinion of management, are necessary for a fair presentation of the results of the interim periods and are of a normal and recurring nature. Operating results for the three and six month periods ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending September 30, 2018.

Earnings per Share

Earnings per Share	6 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per Share	2. Earnings per Share The following table sets forth the composition of the weighted-average common shares (denominator) used in the basic and diluted earnings per share computation for the three and six month periods ended March 31, 2018 and 2017. Three Months Ended Six Months Ended March 31, March 31, March 31, March 31, 2018 2017 2018 2017 Weighted-average common shares outstanding 18,133,095 18,133,095 18,133,095 18,133,095 Average treasury stock shares (6,459,392 ) (6,618,067 ) (6,490,961 ) (6,670,049 ) Average unearned ESOP shares (843,010 ) (888,285 ) (848,729 ) (894,004 ) Average unearned non-vested shares (34,340 ) (33,746 ) (44,318 ) (42,958 ) Weighted average common shares and common stock equivalents used to calculate basic earnings per share 10,796,353 10,592,997 10,749,087 10,526,084 Additional common stock equivalents (non-vested stock) used to calculate diluted earnings per share 347 1,646 143 — Additional common stock equivalents (stock options) used to calculate diluted earnings per share 25,409 97,317 31,149 91,157 Weighted average common shares and common stock equivalents used to calculate diluted earnings per share 10,822,109 10,691,960 10,780,379 10,617,241 At March 31, 2018 there were 53,313 shares of nonvested stock outstanding at an average weighted price of $15.24 per share that were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive. At March 31, 2017 there were 53,371 shares of nonvested stock outstanding at an average weighted price of $11.77 per share that were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive.

Use of Estimates in the Prepara

Use of Estimates in the Preparation of Financial Statements	6 Months Ended
	Mar. 31, 2018
Text Block [Abstract]
Use of Estimates in the Preparation of Financial Statements	3. Use of Estimates in the Preparation of Financial Statements The accounting principles followed by the Company and its subsidiaries and the methods of applying these principles conform to U.S. generally accepted accounting principles (“GAAP”) and to general practice within the banking industry. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the Consolidated Balance Sheet date and related revenues and expenses for the period. Actual results could differ from those estimates.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Mar. 31, 2018
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	4. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers Topic 606 In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606). Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Deferral of the Effective Date In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment In February 2017, the FASB issued ASU 2017-05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20). In March 2017, the FASB issued ASU 2017-07, Compensation—Retirement Benefits (Topic 715) In March 2017, the FASB issued ASU 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20). The amendments in this Update shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public business entities, the amendments in this Update are effective for fiscal years, and interim periods within those fiscal years, beg For all other entities, the amendments are effective for fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity should apply the amendments in this Update on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Additionally, in the period of adoption, an entity should provide disclosures about a change in accounting principle. This Update is not expected to have a significant impact on the Company’s financial statements. In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation (Topic 718) . In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivative and Hedging (Topic 815) Debt—Debt with Conversion and Other Options In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 850) In January 2018, the FASB issued ASU 2018-01, Leases (Topic 842) In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220) In February 2018, the FASB issued ASU 2018-03, Technical Corrections and Improvements to Financial Instruments—Overall (Subtopic 825-10) Fair Value Measurement Derivatives and Hedging—Embedded Derivatives Financial Instruments—Overall Financial Services— Insurance

Investment Securities

Investment Securities	6 Months Ended
	Mar. 31, 2018
Investments Debt And Equity Securities [Abstract]
Investment Securities	5. The amortized cost, gross unrealized gains and losses, and fair value of investment securities available for sale are summarized as follows (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 136,157 $ 15 $ (3,880 ) $ 132,292 Freddie Mac 97,336 5 (3,113 ) 94,228 Governmental National Mortgage Association Securities 20,845 — (657 ) 20,188 Total mortgage-backed securities 254,338 20 (7,650 ) 246,708 Obligations of states and political subdivisions 52,046 621 (1,305 ) 51,362 U.S. government agency securities 13,191 26 (109 ) 13,108 Corporate obligations 45,748 242 (1,002 ) 44,988 Other debt securities 21,910 3 (729 ) 21,184 Total debt securities 387,233 912 (10,795 ) 377,350 Equity securities - financial services 25 — — 25 Total $ 387,258 $ 912 $ (10,795 ) $ 377,375 September 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 119,333 $ 207 $ (1,203 ) $ 118,337 Freddie Mac 98,668 177 (808 ) 98,037 Governmental National Mortgage Association 17,609 43 (203 ) 17,449 Total mortgage-backed securities 235,610 427 (2,214 ) 233,823 Obligations of states and political subdivisions 64,382 1,522 (546 ) 65,358 U.S. government agency securities 18,615 61 (5 ) 18,671 Corporate obligations 49,025 335 (618 ) 48,742 Other debt securities 24,200 47 (414 ) 23,833 Total debt securities 391,832 2,392 (3,797 ) 390,427 Equity securities - financial services 25 — — 25 Total $ 391,857 $ 2,392 $ (3,797 ) $ 390,452 The amortized cost and fair value of debt securities at March 31, 2018, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties (in thousands): Available For Sale Amortized Cost Fair Value Due in one year or less $ 1,748 $ 1,750 Due after one year through five years 34,694 34,396 Due after five years through ten years 100,607 98,495 Due after ten years 250,184 242,709 Total $ 387,233 $ 377,350 For the three and six months ended March 31, 2018, the Company realized gross gains of $300,000 and gross losses of $225,000 on proceeds from the sale of investment securities of $22.1 million. For the three and six months ended March 31, 2017, the Company realized no gross gains or gross losses on proceeds from the sale on investment securities. The following tables show the Company’s gross unrealized losses and fair value, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position (dollars in thousands): March 31, 2018 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 90 $ 84,342 $ (1,691 ) $ 45,723 $ (2,189 ) $ 130,065 $ (3,880 ) Freddie Mac 68 61,564 (1,553 ) 31,808 (1,560 ) 93,372 (3,113 ) Governmental National Mortgage Association 17 13,429 (309 ) 6,759 (348 ) 20,188 (657 ) Obligations of states and political subdivisions 28 11,431 (217 ) 19,765 (1,088 ) 31,196 (1,305 ) U.S. government agency securities 4 8,718 (109 ) — — 8,718 (109 ) Corporate obligations 29 20,338 (350 ) 9,465 (652 ) 29,803 (1,002 ) Other debt securities 19 2,085 (34 ) 17,858 (695 ) 19,943 (729 ) Total 255 $ 201,907 $ (4,263 ) $ 131,378 $ (6,532 ) $ 333,285 $ (10,795 ) September 30, 2017 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 55 $ 61,852 $ (558 ) $ 20,679 $ (645 ) $ 82,531 $ (1,203 ) Freddie Mac 39 38,913 (354 ) 16,427 (454 ) 55,340 (808 ) Governmental National Mortgage Association 11 6,669 (41 ) 6,903 (162 ) 13,572 (203 ) Obligations of states and political subdivisions 25 10,944 (59 ) 17,425 (487 ) 28,369 (546 ) U.S. government agency securities 3 8,995 (5 ) — — 8,995 (5 ) Corporate obligations 22 15,119 (104 ) 8,032 (514 ) 23,151 (618 ) Other debt securities 19 7,141 (104 ) 13,806 (310 ) 20,947 (414 ) Total 174 $ 149,633 $ (1,225 ) $ 83,272 $ (2,572 ) $ 232,905 $ (3,797 ) The Company’s investment securities portfolio contains unrealized losses on securities, including mortgage-related instruments issued or backed by the full faith and credit of the United States government, or generally viewed as having the implied guarantee of the U.S. government, other mortgage backed securities, debt obligations of a U.S. state or political subdivision, U.S. government agency securities, corporate obligations and other debt securities. The Company reviews its position quarterly and has asserted that at March 31, 2018, the declines outlined in the above table represent temporary declines and the Company would not be required to sell the above securities before their anticipated recovery in market value. The Company has concluded that any impairment of its investment securities portfolio is not other than temporary but is the result of interest rate changes that are not expected to result in the non-collection of principal and interest during the period.

