Territorial Bancorp (TBNK) 10-Q 12 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 31, 2021
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2021
Entity File Number	001-34403
Entity Registrant Name	Territorial Bancorp Inc.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	26-4674701
Entity Address, Address Line One	1132 Bishop Street, Suite 2200
Entity Address, City or Town	Honolulu
Entity Address, State or Province	HI
Entity Address, Postal Zip Code	96813
City Area Code	808
Local Phone Number	946-1400
Title of 12(b) Security	Common stock
Trading Symbol	TBNK
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		9,324,060
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001447051
Amendment Flag	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Cash and cash equivalents	$ 101,386	$ 363,543
Investment securities available for sale, at fair value		3,562
Investment securities held to maturity, at amortized cost (fair value of $623,406 and $262,841 at September 30, 2021 and December 31, 2020, respectively)	621,417	247,642
Loans held for sale	488	2,195
Loans receivable, net	1,303,969	1,406,995
Federal Home Loan Bank stock, at cost	8,173	8,144
Federal Reserve Bank stock, at cost	3,158	3,145
Accrued interest receivable	6,070	6,515
Premises and equipment, net	4,262	4,855
Right-of-use asset, net	13,302	12,333
Bank-owned life insurance	46,214	45,644
Deferred income tax assets, net	3,304	3,382
Prepaid expenses and other assets	5,325	2,844
Total assets	2,117,068	2,110,799
Liabilities:
Deposits	1,664,963	1,659,800
Advances from the Federal Home Loan Bank	141,000	141,000
Securities sold under agreements to repurchase	10,000	10,000
Accounts payable and accrued expenses	29,374	29,221
Lease liability	14,119	13,119
Income taxes payable	2,196	2,161
Advance payments by borrowers for taxes and insurance	3,727	6,790
Total liabilities	1,865,379	1,862,091
Commitments and contingencies
Stockholders' Equity:
Preferred stock, $0.01 par value; authorized 50,000,000 shares, no shares issued or outstanding
Common stock, $0.01 par value; authorized 100,000,000 shares; issued and outstanding 9,342,162 and 9,513,867 shares at September 30, 2021 and December 31, 2020, respectively	93	95
Additional paid-in capital	57,104	61,153
Unearned ESOP shares	(3,548)	(3,915)
Retained earnings	207,007	200,066
Accumulated other comprehensive loss	(8,967)	(8,691)
Total stockholders' equity	251,689	248,708
Total liabilities and stockholders' equity	$ 2,117,068	$ 2,110,799

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Consolidated Balance Sheets (Unaudited)
Investment securities held to maturity, fair value (in dollars)	$ 623,406	$ 262,841
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	100,000,000	100,000,000
Common stock, shares issued	9,342,162	9,513,867
Common stock, shares outstanding	9,342,162	9,513,867

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest income:
Loans	$ 11,836	$ 14,628	$ 37,019	$ 45,310
Investment securities	3,251	2,264	7,470	7,654
Other investments	188	239	647	753
Total interest income	15,275	17,131	45,136	53,717
Interest expense:
Deposits	844	1,897	3,251	7,385
Advances from the Federal Home Loan Bank	522	724	1,595	2,448
Securities sold under agreements to repurchase	46	46	137	137
Total interest expense	1,412	2,667	4,983	9,970
Net interest income	13,863	14,464	40,153	43,747
(Reversal of provision) provision for loan losses	(167)	692	(1,452)	2,304
Net interest income after (reversal of provision) provision for loan losses	14,030	13,772	41,605	41,443
Noninterest income:
Income on bank-owned life insurance	192	204	570	607
Gain on sale of investment securities	403	261	1,840	858
Gain on sale of loans	138	321	584	987
Other	57	63	237	171
Total noninterest income	1,223	1,577	5,189	4,339
Noninterest expense:
Salaries and employee benefits	5,493	5,346	16,576	16,294
Occupancy	1,636	1,701	4,855	4,972
Equipment	1,079	1,155	3,273	3,439
Federal deposit insurance premiums	141	138	424	212
Other general and administrative expenses	1,215	1,046	3,602	2,978
Total noninterest expense	9,564	9,386	28,730	27,895
Income before income taxes	5,689	5,963	18,064	17,887
Income taxes	1,527	1,645	4,831	4,805
Net income	$ 4,162	$ 4,318	$ 13,233	$ 13,082
Basic earnings per share (in dollars per share)	$ 0.46	$ 0.47	$ 1.45	$ 1.43
Diluted earnings per share (in dollars per share)	0.46	0.47	1.44	1.42
Cash dividends declared per common share (in dollars per share)	$ 0.23	$ 0.23	$ 0.69	$ 0.69
Basic weighted-average shares outstanding (in shares)	9,012,398	9,104,079	9,086,447	9,144,463
Diluted weighted-average shares outstanding (in shares)	9,056,569	9,134,089	9,131,069	9,201,882
Service Fees on Loan and Deposit Accounts
Noninterest income:
Service and other fees	$ 433	$ 728	$ 1,958	$ 1,716

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Consolidated Statements of Comprehensive Income (Unaudited)
Net income	$ 4,162	$ 4,318	$ 13,233	$ 13,082
Unrealized (loss) gain on securities, net of tax		(4)	(3)	22
Amount reclassified from other comprehensive income, net of tax			(273)	(221)
Other comprehensive loss, net of tax		(4)	(276)	(199)
Comprehensive income	$ 4,162	$ 4,314	$ 12,957	$ 12,883

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Unearned ESOP Shares	Retained Earnings	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2019	$ 97	$ 65,057	$ (4,404)	$ 190,808	$ (7,668)	$ 243,890
Balance (in shares) at Dec. 31, 2019	9,681,493
Increase (Decrease) in Stockholders' Equity
Net income				13,082		13,082
Other comprehensive loss					(199)	(199)
Cash dividends declared				(6,328)		(6,328)
Share-based compensation		523				523
Share-based compensation (in shares)	18,875
Allocation of ESOP shares		538	367			905
Repurchase of shares of common stock	$ (3)	(6,633)				(6,636)
Repurchase of shares of common stock (in shares)	(268,328)
Exercise of options for common stock	$ 1	1,420				1,421
Exercise of options for common stock (in shares)	81,827
Balance at Sep. 30, 2020	$ 95	60,905	(4,037)	197,562	(7,867)	246,658
Balance (in shares) at Sep. 30, 2020	9,513,867
Balance at Jun. 30, 2020	$ 95	60,606	(4,159)	195,348	(7,863)	244,027
Balance (in shares) at Jun. 30, 2020	9,513,867
Increase (Decrease) in Stockholders' Equity
Net income				4,318		4,318
Other comprehensive loss					(4)	(4)
Cash dividends declared				(2,104)		(2,104)
Share-based compensation		157				157
Allocation of ESOP shares		142	122			264
Balance at Sep. 30, 2020	$ 95	60,905	(4,037)	197,562	(7,867)	246,658
Balance (in shares) at Sep. 30, 2020	9,513,867
Balance at Dec. 31, 2020	$ 95	61,153	(3,915)	200,066	(8,691)	248,708
Balance (in shares) at Dec. 31, 2020	9,513,867
Increase (Decrease) in Stockholders' Equity
Net income				13,233		13,233
Other comprehensive loss					(276)	(276)
Cash dividends declared				(6,292)		(6,292)
Share-based compensation		241				241
Share-based compensation (in shares)	20,437
Allocation of ESOP shares		575	367			942
Repurchase of shares of common stock	$ (2)	(4,865)				(4,867)
Repurchase of shares of common stock (in shares)	(192,142)
Balance at Sep. 30, 2021	$ 93	57,104	(3,548)	207,007	(8,967)	251,689
Balance (in shares) at Sep. 30, 2021	9,342,162
Balance at Jun. 30, 2021	$ 94	58,860	(3,670)	204,928	(8,967)	251,245
Balance (in shares) at Jun. 30, 2021	9,421,560
Increase (Decrease) in Stockholders' Equity
Net income				4,162		4,162
Other comprehensive loss					0
Cash dividends declared				(2,083)		(2,083)
Share-based compensation		36				36
Allocation of ESOP shares		188	122			310
Repurchase of shares of common stock	$ (1)	(1,980)				(1,981)
Repurchase of shares of common stock (in shares)	(79,398)
Balance at Sep. 30, 2021	$ 93	$ 57,104	$ (3,548)	$ 207,007	$ (8,967)	$ 251,689
Balance (in shares) at Sep. 30, 2021	9,342,162

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Consolidated Statements of Stockholders' Equity, Share Data
Cash dividends declared per common share (in dollars per share)	$ 0.23	$ 0.23	$ 0.69	$ 0.69
Common Stock
Consolidated Statements of Stockholders' Equity, Share Data
Allocation of ESOP shares, shares	12,233	12,233	36,700	36,699

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income	$ 13,233	$ 13,082
Adjustments to reconcile net income to net cash from operating activities:
(Reversal of provision) provision for loan losses	(1,452)	2,304
Depreciation and amortization	870	899
Deferred income tax expense (benefit)	179	(599)
Amortization of fees, discounts, and premiums, net	(311)	(228)
Amortization of right-of-use asset	2,316	2,238
Origination of loans held for sale	(24,304)	(22,605)
Proceeds from sales of loans held for sale	26,595	22,822
Gain on sale of loans, net	(584)	(987)
Gain on sale of investment securities available for sale	(339)	(290)
Gain on sale of investment securities held to maturity	(1,501)	(568)
Net loss (gain) on disposal of premises and equipment	2	(4)
ESOP expense	942	905
Share-based compensation expense	241	523
Decrease (increase) in accrued interest receivable	445	(1,805)
Net increase in bank-owned life insurance	(570)	(607)
Net increase in prepaid expenses and other assets	(2,481)	(96)
Net increase in accounts payable and accrued expenses	814	2,080
Net decrease in lease liability	(2,285)	(2,146)
Net decrease in advance payments by borrowers for taxes and insurance	(3,063)	(2,856)
Net increase in income taxes payable	35	106
Net cash from operating activities	8,782	12,168
Cash flows from investing activities:
Purchases of investment securities held to maturity	(474,439)
Principal repayments on investment securities held to maturity	78,547	71,118
Principal repayments on investment securities available for sale	198	1,013
Proceeds from sale of investment securities held to maturity	23,570	10,429
Proceeds from sale of investment securities available for sale	3,330	3,668
Principal repayments on loans receivable, net of loan originations	104,832	90,780
Purchases of Federal Home Loan Bank stock	(29)	(21)
Proceeds from redemption of Federal Home Loan Bank stock		600
Purchases of Federal Reserve Bank stock	(13)	(17)
Purchases of premises and equipment	(279)	(1,466)
Proceeds from disposals of premises and equipment		4
Net cash from investing activities	(264,283)	176,108
Cash flows from financing activities:
Net increase in deposits	5,163	30,773
Repayments of advances from the Federal Home Loan Bank		(15,000)
Proceeds from securities sold under agreements to repurchase		5,000
Repayments of securities sold under agreements to repurchase		(5,000)
Purchases of Fed Funds		10
Sales of Fed Funds		(10)
Repurchases of common stock	(4,547)	(5,000)
Cash dividends paid	(7,272)	(6,357)
Net cash from financing activities	(6,656)	4,416
Net (decrease) increase in cash and cash equivalents	(262,157)	192,692
Cash and cash equivalents at beginning of the period	363,543	44,806
Cash and cash equivalents at end of the period	101,386	237,498
Cash paid for:
Interest on deposits and borrowings	4,966	10,268
Income taxes	4,617	6,208
Supplemental disclosure of noncash investing and financing activities:
Company stock acquired through stock swap and net settlement transactions		1,421
Company stock repurchased through stock swap and net settlement transactions	320	1,636
Loans securitized into investment securities		9,431
Establishment of right-of-use asset, net of incentives	3,285	4,033
Establishment of lease liability	$ 3,285	$ 4,093

Organization

Organization	9 Months Ended
	Sep. 30, 2021
Organization
Organization	(1) Organization ​ Territorial Bancorp Inc. (the Company) is a Maryland corporation and is the holding company for Territorial Savings Bank (the Bank). Territorial Savings Bank is a Hawaii state-chartered bank headquartered in Honolulu, Hawaii and is a member of the Federal Reserve System. Territorial Savings Bank has an inactive subsidiary, Territorial Financial Services, Inc. During the three months ended September 30, 2021, another inactive subsidiary, Territorial Real Estate Co., was dissolved.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Basis of Presentation
Basis of Presentation	(2) Basis of Presentation ​ The accompanying unaudited interim condensed consolidated financial statements of Territorial Bancorp Inc. have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These unaudited interim condensed consolidated financial statements and notes should be read in conjunction with the Company’s consolidated financial statements and notes thereto filed as part of the Annual Report on Form 10-K for the year ended December 31, 2020. In the opinion of management, all adjustments necessary for a fair presentation have been made and consist only of normal recurring adjustments. Interim results of operations are not necessarily indicative of results to be expected for the year.

Recently Issued Accounting Pron

Recently Issued Accounting Pronouncements	9 Months Ended
	Sep. 30, 2021
Recently Issued Accounting Pronouncements
Recently Issued Accounting Pronouncements	(3) Recently Issued Accounting Pronouncements ​ In June 2016, the Financial Accounting Standards Board (FASB) amended various sections of the FASB Accounting Standards Codification (ASC) related to the accounting for credit losses on financial instruments. The amendment changes the threshold for recognizing losses from a “probable” to an “expected” model. The new model is referred to as the current expected credit loss model and applies to loans, leases, held-to-maturity investments, loan commitments and financial guarantees. The amendment requires the measurement of all expected credit losses for financial assets as of the reporting date (including historical experience, current conditions and reasonable and supportable forecasts) and enhanced disclosures that will help financial statement users understand the estimates and judgments used in estimating credit losses and evaluating the credit quality of an organization’s portfolio. The amendment is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. In November 2019, the FASB issued an update that delays the effective date of the amendment for smaller reporting companies, as defined by the Securities and Exchange Commission, to fiscal years beginning after December 15, 2022. The Company is a smaller reporting company. The Company will apply the amendment’s provisions as a cumulative-effect adjustment to retained earnings at the beginning of the first period the amendment is effective. The Company has formed a team that is working on an implementation plan to adopt the amendment. The implementation plan will include developing policies, procedures and internal controls over the model. The Company is also working with a software vendor to measure expected losses required by the amendment. The Company is currently evaluating the effects that the adoption of this amendment will have on its consolidated financial statements and expects that the portfolio composition and economic conditions at the time of adoption will influence the accounting adjustment made at the time the amendment is adopted. ​ The Coronavirus Aid, Relief, and Economic Security (CARES) Act was passed by Congress and signed into law on March 27, 2020. The CARES Act provides relief to financial institutions from categorizing eligible loan modifications as troubled debt restructurings over the remaining life of the modified loan. Eligible loan modifications under the CARES Act must be related to the COVID-19 pandemic and the borrower must not have been more than 30 days past due as of December 31, 2019. Loan modifications under the CARES Act must be executed during the period from March 1, 2020 to the earlier of December 31, 2020 or 60 days after the end of the national emergency. December 21, 2020, legislation extended the troubled debt restructuring relief provisions of the CARES Act to January 1, 2022. Banking regulators issued similar guidance, which also clarified that a COVID-19 loan modification should not be considered a troubled debt restructuring if the borrower was not more than 30 days past due on payments at the time the loan modification program was implemented and the modification is considered short-term (not to exceed six months) ​

