FS Bancorp (FSBW) 10-K 16 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 05, 2021	Jun. 30, 2020
Document And Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
Entity File Number	001-35589
Entity Registrant Name	FS BANCORP, INC.
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	45-4585178
Entity Address, Address Line One	6920 220th Street SW
Entity Address, City or Town	Mountlake Terrace
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98043
City Area Code	425
Local Phone Number	771-5299
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	FSBW
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	true
Entity Common Stock, Shares Outstanding		4,233,040
Entity Public Float			$ 147,557,403
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0001530249
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Cash and due from banks	$ 11,554	$ 13,175
Interest-bearing deposits at other financial institutions	80,022	32,603
Total cash and cash equivalents	91,576	45,778
Certificates of deposit at other financial institutions	12,278	20,902
Securities available-for-sale, at fair value	178,018	126,057
Securities held-to-maturity (fair value of $7,556)	7,500	0
Loans held for sale, at fair value	166,448	69,699
Loans receivable, net	1,544,981	1,336,346
Accrued interest receivable	7,030	5,908
Premises and equipment, net	27,343	28,770
Operating lease right-of-use ("ROU") assets	4,949	5,016
Federal Home Loan Bank ("FHLB") stock, at cost	7,439	8,045
Other real estate owned ("OREO")	90	168
Bank owned life insurance ("BOLI"), net	36,226	35,356
Servicing rights, held at the lower of cost or fair value	12,595	11,560
Goodwill	2,312	2,312
Core deposit intangible, net	4,751	5,457
Other assets	9,705	11,682
TOTAL ASSETS	2,113,241	1,713,056
LIABILITIES
Noninterest-bearing accounts	362,853	273,602
Interest-bearing accounts	1,311,218	1,118,806
Total deposits	1,674,071	1,392,408
Borrowings	165,809	84,864
Principal amount	10,000	10,000
Unamortized debt issuance costs		(115)
Total subordinated note less unamortized debt issuance costs	10,000	9,885
Operating lease liabilities	5,176	5,214
Deferred tax liability, net	58	1,971
Other liabilities	28,120	18,472
Total liabilities	1,883,234	1,512,814
COMMITMENTS AND CONTINGENCIES (NOTE 12)
STOCKHOLDERS' EQUITY
Preferred stock, $.01 par value; 5,000,000 shares authorized; none issued or outstanding
Common stock, $.01 par value; 45,000,000 shares authorized; 4,237,956 and 4,459,041 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively	42	44
Additional paid-in capital	81,318	89,268
Retained earnings	146,405	110,715
Accumulated other comprehensive income, net of tax	2,533	788
Unearned shares - Employee Stock Ownership Plan ("ESOP")	(291)	(573)
Total stockholders' equity	230,007	200,242
Total liabilities and stockholders' equity	$ 2,113,241	$ 1,713,056

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Items included in Consolidated Statement of Financial Position [Abstract]
Securities held-to-maturity, at fair value	$ 7,556
Preferred stock par value, in dollars per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
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, shares authorized	45,000,000	45,000,000
Common stock, shares issued	4,237,956	4,459,041
Common stock, shares outstanding	4,237,956	4,459,041

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
INTEREST INCOME
Loans receivable, including fees	$ 84,128,000	$ 84,706,000
Interest and dividends on investment securities, cash and cash equivalents, and certificates of deposit at other financial institutions	4,709,000	4,919,000
Total interest and dividend income	88,837,000	89,625,000
INTEREST EXPENSE
Deposits	11,980,000	16,162,000
Borrowings	1,961,000	2,476,000
Subordinated note	776,000	679,000
Total interest expense	14,717,000	19,317,000
NET INTEREST INCOME	74,120,000	70,308,000
PROVISION FOR LOAN LOSSES	13,036,000	2,880,000
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	61,084,000	67,428,000
NONINTEREST INCOME
Service charges and fee income	2,373,000	6,554,000
Gain on sale of loans	48,842,000	14,248,000
Loss on disposed fixed assets		(26,000)
Gain on sale of investment securities	300,000	32,000
Earnings on cash surrender value of BOLI	870,000	872,000
Other noninterest income	2,974,000	1,355,000
Total noninterest income	55,359,000	23,035,000
NONINTEREST EXPENSE
Salaries and benefits	38,095,000	33,816,000
Operations	10,471,000	9,722,000
Occupancy	4,736,000	4,640,000
Data processing	4,388,000	4,972,000
Loss (gain) on sale of OREO	2,000	(138,000)
OREO expenses	4,000	13,000
Loan costs	2,066,000	3,238,000
Professional and board fees	2,797,000	2,426,000
Federal Deposit Insurance Corporation ("FDIC") insurance	829,000	358,000
Marketing and advertising	530,000	678,000
Acquisition costs	0	1,756,000
Amortization of core deposit intangible	706,000	760,000
Impairment of servicing rights	1,969,000	92,000
Total noninterest expense	66,593,000	62,333,000
INCOME BEFORE PROVISION FOR INCOME TAXES	49,850,000	28,130,000
PROVISION FOR INCOME TAXES	10,586,000	5,413,000
NET INCOME	$ 39,264,000	$ 22,717,000
Basic earnings per share(in dollars per share)	$ 9.14	$ 5.13
Diluted earnings per share(in dollars per share)	$ 8.97	$ 5.01

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 39,264	$ 22,717
Securities available-for-sale:
Unrealized holding gain during period	3,754	2,920
Income tax provision related to unrealized holding gain	(807)	(628)
Reclassification adjustment for realized gains, net included in net income	(300)	(32)
Income tax provision related to reclassification for realized gains, net	65	7
Cash flow hedges:
Unrealized derivative losses during period	(1,429)
Income tax benefit related to unrealized derivative losses	307
Reclassification adjustment for interest expense, net included in net income	198
Income tax provision related to reclassification for expense, net	(43)
Other comprehensive income, net of tax	1,745	2,267
COMPREHENSIVE INCOME	$ 41,009	$ 24,984

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income, Net of Tax	Unearned ESOP Shares	Total
Balance at Dec. 31, 2018	$ 45	$ 91,466	$ 90,854	$ (1,479)	$ (848)	$ 180,038
Balance (in shares) at Dec. 31, 2018	4,492,478
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			22,717			22,717
Dividends paid			(2,856)			(2,856)
Share-based compensation		869				869
Restricted stock awards (in shares)	20,215
Common stock repurchased	$ (1)	(4,799)				(4,800)
Common stock repurchased (in shares)	(102,384)
Common stock repurchased for employee/director taxes paid on restricted stock awards		(204)				(204)
Common stock repurchased for employee/director taxes paid on restricted stock awards (in shares)	(4,037)
Stock options exercised, net		705				705
Stock options exercised, net (in shares)	52,769
Other comprehensive income, net of tax				2,267		2,267
ESOP shares allocated		1,231			275	1,506
Balance at Dec. 31, 2019	$ 44	89,268	110,715	788	(573)	200,242
Balance (in shares) at Dec. 31, 2019	4,459,041
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			39,264			39,264
Dividends paid			(3,574)			(3,574)
Share-based compensation		1,020				1,020
Restricted stock awards	$ 1					1
Restricted stock awards (in shares)	24,880
Common stock repurchased	$ (3)	(9,799)				(9,802)
Common stock repurchased (in shares)	(259,543)
Common stock repurchased for employee/director taxes paid on restricted stock awards		(35)				(35)
Common stock repurchased for employee/director taxes paid on restricted stock awards (in shares)	(820)
Stock options exercised, net		(161)				(161)
Stock options exercised, net (in shares)	14,398
Other comprehensive income, net of tax				1,745		1,745
ESOP shares allocated		1,025			282	1,307
Balance at Dec. 31, 2020	$ 42	$ 81,318	$ 146,405	$ 2,533	$ (291)	$ 230,007
Balance (in shares) at Dec. 31, 2020	4,237,956

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Statement of Stockholders' Equity [Abstract]
Dividends paid (in dollars per share)	$ 0.84	$ 0.65

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS (USED BY) FROM OPERATING ACTIVITIES
Net income	$ 39,264	$ 22,717
Adjustments to reconcile net income to net cash from operating activities
Provision for loan losses	13,036	2,880
Depreciation, amortization and accretion	13,618	12,003
Compensation expense related to stock options and restricted stock awards	1,020	869
ESOP compensation expense for allocated shares	1,307	1,506
(Benefit) provision for deferred income taxes	(2,390)	988
Increase in cash surrender value of BOLI	(870)	(872)
Gain on sale of loans held for sale	(48,842)	(14,126)
Gain on sale of portfolio loans		(122)
Gain on sale of investment securities	(300)	(32)
Loss on disposed fixed assets		26
Origination of loans held for sale	(1,730,665)	(804,619)
Proceeds from sale of loans held for sale	1,670,431	795,184
Impairment of servicing rights	1,969	92
Loss (gain) on sale of OREO	2	(138)
Changes in operating assets and liabilities
Accrued interest receivable	(1,122)	(147)
Other assets	5,511	(4,589)
Other liabilities	5,714	(2,443)
Net cash (used by) from operating activities	(32,317)	9,177
Activity in securities available-for-sale:
Proceeds from sale of investment securities	12,214	10,554
Maturities, prepayments, and calls	37,964	24,293
Purchases	(99,390)	(61,282)
Maturities of certificates of deposit at other financial institutions	8,624	3,650
Activity in securities held-to-maturity:
Purchases	7,500
Purchase of certificates of deposit at other financial institutions		(2,480)
Loan originations and principal collections, net	(189,162)	(36,904)
Purchase of portfolio loans	(32,743)	(1,799)
Proceeds from sale of portfolio loans		8,487
Proceeds from sale of OREO, net	76	901
Purchase of premises and equipment, net	(1,379)	(2,463)
Change in FHLB stock, net	606	1,842
Net cash used by investing activities	(270,690)	(55,201)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposits	281,431	118,714
Proceeds from borrowings	601,158	401,447
Repayments of borrowings	(520,213)	(453,983)
Dividends paid on common stock	(3,574)	(2,856)
(Disbursements) proceeds from stock options exercised, net	(161)	705
Common stock repurchased for employee/director taxes paid on restricted stock awards	(34)	(204)
Common stock repurchased	(9,802)	(4,800)
Net cash from financing activities	348,805	59,023
NET INCREASE IN CASH AND CASH EQUIVALENTS	45,798	12,999
CASH AND CASH EQUIVALENTS, beginning of year	45,778	32,779
CASH AND CASH EQUIVALENTS, end of year	91,576	45,778
Cash paid during the period for:
Interest on deposits and borrowings	14,584	18,709
Income taxes	11,685	4,351
SUPPLEMENTARY DISCLOSURES OF NONCASH OPERATING, INVESTING AND FINANCING ACTIVITIES
Change in unrealized gain on investment securities, net	3,454	2,888
Change in unrealized loss on cash flow hedges, net	(1,231)
Retention in gross mortgage servicing rights from loan sales	11,139	5,400
Property taken in settlement of loans		312
Right-of-use assets in exchange for lease liabilities	$ 1,202	$ 6,232