Loans Receivable, Net and Allow

Loans Receivable, Net and Allowance for Loan Losses	6 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Loans Receivable, Net and Allowance for Loan Losses	6. Loans Receivable, Net and Allowance for Loan Losses Loans receivable consist of the following (in thousands): March 31, 2018 September 30, 2017 Real estate loans: Residential $ 583,926 $ 586,708 Construction 4,072 3,097 Commercial 383,561 318,323 Commercial 49,273 44,129 Obligations of states and political subdivisions 55,615 58,079 Home equity loans and lines of credit 44,247 46,219 Auto Loans 178,420 186,646 Other 2,658 2,845 1,301,772 1,246,046 Less allowance for loan losses 10,510 9,365 Net loans $ 1,291,262 $ 1,236,681 Purchased loans acquired in a business combination are recorded at fair value on their purchase date without a carryover of the related allowance for loan losses. Changes in the accretable yield for purchased credit-impaired loans were as follows, since acquisition, for the three and six months ended March 31, 2018 and 2017 (in thousands): For the Three Months Ended March 31, 2018 2017 Balance at beginning of period $ 755 $ 453 Reclassification, new additions and other 85 82 Accretion (266 ) (75 ) Balance at end of period $ 574 $ 460 For the Six Months Ended March 31, 2018 2017 Balance at beginning of period $ 471 $ 478 Reclassification, new additions and other 681 118 Accretion (578 ) (136 ) Balance at end of period $ 574 $ 460 The following table presents additional information regarding loans acquired and accounted for in accordance with ASC 310-30 (in thousands): March 31, 2018 September 30, 2017 Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Outstanding balance $ 4,852 $ 5,490 Carrying amount $ 4,480 $ 4,388 The following tables show the amount of loans in each category that were individually and collectively evaluated for impairment at the dates indicated (in thousands): Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment March 31, 2018 Real estate loans: Residential $ 583,926 $ 5,190 $ — $ 578,736 Construction 4,072 — — 4,072 Commercial 383,561 6,803 3,900 372,858 Commercial 49,273 1,142 252 47,879 Obligations of states and political subdivisions 55,615 — — 55,615 Home equity loans and lines of credit 44,247 198 328 43,721 Auto loans 178,420 558 — 177,862 Other 2,658 27 — 2,631 Total $ 1,301,772 $ 13,918 $ 4,480 $ 1,283,374 Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment September 30, 2017 Real estate loans: Residential $ 586,708 $ 6,202 $ — $ 580,506 Construction 3,097 — — 3,097 Commercial 318,323 7,211 3,775 307,337 Commercial 44,129 1,385 283 42,461 Obligations of states and political sub divisions 58,079 — — 58,079 Home equity loans and lines of credit 46,219 176 330 45,713 Auto loans 186,646 572 — 186,074 Other 2,845 30 — 2,815 Total $ 1,246,046 $ 15,576 $ 4,388 $ 1,226,082 The Company maintains a loan review system that allows for a periodic review of our loan portfolio and the early identification of potential impaired loans. Such system takes into consideration, among other things, delinquency status, size of loans, type and market value of collateral and financial condition of the borrowers. Specific loan loss allowances are established for identified losses based on a review of such information. A loan evaluated for impairment is considered to be impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement. All loans identified as impaired are evaluated independently. The Company does not aggregate such loans for evaluation purposes. Impairment is measured on a loan-by-loan basis for commercial and construction loans by the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral if the loan is collateral-dependent. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not separately identify individual consumer and residential mortgage loans for impairment disclosures, unless such loans are part of a larger relationship that is impaired, or are classified as a troubled debt restructuring. A loan is considered to be a troubled debt restructuring (“TDR”) loan when the Company grants a concession to the borrower that it would not otherwise consider because of the borrower’s financial condition. Such concessions include the reduction of interest rates, forgiveness of principal or interest, or other modifications of interest rates that are less than the current market rate for new obligations with similar risk. TDR loans that are in compliance with their modified terms and that yield a market rate at the time of modification may be removed from TDR status after one year of performance. The following tables include the recorded investment and unpaid principal balances for impaired loans with the associated allowance amount at the dates indicated, if applicable (in thousands): Recorded Investment Unpaid Principal Balance Associated Allowance March 31, 2018 With no specific allowance recorded: Real estate loans Residential $ 3,879 $ 5,193 $ — Construction — — — Commercial 6,785 8,729 — Commercial 1,142 1,397 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 172 186 — Auto loans 214 420 — Other 27 34 — Total 12,219 15,959 — With an allowance recorded: Real estate loans Residential 1,311 1,561 160 Construction — — — Commercial 18 22 12 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 26 27 2 Auto loans 344 355 130 Other — — — Total 1,699 1,965 304 Total: Real estate loans Residential 5,190 6,754 160 Construction — — — Commercial 6,803 8,751 12 Commercial 1,142 1,397 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 198 213 2 Auto loans 558 775 130 Other 27 34 — Total Impaired Loans $ 13,918 $ 17,924 $ 304 Recorded Investment Unpaid Principal Balance Associated Allowance September 30, 2017 With no specific allowance recorded: Real Estate Loans Residential $ 4,392 $ 5,730 $ — Construction — — — Commercial 7,191 9,396 — Commercial 1,385 1,575 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 176 258 — Auto Loans 123 237 — Other 30 36 — Total 13,297 17,232 — With an allowance recorded: Real Estate Loans Residential 1,810 2,264 154 Construction — — — Commercial 20 1,193 19 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto Loans 449 468 172 Other — — — Total 2,279 3,925 345 Total: Real Estate Loans Residential 6,202 7,994 154 Construction — — — Commercial 7,211 10,589 19 Commercial 1,385 1,575 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 176 258 — Auto Loans 572 705 172 Other 30 36 — Total Impaired Loans $ 15,576 $ 21,157 $ 345 The following tables represent the average recorded investments in the impaired loans and the related amount of interest recognized during the time within the period that the impaired loans were impaired (in thousands): For the Three Months Ended March 31, 2018 2017 2018 2017 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 4,180 $ 5,573 $ 6 $ 9 Construction — — — — Commercial 6,789 9,218 69 67 Commercial 1,178 1,637 24 29 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 203 202 — — Auto loans 208 102 — — Other 28 8 — — Total 12,586 16,740 99 105 With an allowance recorded: Real estate loans Residential 1,256 1,985 — — Construction — — — — Commercial 19 341 — — Commercial — 100 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 12 5 — — Auto loans 231 291 — 2 Other — — — — Total 1,518 2,722 — 2 Total: Real estate loans Residential 5,436 7,558 6 9 Construction — — — — Commercial 6,808 9,559 69 67 Commercial 1,178 1,737 24 29 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 215 207 — — Auto loans 439 393 — 2 Other 28 8 — — Total Impaired Loans $ 14,104 $ 19,462 $ 99 $ 107 For the Six Months Ended March 31, 2018 2017 2018 2017 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 4,305 $ 6,049 $ 16 $ 21 Construction — — — — Commercial 6,897 9,890 141 172 Commercial 1,233 1,665 51 62 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 205 260 1 — Auto loans 172 119 1 — Other 29 8 — — Total 12,841 17,991 210 255 With an allowance recorded: Real estate loans Residential 1,392 2,025 — — Construction — — — — Commercial 19 345 — — Commercial — 59 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 7 4 — — Auto loans 247 253 — 6 Other — — — — Total 1,665 2,686 — 6 Total: Real estate loans Residential 5,697 8,074 16 21 Construction — — — — Commercial 6,916 10,235 141 172 Commercial 1,233 1,724 51 62 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 212 264 1 — Auto loans 419 372 1 6 Other 29 8 — — Total Impaired Loans $ 14,506 $ 20,677 $ 210 $ 261 The Company uses a ten-point internal risk-rating system to monitor the credit quality of the overall loan portfolio. The first six categories are considered not criticized and are aggregated as Pass-rated. The criticized rating categories utilized by management generally follow bank regulatory definitions. The Special Mention category includes assets that are fundamentally sound yet exhibit potentially unacceptable credit risk or deteriorating trends or characteristics which, if left uncorrected, may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. Loans in the Substandard category have well-defined weaknesses that jeopardize the liquidation of the debt and have a distinct possibility that some loss will be sustained if the weaknesses are not corrected. All loans more than 90 days past due are considered Substandard. Loans in the Doubtful category have all the weaknesses inherent in loans classified as Substandard with the added characteristic that their weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. Loans in the Loss category are considered uncollectible and of little value that their continuance as bankable assets is not warranted. Certain residential real estate loans, construction loans, home equity loans and lines of credit, auto loans and other consumer loans are underwritten and structured using standardized criteria and characteristics, primarily payment performance, and are normally risk rated and monitored collectively on a monthly basis. These are typically loans to individuals in the consumer categories and are delineated as either performing or non-performing. To help ensure that risk ratings are accurate and reflect the present and future capacity of borrowers to repay a loan as agreed, the Bank has a structured loan rating process with several layers of internal and external oversight. Generally, consumer and residential mortgage loans are included in the Pass categories unless a specific action, such as bankruptcy, repossession, or death occurs to raise awareness of a possible credit event. The Bank’s Commercial Loan Officers are responsible for the timely and accurate risk rating recommendation for the loans in their portfolios at origination and on an ongoing basis. The Bank’s Commercial Loan Officers perform an annual review of all commercial relationships $750,000 or greater. Confirmation of the appropriate risk grade is included in the review on an ongoing basis. The Bank engages an external consultant to conduct loan reviews on at least a semi-annual basis. Generally, the external consultant reviews commercial relationships greater than $1,000,000 and/or all criticized relationships. Detailed reviews, including plans for resolution, are performed on loans classified as Substandard on a quarterly basis. Loans in the Special Mention and Substandard categories that are collectively evaluated for impairment are given separate consideration in the determination of the allowance. The following tables present the classes of the loan portfolio summarized by the aggregate Pass and the criticized categories of Special Mention, Substandard, and Doubtful or Loss within the internal risk rating system at March 31, 2018 and September 30, 2017 (in thousands): Pass Special Mention Substandard Doubtful or Loss Total March 31, 2018 Commercial real estate loans $ 364,292 $ 1,368 $ 17,901 $ — $ 383,561 Commercial 46,889 354 2,030 — 49,273 Obligations of states and political subdivisions 55,615 — — — 55,615 Total $ 466,796 $ 1,722 $ 19,931 $ — $ 488,449 Pass Special Mention Substandard Doubtful or Loss Total September 30, 2017 Commercial real estate loans $ 300,554 $ 3,376 $ 14,393 $ — $ 318,323 Commercial 40,996 32 3,101 — 44,129 Obligations of states and political subdivisions 58,079 — — — 58,079 Total $ 399,629 $ 3,408 $ 17,494 $ — $ 420,531 All other loans are underwritten and structured using standardized criteria and characteristics, primarily payment performance, and are normally risk rated and monitored collectively on a monthly basis. These are typically loans to individuals in the consumer categories and are delineated as either performing or non-performing. The following tables present the risk ratings in the consumer categories of performing and non-performing loans at March 31, 2018 and September 30, 2017 (in thousands): Performing Non- performing Purchased Credit Impaired Total March 31, 2018 Real estate loans: Residential $ 577,491 $ 6,435 $ — $ 583,926 Construction 4,072 — — 4,072 Home equity loans and lines of credit 43,615 304 328 44,247 Auto loans 177,698 722 — 178,420 Other 2,629 29 — 2,658 Total $ 805,505 $ 7,490 $ 328 $ 813,323 Performing Non- performing Purchased Impaired Credit Total September 30, 2017 Real estate loans: Residential $ 580,116 $ 6,592 $ — $ 586,708 Construction 3,097 — — 3,097 Home equity loans and lines of credit 45,576 313 330 46,219 Auto loans 185,910 736 — 186,646 Other 2,807 38 — 2,845 Total $ 817,506 $ 7,679 $ 330 $ 825,515 The Company further monitors the performance and credit quality of the loan portfolio by analyzing the age of the portfolio as determined by the length of time a recorded payment is past due. The following tables present the classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans as of March 31, 2018 and September 30, 2017 (in thousands): 31-60 Days 61-90 Days Greater than 90 Days Past Due and Total Purchased Credit Impaired Total Current Past Due Past Due Accruing Non­accrual Past Due Accruing Non­accrual Loans March 31, 2018 Real estate loans: Residential $ 575,286 $ 1,120 $ 1,085 $ — $ 6,435 $ 8,640 $ — $ — $ 583,926 Construction 4,072 — — — — — — — $ 4,072 Commercial 377,531 38 — — 2,092 2,130 261 3,639 $ 383,561 Commercial 48,910 — — — 111 111 — 252 $ 49,273 Obligations of states and political subdivisions 55,615 — — — — — — — $ 55,615 Home equity loans and lines of credit 43,456 159 — — 304 463 — 328 $ 44,247 Auto loans 176,631 951 116 — 722 1,789 — — $ 178,420 Other 2,629 — — — 29 29 — — $ 2,658 Total $ 1,284,130 $ 2,268 $ 1,201 $ — $ 9,693 $ 13,162 $ 261 $ 4,219 $ 1,301,772 31-60 Days 61-90 Days Greater than 90 Days Past Due and Total Purchased Credit Impaired Total Current Past Due Past Due Accruing Non­accrual Past Due Accruing Non­accrual Loans September 30, 2017 Real estate loans: Residential $ 577,034 $ 2,661 $ 421 $ — $ 6,592 $ 9,674 $ — $ — $ 586,708 Construction 3,097 — — — — — — — 3,097 Commercial 312,098 172 — — 2,278 2,450 612 3,163 318,323 Commercial 43,298 18 — — 530 548 — 283 44,129 Obligations of states and political subdivisions 58,079 — — — — — — — 58,079 Home equity loans and lines of credit 45,460 101 15 — 313 429 — 330 46,219 Auto loans 185,247 631 32 — 736 1,399 — — 186,646 Other 2,789 14 4 — 38 56 — — 2,845 Total $ 1,227,102 $ 3,597 $ 472 $ — $ 10,487 $ 14,556 $ 612 $ 3,776 $ 1,246,046 The allowance for loan losses is maintained at a level necessary to absorb loan losses that are both probable and reasonably estimable. Management, in determining the allowance for loan losses, considers the losses inherent in its loan portfolio and changes in the nature and volume of loan activities, along with the general economic and real estate market conditions. The allowance for loan losses consists of two elements: (1) an allocated allowance, which comprises allowances established on specific loans and class allowances based on historical loss experience and current trends, and (2) an allocated allowance based on general economic conditions and other risk factors in our markets and portfolios. We maintain a loan review system, which allows for a periodic review of our loan portfolio and the early identification of potential impaired loans. Such system takes into consideration, among other things, delinquency status, size of loans, type and market value of collateral and financial condition of the borrowers. General loan loss allowances are based upon a combination of factors including, but not limited to, actual loan loss experience, composition of the loan portfolio, current economic conditions, management’s judgment and losses which are probable and reasonably estimable. The allowance is increased through provisions charged against current earnings and recoveries of previously charged-off loans. Loans that are determined to be uncollectible are charged against the allowance. While management uses available information to recognize probable and reasonably estimable loan losses, future loss provisions may be necessary, based on changing economic conditions. Payments received on impaired loans generally are either applied against principal or reported as interest income, according to management’s judgment as to the collectability of principal. The allowance for loan losses as of March 31, 2018 was maintained at a level that represents management’s best estimate of losses inherent in the loan portfolio, and such losses were both probable and reasonably estimable. In addition, the FDIC and the Pennsylvania Department of Banking and Securities, as an integral part of their examination process, have periodically reviewed our allowance for loan losses. The banking regulators may require that we recognize additions to the allowance based on its analysis and review of information available to it at the time of its examination. Management reviews the loan portfolio on a quarterly basis using a defined, consistently applied process in order to make appropriate and timely adjustments to the allowance for loan losses (“ALL”). When information confirms all or part of specific loans to be uncollectible, these amounts are promptly charged off against the ALL. The following table summarizes changes in the primary segments of the ALL for the three and six month periods ended March 31, 2018 and 2017 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total ALL balance at December 31, 2017 $ 3,769 $ 33 $ 2,319 $ 1,054 $ 213 $ 449 $ 1,962 $ 21 $ 13 $ 9,833 Charge-offs (52 ) — (14 ) (5 ) — (6 ) (550 ) (15 ) — (642 ) Recoveries 3 — — — — 3 211 2 — 219 Provision 35 — 516 170 56 (45 ) 281 13 74 1,100 ALL balance at March 31, 2018 $ 3,755 $ 33 $ 2,821 $ 1,219 $ 269 $ 401 $ 1,904 $ 21 $ 87 $ 10,510 ALL balance at December 31, 2016 $ 4,450 $ 23 $ 795 $ 965 $ 234 $ 441 $ 2,062 $ 25 $ 347 $ 9,342 Charge-offs (290 ) — (128 ) (1 ) — (6 ) (544 ) — — (969 ) Recoveries 5 — — — — 2 232 4 — 243 Provision (35 ) 7 371 (13 ) 10 8 158 (5 ) 249 750 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 ALL balance at September 30, 2017 $ 3,878 $ 23 $ 1,758 $ 987 $ 248 $ 470 $ 1,836 $ 21 $ 144 $ 9,365 Charge-offs (95 ) — (15 ) (137 ) — (6 ) (1,087 ) (21 ) — (1,361 ) Recoveries 6 — 2 10 — 5 381 2 — 406 Provision (34 ) 10 1,076 359 21 (68 ) 774 19 (57 ) 2,100 ALL balance at March 31, 2018 $ 3,755 $ 33 $ 2,821 $ 1,219 $ 269 $ 401 $ 1,904 $ 21 $ 87 $ 10,510 ALL balance at September 30, 2016 $ 4,426 $ 13 $ 852 $ 882 $ 215 $ 455 $ 1,880 $ 25 $ 308 $ 9,056 Charge-offs (366 ) — (218 ) (20 ) — (6 ) (1,061 ) (4 ) — (1,675 ) Recoveries 6 — 10 — — 3 460 6 — 485 Provision 64 17 394 89 29 (7 ) 629 (3 ) 288 1,500 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 Acquired loans are recorded at fair value on their purchase date without a carryover of the related allowance for loan losses. The Company allocated increased provisions to commercial real estate loans due primarily to increased loan balances for the three month period ended March 31, 2018. The Company allocated increased provisions to commercial loans due primarily to increase loan balances and charge off activity for the three month period ended March 31, 2018. The Company allocated increased provisions to commercial real estate loans for the three month period ended March 31, 2017 due to charge off activity. The Company allocated increased provisions to auto loans for the three and six month periods ended March 31, 2018 and 2017 due to increased charge offs, net of recoveries. The following table summarizes the primary segments of the ALL, segregated into two categories, the amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment as of March 31, 2018 and September 30, 2017 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total Individually evaluated for impairment $ 160 $ — $ 12 $ — $ — $ 2 $ 130 $ — $ — $ 304 Collectively evaluated for impairment 3,595 33 2,809 1,219 269 399 1,774 21 87 10,206 ALL balance at March 31, 2018 $ 3,755 $ 33 $ 2,821 $ 1,219 $ 269 $ 401 $ 1,904 $ 21 $ 87 $ 10,510 Individually evaluated for impairment $ 154 $ — $ 19 $ — $ — $ — $ 172 $ — $ — $ 345 Collectively evaluated for impairment 3,724 23 1,739 987 248 470 1,664 21 144 9,020 ALL balance at September 30, 2017 $ 3,878 $ 23 $ 1,758 $ 987 $ 248 $ 470 $ 1,836 $ 21 $ 144 $ 9,365 The allowance for loan losses is based on estimates, and actual losses will vary from current estimates. Management believes that the granularity of the homogeneous pools and the related historical loss ratios and other qualitative factors, as well as the consistency in the application of assumptions, result in an ALL that is representative of the risk found in the components of the portfolio at any given date. Despite the above allocations, the allowance for loan losses is general in nature and is available to absorb losses from any loan segment. The following is a summary of troubled debt restructuring granted during the three and six months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential — — — Construction — — — Commercial 1 107 107 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans 1 15 15 Other — — — Total 2 $ 122 $ 122 For the Three Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 1 $ 135 $ 135 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 3 $ 291 $ 291 For the Six Months Ended March 31, 2018 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 2 $ 243 $ 235 Construction — — — Commercial 1 107 107 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans 1 15 15 Other — — — Total 4 $ 365 $ 357 For the Six Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 3 $ 379 $ 379 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 5 $ 535 $ 535 For the three months ended March 31, 2018, one loan for $107,000 was granted terms concessions and one loan for $15,000 was granted terms and rate concessions. Of the three new troubled debt restructurings granted for the three months ended March 31, 2017, one loan for $135,000 was granted terms concessions, one loan for $132,000 was granted terms and rate concessions, and one loan for $24,000 was granted interest rate concessions. For the six months ended March 31, 2018, three loans totaling $250,000 were granted terms and rate concessions and one loan for $107,000 was granted terms concessions. Of the five new troubled debt restructurings granted for the six months ended March 31, 2017, one loan totaling $135,000 was granted terms concessions, one loan totaling $24,000 was granted interest rate concessions, and three loans totaling $376,000 were granted terms and rate concessions. For the three months ended March 31, 2018, one loan totaling $72,000 defaulted on a restructuring agreement within one year of modification. For the six months ended March 31, 2018, two loan totaling $95,000 defaulted on a restructuring agreement within one year of modification. For the three months ended March 31, 2017 no loans defaulted on a restructuring agreement within one year of modification. For the six months ended March 31, 2017 one loan totaling $107,000 defaulted on a restricting agreement within one year of modification. Foreclosed assets acquired in settlement of loans are carried at fair value, less estimated costs to sell, and are included in the Consolidated Balance Sheet. As of March 31, 2018, included within the foreclosed assets is $790,000 of consumer residential mortgages that were foreclosed on or received via a deed in lieu of foreclosure transaction prior to the period end. As of March 31, 2018, the Company has initiated formal foreclosure proceedings on $2.6 million of consumer residential mortgages which have not yet been transferred into foreclosed assets.

Deposits

Deposits	6 Months Ended
	Mar. 31, 2018
Banking And Thrift [Abstract]
Deposits	7. Deposits Deposits consist of the following major classifications (in thousands): March 31, 2018 September 30, 2017 Non-interest bearing demand accounts $ 152,379 $ 160,125 Interest bearing demand accounts 164,611 208,369 Money market accounts 266,927 253,949 Savings and club accounts 143,715 141,521 Certificates of deposit 511,721 510,897 Total $ 1,239,353 $ 1,274,861

Net Periodic Benefit Cost-Defin

Net Periodic Benefit Cost-Defined Benefit Plan	6 Months Ended
	Mar. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Net Periodic Benefit Cost-Defined Benefit Plan	8 . Net Periodic Benefit Cost-Defined Benefit Plan For a detailed disclosure on the Bank’s pension and employee benefits plans, please refer to Note 12 of the Company’s Consolidated Financial Statements for the year ended September 30, 2017 included in the Company’s Annual Report on Form 10-K. The following table comprises the components of net periodic benefit cost for the three and six month periods ended March 31, 2018 and 2017 (in thousands): For the Three Months Ended March 31, For the Six Months Ended March 31, 2018 2017 2018 2017 Service Cost $ — $ 69 $ — $ 378 Interest Cost 175 208 349 443 Expected return on plan assets (299 ) (348 ) (597 ) (689 ) Amortization of unrecognized loss — 23 — 159 Net periodic benefit cost $ (124 ) $ (48 ) $ (248 ) $ 291 The Company’s board of directors adopted resolutions to freeze the status of the Defined Benefit Plan (“the plan”) effective February 28, 2017 (“the freeze date”). Accordingly, no additional participants will enter the plan after February 28, 2017; no additional years of service for benefit accrual purposes will be credited after the freeze date under the plan; and compensation earned by participants after the freeze date will not be taken into account under the plan. As a result of the freeze, the Company’s projected benefit obligation decreased by $7.1 million and there was a tax effected $4.7 million increase to accumulated other comprehensive income in the quarter ended March 31, 2017.

Equity Incentive Plan

Equity Incentive Plan	6 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plan	9 . Equity Incentive Plan The Company previously maintained the ESSA Bancorp, Inc. 2007 Equity Incentive Plan (the “Plan”). The Plan provided for a total of 2,377,326 shares of common stock for issuance upon the grant or exercise of awards. Of the shares that were available under the Plan, 1,698,090 were available to be issued in connection with the exercise of stock options and 679,236 were available to be issued as restricted stock. The Plan allowed for the granting of non-qualified stock options (“NSOs”), incentive stock options (“ISOs”), and restricted stock. Options granted under the plan were granted at no less than the fair value of the Company’s common stock on the date of the grant. As of the effective date of the 2016 Equity Incentive Plan (detailed below), no further grants will be made under the Plan and forfeitures of outstanding awards under the Plan will be added to the shares available under the 2016 Equity Incentive Plan. The Company replaced the 2007 Equity Incentive Plan with the ESSA Bancorp, Inc. 2016 Equity Incentive Plan (the “2016 Plan”) which was approved by shareholders on March 3, 2016. The 2016 Plan provides for a total of 250,000 shares of common stock for issuance upon the grant or exercise of awards. The 2016 Plan allows for the granting of restricted stock, restricted stock units, ISOs and NSOs. Certain officers, employees and outside directors were granted in aggregate 1,140,469 NSOs; 317,910 ISOs; and 590,320 shares of restricted stock on May 23, 2008. Certain officers were granted in aggregate 30,000 shares of restricted stock on April 1, 2013, 19,880 shares of restricted stock on July 22, 2014, 21,843 shares of restricted stock on May 20, 2015, 23,491 shares of restricted stock on March 4, 2016, 20,675 shares of restricted stock on December 13, 2016, 3,296 shares of restricted stock on March 29, 2017, 1,250 shares of restricted stock on October 23, 2017 and 24,278 of restricted stock on December 6, 2017. In accordance with generally accepted accounting principles, the Company expenses the fair value of all share-based compensation grants over the requisite service periods. The Company classifies share-based compensation for employees and outside directors within “Compensation and employee benefits” in the Consolidated Statement of Income to correspond with the same line item as compensation paid. Stock options vest over a five-year service period and expire ten years after the grant date. The Company recognized compensation expense for the fair values of these awards, which vested on a straight-line basis over the requisite service period of the awards. The 2013 restricted stock shares vested over an 18 month service period. The 2014 restricted shares vest over a 39 month service period. The 2015 restricted shares vest over a 40 month service period. The March 4, 2016 restricted shares vest over a 43 month service period. The December 13, 2016 restricted shares vest over a 46 month service period. The March 29, 2017 restricted shares vest over 42 months for 1,296 shares and over 18 months for 2,000 shares. The October 23, 2017 restricted shares vested over a 23 month service period. The December 6, 2017 restricted shares vest over a 46 month service period. The product of the number of shares granted and the grant date market price of the Company’s common stock determines the fair value of restricted shares under the Company’s restricted stock plan. For the six months ended March 31, 2018 and 2017, the Company recorded $184,000 and $145,000 of share-based compensation expense, respectively, comprised of restricted stock expense. Expected future compensation expense relating to the restricted shares issued in 2015, at March 31, 2018 is $41,000 over the remaining vesting period of 0.5 years. Expected future compensation expense relating to the restricted shares issued in March 2016, at March 31, 2018 is $128,000 over the remaining vesting period of 1.5 years. Expected future compensation expense relating to the restricted shares issued in December 2016, at March 31, 2018 is $223,000 over the remaining vesting period of 2.5 years. Expected future compensation expense relating to the restricted shares (1,296) issued in March 2017, at March 31, 2018 is $13,000 over the remaining vesting period of 2.5 years. Expected future compensation expense relating to the restricted shares (2,000) issued in March 2017, at March 31, 2018 is $10,000 over the remaining vesting period of 0.5 years. Expected future compensation expense relating to the restricted shares issued in October 2017, at March 31, 2018 is $15,000 over the remaining vesting period of 1.5 years. Expected future compensation expense relating to the restricted shares issued in December 2017, at March 31, 2018 is $352,000 over the remaining vesting period of 3.5 years. The following is a summary of the Company’s stock option activity and related information for its option grants for the six month period ended March 31, 2018. Number of Stock Options Weighted- average Exercise Price Weighted- average Remaining Contractual Term (in Aggregate Intrinsic Value (in thousands) Outstanding at September 30, 2017 294,646 $ 12.35 0.67 $ 987 Granted — — — — Exercised 196,848 12.35 0.17 — Forfeited — — — — Outstanding at March 31, 2018 97,798 $ 12.35 0.17 $ 227 Exercisable at March 31, 2018 97,798 $ 12.35 0.17 $ 227 The following is a summary of the status of the Company’s restricted stock as of March 31, 2018, and changes therein during the six month period then ended: Number of Restricted Weighted- average Grant Date Fair Value Nonvested at September 30, 2017 34,692 $ 14.89 Granted 25,528 15.86 Vested (1,000 ) — Forfeited (2,535 ) 14.79 Nonvested at March 31, 2018 56,685 $ 15.31