Cash and Cash Equivalents

Cash and Cash Equivalents	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents
Cash and Cash Equivalents	(4) Cash and Cash Equivalents ​ The table below presents the balances of cash and cash equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, (Dollars in thousands) 2021 2020 Cash and due from banks ​ $ 11,361 ​ $ 14,355 ​ ​ Interest-earning deposits in other banks ​ 90,025 ​ 349,188 ​ ​ Cash and cash equivalents ​ $ 101,386 ​ $ 363,543 ​ ​ ​ Interest-earning deposits in other banks consist primarily of deposits at the Federal Reserve Bank of San Francisco.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2021
Investment Securities.
Investment Securities	(5) Investment Securities ​ The amortized cost and fair values of investment securities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross Unrealized ​ Estimated (Dollars in thousands) Cost Gains Losses Fair Value September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 621,417 ​ $ 7,682 $ (5,693) ​ $ 623,406 ​ Total ​ $ 621,417 ​ $ 7,682 $ (5,693) ​ $ 623,406 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 3,185 ​ $ 377 $ — ​ $ 3,562 ​ Total ​ $ 3,185 ​ $ 377 $ — ​ $ 3,562 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 247,642 ​ $ 15,200 $ (1) ​ $ 262,841 ​ Total ​ $ 247,642 ​ $ 15,200 $ (1) ​ $ 262,841 ​ ​ The amortized cost and estimated fair value of investment securities by maturity date at September 30, 2021 are shown below. Incorporated in the maturity schedule are mortgage-backed securities, which are allocated using the contractual maturity as a basis. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Estimated (Dollars in thousands) Cost Fair Value Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ Due within 5 years ​ $ 17 ​ $ 17 ​ Due after 5 years through 10 years ​ 30 ​ 30 ​ Due after 10 years ​ 621,370 ​ 623,359 ​ Total ​ $ 621,417 ​ $ 623,406 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Realized gains and losses and the proceeds from sales of held-to-maturity and available-for-sale securities are shown in the table below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (Dollars in thousands) 2021 2020 2021 2020 Proceeds from sales ​ $ 7,539 ​ $ 5,737 ​ $ 26,900 ​ $ 14,097 ​ Gross gains ​ 403 ​ 261 ​ 1,840 ​ 858 ​ Gross losses ​ — ​ — ​ — ​ — ​ ​ During the nine months ended September 30, 2021 and 2020, the Company sold $22.1 million and $9.9 million, respectively, of held-to-maturity mortgage-backed securities and recorded gains of $1.5 million and $568,000, respectively. The sale of the mortgage-backed securities, for which the Company had already collected a substantial portion of the outstanding purchased principal (at least 85%), were in accordance with the Investments – Debt and Equity Securities topic of the FASB ASC and do not taint management’s assertion of its intent to hold the remaining securities in the held-to-maturity portfolio to maturity. ​ During the nine months ended September 30, 2021 and 2020, the Company sold $3.0 million and $3.4 million, respectively, of available-for-sale mortgage-backed securities and recorded gains of $339,000 and $290,000, respectively. ​ Investment securities with amortized costs of $148.4 million and $192.7 million at September 30, 2021 and December 31, 2020, respectively, were pledged to secure deposits made by state and local governments, securities sold under agreements to repurchase and transaction clearing accounts. ​ Provided below is a summary of investment securities which were in an unrealized loss position at September 30, 2021 and December 31, 2020. The Company does not intend to sell held-to-maturity securities until such time as the value recovers or the securities mature and it is not more likely than not that the Company will be required to sell the securities prior to recovery of value or the securities mature. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less Than 12 Months 12 Months or Longer Total Unrealized Unrealized Number of Unrealized Description of securities Fair Value Losses Fair Value Losses Securities Fair Value Losses (Dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 439,788 ​ $ (5,692) ​ $ 42 ​ $ (1) 32 ​ $ 439,830 ​ $ (5,693) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 678 ​ $ (1) ​ $ 4 ​ $ — 6 ​ $ 682 ​ $ (1) ​ ​ Mortgage-Backed Securities. The unrealized losses on the Company’s investment in mortgage-backed securities were caused by increases in market interest rates subsequent to purchase. All of the mortgage-backed securities are guaranteed by Freddie Mac or Fannie Mae, which are U.S. government-sponsored enterprises, or Ginnie Mae, which is a U.S. government agency. Since the decline in market value is attributable to changes in interest rates and not credit quality, and the Company does not intend to sell these investments until maturity and it is not more likely than not that the Company will be required to sell such investments prior to recovery of its cost basis, the Company does not consider these investments to be other-than-temporarily impaired as of September 30, 2021 and December 31, 2020. ​ During the nine months ended September 30, 2020, the Company securitized fixed-rate first mortgage loans with a book value of $9.4 million into Freddie Mac mortgage-backed securities to increase liquidity. The securitization transaction increased investment securities and lowered loans receivable. The securitization transaction was accounted for by recording the mortgage-backed securities at a fair value of million. A net gain of was recognized on the securitization transaction and recorded in gain on sale of loans in the Consolidated Statements of Income. There were

Loans Receivable and Allowance

Loans Receivable and Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2021
Loans Receivable and Allowance for Loan Losses
Loans Receivable and Allowance for Loan Losses	(6) Loans Receivable and Allowance for Loan Losses ​ The components of loans receivable are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ (Dollars in thousands) 2021 2020 Real estate loans: ​ ​ ​ ​ ​ ​ ​ First mortgages: ​ ​ ​ ​ ​ ​ ​ One- to four-family residential ​ $ 1,266,739 ​ $ 1,366,507 ​ Multi-family residential ​ 6,577 ​ 7,245 ​ Construction, commercial and other ​ 19,281 ​ 19,074 ​ Home equity loans and lines of credit ​ 7,091 ​ 9,376 ​ Total real estate loans ​ 1,299,688 ​ 1,402,202 ​ Other loans: ​ ​ ​ ​ ​ ​ ​ Loans on deposit accounts ​ 290 ​ 235 ​ Consumer and other loans ​ 8,293 ​ 10,086 ​ Total other loans ​ 8,583 ​ 10,321 ​ Less: ​ ​ ​ ​ ​ ​ ​ Net unearned fees and discounts ​ (1,503) ​ (1,266) ​ Allowance for loan losses ​ (2,799) ​ (4,262) ​ Total unearned fees, discounts and allowance for loan losses ​ (4,302) ​ (5,528) ​ Loans receivable, net ​ $ 1,303,969 ​ $ 1,406,995 ​ ​ The table below presents the activity in the allowance for loan losses by portfolio segment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Construction, Home Commercial Equity and Other Loans and Residential Mortgage Lines of Consumer (Dollars in thousands) Mortgage Loans Credit and Other Unallocated Totals Three months ended September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 2,021 ​ $ 434 ​ $ 1 ​ $ 133 ​ $ 380 ​ $ 2,969 ​ (Reversal of provision) provision for loan losses ​ (132) ​ 11 ​ — ​ (19) ​ (27) ​ (167) ​ ​ ​ 1,889 ​ 445 ​ 1 ​ 114 ​ 353 ​ 2,802 ​ Charge-offs ​ — ​ — ​ — ​ (3) ​ — ​ (3) ​ Recoveries ​ — ​ — ​ — ​ — ​ — ​ — ​ Net charge-offs ​ — ​ — ​ — ​ (3) ​ — ​ (3) ​ Balance, end of period ​ $ 1,889 ​ $ 445 ​ $ 1 ​ $ 111 ​ $ 353 ​ $ 2,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 3,102 ​ $ 406 ​ $ 1 ​ $ 146 ​ $ 607 ​ $ 4,262 ​ (Reversal of provision) provision for loan losses ​ (1,213) ​ 39 ​ — ​ (24) ​ (254) ​ (1,452) ​ ​ ​ 1,889 ​ 445 ​ 1 ​ 122 ​ 353 ​ 2,810 ​ Charge-offs ​ — ​ — ​ — ​ (13) ​ — ​ (13) ​ Recoveries ​ — ​ — ​ — ​ 2 ​ — ​ 2 ​ Net charge-offs ​ — ​ — ​ — ​ (11) ​ — ​ (11) ​ Balance, end of period ​ $ 1,889 ​ $ 445 ​ $ 1 ​ $ 111 ​ $ 353 ​ $ 2,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Construction, Home Commercial Equity and Other Loans and Residential Mortgage Lines of Consumer (Dollars in thousands) Mortgage Loans Credit and Other Unallocated Totals Three months ended September 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 3,020 ​ $ 459 ​ $ 1 ​ $ 197 ​ $ 579 ​ $ 4,256 ​ Provision (reversal of provision) for loan losses ​ 988 ​ (2) ​ — ​ (21) ​ (273) ​ 692 ​ ​ ​ 4,008 ​ 457 ​ 1 ​ 176 ​ 306 ​ 4,948 ​ Charge-offs ​ — ​ — ​ — ​ (6) ​ — ​ (6) ​ Recoveries ​ — ​ — ​ — ​ — ​ — ​ — ​ Net charge-offs ​ — ​ — ​ — ​ (6) ​ — ​ (6) ​ Balance, end of period ​ $ 4,008 ​ $ 457 ​ $ 1 ​ $ 170 ​ $ 306 ​ $ 4,942 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 1,741 ​ $ 511 ​ $ 1 ​ $ 54 ​ $ 405 ​ $ 2,712 ​ Provision (reversal of provision) for loan losses ​ 2,267 ​ (54) ​ (10) ​ 200 ​ (99) ​ 2,304 ​ ​ ​ 4,008 ​ 457 ​ (9) ​ 254 ​ 306 ​ 5,016 ​ Charge-offs ​ — ​ — ​ — ​ (86) ​ — ​ (86) ​ Recoveries ​ — ​ — ​ 10 ​ 2 ​ — ​ 12 ​ Net recoveries (charge-offs) ​ — ​ — ​ 10 ​ (84) ​ — ​ (74) ​ Balance, end of period ​ $ 4,008 ​ $ 457 ​ $ 1 ​ $ 170 ​ $ 306 ​ $ 4,942 ​ ​ Management considers the allowance for loan losses at September 30, 2021 to be at an appropriate level to provide for probable losses that can be reasonably estimated based on general and specific conditions at that date. While the Company uses the best information it has available to make evaluations, future adjustments to the allowance may be necessary if conditions differ substantially from the information used in making the evaluations. To the extent actual outcomes differ from the estimates, additional provisions for credit losses may be required that would reduce future earnings. The table below presents the balance in the allowance for loan losses and the recorded investment in loans, net of unearned fees and discounts, by portfolio segment and based on impairment method: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Construction, Home Commercial Equity and Other Loans and Residential Mortgage Lines of Consumer (Dollars in thousands) Mortgage Loans Credit and Other Unallocated Totals September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for loan losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending allowance balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ Collectively evaluated for impairment ​ 1,889 ​ 445 ​ 1 ​ 111 ​ 353 ​ 2,799 ​ Total ending allowance balance ​ $ 1,889 ​ $ 445 ​ $ 1 ​ $ 111 ​ $ 353 ​ $ 2,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending loan balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ 4,785 ​ $ — ​ $ 19 ​ $ — ​ $ — ​ $ 4,804 ​ Collectively evaluated for impairment ​ 1,267,080 ​ 19,223 ​ 7,077 ​ 8,584 ​ — ​ 1,301,964 ​ Total ending loan balance ​ $ 1,271,865 ​ $ 19,223 ​ $ 7,096 ​ $ 8,584 ​ $ — ​ $ 1,306,768 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for loan losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending allowance balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ Collectively evaluated for impairment ​ 3,102 ​ 406 ​ 1 ​ 146 ​ 607 ​ 4,262 ​ Total ending allowance balance ​ $ 3,102 ​ $ 406 ​ $ 1 ​ $ 146 ​ $ 607 ​ $ 4,262 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending loan balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ 4,947 ​ $ — ​ $ 23 ​ $ — ​ $ — ​ $ 4,970 ​ Collectively evaluated for impairment ​ 1,367,576 ​ 19,024 ​ 9,353 ​ 10,334 ​ — ​ 1,406,287 ​ Total ending loan balance ​ $ 1,372,523 ​ $ 19,024 ​ $ 9,376 ​ $ 10,334 ​ $ — ​ $ 1,411,257 ​ ​ The table below presents the balance of impaired loans individually evaluated for impairment by class of loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Unpaid Recorded Principal (Dollars in thousands) Investment Balance September 30, 2021: ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 4,785 ​ $ 5,358 ​ Home equity loans and lines of credit ​ 19 ​ 31 ​ Total ​ $ 4,804 ​ $ 5,389 ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 4,947 ​ $ 5,425 ​ Home equity loans and lines of credit ​ ​ 23 ​ ​ 32 ​ Total ​ $ 4,970 ​ $ 5,457 ​ ​ The table below presents the average recorded investment and interest income recognized on impaired loans by class of loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended For the Nine Months Ended September 30, September 30, Average Interest Average Interest Recorded Income Recorded Income (Dollars in thousands) Investment Recognized Investment Recognized 2021: ​ ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 4,816 ​ $ 8 ​ $ 4,866 ​ $ 28 ​ Home equity loans and lines of credit ​ 20 ​ — ​ 21 ​ — ​ Total ​ $ 4,836 ​ $ 8 ​ $ 4,887 ​ $ 28 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 2,745 ​ $ 8 ​ $ 2,770 ​ $ 25 ​ Home equity loans and lines of credit ​ ​ 24 ​ — ​ 25 ​ — ​ Total ​ $ 2,769 ​ $ 8 ​ $ 2,795 ​ $ 25 ​ ​ ​ There were no loans individually evaluated for impairment with a related allowance for loan loss as of September 30, 2021 or December 31, 2020. Loans individually evaluated for impairment do not have an allocated allowance for loan loss because they are written down to fair value at the time of impairment. ​ The Company had 12 nonaccrual loans with a book value of $4.2 million as of September 30, 2021 and a book value of $4.4 million as of December 31, 2020. The Company collected interest on nonaccrual loans of during the nine months ended September 30, 2021 and 2020, respectively, but due to accounting and regulatory requirements, the Company recorded the interest payments as a reduction of principal. The Company would have recognized additional interest income of during the nine months ended September 30, 2021 and 2020, respectively, had the loans been accruing interest. The Company did ​ The table below presents the aging of loans and accrual status by class of loans, net of unearned fees and discounts. Loans with a formal loan payment deferral plan in place are not considered contractually past due or delinquent if the borrower is in compliance with the loan payment deferral plan. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans 90 Days or More 30 - 59 60 - 89 90 Days or Past Due Days Past Days Past More Total Past Loans Not Total Nonaccrual and Still (Dollars in thousands) Due Due Past Due Due Past Due Loans Loans Accruing September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ — ​ $ — ​ $ 99 ​ $ 99 ​ $ 1,265,201 ​ $ 1,265,300 ​ $ 4,230 ​ $ — ​ Multi-family residential mortgages ​ — ​ — ​ — ​ — ​ 6,565 ​ 6,565 ​ — ​ — ​ Construction, commercial and other mortgages ​ — ​ — ​ — ​ — ​ 19,223 ​ 19,223 ​ — ​ — ​ Home equity loans and lines of credit ​ — ​ — ​ — ​ — ​ 7,096 ​ 7,096 ​ 19 ​ — ​ Loans on deposit accounts ​ — ​ — ​ — ​ — ​ 290 ​ 290 ​ — ​ — ​ Consumer and other ​ 5 ​ 23 ​ — ​ 28 ​ 8,266 ​ 8,294 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 5 ​ $ 23 ​ $ 99 ​ $ 127 ​ $ 1,306,641 ​ $ 1,306,768 ​ $ 4,249 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 376 ​ $ 152 ​ $ 240 ​ $ 768 ​ $ 1,364,527 ​ $ 1,365,295 ​ $ 4,382 ​ $ — ​ Multi-family residential mortgages ​ — ​ — ​ — ​ — ​ 7,228 ​ 7,228 ​ — ​ — ​ Construction, commercial and other mortgages ​ — ​ — ​ — ​ — ​ 19,024 ​ 19,024 ​ — ​ — ​ Home equity loans and lines of credit ​ — ​ 23 ​ — ​ 23 ​ 9,353 ​ 9,376 ​ 23 ​ — ​ Loans on deposit accounts ​ — ​ — ​ — ​ — ​ 235 ​ 235 ​ — ​ — ​ Consumer and other ​ 1 ​ — ​ — ​ 1 ​ 10,098 ​ 10,099 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 377 ​ $ 175 ​ $ 240 ​ $ 792 ​ $ 1,410,465 ​ $ 1,411,257 ​ $ 4,405 ​ $ — ​ ​ ​ The Company primarily uses the aging of loans and accrual status to monitor the credit quality of its loan portfolio. When a mortgage loan becomes seriously delinquent ( 90 days or more contractually past due), it displays weaknesses that may result in a loss. As a loan becomes more delinquent, the likelihood of the borrower repaying the loan decreases and the loan becomes more collateral-dependent. A mortgage loan becomes collateral-dependent when the proceeds for repayment can be expected to come only from the sale or operation of the collateral and not from borrower repayments. Generally, appraisals are obtained after a loan becomes collateral-dependent or is four months delinquent. The carrying value of collateral-dependent loans is adjusted to the fair value of the collateral less selling costs. Any commercial real estate, commercial, construction or equity loan that has a loan balance in excess of a specified amount is also periodically reviewed to determine whether the loan exhibits any weaknesses and is performing in accordance with its contractual terms. ​ There were no loans modified in a troubled debt restructuring during the nine months ended September 30, 2021 or 2020. There were new troubled debt restructurings within the nine months ended September 30, 2021 or 2020 that subsequently defaulted. Loan modifications under the CARES Act and the Interagency Statements issued by bank regulators in 2020 are discussed below. ​ The table below summarizes outstanding troubled debt restructurings by class of loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Accrual Number of Nonaccrual ​ (Dollars in thousands) Loans Status Loans Status Total September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ 3 ​ $ 554 ​ ​ 2 ​ $ 425 ​ $ 979 Total ​ 3 ​ $ 554 ​ ​ 2 ​ $ 425 ​ $ 979 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ 3 ​ $ 565 ​ ​ 2 ​ $ 467 ​ $ 1,032 Total ​ 3 ​ $ 565 ​ ​ 2 ​ $ 467 ​ $ 1,032 ​ There were no delinquent troubled debt restructurings as of September 30, 2021 or December 31, 2020. Restructurings include deferrals of interest and/or principal payments and temporary or permanent reductions in interest rates due to the financial difficulties of the borrowers. At September 30, 2021, we had ​ The CARES Act provides relief to financial institutions from categorizing eligible loan modifications as troubled debt restructurings over the remaining life of the modified loan. Eligible loan modifications under the CARES Act must be related to the COVID-19 pandemic and the borrower must not have been more than 30 days past due as of December 31, 2019. Loan modifications under the CARES Act must be executed during the period from March 1, 2020 to the earlier of 60 days after the end of the national emergency or January 1, 2022. Banking regulators issued similar guidance, which also clarified that a COVID-19 related loan modification should not be considered a troubled debt restructuring if the borrower was not more than 30 days past due on payments at the time the loan modification program was implemented and the modification is considered short-term (not to exceed six months). The Company uses the provisions of the CARES Act and the Interagency Statements to account for the eligible loans receiving modifications. ​ The Company has granted loan payment deferrals to borrowers who have been affected by the COVID-19 pandemic. At September 30, 2021, the Company had outstanding loan payment deferrals on $90.4 million of loans, which represented 6.9% of total loans receivable. ​ The table below summarizes loans in the loan payment deferral program by class of loan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ (Dollars in thousands) ​ Loans in the Loan Payment Deferral Program ​ Percent of Total Loans One- to- four family residential mortgage ​ $ 86,538 ​ 6.6 % Non-residential mortgage ​ $ 3,857 ​ 0.3 % Total ​ $ 90,395 ​ 6.9 % ​ The loans on which the Company has granted loan payment deferrals are included in the ALLL calculation. However, loans performing under a loan payment deferral agreement are not considered contractually past due and are excluded from the past due statistics above. ​ The ratio of the current loan balance to the current tax-assessed value of the property securing the mortgage loans in the payment deferral program averaged 55.9% at September 30, 2021. At September 30, 2021, one- to four-family residential mortgage loans represented 97.1% of the Company’s total loan portfolio balance with a ratio of the current loan balance to the current tax assessed value of the property securing these loans averaging 45.2%. All of the Company’s residential mortgage loans are secured by real estate in Hawaii. ​ As of September 30, 2021, of the $86.5 million total one- to four-family mortgage loans in the loan payment deferral program, $66.5 million, or 76.9% , had resumed making full principal and interest payments. The interest on these loans that accrued during the deferral period will be repaid over subsequent years. total mortgage loans in the loan payment deferral program were making interest-only payments. There are ​ As of September 30, 2021, $3.4 million of the $3.9 million commercial mortgage, commercial and industrial and home equity lines of credit in the loan payment deferral program had resumed making full principal and interest payments. A ​ Since the beginning of the year, we have not seen a significant increase in loan delinquencies, significant changes in deposits or significant drawdowns on any lines of credit. Loan delinquencies do not include loans requesting payment deferral because of the COVID-19 pandemic. We do not have any commercial loans to hotels, businesses in the transportation industry, restaurants or retail establishments. ​ The Company had no real estate owned as of September 30, 2021 or December 31, 2020. There was a in the process of foreclosure at September 30, 2021. There were ​ Nearly all of our real estate loans are collateralized by real estate located in the State of Hawaii. Loan-to-value ratios on these real estate loans generally do not exceed ​ During the nine months ended September 30, 2021 and 2020, the Company sold mortgage loans held for sale with principal balances of $26.2 million and $22.3 million, respectively, and recognized gains of $584,000 and $610,000 , respectively. The Company had ​ During the nine months ended September 30, 2020, the Company securitized fixed-rate first mortgage loans with a book value of $9.4 million and received mortgage-backed securities with a fair market value of $9.8 million. The Company retained the servicing of these loans and recorded mortgage servicing assets with a fair market value of was recognized on the transaction. There were no securitization transactions in the nine months ended September 30, 2021. ​ The Company serviced loans for others with principal balances of $44.7 million at September 30, 2021 and $56.7 million at December 31, 2020. Of these amounts, million of loan balances relate to securitizations for which the Company continues to hold the related mortgage-backed securities at September 30, 2021 and December 31, 2020, respectively. The amount of contractually specified servicing fees earned for the nine months ended September 30, 2021 and 2020 was , respectively. The amount of contractually specified servicing fees earned for the three months ended September 30, 2021 and 2020 was , respectively. The fees are reported in service and other fees in the Consolidated Statements of Income.