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Basis of Presentation and Summary of Significant Accounting Policies
Basis of Presentation and Summary of Significant Accounting Policies	NOTE 1 - BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations - a Financial Statement Presentation - Amounts presented in the consolidated financial statements and footnote tables are rounded and presented to the nearest thousands of dollars except per share amounts. If the amounts are above $1.0 million, they are rounded one decimal point, and if they are above $1.0 billion, they are rounded two decimal points. Principles of Consolidation - Segment Reporting - Subsequent Events - Cash and Cash Equivalents - Securities - non-contingently callable debt securities which are amortized to the earliest call date, rather than the contractual maturity date. ​ Unrealized holding gains and losses, net of the related deferred tax effect, are reported as a net amount in a separate component of equity entitled accumulated other comprehensive income (loss). Any declines in the values of these securities that are considered to be other-than-temporary-impairment (“OTTI”) and credit-related are recognized in earnings. Noncredit-related OTTI on securities not expected to be sold is recognized in other comprehensive income (loss). The review for OTTI is conducted on an ongoing basis and takes into account the severity and duration of the impairment, recent events specific to the issuer or industry, fair value in relationship to cost, extent and nature of change in fair value, creditworthiness of the issuer including external credit ratings and recent downgrades, trends and volatility of earnings, current analysts’ evaluations, and other key measures. In addition, the Company does not intend to sell the securities and it is more likely than not that we will not be required to sell the securities before recovery of their amortized cost basis. In doing this, we take into account our balance sheet management strategy and consideration of current and future market conditions. Dividends and interest income are recognized when earned. Federal Home Loan Bank Stock - Management evaluates FHLB stock for impairment as needed. Management’s determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. The determination of whether a decline affects the ultimate recoverability of cost is influenced by criteria such as (1) the significance of any decline in net assets of the FHLB as compared with the capital stock amount for the FHLB and the length of time this situation has persisted; (2) commitments by the FHLB to make payments required by law or regulation and the level of such payments in relation to the operating performance of the FHLB; (3) the impact of legislative and regulatory changes on institutions and, accordingly, the customer base of the FHLB; and (4) the liquidity position of the FHLB. Based on its evaluation, management determined that there was no impairment of FHLB stock at December 31, 2020 and 2019, respectively. Loans Held for Sale - ​ Other Real Estate Owned - ​ Derivatives - The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and resulting designation. The Company’s hedging policies permit the use of various derivative financial instruments to manage interest rate risk or to hedge specified assets and liabilities. To qualify for hedge accounting, derivatives must be highly effective at reducing the risk associated with the exposure being hedged and must be designated as a hedge at the inception of the derivative contract. If derivative instruments are designated as fair value hedges, and such hedges are highly effective, both the change in the fair value of the hedge and the hedged item are included in current earnings. If derivative instruments are designated as cash flow hedges, fair value adjustments related to the effective portion are recorded in other comprehensive income and are reclassified to earnings when the hedged transaction is reflected in earnings. Ineffective portions of cash flow hedges are reflected in earnings as they occur. Actual cash receipts and/or payments and related accruals on derivatives related to hedges are recorded as adjustments to the interest income or interest expense associated with the hedged item. During the life of the hedge, the Company formally assesses whether derivatives designated as hedging instruments continue to be highly effective in offsetting changes in the fair value or cash flows of hedged items. If it is determined that a hedge has ceased to be highly effective, the Company will discontinue hedge accounting prospectively. At such time, previous adjustments to the carrying value of the hedged item are reversed into current earnings and the derivative instrument is reclassified to a trading position recorded at fair value. For derivatives not designated as hedges, changes in fair value are recognized in earnings, in noninterest income. ​ Loans Receivable - Interest on loans is accrued daily based on the principal amount outstanding. Generally, the accrual of interest on loans is discontinued when, in management’s opinion, the borrower may be unable to meet payments as they become due or when they are past due 90 days as to either principal or interest (based on contractual terms), unless they are well secured and in the process of collection. All interest accrued but not collected for loans that are placed on nonaccrual status or charged off are reversed against interest income. Subsequent collections on a cash basis are applied proportionately to past due principal and interest, unless collectability of principal is in doubt, in which case all payments are applied to principal. Loans are returned to accrual status when the loan is performing according to its contractual terms for at least six months and the collectability of principal and interest is no longer doubtful. The Company did not designate loans with payment deferrals granted due to the novel coronavirus of 2019 (“COVID-19’) pandemic as delinquent in accordance with provisions of The Coronavirus Aid, Relief, and Economic Security Act of 2020 (the “CARES Act”) and the Consolidated Appropriations Act, 2021 (the “CAA 2021”) and related regulatory guidance. Impaired Loans - The categories of nonaccrual loans and impaired loans overlap, although they are not coextensive. The Company considers all circumstances regarding the loan and borrower on an individual basis when determining whether an impaired loan should be placed on nonaccrual status, such as the financial strength of the borrower, the collateral value, reasons for delay, payment record, the amount of past due and the number of days past due. Loans that experience insignificant payment delays and payment shortfalls are generally not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of shortfall in relation to the principal and interest owed. Troubled Debt Restructured Loans the maturity at an interest rate below current market; a reduction in the face amount of the debt; a reduction in the accrued interest; or re-aging, extensions, deferrals and renewals. TDR loans are considered impaired loans and are individually evaluated for impairment and can be classified as either accrual or nonaccrual. TDR loans are classified as nonperforming loans unless they have been performing in accordance with their modified terms for a period of at least six months in which case they are placed on accrual status. See “ Recent Accounting Pronouncements, Recent Events” below for payment deferrals considered to be short-term that are not considered TDRs. Allowance for Loan and Lease Losses (“ALLL”) - When available information confirms that specific loans or portions thereof are uncollectible, these amounts are charged-off against the ALLL. The existence of some or all of the following criteria will generally confirm that a loss has been incurred: the loan is significantly delinquent and the borrower has not evidenced the ability or intent to bring the loan current; the Company has no recourse to the borrower, or if it does, the borrower has insufficient assets to pay the debt; the estimated fair value of the loan collateral is significantly below the current loan balance, and there is little or no near-term prospect for improvement. A provision for loan losses is charged against income and added to the ALLL based on regular assessment of the loan portfolio. The ALLL is allocated to certain loan categories based on the relative risk characteristics, asset classifications, and actual loss experience within the loan portfolio. Although management has allocated the ALLL to various loan portfolio segments, the allowance is general in nature and is available for the loan portfolio in its entirety. The ultimate recovery of all loans is susceptible to future market factors beyond the Company’s control. These factors may result in losses or recoveries differing significantly from those provided for in the financial statements. In addition, regulatory agencies, as an integral part of their examination process, periodically review the Company’s ALLL, and may require the Company to make additions to the allowance based on their judgment about information available to them at the time of their examinations. Reserve for Unfunded Loan Commitments - Premises and Equipment, Net - three Management reviews buildings, improvements and equipment for impairment on an annual basis or whenever events or changes in the circumstances indicate that the undiscounted cash flows for the property are less than its carrying value. If identified, an impairment loss is recognized through a charge to earnings based on the fair value of the property. Right of Use Lease Asset & Lease Liability - The Company leases retail space, office space, storage space, and equipment under operating leases. Most leases require the Company to pay real estate taxes, maintenance, insurance and other similar costs in addition to the base rent. Certain leases also contain lease incentives, such as tenant improvement allowances and rent abatement. Variable lease payments are recognized as lease expense as they are incurred. The Company records an operating lease right of use (ROU) asset and an operating lease liability (lease liability) for operating leases with a lease term greater than 12 months. The ROU asset and lease liability are recorded in other assets and other liabilities, respectively, in the consolidated statement of financial condition. ​ ROU assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company generally uses its incremental borrowing rate based on the estimated rate of interest for collateralized borrowing over a similar term of the lease payments at commencement date. Many of the Company’s leases contain various provisions for increases in rental rates, based either on changes in the published Consumer Price Index or a predetermined escalation schedule, which are factored into our determination of lease payments when appropriate. Substantially all of the leases provide the Company with the option to extend the lease term one or more times following expiration of the initial term. The ROU asset and lease liability terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. ​ Transfers of Financial Assets - Servicing Rights - Servicing assets are evaluated quarterly for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights into tranches based on predominant characteristics, such as interest rate, loan type, and investor type. Impairment is recognized through a valuation allowance for an individual tranche, to the extent that fair value is less than the capitalized amount for the tranche. If the Company later determines that all or a portion of the impairment no longer exists for a particular tranche, a reduction of the allowance may be recorded as an increase to income. Capitalized servicing rights are stated separately on the Consolidated Balance Sheets and are amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets. Income Taxes - The Company follows the authoritative guidance issued related to accounting for uncertainty in income taxes. The guidance prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. It is the Company’s policy to record any penalties or interest arising from federal or state taxes as a component of income tax expense. Employee Stock Ownership Plan - Earnings Per Share (“EPS”) - Comprehensive Income (Loss) - Financial Instruments - Restricted Assets - Marketing and Advertising Costs - Stock-Based Compensation - Goodwill - Business Combinations In the event that the fair value of net assets acquired exceeds the purchase price, including fair value of liabilities assumed, a bargain purchase gain is recorded on that acquisition. ​ Acquired Loans ​ Application of New Accounting Guidance in 2020 On January 1, 2020, the Company adopted the Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU’) No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement ​ In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ​ RECENT ACCOUNTING PRONOUNCEMENTS In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as amended by ASU 2018-19, ASU 2019-10, and ASU 2019-11. ​ The Company has selected a third-party vendor to assist in the implementation of this ASU and has run parallel computations as it continues to evaluate the impact of adoption of the new standard. As part of the implementation, management is also evaluating economic variables and forecast time horizons it believes to be most relevant based on the composition of the loan portfolio to develop a reasonable and supportable forecast, likely to include forecasted levels of employment, gross domestic product, and home price index, depending on the nature of the loan segment, as well as various loss methodologies to estimate expected credit losses. In addition, management has kept current on evolving interpretations and industry practices related to ASU 2016-13 via webcasts, publications, and conferences. Once adopted, the Company anticipates the allowance for loan losses to potentially increase through a one-time adjustment to retained earnings, however, until the evaluation is complete the magnitude of the potential increase will be unknown. ​ In April 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments In May 2019, the FASB issued ASU 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740), Simplifying the Accounting for Income Taxes ​ In October 2020, the FASB issued ASU 2020-08, Codification Improvements to Subtopic 310-20: Receivables – Nonrefundable Fees and Other Costs ​ Recent Events consumer loans of $392,000. The majority of these modifications involved short-term (e.g. less than six months) extensions and/or interest-only periods. On December 27, 2020, the Consolidated Appropriations Act (“CAA 2021”) was signed into law. Among other purposes, this act provides additional coronavirus emergency response and relief, including extending relief offered under the CARES Act related to troubled debt restructurings as a result of COVID-19 through January 1, 2022 or 60 days after the end of the national emergency declared by the President, whichever is earlier. For additional information, see “Note 3 - Loans Receivable and Allowance for Loan Losses.”