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurement	10. Fair Value Measurement The following disclosures show the hierarchal disclosure framework associated within the level of pricing observations utilized in measuring assets and liabilities at fair value. The definition of fair value maintains the exchange price notion in earlier definitions of fair value but focuses on the exit price of the asset or liability. The exit price is the price that would be received to sell the asset or paid to transfer the liability adjusted for certain inherent risks and restrictions. Expanded disclosures are also required about the use of fair value to measure assets and liabilities. The following tables present information about the Company’s securities, derivatives, other real estate owned, impaired loans and mortgage servicing rights measured at fair value as of March 31, 2018 and September 30, 2017 and indicates the fair value hierarchy of the valuation techniques utilized by the Bank to determine such fair value: Fair Value Measurement at March 31, 2018 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of March 31, 2018 Assets measured at fair value on a recurring basis: Investment securities available for sale: Mortgage backed securities $ — $ 246,708 $ — $ 246,708 Obligations of states and political subdivisions — 51,362 — 51,362 U.S. government agencies — 13,108 — 13,108 Corporate obligations — 37,221 7,767 44,988 Other debt securities — 21,184 — 21,184 Equity securities-financial services 25 — — 25 Total Securities $ 25 $ 369,583 $ 7,767 $ 377,375 Derivatives and hedging activities: $ — $ 2,312 $ — $ 2,312 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 1,279 $ 1,279 Impaired loans $ — $ — $ 13,614 $ 13,614 Mortgage servicing rights $ — $ — $ 220 $ 220 Fair Value Measurement at September 30, 2017 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of September 30, 2017 Assets measured at fair value on a recurring basis: Investment securities available for sale: Mortgage backed securities $ — $ 233,823 $ — $ 233,823 Obligations of states and political subdivisions — 65,358 — 65,358 U.S. government agencies — 18,671 — 18,671 Corporate obligations — 41,518 7,224 48,742 Other debt securities — 23,833 — 23,833 Equity securities-financial services 25 — — 25 Total Securities $ 25 $ 383,203 $ 7,224 $ 390,452 Derivatives and hedging activities $ — $ 1,215 $ — $ 1,215 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 1,424 $ 1,424 Impaired loans $ — $ — $ 15,231 $ 15,231 Mortgage Servicing rights $ — $ — $ 232 $ 232 The following tables present a summary of changes in the fair value of the Company’s Level III investments for the three and six month periods ended March 31, 2018 and 2017 (in thousands). Fair Value Measurement Using Significant Unobservable Inputs (Level III) Three Months Ended March 31, 2018 March 31, 2017 Beginning balance $ 7,826 $ 8,238 Purchases, sales, issuances, settlements, net — 756 Total unrealized gain (loss): Included in earnings — — Included in other comprehensive loss (59 ) (259 ) Transfers in and/or out of Level III — — $ 7,767 $ 8,735 Fair Value Measurement Using Significant Unobservable Inputs (Level III) Six Months Ended March 31, 2018 March 31, 2017 Beginning balance $ 7,224 $ 7,485 Purchases, sales, issuances, settlements, net 500 756 Total unrealized gain (loss): Included in earnings — — Included in other comprehensive income 43 494 Transfers in and/or out of Level III — — $ 7,767 $ 8,735 Each financial asset and liability is identified as having been valued according to a specified level of input, 1, 2 or 3. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Fair values determined by Level 2 inputs utilize inputs other than quoted prices included in Level 1 that are observable for the asset, either directly or indirectly. Level 2 inputs include quoted prices for similar assets in active markets, and inputs other than quoted prices that are observable for the asset or liability. Level 3 inputs are unobservable inputs for the asset, and include situations where there is little, if any, market activity for the asset or liability. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy, within which the fair value measurement in its entirety falls, has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset. The measurement of fair value should be consistent with one of the following valuation techniques: market approach, income approach, and/or cost approach. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities (including a business). For example, valuation techniques consistent with the market approach often use market multiples derived from a set of comparables. Multiples might lie in ranges with a different multiple for each comparable. The selection of where within the range the appropriate multiple falls requires judgment, considering factors specific to the measurement (qualitative and quantitative). Valuation techniques consistent with the market approach include matrix pricing. Matrix pricing is a mathematical technique used principally to value debt securities without relying exclusively on quoted prices for the specific securities, but rather by relying on a security’s relationship to other benchmark quoted securities. Most of the securities classified as available for sale are reported at fair value utilizing Level 2 inputs. For these securities, the Company obtains fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quoted market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Securities reported at fair value utilizing Level 1 inputs are limited to actively traded equity securities whose market price is readily available from the New York Stock Exchange or the NASDAQ exchange. A few securities are valued using Level 3 inputs, all of these are classified as available for sale and are reported at fair value using Level 3 inputs. Mortgage servicing rights are also valued by an independent pricing service. Foreclosed real estate is measured at fair value, less cost to sell at the date of foreclosure, valuations are periodically performed by management and the assets are carried at the lower of carrying amount or fair value, less cost to sell. Income and expenses from operations and changes in valuation allowance are included in the net expenses from foreclosed real estate. Impaired loans are reported at fair value utilizing level three inputs. For these loans, a review of the collateral is conducted and an appropriate allowance for loan losses is allocated to the loan. At March 31, 2018, 140 impaired loans with a carrying value of $13.9 million were reduced by specific valuation allowance totaling $304,000 resulting in a net fair value of $13.6 million based on Level 3 inputs. At September 30, 2017, 164 impaired loans with a carrying value of $15.6 million were reduced by a specific valuation totaling $345,000 resulting in a net fair value of $15.2 million based on Level 3 inputs. The following tables present additional quantitative information about assets measured at fair value on a nonrecurring basis and for which the Company has utilized Level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range March 31, 2018 Impaired loans $ 13,614 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 35% (25.3%) Foreclosed real estate owned 1,279 Appraisal of collateral (1), (3) Appraisal adjustments (2) 20% to 46% (23.2%) Mortgage servicing rights 220 Discounted cash flow Discount rate 11.0% (11.0%) Prepayment speeds 7% to 28% (12.2%) Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range September 30, 2017 Impaired loans $ 15,231 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 57% (24.0%) Foreclosed real estate owned 1,424 Appraisal of collateral (1), (3) Appraisal adjustments (2) 20% to 46% (22.0%) Mortgage servicing rights 232 Discounted cash flow Discount rate 11.0% (11.0%) Prepayment speeds 11% to 30% (15.9%) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range of liquidation expenses and other appraisal adjustments are presented as a percent of the appraisal. The fair values presented represent the Company’s best estimate of fair value using the methodologies discussed below. Disclosures about Fair Value of Financial Instruments The fair values presented represent the Company’s best estimate of fair value using the methodologies discussed below (in thousands). March 31, 2018 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 34,804 $ 34,804 $ — $ — $ 34,804 Certificates of deposit 500 — — 501 501 Investment and mortgage backed securities available for sale 377,375 25 369,583 7,767 377,375 Loans receivable, net 1,291,262 — — 1,265,713 1,265,713 Accrued interest receivable 6,279 6,279 — — 6,279 Regulatory stock 17,234 17,234 — — 17,234 Mortgage servicing rights 220 — — 220 220 Derivatives 2,312 — 2,312 — 2,312 Bank owned life insurance 38,130 38,130 — — 38,130 Financial liabilities: Deposits $ 1,239,353 $ 727,632 $ — $ 508,654 $ 1,236,286 Short-term borrowings 241,345 241,345 — — 241,345 Other borrowings 139,434 — — 138,434 138,434 Advances by borrowers for taxes and insurance 12,188 12,188 — — 12,188 Accrued interest payable 1,077 1,077 — — 1,077 September 30, 2017 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 41,683 $ 41,683 $ — $ — $ 41,683 Certificates of deposit 500 — — 505 505 Investment and mortgage backed securities available for sale 390,452 25 383,203 7,224 390,452 Loans receivable, net 1,236,681 — — 1,235,368 1,235,368 Accrued interest receivable 6,149 6,149 — — 6,149 Regulatory stock 13,832 13,832 — — 13,832 Mortgage servicing rights 232 — — 232 232 Derivatives 1,215 — 1,215 — 1,215 Bank owned life insurance 37,626 37,626 — — 37,626 Financial liabilities: Deposits $ 1,274,861 $ 763,964 $ — $ 511,392 $ 1,275,356 Short-term borrowings 137,446 137,446 — — 137,446 Other borrowings 174,168 — — 174,107 174,107 Advances by borrowers for taxes and insurance 5,163 5,163 — — 5,163 Accrued interest payable 1,043 1,043 — — 1,043 Financial instruments are defined as cash, evidence of an ownership interest in an entity, or a contract which creates an obligation or right to receive or deliver cash or another financial instrument from/to a second entity on potentially favorable or unfavorable terms. Fair value is defined as the amount at which a financial instrument could be exchanged in a current transaction between willing parties other than in a forced or liquidation sale. If a quoted market price is available for a financial instrument, the fair value would be calculated based upon the market price per trading unit of the instrument. If no readily available market exists, the fair value for financial instruments should be based upon management’s judgment regarding current economic conditions, interest rate risk, expected cash flows, future estimated losses, and other factors as determined through various option pricing formulas or simulation modeling. As many of these assumptions result from judgments made by management based upon estimates which are inherently uncertain, the resulting values may not be indicative of the amount realizable in the sale of a particular financial instrument. In addition, changes in the assumptions on which the values are based may have a significant impact on the resulting estimated values. As certain assets and liabilities, such as deferred tax assets, premises and equipment, and many other operational elements of the Bank, are not considered financial instruments but have value, this fair value of financial instruments would not represent the full market value of the Company. The Company employed simulation modeling in determining the fair value of financial instruments for which quoted market prices were not available based upon the following assumptions: Cash and Cash Equivalents, Accrued Interest Receivable, Short-Term Borrowings, Advances by Borrowers for Taxes and Insurance, and Accrued Interest Payable The fair value approximates the current book value. Bank-Owned Life Insurance The fair value is equal to the cash surrender value of the Bank-owned life insurance. Investment and Mortgage-Backed Securities Available for Sale and Regulatory Stock The fair value of investment and mortgage-backed securities available for sale is equal to the available quoted market price. If no quoted market price is available, fair value is estimated using the quoted market price for similar securities. Since the Regulatory stock is not actively traded on a secondary market and held exclusively by member financial institutions, the fair market value approximates the carrying amount. For certain securities which are not traded in active markets or are subject to transfer restrictions, valuations are adjusted to reflect illiquidity and/or non-transferability, and such adjustments are generally based on available market evidence (Level 3). In the absence of such evidence, management’s best estimate is used. Management’s best estimate consists of both internal and external support on certain Level 3 investments. Internal cash flow models using a present value formula that includes assumptions market participants would use along with indicative exit pricing obtained from broker/dealers (where available) are used to support fair values of certain Level 3 investments, if applicable. Loans Receivable, Net The fair values of loans are estimated using discounted cash flow analyses, using market rates at the balance sheet date that reflect the credit and interest rate-risk inherent in the loans. Projected future cash flows are calculated based upon contractual maturity or call dates, projected repayments and prepayments of principal. Generally, for variable rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values. Mortgage Servicing Rights The Company utilizes a third party provider to estimate the fair value of certain loan servicing rights. Fair value for the purpose of this measurement is defined as the amount at which the asset could be exchanged in a current transaction between willing parties, other than in a forced liquidation. Derivatives Fair values of interest rate cap and interest rate swap contracts are based on dealer quotes. Deposits (including Certificates of Deposit) The fair values disclosed for demand, savings, and money market deposit accounts are valued at the amount payable on demand as of quarter-end. Fair values for time deposits are estimated using a discounted cash flow calculation that applies contractual costs currently being offered in the existing portfolio to current market rates being offered for deposits of similar remaining maturities. Other Borrowings Fair values for other borrowings are estimated using a discounted cash flow calculation that applies contractual costs currently being offered in the existing portfolio to current market rates being offered for other borrowings of similar remaining maturities. Commitments to Extend Credit These financial instruments are generally not subject to sale, and fair values are not readily available. The carrying value, represented by the net deferred fee arising from the unrecognized commitment, and the fair value, determined by discounting the remaining contractual fee over the term of the commitment using fees currently charged to enter into similar agreements with similar credit risk, are not considered material for disclosure.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Loss	11. Accumulated Other Comprehensive Loss The activity in accumulated other comprehensive loss for the three and six months period ended March 31, 2018 and 2017 is as follows (in thousands): Accumulated Other Comprehensive Loss Defined Benefit Pension Plan Unrealized (Losses) on Securities Available for Sale Derivatives Total Balance at December 31, 2017 $ (628 ) $ (2,215 ) $ 1,087 $ (1,756 ) Other comprehensive income before reclassifications — (5,100 ) 587 (4,513 ) Amounts reclassified from accumulated other comprehensive loss — (57 ) (63 ) (120 ) Reclassification of certain income tax effects from accumulated other comprehensive income (124 ) (436 ) 214 (346 ) Period change (124 ) (5,593 ) 738 (4,979 ) Balance at March 31, 2018 $ (752 ) $ (7,808 ) $ 1,825 $ (6,735 ) Balance at December 31, 2016 $ (5,993 ) $ (2,801 ) $ 899 $ (7,895 ) Other comprehensive income before reclassifications 4,714 781 25 5,520 Amounts reclassified from accumulated other comprehensive loss, net of tax 13 — (2 ) 11 Period change 4,727 781 23 5,531 Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 ) Accumulated Other Comprehensive Income/(Loss) Defined Benefit Pension Plan Unrealized Gains (Losses) on Securities Available for Sale Derivatives Total Balance at September 30, 2017 $ (628 ) $ (927 ) $ 801 $ (754 ) Other comprehensive income (loss) before reclassifications — (6,388 ) 888 (5,500 ) Amounts reclassified from accumulated other comprehensive loss, net of tax — (57 ) (78 ) (135 ) Reclassification of certain income tax effects from accumulated other comprehensive income (124 ) (436 ) 214 (346 ) Period change (124 ) (6,881 ) 1,024 (5,635 ) Balance at March 31, 2018 $ (752 ) $ (7,808 ) $ 1,825 $ (6,735 ) Balance at September 30, 2016 $ (6,083 ) $ 3,952 $ 299 $ (1,832 ) Other comprehensive income before reclassifications 4,714 (5,972 ) 619 (639 ) Amounts reclassified from accumulated other comprehensive loss, net of tax 103 — 4 107 Period change 4,817 (5,972 ) 623 (532 ) Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 ) The following table presents significant amounts reclassified out of each component of accumulated other comprehensive loss for the three and six month periods ended March 31, 2018 and 2017 (in thousands): Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss for the Three Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2018 2017 Securities available for sale Net securities gains reclassified into earnings 75 — Gains on sale of investments, net Related income tax expense (18 ) — Income taxes Net effect on accumulated other comprehensive loss for the period 57 — Net of tax Defined benefit pension plan: Amortization of net (loss) gain and prior service costs — (23 ) Compensation and employee Related income tax expense — 10 Income taxes Net effect on accumulated other comprehensive loss for the period — (13 ) Net of tax Derivatives and hedging activities: Interest expense, effective portion 76 5 Interest expense Related income tax expense (13 ) (3 ) Income taxes Net effect on accumulated other comprehesive loss for the period 63 2 Net of tax Total reclassification for the period $ 120 $ (11 ) Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss For the Six Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2018 2017 Securities available for sale: Net securities gains reclassified into earnings 75 — Gain on sale of investments, net Related income tax expense (18 ) — Income taxes Net effect on accumulated other comprehensive loss for the period 57 — Net of tax Defined benefit pension plan: Amoritization of net (loss) gain and prior services costs — (159 ) Compensation and employee benefits Related income tax expense — 56 Income taxes Net effect on accumulated other comprehensive loss for the period — (103 ) Net of tax Derivative and Hedging Activities: Interest expense, effective portion 99 (6 ) Interest expense Related income tax expense (21 ) 2 Income taxes Net effect on accumulated other comprehensive loss for the period 78 (4 ) Net of tax Total reclassification for the period $ 135 $ (107 )

Derivative and Hedging Activiti

Derivative and Hedging Activities	6 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	12. Derivatives and Hedging Activities Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and through the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to certain variable rate borrowings. Fair Values of Derivative Instruments on the Consolidated Balance Sheet The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheet as of March 31, 2018 and September 30, 2017 (in thousands). Fair Values of Derivative Instruments Asset Derivatives As of March 31, 2018 As of September 30, 2017 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest Rate Products Other Assets $ 2,312 Other Assets $ 1,215 Cash Flow Hedges of Interest Rate Risk The Company’s objectives in using interest rate derivatives are to add stability to interest income and expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company has entered into interest rate swaps as part of its interest rate risk management strategy. These interest rate swaps are designated as cash flow hedges and involve the receipt of variable rate amounts from a counterparty in exchange for the Company making fixed payments. As of March 31, 2018, the Company had three interest rate swaps with a notional principal amount of $75.0 million associated with the Company’s cash outflows associated with various FHLB advances. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (outside of earnings), net of tax, and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion of changes in the fair value of the derivative is recognized directly in earnings. The Company assesses the effectiveness of each hedging relationship by comparing the changes in cash flows of the derivative hedging instrument with the changes in cash flows of the designated hedged transactions. The Company did not recognize any hedge ineffectiveness in earnings during the period ended March 31, 2018. Amounts reported in accumulated other comprehensive loss related to derivatives that will be reclassified to interest income/expense as interest payments are made/received on the Company’s variable-rate assets/liabilities. During the three months ended March 31, 2018, the Company had $76,000 of gains reclassified to interest expense. During the six months ended March 31, 2018, the Company had $99,000 of gains reclassified to interest expense. During the next twelve months, the Company estimates that $0 will be reclassified as a decrease in interest expense. The tables below present the pre-tax net gains (losses) of the Company’s cash flow hedges for the three month periods ended March 31, 2018 and 2017, respectively, and where they were recorded in the Consolidated Statement of Income, (in thousands). Derivatives in Cash Flow Hedging Relationships Loss Recognized in OCI on Derivative (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Three Months Ended March 31, 2018 2017 2018 2017 2018 2017 Interest Rate Products $ 738 $ 40 Interest expense $ 76 $ 5 Other non-interest income $ — $ — Ending balance of OCI Total $ 738 $ 40 $ 76 $ 5 $ — $ — Derivatives in Cash Flow Hedging Relationships Gain Recognized in OCI on Derivative (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (Loss)Reclassified from Accumulated OCI into Income (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Six Months Ended March 31, 2018 2017 2018 2017 2018 2017 Interest Rate Products $ 1,195 $ 1,092 Interest expense $ 99 $ (6 ) Other non-interest income $ — $ — Ending balance of OCI Total $ 1,195 $ 1,092 $ 99 $ (6 ) $ — $ — Credit-risk-related Contingent Features The Company has agreements with its derivative counterparties that contain a provision where if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. The Company also has agreements with certain of its derivative counterparties that contain a provision where if the Company fails to maintain its status as a well / adequately capitalized institution, then the counterparty could terminate the derivative positions and the Company would be required to settle its obligations under the agreements. As of March 31, 2018 the Company had no derivatives in a net liability position and was not required to post collateral against its obligations under these agreements. If the Company had breached any of these provisions at March 31, 2018, it could have been required to settle its obligations under the agreements at the termination value.