Securities Sold Under Agreement

Securities Sold Under Agreements to Repurchase	9 Months Ended
	Sep. 30, 2021
Securities Sold Under Agreements to Repurchase
Securities Sold Under Agreements to Repurchase	(7) Securities Sold Under Agreements to Repurchase ​ Securities sold under agreements to repurchase are treated as financings and the obligations to repurchase the identical securities sold are reflected as a liability with the securities collateralizing the agreements classified as an asset. Securities sold under agreements to repurchase are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 December 31, 2020 Weighted Weighted Repurchase Average Repurchase Average (Dollars in thousands) Liability Rate Liability Rate Maturing: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Over 3 years to 4 years ​ $ 10,000 1.81 % $ 5,000 1.88 % Over 4 years to 5 years ​ — — ​ 5,000 1.73 % Total ​ $ 10,000 1.81 % $ 10,000 1.81 % ​ Below is a summary comparing the carrying value and fair value of securities pledged to secure repurchase agreements, the repurchase liability, and the amount at risk at September 30, 2021. The amount at risk is the greater of the carrying value or fair value over the repurchase liability and refers to the potential loss to the Company if the secured lender fails to return the security at the maturity date of the agreement. All the agreements to repurchase are with JP Morgan Securities and the securities pledged are mortgage-backed securities issued and guaranteed by U.S. government-sponsored enterprises. The repurchase liability cannot exceed of the fair value of securities pledged. In the event of a decline in the fair value of securities pledged to less than the required amount due to market conditions or principal repayments, the Company is obligated to pledge additional securities or other suitable collateral to cure the deficiency. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Carrying Fair Average Value of Value of Repurchase Amount Months to (Dollars in thousands) Securities Securities Liability at Risk Maturity Maturing: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Over 90 days ​ $ 11,990 ​ $ 12,402 ​ $ 10,000 ​ $ 2,402 39 ​ ​

Offsetting of Financial Liabili

Offsetting of Financial Liabilities	9 Months Ended
	Sep. 30, 2021
Offsetting of Financial Liabilities
Offsetting of Financial Liabilities	(8) Offsetting of Financial Liabilities ​ The following table presents our securities sold under agreements to repurchase that are subject to a right of offset in the event of default. See Note 7, Securities Sold Under Agreements to Repurchase, for additional information. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net Amount of Gross Amount Not Offset in the Gross Amount Gross Amount Liabilities Balance Sheet of Recognized Offset in the Presented in the Financial Cash Collateral (Dollars in thousands) Liabilities Balance Sheet Balance Sheet Instruments ​ Pledged Net Amount September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities sold under agreements to repurchase ​ $ 10,000 ​ $ — ​ $ 10,000 ​ $ 10,000 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities sold under agreements to repurchase ​ $ 10,000 ​ $ — ​ $ 10,000 ​ $ 10,000 ​ $ — ​ $ — ​

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2021
Employee Benefit Plans
Employee Benefit Plans	(9) Employee Benefit Plans ​ The Company has a noncontributory defined benefit pension plan (Pension Plan) that covers most employees with at least one year of service. Effective December 31, 2008, under approved changes to the Pension Plan, there were no further accruals of benefits for any participants and benefits will not increase with any additional years of service. Net periodic benefit cost, subsequent to December 31, 2008, has not been significant and is not disclosed in the table below. ​ The Company also sponsors a Supplemental Employee Retirement Plan (SERP), a noncontributory supplemental retirement benefit plan, which covers certain current and former employees of the Company for amounts in addition to those provided under the Pension Plan. ​ The components of net periodic benefit cost were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SERP SERP Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2021 2020 2021 2020 Net periodic benefit cost for the period: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost ​ $ 2 ​ $ 22 ​ $ 7 ​ $ 66 ​ Interest cost ​ 45 ​ 43 ​ 135 ​ 130 ​ Expected return on plan assets ​ — ​ — ​ — ​ — ​ Amortization of prior service cost ​ — ​ — ​ — ​ — ​ Recognized actuarial loss ​ — ​ — ​ — ​ — ​ Recognized curtailment loss ​ — ​ — ​ — ​ — ​ Net periodic benefit cost ​ $ 47 ​ $ 65 ​ $ 142 ​ $ 196 ​ ​ The service cost component of net periodic benefit cost is included with salaries and employee benefits in the consolidated statements of income. The other components of net periodic benefit cost are included in other general and administrative expenses.

Employee Stock Ownership Plan

Employee Stock Ownership Plan	9 Months Ended
	Sep. 30, 2021
Employee Stock Ownership Plan
Employee Stock Ownership Plan
Employee Stock Ownership Plan	(10) Employee Stock Ownership Plan ​ Effective January 1, 2009, Territorial Savings Bank adopted an Employee Stock Ownership Plan (ESOP) for eligible employees. The ESOP borrowed , of the total number of shares issued by the Company in its initial public offering. The shares were acquired at a price of ​ The loan is secured by the shares purchased with the loan proceeds and will be repaid by the ESOP over the 20-year term of the loan with funds from Territorial Savings Bank’s contributions to the ESOP and dividends payable on the shares. The interest rate on the ESOP loan is an adjustable rate equal to the prime rate, as published in The Wall Street Journal . The interest rate adjusts annually and will be the prime rate on the first business day of the calendar year. ​ Shares purchased by the ESOP are held by a trustee in an unallocated suspense account, and shares are released annually from the suspense account on a pro-rata basis as principal and interest payments are made by the ESOP to the Company. The trustee allocates the shares released among participants on the basis of each participant’s proportional share of compensation relative to all participants. As shares are committed to be released from the suspense account, Territorial Savings Bank reports compensation expense based on the average fair value of shares released with a corresponding credit to stockholders’ equity. The shares committed to be released are considered outstanding for earnings per share computations. Compensation expense recognized for the three months ended September 30, 2021 and 2020 amounted to , respectively. ​ Shares held by the ESOP trust were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, 2021 2020 Allocated shares ​ 528,636 ​ 507,304 ​ Unearned shares ​ 354,764 ​ 391,464 ​ Total ESOP shares ​ 883,400 ​ 898,768 ​ Fair value of unearned shares, in thousands ​ $ 9,004 ​ $ 9,407 ​ ​ The ESOP restoration plan is a nonqualified plan that provides supplemental benefits to certain executives who are prevented from receiving the full benefits contemplated by the ESOP’s benefit formula. The supplemental cash payments consist of payments representing shares that cannot be allocated to the participants under the ESOP due to IRS limitations imposed on tax-qualified plans. We accrue for these benefits over the period during which employees provide services to earn these benefits. For the three months ended September 30, 2021 and 2020 we accrued and $5,000, respectively, for the ESOP restoration plan. For the nine months ended September 30, 2021 and 2020, we accrued $94,000 and $79,000 , respectively, for the ESOP restoration plan.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2021
2010 Equity Incentive Plan
Share-Based Compensation
Share-Based Compensation	(11) Share-Based Compensation ​ The shareholders of Territorial Bancorp Inc. have adopted the 2010 Equity Incentive Plan and the 2019 Equity Incentive Plan. These plans provide for the award of stock options and restricted stock to key officers and directors. In accordance with the Compensation – Stock Compensation topic of the FASB ASC, the cost of the equity incentive plans is based on the fair value of the awards on the grant date. The fair value of restricted stock is based on the closing price of the Company’s stock on the grant date. The fair value of stock options is estimated using a Black-Scholes option pricing model using assumptions for dividend yield, stock price volatility, risk-free interest rate and option term. These assumptions are based on our judgments regarding future events, are subjective in nature, and cannot be determined with precision. The cost of the awards will be recognized on a straight-line basis over the three , five - or six- year vesting period during which participants are required to provide services in exchange for the awards. No new awards can be made under the 2010 Equity Plan, but awards previously made can continue to vest. There are 146,347 shares remaining available for new awards under the 2019 Equity Plan. ​ The Company recognized compensation expense, measured as the fair value of the share-based award on the date of grant, on a straight-line basis over the vesting period. Share-based compensation is recorded in the Consolidated Statements of Income as a component of salaries and employee benefits with a corresponding increase in stockholders’ equity. The table below presents information on compensation expense and the related tax benefit for all share-based awards: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended September 30, September 30, (In thousands) 2021 2020 2021 2020 Compensation expense ​ $ 36 ​ $ 157 ​ $ 241 ​ $ 523 ​ Income tax benefit ​ 10 ​ 43 ​ 66 ​ 143 ​ ​ Stock Options ​ The table below presents the stock option activity for the nine months ended September 30, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Aggregate ​ ​ ​ ​ Average ​ Remaining ​ Intrinsic ​ ​ ​ ​ Exercise ​ Contractual ​ Value ​ ​ Options ​ Price ​ Life (years) ​ (in thousands) Options outstanding at December 31, 2020 3,085 ​ $ 23.62 1.67 ​ $ 1 ​ Granted — ​ — — ​ — ​ Exercised — ​ — — ​ — ​ Forfeited — ​ — — ​ — ​ Expired — ​ — — ​ — ​ Options outstanding at September 30, 2021 ​ 3,085 ​ $ 23.62 0.92 ​ $ 5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options outstanding at December 31, 2019 116,409 ​ $ 17.53 0.72 ​ $ 1,562 ​ Granted — ​ — — ​ — ​ Exercised 81,827 ​ 17.36 — ​ 725 ​ Forfeited — ​ — — ​ — ​ Expired 31,497 ​ — — ​ — ​ Options outstanding at September 30, 2020 3,085 ​ $ 23.62 1.92 ​ $ (11) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options vested and exercisable at September 30, 2021 3,085 ​ $ 23.62 0.92 ​ $ 5 ​ ​ The following summarizes certain stock option activity of the Company: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended For the Nine Months Ended September 30, September 30, (In thousands) 2021 2020 2021 2020 Intrinsic value of stock options exercised ​ $ — ​ $ — ​ $ — ​ $ 725 ​ Proceeds received from stock options exercised ​ — ​ — ​ — ​ 1,421 ​ Tax benefits realized from stock options exercised ​ — ​ — ​ — ​ 158 ​ Total fair value of stock options that vested ​ — ​ — ​ — ​ — ​ ​ As of September 30, 2021, the Company had no unrecognized compensation costs related to the stock option plans. ​ Restricted Stock ​ Restricted stock awards are accounted for as fixed grants using the fair value of the Company’s stock at the time of grant. Unvested restricted stock may not be disposed of or transferred during the vesting period. Restricted stock carries the right to receive dividends, although dividends attributable to restricted stock are retained by the Company until the shares vest, at which time they are paid to the award recipient. Unvested restricted stock that is time-based contain nonforfeitable dividend rights. Accrued dividends on restricted stock that do not vest based on performance or market conditions are forfeited. ​ The table below presents the time-based restricted stock activity: ​ ​ ​ ​ ​ ​ ​ ​ Weighted Time-Based Average Grant Restricted Date Fair Stock Value Unvested at December 31, 2020 23,695 ​ $ 24.24 ​ Granted 10,849 ​ 26.67 ​ Vested 11,336 ​ 25.81 ​ Forfeited — ​ — ​ Unvested at September 30, 2021 23,208 ​ $ 24.61 ​ ​ ​ ​ ​ ​ ​ ​ Unvested at December 31, 2019 20,249 ​ $ 28.78 ​ Granted 13,444 ​ 21.05 ​ Vested 9,998 ​ 29.16 ​ Forfeited — ​ — ​ Unvested at September 30, 2020 23,695 ​ $ 24.24 ​ ​ During the nine months ended September 30, 2021, the Company issued 10,849 shares of restricted stock to certain members of executive management under the 2019 Equity Incentive Plan. The fair value of the restricted stock is based on the value of the Company’s stock on the date of grant. Restricted stock will vest over three years from the date of the grant. ​ As of September 30, 2021, the Company had $418,000 of unrecognized compensation costs related to restricted stock. ​ The table below presents the performance-based restricted stock units (PRSUs) that will vest on a performance condition: ​ ​ ​ ​ ​ ​ ​ Performance- ​ ​ ​ ​ Based Restricted ​ ​ ​ Stock Units Weighted ​ ​ Based on a ​ Average Grant ​ ​ Performance ​ Date Fair Condition Value Unvested at December 31, 2020 40,585 ​ $ 25.83 Granted 13,016 ​ 26.67 Vested 7,473 ​ 30.73 Forfeited 4,545 ​ 30.73 Unvested at September 30, 2021 41,583 ​ $ 24.68 ​ ​ ​ ​ ​ ​ Unvested at December 31, 2019 35,976 ​ $ 29.16 Granted 16,129 ​ 21.05 Vested 7,680 ​ 29.53 Forfeited 3,840 ​ 29.53 Unvested at September 30, 2020 40,585 ​ $ 25.83 ​ During the nine months ended September 30, 2021, the Company issued 13,016 PRSUs to certain members of executive management under the 2019 Equity Incentive Plan. These PRSUs will vest three years after they are granted after our Compensation Committee determines whether a performance condition that compares the Company’s return on average equity to the SNL Bank Index is achieved. Depending on the Company’s performance, the actual number of these PRSUs that are issued at the end of the vesting period can vary between 0% to 150% of the target award. For the PRSUs, an estimate is made of the number of shares expected to vest based on the probability that the performance criteria will be achieved to determine the amount of compensation expense to be recognized. This estimate is re-evaluated quarterly and total compensation expense is adjusted for any change in the current period. ​ The fair value of these PRSUs is based on the fair value of the Company’s stock on the date of grant. As of September 30, 2021 , the Company had $99,000 of unrecognized compensation costs related to these PRSUs. Performance will be measured over a three-year performance period and will be cliff vested. ​ The table below presents the PRSUs that will vest on a market condition: ​ ​ ​ ​ ​ ​ ​ ​ ​ Performance- ​ ​ ​ ​ ​ Based Restricted ​ Monte Carlo ​ ​ Stock Units ​ Valuation of ​ ​ Based on a ​ the Company's Market Condition Stock Unvested at December 31, 2020 10,147 ​ $ 24.69 Granted 3,254 ​ ​ 25.94 Vested 1,628 ​ 28.32 Forfeited 1,377 ​ 28.32 Unvested at September 30, 2021 10,396 ​ $ 24.03 ​ ​ ​ ​ ​ ​ Unvested at December 31, 2019 8,994 ​ $ 25.74 Granted 4,032 ​ 22.16 Vested 1,197 ​ 24.44 Forfeited 1,682 ​ 22.44 Unvested at September 30, 2020 10,147 ​ $ 24.69 ​ During the nine months ended September 30, 2021, the Company also issued 3,254 PRSUs to certain members of executive management under the 2019 Equity Incentive Plan. These PRSUs will vest three years after they are granted after our Compensation Committee determines whether a market condition that compares the Company’s total stock return to the SNL Bank Index is achieved. The number of shares that will be expensed will not be adjusted for performance. The fair value of these PRSUs is based on a Monte Carlo valuation of the Company’s stock on the date of grant. The assumptions which were used in the Monte Carlo valuation of the PRSUs are: ​ Grant date: April 5, 2021 Performance period: January 1, 2021 to December 31, 2023 2.74 year risk-free rate on grant date: 0.32% December 31, 2020 closing price: $24.03 Closing stock price on the date of grant: $26.77 Annualized volatility (based on 2.74 year historical volatility as of the grant date): 38.5% ​ As of September 30, 2021 , the Company had $85,000 of unrecognized compensation costs related to the PRSUs that are based on a market condition. Performance will be measured over a three-year performance period and will be cliff vested.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share
Earnings Per Share	(12) Earnings Per Share ​ Holders of unvested restricted stock accrue dividends at the same rate as common shareholders and they both share equally in undistributed earnings. Unvested restricted stock awards that are time-based contain nonforfeitable rights to dividends or dividend equivalents and are considered to be participating securities in the earnings per share computation using the two-class method. Under the two-class method, earnings are allocated to common shareholders and participating securities according to their respective rights to earnings. Unvested restricted stock awards that vest based on performance or market conditions are not considered to be participating securities in the earnings per share calculation because accrued dividends on shares that do not vest are forfeited. ​ The table below presents the information used to compute basic and diluted earnings per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended September 30, September 30, ​ (Dollars in thousands, except per share data) 2021 2020 2021 2020 Net income ​ $ 4,162 ​ $ 4,318 ​ $ 13,233 ​ $ 13,082 ​ ​ Income allocated to participating securities ​ ​ (23) ​ ​ (23) ​ ​ (47) ​ ​ (47) ​ ​ Net income available to common shareholders ​ $ 4,139 ​ $ 4,295 ​ $ 13,186 ​ $ 13,035 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average number of shares used in: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share ​ 9,012,398 ​ 9,104,079 ​ 9,086,447 ​ 9,144,463 ​ ​ Dilutive common stock equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options and restricted stock units ​ 44,171 ​ 30,010 ​ 44,622 ​ 57,419 ​ ​ Diluted earnings per share ​ 9,056,569 ​ 9,134,089 ​ 9,131,069 ​ 9,201,882 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income per common share, basic ​ $ 0.46 ​ $ 0.47 ​ $ 1.45 ​ $ 1.43 ​ ​ Net income per common share, diluted ​ $ 0.46 ​ $ 0.47 ​ $ 1.44 ​ $ 1.42 ​ ​ ​