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Investments	NOTE 2 - INVESTMENTS The following tables present the amortized costs, unrealized gains, unrealized losses, and estimated fair values of securities available-for-sale and held-to-maturity at December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ Estimated ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair SECURITIES AVAILABLE-FOR-SALE ​ Cost ​ Gains ​ Losses ​ Values U.S. agency securities ​ $ 7,940 ​ $ 166 ​ $ (1) ​ $ 8,105 Corporate securities ​ 11,885 ​ 54 ​ (939) ​ 11,000 Municipal bonds ​ 69,572 ​ 2,435 ​ (150) ​ 71,857 Mortgage-backed securities ​ 65,722 ​ 2,541 ​ (76) ​ 68,187 U.S. Small Business Administration securities ​ 18,441 ​ 443 ​ (15) ​ 18,869 Total securities available-for-sale ​ ​ 173,560 ​ ​ 5,639 ​ ​ (1,181) ​ ​ 178,018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SECURITIES HELD-TO-MATURITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate securities ​ ​ 7,500 ​ ​ 77 ​ ​ (21) ​ ​ 7,556 Total securities held-to-maturity ​ ​ 7,500 ​ ​ 77 ​ ​ (21) ​ ​ 7,556 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total securities ​ $ 181,060 ​ $ 5,716 ​ $ (1,202) ​ $ 185,574 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ ​ ​ Estimated ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair SECURITIES AVAILABLE-FOR-SALE ​ Cost ​ Gains ​ Losses ​ Values U.S. agency securities ​ $ 8,986 ​ $ 95 ​ $ (15) ​ $ 9,066 Corporate securities ​ 10,525 ​ 52 ​ (7) ​ 10,570 Municipal bonds ​ 20,516 ​ 604 ​ — ​ 21,120 Mortgage-backed securities ​ 62,745 ​ 405 ​ (300) ​ 62,850 U.S. Small Business Administration securities ​ 22,281 ​ 191 ​ (21) ​ 22,451 Total securities available-for-sale ​ $ 125,053 ​ $ 1,347 ​ $ (343) ​ $ 126,057 ​ There were no securities held-to-maturity at December 31, 2019. ​ At December 31, 2020, the Bank had pledged seven securities held at the FHLB of Des Moines with a carrying value of $8.8 million to secure Washington State public deposits of $13.2 million with a $5.3 million collateral requirement by the Washington Public Deposit Protection Commission. At December 31, 2019, the Bank pledged seven securities held at the FHLB of Des Moines with a carrying value of $7.4 million to secure Washington State public deposits of $10.3 million with a $4.0 million collateral requirement. Investment securities that were in an unrealized loss position at December 31, 2020 and 2019 are presented in the following tables, based on the length of time individual securities have been in an unrealized loss position. Management believes that these securities are only temporarily impaired due to changes in market interest rates or the widening of market spreads subsequent to the initial purchase of the securities, and not due to concerns regarding the underlying credit of the issuers or the underlying collateral. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Less than 12 Months ​ 12 Months or Longer ​ Total ​ Fair Unrealized Fair Unrealized Fair Unrealized SECURITIES AVAILABLE-FOR-SALE ​ Value Losses ​ Value Losses ​ Value Losses U.S. agency securities ​ $ 1,986 ​ $ (1) ​ $ — ​ $ — ​ $ 1,986 ​ $ (1) Corporate securities ​ ​ 7,059 ​ ​ (939) ​ ​ — ​ ​ — ​ ​ 7,059 ​ ​ (939) Municipal bonds ​ ​ 8,377 ​ ​ (150) ​ ​ — ​ ​ — ​ ​ 8,377 ​ ​ (150) Mortgage-backed securities ​ 6,903 ​ (65) ​ 3,002 ​ ​ (11) ​ 9,905 ​ (76) U.S. Small Business Administration securities ​ 2,314 ​ (15) ​ — ​ — ​ 2,314 ​ (15) Total securities available-for-sale ​ ​ 26,639 ​ ​ (1,170) ​ ​ 3,002 ​ ​ (11) ​ ​ 29,641 ​ ​ (1,181) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SECURITIES HELD-TO-MATURITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate securities ​ ​ 4,979 ​ ​ (21) ​ ​ — ​ ​ — ​ ​ 4,979 ​ ​ (21) Total securities held-to-maturity ​ ​ 4,979 ​ ​ (21) ​ ​ — ​ ​ — ​ ​ 4,979 ​ ​ (21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 31,618 ​ $ (1,191) ​ $ 3,002 ​ $ (11) ​ $ 34,620 ​ $ (1,202) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ Less than 12 Months ​ 12 Months or Longer ​ Total ​ Fair Unrealized Fair Unrealized Fair Unrealized SECURITIES AVAILABLE-FOR-SALE Value Losses Value Losses Value Losses U.S. agency securities ​ $ 2,977 ​ $ (15) ​ $ — ​ $ — ​ $ 2,977 ​ $ (15) Corporate securities ​ 1,993 ​ (7) ​ — ​ — ​ 1,993 ​ (7) Mortgage-backed securities ​ 12,345 ​ (154) ​ 11,459 ​ (146) ​ 23,804 ​ (300) U.S. Small Business Administration securities ​ 4,395 ​ (21) ​ — ​ — ​ 4,395 ​ (21) Total ​ $ 21,710 ​ $ (197) ​ $ 11,459 ​ $ (146) ​ $ 33,169 ​ $ (343) ​ There were 21 investments with unrealized losses of less than one year and one investment with unrealized losses of more than one year at December 31, 2020. There were 13 investments with unrealized losses of less than one year and 10 investments with unrealized losses of more than one year at December 31, 2019. The unrealized losses associated with these investments are believed to be caused by changing market conditions that are considered to be temporary and the Company does not intend to sell the securities, and it is not likely to be required to sell these securities prior to maturity. Based on the Company’s evaluation of these securities, no OTTI was recorded for the years ended December 31, 2020 and 2019. Additional deterioration in market and economic conditions related to the COVID-19 pandemic, may have an adverse impact on credit quality in the future and result in other-than-temporary impairment charges. The contractual maturities of securities available-for-sale and held-to-maturity at December 31, 2020 and 2019 are listed below. Expected maturities of mortgage-backed securities may differ from contractual maturities because borrowers may have the right to call or prepay the obligations; therefore, these securities are classified separately with no specific maturity date. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ December 31, 2019 SECURITIES AVAILABLE-FOR-SALE Amortized Fair Amortized Fair U.S. agency securities ​ Cost ​ Value ​ Cost ​ Value Due after one year through five years ​ $ 978 ​ $ 1,060 ​ $ 996 ​ $ 1,036 Due after five years through ten years ​ ​ 1,000 ​ ​ 1,036 ​ ​ 3,997 ​ ​ 4,027 Due after ten years ​ ​ 5,962 ​ ​ 6,009 ​ ​ 3,993 ​ ​ 4,003 Subtotal ​ 7,940 ​ 8,105 ​ 8,986 ​ 9,066 Corporate securities ​ ​ ​ ​ Due in one year or less ​ 2,392 ​ 2,433 ​ 5,034 ​ 5,044 Due after one year through five years ​ 3,493 ​ 3,491 ​ 3,491 ​ 3,532 Due after five years through ten years ​ ​ 4,000 ​ ​ 3,676 ​ ​ 2,000 ​ ​ 1,994 Due after ten years ​ ​ 2,000 ​ ​ 1,400 ​ ​ — ​ ​ — Subtotal ​ 11,885 ​ 11,000 ​ 10,525 ​ 10,570 Municipal bonds ​ ​ ​ ​ Due in one year or less ​ 101 ​ 101 ​ — ​ — Due after one year through five years ​ 3,749 ​ 3,980 ​ 3,774 ​ 3,833 Due after five years through ten years ​ 7,994 ​ 8,321 ​ 3,162 ​ 3,307 Due after ten years ​ 57,728 ​ 59,455 ​ 13,580 ​ 13,980 Subtotal ​ 69,572 ​ 71,857 ​ 20,516 ​ 21,120 Mortgage-backed securities ​ ​ ​ ​ Federal National Mortgage Association (“FNMA”) ​ 47,675 ​ 50,005 ​ 42,131 ​ 42,333 Federal Home Loan Mortgage Corporation (“FHLMC”) ​ 11,825 ​ 11,913 ​ 15,250 ​ 15,179 Government National Mortgage Association (“GNMA”) ​ 6,222 ​ 6,269 ​ 5,364 ​ 5,338 Subtotal ​ 65,722 ​ 68,187 ​ 62,745 ​ 62,850 U.S. Small Business Administration securities ​ ​ ​ ​ Due after one year through five years ​ 2,266 ​ 2,353 ​ 1,546 ​ 1,555 Due after five years through ten years ​ ​ 8,097 ​ ​ 8,333 ​ ​ 11,500 ​ ​ 11,598 Due after ten years ​ ​ 8,078 ​ ​ 8,183 ​ ​ 9,235 ​ ​ 9,298 Subtotal ​ ​ 18,441 ​ ​ 18,869 ​ ​ 22,281 ​ ​ 22,451 Total securities available-for-sale ​ ​ 173,560 ​ ​ 178,018 ​ ​ 125,053 ​ ​ 126,057 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SECURITIES HELD-TO-MATURITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Due after five years through ten years ​ ​ 7,500 ​ ​ 7,556 ​ ​ — ​ ​ — Total securities held-to-maturity ​ ​ 7,500 ​ ​ 7,556 ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total securities ​ $ 181,060 ​ $ 185,574 ​ $ 125,053 ​ $ 126,057 ​ The proceeds and resulting gains and losses, computed using specific identification from sales of securities available-for-sale for the years ended December 31, 2020 and 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Proceeds Gross Gains Gross Losses Securities available-for-sale ​ $ 12,214 ​ $ 300 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Proceeds Gross Gains Gross Losses Securities available-for-sale ​ $ 10,554 ​ $ 91 ​ $ (59) ​