Contingent Liabilities

Contingent Liabilities	6 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Contingent Liabilities	13. Contingent Liabilities Legal Proceedings The Company and its subsidiaries are subject to various legal actions arising in the normal course of business. In the opinion of Management, the resolution of these legal actions is not expected to have a material adverse effect on the Company’s results of operations. The Bank was named as the defendant in an action commenced on September 13, 2016 by one plaintiff. The plaintiff alleges that the Bank repossessed motor vehicles, sold the vehicles and sought to collect deficiency balances in a manner that did not comply with the notice requirements of the Pennsylvania Uniform Commercial Code (“UCC”). The plaintiff seeks to pursue the action as a class action on behalf of the named plaintiff and other similarly situated plaintiffs who had their automobiles repossessed and seek to recover damages under the UCC. The Bank denies the plaintiff’s allegations. The parties attended a mediation in October, 2017 where they reached an agreement to resolve the claims asserted against the Bank on a class wide basis. The terms of the settlement calls for the Bank to make a payment of $1,325,000 to the plaintiffs. The Bank’s insurance carrier will cover the payment made by the Bank in excess of a $125,000 retention. The court has entered an order preliminarily approving the settlement. The court has set a final approval hearing for May 2018. The Bank was named as a defendant in an action commenced on December 8, 2016 by one plaintiff who will also seek to pursue this action as a class action on behalf of the entire class of people similarly situated. The plaintiff alleges that a bank previously acquired by ESSA Bancorp, Inc., in the process of making loans, received unearned fees and kickbacks in violation of the Real Estate Settlement Procedures Act. In an order dated January 29, 2018, the court granted the Bank’s motion to dismiss the case. The plaintiff has appealed the courts ruling. Preliminary arguments are due in June, 2018 to the extent that this litigation could result in exposure to the bank. The amount is not currently estimable.

Income Taxes

Income Taxes	6 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The reconciliation of the federal statutory rate and the Company’s effective income tax rate is as follows (in thousands): For the Three Months Ended March 31, 2018 2017 Amount % of Pretax Income Amount % of Pretax Income Provision at statutory rate $ 676 24.2 % $ 622 34.0 % Income from bank-owned life insurance (60 ) (2.2 ) (86 ) (4.7 ) Tax-exempt income (134 ) (4.8 ) (216 ) (11.8 ) Low-income housing credits 52 1.9 (74 ) (4.0 ) Other, net (5 ) (0.2 ) (43 ) (2.3 ) Actual tax expense and effective rate $ 529 18.9 % $ 203 11.2 % For the Six Months Ended March 31, 2018 2017 Amount % of Pretax Income Amount % of Pretax Income Provision at statutory rate $ 1,271 24.2 % $ 1,417 34.0 % Income from bank-owned life insurance (122 ) (2.3 ) (176 ) (4.2 ) Tax-exempt income (269 ) (5.1 ) (432 ) (10.4 ) Low-income housing credits (43 ) (0.8 ) (123 ) (2.9 ) Tax rate change 3,780 72.1 — — Other, net 5 (0.1 ) (83 ) (2.0 ) Actual tax expense and effective rate $ 4,622 88.1 % $ 603 14.5 % On December 22, 2017, the U.S. Government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). The Tax Act amends the Internal Revenue Code to reduce tax rates and modify policies, credits, and deductions for individuals and businesses. For businesses, the Tax Act reduces the corporate federal tax rate from a maximum of 35% to a flat 21% rate. The corporate tax rate reduction was effective January 1, 2018. Because the Company has a fiscal year end of September 30, the reduced corporate tax rate will result in the application of a blended federal statutory tax rate for its fiscal year 2018 and then a flat 21% thereafter. As a result, the carrying value of net deferred tax assets was reduced in December 2017, which increased income tax expense by $3.8 million. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. These calculations are based on many complex factors including estimates of the timing of reversals of temporary differences, the interpretation of federal income tax laws, and a determination of the differences between the tax and the financial reporting basis of assets and liabilities. Actual results could differ significantly from the estimates and interpretations used in determining the current and deferred income tax assets and liabilities. Under GAAP, a valuation allowance is required to be recognized if it is “more likely than not” that a portion of the deferred tax asset will not be realized. Our policy is to evaluate our deferred tax assets on a quarterly basis and record a valuation allowance for our deferred tax asset if we do not have sufficient positive evidence indicating that it is more likely than not that some or all of the deferred tax asset will be realized. Each quarter, we consider positive evidence, which may include taxes paid in carryback years, reversing timing differences, available tax planning strategies, and projected taxable income and weigh it against negative evidence, which may include cumulative losses in the most recent three year period and uncertainty regarding short-term future earnings, among other items. At March 31, 2018, management determined that no valuation allowance on the deferred tax asset was required. This determination was based on sufficient positive evidence associated with our profitability, demonstrated through consecutive earnings over the recent three year period, and our projections for future taxable income.

Recent Accounting Pronounceme23

Recent Accounting Pronouncements (Policies)	6 Months Ended
	Mar. 31, 2018
Accounting Changes And Error Corrections [Abstract]
Revenue from Contracts with Customers	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers Topic 606 In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606). Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Deferral of the Effective Date In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606) Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date
Financial Instruments	In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments
Lease	In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In January 2018, the FASB issued ASU 2018-01, Leases (Topic 842)
Statement of Cash Flows	In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments
Business Combinations	In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business
Goodwill Impairment	In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment
Other Income	In February 2017, the FASB issued ASU 2017-05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20).
Compensation	In March 2017, the FASB issued ASU 2017-07, Compensation—Retirement Benefits (Topic 715) In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation (Topic 718) .
Receivables	In March 2017, the FASB issued ASU 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20). The amendments in this Update shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public business entities, the amendments in this Update are effective for fiscal years, and interim periods within those fiscal years, beg For all other entities, the amendments are effective for fiscal years beginning after December 15, 2019, and interim periods within fiscal years beginning after December 15, 2020. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity should apply the amendments in this Update on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Additionally, in the period of adoption, an entity should provide disclosures about a change in accounting principle. This Update is not expected to have a significant impact on the Company’s financial statements.
Earnings Per Share	In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivative and Hedging (Topic 815) Debt—Debt with Conversion and Other Options
Derivatives and Hedging	In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 850)
Income Statement	In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220)
Technical Corrections and Improvements to Financial Instruments	In February 2018, the FASB issued ASU 2018-03, Technical Corrections and Improvements to Financial Instruments—Overall (Subtopic 825-10) Fair Value Measurement Derivatives and Hedging—Embedded Derivatives Financial Instruments—Overall Financial Services— Insurance

Earnings per Share (Tables)

Earnings per Share (Tables)	6 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Composition of the Weighted-Average Common Shares (Denominator) Used in the Basic and Diluted Earnings Per Share Computation	The following table sets forth the composition of the weighted-average common shares (denominator) used in the basic and diluted earnings per share computation for the three and six month periods ended March 31, 2018 and 2017. Three Months Ended Six Months Ended March 31, March 31, March 31, March 31, 2018 2017 2018 2017 Weighted-average common shares outstanding 18,133,095 18,133,095 18,133,095 18,133,095 Average treasury stock shares (6,459,392 ) (6,618,067 ) (6,490,961 ) (6,670,049 ) Average unearned ESOP shares (843,010 ) (888,285 ) (848,729 ) (894,004 ) Average unearned non-vested shares (34,340 ) (33,746 ) (44,318 ) (42,958 ) Weighted average common shares and common stock equivalents used to calculate basic earnings per share 10,796,353 10,592,997 10,749,087 10,526,084 Additional common stock equivalents (non-vested stock) used to calculate diluted earnings per share 347 1,646 143 — Additional common stock equivalents (stock options) used to calculate diluted earnings per share 25,409 97,317 31,149 91,157 Weighted average common shares and common stock equivalents used to calculate diluted earnings per share 10,822,109 10,691,960 10,780,379 10,617,241

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Mar. 31, 2018
Investments Debt And Equity Securities [Abstract]
Summary of Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Investment Securities Available for Sale	The amortized cost, gross unrealized gains and losses, and fair value of investment securities available for sale are summarized as follows (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 136,157 $ 15 $ (3,880 ) $ 132,292 Freddie Mac 97,336 5 (3,113 ) 94,228 Governmental National Mortgage Association Securities 20,845 — (657 ) 20,188 Total mortgage-backed securities 254,338 20 (7,650 ) 246,708 Obligations of states and political subdivisions 52,046 621 (1,305 ) 51,362 U.S. government agency securities 13,191 26 (109 ) 13,108 Corporate obligations 45,748 242 (1,002 ) 44,988 Other debt securities 21,910 3 (729 ) 21,184 Total debt securities 387,233 912 (10,795 ) 377,350 Equity securities - financial services 25 — — 25 Total $ 387,258 $ 912 $ (10,795 ) $ 377,375 September 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available for Sale Fannie Mae $ 119,333 $ 207 $ (1,203 ) $ 118,337 Freddie Mac 98,668 177 (808 ) 98,037 Governmental National Mortgage Association 17,609 43 (203 ) 17,449 Total mortgage-backed securities 235,610 427 (2,214 ) 233,823 Obligations of states and political subdivisions 64,382 1,522 (546 ) 65,358 U.S. government agency securities 18,615 61 (5 ) 18,671 Corporate obligations 49,025 335 (618 ) 48,742 Other debt securities 24,200 47 (414 ) 23,833 Total debt securities 391,832 2,392 (3,797 ) 390,427 Equity securities - financial services 25 — — 25 Total $ 391,857 $ 2,392 $ (3,797 ) $ 390,452
Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	The amortized cost and fair value of debt securities at March 31, 2018, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties (in thousands): Available For Sale Amortized Cost Fair Value Due in one year or less $ 1,748 $ 1,750 Due after one year through five years 34,694 34,396 Due after five years through ten years 100,607 98,495 Due after ten years 250,184 242,709 Total $ 387,233 $ 377,350
Schedule of Gross Unrealized Losses and Fair Value	The following tables show the Company’s gross unrealized losses and fair value, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position (dollars in thousands): March 31, 2018 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 90 $ 84,342 $ (1,691 ) $ 45,723 $ (2,189 ) $ 130,065 $ (3,880 ) Freddie Mac 68 61,564 (1,553 ) 31,808 (1,560 ) 93,372 (3,113 ) Governmental National Mortgage Association 17 13,429 (309 ) 6,759 (348 ) 20,188 (657 ) Obligations of states and political subdivisions 28 11,431 (217 ) 19,765 (1,088 ) 31,196 (1,305 ) U.S. government agency securities 4 8,718 (109 ) — — 8,718 (109 ) Corporate obligations 29 20,338 (350 ) 9,465 (652 ) 29,803 (1,002 ) Other debt securities 19 2,085 (34 ) 17,858 (695 ) 19,943 (729 ) Total 255 $ 201,907 $ (4,263 ) $ 131,378 $ (6,532 ) $ 333,285 $ (10,795 ) September 30, 2017 Number of Securities Less than Twelve Months Twelve Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fannie Mae 55 $ 61,852 $ (558 ) $ 20,679 $ (645 ) $ 82,531 $ (1,203 ) Freddie Mac 39 38,913 (354 ) 16,427 (454 ) 55,340 (808 ) Governmental National Mortgage Association 11 6,669 (41 ) 6,903 (162 ) 13,572 (203 ) Obligations of states and political subdivisions 25 10,944 (59 ) 17,425 (487 ) 28,369 (546 ) U.S. government agency securities 3 8,995 (5 ) — — 8,995 (5 ) Corporate obligations 22 15,119 (104 ) 8,032 (514 ) 23,151 (618 ) Other debt securities 19 7,141 (104 ) 13,806 (310 ) 20,947 (414 ) Total 174 $ 149,633 $ (1,225 ) $ 83,272 $ (2,572 ) $ 232,905 $ (3,797 )