Other Comprehensive Income and

Other Comprehensive Income and Loss	9 Months Ended
	Sep. 30, 2021
Other Comprehensive Income and Loss
Other Comprehensive Income and Loss	(13) Other Comprehensive Income and Loss ​ The table below presents the changes in the components of accumulated other comprehensive income and loss, net of taxes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unfunded Unrealized Pension (Gain)/Loss on (Dollars in thousands) Liability Securities Total Three months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,967 ​ $ — ​ $ 8,967 ​ Net current period other comprehensive loss ​ — ​ — ​ — ​ Balances at end of period ​ $ 8,967 ​ $ — ​ $ 8,967 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,178 ​ $ (315) ​ $ 7,863 ​ Other comprehensive loss, net of taxes ​ — ​ 4 ​ 4 ​ Net current period other comprehensive loss ​ — ​ 4 ​ 4 ​ Balances at end of period ​ $ 8,178 ​ $ (311) ​ $ 7,867 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,967 ​ $ (276) ​ $ 8,691 ​ Other comprehensive loss, net of taxes ​ — ​ 3 ​ 3 ​ Amounts reclassified from other comprehensive income, net of taxes ​ — ​ 273 ​ 273 ​ Net current period other comprehensive loss ​ — ​ 276 ​ 276 ​ Balances at end of period ​ $ 8,967 ​ $ — ​ $ 8,967 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,178 ​ $ (510) ​ $ 7,668 ​ Other comprehensive income, net of taxes ​ ​ — ​ ​ (22) ​ ​ (22) ​ Amounts reclassified from other comprehensive income, net of taxes ​ — ​ 221 ​ 221 ​ Net current period other comprehensive loss ​ — ​ 199 ​ 199 ​ Balances at end of period ​ $ 8,178 ​ $ (311) ​ $ 7,867 ​ ​ The table below presents the tax effect on each component of accumulated other comprehensive income and loss: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, 2021 2020 Pretax After Tax Pretax After Tax (Dollars in thousands) Amount Tax Amount Amount Tax Amount Unrealized loss on securities ​ $ — ​ $ — ​ $ — ​ $ 5 ​ $ (1) ​ $ 4 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ 2021 2020 ​ Pretax After Tax Pretax After Tax (Dollars in thousands) Amount Tax Amount Amount Tax Amount Unrealized loss (gain) on securities ​ $ 4 ​ $ (1) ​ $ 3 ​ $ (30) ​ $ 8 ​ $ (22) ​ Amount reclassified from other comprehensive income ​ ​ 373 ​ ​ (100) ​ ​ 273 ​ ​ 301 ​ ​ (80) ​ ​ 221 ​ Total ​ $ 377 ​ $ (101) ​ $ 276 ​ $ 271 ​ $ (72) ​ $ 199 ​ ​

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2021
Revenue Recognition
Revenue Recognition	(14) Revenue Recognition ​ The Company’s contracts with customers are generally short-term in nature, with cycles of one year or less. These can range from an immediate term for services such as wire transfers, foreign currency exchanges and cashier’s check purchases, to several days for services such as processing annuity and mutual fund sales. Some contracts may be gof an ongoing nature, such as providing deposit account services, including ATM access, check processing, account analysis and check ordering. However, provision of an assessable service and payment for such service is usually concurrent or closely timed. Contracts related to financial instruments, such as loans, investments and debt, are excluded from the scope of this reporting requirement. ​ After analyzing the Company’s revenue sources, including the amount of revenue received, the timing of services rendered and the timing of payment for these services, the Company has determined that the rendering of services and the payment for such services are generally closely matched. Any differences are not material to the Company’s consolidated financial statements. Accordingly, the Company generally records income when payment for services is received. ​ Revenue from contracts with customers is reported in service and other fees in other noninterest income in the consolidated statements of income. The table below reconciles the revenue from contracts with customers and other revenue reported in those line items: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service and ​ ​ ​ ​ (Dollars in thousands) Other Fees Other Total Three months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 399 ​ $ 30 ​ $ 429 Other revenue ​ ​ 34 ​ ​ 27 ​ ​ 61 Total ​ $ 433 ​ $ 57 ​ $ 490 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 715 ​ $ 35 ​ $ 750 Other revenue ​ ​ 13 ​ ​ 28 ​ ​ 41 Total ​ $ 728 ​ $ 63 ​ $ 791 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 1,855 ​ $ 154 ​ $ 2,009 Other revenue ​ ​ 103 ​ ​ 83 ​ ​ 186 Total ​ $ 1,958 ​ $ 237 ​ $ 2,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 1,639 ​ $ 88 ​ $ 1,727 Other revenue ​ ​ 77 ​ ​ 83 ​ ​ 160 Total ​ $ 1,716 ​ $ 171 ​ $ 1,887 ​

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases
Leases	​ (15) Leases ​ The table below presents lease costs and other information for the periods indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended ​ September 30, September 30, (Dollars in thousands) 2021 2020 2021 2020 Lease costs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating lease costs ​ $ 843 ​ $ 878 ​ $ 2,552 ​ $ 2,509 ​ Short-term lease costs ​ 15 ​ 5 ​ 32 ​ 17 ​ Variable lease costs ​ 31 ​ 38 ​ 113 ​ 115 ​ Total lease costs ​ $ 889 ​ $ 921 ​ $ 2,697 ​ $ 2,641 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in measurement of lease liabilities ​ $ 836 ​ $ 808 ​ $ 2,520 ​ $ 2,414 ​ ROU assets obtained in exchange for new operating lease liabilities ​ $ 444 ​ $ 2,247 ​ $ 3,285 ​ $ 4,033 ​ ​ At September 30, 2021, future minimum rental commitments under noncancellable operating leases are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ $ 801 ​ ​ ​ ​ ​ ​ 2022 ​ 3,048 ​ ​ ​ ​ ​ ​ 2023 ​ 2,697 ​ ​ ​ ​ ​ ​ 2024 ​ 2,441 ​ ​ ​ ​ ​ ​ 2025 ​ 1,740 ​ ​ ​ ​ ​ ​ Thereafter ​ 4,264 ​ ​ ​ ​ ​ ​ Total ​ ​ 14,991 ​ ​ ​ ​ ​ ​ Less present value discount ​ ​ (872) ​ ​ ​ ​ ​ ​ Present value of leases ​ $ 14,119 ​ ​ ​ ​ ​ ​ ​ The table below presents other lease related information: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ September 30, ​ ​ ​ 2021 ​ 2020 ​ Weighted-average remaining lease term (years) ​ 5.95 ​ ​ 6.00 ​ ​ Weighted-average discount rate ​ ​ 2.18 % ​ ​ 2.45 % ​ ​

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2021
Fair Value
Fair Value	(16) Fair Value ​ In accordance with the Fair Value Measurements and Disclosures topic of the FASB ASC, the Company groups its financial assets and liabilities measured or disclosed at fair value into three levels based on the markets in which the financial assets and liabilities are traded and the reliability of the assumptions used to determine fair value as follows: ​ ● Level 1 — Valuation is based upon quoted prices (unadjusted) for identical assets or liabilities traded in active markets. A quoted price in an active market provides the most reliable evidence of fair value and shall be used to measure fair value whenever available. ​ ● Level 2 — Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market. ​ ● Level 3 — Valuation is generated from model-based techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect management’s own estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of discounted cash flow models and similar techniques that require the use of significant judgment or estimation. ​ In accordance with the Fair Value Measurements and Disclosures topic, the Company bases its fair values on the price that it would expect to receive if an asset were sold or the price that it would expect to pay to transfer a liability in an orderly transaction between market participants at the measurement date. Also as required, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs when developing fair value measurements. ​ The Company uses fair value measurements to determine fair value disclosures. Investment securities held for sale and derivatives are recorded at fair value on a recurring basis. From time to time, the Company may be required to record other financial assets at fair value on a nonrecurring basis, such as loans held for sale, impaired loans and investments, and mortgage servicing assets. These nonrecurring fair value adjustments typically involve application of the lower of cost or fair value accounting or write-downs of individual assets. ​ Investment Securities Available for Sale. ​ Interest Rate Contracts. The Company may enter into interest rate lock commitments with borrowers on loans intended to be sold. To manage interest rate risk on the lock commitments, the Company may also enter into forward loan sale commitments. The interest rate lock commitments and forward loan sale commitments are treated as derivatives and are recorded at their fair value determined by referring to prices quoted in the secondary market for similar contracts. The fair value inputs are considered Level 2 inputs. Interest rate contracts that are classified as assets are included with prepaid expenses and other assets on the Consolidated Balance Sheet while interest rate contracts that are classified as liabilities are included with accounts payable and accrued expenses. ​ The estimated fair values of the Company’s financial instruments are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ ​ Fair Value Measurements Using (Dollars in thousands) Amount Fair Value Level 1 Level 2 Level 3 September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 101,386 ​ $ 101,386 ​ $ 101,386 ​ $ — ​ $ — ​ Investment securities held to maturity ​ 621,417 ​ ​ 623,406 ​ ​ — ​ ​ 623,406 ​ ​ — ​ Loans held for sale ​ 488 ​ ​ 489 ​ ​ — ​ ​ 489 ​ ​ — ​ Loans receivable, net ​ 1,303,969 ​ ​ 1,362,554 ​ ​ — ​ ​ — ​ ​ 1,362,554 ​ FHLB stock ​ 8,173 ​ ​ 8,173 ​ ​ — ​ ​ 8,173 ​ ​ — ​ FRB stock ​ ​ 3,158 ​ ​ 3,158 ​ ​ — ​ ​ 3,158 ​ ​ — ​ Accrued interest receivable ​ 6,070 ​ ​ 6,070 ​ ​ 18 ​ ​ 1,159 ​ ​ 4,893 ​ Interest rate contracts ​ 209 ​ ​ 209 ​ ​ — ​ ​ 209 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deposits ​ 1,664,963 ​ ​ 1,666,163 ​ ​ — ​ ​ 1,429,153 ​ ​ 237,010 ​ Advances from the Federal Home Loan Bank ​ 141,000 ​ ​ 143,498 ​ ​ — ​ ​ 143,498 ​ ​ — ​ Securities sold under agreements to repurchase ​ 10,000 ​ ​ 10,279 ​ ​ — ​ ​ 10,279 ​ ​ — ​ Accrued interest payable ​ 52 ​ ​ 52 ​ ​ — ​ ​ 50 ​ ​ 2 ​ Interest rate contracts ​ 209 ​ ​ 209 ​ ​ — ​ ​ 209 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 363,543 ​ $ 363,543 ​ $ 363,543 ​ $ — ​ $ — ​ Investment securities available for sale ​ ​ 3,562 ​ ​ 3,562 ​ ​ — ​ ​ 3,562 ​ ​ — ​ Investment securities held to maturity ​ 247,642 ​ ​ 262,841 ​ ​ — ​ ​ 262,841 ​ ​ — ​ Loans held for sale ​ 2,195 ​ ​ 2,274 ​ ​ — ​ ​ 2,274 ​ ​ — ​ Loans receivable, net ​ 1,406,995 ​ ​ 1,433,489 ​ ​ — ​ ​ — ​ ​ 1,433,489 ​ FHLB stock ​ 8,144 ​ ​ 8,144 ​ ​ — ​ ​ 8,144 ​ ​ — ​ FRB stock ​ ​ 3,145 ​ ​ 3,145 ​ ​ — ​ ​ 3,145 ​ ​ — ​ Accrued interest receivable ​ 6,515 ​ ​ 6,515 ​ ​ 16 ​ ​ 627 ​ ​ 5,872 ​ Interest rate contracts ​ 38 ​ ​ 38 ​ ​ — ​ ​ 38 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deposits ​ 1,659,800 ​ ​ 1,663,226 ​ ​ — ​ ​ 1,338,022 ​ ​ 325,204 ​ Advances from the Federal Home Loan Bank ​ 141,000 ​ ​ 145,441 ​ ​ — ​ ​ 145,441 ​ ​ — ​ Securities sold under agreements to repurchase ​ 10,000 ​ ​ 10,466 ​ ​ — ​ ​ 10,466 ​ ​ — ​ Accrued interest payable ​ 35 ​ ​ 35 ​ ​ — ​ ​ 33 ​ ​ 2 ​ Interest rate contracts ​ 38 ​ ​ 38 ​ ​ — ​ ​ 38 ​ ​ — ​ ​ At September 30, 2021 and December 31, 2020, neither the commitment fees received on commitments to extend credit nor the fair value thereof was material to the consolidated financial statements of the Company. ​ The table below presents the balance of assets and liabilities measured at fair value on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) Level 1 Level 2 Level 3 Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate contracts — assets ​ $ — ​ $ 209 ​ $ — ​ $ 209 ​ Interest rate contracts — liabilities ​ — ​ (209) ​ — ​ (209) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate contracts — assets ​ $ — ​ $ 38 ​ $ — ​ $ 38 ​ Interest rate contracts — liabilities ​ — ​ (38) ​ — ​ (38) ​ Investment securities available for sale ​ — ​ 3,562 ​ — ​ 3,562 ​ ​ The table below presents the balance of assets measured at fair value on a nonrecurring basis as of December 31, 2020 and the related losses for the year ended December 31, 2020. There were assets measured at fair value on a nonrecurring basis as of September 30, 2021. There were ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value ​ ​ (Dollars in thousands) Adjustment Date ​ Level 1 Level 2 Level 3 Total ​ Total Losses ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mortgage servicing assets ​ 12/31/2020 ​ $ — ​ $ — ​ $ 407 ​ $ 407 ​ $ (73) ​ ​ Mortgage servicing assets are valued using a discounted cash flow model. Assumptions used in the model include mortgage prepayment speeds, discount rates and cost of servicing. Losses on mortgage servicing assets are included in service and other fees in the consolidated statements of income. ​ The table below presents the significant unobservable inputs for Level 3 nonrecurring fair value measurements. The discount rates and prepayment speeds have been weighted by the relative notional amounts. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unobservable Range (Dollars in thousands) Fair Value Valuation Technique Input (Weighted Average) December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mortgage servicing assets ​ $ 407 Discounted cash flow Discount rate ​ ​ 9.25% - 11.25% (10.25%) ​ ​ ​ ​ ​ ​ ​ Prepayment speed (CPR) ​ 10.42 - 19.61 (13.57) ​ ​ ​ ​ ​ ​ ​ Annual cost to service (per loan, in dollars) ​ $ 75 ​ ​

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events
Subsequent Events	(17) Subsequent Events ​ On October 28, 2021, the Board of Directors of Territorial Bancorp Inc. declared a quarterly cash dividend of $0.23 per share of common stock. The dividend is expected to be paid on November 24, 2021 to stockholders of record as of November 11, 2021. ​ On March 12, 2021, the Company filed with the SEC a Current Report on Form 8-K, disclosing that the Company had received a subpoena from the SEC in respect to the Company’s earnings per share calculations. On October 1, 2021, the Company received a letter from the SEC’s Division of Enforcement indicating that it had concluded the investigation of the Company with no enforcement action recommended. ​ On October 28, 2021, the Board of Directors of Territorial Bancorp Inc. announced the completion of its tenth repurchase program. Under this repurchase program, the Company was authorized to repurchase up to

Cash and Cash Equivalents (Tabl

Cash and Cash Equivalents (Tables)	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents
Schedule of balances of cash and cash equivalents	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, (Dollars in thousands) 2021 2020 Cash and due from banks ​ $ 11,361 ​ $ 14,355 ​ ​ Interest-earning deposits in other banks ​ 90,025 ​ 349,188 ​ ​ Cash and cash equivalents ​ $ 101,386 ​ $ 363,543 ​ ​