Loans Receivable and Allowance

Loans Receivable and Allowance For Loan Losses	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Loans Receivable and Allowance For Loan Losses	NOTE 3 - LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES The composition of the loan portfolio was as follows at December 31: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, REAL ESTATE LOANS ​ 2020 2019 Commercial ​ $ 222,719 ​ $ 210,749 Construction and development ​ 216,975 ​ 179,654 Home equity ​ 43,093 ​ 38,167 One-to-four-family (excludes loans held for sale) ​ 311,093 ​ 261,539 Multi-family ​ 131,601 ​ 133,931 Total real estate loans ​ 925,481 ​ 824,040 CONSUMER LOANS ​ ​ ​ Indirect home improvement ​ 286,020 ​ 254,691 Marine ​ 85,740 ​ 67,179 Other consumer ​ 3,418 ​ 4,340 Total consumer loans ​ 375,178 ​ 326,210 COMMERCIAL BUSINESS LOANS ​ ​ ​ Commercial and industrial ​ 224,476 ​ 140,531 Warehouse lending ​ 49,092 ​ 61,112 Total commercial business loans ​ 273,568 ​ 201,643 Total loans receivable, gross ​ 1,574,227 ​ 1,351,893 Allowance for loan losses ​ (26,172) ​ (13,229) Deferred costs and fees, net ​ ​ (4,017) ​ ​ (3,273) Premiums on purchased loans, net ​ 943 ​ 955 Total loans receivable, net ​ $ 1,544,981 ​ $ 1,336,346 ​ At December 31, 2020, the Bank held approximately $774.8 million in loans that qualify as collateral for FHLB advances, compared to approximately $646.1 million at December 31, 2019. The Bank held approximately $369.2 million in loans that qualify as collateral for an FRB line of credit at December 31, 2020, compared to approximately $318.8 million at December 31, 2019. During the year ended December 31, 2020, the Bank participated in the U.S. Small Business Administration (“SBA”) Paycheck Protection Program (“PPP”), a guaranteed unsecured loan program enacted under the CARES Act to provide near-term relief to help small businesses impacted by COVID-19 sustain operations. PPP loans included in commercial and industrial business loans totaled $62.1 million, all of which are fully guaranteed by the SBA. The Bank expects that the great majority of PPP borrowers will seek full or partial forgiveness of their loan obligations in accordance with the CARES Act. At December 31, 2020, all of the Bank’s PPP loans were pledged as collateral for non-recourse advances under the FRB’s Paycheck Protection Program Liquidity Facility (“PPPLF”). For additional information, see “Note 9 - Debt.” Included in the carrying value of gross loans are net discounts on loans purchased in the Anchor Bank acquisition in November 2018. The remaining net discount on loans acquired was $1.5 million and $2.7 million, on $132.6 million and $198.5 million of gross loans at December 31, 2020 and December 31, 2019, respectively. The Company has defined its loan portfolio into three segments that reflect the structure of the lending function, the Company’s strategic plan and the manner in which management monitors performance and credit quality. The three loan portfolio segments are: (a) Real Estate Loans, (b) Consumer Loans and (c) Commercial Business Loans. Each of these segments is disaggregated into classes based on the risk characteristics of the borrower and/or the collateral type securing the loan. The following is a summary of each of the Company’s loan portfolio segments and classes: Real Estate Loans Commercial Lending. Loans originated by the Company primarily secured by income producing properties, including retail centers, warehouses, and office buildings located in our market areas. Construction and Development Lending Home Equity Lending One-to-Four-Family Real Estate Lending Multi-family Lending Consumer Loans Indirect Home Improvement Marine. Other Consumer. Commercial Business Loans Commercial and Industrial Lending (“C&I”) Warehouse Lending The following tables detail activity in the allowance for loan losses by loan categories for the years shown: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2020 ​ ​ ​ ​ ​ Commercial ​ ​ ​ ​ ALLOWANCE FOR LOAN LOSSES ​ Real Estate ​ Consumer ​ Business ​ Unallocated ​ Total Beginning balance ​ $ 6,206 ​ $ 3,766 ​ $ 3,254 ​ $ 3 ​ $ 13,229 Provision for loan losses ​ 7,622 ​ 3,372 ​ 1,354 ​ 688 ​ 13,036 Charge-offs ​ — ​ (1,101) ​ (22) ​ — ​ (1,123) Recoveries ​ 18 ​ 659 ​ 353 ​ — ​ 1,030 Net recoveries (charge-offs) ​ 18 ​ (442) ​ 331 ​ — ​ (93) Ending balance ​ $ 13,846 ​ $ 6,696 ​ $ 4,939 ​ $ 691 ​ $ 26,172 Period end amount allocated to: ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 15 ​ $ 305 ​ $ 990 ​ $ — ​ $ 1,310 Loans collectively evaluated for impairment ​ 13,831 ​ 6,391 ​ 3,949 ​ 691 ​ 24,862 Ending balance ​ $ 13,846 ​ $ 6,696 ​ $ 4,939 ​ $ 691 ​ $ 26,172 LOANS RECEIVABLE ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 1,280 ​ $ 871 ​ $ 5,610 ​ $ — ​ $ 7,761 Loans collectively evaluated for impairment ​ 924,201 ​ 374,307 ​ 267,958 ​ — ​ 1,566,466 Ending balance ​ $ 925,481 ​ $ 375,178 ​ $ 273,568 ​ $ — ​ $ 1,574,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2019 ​ ​ ​ ​ ​ Commercial ​ ​ ​ ​ ALLOWANCE FOR LOAN LOSSES ​ Real Estate ​ Consumer ​ Business ​ Unallocated ​ Total Beginning balance ​ $ 5,761 ​ $ 3,351 ​ $ 3,191 ​ $ 46 ​ $ 12,349 Provision (recapture) for loan losses ​ 439 ​ 838 ​ 1,646 ​ (43) ​ 2,880 Charge-offs ​ (5) ​ (1,040) ​ (1,583) ​ — ​ (2,628) Recoveries ​ 11 ​ 617 ​ — ​ — ​ 628 Net recoveries (charge-offs) ​ 6 ​ (423) ​ (1,583) ​ — ​ (2,000) Ending balance ​ $ 6,206 ​ $ 3,766 ​ $ 3,254 ​ $ 3 ​ $ 13,229 Period end amount allocated to: ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 15 ​ $ 167 ​ $ — ​ $ — ​ $ 182 Loans collectively evaluated for impairment ​ 6,191 ​ 3,599 ​ 3,254 ​ 3 ​ 13,047 Ending balance ​ $ 6,206 ​ $ 3,766 ​ $ 3,254 ​ $ 3 ​ $ 13,229 LOANS RECEIVABLE ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 2,635 ​ $ 493 ​ $ — ​ $ — ​ $ 3,128 Loans collectively evaluated for impairment ​ 821,405 ​ 325,717 ​ 201,643 ​ — ​ 1,348,765 Ending balance ​ $ 824,040 ​ $ 326,210 ​ $ 201,643 ​ $ — ​ $ 1,351,893 ​ Nonaccrual and Past Due Loans As a result of the negative impact on employment from the COVID-19 pandemic, the Company anticipates higher levels of financial hardship for its customers, which the Company expects will lead to higher levels of forbearance, delinquency and defaults until such time as the economy and employment return to relatively normal levels. The Company has and will continue to assist customers with an array of payment relief programs during periods of financial hardship, including forbearance. Forbearance allows a borrower to temporarily not make scheduled payments or to make smaller than scheduled payments, in each case for a specified period of time. Forbearance does not grant any reduction in the total principal or interest repayment obligation. While a loan is in forbearance status, interest continues to accrue and is repaid over a specified time period when the loan re-enters repayment status. ​ As of December 31, 2020, the amount of loans remaining under payment/relief agreements included commercial real estate loans of $31.2 million, commercial business loans of $12.8 million, a portfolio one-to-four-family loan of $308,000, and consumer loans of $392,000. These loans were classified as current and accruing interest as of December 31, 2020, with the exception of two commercial business loans totaling $4.4 million classified as current and nonaccrual. These modifications were not classified as TDRs at December 31, 2020 in accordance with the CARES Act and related bank agency regulatory guidance. Loan modifications in accordance with the CARES Act and related banking agency regulatory guidance are still subject to an evaluation in regard to determining whether or not a loan is deemed to be impaired. At December 31, 2020 and December 31, 2019, the Company had no TDRs. ​ The following tables provide information pertaining to the aging analysis of contractually past due loans and nonaccrual loans for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ 30-59 60-89 ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ 90 Days ​ Total ​ ​ ​ Total ​ ​ ​ ​ Past ​ Past ​ or More ​ Past ​ ​ ​ Loans ​ Non- REAL ESTATE LOANS ​ Due ​ Due ​ Past Due ​ Due ​ Current ​ Receivable ​ Accrual Commercial ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 222,719 ​ $ 222,719 ​ $ — Construction and development ​ 1,850 ​ — ​ — ​ 1,850 ​ 215,125 ​ 216,975 ​ — Home equity ​ 127 ​ 137 ​ 219 ​ 483 ​ 42,610 ​ 43,093 ​ 636 One-to-four-family ​ 389 ​ 404 ​ 512 ​ 1,305 ​ 309,788 ​ 311,093 ​ 644 Multi-family ​ — ​ — ​ — ​ — ​ 131,601 ​ 131,601 ​ — Total real estate loans ​ 2,366 ​ 541 ​ 731 ​ 3,638 ​ 921,843 ​ 925,481 ​ 1,280 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 683 ​ 331 ​ 325 ​ 1,339 ​ 284,681 ​ 286,020 ​ 826 Marine ​ 28 ​ 77 ​ 22 ​ 127 ​ 85,613 ​ 85,740 ​ 44 Other consumer ​ 73 ​ 22 ​ — ​ 95 ​ 3,323 ​ 3,418 ​ 1 Total consumer loans ​ 784 ​ 430 ​ 347 ​ 1,561 ​ 373,617 ​ 375,178 ​ 871 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ — ​ 1,204 ​ — ​ 1,204 ​ 223,272 ​ 224,476 ​ 5,610 Warehouse lending ​ — ​ — ​ — ​ — ​ 49,092 ​ 49,092 ​ — Total commercial business loans ​ — ​ 1,204 ​ — ​ 1,204 ​ 272,364 ​ 273,568 ​ 5,610 Total loans ​ $ 3,150 ​ $ 2,175 ​ $ 1,078 ​ $ 6,403 ​ $ 1,567,824 ​ $ 1,574,227 ​ $ 7,761 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ 30-59 60-89 ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ 90 Days ​ Total ​ ​ ​ Total ​ ​ ​ ​ Past ​ Past ​ or More ​ Past ​ ​ ​ Loans ​ Non- REAL ESTATE LOANS ​ Due ​ Due ​ Past Due ​ Due ​ Current ​ Receivable ​ Accrual Commercial ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 210,749 ​ $ 210,749 ​ $ 1,086 Construction and development ​ 533 ​ — ​ — ​ 533 ​ 179,121 ​ 179,654 ​ — Home equity ​ 109 ​ — ​ 185 ​ 294 ​ 37,873 ​ 38,167 ​ 190 One-to-four-family ​ 894 ​ 114 ​ 1,150 ​ 2,158 ​ 259,381 ​ 261,539 ​ 1,264 Multi-family ​ — ​ — ​ — ​ — ​ 133,931 ​ 133,931 ​ — Total real estate loans ​ 1,536 ​ 114 ​ 1,335 ​ 2,985 ​ 821,055 ​ 824,040 ​ 2,540 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 692 ​ 227 ​ 147 ​ 1,066 ​ 253,625 ​ 254,691 ​ 468 Marine ​ 15 ​ — ​ — ​ 15 ​ 67,164 ​ 67,179 ​ — Other consumer ​ 71 ​ 2 ​ 20 ​ 93 ​ 4,247 ​ 4,340 ​ 25 Total consumer loans ​ 778 ​ 229 ​ 167 ​ 1,174 ​ 325,036 ​ 326,210 ​ 493 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ — ​ — ​ — ​ — ​ 140,531 ​ 140,531 ​ — Warehouse lending ​ — ​ — ​ — ​ — ​ 61,112 ​ 61,112 ​ — Total commercial business loans ​ — ​ — ​ — ​ — ​ 201,643 ​ 201,643 ​ — Total loans ​ $ 2,314 ​ $ 343 ​ $ 1,502 ​ $ 4,159 ​ $ 1,347,734 ​ $ 1,351,893 ​ $ 3,033 ​ There were no loans 90 days or more past due and still accruing interest at both December 31, 2020 and December 31, 2019. The following tables provide additional information about our impaired loans that have been segregated to reflect loans for which an allowance for loan losses has been provided and loans for which no allowance was provided for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Unpaid ​ ​ ​ ​ WITH NO RELATED ALLOWANCE RECORDED ​ Principal ​ Recorded ​ Related Real estate loans: ​ Balance ​ Investment ​ Allowance Home equity ​ $ 687 ​ $ 636 ​ $ — One-to-four-family ​ ​ 645 ​ ​ 584 ​ ​ — Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ 1,203 ​ 1,203 ​ ​ — ​ ​ ​ 2,535 ​ ​ 2,423 ​ ​ — WITH RELATED ALLOWANCE RECORDED ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-four-family ​ ​ 61 ​ ​ 60 ​ ​ 15 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Indirect ​ ​ 826 ​ ​ 826 ​ ​ 289 Marine ​ ​ 44 ​ ​ 44 ​ ​ 15 Other consumer ​ ​ 1 ​ ​ 1 ​ ​ 1 Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ ​ 4,407 ​ ​ 4,407 ​ ​ 990 ​ ​ ​ 5,339 ​ ​ 5,338 ​ ​ 1,310 Total ​ $ 7,874 ​ $ 7,761 ​ $ 1,310 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Unpaid ​ ​ ​ ​ WITH NO RELATED ALLOWANCE RECORDED ​ Principal ​ Recorded ​ Related Real estate loans: ​ Balance ​ Investment ​ Allowance Commercial ​ $ 1,097 ​ $ 1,086 ​ $ — Home equity ​ ​ 278 ​ ​ 225 ​ ​ — One-to-four-family ​ ​ 1,293 ​ ​ 1,264 ​ ​ — Consumer loans ​ ​ ​ ​ ​ ​ ​ ​ ​ Other consumer ​ ​ 17 ​ ​ 17 ​ ​ — ​ ​ ​ 2,685 ​ 2,592 ​ ​ — WITH RELATED ALLOWANCE RECORDED ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-four-family ​ ​ 61 ​ ​ 60 ​ ​ 15 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Indirect ​ ​ 468 ​ ​ 468 ​ ​ 164 Other consumer ​ ​ 8 ​ ​ 8 ​ ​ 3 ​ ​ ​ 537 ​ ​ 536 ​ ​ 182 Total ​ $ 3,222 ​ $ 3,128 ​ $ 182 ​ The following table presents the average recorded investment in loans individually evaluated for impairment and the interest income recognized and received for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended ​ ​ December 31, 2020 ​ December 31, 2019 WITH NO RELATED ALLOWANCE RECORDED Average Recorded Interest Income Average Recorded Interest Income Real estate loans: ​ Investment ​ Recognized ​ Investment ​ Recognized Commercial ​ $ 996 ​ $ — ​ $ 90 ​ $ 56 Home equity ​ ​ 485 ​ ​ 25 ​ ​ 206 ​ ​ 3 One-to-four-family ​ 954 ​ 17 ​ 1,500 ​ 34 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other consumer ​ ​ 3 ​ ​ — ​ ​ 4 ​ ​ 2 Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ ​ 100 ​ ​ 37 ​ ​ 180 ​ ​ — ​ ​ ​ 2,538 ​ ​ 79 ​ ​ 1,980 ​ ​ 95 WITH AN ALLOWANCE RECORDED ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-four-family ​ ​ 60 ​ ​ — ​ ​ 5 ​ ​ 5 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Indirect ​ ​ 675 ​ ​ 60 ​ ​ 463 ​ ​ 42 Marine ​ ​ 40 ​ ​ 3 ​ ​ 13 ​ ​ — Other consumer ​ ​ 1 ​ ​ — ​ ​ 5 ​ ​ 1 Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ ​ 2,531 ​ ​ 162 ​ ​ 96 ​ ​ — ​ ​ ​ 3,307 ​ ​ 225 ​ ​ 582 ​ ​ 48 Total ​ $ 5,845 ​ $ 304 ​ $ 2,562 ​ $ 143 ​ Credit Quality Indicators As part of the Company’s on-going monitoring of credit quality of the loan portfolio, management tracks certain credit quality indicators including trends related to (i) the risk grading of loans, (ii) the level of classified loans, (iii) net charge-offs, (iv) nonperforming loans and (v) the general economic conditions in the Company’s markets. All loans modified due to COVID-19 are separately monitored and any request for continuation of relief beyond the initial modification will be reassessed at that time to determine if a further modification should be granted and if a downgrade in risk rating is appropriate. The Company utilizes a risk grading matrix to assign a risk grade to its real estate and commercial business loans. Loans are graded on a scale of 1 to 10, with loans in risk grades 1 to 6 considered “Pass” and loans in risk grades 7 to 10 are reported as classified loans in the Company’s allowance for loan loss analysis. A description of the 10 risk grades is as follows: ● Grades 1 and 2 - These grades include loans to very high quality borrowers with excellent or desirable business credit. ● Grade 3 - This grade includes loans to borrowers of good business credit with moderate risk. ● Grades 4 and 5 - These grades include “Pass” grade loans to borrowers of average credit quality and risk. ● Grade 6 - This grade includes loans on management’s “Watch” list and is intended to be utilized on a temporary basis for “Pass” grade borrowers where frequent and thorough monitoring is required due to credit weaknesses and where significant risk-modifying action is anticipated in the near term. ● Grade 7 - This grade is for “Other Assets Especially Mentioned (OAEM)” in accordance with regulatory guidelines and includes borrowers where performance is poor or significantly less than expected. ● Grade 8 - This grade includes “Substandard” loans in accordance with regulatory guidelines which represent an unacceptable business credit where a loss is possible if loan weakness is not corrected. ● Grade 9 - This grade includes “Doubtful” loans in accordance with regulatory guidelines where a loss is highly probable. ● Grade 10 - This grade includes “Loss” loans in accordance with regulatory guidelines for which total loss is expected and when identified are charged off. Consumer, Home Equity, and One-to-Four-Family Real Estate Loans Homogeneous loans are risk rated based upon the Federal Financial Institutions Examination Council’s Uniform Retail Credit Classification and Account Management Policy. Loans classified under this policy at the Company are consumer loans which include indirect home improvement, solar, marine, other consumer, and one-to-four-family first and second liens. Under the Uniform Retail Credit Classification Policy, loans that are current or less than 90 days past due are graded “Pass” and risk graded “4” or “5” internally. Loans that are past due more than 90 days are classified “Substandard” risk graded “8” internally until the loan has demonstrated consistent performance, typically six months of contractual payments. Closed-end loans that are 120 days past due and open-end loans that are 180 days past due are charged off based on the value of the collateral less cost to sell. Management may more conservatively risk rate credits even if paying in accordance with the loan’s repayment terms. Commercial real estate, construction and development, multi-family and commercial business loans are evaluated individually for their risk classification and may be classified as “Substandard” even if current on their loan payment obligations. The following tables summarize risk rated loan balances by category at the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ Special ​ ​ ​ ​ ​ ​ Pass ​ Watch ​ Mention ​ Substandard ​ Doubtful ​ Loss ​ ​ REAL ESTATE LOANS ​ (1 - 5) ​ (6) ​ (7) ​ (8) ​ (9) ​ (10) ​ Total Commercial ​ $ 157,932 ​ $ 60,834 ​ $ 3,013 ​ $ 940 ​ $ — ​ $ — ​ $ 222,719 Construction and development ​ 212,209 ​ 2,917 ​ 1,849 ​ — ​ — ​ — ​ 216,975 Home equity ​ 42,457 ​ — ​ — ​ 636 ​ — ​ — ​ 43,093 One-to-four-family ​ 303,610 ​ 162 ​ 187 ​ 7,134 ​ — ​ — ​ 311,093 Multi-family ​ 131,601 ​ — ​ — ​ — ​ — ​ — ​ 131,601 Total real estate loans ​ 847,809 ​ 63,913 ​ 5,049 ​ 8,710 ​ — ​ — ​ 925,481 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 285,194 ​ — ​ — ​ 826 ​ — ​ — ​ 286,020 Marine ​ 85,696 ​ — ​ — ​ 44 ​ — ​ — ​ 85,740 Other consumer ​ 3,417 ​ — ​ — ​ 1 ​ — ​ — ​ 3,418 Total consumer loans ​ 374,307 ​ — ​ — ​ 871 ​ — ​ — ​ 375,178 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ 190,392 ​ 23,945 ​ 2,073 ​ 8,066 ​ — ​ — ​ 224,476 Warehouse lending ​ 49,092 ​ — ​ — ​ — ​ — ​ — ​ 49,092 Total commercial business loans ​ 239,484 ​ 23,945 ​ 2,073 ​ 8,066 ​ — ​ — ​ 273,568 Total loans receivable, gross ​ $ 1,461,600 ​ $ 87,858 ​ $ 7,122 ​ $ 17,647 ​ $ — ​ $ — ​ $ 1,574,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ ​ Special ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ Watch ​ Mention ​ Substandard ​ Doubtful ​ Loss ​ ​ REAL ESTATE LOANS (1 - 5) (6) (7) (8) (9) (10) Total Commercial ​ $ 203,703 ​ $ 2,274 ​ $ 3,686 ​ $ 1,086 ​ $ — ​ $ — ​ $ 210,749 Construction and development ​ 177,109 ​ 2,545 ​ — ​ — ​ — ​ — ​ 179,654 Home equity ​ 37,942 ​ — ​ 35 ​ 190 ​ — ​ — ​ 38,167 One-to-four-family ​ 259,580 ​ 635 ​ 60 ​ 1,264 ​ — ​ — ​ 261,539 Multi-family ​ 127,792 ​ 6,139 ​ — ​ — ​ — ​ — ​ 133,931 Total real estate loans ​ 806,126 ​ 11,593 ​ 3,781 ​ 2,540 ​ — ​ — ​ 824,040 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 254,223 ​ — ​ — ​ 468 ​ — ​ — ​ 254,691 Marine ​ 67,179 ​ — ​ — ​ — ​ — ​ — ​ 67,179 Other consumer ​ 4,315 ​ — ​ — ​ 25 ​ — ​ — ​ 4,340 Total consumer loans ​ 325,717 ​ — ​ — ​ 493 ​ — ​ — ​ 326,210 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ 125,025 ​ 10,435 ​ 1,442 ​ 3,629 ​ — ​ — ​ 140,531 Warehouse lending ​ 61,112 ​ — ​ — ​ — ​ — ​ — ​ 61,112 Total commercial business loans ​ 186,137 ​ 10,435 ​ 1,442 ​ 3,629 ​ — ​ — ​ 201,643 Total loans receivable, gross ​ $ 1,317,980 ​ $ 22,028 ​ $ 5,223 ​ $ 6,662 ​ $ — ​ $ — ​ $ 1,351,893 ​ At December 31, 2020, there were no TDRs that were modified in the previous 12 months that subsequently defaulted in the reporting year. The Company had no TDRs at December 31, 2020 or 2019. Related Party Loans Certain directors and executive officers or their related affiliates are customers of and have had banking transactions with the Company. Total loans to directors, executive officers, and their affiliates are subject to regulatory limitations. Outstanding loan balances were as follows and were within regulatory limitations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, ​ 2020 2019 Beginning balance ​ $ 3,249 ​ $ 3,325 Additions ​ 581 ​ — Repayments ​ (33) ​ (76) Ending balance ​ $ 3,797 ​ $ 3,249 ​ The aggregate maximum loan balance of extended credit was $4.2 million and $3.6 million at December 31, 2020 and 2019, respectively, and includes the ending balances from the tables above. These loans and lines of credit were made in compliance with applicable laws on substantially the same terms (including interest rates and collateral) as those prevailing at the time for comparable transactions with other persons and do not involve more than the normal risk of collectability.