Loans Receivable, Net and All26

Loans Receivable, Net and Allowance for Loan Losses (Tables)	6 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Summary of Loans Receivable	Loans receivable consist of the following (in thousands): March 31, 2018 September 30, 2017 Real estate loans: Residential $ 583,926 $ 586,708 Construction 4,072 3,097 Commercial 383,561 318,323 Commercial 49,273 44,129 Obligations of states and political subdivisions 55,615 58,079 Home equity loans and lines of credit 44,247 46,219 Auto Loans 178,420 186,646 Other 2,658 2,845 1,301,772 1,246,046 Less allowance for loan losses 10,510 9,365 Net loans $ 1,291,262 $ 1,236,681
Changes in Accretable Yield for Purchased Credit-Impaired Loans	Changes in the accretable yield for purchased credit-impaired loans were as follows, since acquisition, for the three and six months ended March 31, 2018 and 2017 (in thousands): For the Three Months Ended March 31, 2018 2017 Balance at beginning of period $ 755 $ 453 Reclassification, new additions and other 85 82 Accretion (266 ) (75 ) Balance at end of period $ 574 $ 460
Summary of Additional Information Regarding Loans Acquired and Accounted	The following table presents additional information regarding loans acquired and accounted for in accordance with ASC 310-30 (in thousands): March 31, 2018 September 30, 2017 Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Acquired Loans with Specific Evidence or Deterioration in Credit Quality (ASC 310-30) Outstanding balance $ 4,852 $ 5,490 Carrying amount $ 4,480 $ 4,388
Schedule of Loans Evaluated for Impairment	The following tables show the amount of loans in each category that were individually and collectively evaluated for impairment at the dates indicated (in thousands): Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment March 31, 2018 Real estate loans: Residential $ 583,926 $ 5,190 $ — $ 578,736 Construction 4,072 — — 4,072 Commercial 383,561 6,803 3,900 372,858 Commercial 49,273 1,142 252 47,879 Obligations of states and political subdivisions 55,615 — — 55,615 Home equity loans and lines of credit 44,247 198 328 43,721 Auto loans 178,420 558 — 177,862 Other 2,658 27 — 2,631 Total $ 1,301,772 $ 13,918 $ 4,480 $ 1,283,374 Total Loans Individually Evaluated for Impairment Loans Acquired with Deteriorated Credit Quality Collectively Evaluated for Impairment September 30, 2017 Real estate loans: Residential $ 586,708 $ 6,202 $ — $ 580,506 Construction 3,097 — — 3,097 Commercial 318,323 7,211 3,775 307,337 Commercial 44,129 1,385 283 42,461 Obligations of states and political sub divisions 58,079 — — 58,079 Home equity loans and lines of credit 46,219 176 330 45,713 Auto loans 186,646 572 — 186,074 Other 2,845 30 — 2,815 Total $ 1,246,046 $ 15,576 $ 4,388 $ 1,226,082
Schedule of Investment and Unpaid Principal Balances for Impaired Loans	The following tables include the recorded investment and unpaid principal balances for impaired loans with the associated allowance amount at the dates indicated, if applicable (in thousands): Recorded Investment Unpaid Principal Balance Associated Allowance March 31, 2018 With no specific allowance recorded: Real estate loans Residential $ 3,879 $ 5,193 $ — Construction — — — Commercial 6,785 8,729 — Commercial 1,142 1,397 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 172 186 — Auto loans 214 420 — Other 27 34 — Total 12,219 15,959 — With an allowance recorded: Real estate loans Residential 1,311 1,561 160 Construction — — — Commercial 18 22 12 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 26 27 2 Auto loans 344 355 130 Other — — — Total 1,699 1,965 304 Total: Real estate loans Residential 5,190 6,754 160 Construction — — — Commercial 6,803 8,751 12 Commercial 1,142 1,397 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 198 213 2 Auto loans 558 775 130 Other 27 34 — Total Impaired Loans $ 13,918 $ 17,924 $ 304 Recorded Investment Unpaid Principal Balance Associated Allowance September 30, 2017 With no specific allowance recorded: Real Estate Loans Residential $ 4,392 $ 5,730 $ — Construction — — — Commercial 7,191 9,396 — Commercial 1,385 1,575 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 176 258 — Auto Loans 123 237 — Other 30 36 — Total 13,297 17,232 — With an allowance recorded: Real Estate Loans Residential 1,810 2,264 154 Construction — — — Commercial 20 1,193 19 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto Loans 449 468 172 Other — — — Total 2,279 3,925 345 Total: Real Estate Loans Residential 6,202 7,994 154 Construction — — — Commercial 7,211 10,589 19 Commercial 1,385 1,575 — Obligations of states and political subdivisions — — — Home equity loans and lines of credit 176 258 — Auto Loans 572 705 172 Other 30 36 — Total Impaired Loans $ 15,576 $ 21,157 $ 345 The following tables represent the average recorded investments in the impaired loans and the related amount of interest recognized during the time within the period that the impaired loans were impaired (in thousands): For the Three Months Ended March 31, 2018 2017 2018 2017 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 4,180 $ 5,573 $ 6 $ 9 Construction — — — — Commercial 6,789 9,218 69 67 Commercial 1,178 1,637 24 29 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 203 202 — — Auto loans 208 102 — — Other 28 8 — — Total 12,586 16,740 99 105 With an allowance recorded: Real estate loans Residential 1,256 1,985 — — Construction — — — — Commercial 19 341 — — Commercial — 100 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 12 5 — — Auto loans 231 291 — 2 Other — — — — Total 1,518 2,722 — 2 Total: Real estate loans Residential 5,436 7,558 6 9 Construction — — — — Commercial 6,808 9,559 69 67 Commercial 1,178 1,737 24 29 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 215 207 — — Auto loans 439 393 — 2 Other 28 8 — — Total Impaired Loans $ 14,104 $ 19,462 $ 99 $ 107 For the Six Months Ended March 31, 2018 2017 2018 2017 Average Recorded Investment Average Recorded Investment Interest Income Recognized Interest Income Recognized With no specific allowance recorded: Real estate loans Residential $ 4,305 $ 6,049 $ 16 $ 21 Construction — — — — Commercial 6,897 9,890 141 172 Commercial 1,233 1,665 51 62 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 205 260 1 — Auto loans 172 119 1 — Other 29 8 — — Total 12,841 17,991 210 255 With an allowance recorded: Real estate loans Residential 1,392 2,025 — — Construction — — — — Commercial 19 345 — — Commercial — 59 — — Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 7 4 — — Auto loans 247 253 — 6 Other — — — — Total 1,665 2,686 — 6 Total: Real estate loans Residential 5,697 8,074 16 21 Construction — — — — Commercial 6,916 10,235 141 172 Commercial 1,233 1,724 51 62 Obligations of states and political subdivisions — — — — Home equity loans and lines of credit 212 264 1 — Auto loans 419 372 1 6 Other 29 8 — — Total Impaired Loans $ 14,506 $ 20,677 $ 210 $ 261
Classes of the Loan Portfolio, Internal Risk Rating System	The following tables present the classes of the loan portfolio summarized by the aggregate Pass and the criticized categories of Special Mention, Substandard, and Doubtful or Loss within the internal risk rating system at March 31, 2018 and September 30, 2017 (in thousands): Pass Special Mention Substandard Doubtful or Loss Total March 31, 2018 Commercial real estate loans $ 364,292 $ 1,368 $ 17,901 $ — $ 383,561 Commercial 46,889 354 2,030 — 49,273 Obligations of states and political subdivisions 55,615 — — — 55,615 Total $ 466,796 $ 1,722 $ 19,931 $ — $ 488,449 Pass Special Mention Substandard Doubtful or Loss Total September 30, 2017 Commercial real estate loans $ 300,554 $ 3,376 $ 14,393 $ — $ 318,323 Commercial 40,996 32 3,101 — 44,129 Obligations of states and political subdivisions 58,079 — — — 58,079 Total $ 399,629 $ 3,408 $ 17,494 $ — $ 420,531
Schedule of Performing or non-performing Loans	The following tables present the risk ratings in the consumer categories of performing and non-performing loans at March 31, 2018 and September 30, 2017 (in thousands): Performing Non- performing Purchased Credit Impaired Total March 31, 2018 Real estate loans: Residential $ 577,491 $ 6,435 $ — $ 583,926 Construction 4,072 — — 4,072 Home equity loans and lines of credit 43,615 304 328 44,247 Auto loans 177,698 722 — 178,420 Other 2,629 29 — 2,658 Total $ 805,505 $ 7,490 $ 328 $ 813,323 Performing Non- performing Purchased Impaired Credit Total September 30, 2017 Real estate loans: Residential $ 580,116 $ 6,592 $ — $ 586,708 Construction 3,097 — — 3,097 Home equity loans and lines of credit 45,576 313 330 46,219 Auto loans 185,910 736 — 186,646 Other 2,807 38 — 2,845 Total $ 817,506 $ 7,679 $ 330 $ 825,515
Classes of the Loan Portfolio Summarized by the Aging Categories	The following tables present the classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans as of March 31, 2018 and September 30, 2017 (in thousands): 31-60 Days 61-90 Days Greater than 90 Days Past Due and Total Purchased Credit Impaired Total Current Past Due Past Due Accruing Non­accrual Past Due Accruing Non­accrual Loans March 31, 2018 Real estate loans: Residential $ 575,286 $ 1,120 $ 1,085 $ — $ 6,435 $ 8,640 $ — $ — $ 583,926 Construction 4,072 — — — — — — — $ 4,072 Commercial 377,531 38 — — 2,092 2,130 261 3,639 $ 383,561 Commercial 48,910 — — — 111 111 — 252 $ 49,273 Obligations of states and political subdivisions 55,615 — — — — — — — $ 55,615 Home equity loans and lines of credit 43,456 159 — — 304 463 — 328 $ 44,247 Auto loans 176,631 951 116 — 722 1,789 — — $ 178,420 Other 2,629 — — — 29 29 — — $ 2,658 Total $ 1,284,130 $ 2,268 $ 1,201 $ — $ 9,693 $ 13,162 $ 261 $ 4,219 $ 1,301,772 31-60 Days 61-90 Days Greater than 90 Days Past Due and Total Purchased Credit Impaired Total Current Past Due Past Due Accruing Non­accrual Past Due Accruing Non­accrual Loans September 30, 2017 Real estate loans: Residential $ 577,034 $ 2,661 $ 421 $ — $ 6,592 $ 9,674 $ — $ — $ 586,708 Construction 3,097 — — — — — — — 3,097 Commercial 312,098 172 — — 2,278 2,450 612 3,163 318,323 Commercial 43,298 18 — — 530 548 — 283 44,129 Obligations of states and political subdivisions 58,079 — — — — — — — 58,079 Home equity loans and lines of credit 45,460 101 15 — 313 429 — 330 46,219 Auto loans 185,247 631 32 — 736 1,399 — — 186,646 Other 2,789 14 4 — 38 56 — — 2,845 Total $ 1,227,102 $ 3,597 $ 472 $ — $ 10,487 $ 14,556 $ 612 $ 3,776 $ 1,246,046
Summary of Primary Segments of ALL	The following table summarizes changes in the primary segments of the ALL for the three and six month periods ended March 31, 2018 and 2017 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total ALL balance at December 31, 2017 $ 3,769 $ 33 $ 2,319 $ 1,054 $ 213 $ 449 $ 1,962 $ 21 $ 13 $ 9,833 Charge-offs (52 ) — (14 ) (5 ) — (6 ) (550 ) (15 ) — (642 ) Recoveries 3 — — — — 3 211 2 — 219 Provision 35 — 516 170 56 (45 ) 281 13 74 1,100 ALL balance at March 31, 2018 $ 3,755 $ 33 $ 2,821 $ 1,219 $ 269 $ 401 $ 1,904 $ 21 $ 87 $ 10,510 ALL balance at December 31, 2016 $ 4,450 $ 23 $ 795 $ 965 $ 234 $ 441 $ 2,062 $ 25 $ 347 $ 9,342 Charge-offs (290 ) — (128 ) (1 ) — (6 ) (544 ) — — (969 ) Recoveries 5 — — — — 2 232 4 — 243 Provision (35 ) 7 371 (13 ) 10 8 158 (5 ) 249 750 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 ALL balance at September 30, 2017 $ 3,878 $ 23 $ 1,758 $ 987 $ 248 $ 470 $ 1,836 $ 21 $ 144 $ 9,365 Charge-offs (95 ) — (15 ) (137 ) — (6 ) (1,087 ) (21 ) — (1,361 ) Recoveries 6 — 2 10 — 5 381 2 — 406 Provision (34 ) 10 1,076 359 21 (68 ) 774 19 (57 ) 2,100 ALL balance at March 31, 2018 $ 3,755 $ 33 $ 2,821 $ 1,219 $ 269 $ 401 $ 1,904 $ 21 $ 87 $ 10,510 ALL balance at September 30, 2016 $ 4,426 $ 13 $ 852 $ 882 $ 215 $ 455 $ 1,880 $ 25 $ 308 $ 9,056 Charge-offs (366 ) — (218 ) (20 ) — (6 ) (1,061 ) (4 ) — (1,675 ) Recoveries 6 — 10 — — 3 460 6 — 485 Provision 64 17 394 89 29 (7 ) 629 (3 ) 288 1,500 ALL balance at March 31, 2017 $ 4,130 $ 30 $ 1,038 $ 951 $ 244 $ 445 $ 1,908 $ 24 $ 596 $ 9,366 Acquired loans are recorded at fair value on their purchase date without a carryover of the related allowance for loan losses. The Company allocated increased provisions to commercial real estate loans due primarily to increased loan balances for the three month period ended March 31, 2018. The Company allocated increased provisions to commercial loans due primarily to increase loan balances and charge off activity for the three month period ended March 31, 2018. The Company allocated increased provisions to commercial real estate loans for the three month period ended March 31, 2017 due to charge off activity. The Company allocated increased provisions to auto loans for the three and six month periods ended March 31, 2018 and 2017 due to increased charge offs, net of recoveries. The following table summarizes the primary segments of the ALL, segregated into two categories, the amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment as of March 31, 2018 and September 30, 2017 (in thousands): Home Obligations of Equity States and Loans and Real Estate Loans Commercial Political Lines of Other Residential Construction Commercial Loans Subdivisions Credit Auto Loans Loans Unallocated Total Individually evaluated for impairment $ 160 $ — $ 12 $ — $ — $ 2 $ 130 $ — $ — $ 304 Collectively evaluated for impairment 3,595 33 2,809 1,219 269 399 1,774 21 87 10,206 ALL balance at March 31, 2018 $ 3,755 $ 33 $ 2,821 $ 1,219 $ 269 $ 401 $ 1,904 $ 21 $ 87 $ 10,510 Individually evaluated for impairment $ 154 $ — $ 19 $ — $ — $ — $ 172 $ — $ — $ 345 Collectively evaluated for impairment 3,724 23 1,739 987 248 470 1,664 21 144 9,020 ALL balance at September 30, 2017 $ 3,878 $ 23 $ 1,758 $ 987 $ 248 $ 470 $ 1,836 $ 21 $ 144 $ 9,365
Summary of Troubled Debt Restructuring Granted	The following is a summary of troubled debt restructuring granted during the three and six months ended March 31, 2018 and 2017 (dollars in thousands): For the Three Months Ended March 31, 2018 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential — — — Construction — — — Commercial 1 107 107 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans 1 15 15 Other — — — Total 2 $ 122 $ 122 For the Three Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 1 $ 135 $ 135 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 3 $ 291 $ 291 For the Six Months Ended March 31, 2018 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 2 $ 243 $ 235 Construction — — — Commercial 1 107 107 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans 1 15 15 Other — — — Total 4 $ 365 $ 357 For the Six Months Ended March 31, 2017 Number of Contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Troubled Debt Restructurings Real estate loans: Residential 3 $ 379 $ 379 Construction — — — Commercial 1 132 132 Commercial — — — Obligations of states and political subdivisions — — — Home equity loans and lines of credit — — — Auto loans — — — Other 1 24 24 Total 5 $ 535 $ 535

Deposits (Tables)

Deposits (Tables)	6 Months Ended
	Mar. 31, 2018
Banking And Thrift [Abstract]
Schedule of Deposits by Major Classifications	Deposits consist of the following major classifications (in thousands): March 31, 2018 September 30, 2017 Non-interest bearing demand accounts $ 152,379 $ 160,125 Interest bearing demand accounts 164,611 208,369 Money market accounts 266,927 253,949 Savings and club accounts 143,715 141,521 Certificates of deposit 511,721 510,897 Total $ 1,239,353 $ 1,274,861

Net Periodic Benefit Cost-Def28

Net Periodic Benefit Cost-Defined Benefit Plan (Tables)	6 Months Ended
	Mar. 31, 2018
Compensation And Retirement Disclosure [Abstract]
Summary of the Components of Net Periodic Benefit Cost	The following table comprises the components of net periodic benefit cost for the three and six month periods ended March 31, 2018 and 2017 (in thousands): For the Three Months Ended March 31, For the Six Months Ended March 31, 2018 2017 2018 2017 Service Cost $ — $ 69 $ — $ 378 Interest Cost 175 208 349 443 Expected return on plan assets (299 ) (348 ) (597 ) (689 ) Amortization of unrecognized loss — 23 — 159 Net periodic benefit cost $ (124 ) $ (48 ) $ (248 ) $ 291

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	6 Months Ended
	Mar. 31, 2018
Postemployment Benefits [Abstract]
Schedule of Stock Option Activity	The following is a summary of the Company’s stock option activity and related information for its option grants for the six month period ended March 31, 2018. Number of Stock Options Weighted- average Exercise Price Weighted- average Remaining Contractual Term (in Aggregate Intrinsic Value (in thousands) Outstanding at September 30, 2017 294,646 $ 12.35 0.67 $ 987 Granted — — — — Exercised 196,848 12.35 0.17 — Forfeited — — — — Outstanding at March 31, 2018 97,798 $ 12.35 0.17 $ 227 Exercisable at March 31, 2018 97,798 $ 12.35 0.17 $ 227
Schedule of Restricted Stock Option Activity	The following is a summary of the status of the Company’s restricted stock as of March 31, 2018, and changes therein during the six month period then ended: Number of Restricted Weighted- average Grant Date Fair Value Nonvested at September 30, 2017 34,692 $ 14.89 Granted 25,528 15.86 Vested (1,000 ) — Forfeited (2,535 ) 14.79 Nonvested at March 31, 2018 56,685 $ 15.31

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Securities, Derivatives, Other Real Estate Owned and Impaired Loans Measured at Fair Value	The following tables present information about the Company’s securities, derivatives, other real estate owned, impaired loans and mortgage servicing rights measured at fair value as of March 31, 2018 and September 30, 2017 and indicates the fair value hierarchy of the valuation techniques utilized by the Bank to determine such fair value: Fair Value Measurement at March 31, 2018 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of March 31, 2018 Assets measured at fair value on a recurring basis: Investment securities available for sale: Mortgage backed securities $ — $ 246,708 $ — $ 246,708 Obligations of states and political subdivisions — 51,362 — 51,362 U.S. government agencies — 13,108 — 13,108 Corporate obligations — 37,221 7,767 44,988 Other debt securities — 21,184 — 21,184 Equity securities-financial services 25 — — 25 Total Securities $ 25 $ 369,583 $ 7,767 $ 377,375 Derivatives and hedging activities: $ — $ 2,312 $ — $ 2,312 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 1,279 $ 1,279 Impaired loans $ — $ — $ 13,614 $ 13,614 Mortgage servicing rights $ — $ — $ 220 $ 220 Fair Value Measurement at September 30, 2017 Fair Value Measurements Utilized for the Company’s Financial Assets (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balances as of September 30, 2017 Assets measured at fair value on a recurring basis: Investment securities available for sale: Mortgage backed securities $ — $ 233,823 $ — $ 233,823 Obligations of states and political subdivisions — 65,358 — 65,358 U.S. government agencies — 18,671 — 18,671 Corporate obligations — 41,518 7,224 48,742 Other debt securities — 23,833 — 23,833 Equity securities-financial services 25 — — 25 Total Securities $ 25 $ 383,203 $ 7,224 $ 390,452 Derivatives and hedging activities $ — $ 1,215 $ — $ 1,215 Assets measured at fair value on a nonrecurring basis: Foreclosed real estate $ — $ — $ 1,424 $ 1,424 Impaired loans $ — $ — $ 15,231 $ 15,231 Mortgage Servicing rights $ — $ — $ 232 $ 232
Schedule of Changes in Fair Value of Level III Investments	The following tables present a summary of changes in the fair value of the Company’s Level III investments for the three and six month periods ended March 31, 2018 and 2017 (in thousands). Fair Value Measurement Using Significant Unobservable Inputs (Level III) Three Months Ended March 31, 2018 March 31, 2017 Beginning balance $ 7,826 $ 8,238 Purchases, sales, issuances, settlements, net — 756 Total unrealized gain (loss): Included in earnings — — Included in other comprehensive loss (59 ) (259 ) Transfers in and/or out of Level III — — $ 7,767 $ 8,735 Fair Value Measurement Using Significant Unobservable Inputs (Level III) Six Months Ended March 31, 2018 March 31, 2017 Beginning balance $ 7,224 $ 7,485 Purchases, sales, issuances, settlements, net 500 756 Total unrealized gain (loss): Included in earnings — — Included in other comprehensive income 43 494 Transfers in and/or out of Level III — — $ 7,767 $ 8,735
Summary of Additional Quantitative Information about Assets Measured at Fair Value on a Nonrecurring Basis	The following tables present additional quantitative information about assets measured at fair value on a nonrecurring basis and for which the Company has utilized Level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range March 31, 2018 Impaired loans $ 13,614 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 35% (25.3%) Foreclosed real estate owned 1,279 Appraisal of collateral (1), (3) Appraisal adjustments (2) 20% to 46% (23.2%) Mortgage servicing rights 220 Discounted cash flow Discount rate 11.0% (11.0%) Prepayment speeds 7% to 28% (12.2%) Quantitative Information about Level 3 Fair Value Measurements (in thousands) Fair Value Estimate Valuation Techniques Unobservable Input Range September 30, 2017 Impaired loans $ 15,231 Appraisal of collateral (1) Appraisal adjustments (2) 0% to 57% (24.0%) Foreclosed real estate owned 1,424 Appraisal of collateral (1), (3) Appraisal adjustments (2) 20% to 46% (22.0%) Mortgage servicing rights 232 Discounted cash flow Discount rate 11.0% (11.0%) Prepayment speeds 11% to 30% (15.9%) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range of liquidation expenses and other appraisal adjustments are presented as a percent of the appraisal.
Schedule of Estimate of Fair Value Using Methodologies	The fair values presented represent the Company’s best estimate of fair value using the methodologies discussed below (in thousands). March 31, 2018 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 34,804 $ 34,804 $ — $ — $ 34,804 Certificates of deposit 500 — — 501 501 Investment and mortgage backed securities available for sale 377,375 25 369,583 7,767 377,375 Loans receivable, net 1,291,262 — — 1,265,713 1,265,713 Accrued interest receivable 6,279 6,279 — — 6,279 Regulatory stock 17,234 17,234 — — 17,234 Mortgage servicing rights 220 — — 220 220 Derivatives 2,312 — 2,312 — 2,312 Bank owned life insurance 38,130 38,130 — — 38,130 Financial liabilities: Deposits $ 1,239,353 $ 727,632 $ — $ 508,654 $ 1,236,286 Short-term borrowings 241,345 241,345 — — 241,345 Other borrowings 139,434 — — 138,434 138,434 Advances by borrowers for taxes and insurance 12,188 12,188 — — 12,188 Accrued interest payable 1,077 1,077 — — 1,077 September 30, 2017 Carrying Level I Level II Level III Total Fair Value Financial assets: Cash and cash equivalents $ 41,683 $ 41,683 $ — $ — $ 41,683 Certificates of deposit 500 — — 505 505 Investment and mortgage backed securities available for sale 390,452 25 383,203 7,224 390,452 Loans receivable, net 1,236,681 — — 1,235,368 1,235,368 Accrued interest receivable 6,149 6,149 — — 6,149 Regulatory stock 13,832 13,832 — — 13,832 Mortgage servicing rights 232 — — 232 232 Derivatives 1,215 — 1,215 — 1,215 Bank owned life insurance 37,626 37,626 — — 37,626 Financial liabilities: Deposits $ 1,274,861 $ 763,964 $ — $ 511,392 $ 1,275,356 Short-term borrowings 137,446 137,446 — — 137,446 Other borrowings 174,168 — — 174,107 174,107 Advances by borrowers for taxes and insurance 5,163 5,163 — — 5,163 Accrued interest payable 1,043 1,043 — — 1,043