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Investment Securities.
Schedule of amortized cost and fair values of investment securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross Unrealized ​ Estimated (Dollars in thousands) Cost Gains Losses Fair Value September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 621,417 ​ $ 7,682 $ (5,693) ​ $ 623,406 ​ Total ​ $ 621,417 ​ $ 7,682 $ (5,693) ​ $ 623,406 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 3,185 ​ $ 377 $ — ​ $ 3,562 ​ Total ​ $ 3,185 ​ $ 377 $ — ​ $ 3,562 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 247,642 ​ $ 15,200 $ (1) ​ $ 262,841 ​ Total ​ $ 247,642 ​ $ 15,200 $ (1) ​ $ 262,841 ​ ​
Schedule of amortized cost and estimated fair value of investment securities by maturity	​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Estimated (Dollars in thousands) Cost Fair Value Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ Due within 5 years ​ $ 17 ​ $ 17 ​ Due after 5 years through 10 years ​ 30 ​ 30 ​ Due after 10 years ​ 621,370 ​ 623,359 ​ Total ​ $ 621,417 ​ $ 623,406 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of realized gains and losses and proceeds from sales of securities held to maturity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (Dollars in thousands) 2021 2020 2021 2020 Proceeds from sales ​ $ 7,539 ​ $ 5,737 ​ $ 26,900 ​ $ 14,097 ​ Gross gains ​ 403 ​ 261 ​ 1,840 ​ 858 ​ Gross losses ​ — ​ — ​ — ​ — ​
Summary of investment securities in an unrealized loss position	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less Than 12 Months 12 Months or Longer Total Unrealized Unrealized Number of Unrealized Description of securities Fair Value Losses Fair Value Losses Securities Fair Value Losses (Dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 439,788 ​ $ (5,692) ​ $ 42 ​ $ (1) 32 ​ $ 439,830 ​ $ (5,693) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Held-to-maturity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government-sponsored mortgage-backed securities ​ $ 678 ​ $ (1) ​ $ 4 ​ $ — 6 ​ $ 682 ​ $ (1) ​ ​

Loans Receivable and Allowanc_2

Loans Receivable and Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2021
Loans Receivable and Allowance for Loan Losses
Schedule of components of loans receivable	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ (Dollars in thousands) 2021 2020 Real estate loans: ​ ​ ​ ​ ​ ​ ​ First mortgages: ​ ​ ​ ​ ​ ​ ​ One- to four-family residential ​ $ 1,266,739 ​ $ 1,366,507 ​ Multi-family residential ​ 6,577 ​ 7,245 ​ Construction, commercial and other ​ 19,281 ​ 19,074 ​ Home equity loans and lines of credit ​ 7,091 ​ 9,376 ​ Total real estate loans ​ 1,299,688 ​ 1,402,202 ​ Other loans: ​ ​ ​ ​ ​ ​ ​ Loans on deposit accounts ​ 290 ​ 235 ​ Consumer and other loans ​ 8,293 ​ 10,086 ​ Total other loans ​ 8,583 ​ 10,321 ​ Less: ​ ​ ​ ​ ​ ​ ​ Net unearned fees and discounts ​ (1,503) ​ (1,266) ​ Allowance for loan losses ​ (2,799) ​ (4,262) ​ Total unearned fees, discounts and allowance for loan losses ​ (4,302) ​ (5,528) ​ Loans receivable, net ​ $ 1,303,969 ​ $ 1,406,995 ​
Schedule of activity in allowance for loan losses on loans receivable and by portfolio segment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Construction, Home Commercial Equity and Other Loans and Residential Mortgage Lines of Consumer (Dollars in thousands) Mortgage Loans Credit and Other Unallocated Totals Three months ended September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 2,021 ​ $ 434 ​ $ 1 ​ $ 133 ​ $ 380 ​ $ 2,969 ​ (Reversal of provision) provision for loan losses ​ (132) ​ 11 ​ — ​ (19) ​ (27) ​ (167) ​ ​ ​ 1,889 ​ 445 ​ 1 ​ 114 ​ 353 ​ 2,802 ​ Charge-offs ​ — ​ — ​ — ​ (3) ​ — ​ (3) ​ Recoveries ​ — ​ — ​ — ​ — ​ — ​ — ​ Net charge-offs ​ — ​ — ​ — ​ (3) ​ — ​ (3) ​ Balance, end of period ​ $ 1,889 ​ $ 445 ​ $ 1 ​ $ 111 ​ $ 353 ​ $ 2,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 3,102 ​ $ 406 ​ $ 1 ​ $ 146 ​ $ 607 ​ $ 4,262 ​ (Reversal of provision) provision for loan losses ​ (1,213) ​ 39 ​ — ​ (24) ​ (254) ​ (1,452) ​ ​ ​ 1,889 ​ 445 ​ 1 ​ 122 ​ 353 ​ 2,810 ​ Charge-offs ​ — ​ — ​ — ​ (13) ​ — ​ (13) ​ Recoveries ​ — ​ — ​ — ​ 2 ​ — ​ 2 ​ Net charge-offs ​ — ​ — ​ — ​ (11) ​ — ​ (11) ​ Balance, end of period ​ $ 1,889 ​ $ 445 ​ $ 1 ​ $ 111 ​ $ 353 ​ $ 2,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Construction, Home Commercial Equity and Other Loans and Residential Mortgage Lines of Consumer (Dollars in thousands) Mortgage Loans Credit and Other Unallocated Totals Three months ended September 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 3,020 ​ $ 459 ​ $ 1 ​ $ 197 ​ $ 579 ​ $ 4,256 ​ Provision (reversal of provision) for loan losses ​ 988 ​ (2) ​ — ​ (21) ​ (273) ​ 692 ​ ​ ​ 4,008 ​ 457 ​ 1 ​ 176 ​ 306 ​ 4,948 ​ Charge-offs ​ — ​ — ​ — ​ (6) ​ — ​ (6) ​ Recoveries ​ — ​ — ​ — ​ — ​ — ​ — ​ Net charge-offs ​ — ​ — ​ — ​ (6) ​ — ​ (6) ​ Balance, end of period ​ $ 4,008 ​ $ 457 ​ $ 1 ​ $ 170 ​ $ 306 ​ $ 4,942 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance, beginning of period ​ $ 1,741 ​ $ 511 ​ $ 1 ​ $ 54 ​ $ 405 ​ $ 2,712 ​ Provision (reversal of provision) for loan losses ​ 2,267 ​ (54) ​ (10) ​ 200 ​ (99) ​ 2,304 ​ ​ ​ 4,008 ​ 457 ​ (9) ​ 254 ​ 306 ​ 5,016 ​ Charge-offs ​ — ​ — ​ — ​ (86) ​ — ​ (86) ​ Recoveries ​ — ​ — ​ 10 ​ 2 ​ — ​ 12 ​ Net recoveries (charge-offs) ​ — ​ — ​ 10 ​ (84) ​ — ​ (74) ​ Balance, end of period ​ $ 4,008 ​ $ 457 ​ $ 1 ​ $ 170 ​ $ 306 ​ $ 4,942 ​
Schedule of balance in allowance for loan losses and the recorded investment in loans by portfolio segment and based on impairment method	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Construction, Home Commercial Equity and Other Loans and Residential Mortgage Lines of Consumer (Dollars in thousands) Mortgage Loans Credit and Other Unallocated Totals September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for loan losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending allowance balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ Collectively evaluated for impairment ​ 1,889 ​ 445 ​ 1 ​ 111 ​ 353 ​ 2,799 ​ Total ending allowance balance ​ $ 1,889 ​ $ 445 ​ $ 1 ​ $ 111 ​ $ 353 ​ $ 2,799 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending loan balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ 4,785 ​ $ — ​ $ 19 ​ $ — ​ $ — ​ $ 4,804 ​ Collectively evaluated for impairment ​ 1,267,080 ​ 19,223 ​ 7,077 ​ 8,584 ​ — ​ 1,301,964 ​ Total ending loan balance ​ $ 1,271,865 ​ $ 19,223 ​ $ 7,096 ​ $ 8,584 ​ $ — ​ $ 1,306,768 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Allowance for loan losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending allowance balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ Collectively evaluated for impairment ​ 3,102 ​ 406 ​ 1 ​ 146 ​ 607 ​ 4,262 ​ Total ending allowance balance ​ $ 3,102 ​ $ 406 ​ $ 1 ​ $ 146 ​ $ 607 ​ $ 4,262 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ending loan balance: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Individually evaluated for impairment ​ $ 4,947 ​ $ — ​ $ 23 ​ $ — ​ $ — ​ $ 4,970 ​ Collectively evaluated for impairment ​ 1,367,576 ​ 19,024 ​ 9,353 ​ 10,334 ​ — ​ 1,406,287 ​ Total ending loan balance ​ $ 1,372,523 ​ $ 19,024 ​ $ 9,376 ​ $ 10,334 ​ $ — ​ $ 1,411,257 ​ ​
Schedule of balance of impaired loans individually evaluated for impairment by class of loans	​ ​ ​ ​ ​ ​ ​ ​ ​ Unpaid Recorded Principal (Dollars in thousands) Investment Balance September 30, 2021: ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 4,785 ​ $ 5,358 ​ Home equity loans and lines of credit ​ 19 ​ 31 ​ Total ​ $ 4,804 ​ $ 5,389 ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 4,947 ​ $ 5,425 ​ Home equity loans and lines of credit ​ ​ 23 ​ ​ 32 ​ Total ​ $ 4,970 ​ $ 5,457 ​
Schedule of average recorded investment and interest income recognized on impaired loans by class of loans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended For the Nine Months Ended September 30, September 30, Average Interest Average Interest Recorded Income Recorded Income (Dollars in thousands) Investment Recognized Investment Recognized 2021: ​ ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 4,816 ​ $ 8 ​ $ 4,866 ​ $ 28 ​ Home equity loans and lines of credit ​ 20 ​ — ​ 21 ​ — ​ Total ​ $ 4,836 ​ $ 8 ​ $ 4,887 ​ $ 28 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ With no related allowance recorded: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 2,745 ​ $ 8 ​ $ 2,770 ​ $ 25 ​ Home equity loans and lines of credit ​ ​ 24 ​ — ​ 25 ​ — ​ Total ​ $ 2,769 ​ $ 8 ​ $ 2,795 ​ $ 25 ​
Schedule of aging of loans and accrual status by class of loans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Loans 90 Days or More 30 - 59 60 - 89 90 Days or Past Due Days Past Days Past More Total Past Loans Not Total Nonaccrual and Still (Dollars in thousands) Due Due Past Due Due Past Due Loans Loans Accruing September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ — ​ $ — ​ $ 99 ​ $ 99 ​ $ 1,265,201 ​ $ 1,265,300 ​ $ 4,230 ​ $ — ​ Multi-family residential mortgages ​ — ​ — ​ — ​ — ​ 6,565 ​ 6,565 ​ — ​ — ​ Construction, commercial and other mortgages ​ — ​ — ​ — ​ — ​ 19,223 ​ 19,223 ​ — ​ — ​ Home equity loans and lines of credit ​ — ​ — ​ — ​ — ​ 7,096 ​ 7,096 ​ 19 ​ — ​ Loans on deposit accounts ​ — ​ — ​ — ​ — ​ 290 ​ 290 ​ — ​ — ​ Consumer and other ​ 5 ​ 23 ​ — ​ 28 ​ 8,266 ​ 8,294 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 5 ​ $ 23 ​ $ 99 ​ $ 127 ​ $ 1,306,641 ​ $ 1,306,768 ​ $ 4,249 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ $ 376 ​ $ 152 ​ $ 240 ​ $ 768 ​ $ 1,364,527 ​ $ 1,365,295 ​ $ 4,382 ​ $ — ​ Multi-family residential mortgages ​ — ​ — ​ — ​ — ​ 7,228 ​ 7,228 ​ — ​ — ​ Construction, commercial and other mortgages ​ — ​ — ​ — ​ — ​ 19,024 ​ 19,024 ​ — ​ — ​ Home equity loans and lines of credit ​ — ​ 23 ​ — ​ 23 ​ 9,353 ​ 9,376 ​ 23 ​ — ​ Loans on deposit accounts ​ — ​ — ​ — ​ — ​ 235 ​ 235 ​ — ​ — ​ Consumer and other ​ 1 ​ — ​ — ​ 1 ​ 10,098 ​ 10,099 ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 377 ​ $ 175 ​ $ 240 ​ $ 792 ​ $ 1,410,465 ​ $ 1,411,257 ​ $ 4,405 ​ $ — ​
Summary of troubled debt restructurings by class of loan	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of Accrual Number of Nonaccrual ​ (Dollars in thousands) Loans Status Loans Status Total September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ 3 ​ $ 554 ​ ​ 2 ​ $ 425 ​ $ 979 Total ​ 3 ​ $ 554 ​ ​ 2 ​ $ 425 ​ $ 979 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One- to four-family residential mortgages ​ 3 ​ $ 565 ​ ​ 2 ​ $ 467 ​ $ 1,032 Total ​ 3 ​ $ 565 ​ ​ 2 ​ $ 467 ​ $ 1,032

Securities Sold Under Agreeme_2

Securities Sold Under Agreements to Repurchase (Tables)	9 Months Ended
	Sep. 30, 2021
Securities Sold Under Agreements to Repurchase
Summary of securities sold under agreements to repurchase	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 December 31, 2020 Weighted Weighted Repurchase Average Repurchase Average (Dollars in thousands) Liability Rate Liability Rate Maturing: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Over 3 years to 4 years ​ $ 10,000 1.81 % $ 5,000 1.88 % Over 4 years to 5 years ​ — — ​ 5,000 1.73 % Total ​ $ 10,000 1.81 % $ 10,000 1.81 %
Summary comparing carrying value and fair value of securities pledged to secure repurchase agreements, repurchase liability, and amount at risk	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Carrying Fair Average Value of Value of Repurchase Amount Months to (Dollars in thousands) Securities Securities Liability at Risk Maturity Maturing: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Over 90 days ​ $ 11,990 ​ $ 12,402 ​ $ 10,000 ​ $ 2,402 39 ​

Offsetting of Financial Liabi_2

Offsetting of Financial Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Offsetting of Financial Liabilities
Schedule of securities sold under agreements to repurchase subject to conditional right of offset	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net Amount of Gross Amount Not Offset in the Gross Amount Gross Amount Liabilities Balance Sheet of Recognized Offset in the Presented in the Financial Cash Collateral (Dollars in thousands) Liabilities Balance Sheet Balance Sheet Instruments ​ Pledged Net Amount September 30, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities sold under agreements to repurchase ​ $ 10,000 ​ $ — ​ $ 10,000 ​ $ 10,000 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities sold under agreements to repurchase ​ $ 10,000 ​ $ — ​ $ 10,000 ​ $ 10,000 ​ $ — ​ $ —

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Employee Benefit Plans
Schedule of components of net periodic benefit cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SERP SERP Three Months Ended Nine Months Ended September 30, September 30, (Dollars in thousands) 2021 2020 2021 2020 Net periodic benefit cost for the period: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost ​ $ 2 ​ $ 22 ​ $ 7 ​ $ 66 ​ Interest cost ​ 45 ​ 43 ​ 135 ​ 130 ​ Expected return on plan assets ​ — ​ — ​ — ​ — ​ Amortization of prior service cost ​ — ​ — ​ — ​ — ​ Recognized actuarial loss ​ — ​ — ​ — ​ — ​ Recognized curtailment loss ​ — ​ — ​ — ​ — ​ Net periodic benefit cost ​ $ 47 ​ $ 65 ​ $ 142 ​ $ 196 ​

Employee Stock Ownership Plan (

Employee Stock Ownership Plan (Tables)	9 Months Ended
	Sep. 30, 2021
Employee Stock Ownership Plan
Schedule of shares held by the ESOP trust	​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, 2021 2020 Allocated shares ​ 528,636 ​ 507,304 ​ Unearned shares ​ 354,764 ​ 391,464 ​ Total ESOP shares ​ 883,400 ​ 898,768 ​ Fair value of unearned shares, in thousands ​ $ 9,004 ​ $ 9,407 ​