Servicing Rights

Servicing Rights	12 Months Ended
	Dec. 31, 2020
Fair Value, Off-balance Sheet Risk [Abstract]
Servicing Rights	NOTE 4 - SERVICING RIGHTS Loans serviced for others are not included on the Consolidated Balance Sheets. The unpaid principal balances of permanent loans serviced for others were $2.17 billion and $1.46 billion at December 31, 2020 and 2019, respectively. The following table summarizes servicing rights activity for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended ​ ​ December 31, ​ 2020 2019 Beginning balance ​ $ 11,560 ​ $ 10,429 Additions ​ 11,139 ​ 5,400 Servicing rights amortized ​ (8,135) ​ (4,177) Impairment of servicing rights ​ ​ (1,969) ​ ​ (92) Ending balance ​ $ 12,595 ​ $ 11,560 ​ The fair market value of the servicing rights’ assets was $12.8 million and $13.3 million at December 31, 2020 and December 31, 2019, respectively. Fair value adjustments to servicing rights are mainly due to market-based assumptions associated with discounted cash flows, loan prepayment speeds, and changes in interest rates. A significant change in prepayments of the loans in the servicing portfolio could result in significant changes in the valuation adjustments, thus creating potential volatility in the carrying amount of servicing rights. The following provides valuation assumptions used in determining the fair value of mortgage servicing rights (“MSR”) at the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, ​ At December 31, Key assumptions: 2020 2019 ​ Weighted average discount rate 9.1 % 9.7 % Conditional prepayment rate (“CPR”) 32.6 % 17.1 % Weighted average life in years 3.0 5.1 ​ ​ Key economic assumptions of the current fair value for single family MSR are presented in the table below. Also presented is the sensitivity to market rate changes for the par rate coupon for a conventional one-to-four-family FNMA, FHLMC, GNMA, or FHLB serviced home loan. The table below references a 50 basis point and 100 basis point adverse rate change and the impact on prepayment speeds and discount rates at December 31, 2020 and December 31, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 December 31, 2019 Aggregate portfolio principal balance (1) ​ $ 2,133,473 $ 1,463,732 ​ Weighted average rate of note ​ ​ 3.5 % ​ 4.2 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2020 Base 0.5% Adverse Rate Change 1.0% Adverse Rate Change ​ Conditional prepayment rate ​ 32.6 % ​ 40.6 % ​ 59.6 % Fair value MSR ​ $ 12,833 $ 10,922 $ 8,286 ​ Percentage of MSR ​ 0.6 % 0.5 % 0.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 9.1 % 9.6 % 10.1 % Fair value MSR ​ $ 12,833 $ 12,696 $ 12,562 ​ Percentage of MSR ​ 0.6 % 0.6 % 0.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2019 ​ Base 0.5% Adverse Rate Change 1.0% Adverse Rate Change ​ Conditional prepayment rate ​ 17.1 % ​ 24.6 % ​ 32.5 % Fair value MSR ​ $ 13,255 $ 10,582 $ 8,674 ​ Percentage of MSR ​ 0.9 % 0.7 % 0.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 9.7 % 10.2 % 10.7 % Fair value MSR ​ $ 13,255 $ 13,037 $ 12,826 ​ Percentage of MSR ​ 0.9 % 0.9 % 0.9 % _______________________________ (1) Excludes nonperforming serviced loans in forbearance. ​ These sensitivities are hypothetical and should be used with caution as the tables above demonstrate the Company’s methodology for estimating the fair value of MSR which is highly sensitive to changes in key assumptions. For example, actual prepayment experience may differ and any difference may have a material effect on MSR fair value. Changes in fair value resulting from changes in assumptions generally cannot be extrapolated because the relationship of the change in the assumption to the change in fair value may not be linear. Also, in these tables, the effects of a variation in a particular assumption on the fair value of the MSR is calculated without changing any other assumption; in reality, changes in one factor may be associated with changes in another (for example, decreases in market interest rates may provide an incentive to refinance; however, this may also indicate a slowing economy and an increase in the unemployment rate, which reduces the number of borrowers who qualify for refinancing), which may magnify or counteract the sensitivities. Thus, any measurement of MSR fair value is limited by the conditions existing and assumptions made at a particular point in time. Those assumptions may not be appropriate if they are applied to a different point in time. The Company recorded $4.4 million and $3.5 million of gross contractually specified servicing fees, late fees, and other ancillary fees resulting from servicing of loans for the years ended December 31, 2020 and 2019, respectively. The income, net of amortization, or reduction in income, if MSR amortization is greater than servicing fees, is reported in noninterest income on the Consolidated Statements of Income.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Premises and Equipment	NOTE 5 - PREMISES AND EQUIPMENT Premises and equipment at December 31, 2020 and 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Land ​ $ 5,227 ​ $ 5,227 Buildings ​ 16,769 ​ 16,769 Furniture, fixtures, and equipment ​ 14,724 ​ 13,562 Leasehold improvements ​ 2,859 ​ 2,848 Building improvements ​ 6,830 ​ 6,572 Projects in process ​ 355 ​ 407 Subtotal ​ 46,764 ​ 45,385 Less accumulated depreciation and amortization ​ (19,421) ​ (16,615) Total ​ $ 27,343 ​ $ 28,770 ​ Depreciation and amortization expense for these assets totaled $2.8 million for both years ended December 31, 2020 and 2019, respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	NOTE 6 - LEASES The Company has operating leases for retail bank and home lending branches, and certain equipment. The Company’s leases have remaining lease terms of five months to nine and a half years ​ ​ The components of lease cost (included in occupancy expense on the Consolidated Statements of Income) are as follows for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended Lease cost: December 31, 2020 December 31, 2019 Operating lease cost ​ $ 1,393 ​ $ 1,285 Short-term lease cost ​ 11 ​ 166 Total lease cost ​ $ 1,404 ​ $ 1,451 ​ The following table provides supplemental information related to operating leases at or for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the ​ At or For the Cash paid for amounts included in the ​ Year Ended ​ Year Ended measurement of lease liabilities: December 31, 2020 December 31, 2019 Operating cash flows from operating leases ​ $ 1,365 ​ ​ $ 1,331 ​ Weighted average remaining lease term- operating leases ​ ​ 5.4 years ​ 5.3 years Weighted average discount rate- operating leases ​ ​ 2.48 % ​ 3.00 % ​ The Company’s leases typically do not contain a discount rate implicit in the lease contract. As an alternative, the discount rate used in determining the lease liability for each individual lease was the FHLB of Des Moines’ fixed advance rate. Maturities of operating lease liabilities at December 31, 2020 for future periods are as follows: ​ ​ ​ ​ ​ ​ ​ ​ 2021 $ 1,319 2022 ​ 1,222 2023 ​ 839 2024 ​ ​ 787 2025 ​ ​ 478 Thereafter ​ 949 Total lease payments ​ ​ 5,594 Less imputed interest ​ ​ (418) Total ​ $ 5,176 ​

Other Real Estate Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2020
Banking and Thrift [Abstract]
Other Real Estate Owned	NOTE 7 - OTHER REAL ESTATE OWNED The following table presents the activity related to OREO at and for the years ended December 31: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended ​ ​ December 31, ​ 2020 2019 Beginning balance ​ $ 168 ​ $ 689 Additions ​ — ​ 242 Gross proceeds from sale of OREO ​ (76) ​ (901) (Loss) gain on sale of OREO ​ (2) ​ 138 Ending balance ​ $ 90 ​ $ 168 ​ There was one OREO property in the amount of $90,000 at December 31, 2020, and two OREO properties totaling $168,000 at December 31, 2019. Holding costs were $4,000 and $13,000 for the years ended December 31, 2020 and 2019, respectively. There were $662,000 and $1.0 million in mortgage loans collateralized by residential real estate property in the process of foreclosure at December 31, 2020, and 2019, respectively.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2020
Banking and Thrift [Abstract]
Deposits	NOTE 8 - DEPOSITS Deposits are summarized as follows at December 31: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2020 2019 Noninterest-bearing checking ​ $ 348,421 ​ $ 260,131 Interest-bearing checking ​ 226,282 ​ 177,972 Savings ​ 152,842 ​ 118,845 Money market ​ 429,548 ​ 270,489 Certificates of deposit less than $100,000 ​ 299,157 ​ 277,988 Certificates of deposit of $100,000 through $250,000 ​ 135,901 ​ 181,402 Certificates of deposit of $250,000 and over ​ 67,488 ​ 92,110 Escrow accounts related to mortgages serviced ​ 14,432 ​ 13,471 Total ​ $ 1,674,071 ​ $ 1,392,408 ​ Scheduled maturities of time deposits at December 31, 2020 for future years ending are as follows: ​ ​ ​ ​ ​ ​ At December 31, 2020 Maturing in 2021 ​ $ 340,867 Maturing in 2022 ​ ​ 88,529 Maturing in 2023 ​ ​ 19,991 Maturing in 2024 ​ ​ 20,131 Maturing in 2025 ​ ​ 33,027 Thereafter ​ ​ 1 Total ​ $ 502,546 ​ Interest expense by deposit category for the years ended December 31, 2020 and 2019 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2020 2019 Interest-bearing checking ​ $ 388 ​ $ 1,414 Savings and money market ​ 2,458 ​ 3,098 Certificates of deposit ​ 9,134 ​ 11,650 Total ​ $ 11,980 ​ $ 16,162 ​ The Company had related party deposits of approximately $4.0 million and $3.3 million at December 31, 2020 and 2019, respectively, which includes deposits held for directors and executive officers.

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	NOTE 9 - DEBT Borrowings The Bank is a member of the FHLB of Des Moines, which entitles it to certain benefits including a variety of borrowing options consisting of a secured credit line that allows both fixed and variable rate advances. The FHLB borrowings at December 31, 2020 and 2019, consisted of a warehouse securities credit line (“securities line”), which allows advances with interest rates fixed at the time of borrowing and a warehouse federal funds (“Fed Funds”) advance, which allows daily advances at variable interest rates. Credit capacity is primarily determined by the value of assets collateralized at the FHLB, funds on deposit at the FHLB, and stock owned by the Bank. Credit is limited to 45% of the Company’s total assets and available pledged assets. The Bank entered into an Advances, Pledges and Security Agreement with the FHLB for which specific loans are pledged to secure these credit lines. At December 31, 2020, loans of approximately $774.8 million were pledged to the FHLB. At December 31, 2020, the Bank’s total borrowing capacity was $568.2 million with the FHLB of Des Moines, with unused borrowing capacity of $459.9 million. In addition, all FHLB stock owned by the Company is collateral for credit lines. The Bank maintains a short-term borrowing line with the FRB with total credit based on eligible collateral. The Bank can borrow under the Term Auction or Term Facility at rates published by the San Francisco FRB. At December 31, 2020 and 2019, the Bank had approximately $369.2 million and $318.8 million, respectively, in pledged consumer loans with a Term Auction or Term Facility borrowing capacity of $179.6 million and $156.1 million, respectively, of which none was outstanding at either date. The Bank also had $101.0 million unsecured Fed Funds lines of credit with other financial institutions of which none was outstanding at December 31, 2020. The Company participated in the PPP and has 423 PPP loans totaling $62.1 million at December 31, 2020 for borrowers in the communities we serve. The Company utilized the FRB's PPPLF, pursuant to which it pledged its PPP loans as collateral at face value to obtain FRB non-recourse advances. As of December 31, 2020, the Company has borrowed $63.3 million under the PPPLF, with no additional borrowing capacity. Advances under the PPPLF incur interest at a per annum rate of 0.35%. The maturity date of any PPPLF advance (the “Maturity Date”) will be the maturity date of the PPP loan pledged to secure the PPPLF advance. The Maturity Date of any PPPLF advance will be accelerated on and to the extent of (i) the date of any loan forgiveness reimbursement by the SBA for any PPP loan securing the PPPLF advance; or (ii) the date of purchase by the SBA from the Bank of any PPP loan securing the PPPLF loan advance to realize on the SBA’s guarantee of the PPP loan. PPPLF loans may be prepaid in full or in part, without penalty. The Bank shall prepay PPPLF advances (i) on the date and to the extent of the payment by the SBA for the amount of covered loan forgiveness for any PPP loan securing the PPPLF advance; (ii) on the date of purchase by the SBA from the Bank of a PPP loan securing the PPPLF advances to realize on the SBA’s guarantee of such PPP loans; or (iii) on the date and to the extent a borrower under a PPP loan repays or prepays such PPP loans, in each case, so that the amount of any PPPLF advances outstanding does not exceed the outstanding amount of PPP loans pledged to secure such PPPLF advances. At December 31, 2020, of the $63.3 million of borrowings under PPPLF, $62.0 million were set to mature in 2022 and $1.3 million in 2025. Advances on these lines at December 31, 2020 and 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Federal Home Loan Bank ​ $ 102,528 ​ $ 84,864 Paycheck Protection Program Liquidity Facility ​ ​ 63,281 ​ ​ — Total ​ $ 165,809 ​ $ 84,864 ​ Subsequent to December 31, 2020, on February 10, 2021, FS Bancorp, Inc. completed the private placement of $50.0 million of its 3.75% fixed-to-floating rate subordinated notes due 2031 (the “Notes”) at an offering price equal to 100% of the aggregate principal amount of the Notes, resulting in net proceeds, after placement agent fees and offering expenses, of approximately $49.3 million. For regulatory capital purposes, the subordinated notes have been structured to qualify initially as Tier 2 capital for the Company. ​ Subordinated Note On October 15, 2015 (the “Closing Date”), FS Bancorp, Inc. issued an unsecured subordinated term note in the aggregate principal amount of $10.0 million due October 1, 2025 (the “Subordinated Note”) pursuant to a Subordinated Loan Agreement with Community Funding CLO, Ltd. The Subordinated Note bears interest at an annual interest rate of 6.50%, payable by the Company quarterly in arrears on January 1, April 1, July 1 and October 1 of each year, commencing on the first such date following the Closing Date and on the maturity date. The Subordinated Note’s maturity date was October 1, 2025, but the Company prepaid with regulatory approval on January 4, 2021, five years after the Closing Date. The Company contributed $9.0 million of the proceeds from the Subordinated Note as additional capital to the Bank in the fourth quarter of 2015 and used the balance to fund general working capital and operating expenses. The maximum and average balances and weighted average interest rates on debt during the years ended December 31, 2020 and 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Maximum balance: ​ ​ ​ Federal Home Loan Bank advances and Fed Funds ​ $ 159,114 ​ $ 186,401 ​ Federal Reserve Bank ​ $ 40,000 ​ $ 5,000 ​ Fed Funds lines of credit ​ $ 865 ​ $ 5,000 ​ Subordinated note ​ $ 10,000 ​ $ 10,000 ​ Paycheck Protection Program Liquidity Facility ​ $ 74,112 ​ $ — ​ Average balance: ​ ​ ​ Federal Home Loan Bank advances and Fed Funds ​ $ 99,773 ​ $ 93,653 ​ Federal Reserve Bank ​ $ 1,096 ​ $ 167 ​ Fed Funds lines of credit ​ $ 3 ​ $ 318 ​ Subordinated note ​ $ 10,000 ​ $ 10,000 ​ Paycheck Protection Program Liquidity Facility ​ $ 46,965 ​ $ — ​ Weighted average interest rates ​ ​ ​ Federal Home Loan Bank advances and Fed Funds ​ 1.80 % 2.61 % Fed Funds ​ 0.25 % 2.96 % Fed Funds lines of credit ​ 0.36 % 2.09 % Subordinated note ​ ​ 6.50 % ​ 6.50 % Paycheck Protection Program Liquidity Facility ​ 0.35 % — % ​ Scheduled maturities of Federal Home Loan Bank advances were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest Years Ending December 31, Balances Rates 2021 ​ $ 75,000 1.60 % 2022 ​ 13,633 2.03 % 2023 ​ 13,895 1.77 % Total ​ $ 102,528 ​ ​