Accumulated Other Comprehensi31

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Summary of Activity in Accumulated Other Comprehensive Income (Loss)	The activity in accumulated other comprehensive loss for the three and six months period ended March 31, 2018 and 2017 is as follows (in thousands): Accumulated Other Comprehensive Loss Defined Benefit Pension Plan Unrealized (Losses) on Securities Available for Sale Derivatives Total Balance at December 31, 2017 $ (628 ) $ (2,215 ) $ 1,087 $ (1,756 ) Other comprehensive income before reclassifications — (5,100 ) 587 (4,513 ) Amounts reclassified from accumulated other comprehensive loss — (57 ) (63 ) (120 ) Reclassification of certain income tax effects from accumulated other comprehensive income (124 ) (436 ) 214 (346 ) Period change (124 ) (5,593 ) 738 (4,979 ) Balance at March 31, 2018 $ (752 ) $ (7,808 ) $ 1,825 $ (6,735 ) Balance at December 31, 2016 $ (5,993 ) $ (2,801 ) $ 899 $ (7,895 ) Other comprehensive income before reclassifications 4,714 781 25 5,520 Amounts reclassified from accumulated other comprehensive loss, net of tax 13 — (2 ) 11 Period change 4,727 781 23 5,531 Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 ) Accumulated Other Comprehensive Income/(Loss) Defined Benefit Pension Plan Unrealized Gains (Losses) on Securities Available for Sale Derivatives Total Balance at September 30, 2017 $ (628 ) $ (927 ) $ 801 $ (754 ) Other comprehensive income (loss) before reclassifications — (6,388 ) 888 (5,500 ) Amounts reclassified from accumulated other comprehensive loss, net of tax — (57 ) (78 ) (135 ) Reclassification of certain income tax effects from accumulated other comprehensive income (124 ) (436 ) 214 (346 ) Period change (124 ) (6,881 ) 1,024 (5,635 ) Balance at March 31, 2018 $ (752 ) $ (7,808 ) $ 1,825 $ (6,735 ) Balance at September 30, 2016 $ (6,083 ) $ 3,952 $ 299 $ (1,832 ) Other comprehensive income before reclassifications 4,714 (5,972 ) 619 (639 ) Amounts reclassified from accumulated other comprehensive loss, net of tax 103 — 4 107 Period change 4,817 (5,972 ) 623 (532 ) Balance at March 31, 2017 $ (1,266 ) $ (2,020 ) $ 922 $ (2,364 )
Summary of Reclassification Out of Accumulated Other Comprehensive Income (Loss)	The following table presents significant amounts reclassified out of each component of accumulated other comprehensive loss for the three and six month periods ended March 31, 2018 and 2017 (in thousands): Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss for the Three Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2018 2017 Securities available for sale Net securities gains reclassified into earnings 75 — Gains on sale of investments, net Related income tax expense (18 ) — Income taxes Net effect on accumulated other comprehensive loss for the period 57 — Net of tax Defined benefit pension plan: Amortization of net (loss) gain and prior service costs — (23 ) Compensation and employee Related income tax expense — 10 Income taxes Net effect on accumulated other comprehensive loss for the period — (13 ) Net of tax Derivatives and hedging activities: Interest expense, effective portion 76 5 Interest expense Related income tax expense (13 ) (3 ) Income taxes Net effect on accumulated other comprehesive loss for the period 63 2 Net of tax Total reclassification for the period $ 120 $ (11 ) Amount Reclassified from Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss For the Six Months Ended March 31, Affected Line Item in the Consolidated Statement of Income 2018 2017 Securities available for sale: Net securities gains reclassified into earnings 75 — Gain on sale of investments, net Related income tax expense (18 ) — Income taxes Net effect on accumulated other comprehensive loss for the period 57 — Net of tax Defined benefit pension plan: Amoritization of net (loss) gain and prior services costs — (159 ) Compensation and employee benefits Related income tax expense — 56 Income taxes Net effect on accumulated other comprehensive loss for the period — (103 ) Net of tax Derivative and Hedging Activities: Interest expense, effective portion 99 (6 ) Interest expense Related income tax expense (21 ) 2 Income taxes Net effect on accumulated other comprehensive loss for the period 78 (4 ) Net of tax Total reclassification for the period $ 135 $ (107 )

Derivatives and Hedging Activit

Derivatives and Hedging Activities (Tables)	6 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Schedule of Fair Value of Derivative Financial Instruments as well as their Classification on Consolidated Balance Sheet	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Balance Sheet as of March 31, 2018 and September 30, 2017 (in thousands). Fair Values of Derivative Instruments Asset Derivatives As of March 31, 2018 As of September 30, 2017 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest Rate Products Other Assets $ 2,312 Other Assets $ 1,215
Schedule of Pre-Tax Net Gains (Losses) of Cash flow Hedges	The tables below present the pre-tax net gains (losses) of the Company’s cash flow hedges for the three month periods ended March 31, 2018 and 2017, respectively, and where they were recorded in the Consolidated Statement of Income, (in thousands). Derivatives in Cash Flow Hedging Relationships Loss Recognized in OCI on Derivative (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) Three Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Three Months Ended March 31, 2018 2017 2018 2017 2018 2017 Interest Rate Products $ 738 $ 40 Interest expense $ 76 $ 5 Other non-interest income $ — $ — Ending balance of OCI Total $ 738 $ 40 $ 76 $ 5 $ — $ — Derivatives in Cash Flow Hedging Relationships Gain Recognized in OCI on Derivative (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) (Loss)Reclassified from Accumulated OCI into Income (Effective Portion) Six Months Ended March 31, Location of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion) Six Months Ended March 31, 2018 2017 2018 2017 2018 2017 Interest Rate Products $ 1,195 $ 1,092 Interest expense $ 99 $ (6 ) Other non-interest income $ — $ — Ending balance of OCI Total $ 1,195 $ 1,092 $ 99 $ (6 ) $ — $ —

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of the Federal Statutory Rate and the Effective Income Tax Rate	The reconciliation of the federal statutory rate and the Company’s effective income tax rate is as follows (in thousands): For the Three Months Ended March 31, 2018 2017 Amount % of Pretax Income Amount % of Pretax Income Provision at statutory rate $ 676 24.2 % $ 622 34.0 % Income from bank-owned life insurance (60 ) (2.2 ) (86 ) (4.7 ) Tax-exempt income (134 ) (4.8 ) (216 ) (11.8 ) Low-income housing credits 52 1.9 (74 ) (4.0 ) Other, net (5 ) (0.2 ) (43 ) (2.3 ) Actual tax expense and effective rate $ 529 18.9 % $ 203 11.2 % For the Six Months Ended March 31, 2018 2017 Amount % of Pretax Income Amount % of Pretax Income Provision at statutory rate $ 1,271 24.2 % $ 1,417 34.0 % Income from bank-owned life insurance (122 ) (2.3 ) (176 ) (4.2 ) Tax-exempt income (269 ) (5.1 ) (432 ) (10.4 ) Low-income housing credits (43 ) (0.8 ) (123 ) (2.9 ) Tax rate change 3,780 72.1 — — Other, net 5 (0.1 ) (83 ) (2.0 ) Actual tax expense and effective rate $ 4,622 88.1 % $ 603 14.5 %

Nature of Operations and Basi34

Nature of Operations and Basis of Presentation - Additional Information (Detail)	Mar. 31, 2018
ESSA Advisory Services, LLC [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage ownership of wholly owned subsidiary	100.00%

Earnings Per Share - Compositio

Earnings Per Share - Composition of the Weighted-Average Common Shares (Denominator) Used in the Basic and Diluted Earnings per Share Computation (Detail) - shares	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Weighted-average common shares outstanding	18,133,095	18,133,095	18,133,095	18,133,095
Average treasury stock shares	(6,459,392)	(6,618,067)	(6,490,961)	(6,670,049)
Average unearned ESOP shares	(843,010)	(888,285)	(848,729)	(894,004)
Average unearned non-vested shares	(34,340)	(33,746)	(44,318)	(42,958)
Weighted average common shares and common stock equivalents used to calculate basic earnings per share	10,796,353	10,592,997	10,749,087	10,526,084
Additional common stock equivalents (non-vested stock) used to calculate diluted earnings per share	347	1,646	143
Additional common stock equivalents (stock options) used to calculate diluted earnings per share	25,409	97,317	31,149	91,157
Weighted average common shares and common stock equivalents used to calculate diluted earnings per share	10,822,109	10,691,960	10,780,379	10,617,241

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - Stock Option [Member] - $ / shares	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	53,313	53,371
Average weighted price per share of anti-dilutive shares	$ 15.24	$ 11.77

Recent Accounting Pronounceme37

Recent Accounting Pronouncements - Additional Information (Detail) $ in Thousands	6 Months Ended
	Mar. 31, 2018USD ($)
ASU 2016-02, Leases [Member] | Maximum [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Estimated percentage increase in assets from recognition of leases	1.00%
Estimated percentage increase in liabilities from recognition of leases	1.00%
ASU 2018-02 [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Reclassification between accumulated other comprehensive income and retained earnings	$ 346,000

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Investment Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	$ 387,258	$ 391,857
Available for sale, Gross Unrealized Gains	912	2,392
Available for sale, Gross Unrealized Losses	(10,795)	(3,797)
Available for sale, Fair Value	377,375	390,452
Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	136,157	119,333
Available for sale, Gross Unrealized Gains	15	207
Available for sale, Gross Unrealized Losses	(3,880)	(1,203)
Available for sale, Fair Value	132,292	118,337
Freddie Mac [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	97,336	98,668
Available for sale, Gross Unrealized Gains	5	177
Available for sale, Gross Unrealized Losses	(3,113)	(808)
Available for sale, Fair Value	94,228	98,037
Governmental National Mortgage Association Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	20,845	17,609
Available for sale, Gross Unrealized Gains		43
Available for sale, Gross Unrealized Losses	(657)	(203)
Available for sale, Fair Value	20,188	17,449
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	254,338	235,610
Available for sale, Gross Unrealized Gains	20	427
Available for sale, Gross Unrealized Losses	(7,650)	(2,214)
Available for sale, Fair Value	246,708	233,823
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	52,046	64,382
Available for sale, Gross Unrealized Gains	621	1,522
Available for sale, Gross Unrealized Losses	(1,305)	(546)
Available for sale, Fair Value	51,362	65,358
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	13,191	18,615
Available for sale, Gross Unrealized Gains	26	61
Available for sale, Gross Unrealized Losses	(109)	(5)
Available for sale, Fair Value	13,108	18,671
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	45,748	49,025
Available for sale, Gross Unrealized Gains	242	335
Available for sale, Gross Unrealized Losses	(1,002)	(618)
Available for sale, Fair Value	44,988	48,742
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	21,910	24,200
Available for sale, Gross Unrealized Gains	3	47
Available for sale, Gross Unrealized Losses	(729)	(414)
Available for sale, Fair Value	21,184	23,833
Total Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	387,233	391,832
Available for sale, Gross Unrealized Gains	912	2,392
Available for sale, Gross Unrealized Losses	(10,795)	(3,797)
Available for sale, Fair Value	377,350	390,427
Equity Securities-Financial Services [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, Amortized Cost	25	25
Available for sale, Fair Value	$ 25	$ 25

Investment Securities - Schedul

Investment Securities - Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Due in one year or less, Amortized Cost	$ 1,748
Due after one year through five years, Amortized Cost	34,694
Due after five years through ten years, Amortized Cost	100,607
Due after ten years, Amortized Cost	250,184
Total, Amortized Cost	387,233
Due in one year or less, Fair Value	1,750
Due after one year through five years, Fair Value	34,396
Due after five years through ten years, Fair Value	98,495
Due after ten years, Fair Value	242,709
Total, Fair Value	$ 377,350

Investment Securities - Additio

Investment Securities - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Amortized Cost And Fair Value Debt Securities [Abstract]
Realized gross gains	$ 300,000	$ 0	$ 300,000	$ 0
Realized gross losses	225,000	0	225,000	0
Proceeds from the sale of investment securities	$ 22,100,000	$ 0	$ 22,100,000	$ 0

Investment Securities - Sched41

Investment Securities - Schedule of Gross Unrealized Losses and Fair Value (Detail) $ in Thousands	Mar. 31, 2018USD ($)Security	Sep. 30, 2017USD ($)Security
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	255	174
Fair Value, Less than Twelve Months	$ 201,907	$ 149,633
Gross Unrealized Losses, Less than Twelve Months	(4,263)	(1,225)
Fair Value, Twelve Months or Greater	131,378	83,272
Gross Unrealized Losses, Twelve Months or Greater	(6,532)	(2,572)
Fair Value, Total	333,285	232,905
Gross Unrealized Losses, Total	$ (10,795)	$ (3,797)
Fannie Mae [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	90	55
Fair Value, Less than Twelve Months	$ 84,342	$ 61,852
Gross Unrealized Losses, Less than Twelve Months	(1,691)	(558)
Fair Value, Twelve Months or Greater	45,723	20,679
Gross Unrealized Losses, Twelve Months or Greater	(2,189)	(645)
Fair Value, Total	130,065	82,531
Gross Unrealized Losses, Total	$ (3,880)	$ (1,203)
Freddie Mac [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	68	39
Fair Value, Less than Twelve Months	$ 61,564	$ 38,913
Gross Unrealized Losses, Less than Twelve Months	(1,553)	(354)
Fair Value, Twelve Months or Greater	31,808	16,427
Gross Unrealized Losses, Twelve Months or Greater	(1,560)	(454)
Fair Value, Total	93,372	55,340
Gross Unrealized Losses, Total	$ (3,113)	$ (808)
Governmental National Mortgage Association [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	17	11
Fair Value, Less than Twelve Months	$ 13,429	$ 6,669
Gross Unrealized Losses, Less than Twelve Months	(309)	(41)
Fair Value, Twelve Months or Greater	6,759	6,903
Gross Unrealized Losses, Twelve Months or Greater	(348)	(162)
Fair Value, Total	20,188	13,572
Gross Unrealized Losses, Total	$ (657)	$ (203)
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	28	25
Fair Value, Less than Twelve Months	$ 11,431	$ 10,944
Gross Unrealized Losses, Less than Twelve Months	(217)	(59)
Fair Value, Twelve Months or Greater	19,765	17,425
Gross Unrealized Losses, Twelve Months or Greater	(1,088)	(487)
Fair Value, Total	31,196	28,369
Gross Unrealized Losses, Total	$ (1,305)	$ (546)
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	4	3
Fair Value, Less than Twelve Months	$ 8,718	$ 8,995
Gross Unrealized Losses, Less than Twelve Months	(109)	(5)
Fair Value, Total	8,718	8,995
Gross Unrealized Losses, Total	$ (109)	$ (5)
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	29	22
Fair Value, Less than Twelve Months	$ 20,338	$ 15,119
Gross Unrealized Losses, Less than Twelve Months	(350)	(104)
Fair Value, Twelve Months or Greater	9,465	8,032
Gross Unrealized Losses, Twelve Months or Greater	(652)	(514)
Fair Value, Total	29,803	23,151
Gross Unrealized Losses, Total	$ (1,002)	$ (618)
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities | Security	19	19
Fair Value, Less than Twelve Months	$ 2,085	$ 7,141
Gross Unrealized Losses, Less than Twelve Months	(34)	(104)
Fair Value, Twelve Months or Greater	17,858	13,806
Gross Unrealized Losses, Twelve Months or Greater	(695)	(310)
Fair Value, Total	19,943	20,947
Gross Unrealized Losses, Total	$ (729)	$ (414)

Loans Receivable, Net and All42

Loans Receivable, Net and Allowance for Loan Losses - Summary of Loans Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016
Real estate loans:
Total Loans	$ 1,301,772		$ 1,246,046
Less allowance for loan losses	10,510	$ 9,833	9,365	$ 9,366	$ 9,342	$ 9,056
Net loans	1,291,262		1,236,681
Residential Real Estate Loans [Member]
Real estate loans:
Total Loans	583,926		586,708
Less allowance for loan losses	3,755	3,769	3,878	4,130	4,450	4,426
Construction Real Estate Loans [Member]
Real estate loans:
Total Loans	4,072		3,097
Commercial Real Estate Loans [Member]
Real estate loans:
Total Loans	383,561		318,323
Less allowance for loan losses	2,821	2,319	1,758	1,038	795	852
Commercial Loans [Member]
Real estate loans:
Total Loans	49,273		44,129
Less allowance for loan losses	1,219	1,054	987	951	965	882
Obligations of States and Political Subdivisions [Member]
Real estate loans:
Total Loans	55,615		58,079
Less allowance for loan losses	269	213	248	244	234	215
Home Equity Loans and Lines of Credit [Member]
Real estate loans:
Total Loans	44,247		46,219
Less allowance for loan losses	401	449	470	445	441	455
Auto Loans [Member]
Real estate loans:
Total Loans	178,420		186,646
Less allowance for loan losses	1,904	1,962	1,836	1,908	2,062	1,880
Other [Member]
Real estate loans:
Total Loans	2,658		2,845
Less allowance for loan losses	$ 21	$ 21	$ 21	$ 24	$ 25	$ 25

Loans Receivable, Net and All43

Loans Receivable, Net and Allowance for Loan Losses - Changes in Accretable Yield for Purchased Credit-Impaired Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Receivables [Abstract]
Balance at beginning of period	$ 755	$ 453	$ 471	$ 478
Reclassification, new additions and other	85	82	681	118
Accretion	(266)	(75)	(578)	(136)
Balance at end of period	$ 574	$ 460	$ 574	$ 460

Loans Receivable, Net and All44

Loans Receivable, Net and Allowance for Loan Losses - Summary of Additional Information Regarding Loans Acquired and Accounted (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	$ 1,301,772	$ 1,246,046
Loans Acquired with Deteriorated Credit Quality [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	4,852	5,490
Carrying amount	$ 4,480	$ 4,388