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Schedule of compensation expense and related tax benefit for all share-based awards	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended September 30, September 30, (In thousands) 2021 2020 2021 2020 Compensation expense ​ $ 36 ​ $ 157 ​ $ 241 ​ $ 523 ​ Income tax benefit ​ 10 ​ 43 ​ 66 ​ 143 ​
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Aggregate ​ ​ ​ ​ Average ​ Remaining ​ Intrinsic ​ ​ ​ ​ Exercise ​ Contractual ​ Value ​ ​ Options ​ Price ​ Life (years) ​ (in thousands) Options outstanding at December 31, 2020 3,085 ​ $ 23.62 1.67 ​ $ 1 ​ Granted — ​ — — ​ — ​ Exercised — ​ — — ​ — ​ Forfeited — ​ — — ​ — ​ Expired — ​ — — ​ — ​ Options outstanding at September 30, 2021 ​ 3,085 ​ $ 23.62 0.92 ​ $ 5 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options outstanding at December 31, 2019 116,409 ​ $ 17.53 0.72 ​ $ 1,562 ​ Granted — ​ — — ​ — ​ Exercised 81,827 ​ 17.36 — ​ 725 ​ Forfeited — ​ — — ​ — ​ Expired 31,497 ​ — — ​ — ​ Options outstanding at September 30, 2020 3,085 ​ $ 23.62 1.92 ​ $ (11) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options vested and exercisable at September 30, 2021 3,085 ​ $ 23.62 0.92 ​ $ 5 ​
Summary of certain stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended For the Nine Months Ended September 30, September 30, (In thousands) 2021 2020 2021 2020 Intrinsic value of stock options exercised ​ $ — ​ $ — ​ $ — ​ $ 725 ​ Proceeds received from stock options exercised ​ — ​ — ​ — ​ 1,421 ​ Tax benefits realized from stock options exercised ​ — ​ — ​ — ​ 158 ​ Total fair value of stock options that vested ​ — ​ — ​ — ​ — ​
Restricted Stock
Schedule of restricted stock award activity	​ ​ ​ ​ ​ ​ ​ Weighted Time-Based Average Grant Restricted Date Fair Stock Value Unvested at December 31, 2020 23,695 ​ $ 24.24 ​ Granted 10,849 ​ 26.67 ​ Vested 11,336 ​ 25.81 ​ Forfeited — ​ — ​ Unvested at September 30, 2021 23,208 ​ $ 24.61 ​ ​ ​ ​ ​ ​ ​ ​ Unvested at December 31, 2019 20,249 ​ $ 28.78 ​ Granted 13,444 ​ 21.05 ​ Vested 9,998 ​ 29.16 ​ Forfeited — ​ — ​ Unvested at September 30, 2020 23,695 ​ $ 24.24 ​
Restricted Stock Units Based on a Performance Condition
Schedule of restricted stock award activity	​ ​ ​ ​ ​ ​ Performance- ​ ​ ​ ​ Based Restricted ​ ​ ​ Stock Units Weighted ​ ​ Based on a ​ Average Grant ​ ​ Performance ​ Date Fair Condition Value Unvested at December 31, 2020 40,585 ​ $ 25.83 Granted 13,016 ​ 26.67 Vested 7,473 ​ 30.73 Forfeited 4,545 ​ 30.73 Unvested at September 30, 2021 41,583 ​ $ 24.68 ​ ​ ​ ​ ​ ​ Unvested at December 31, 2019 35,976 ​ $ 29.16 Granted 16,129 ​ 21.05 Vested 7,680 ​ 29.53 Forfeited 3,840 ​ 29.53 Unvested at September 30, 2020 40,585 ​ $ 25.83
Restricted Stock Units Based on a Market Condition
Schedule of restricted stock award activity	​ ​ ​ ​ ​ ​ ​ ​ Performance- ​ ​ ​ ​ ​ Based Restricted ​ Monte Carlo ​ ​ Stock Units ​ Valuation of ​ ​ Based on a ​ the Company's Market Condition Stock Unvested at December 31, 2020 10,147 ​ $ 24.69 Granted 3,254 ​ ​ 25.94 Vested 1,628 ​ 28.32 Forfeited 1,377 ​ 28.32 Unvested at September 30, 2021 10,396 ​ $ 24.03 ​ ​ ​ ​ ​ ​ Unvested at December 31, 2019 8,994 ​ $ 25.74 Granted 4,032 ​ 22.16 Vested 1,197 ​ 24.44 Forfeited 1,682 ​ 22.44 Unvested at September 30, 2020 10,147 ​ $ 24.69

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share
Schedule of information used to compute basic and diluted earnings per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended September 30, September 30, ​ (Dollars in thousands, except per share data) 2021 2020 2021 2020 Net income ​ $ 4,162 ​ $ 4,318 ​ $ 13,233 ​ $ 13,082 ​ ​ Income allocated to participating securities ​ ​ (23) ​ ​ (23) ​ ​ (47) ​ ​ (47) ​ ​ Net income available to common shareholders ​ $ 4,139 ​ $ 4,295 ​ $ 13,186 ​ $ 13,035 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average number of shares used in: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share ​ 9,012,398 ​ 9,104,079 ​ 9,086,447 ​ 9,144,463 ​ ​ Dilutive common stock equivalents: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options and restricted stock units ​ 44,171 ​ 30,010 ​ 44,622 ​ 57,419 ​ ​ Diluted earnings per share ​ 9,056,569 ​ 9,134,089 ​ 9,131,069 ​ 9,201,882 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income per common share, basic ​ $ 0.46 ​ $ 0.47 ​ $ 1.45 ​ $ 1.43 ​ ​ Net income per common share, diluted ​ $ 0.46 ​ $ 0.47 ​ $ 1.44 ​ $ 1.42 ​ ​

Other Comprehensive Income an_2

Other Comprehensive Income and Loss (Tables)	9 Months Ended
	Sep. 30, 2021
Other Comprehensive Income and Loss
Schedule of changes in components of accumulated other comprehensive income and loss, net of taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unfunded Unrealized Pension (Gain)/Loss on (Dollars in thousands) Liability Securities Total Three months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,967 ​ $ — ​ $ 8,967 ​ Net current period other comprehensive loss ​ — ​ — ​ — ​ Balances at end of period ​ $ 8,967 ​ $ — ​ $ 8,967 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,178 ​ $ (315) ​ $ 7,863 ​ Other comprehensive loss, net of taxes ​ — ​ 4 ​ 4 ​ Net current period other comprehensive loss ​ — ​ 4 ​ 4 ​ Balances at end of period ​ $ 8,178 ​ $ (311) ​ $ 7,867 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,967 ​ $ (276) ​ $ 8,691 ​ Other comprehensive loss, net of taxes ​ — ​ 3 ​ 3 ​ Amounts reclassified from other comprehensive income, net of taxes ​ — ​ 273 ​ 273 ​ Net current period other comprehensive loss ​ — ​ 276 ​ 276 ​ Balances at end of period ​ $ 8,967 ​ $ — ​ $ 8,967 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at beginning of period ​ $ 8,178 ​ $ (510) ​ $ 7,668 ​ Other comprehensive income, net of taxes ​ ​ — ​ ​ (22) ​ ​ (22) ​ Amounts reclassified from other comprehensive income, net of taxes ​ — ​ 221 ​ 221 ​ Net current period other comprehensive loss ​ — ​ 199 ​ 199 ​ Balances at end of period ​ $ 8,178 ​ $ (311) ​ $ 7,867 ​
Schedule of tax effect on each component of accumulated other comprehensive loss	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, 2021 2020 Pretax After Tax Pretax After Tax (Dollars in thousands) Amount Tax Amount Amount Tax Amount Unrealized loss on securities ​ $ — ​ $ — ​ $ — ​ $ 5 ​ $ (1) ​ $ 4 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ 2021 2020 ​ Pretax After Tax Pretax After Tax (Dollars in thousands) Amount Tax Amount Amount Tax Amount Unrealized loss (gain) on securities ​ $ 4 ​ $ (1) ​ $ 3 ​ $ (30) ​ $ 8 ​ $ (22) ​ Amount reclassified from other comprehensive income ​ ​ 373 ​ ​ (100) ​ ​ 273 ​ ​ 301 ​ ​ (80) ​ ​ 221 ​ Total ​ $ 377 ​ $ (101) ​ $ 276 ​ $ 271 ​ $ (72) ​ $ 199 ​

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue Recognition
Reconciliation of revenue from contracts with customers and other revenue reported in line items	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service and ​ ​ ​ ​ (Dollars in thousands) Other Fees Other Total Three months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 399 ​ $ 30 ​ $ 429 Other revenue ​ ​ 34 ​ ​ 27 ​ ​ 61 Total ​ $ 433 ​ $ 57 ​ $ 490 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 715 ​ $ 35 ​ $ 750 Other revenue ​ ​ 13 ​ ​ 28 ​ ​ 41 Total ​ $ 728 ​ $ 63 ​ $ 791 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 1,855 ​ $ 154 ​ $ 2,009 Other revenue ​ ​ 103 ​ ​ 83 ​ ​ 186 Total ​ $ 1,958 ​ $ 237 ​ $ 2,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue from contracts with customers ​ $ 1,639 ​ $ 88 ​ $ 1,727 Other revenue ​ ​ 77 ​ ​ 83 ​ ​ 160 Total ​ $ 1,716 ​ $ 171 ​ $ 1,887

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases
Schedule of lease costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended Nine Months Ended ​ September 30, September 30, (Dollars in thousands) 2021 2020 2021 2020 Lease costs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating lease costs ​ $ 843 ​ $ 878 ​ $ 2,552 ​ $ 2,509 ​ Short-term lease costs ​ 15 ​ 5 ​ 32 ​ 17 ​ Variable lease costs ​ 31 ​ 38 ​ 113 ​ 115 ​ Total lease costs ​ $ 889 ​ $ 921 ​ $ 2,697 ​ $ 2,641 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in measurement of lease liabilities ​ $ 836 ​ $ 808 ​ $ 2,520 ​ $ 2,414 ​ ROU assets obtained in exchange for new operating lease liabilities ​ $ 444 ​ $ 2,247 ​ $ 3,285 ​ $ 4,033 ​ ​
Schedule of future minimum rental commitments under noncancellable operating leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ $ 801 ​ ​ ​ ​ ​ ​ 2022 ​ 3,048 ​ ​ ​ ​ ​ ​ 2023 ​ 2,697 ​ ​ ​ ​ ​ ​ 2024 ​ 2,441 ​ ​ ​ ​ ​ ​ 2025 ​ 1,740 ​ ​ ​ ​ ​ ​ Thereafter ​ 4,264 ​ ​ ​ ​ ​ ​ Total ​ ​ 14,991 ​ ​ ​ ​ ​ ​ Less present value discount ​ ​ (872) ​ ​ ​ ​ ​ ​ Present value of leases ​ $ 14,119 ​ ​ ​ ​ ​ ​ ​
Schedule of other lease related information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ ​ September 30, ​ ​ ​ 2021 ​ 2020 ​ Weighted-average remaining lease term (years) ​ 5.95 ​ ​ 6.00 ​ ​ Weighted-average discount rate ​ ​ 2.18 % ​ ​ 2.45 % ​

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2021
Schedule of estimated fair values of financial instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying ​ ​ ​ ​ Fair Value Measurements Using (Dollars in thousands) Amount Fair Value Level 1 Level 2 Level 3 September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 101,386 ​ $ 101,386 ​ $ 101,386 ​ $ — ​ $ — ​ Investment securities held to maturity ​ 621,417 ​ ​ 623,406 ​ ​ — ​ ​ 623,406 ​ ​ — ​ Loans held for sale ​ 488 ​ ​ 489 ​ ​ — ​ ​ 489 ​ ​ — ​ Loans receivable, net ​ 1,303,969 ​ ​ 1,362,554 ​ ​ — ​ ​ — ​ ​ 1,362,554 ​ FHLB stock ​ 8,173 ​ ​ 8,173 ​ ​ — ​ ​ 8,173 ​ ​ — ​ FRB stock ​ ​ 3,158 ​ ​ 3,158 ​ ​ — ​ ​ 3,158 ​ ​ — ​ Accrued interest receivable ​ 6,070 ​ ​ 6,070 ​ ​ 18 ​ ​ 1,159 ​ ​ 4,893 ​ Interest rate contracts ​ 209 ​ ​ 209 ​ ​ — ​ ​ 209 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deposits ​ 1,664,963 ​ ​ 1,666,163 ​ ​ — ​ ​ 1,429,153 ​ ​ 237,010 ​ Advances from the Federal Home Loan Bank ​ 141,000 ​ ​ 143,498 ​ ​ — ​ ​ 143,498 ​ ​ — ​ Securities sold under agreements to repurchase ​ 10,000 ​ ​ 10,279 ​ ​ — ​ ​ 10,279 ​ ​ — ​ Accrued interest payable ​ 52 ​ ​ 52 ​ ​ — ​ ​ 50 ​ ​ 2 ​ Interest rate contracts ​ 209 ​ ​ 209 ​ ​ — ​ ​ 209 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 363,543 ​ $ 363,543 ​ $ 363,543 ​ $ — ​ $ — ​ Investment securities available for sale ​ ​ 3,562 ​ ​ 3,562 ​ ​ — ​ ​ 3,562 ​ ​ — ​ Investment securities held to maturity ​ 247,642 ​ ​ 262,841 ​ ​ — ​ ​ 262,841 ​ ​ — ​ Loans held for sale ​ 2,195 ​ ​ 2,274 ​ ​ — ​ ​ 2,274 ​ ​ — ​ Loans receivable, net ​ 1,406,995 ​ ​ 1,433,489 ​ ​ — ​ ​ — ​ ​ 1,433,489 ​ FHLB stock ​ 8,144 ​ ​ 8,144 ​ ​ — ​ ​ 8,144 ​ ​ — ​ FRB stock ​ ​ 3,145 ​ ​ 3,145 ​ ​ — ​ ​ 3,145 ​ ​ — ​ Accrued interest receivable ​ 6,515 ​ ​ 6,515 ​ ​ 16 ​ ​ 627 ​ ​ 5,872 ​ Interest rate contracts ​ 38 ​ ​ 38 ​ ​ — ​ ​ 38 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deposits ​ 1,659,800 ​ ​ 1,663,226 ​ ​ — ​ ​ 1,338,022 ​ ​ 325,204 ​ Advances from the Federal Home Loan Bank ​ 141,000 ​ ​ 145,441 ​ ​ — ​ ​ 145,441 ​ ​ — ​ Securities sold under agreements to repurchase ​ 10,000 ​ ​ 10,466 ​ ​ — ​ ​ 10,466 ​ ​ — ​ Accrued interest payable ​ 35 ​ ​ 35 ​ ​ — ​ ​ 33 ​ ​ 2 ​ Interest rate contracts ​ 38 ​ ​ 38 ​ ​ — ​ ​ 38 ​ ​ — ​
Schedule of assets and liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands) Level 1 Level 2 Level 3 Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate contracts — assets ​ $ — ​ $ 209 ​ $ — ​ $ 209 ​ Interest rate contracts — liabilities ​ — ​ (209) ​ — ​ (209) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate contracts — assets ​ $ — ​ $ 38 ​ $ — ​ $ 38 ​ Interest rate contracts — liabilities ​ — ​ (38) ​ — ​ (38) ​ Investment securities available for sale ​ — ​ 3,562 ​ — ​ 3,562 ​
Schedule of Significant unobservable inputs for Level 3 nonrecurring fair value measurements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unobservable Range (Dollars in thousands) Fair Value Valuation Technique Input (Weighted Average) December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mortgage servicing assets ​ $ 407 Discounted cash flow Discount rate ​ ​ 9.25% - 11.25% (10.25%) ​ ​ ​ ​ ​ ​ ​ Prepayment speed (CPR) ​ 10.42 - 19.61 (13.57) ​ ​ ​ ​ ​ ​ ​ Annual cost to service (per loan, in dollars) ​ $ 75 ​
Fair Value, Measurements, Nonrecurring
Schedule of balance of assets measured at fair value on a nonrecurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value ​ ​ (Dollars in thousands) Adjustment Date ​ Level 1 Level 2 Level 3 Total ​ Total Losses ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mortgage servicing assets ​ 12/31/2020 ​ $ — ​ $ — ​ $ 407 ​ $ 407 ​ $ (73) ​

Organization - Narrative (Detai

Organization - Narrative (Details)	9 Months Ended
	Sep. 30, 2021subsidiary
Organization
Number of inactive subsidiaries	1

Cash and Cash Equivalents (Deta

Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Cash and Cash Equivalents
Cash and due from banks	$ 11,361	$ 14,355
Interest-earning deposits in other banks	90,025	349,188
Cash and cash equivalents	$ 101,386	$ 363,543

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Fair Values of Available-for-Sale Securities (Details) $ in Thousands	Dec. 31, 2020USD ($)
Available-for-sale:
Amortized Cost	$ 3,185
Gross Unrealized Gains	377
Estimated Fair Value	3,562
U.S. government-sponsored mortgage-backed securities
Available-for-sale:
Amortized Cost	3,185
Gross Unrealized Gains	377
Estimated Fair Value	$ 3,562

Investment Securities - Amort_2

Investment Securities - Amortized Cost and Fair Values of Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Held-to-maturity:
Amortized Cost	$ 621,417	$ 247,642
Gross Unrealized Gains	7,682	15,200
Gross Unrealized Losses	(5,693)	(1)
Estimated Fair Value	623,406	262,841
U.S. government-sponsored mortgage-backed securities
Held-to-maturity:
Amortized Cost	621,417	247,642
Gross Unrealized Gains	7,682	15,200
Gross Unrealized Losses	(5,693)	(1)
Estimated Fair Value	$ 623,406	$ 262,841

Investment Securities - Maturit

Investment Securities - Maturity Schedule of Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Held-to-maturity, Amortized Cost
Due within 5 years	$ 17
Due after 5 years through 10 years	30
Due after 10 years	621,370
Amortized Cost	621,417	$ 247,642
Held-to-maturity, Estimated Fair Value
Due within 5 years	17
Due after 5 years through 10 years	30
Due after 10 years	623,359
Estimated Fair Value	$ 623,406	$ 262,841

Investment Securities - Realize

Investment Securities - Realized Gains and Losses and Proceeds from Sales (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Realized gains and losses and the proceeds from sales of securities
Proceeds from sales			$ 23,570,000	$ 10,429,000
U.S. government-sponsored mortgage-backed securities
Realized gains and losses and the proceeds from sales of securities
Gross gains			1,500,000	568,000
Available-for-sale mortgage-backed securities sold			3,000,000	3,400,000
Debt Securities, Available-for-sale, Realized Gain			339,000	290,000
U.S. government-sponsored mortgage-backed securities
Realized gains and losses and the proceeds from sales of securities
Proceeds from sales			$ 22,100,000	9,900,000
Minimum | U.S. government-sponsored mortgage-backed securities
Realized gains and losses and the proceeds from sales of securities
Portion of outstanding purchased principal already collected			85.00%
Held-to-maturity debt securities
Realized gains and losses and the proceeds from sales of securities
Proceeds from sales	$ 7,539,000	$ 5,737,000	$ 26,900,000	14,097,000
Gross gains	$ 403,000	$ 261,000	$ 1,840,000	$ 858,000