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2020
Compensation and Retirement Disclosure [Abstract]
Employee Benefits	NOTE 10 - EMPLOYEE BENEFITS Employee Stock Ownership Plan On January 1, 2012, the Company established an ESOP for eligible employees of the Company and the Bank. Employees of the Company and the Bank are eligible to participate in the ESOP if they have been credited with at least 1,000 1,000 The ESOP borrowed $2.6 million from FS Bancorp, Inc. and used those funds to acquire 259,210 shares of FS Bancorp, Inc. common stock in the open market at an average price of $10.17 per share during the second half of 2012. It is anticipated that the Bank will make contributions to the ESOP in amounts necessary to amortize the ESOP loan payable to FS Bancorp, Inc. over a period of 10 years, bearing interest at 2.30%. Intercompany expenses associated with the ESOP are eliminated in consolidation. Shares purchased by the ESOP with the loan proceeds are held in a suspense account and allocated to ESOP participants on a pro rata basis as principal and interest payments are made by the ESOP to FS Bancorp, Inc. The loan is secured by shares purchased with the loan proceeds and will be repaid by the ESOP with funds from the Bank’s discretionary contributions to the ESOP and earnings on the ESOP assets. Payments of principal and interest are due annually on December 31, the Company’s fiscal year end. On December 31, 2020, the ESOP paid the ninth annual installment of principal in the amount of $282,000, plus accrued interest of $13,000 pursuant to the ESOP loan agreement. As shares are committed to be released from collateral, the Company reports compensation expense equal to the average daily market prices of the shares at December 31, 2020 for the prior 90 days. These shares become outstanding for earnings per share computations. The compensation expense is accrued monthly throughout the year. Dividends on allocated ESOP shares are recorded as a reduction of retained earnings; dividends on unallocated ESOP shares are recorded as a reduction of debt and accrued interest. Compensation expense related to the ESOP for the years ended December 31, 2020 and 2019, was $1.3 million, and $1.5 million, respectively. Shares held by the ESOP at December 31, 2020 and December 31, 2019, were as follows (shown as actual): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances ​ Balances ​ at December 31, 2020 at December 31, 2019 Allocated shares ​ ​ 213,744 ​ ​ 189,511 Committed to be released shares ​ — ​ — Unallocated shares ​ 25,921 ​ 51,842 Total ESOP shares ​ 239,665 ​ 241,353 ​ ​ ​ ​ ​ ​ ​ Fair value of unallocated shares (in thousands) ​ $ 1,307 ​ $ 3,006 ​ 401(k) Plan The Company has a salary deferral 401(k) Plan covering substantially all of its employees. Employees are eligible to participate in the 401(k) plan at the date of hire if they are 18 years of age. Eligible employees may contribute through payroll deductions and are 100% vested at all times in their deferral contributions account. The Company matches 100% for contributions of 1% to 3%, and 50% for contributions of 4% to 5%. There was a $1.5 million and $1.2 million matching contribution for the years ended December 31, 2020 and 2019, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
INCOME TAXES
Income Taxes	NOTE 11 - INCOME TAXES The components of income tax expense for the years ended December 31, 2020 and 2019, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Provision for income taxes ​ ​ Current ​ $ 12,976 ​ $ 4,425 Deferred ​ (2,390) ​ 988 Total provision for income taxes ​ $ 10,586 ​ $ 5,413 ​ A reconciliation of the effective income tax rate with the federal statutory tax rates at December 31, 2020 and 2019 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ 2019 ​ ​ Amount ​ Rate ​ Amount ​ Rate Income tax provision at statutory rate $ 10,469 21.0 % $ 5,907 21.0 % Tax exempt income ​ (292) (0.6) ​ (225) (0.8) ​ Nondeductible items resulting in increase in tax ​ ​ 57 ​ 0.1 ​ ​ 129 ​ 0.5 ​ Increase (decrease) in tax resulting from other items ​ 175 0.4 ​ (78) (0.3) ​ Equity compensation ​ ​ (46) ​ (0.1) ​ ​ (691) ​ (2.5) ​ Executive compensation ​ ​ 8 ​ — ​ ​ 112 ​ 0.4 ​ ESOP ​ 215 0.4 ​ 259 0.9 ​ Total ​ $ 10,586 21.2 % $ 5,413 19.2 % ​ Total deferred tax assets and liabilities at December 31, 2020 and 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ Deferred Tax Assets 2020 2019 Net operating loss carryforward ​ $ 527 ​ $ 864 Allowance for loan losses ​ ​ 5,775 ​ ​ 2,844 Purchase accounting adjustments ​ ​ — ​ ​ 466 Other real estate owned ​ ​ 126 ​ ​ 126 Nonaccrued loan interest ​ 6 ​ 13 Restricted stock awards ​ 97 ​ 68 Non-qualified stock options ​ 251 ​ 185 Interest rate swaps designated as cash flow hedge ​ 265 ​ — Lease liability ​ ​ 1,113 ​ ​ 1,121 Accrued compensation ​ ​ 430 ​ ​ — Other ​ 224 ​ 351 Total deferred tax assets ​ 8,814 ​ 6,038 Deferred Tax Liabilities ​ ​ Loan origination costs ​ (2,134) ​ (1,341) Servicing rights ​ (2,708) ​ (2,525) Stock dividend - FHLB stock ​ (55) ​ (59) Property, plant, and equipment ​ (1,097) ​ (1,362) Purchase accounting adjustments ​ ​ (830) ​ ​ (1,404) Securities available-for-sale ​ ​ (958) ​ ​ (216) Lease right-of-use assets ​ ​ (1,090) ​ ​ (1,078) Other ​ ​ — ​ ​ (24) Total deferred tax liabilities ​ (8,872) ​ (8,009) Net deferred tax liabilities ​ $ (58) ​ $ (1,971) ​ The Company files a U.S. Federal income tax return and Oregon and Idaho state returns, which are subject to examination by tax authorities for years 2017 and later. At December 31, 2020 and 2019, the Company had no uncertain tax positions. The Company recognizes interest and penalties in tax expense and at December 31, 2020 and 2019, the Company recognized no interest and penalties. In response to the COVID-19 pandemic, the CARES Act, among other things, permits net operating loss (“NOL”) carryforwards and carrybacks to offset 100% of taxable income for taxable years beginning before 2021. In addition, the CARES Act allows NOLs incurred in 2018, 2019, and 2020 to be carried back to each of the five preceding taxable years to generate a refund of previously paid income taxes, and it provides options for accelerating refunds associated with previously paid alternative minimum taxes. The Company benefited from the alternative minimum tax refund provisions of the CARES Act and submitted accelerated refund claims during the year ended December 31, 2020. At December 31, 2020, the Company had a remaining NOL of approximately $2.4 million, which begins to expire in 2035. ​ On December 27, 2020, the CAA 2021 was signed into law and extends several provisions of the CARES Act. As of December 31, 2020, the Company has determined that neither this act nor changes to income tax laws or regulations in other jurisdictions have a significant impact on its effective tax rate. ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 12 - COMMITMENTS AND CONTINGENCIES Commitments - The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. The following table provides a summary of the Company’s commitments at December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ COMMITMENTS TO EXTEND CREDIT December 31, December 31, REAL ESTATE LOANS ​ 2020 2019 Commercial ​ $ 1,293 ​ $ 247 Construction and development ​ 143,666 ​ 95,031 One-to-four-family (includes locks for saleable loans) ​ 147,712 ​ 39,697 Home equity ​ 52,457 ​ 47,880 Multi-family ​ 658 ​ 622 Total real estate loans ​ 345,786 ​ 183,477 CONSUMER LOANS ​ 23,365 ​ 22,176 COMMERCIAL BUSINESS LOANS ​ ​ Commercial and industrial ​ 106,171 ​ 72,731 Warehouse lending ​ 52,909 ​ 33,888 Total commercial business loans ​ 159,080 ​ 106,619 Total commitments to extend credit ​ $ 528,231 ​ $ 312,272 ​ Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Since many of the commitments are expected to expire without being drawn upon, the amount of the total commitments does not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation of the party. Collateral held varies, but may include accounts receivable, inventory, property and equipment, residential real estate, and income-producing commercial properties. Unfunded commitments under commercial lines of credit, revolving credit lines and overdraft protection agreements are commitments for possible future extensions of credit to existing customers. These lines of credit are uncollateralized and usually do not contain a specified maturity date and ultimately may not be drawn upon to the total extent to which the Company is committed. The Company has established reserves for estimated losses from unfunded commitments of $407,000 and $293,000 at December 31, 2020 and 2019, respectively. One-to-four-family commitments included in the table above are accounted for as fair value derivatives and do not carry an associated holdback. The Company’s derivative positions are presented with discussion in “Note 17 - Derivatives.” The Company also sells one-to-four-family loans to the FHLB of Des Moines that require a limited level of recourse if the loans default and exceed a certain loss exposure. Specific to that recourse, the FHLB of Des Moines established a first loss account (“FLA”) related to the loans and required a credit enhancement (“CE”) obligation by the Bank to be utilized after the FLA is used. Based on loans sold through December 31, 2020, the total loans sold to the FHLB were $30.0 million with the FLA being $938,000 and the CE obligation at $811,000 or 2.7% of the loans outstanding. Management has established a holdback of 10% of the outstanding CE obligation, or $272,000, which is a part of the off-balance sheet holdback for loans sold. At December 31, 2020, there were $498,000 of loans sold to the FHLB of Des Moines greater than 30 days past their contractual payment due date, compared to none at December 31, 2019. Contingent liabilities for loans held for sale these guarantees for one-to-four-family loans sold into the secondary market at December 31, 2020 and 2019, respectively, which is included in other liabilities in the Consolidated Balance Sheets. The Company has entered into a severance agreement with its Chief Executive Officer (“CEO”). The severance agreement, subject to certain requirements, generally includes a lump sum payment to the CEO equal to 24 months of base compensation in the event their employment is involuntarily terminated, other than for cause or the executive terminates his employment with good reason, as defined in the severance agreement. The Company has entered into change of control agreements with its Chief Financial Officer, Chief Operating Officer, Chief Lending Officer, Chief Credit Officer, Chief Risk Officer, Chief Human Resources Officer, Senior Vice President Compliance Officer, Executive Vice President of Retail Banking and Marketing, and the Executive Vice President of Home Lending. The change of control agreements, subject to certain requirements, generally remain in effect until canceled by either party upon at least 24 months prior written notice. Under the change of control agreements, the executive generally will be entitled to a change of control payment from the Company if the executive is involuntarily terminated within six months preceding or 12 months after a change in control (as defined in the change of control agreements). In such an event, the executives would each be entitled to receive a cash payment in an amount equal to 12 months of their then current salary, subject to certain requirements in the change of control agreements. As a result of the nature of our activities, the Company is subject to various pending and threatened legal actions, which arise in the ordinary course of business. From time to time, subordination liens may create litigation which requires us to defend our lien rights. In the opinion of management, liabilities arising from these claims, if any, will not have a material effect on our financial position. The Company had no material pending legal actions at December 31, 2020.