Loans Receivable, Net and All45

Loans Receivable, Net and Allowance for Loan Losses - Schedule of Loans Evaluated for Impairment (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 1,301,772	$ 1,246,046
Individually Evaluated for Impairment	13,918	15,576
Collectively Evaluated for Impairment	1,283,374	1,226,082
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,480	4,388
Residential Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	583,926	586,708
Individually Evaluated for Impairment	5,190	6,202
Collectively Evaluated for Impairment	578,736	580,506
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	383,561	318,323
Individually Evaluated for Impairment	6,803	7,211
Collectively Evaluated for Impairment	372,858	307,337
Commercial Real Estate Loans [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	3,900	3,775
Commercial Real Estate Loans [Member] | Construction Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	4,072	3,097
Collectively Evaluated for Impairment	4,072	3,097
Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	49,273	44,129
Individually Evaluated for Impairment	1,142	1,385
Collectively Evaluated for Impairment	47,879	42,461
Commercial Loans [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	252	283
Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	55,615	58,079
Collectively Evaluated for Impairment	55,615	58,079
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	44,247	46,219
Individually Evaluated for Impairment	198	176
Collectively Evaluated for Impairment	43,721	45,713
Home Equity Loans and Lines of Credit [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	328	330
Auto Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	178,420	186,646
Individually Evaluated for Impairment	558	572
Collectively Evaluated for Impairment	177,862	186,074
Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,658	2,845
Individually Evaluated for Impairment	27	30
Collectively Evaluated for Impairment	$ 2,631	$ 2,815

Loans Receivable, Net and All46

Loans Receivable, Net and Allowance for Loan Losses - Schedule of Investment and Unpaid Principal Balances for Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2017
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 13,918		$ 13,918		$ 15,576
Unpaid Principal Balance	17,924		17,924		21,157
Associated Allowance	304		304		345
Average Recorded Investment	14,104	$ 19,462	14,506	$ 20,677
Interest	99	107	210	261
With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	12,219		12,219		13,297
Unpaid Principal Balance	15,959		15,959		17,232
Average Recorded Investment	12,586	16,740	12,841	17,991
Interest	99	105	210	255
With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,699		1,699		2,279
Unpaid Principal Balance	1,965		1,965		3,925
Associated Allowance	304		304		345
Average Recorded Investment	1,518	2,722	1,665	2,686
Interest		2		6
Residential Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	5,190		5,190		6,202
Unpaid Principal Balance	6,754		6,754		7,994
Associated Allowance	160		160		154
Average Recorded Investment	5,436	7,558	5,697	8,074
Interest	6	9	16	21
Residential Real Estate Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	3,879		3,879		4,392
Unpaid Principal Balance	5,193		5,193		5,730
Average Recorded Investment	4,180	5,573	4,305	6,049
Interest	6	9	16	21
Residential Real Estate Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,311		1,311		1,810
Unpaid Principal Balance	1,561		1,561		2,264
Associated Allowance	160		160		154
Average Recorded Investment	1,256	1,985	1,392	2,025
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	6,803		6,803		7,211
Unpaid Principal Balance	8,751		8,751		10,589
Associated Allowance	12		12		19
Average Recorded Investment	6,808	9,559	6,916	10,235
Interest	69	67	141	172
Commercial Real Estate Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	6,785		6,785		7,191
Unpaid Principal Balance	8,729		8,729		9,396
Average Recorded Investment	6,789	9,218	6,897	9,890
Interest	69	67	141	172
Commercial Real Estate Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	18		18		20
Unpaid Principal Balance	22		22		1,193
Associated Allowance	12		12		19
Average Recorded Investment	19	341	19	345
Commercial Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,142		1,142		1,385
Unpaid Principal Balance	1,397		1,397		1,575
Average Recorded Investment	1,178	1,737	1,233	1,724
Interest	24	29	51	62
Commercial Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,142		1,142		1,385
Unpaid Principal Balance	1,397		1,397		1,575
Average Recorded Investment	1,178	1,637	1,233	1,665
Interest	24	29	51	62
Commercial Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment		100		59
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	198		198		176
Unpaid Principal Balance	213		213		258
Associated Allowance	2		2
Average Recorded Investment	215	207	212	264
Interest			1
Home Equity Loans and Lines of Credit [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	172		172		176
Unpaid Principal Balance	186		186		258
Average Recorded Investment	203	202	205	260
Interest			1
Home Equity Loans and Lines of Credit [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	26		26
Unpaid Principal Balance	27		27
Associated Allowance	2		2
Average Recorded Investment	12	5	7	4
Auto Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	558		558		572
Unpaid Principal Balance	775		775		705
Associated Allowance	130		130		172
Average Recorded Investment	439	393	419	372
Interest		2	1	6
Auto Loans [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	214		214		123
Unpaid Principal Balance	420		420		237
Average Recorded Investment	208	102	172	119
Interest			1
Auto Loans [Member] | With an Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	344		344		449
Unpaid Principal Balance	355		355		468
Associated Allowance	130		130		172
Average Recorded Investment	231	291	247	253
Interest		2		6
Other [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	27		27		30
Unpaid Principal Balance	34		34		36
Average Recorded Investment	28	8	29	8
Other [Member] | With no Specific Allowance Recorded [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	27		27		30
Unpaid Principal Balance	34		34		$ 36
Average Recorded Investment	$ 28	$ 8	$ 29	$ 8

Loans Receivable, Net and All47

Loans Receivable, Net and Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Mar. 31, 2018USD ($)Contract	Mar. 31, 2017USD ($)Contract	Mar. 31, 2018USD ($)Contract	Mar. 31, 2017USD ($)Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Criteria in internal rating system	Ten-point
Categories considered as not criticized	six
Days past due over which loans are considered as substandard	90 days
Minimum internal review amount	$ 750,000		$ 750,000
Minimum external review amount	$ 1,000,000		$ 1,000,000
Number of troubled debt restructuring loans granted terms concessions | Contract	1	1	1	1
Troubled debt restructurings granted terms concession	$ 107,000	$ 135,000	$ 107,000	$ 135,000
Number of troubled debt restructuring loans granted terms and rate concessions | Contract	1	1	3	3
Troubled debt restructurings granted terms and rate concession	$ 15,000	$ 132,000	$ 250,000	$ 376,000
Number of Contracts | Contract		3		5
Number of troubled debt restructuring loans granted interest rate concession | Contract		1		1
Troubled debt restructurings loans granted interest rate concession		$ 24,000		$ 24,000
Number of troubled debt restructurings, loan modified, defaulted within one year of modification | Contract	1	0	2	1
Troubled debt restructurings, loan modified, defaulted within one year of modification	$ 72,000		$ 95,000	$ 107,000
Consumer Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreclosed assets	790,000		790,000
Formal foreclosure proceeding assets	$ 2,600,000		$ 2,600,000

Loans Receivable, Net and All48

Loans Receivable, Net and Allowance for Loan Losses - Classes of Loan Portfolio, Internal Risk Rating System (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	$ 1,291,262	$ 1,236,681
Commercial And Municipal Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	488,449	420,531
Commercial And Municipal Portfolio Segment | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	383,561	318,323
Commercial And Municipal Portfolio Segment | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	49,273	44,129
Commercial And Municipal Portfolio Segment | Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	55,615	58,079
Commercial And Municipal Portfolio Segment | Pass [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	466,796	399,629
Commercial And Municipal Portfolio Segment | Pass [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	364,292	300,554
Commercial And Municipal Portfolio Segment | Pass [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	46,889	40,996
Commercial And Municipal Portfolio Segment | Pass [Member] | Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	55,615	58,079
Commercial And Municipal Portfolio Segment | Special Mention [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	1,722	3,408
Commercial And Municipal Portfolio Segment | Special Mention [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	1,368	3,376
Commercial And Municipal Portfolio Segment | Special Mention [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	354	32
Commercial And Municipal Portfolio Segment | Substandard [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	19,931	17,494
Commercial And Municipal Portfolio Segment | Substandard [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	17,901	14,393
Commercial And Municipal Portfolio Segment | Substandard [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loan, total	$ 2,030	$ 3,101

Loans Receivable, Net and All49

Loans Receivable, Net and Allowance for Loan Losses - Schedule of Performing or Non-Performing Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Financing Receivable, Recorded Investment [Line Items]
Total	$ 1,291,262	$ 1,236,681
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	813,323	825,515
Purchase Credit Impaired [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	328	330
Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	805,505	817,506
Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	7,490	7,679
Residential Real Estate Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	583,926	586,708
Residential Real Estate Loans [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	577,491	580,116
Residential Real Estate Loans [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,435	6,592
Commercial Real Estate Loans [Member] | Construction Real Estate Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	4,072	3,097
Commercial Real Estate Loans [Member] | Performing [Member] | Construction Real Estate Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	4,072	3,097
Home Equity Loans and Lines of Credit [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	44,247	46,219
Home Equity Loans and Lines of Credit [Member] | Purchase Credit Impaired [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	328	330
Home Equity Loans and Lines of Credit [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	43,615	45,576
Home Equity Loans and Lines of Credit [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	304	313
Auto Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	178,420	186,646
Auto Loans [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	177,698	185,910
Auto Loans [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	722	736
Other [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	2,658	2,845
Other [Member] | Performing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	2,629	2,807
Other [Member] | Nonperforming [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 29	$ 38

Loans Receivable, Net and All50

Loans Receivable, Net and Allowance for Loan Losses - Classes of Loan Portfolio Summarized by Aging Categories (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 1,284,130	$ 1,227,102
31-60 Days Past Due	2,268	3,597
61-90 Days Past Due	1,201	472
Non-accrual	9,693	10,487
Total Past Due	13,162	14,556
Purchased Credit Impaired, Accruing	261	612
Purchased Credit Impaired, Nonaccrual	4,219	3,776
Total Loans	1,301,772	1,246,046
Residential Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	575,286	577,034
31-60 Days Past Due	1,120	2,661
61-90 Days Past Due	1,085	421
Non-accrual	6,435	6,592
Total Past Due	8,640	9,674
Total Loans	583,926	586,708
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	4,072	3,097
Total Loans	4,072	3,097
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	377,531	312,098
31-60 Days Past Due	38	172
Non-accrual	2,092	2,278
Total Past Due	2,130	2,450
Purchased Credit Impaired, Accruing	261	612
Purchased Credit Impaired, Nonaccrual	3,639	3,163
Total Loans	383,561	318,323
Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	48,910	43,298
31-60 Days Past Due		18
Non-accrual	111	530
Total Past Due	111	548
Purchased Credit Impaired, Nonaccrual	252	283
Total Loans	49,273	44,129
Obligations of States and Political Subdivisions [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	55,615	58,079
Total Loans	55,615	58,079
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	43,456	45,460
31-60 Days Past Due	159	101
61-90 Days Past Due		15
Non-accrual	304	313
Total Past Due	463	429
Purchased Credit Impaired, Nonaccrual	328	330
Total Loans	44,247	46,219
Auto Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	176,631	185,247
31-60 Days Past Due	951	631
61-90 Days Past Due	116	32
Non-accrual	722	736
Total Past Due	1,789	1,399
Total Loans	178,420	186,646
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,629	2,789
31-60 Days Past Due		14
61-90 Days Past Due		4
Non-accrual	29	38
Total Past Due	29	56
Total Loans	$ 2,658	$ 2,845

Loans Receivable, Net and All51

Loans Receivable, Net and Allowance for Loan Losses - Summary of Primary Segments of ALL (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	$ 9,833	$ 9,342	$ 9,365	$ 9,056
Charge-offs	(642)	(969)	(1,361)	(1,675)
Recoveries	219	243	406	485
Provision	1,100	750	2,100	1,500
Balance, End of period	10,510	9,366	10,510	9,366
Individually evaluated for impairment	304		304		$ 345
Collectively evaluated for impairment	10,206		10,206		9,020
Residential Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	3,769	4,450	3,878	4,426
Charge-offs	(52)	(290)	(95)	(366)
Recoveries	3	5	6	6
Provision	35	(35)	(34)	64
Balance, End of period	3,755	4,130	3,755	4,130
Individually evaluated for impairment	160		160		154
Collectively evaluated for impairment	3,595		3,595		3,724
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	2,319	795	1,758	852
Charge-offs	(14)	(128)	(15)	(218)
Recoveries			2	10
Provision	516	371	1,076	394
Balance, End of period	2,821	1,038	2,821	1,038
Individually evaluated for impairment	12		12		19
Collectively evaluated for impairment	2,809		2,809		1,739
Commercial Real Estate Loans [Member] | Construction Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	33	23	23	13
Provision		7	10	17
Balance, End of period	33	30	33	30
Collectively evaluated for impairment	33		33		23
Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	1,054	965	987	882
Charge-offs	(5)	(1)	(137)	(20)
Recoveries			10
Provision	170	(13)	359	89
Balance, End of period	1,219	951	1,219	951
Collectively evaluated for impairment	1,219		1,219		987
Obligations of States and Political Subdivisions [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	213	234	248	215
Provision	56	10	21	29
Balance, End of period	269	244	269	244
Collectively evaluated for impairment	269		269		248
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	449	441	470	455
Charge-offs	(6)	(6)	(6)	(6)
Recoveries	3	2	5	3
Provision	(45)	8	(68)	(7)
Balance, End of period	401	445	401	445
Individually evaluated for impairment	2		2
Collectively evaluated for impairment	399		399		470
Auto Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	1,962	2,062	1,836	1,880
Charge-offs	(550)	(544)	(1,087)	(1,061)
Recoveries	211	232	381	460
Provision	281	158	774	629
Balance, End of period	1,904	1,908	1,904	1,908
Individually evaluated for impairment	130		130		172
Collectively evaluated for impairment	1,774		1,774		1,664
Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	21	25	21	25
Charge-offs	(15)		(21)	(4)
Recoveries	2	4	2	6
Provision	13	(5)	19	(3)
Balance, End of period	21	24	21	24
Collectively evaluated for impairment	21		21		21
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, Beginning of period	13	347	144	308
Provision	74	249	(57)	288
Balance, End of period	87	$ 596	87	$ 596
Collectively evaluated for impairment	$ 87		$ 87		$ 144

Loans Receivable, Net and All52

Loans Receivable, Net and Allowance for Loan Losses - Summary of Troubled Debt Restructuring Granted (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018USD ($)Contract	Mar. 31, 2017USD ($)Contract	Mar. 31, 2018USD ($)Contract	Mar. 31, 2017USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		3		5
Real Estate Loans [Member] | Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		1	2	3
Pre-Modification Outstanding Recorded Investment		$ 135	$ 243	$ 379
Post-Modification Outstanding Recorded Investment		$ 135	$ 235	$ 379
Real Estate Loans [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 107	$ 132	$ 107	$ 132
Post-Modification Outstanding Recorded Investment	$ 107	$ 132	$ 107	$ 132
Auto Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1		1
Pre-Modification Outstanding Recorded Investment	$ 15		$ 15
Post-Modification Outstanding Recorded Investment	$ 15		$ 15
Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		1		1
Pre-Modification Outstanding Recorded Investment		$ 24		$ 24
Post-Modification Outstanding Recorded Investment		$ 24		$ 24
Troubled Debt Restructurings [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	2	3	4	5
Pre-Modification Outstanding Recorded Investment	$ 122	$ 291	$ 365	$ 535
Post-Modification Outstanding Recorded Investment	$ 122	$ 291	$ 357	$ 535

Deposits - Schedule of Deposits

Deposits - Schedule of Deposits by Major Classifications (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Banking And Thrift [Abstract]
Non-interest bearing demand accounts	$ 152,379	$ 160,125
Interest bearing demand accounts	164,611	208,369
Money market accounts	266,927	253,949
Savings and club accounts	143,715	141,521
Certificates of deposit	511,721	510,897
Total	$ 1,239,353	$ 1,274,861

Net Periodic Benefit Cost-Def54

Net Periodic Benefit Cost-Defined Benefit Plan - Summary of the Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Compensation Related Costs [Abstract]
Service Cost		$ 69		$ 378
Interest Cost	$ 175	208	$ 349	443
Expected return on plan assets	(299)	(348)	(597)	(689)
Amortization of unrecognized loss		23		159
Net periodic benefit cost	$ (124)	$ (48)	$ (248)	$ 291

Net Periodic Benefit Cost-Def55

Net Periodic Benefit Cost-Defined Benefit Plan - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Projected benefit obligation	$ (7,100)
Tax effected	$ 4,727	$ 4,817

Equity Incentive Plan - Additio

Equity Incentive Plan - Additional Information (Detail) - USD ($)	Dec. 06, 2017	Oct. 23, 2017	Mar. 29, 2017	Dec. 13, 2016	Mar. 04, 2016	May 20, 2015	Jul. 22, 2014	Apr. 01, 2013	May 23, 2008	Mar. 31, 2018	Mar. 31, 2017
Compensation Related Costs Disclosure [Line Items]
Stock option granted										0
Option vesting period										5 years
Option expiration period										10 years
Share-based compensation expense										$ 184,000	$ 145,000
Equity Incentive Plan [Member]
Compensation Related Costs Disclosure [Line Items]
Common stock issuance, Grant										2,377,326
2016 Plan [Member]
Compensation Related Costs Disclosure [Line Items]
Common stock issuance, Grant										250,000
Further number of shares, grants										0
Stock Option [Member]
Compensation Related Costs Disclosure [Line Items]
Number of available shares										1,698,090
Restricted Stock [Member]
Compensation Related Costs Disclosure [Line Items]
Number of available shares										679,236
Restricted stock granted	24,278	1,250	3,296	20,675	23,491	21,843	19,880	30,000	590,320
Share-based compensation expense										$ 184,000	$ 145,000
Restricted Stock [Member] | 2013 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										18 months
Restricted Stock [Member] | 2014 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										39 months
Restricted Stock [Member] | 2015 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										40 months
Expected future expense										$ 41,000
Remaining vesting periods										6 months
Restricted Stock [Member] | March 4, 2016 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										43 months
Restricted Stock [Member] | December 13, 2016 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										46 months
Restricted Stock [Member] | March 29, 2017 [Member] | Tranche One [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										42 months
Restricted shares vested, Number of shares										1,296
Restricted Stock [Member] | March 29, 2017 [Member] | Tranche Two [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										18 months
Restricted shares vested, Number of shares										2,000
Restricted Stock [Member] | October 23, 2017 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										23 months
Restricted Stock [Member] | December 6, 2017 [Member]
Compensation Related Costs Disclosure [Line Items]
Restricted shares vesting period										46 months
Restricted Stock [Member] | March 2016 [Member]
Compensation Related Costs Disclosure [Line Items]
Expected future expense										$ 128,000
Remaining vesting periods										1 year 6 months
Restricted Stock [Member] | March 2017 [Member] | Tranche One [Member]
Compensation Related Costs Disclosure [Line Items]
Expected future expense										$ 13,000
Remaining vesting periods										2 years 6 months
Outstanding nonvested restricted stock										(1,296)
Restricted Stock [Member] | March 2017 [Member] | Tranche Two [Member]
Compensation Related Costs Disclosure [Line Items]
Expected future expense										$ 10,000
Remaining vesting periods										6 months
Outstanding nonvested restricted stock										(2,000)
Restricted Stock [Member] | December 2016 [Member]
Compensation Related Costs Disclosure [Line Items]
Expected future expense										$ 223,000
Remaining vesting periods										2 years 6 months
Restricted Stock [Member] | October 2017 [Member]
Compensation Related Costs Disclosure [Line Items]
Expected future expense										$ 15,000
Remaining vesting periods										1 year 6 months
Restricted Stock [Member] | December 2017 [Member]
Compensation Related Costs Disclosure [Line Items]
Expected future expense										$ 352,000
Remaining vesting periods										3 years 6 months
Non Qualified Stock Option [Member]
Compensation Related Costs Disclosure [Line Items]
Stock option granted									1,140,469
Incentive Stock Option [Member]
Compensation Related Costs Disclosure [Line Items]
Stock option granted									317,910