Investment Securities - Securit

Investment Securities - Securities Pledged (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Pledged investment securities
Investment securities pledged to secure deposits made by state and local governments, securities sold under agreements to repurchase and transaction clearing accounts	$ 148.4	$ 192.7

Investment Securities - Held-to

Investment Securities - Held-to-Maturity Unrealized Loss Position Summary (Details) - U.S. government-sponsored mortgage-backed securities $ in Thousands	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Investment Securities
Less Than 12 Months Fair Value	$ 439,788	$ 678
Less Than 12 Months Unrealized Losses	(5,692)	(1)
12 Months or Longer Fair Value	42	$ 4
12 Months or Longer Unrealized Losses	$ (1)
Total Number of Securities	32	6
Total Fair Value	$ 439,830	$ 682
Total Unrealized Losses	$ (5,693)	$ (1)

Investment Securities - Mortgag

Investment Securities - Mortgage-Backed Securities (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Schedule of Investments [Line Items]
Fair market value of received mortgage-backed securities		$ 9,800,000
Net gain recognized on the securitization transaction		377,000
Fixed-rate mortgage loans
Schedule of Investments [Line Items]
Book value		9,400,000
Securitized fixed-rate first mortgage loans		9,400,000
Net gain recognized on the securitization transaction	$ 0	$ 377,000

Loans Receivable and Allowanc_3

Loans Receivable and Allowance for Loan Losses - Components (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Loans receivable
Less: Net unearned fees and discounts	$ (1,503)		$ (1,266)
Less: Allowance for loan losses	(2,799)	$ (2,969)	(4,262)	$ (4,942)	$ (4,256)	$ (2,712)
Total unearned fees, discounts and allowance for loan losses	(4,302)		(5,528)
Loans receivable, net	1,303,969		1,406,995
Construction, commercial and other
Loans receivable
Less: Allowance for loan losses	(445)	(434)	(406)	(457)	(459)	(511)
Home Equity Loans and Lines of Credit
Loans receivable
Less: Allowance for loan losses	(1)	(1)	(1)	(1)	(1)	(1)
Consumer and other loans
Loans receivable
Less: Allowance for loan losses	(111)	(133)	(146)	(170)	(197)	(54)
Unallocated
Loans receivable
Less: Allowance for loan losses	(353)	$ (380)	(607)	$ (306)	$ (579)	$ (405)
Real estate loans
Loans receivable
Loans receivable, net	1,299,688		1,402,202
Real estate loans | One- to four-family residential
Loans receivable
Loans receivable, net	1,266,739		1,366,507
Real estate loans | Multi-family residential mortgages
Loans receivable
Loans receivable, net	6,577		7,245
Real estate loans | Construction, commercial and other
Loans receivable
Loans receivable, net	19,281		19,074
Real estate loans | Home Equity Loans and Lines of Credit
Loans receivable
Loans receivable, net	7,091		9,376
Other loans
Loans receivable
Loans receivable, net	8,583		10,321
Other loans | Loans on deposit accounts
Loans receivable
Loans receivable, net	290		235
Other loans | Consumer and other loans
Loans receivable
Loans receivable, net	$ 8,293		$ 10,086

Loans Receivable and Allowanc_4

Loans Receivable and Allowance for Loan Losses - Activity in Allowance for Loan Losses by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Activity in allowance for loan losses
Balance, beginning of period	$ 2,969	$ 4,256	$ 4,262	$ 2,712
(Reversal of provision) provision for loan losses	(167)	692	(1,452)	2,304
Allowance for loan losses on loans receivable after provision (reversal of allowance)	2,802	4,948	2,810	5,016
Charge-offs	(3)	(6)	(13)	(86)
Recoveries			2	12
Net recoveries (charge-offs)	(3)	(6)	(11)	(74)
Balance, end of period	2,799	4,942	2,799	4,942
Residential Mortgage
Activity in allowance for loan losses
Balance, beginning of period	2,021	3,020	3,102	1,741
(Reversal of provision) provision for loan losses	(132)	988	(1,213)	2,267
Allowance for loan losses on loans receivable after provision (reversal of allowance)	1,889	4,008	1,889	4,008
Balance, end of period	1,889	4,008	1,889	4,008
Construction, commercial and other
Activity in allowance for loan losses
Balance, beginning of period	434	459	406	511
(Reversal of provision) provision for loan losses	11	(2)	39	(54)
Allowance for loan losses on loans receivable after provision (reversal of allowance)	445	457	445	457
Balance, end of period	445	457	445	457
Home Equity Loans and Lines of Credit
Activity in allowance for loan losses
Balance, beginning of period	1	1	1	1
(Reversal of provision) provision for loan losses				(10)
Allowance for loan losses on loans receivable after provision (reversal of allowance)	1	1	1	(9)
Recoveries				10
Net recoveries (charge-offs)				10
Balance, end of period	1	1	1	1
Consumer and other loans
Activity in allowance for loan losses
Balance, beginning of period	133	197	146	54
(Reversal of provision) provision for loan losses	(19)	(21)	(24)	200
Allowance for loan losses on loans receivable after provision (reversal of allowance)	114	176	122	254
Charge-offs	(3)	(6)	(13)	(86)
Recoveries			2	2
Net recoveries (charge-offs)	(3)	(6)	(11)	(84)
Balance, end of period	111	170	111	170
Unallocated
Activity in allowance for loan losses
Balance, beginning of period	380	579	607	405
(Reversal of provision) provision for loan losses	(27)	(273)	(254)	(99)
Allowance for loan losses on loans receivable after provision (reversal of allowance)	353	306	353	306
Balance, end of period	$ 353	$ 306	$ 353	$ 306

Loans Receivable and Allowanc_5

Loans Receivable and Allowance for Loan Losses - Allowance for Loan Losses and Loans, Net of Unearned Fees and Discounts, by Segment (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Allowance for loan losses:
Collectively evaluated for impairment	$ 2,799		$ 4,262
Total ending allowance balance	2,799	$ 2,969	4,262	$ 4,942	$ 4,256	$ 2,712
Loans:
Individually evaluated for impairment	4,804		4,970
Collectively evaluated for impairment	1,301,964		1,406,287
Total ending loan balance	1,306,768		1,411,257
Residential Mortgage
Allowance for loan losses:
Collectively evaluated for impairment	1,889		3,102
Total ending allowance balance	1,889	2,021	3,102	4,008	3,020	1,741
Loans:
Individually evaluated for impairment	4,785		4,947
Collectively evaluated for impairment	1,267,080		1,367,576
Total ending loan balance	1,271,865		1,372,523
Construction, commercial and other
Allowance for loan losses:
Collectively evaluated for impairment	445		406
Total ending allowance balance	445	434	406	457	459	511
Loans:
Collectively evaluated for impairment	19,223		19,024
Total ending loan balance	19,223		19,024
Home Equity Loans and Lines of Credit
Allowance for loan losses:
Collectively evaluated for impairment	1		1
Total ending allowance balance	1	1	1	1	1	1
Loans:
Individually evaluated for impairment	19		23
Collectively evaluated for impairment	7,077		9,353
Total ending loan balance	7,096		9,376
Consumer and other loans
Allowance for loan losses:
Collectively evaluated for impairment	111		146
Total ending allowance balance	111	133	146	170	197	54
Loans:
Collectively evaluated for impairment	8,584		10,334
Total ending loan balance	8,584		10,334
Unallocated
Allowance for loan losses:
Collectively evaluated for impairment	353		607
Total ending allowance balance	$ 353	$ 380	$ 607	$ 306	$ 579	$ 405

Loans Receivable and Allowanc_6

Loans Receivable and Allowance for Loan Losses - Impaired Loans by Class (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Impaired loans
Recorded Investment	$ 4,804		$ 4,804		$ 4,970
Unpaid Principal Balance	5,389		5,389		5,457
Average Recorded Investment	4,836	$ 2,769	4,887	$ 2,795
Interest Income Recognized	8	8	28	25
One- to four-family residential
Impaired loans
Recorded Investment	4,785		4,785		4,947
Unpaid Principal Balance	5,358		5,358		5,425
Average Recorded Investment	4,816	2,745	4,866	2,770
Interest Income Recognized	8	8	28	25
Home equity loans and lines of credit
Impaired loans
Recorded Investment	19		19		23
Unpaid Principal Balance	31		31		$ 32
Average Recorded Investment	$ 20	$ 24	$ 21	$ 25

Loans Receivable and Allowanc_7

Loans Receivable and Allowance for Loan Losses - Delinquent and Nonaccrual Loans (Details)	9 Months Ended
	Sep. 30, 2021USD ($)loan	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)loan
Loans Receivable and Allowance for Loan Losses
Loans individually evaluated for impairment with a related allowance for loan loss	$ 0		$ 0
Number of nonaccrual loans | loan	12		12
Nonaccrual Loans	$ 4,249,000		$ 4,405,000
Interest collected on nonaccrual loans recorded as a reduction of principal	102,000	$ 40,000
Non accrual loans, additional interest income that would have been recognized had the loans been accruing interest	$ 194,000	$ 68,000
Loan delinquency period that may result in loss	90 days
Loan delinquency period after which an appraisal is obtained of the underlying collateral	4 months
Loans 90 Days or More Past Due and Still Accruing	$ 0		$ 0

Loans Receivable and Allowanc_8

Loans Receivable and Allowance for Loan Losses - Aging of Loans and Accrual Status by Class (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment, Past Due
Total Loans	$ 1,306,768,000	$ 1,411,257,000
Nonaccrual Loans	4,249,000	4,405,000
Loans 90 Days or More Past Due and Still Accruing	0	0
One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,265,300,000	1,365,295,000
Nonaccrual Loans	4,230,000	4,382,000
Loans 90 Days or More Past Due and Still Accruing	0	0
Multi-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	6,565,000	7,228,000
Loans 90 Days or More Past Due and Still Accruing	0	0
Construction, commercial and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	19,223,000	19,024,000
Loans 90 Days or More Past Due and Still Accruing	0	0
Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans	7,096,000	9,376,000
Nonaccrual Loans	19,000	23,000
Loans 90 Days or More Past Due and Still Accruing	0	0
Loans on deposit accounts
Financing Receivable, Recorded Investment, Past Due
Total Loans	290,000	235,000
Loans 90 Days or More Past Due and Still Accruing	0	0
Consumer and other loans
Financing Receivable, Recorded Investment, Past Due
Total Loans	8,294,000	10,099,000
Loans 90 Days or More Past Due and Still Accruing	0	0
Not Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,306,641,000	1,410,465,000
Not Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,265,201,000	1,364,527,000
Not Past Due | Multi-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	6,565,000	7,228,000
Not Past Due | Construction, commercial and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	19,223,000	19,024,000
Not Past Due | Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans	7,096,000	9,353,000
Not Past Due | Loans on deposit accounts
Financing Receivable, Recorded Investment, Past Due
Total Loans	290,000	235,000
Not Past Due | Consumer and other loans
Financing Receivable, Recorded Investment, Past Due
Total Loans	8,266,000	10,098,000
Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	127,000	792,000
Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	99,000	768,000
Past Due | Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans		23,000
Past Due | Consumer and other loans
Financing Receivable, Recorded Investment, Past Due
Total Loans	28,000	1,000
30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	5,000	377,000
30 - 59 Days Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans		376,000
30 - 59 Days Past Due | Consumer and other loans
Financing Receivable, Recorded Investment, Past Due
Total Loans	5,000	1,000
60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	23,000	175,000
60 - 89 Days Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans		152,000
60 - 89 Days Past Due | Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans		23,000
60 - 89 Days Past Due | Consumer and other loans
Financing Receivable, Recorded Investment, Past Due
Total Loans	23,000
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	99,000	240,000
90 Days or More Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	$ 99,000	$ 240,000

Loans Receivable and Allowanc_9

Loans Receivable and Allowance for Loan Losses - Troubled Debt Restructurings (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2021USD ($)loan	Sep. 30, 2020loan	Dec. 31, 2020USD ($)loan
Troubled debt restructurings
Troubled debt restructurings	$ 979,000		$ 1,032,000
Number of loans subsequently defaulted | loan	0	0
Additional disclosures
Loan deferrals granted, COVID-19	$ 90,400,000
Percentage of forbearance loans representing total loans receivable, COVID-19	6.90%
Real estate owned	$ 0		0
Percentage of current loan balance to the current tax-assessed value of the property securing mortgage loans COVID-19	55.90%
Delinquent
Troubled debt restructurings
Troubled debt restructurings	$ 0		$ 0
Accrual Status
Troubled debt restructurings
Number of Loans | loan	3		3
Troubled debt restructurings	$ 554,000		$ 565,000
Nonaccrual Status
Troubled debt restructurings
Number of Loans | loan	2		2
Troubled debt restructurings	$ 425,000		$ 467,000
Loans modified in troubled debt restructuring
Troubled debt restructurings
Number of Loans | loan	0	0
Additional disclosures
Commitments to lend additional funds to borrowers	$ 0
One- to four-family residential
Troubled debt restructurings
Troubled debt restructurings	979,000		$ 1,032,000
Additional disclosures
Loan deferrals granted, COVID-19	$ 86,500,000
Mortgage loans in process of foreclosure, number of contracts | loan	1		2
Mortgage loans in process of foreclosure, total value	$ 99,000		$ 251,000
Percentage of mortgage loans representing total loan portfolio balance	97.10%
Percentage of current loan balance to current tax	45.20%
Amount of loan deferred resumed payment of principal and interest, COVID-19	$ 66,500,000
Percentage of loan deferred which resumed payment of principal and interest, COVID-19	76.90%
Percentage of loan deferred making payment of interest, COVID-19	23.10%
Loans in the Loan Payment Deferral Program	$ 0
One- to four-family residential | Accrual Status
Troubled debt restructurings
Number of Loans | loan	3		3
Troubled debt restructurings	$ 554,000		$ 565,000
One- to four-family residential | Nonaccrual Status
Troubled debt restructurings
Number of Loans | loan	2		2
Troubled debt restructurings	$ 425,000		$ 467,000
Commercial mortgage, commercial and industrial and home equity lines of credit
Additional disclosures
Loan deferrals granted, COVID-19	3,900,000
Amount of loan deferred resumed payment of principal and interest, COVID-19	3,400,000
Residential Mortgage | One- to four-family residential
Additional disclosures
Amount of loan deferred making payment of interest, COVID-19	20,000,000
Home Equity Loans and Lines of Credit
Additional disclosures
Amount of loan deferred resumed payment of principal and interest, COVID-19	$ 478,000

Loans Receivable and Allowan_10

Loans Receivable and Allowance for Loan Losses - Loan Payment Deferral Program by Class (Details) $ in Thousands	Sep. 30, 2021USD ($)
COVID-19
Additional disclosures
Loans in the Loan Payment Deferral Program	$ 90,395
Percent of Total Loans	6.90%
One- to four-family residential
Additional disclosures
Loans in the Loan Payment Deferral Program	$ 0
One- to four-family residential | COVID-19
Additional disclosures
Loans in the Loan Payment Deferral Program	$ 86,538
Percent of Total Loans	6.60%
Non-residential Mortgage | COVID-19
Additional disclosures
Loans in the Loan Payment Deferral Program	$ 3,857
Percent of Total Loans	0.30%

Loans Receivable and Allowan_11

Loans Receivable and Allowance for Loan Losses - Collateral, Sales, Serviced for Others, Directors and Executive Officers (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)loan	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)loan	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)loan
Accounts, Notes, Loans and Financing Receivable
Loans serviced for others	$ 44,700,000		$ 44,700,000		$ 56,700,000
Fair market value of received mortgage-backed securities		$ 9,800,000		$ 9,800,000
Mortgage servicing assets		78,000		78,000
Net gain recognized on the securitization transaction				377,000
Loans serviced for others, securitization for which the company continues to hold the related mortgage-backed securities	26,600,000		26,600,000		$ 35,500,000
Loans serviced for others, amount of contractually specified servicing fees earned	$ 31,000	43,000	$ 99,000	134,000
Maximum
Accounts, Notes, Loans and Financing Receivable
Loan to value ratio (as a percent)	80.00%		80.00%
Residential Mortgage Loans Held For Sale
Accounts, Notes, Loans and Financing Receivable
Residential mortgage loans sold, loan amount			$ 26,200,000	22,300,000
Residential mortgage loans sold, recognized gains			$ 584,000	610,000
Number of nonaccrual loans | loan	1		1		5
Residential mortgage loans held for sale	$ 488,000		$ 488,000		$ 2,200,000
Fixed-rate mortgage loans
Accounts, Notes, Loans and Financing Receivable
Book value		$ 9,400,000		9,400,000
Net gain recognized on the securitization transaction			$ 0	$ 377,000

Securities Sold Under Agreeme_3

Securities Sold Under Agreements to Repurchase - Summary of Repurchase Liability by Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Securities sold under agreements to repurchase
Repurchase Liability	$ 10,000	$ 10,000
Weighted Average
Securities sold under agreements to repurchase
Rate (as a percent)	1.81%	1.81%
Over 3 years to 4 years
Securities sold under agreements to repurchase
Repurchase Liability	$ 10,000	$ 5,000
Over 3 years to 4 years | Weighted Average
Securities sold under agreements to repurchase
Rate (as a percent)	1.81%	1.88%
Over 4 years to 5 years
Securities sold under agreements to repurchase
Repurchase Liability		$ 5,000
Over 4 years to 5 years | Weighted Average
Securities sold under agreements to repurchase
Rate (as a percent)		1.73%