Equity Incentive Plan - Schedul

Equity Incentive Plan - Schedule of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2018	Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Stock Options, Outstanding, September 30, 2017	294,646
Number of Stock Options, Granted	0
Number of Stock Options, Exercised	196,848
Number of Stock Options, Forfeited	0
Number of Stock Options, Outstanding, December 31, 2017	97,798	294,646
Number of Stock Options, Exercisable at December 31, 2017	97,798
Weighted-average Exercise Price, Outstanding, September 30, 2017	$ 12.35
Weighted-average Exercise Price, Granted	0
Weighted-average Exercise Price, Exercised	12.35
Weighted-average Exercise Price, Forfeited	0
Weighted-average Exercise Price, Outstanding, December 31, 2017	12.35	$ 12.35
Weighted-average Exercise Price, Exercisable at December 31, 2017	$ 12.35
Weighted-average Remaining Contractual Term (in years), Outstanding	5 months 1 day	8 months 2 days
Weighted-average Remaining Contractual Term (in years), Granted	0 years
Weighted-average Remaining Contractual Term (in years), Exercised	5 months 1 day
Weighted-average Remaining Contractual Term (in years), Forfeited	0 years
Weighted-average Remaining Contractual Term (in years), Exercisable	5 months 1 day
Aggregate Intrinsic Value, Outstanding, Beginning Balance	$ 987
Aggregate Intrinsic Value, Granted	0
Aggregate Intrinsic Value, Exercised	0
Aggregate Intrinsic Value, Forfeited	0
Aggregate Intrinsic Value, Outstanding, Ending Balance	227	$ 987
Aggregate Intrinsic Value, Exercisable at December 31, 2017	$ 227

Equity Incentive Plan - Sched58

Equity Incentive Plan - Schedule of Restricted Stock Option Activity (Detail) - Restricted Stock [Member]	6 Months Ended
	Mar. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Restricted Stock, Nonvested at September 30, 2017 | shares	34,692
Number of Restricted Stock, Granted | shares	25,528
Number of Restricted Stock, Vested | shares	(1,000)
Number of Restricted Stock, Forfeited | shares	(2,535)
Number of Restricted Stock, Nonvested at December 31, 2017 | shares	56,685
Weighted-average Grant Date Fair Value, Nonvested at September 30, 2017 | $ / shares	$ 14.89
Weighted-average Grant Date Fair Value, Granted | $ / shares	15.86
Weighted-average Grant Date Fair Value, Vested | $ / shares	0
Weighted-average Grant Date Fair Value, Forfeited | $ / shares	14.79
Weighted-average Grant Date Fair Value, Nonvested at December 31, 2017 | $ / shares	$ 15.31

Fair Value Measurement - Schedu

Fair Value Measurement - Schedule of Securities, Derivatives, Other Real Estate Owned and Impaired Loans Measured at Fair Value (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Investment securities available for sale:
Total Securities	$ 377,375	$ 390,452
Derivatives and hedging activities:	2,312	1,215
Foreclosed real estate	1,279	1,424
Impaired loans	13,614	15,231
Mortgage servicing rights	220	232
Fair Value, Measurements, Nonrecurring [Member]
Investment securities available for sale:
Foreclosed real estate	1,279	1,424
Mortgage-Backed Securities [Member]
Investment securities available for sale:
Total Securities	246,708	233,823
Obligations of States and Political Subdivisions [Member]
Investment securities available for sale:
Total Securities	51,362	65,358
U.S. Government Agency Securities [Member]
Investment securities available for sale:
Total Securities	13,108	18,671
Corporate Obligations [Member]
Investment securities available for sale:
Total Securities	44,988	48,742
Other Debt Securities [Member]
Investment securities available for sale:
Total Securities	21,184	23,833
Equity Securities-Financial Services [Member]
Investment securities available for sale:
Total Securities	25	25
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Investment securities available for sale:
Total Securities	25	25
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities-Financial Services [Member]
Investment securities available for sale:
Total Securities	25	25
Significant Other Observable Inputs (Level 2) [Member]
Investment securities available for sale:
Total Securities	369,583	383,203
Derivatives and hedging activities:	2,312	1,215
Significant Other Observable Inputs (Level 2) [Member] | Mortgage-Backed Securities [Member]
Investment securities available for sale:
Total Securities	246,708	233,823
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member]
Investment securities available for sale:
Total Securities	51,362	65,358
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Agency Securities [Member]
Investment securities available for sale:
Total Securities	13,108	18,671
Significant Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]
Investment securities available for sale:
Total Securities	37,221	41,518
Significant Other Observable Inputs (Level 2) [Member] | Other Debt Securities [Member]
Investment securities available for sale:
Total Securities	21,184	23,833
Significant Unobservable Inputs (Level 3) [Member]
Investment securities available for sale:
Total Securities	7,767	7,224
Impaired loans	13,614	15,231
Mortgage servicing rights	220	232
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member]
Investment securities available for sale:
Foreclosed real estate	1,279	1,424
Significant Unobservable Inputs (Level 3) [Member] | Corporate Obligations [Member]
Investment securities available for sale:
Total Securities	$ 7,767	$ 7,224

Fair Value Measurement - Sche60

Fair Value Measurement - Schedule of Changes in Fair Value of Level III Investments (Detail) - Significant Unobservable Inputs (Level 3) [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	$ 7,826	$ 8,238	$ 7,224	$ 7,485
Purchases, sales, issuances, settlements, net		756	500	756
Total unrealized gain (loss):
Included in other comprehensive loss	(59)	(259)	43	494
Ending balance	$ 7,767	$ 8,735	$ 7,767	$ 8,735

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)Loan	Sep. 30, 2017USD ($)Loan
Fair Value Disclosures [Abstract]
Number of impaired loans | Loan	140	164
Impaired loans, carrying value	$ 13,900	$ 15,600
Impaired loans, valuation allowance	304	345
Impaired loans, net fair value	$ 13,600	$ 15,200

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Additional Quantitative Information about Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Input	Prepayment speeds	Prepayment speeds
Fair value input appraisal adjustments	12.20%	15.90%
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	7.00%	11.00%
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	28.00%	30.00%
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Estimate	$ 13,614	$ 15,231
Unobservable Input	Appraisal adjustments	Appraisal adjustments
Fair value input appraisal adjustments	25.30%	24.00%
Impaired Loans [Member] | Appraisal of Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Impaired Loans [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	0.00%	0.00%
Impaired Loans [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	35.00%	57.00%
Foreclosed Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Estimate	$ 1,279	$ 1,424
Unobservable Input	Appraisal adjustments	Appraisal adjustments
Fair value input appraisal adjustments	23.20%	22.00%
Foreclosed Real Estate Owned [Member] | Appraisal of Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Techniques	Appraisal of collateral	Appraisal of collateral
Foreclosed Real Estate Owned [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	20.00%	20.00%
Foreclosed Real Estate Owned [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value input appraisal adjustments	46.00%	46.00%
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Estimate	$ 220	$ 232
Unobservable Input	Discount rate	Discount rate
Fair value input appraisal adjustments	11.00%	11.00%
Mortgage Servicing Rights [Member] | Appraisal of Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Techniques	Discounted cash flow	Discounted cash flow

Fair Value Measurement - Sche63

Fair Value Measurement - Schedule of Estimate of Fair Value Using Methodologies (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Financial assets:
Investment and mortgage backed securities available for sale	$ 377,375	$ 390,452
Loans receivable, net	13,600	15,200
Mortgage servicing rights	220	232
Derivatives	2,312	1,215
Bank-owned life insurance	38,130	37,626
Financial liabilities:
Other borrowings	139,434	174,168
Advances by borrowers for taxes and insurance	12,188	5,163
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	25	25
Significant Other Observable Inputs (Level 2) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	369,583	383,203
Derivatives	2,312	1,215
Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	7,767	7,224
Mortgage servicing rights	220	232
Carrying Value [Member]
Financial assets:
Cash and cash equivalents	34,804	41,683
Certificates of deposit	500	500
Investment and mortgage backed securities available for sale	377,375	390,452
Loans receivable, net	1,291,262	1,236,681
Accrued interest receivable	6,279	6,149
Regulatory stock	17,234	13,832
Mortgage servicing rights	220	232
Derivatives	2,312	1,215
Bank-owned life insurance	38,130	37,626
Financial liabilities:
Deposits	1,239,353	1,274,861
Short-term borrowings	241,345	137,446
Other borrowings	139,434	174,168
Advances by borrowers for taxes and insurance	12,188	5,163
Accrued interest payable	1,077	1,043
Estimated Fair Value [Member]
Financial assets:
Cash and cash equivalents	34,804	41,683
Certificates of deposit	501	505
Investment and mortgage backed securities available for sale	377,375	390,452
Loans receivable, net	1,265,713	1,235,368
Accrued interest receivable	6,279	6,149
Regulatory stock	17,234	13,832
Mortgage servicing rights	220	232
Derivatives	2,312	1,215
Bank-owned life insurance	38,130	37,626
Financial liabilities:
Deposits	1,236,286	1,275,356
Short-term borrowings	241,345	137,446
Other borrowings	138,434	174,107
Advances by borrowers for taxes and insurance	12,188	5,163
Accrued interest payable	1,077	1,043
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Cash and cash equivalents	34,804	41,683
Investment and mortgage backed securities available for sale	25	25
Accrued interest receivable	6,279	6,149
Regulatory stock	17,234	13,832
Bank-owned life insurance	38,130	37,626
Financial liabilities:
Deposits	727,632	763,964
Short-term borrowings	241,345	137,446
Advances by borrowers for taxes and insurance	12,188	5,163
Accrued interest payable	1,077	1,043
Estimated Fair Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets:
Investment and mortgage backed securities available for sale	369,583	383,203
Derivatives	2,312	1,215
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Certificates of deposit	501	505
Investment and mortgage backed securities available for sale	7,767	7,224
Loans receivable, net	1,265,713	1,235,368
Mortgage servicing rights	220	232
Financial liabilities:
Deposits	508,654	511,392
Other borrowings	$ 138,434	$ 174,107

Accumulated Other Comprehensi64

Accumulated Other Comprehensive Loss - Summary of Activity in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			$ 182,727
Total other comprehensive (loss) income	$ (4,633)	$ 5,531	(5,635)	$ (532)
Ending Balance	177,378		177,378
Defined Benefit Pension Plan [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(628)	(5,993)	(628)	(6,083)
Other comprehensive income (loss) before reclassifications		4,714		4,714
Amounts reclassified from accumulated other comprehensive loss, net of tax		13		103
Reclassification of certain income tax effects from accumulated other comprehensive income	(124)		(124)
Total other comprehensive (loss) income	(124)	4,727	(124)	4,817
Ending Balance	(752)	(1,266)	(752)	(1,266)
Unrealized Gains (Losses) on Securities Available for Sale [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(2,215)	(2,801)	(927)	3,952
Other comprehensive income (loss) before reclassifications	(5,100)	781	(6,388)	(5,972)
Amounts reclassified from accumulated other comprehensive loss, net of tax	(57)		(57)
Reclassification of certain income tax effects from accumulated other comprehensive income	(436)		(436)
Total other comprehensive (loss) income	(5,593)	781	(6,881)	(5,972)
Ending Balance	(7,808)	(2,020)	(7,808)	(2,020)
Derivatives [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	1,087	899	801	299
Other comprehensive income (loss) before reclassifications	587	25	888	619
Amounts reclassified from accumulated other comprehensive loss, net of tax	(63)	(2)	(78)	4
Reclassification of certain income tax effects from accumulated other comprehensive income	214		214
Total other comprehensive (loss) income	738	23	1,024	623
Ending Balance	1,825	922	1,825	922
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(1,756)	(7,895)	(754)	(1,832)
Other comprehensive income (loss) before reclassifications	(4,513)	5,520	(5,500)	(639)
Amounts reclassified from accumulated other comprehensive loss, net of tax	(120)	11	(135)	107
Reclassification of certain income tax effects from accumulated other comprehensive income	(346)		(346)
Total other comprehensive (loss) income	(4,979)	5,531	(5,635)	(532)
Ending Balance	$ (6,735)	$ (2,364)	$ (6,735)	$ (2,364)

Accumulated Other Comprehensi65

Accumulated Other Comprehensive Loss - Summary of Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Gain on sale of investments, net	$ 75		$ 75
Income taxes	(529)	$ (203)	(4,622)	$ (603)
Interest expense	(3,912)	(3,075)	(7,520)	(6,093)
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of Available-for-sale Securities [Line Items]
Net of tax	120	(11)	135	(107)
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] | Unrealized Gains (Losses) on Securities Available for Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Gain on sale of investments, net	75		75
Income taxes	(18)		(18)
Net of tax	57		57
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] | Defined Benefit Pension Plan [Member]
Schedule of Available-for-sale Securities [Line Items]
Income taxes		10		56
Net of tax		(13)		(103)
Compensation and employee benefits		(23)		(159)
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] | Derivatives [Member]
Schedule of Available-for-sale Securities [Line Items]
Income taxes	(13)	(3)	(21)	2
Net of tax	63	2	78	(4)
Interest expense	$ 76	$ 5	$ 99	$ (6)

Derivatives And Hedging Activ66

Derivatives And Hedging Activities - Schedule of Fair Value of Derivative Financial Instruments as well as their Classification on Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Derivatives Fair Value [Line Items]
Fair Values of Derivative Instruments	$ 2,312	$ 1,215
Designated as Hedging Instrument [Member] | Interest Rate Products [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Fair Values of Derivative Instruments	$ 2,312	$ 1,215

Derivatives and Hedging Activ67

Derivatives and Hedging Activities - Additional Information (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)Contract	Mar. 31, 2017USD ($)	Mar. 31, 2018USD ($)Contract	Mar. 31, 2017USD ($)	Mar. 31, 2019USD ($)
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Interest income	$ 15,847,000	$ 14,379,000	$ 31,223,000	$ 29,029,000
Increase (decrease) in accrued interest payable			34,000	$ (183,000)
Net liability position of derivatives	0		0
Debt Instrument, collateral amount	0		0
Designated as Hedging Instrument [Member] | Cash Flow Hedges of Interest Rate Risk [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Interest income	$ 76,000		$ 99,000
Designated as Hedging Instrument [Member] | Cash Flow Hedges of Interest Rate Risk [Member] | Scenario, Forecast [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Increase (decrease) in accrued interest payable					$ 0
Designated as Hedging Instrument [Member] | Cash Flow Hedges of Interest Rate Risk [Member] | Interest Rate Swaps [Member] | Variable Rate [Member] | FHLB Advances [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative, number of instruments | Contract	3		3
Derivative, notional principal amount	$ 75,000,000		$ 75,000,000

Derivatives And Hedging Activ68

Derivatives And Hedging Activities - Schedule of Pre-Tax Net Gains (Losses) of Cash flow Hedges (Detail) - Designated as Hedging Instrument [Member] - Cash Flow Hedges of Interest Rate Risk [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments Gain Loss [Line Items]
Loss Recognized in OCI on Derivative (Effective Portion)	$ 738	$ 40
Gain Recognized inOCI on Derivative(Effective Portion)			$ 1,195	$ 1,092
Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	76	5	99
Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)				(6)
Interest Rate Products [Member]
Derivative Instruments Gain Loss [Line Items]
Loss Recognized in OCI on Derivative (Effective Portion)	738	40
Gain Recognized inOCI on Derivative(Effective Portion)			1,195	1,092
Interest Rate Products [Member] | Interest Expense [Member]
Derivative Instruments Gain Loss [Line Items]
Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ 76	$ 5	$ 99
Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)				$ (6)

Contingent Liabilities - Additi

Contingent Liabilities - Additional Information (Detail)	6 Months Ended
	Mar. 31, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
Amount the plaintiff seeks from the bank	$ 1,325,000
Estimate of possible loss to the bank	$ 125,000

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of the Federal Statutory Rate and the Effective Income Tax Rate (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Provision at statutory rate, Amount	$ 676	$ 622	$ 1,271	$ 1,417
Income from bank-owned life insurance, Amount	(60)	(86)	(122)	(176)
Tax-exempt income, Amount	(134)	(216)	(269)	(432)
Low-income housing credits, Amount	52	(74)	(43)	(123)
Tax rate change, Amount			3,780
Other, net, Amount	(5)	(43)	5	(83)
Actual tax expense and effective rate, Amount	$ 529	$ 203	$ 4,622	$ 603
Provision at statutory rate, Percentage of pretax income	24.20%	34.00%	24.20%	34.00%
Income from bank-owned life insurance, Percentage of pretax income	(2.20%)	(4.70%)	(2.30%)	(4.20%)
Tax-exempt income, Percentage of pretax income	(4.80%)	(11.80%)	(5.10%)	(10.40%)
Low-income housing credits, Percentage of pretax income	1.90%	(4.00%)	(0.80%)	(2.90%)
Tax rate change, Percentage of pretax income			72.10%
Other, net, Percentage of pretax income	(0.20%)	(2.30%)	(0.10%)	(2.00%)
Actual tax expense and effective rate, Percentage of pretax income	18.90%	11.20%	88.10%	14.50%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Dec. 31, 2017	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income tax expense increased due to Tax Act	$ 3.8
Cumulative losses period included in positive evidence for evaluation of deferred tax assets		3 years