Securities Sold Under Agreeme_4

Securities Sold Under Agreements to Repurchase - Summary of Securities Pledged (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Securities sold under agreements to repurchase
Repurchase liability maximum	90.00%
Maturing Over 90 days
Securities sold under agreements to repurchase
Carrying Value of Securities	$ 11,990
Fair Value of Securities	12,402
Repurchase Liability	10,000
Amount at Risk	$ 2,402
Weighted Average Months to Maturity	39 months

Offsetting of Financial Liabi_3

Offsetting of Financial Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Securities sold under agreements to repurchase
Gross Amount of Recognized Liabilities	$ 10,000	$ 10,000
Net Amount of Liabilities Presented in the Balance Sheet	10,000	10,000
Gross amount not offset in the balance sheet
Financial Instruments	$ 10,000	$ 10,000

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Pension Plan | Minimum
Pension and Other Postretirement Benefit Contributions
Requisite service period for receiving benefits under the plan			1 year
Supplemental Employee Retirement Plan (SERP)
Net periodic benefit cost (income) for the year:
Service cost	$ 2	$ 22	$ 7	$ 66
Interest cost	45	43	135	130
Net periodic benefit cost	$ 47	$ 65	$ 142	$ 196

Employee Stock Ownership Plan -

Employee Stock Ownership Plan - Loan, Expense and Shares (Details) - USD ($)	Jan. 01, 2009	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Employee Stock Ownership Plan
Allocated shares		528,636		528,636		507,304
Unearned shares		354,764		354,764		391,464
Total ESOP shares		883,400		883,400		898,768
Fair value of unearned shares, in thousands		$ 9,004,000		$ 9,004,000		$ 9,407,000
ESOP
Employee Stock Ownership Plan
Amount borrowed from employer	$ 9,800,000
Shares purchased	978,650
Percentage of shares issued in initial public offering	8.00%
Employee stock ownership plan, price per share of shares acquired in initial public offering (in dollars per share)	$ 10
Term of loan				20 years
ESOP expense		$ 310,000	$ 264,000	$ 942,000	$ 905,000
ESOP | Prime rate
Employee Stock Ownership Plan
Variable interest rate				prime rate, as published in The Wall Street Journal

Employee Stock Ownership Plan_2

Employee Stock Ownership Plan - Nonqualified ESOP Restoration Plan (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
ESOP restoration | Certain executives
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits
Accrued (reversed) benefits	$ 41,000	$ 5,000	$ 94,000	$ 79,000

Share-Based Compensation - Plan

Share-Based Compensation - Plan Provisions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-Based Compensation
Shares remaining available for new awards under the 2019 Equity Plan	146,347		146,347
Compensation expense	$ 36	$ 157	$ 241	$ 523
Income tax benefit	$ 10	$ 43	$ 66	$ 143
2010 Equity Incentive Plan | Vesting period one
Share-Based Compensation
Vesting period			3 years
2010 Equity Incentive Plan | Vesting period two
Share-Based Compensation
Vesting period			5 years
2010 Equity Incentive Plan | Vesting period three
Share-Based Compensation
Vesting period			6 years

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Common Stock
Stock option activity
Exercised (in shares)		81,827
Stock Options
Stock option activity
Balance at beginning of period (in shares)	3,085	116,409	116,409
Exercised (in shares)		81,827
Expired (in shares)		31,497
Balance at end of period (in shares)	3,085	3,085	3,085	116,409
Options vested and exercisable (in shares)	3,085
Weighted Average Exercise Price
Balance at beginning of period (in dollars per share)	$ 23.62	$ 17.53	$ 17.53
Exercised (in dollars per share)		17.36
Balance at end of period (in dollars per share)	23.62	$ 23.62	$ 23.62	$ 17.53
Options vested and exercisable (in dollars per share)	$ 23.62
Remaining Contractual Life
Options outstanding	11 months 1 day	1 year 11 months 1 day	1 year 8 months 1 day	8 months 19 days
Options vested and exercisable	11 months 1 day
Aggregate Intrinsic Value
Beginning of period	$ 1	$ 1,562	$ 1,562
Exercised		725
End of period	5	(11)	$ 1	$ 1,562
Options vested and exercisable	5
Stock option activity
Intrinsic value of stock options exercised		725
Proceeds received from stock options exercised		1,421
Tax benefits realized from stock options exercised		$ 158
Unrecognized compensation costs	$ 0

Share-Based Compensation - Rest

Share-Based Compensation - Restricted Stock Awards (Details) - USD ($)	Apr. 05, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Unrecognized compensation
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		146,347
Restricted Stock
Restricted Stock Awards
Unvested at beginning of period (in shares)		23,695	20,249
Granted (in shares)		10,849	13,444
Vested (in shares)		11,336	9,998
Unvested at end of period (in shares)		23,208	23,695
Weighted Average Grant Date Fair Value
Unvested at beginning of period (in dollars per share)		$ 24.24	$ 28.78
Granted (in dollars per share)		26.67	21.05
Vested (in dollars per share)		25.81	29.16
Unvested at end of period (in dollars per share)		$ 24.61	$ 24.24
Unrecognized compensation
Unrecognized compensation costs		$ 418,000
Restricted Stock | 2019 Equity Incentive Plan
Restricted Stock Awards
Granted (in shares)		10,849
Unrecognized compensation
Vesting period		3 years
Restricted Stock Units Based on a Performance Condition
Restricted Stock Awards
Unvested at beginning of period (in shares)		40,585	35,976
Granted (in shares)		13,016	16,129
Vested (in shares)		7,473	7,680
Forfeited (in shares)		4,545	3,840
Unvested at end of period (in shares)		41,583	40,585
Weighted Average Grant Date Fair Value
Unvested at beginning of period (in dollars per share)		$ 25.83	$ 29.16
Granted (in dollars per share)		26.67	21.05
Vested (in dollars per share)		30.73	29.53
Forfeited (in dollars per share)		30.73	29.53
Unvested at end of period (in dollars per share)		$ 24.68	$ 25.83
Unrecognized compensation
Unrecognized compensation costs		$ 99,000
Unrecognized compensation costs, period of recognition		3 years
Restricted Stock Units Based on a Performance Condition | 2019 Equity Incentive Plan
Restricted Stock Awards
Granted (in shares)		13,016
Unrecognized compensation
Vesting period		3 years
Restricted Stock Units Based on a Performance Condition | Minimum
Unrecognized compensation
Shares vesting as a percentage of target		0.00%
Restricted Stock Units Based on a Performance Condition | Maximum
Unrecognized compensation
Shares vesting as a percentage of target		150.00%
Restricted Stock Units Based on a Market Condition
Restricted Stock Awards
Unvested at beginning of period (in shares)		10,147	8,994
Granted (in shares)		3,254	4,032
Vested (in shares)		1,628	1,197
Forfeited (in shares)		1,377	1,682
Unvested at end of period (in shares)		10,396	10,147
Weighted Average Grant Date Fair Value
Unvested at beginning of period (in dollars per share)		$ 24.69	$ 25.74
Granted (in dollars per share)		25.94	22.16
Vested (in dollars per share)		28.32	24.44
Forfeited (in dollars per share)		28.32	22.44
Unvested at end of period (in dollars per share)		$ 24.03	$ 24.69
Unrecognized compensation
Unrecognized compensation costs		$ 85,000
Unrecognized compensation costs, period of recognition		3 years
Restricted Stock Units Based on a Market Condition | 2019 Equity Incentive Plan
Restricted Stock Awards
Granted (in shares)		3,254
Unrecognized compensation
Vesting period		3 years
Assumptions used in the Monte Carlo valuation of PRSUs
Term used for risk-free rate	2 years 8 months 26 days
Term used for risk-free rate and historical volatility	2 years 8 months 26 days
Risk-free interest rate (as a percent)	0.32%
Closing stock price (in dollars per share)	$ 26.77			$ 24.03
Annualized volatility (as a percent)	38.50%

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share
Net income	$ 4,162	$ 4,318	$ 13,233	$ 13,082
Income allotted to participating securities	(23)	(23)	(47)	(47)
Net income available to common shareholders	$ 4,139	$ 4,295	$ 13,186	$ 13,035
Weighted-average number of shares used in:
Basic earnings per share (in shares)	9,012,398	9,104,079	9,086,447	9,144,463
Dilutive common stock equivalents:
Stock options and restricted stock units (in shares)	44,171	30,010	44,622	57,419
Diluted earnings per share (in shares)	9,056,569	9,134,089	9,131,069	9,201,882
Net income per common share, basic (in dollars per share)	$ 0.46	$ 0.47	$ 1.45	$ 1.43
Net income per common share, diluted (in dollars per share)	$ 0.46	$ 0.47	$ 1.44	$ 1.42

Other Comprehensive Income an_3

Other Comprehensive Income and Loss - Changes in Components of Accumulated Other Comprehensive Income and Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Changes in the components of accumulated other comprehensive loss, net of taxes
Balances at beginning of period	$ (251,245)	$ (244,027)	$ (248,708)	$ (243,890)
Other comprehensive (income) loss, net of taxes		4	276	199
Net current period other comprehensive loss		4	276	199
Balances at end of period	(251,689)	(246,658)	(251,689)	(246,658)
Accumulated Other Comprehensive Loss
Changes in the components of accumulated other comprehensive loss, net of taxes
Balances at beginning of period	8,967	7,863	8,691	7,668
Net current period other comprehensive loss	0	4	276	199
Balances at end of period	8,967	7,867	8,967	7,867
Unfunded Pension Liability
Changes in the components of accumulated other comprehensive loss, net of taxes
Balances at beginning of period	8,967	8,178	8,967	8,178
Net current period other comprehensive loss	0
Balances at end of period	8,967	8,178	8,967	8,178
Unrealized (gain) loss on securities
Changes in the components of accumulated other comprehensive loss, net of taxes
Balances at beginning of period		(315)	(276)	(510)
Other comprehensive (income) loss, net of taxes		4	3	(22)
Net current period other comprehensive loss	$ 0	4	276	199
Balances at end of period		(311)		(311)
Other comprehensive (income) loss, net of taxes
Changes in the components of accumulated other comprehensive loss, net of taxes
Other comprehensive (income) loss, net of taxes		$ 4	3	(22)
Amount Reclassified from Other Comprehensive Income
Changes in the components of accumulated other comprehensive loss, net of taxes
Other comprehensive (income) loss, net of taxes			273	221
Amounts reclassified from other comprehensive income, net of taxes			$ (273)	$ (221)

Other Comprehensive Income an_4

Other Comprehensive Income and Loss - Tax Effect on Each Component (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Tax effect on each component of other comprehensive loss
Pretax amount		$ 377	$ 271
Tax		(101)	(72)
After Tax Amount	$ 4	276	199
Unrealized (gain) loss on securities
Tax effect on each component of other comprehensive loss
Pretax amount	5	4	(30)
Tax	(1)	(1)	8
After Tax Amount	$ 4	3	(22)
Amount Reclassified from Other Comprehensive Income
Tax effect on each component of other comprehensive loss
Pretax amount		373	301
Tax		(100)	(80)
After Tax Amount		$ 273	$ 221

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues
Revenue from contracts with customers	$ 429	$ 750	$ 2,009	$ 1,727
Other revenue	61	41	186	160
Total other noninterest income	57	63	237	171
Total revenue from contracts with customers and other revenue	490	791	2,195	1,887
Service Fees on Loan and Deposit Accounts
Revenues
Revenue from contracts with customers	399	715	1,855	1,639
Other revenue	34	13	103	77
Total	433	728	1,958	1,716
Other
Revenues
Revenue from contracts with customers	30	35	154	88
Other revenue	27	28	83	83
Total other noninterest income	$ 57	$ 63	$ 237	$ 171

Leases - Lease Costs (Details)

Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lease costs:
Operating lease costs	$ 843	$ 878	$ 2,552	$ 2,509
Short-term lease costs	15	5	32	17
Variable lease costs	31	38	113	115
Total lease costs	889	921	2,697	2,641
Cash paid for amounts included in measurement of lease liabilities	836	808	2,520	2,414
Establishment of right-of-use asset, net of incentives	$ 444	$ 2,247	$ 3,285	$ 4,033

Leases - Future Minimum Rental

Leases - Future Minimum Rental Commitments Under Non-cancellable Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Future minimum rental commitments:
2021	$ 801
2022	3,048
2023	2,697
2024	2,441
2025	1,740
Thereafter	4,264
Total	14,991
Less present value discount	(872)
Present value of leases	$ 14,119	$ 13,119

Leases - Other Related Informat

Leases - Other Related Information (Details)	Sep. 30, 2021	Sep. 30, 2020
Leases
Weighted-average remaining lease term (years)	5 years 11 months 12 days	6 years
Weighted-average discount rate	2.18%	2.45%

Fair Value - Estimated Fair Val

Fair Value - Estimated Fair Values (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Investment securities available for sale, at fair value		$ 3,562
Investment securities held to maturity	$ 623,406	262,841
Carrying Amount
Assets
Cash and cash equivalents	101,386	363,543
Investment securities available for sale, at fair value		3,562
Investment securities held to maturity	621,417	247,642
Loans held for sale	488	2,195
Loans receivable, net	1,303,969	1,406,995
FHLB stock	8,173	8,144
FRB stock	3,158	3,145
Accrued interest receivable	6,070	6,515
Interest rate contracts	209	38
Liabilities
Deposits	1,664,963	1,659,800
Advances from the Federal Home Loan Bank	141,000	141,000
Securities sold under agreements to repurchase	10,000	10,000
Accrued interest payable	52	35
Interest rate contracts	209	38
Estimated Fair Value
Assets
Cash and cash equivalents	101,386	363,543
Investment securities available for sale, at fair value		3,562
Investment securities held to maturity	623,406	262,841
Loans held for sale	489	2,274
Loans receivable, net	1,362,554	1,433,489
FHLB stock	8,173	8,144
FRB stock	3,158	3,145
Accrued interest receivable	6,070	6,515
Interest rate contracts	209	38
Liabilities
Deposits	1,666,163	1,663,226
Advances from the Federal Home Loan Bank	143,498	145,441
Securities sold under agreements to repurchase	10,279	10,466
Accrued interest payable	52	35
Interest rate contracts	209	38
Estimated Fair Value | Level 1
Assets
Cash and cash equivalents	101,386	363,543
Accrued interest receivable	18	16
Estimated Fair Value | Level 2
Assets
Investment securities available for sale, at fair value		3,562
Investment securities held to maturity	623,406	262,841
Loans held for sale	489	2,274
FHLB stock	8,173	8,144
FRB stock	3,158	3,145
Accrued interest receivable	1,159	627
Interest rate contracts	209	38
Liabilities
Deposits	1,429,153	1,338,022
Advances from the Federal Home Loan Bank	143,498	145,441
Securities sold under agreements to repurchase	10,279	10,466
Accrued interest payable	50	33
Interest rate contracts	209	38
Estimated Fair Value | Level 3
Assets
Loans receivable, net	1,362,554	1,433,489
Accrued interest receivable	4,893	5,872
Liabilities
Deposits	237,010	325,204
Accrued interest payable	$ 2	$ 2

Fair Value - Recurring Basis (D

Fair Value - Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets and Liabilities Measured at Fair Value on Recurring Basis
Investment securities available for sale, at fair value		$ 3,562
Fair Value, Measurements, Recurring
Assets and Liabilities Measured at Fair Value on Recurring Basis
Interest rate contracts - assets	$ 209	38
Interest rate contracts - liabilities	(209)	(38)
Investment securities available for sale, at fair value		3,562
Fair Value, Measurements, Recurring | Level 2
Assets and Liabilities Measured at Fair Value on Recurring Basis
Interest rate contracts - assets	209	38
Interest rate contracts - liabilities	$ (209)	(38)
Investment securities available for sale, at fair value		$ 3,562

Fair Value - Nonrecurring Basis

Fair Value - Nonrecurring Basis (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2021USD ($)
Level 3
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Valuation Technique [Extensible List]	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair Value, Measurements, Nonrecurring
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Fair value		$ 0
Liabilities measured at fair value	$ 0	$ 0
Fair Value, Measurements, Nonrecurring | Mortgage Servicing Assets
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Mortgage servicing assets, Fair value	407
Mortgage servicing assets, Total losses	(73)
Fair Value, Measurements, Nonrecurring | Level 3 | Mortgage Servicing Assets
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Mortgage servicing assets, Fair value	$ 407
Discount rate | Fair Value, Measurements, Nonrecurring | Level 3 | Mortgage Servicing Assets
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Measurement Input	10.25
Prepayment speed (CPR) | Fair Value, Measurements, Nonrecurring | Level 3
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Measurement Input	(13.57)
Annual cost to service (per loan, in dollars) | Fair Value, Measurements, Nonrecurring | Level 3
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Measurement Input	75
Discounted cash flow model | Fair Value, Measurements, Nonrecurring | Level 3 | Mortgage Servicing Assets
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Fair value	$ 407
Minimum | Discount rate | Fair Value, Measurements, Nonrecurring | Level 3 | Mortgage Servicing Assets
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Measurement Input	9.25
Minimum | Prepayment speed (CPR) | Fair Value, Measurements, Nonrecurring | Level 3
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Measurement Input	10.42
Maximum | Discount rate | Fair Value, Measurements, Nonrecurring | Level 3 | Mortgage Servicing Assets
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Measurement Input	11.25
Maximum | Prepayment speed (CPR) | Fair Value, Measurements, Nonrecurring | Level 3
Assets Measured at Fair Value on Nonrecurring Basis and Related Losses
Servicing Asset, Measurement Input	19.61

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)	Oct. 28, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Subsequent Events
Quarterly cash dividend declared on common stock (in dollars per share)		$ 0.23	$ 0.23	$ 0.69	$ 0.69
Subsequent event
Subsequent Events
Quarterly cash dividend declared on common stock (in dollars per share)	$ 0.23
Tenth share repurchase program	$ 5,000,000