Significant Concentration of Cr

Significant Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Significant Concentration of Credit Risk	NOTE 13 - SIGNIFICANT CONCENTRATION OF CREDIT RISK Most of the Company’s commercial and multi-family real estate, construction, residential, and/or commercial business lending activities are with customers located in Western Washington and near the one loan production office located in the Tri-Cities, Washington. The Company originates real estate, consumer, and commercial business loans and has concentrations in these areas, however, indirect home improvement loans, including solar-related home improvement loans are originated through a network of home improvement contractors and dealers located throughout Washington, Oregon, California, Idaho, Colorado, Arizona, Minnesota, and Nevada. Loans are generally secured by collateral and rights to collateral vary and are legally documented to the extent practicable. Local economic conditions may affect borrowers’ ability to meet the stated repayment terms. The concentration on commercial real estate remains below the 300% of Risk Based Capital regulatory threshold and the subset of construction concentration, excluding owner-occupied loans is within Board approved limits. The construction, land development, and other land concentration represents less than 100% of the Bank’s total regulatory capital at 89.6% and is focused on in city, in fill vertical construction financing in King and Snohomish counties. Local economic conditions may affect borrowers’ ability to meet the stated repayment terms. ​

Regulatory Capital

Regulatory Capital	12 Months Ended
	Dec. 31, 2020
Regulatory Capital Requirements [Abstract]
Regulatory Capital	NOTE 14 - REGULATORY CAPITAL The Bank is subject to various regulatory capital requirements administered by the Federal Reserve and the FDIC. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy guidelines of the regulatory framework for prompt corrective action, the Bank must meet specific capital adequacy guidelines that involve quantitative measures of the Bank’s assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The Bank’s capital classification is also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. The federal banking agencies jointly issued a final rule that provides for an optional, simplified measure of capital adequacy, the community bank leverage ratio framework, for qualifying community banking organizations, consistent with Section 201 of the Economic Growth, Regulatory Relief, and Consumer Protection Act. This final rule is applicable to all non-advanced approaches FDIC-supervised institutions with less than $10 billion in total consolidated assets. The community bank leverage ratio (“CBLR”) final rule was effective on January 1, 2020, and allows qualifying community banking organizations to calculate a leverage ratio to measure capital adequacy. Banks opting into the CBLR framework are not required to calculate or report risk-based capital. A qualifying community banking organization is defined as having less than $10 billion in total consolidated assets, a leverage ratio greater than 9%, off-balance sheet exposures of 25% or less of total consolidated assets, and trading assets and liabilities of 5% or less of total consolidated assets. The final rule adopted Tier 1 capital and the existing leverage ratio into the community bank leverage ratio framework. A bank electing the framework is not subject to other capital and leverage requirements. A bank electing the framework that ceases to meet any qualifying criteria in a future period and that has a leverage ratio greater than 8% will be allowed a grace period of two reporting periods to satisfy the CBLR qualifying criteria or comply with the generally applicable capital requirements. A bank may opt out of the framework at any time, without restriction, by reverting to the generally applicable risk-based capital rule. In response to the COVID-19 pandemic, the CARES Act was signed into law on March 27, 2020. Among other things, the CARES Act directs federal banking agencies to adopt interim final rules to lower the threshold under the CBLR from 9% to 8% and to provide a reasonable grace period for a community bank that falls below the threshold to regain compliance, in each case until the earlier of the termination date of the national emergency or December 31, 2020. In April 2020, the federal banking agencies issued two interim final rules implementing this directive. One interim final rule provides that, as of the second quarter 2020, banking organizations with leverage ratios of 8% or greater (and that meet the other existing qualifying criteria) may elect to use the CBLR framework. It also establishes a two-quarter grace period for qualifying community banking organizations whose leverage ratios fall below the 8% CBLR requirement, so long as the banking organization maintains a leverage ratio of 7% or greater. The second interim final rule provides a transition from the temporary 8% CBLR requirement to a 9% CBLR requirement. It establishes a minimum CBLR of 8% for the second through fourth quarters of 2020, 8.5% for 2021, and 9% thereafter, and maintains a two-quarter grace period for qualifying community banking organizations whose leverage ratios fall no more than 100 basis points below the applicable CBLR requirement. Effective October 1, 2020, the final rule made no change to the interim final rule issued in April. ​ The ​ FS Bancorp, Inc. is a bank holding company registered with the Federal Reserve. Bank holding companies are subject to capital adequacy requirements of the Federal Reserve under the Bank Holding Company Act of 1956, as amended, and the regulations of the Federal Reserve. Bank holding companies with less than $3.0 billion in assets are generally not subject to compliance with the Federal Reserve’s capital regulations, which are generally the same as the capital regulations applicable to the Bank. The Federal Reserve has a policy that a bank holding company is required to serve as a source of financial and managerial strength to the holding company’s subsidiary bank and expects the holding company’s subsidiary bank to be well capitalized under the prompt corrective action regulations. If FS Bancorp, Inc. was subject to regulatory guidelines for bank holding companies with $3.0 billion or more in assets at December 31, 2020, FS Bancorp, Inc. would have exceeded all regulatory capital requirements. The Tier 1 leverage-based capital ratio calculated for FS Bancorp, Inc. at December 31, 2020 was 11.1%, compared to 11.3% at December 31, 2019. ​

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 15 - FAIR VALUE MEASUREMENTS The Company determines fair value based on the requirements established in Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements, Financial Instruments - Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities, The following definitions describe the levels of inputs that may be used to measure fair value: Level 1 Level 2 Level 3 The following methods were used to estimate the fair value of certain assets and liabilities on a recurring and nonrecurring basis. Securities Mortgage Loans Held for Sale - Derivative Instruments - Impaired Loans - Other Real Estate Owned Servicing Rights The following table presents securities available-for-sale, mortgage loans held for sale, and derivative assets and liabilities measured at fair value on a recurring basis at the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Financial Assets ​ At December 31, 2020 Securities available-for-sale: Level 1 Level 2 Level 3 Total U.S. agency securities ​ $ — ​ $ 8,105 ​ $ — ​ $ 8,105 Corporate securities ​ — ​ 10,016 ​ 984 ​ 11,000 Municipal bonds ​ — ​ 71,730 ​ 127 ​ 71,857 Mortgage-backed securities ​ — ​ 68,187 ​ — ​ 68,187 U.S. Small Business Administration securities ​ — ​ 18,869 ​ — ​ 18,869 Mortgage loans held for sale, at fair value ​ ​ — ​ ​ 166,448 ​ ​ — ​ ​ 166,448 Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ ​ — ​ ​ 21 ​ ​ — ​ ​ 21 Interest rate lock commitments with customers ​ ​ — ​ ​ — ​ ​ 4,024 ​ ​ 4,024 Total assets measured at fair value ​ $ — ​ $ 343,376 ​ $ 5,135 ​ $ 348,511 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mandatory and best effort forward commitments with investors ​ $ — ​ $ — ​ $ (67) ​ $ (67) Forward TBA mortgage-backed securities ​ ​ — ​ ​ (1,602) ​ ​ — ​ ​ (1,602) Interest rate swaps ​ ​ — ​ ​ (1,252) ​ ​ — ​ ​ (1,252) Total liabilities measured at fair value ​ $ — ​ $ (2,854) ​ $ (67) ​ $ (2,921) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Financial Assets ​ At December 31, 2019 Securities available-for-sale: Level 1 Level 2 Level 3 Total U.S. agency securities ​ $ — ​ $ 9,066 ​ $ — ​ $ 9,066 Corporate securities ​ — ​ 9,546 ​ 1,024 ​ 10,570 Municipal bonds ​ — ​ 20,982 ​ 138 ​ 21,120 Mortgage-backed securities ​ — ​ 62,850 ​ — ​ 62,850 U.S. Small Business Administration securities ​ — ​ 22,451 ​ — ​ 22,451 Mortgage loans held for sale, at fair value ​ ​ — ​ ​ 69,699 ​ ​ — ​ ​ 69,699 Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate lock commitments with customers ​ ​ — ​ ​ — ​ ​ 557 ​ ​ 557 Total assets measured at fair value ​ $ — ​ $ 194,594 ​ $ 1,719 ​ $ 196,313 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mandatory and best effort forward commitments with investors ​ $ — ​ $ — ​ $ (195) ​ $ (195) Forward TBA mortgage-backed securities ​ ​ — ​ ​ (8) ​ ​ — ​ ​ (8) Total liabilities measured at fair value ​ $ — ​ $ (8) ​ $ (195) ​ $ (203) ​ The following table presents impaired loans, OREO, and servicing rights measured at fair value on a nonrecurring basis for which a nonrecurring change in fair value has been recorded during the reporting periods indicated. The amounts disclosed below represent the fair values at the time the nonrecurring fair value measurements were evaluated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Level 1 Level 2 Level 3 Total Impaired loans ​ $ — $ — $ 7,761 $ 7,761 OREO ​ ​ — ​ ​ — ​ ​ 90 ​ ​ 90 Servicing rights ​ ​ — ​ — ​ 12,833 ​ 12,833 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Level 1 Level 2 Level 3 Total Impaired loans ​ $ — $ — $ 3,128 $ 3,128 OREO ​ ​ — ​ ​ — ​ ​ 168 ​ ​ 168 Servicing rights ​ ​ — ​ — ​ 13,255 ​ 13,255 ​ Quantitative Information about Level 3 Fair Value Measurements - ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Level 3 ​ Significant ​ Weighted Average Fair Value ​ Valuation ​ Unobservable ​ ​ ​ December 31, ​ ​ December 31, ​ Instruments Techniques Inputs Range 2020 ​ 2019 RECURRING ​ ​ ​ ​ Interest rate lock commitments with customers Quoted market prices Pull-through expectations 80% - 99% ​ 91.6 % ​ 94.5 % Individual forward sale commitments with investors Quoted market prices Pull-through expectations 80% - 99% ​ 91.6 % ​ 94.5 % Corporate securities ​ Discounted cash flows ​ Discount rate ​ 2.5% ​ 2.5 % ​ 2.1 % Municipal bonds ​ Discounted cash flows ​ Discount rate ​ 6.4% ​ 6.4 % ​ 3.4 % NONRECURRING ​ ​ ​ ​ ​ Impaired loans Fair value of underlying collateral Discount applied to the obtained appraisal 10.0% ​ 10.0 % ​ 10.0 % OREO ​ Fair value of collateral ​ Discount applied to the obtained appraisal ​ 10.0% ​ 10.0 % ​ 10.0 % Servicing rights ​ Industry sources ​ Pre-payment speeds ​ 0% - 50% ​ 32.6 % ​ 17.1 % ​ An increase in the pull-through rate utilized in the fair value measurement of the interest rate lock commitments with customers and forward sale commitments with investors will result in positive fair value adjustments (and an increase in the fair value measurement). Conversely, a decrease in the pull-through rate will result in a negative fair value adjustment (and a decrease in the fair value measurement). The following table provides a reconciliation of assets and liabilities measured at fair value using significant unobservable inputs (Level 3) on a recurring basis during the years ended December 31, 2020 and 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Purchases ​ ​ ​ Net change in Net change in ​ Beginning and Sales and Transfers Ending fair value for fair value for 2020 Balance Issuances Settlements In Balance gains/(losses) (1) gains/(losses) (2) Interest rate lock commitments with customers ​ $ 557 ​ $ 53,281 ​ $ (49,814) ​ $ — ​ $ 4,024 ​ $ 3,467 ​ $ — Individual forward sale commitments with investors ​ ​ (195) ​ ​ (4,857) ​ ​ 4,985 ​ ​ — ​ ​ (67) ​ ​ 128 ​ ​ — Securities available-for-sale, at fair value ​ ​ 1,162 ​ ​ — ​ ​ (51) ​ ​ — ​ ​ 1,111 ​ ​ — ​ ​ (40) 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate lock commitments with customers ​ $ 503 ​ $ 11,063 ​ $ (11,009) ​ $ — ​ $ 557 ​ $ 54 ​ $ — Individual forward sale commitments with investors ​ ​ (34) ​ ​ (1,444) ​ ​ 1,283 ​ ​ — ​ ​ (195) ​ ​ (161) ​ ​ — Securities available-for-sale, at fair value ​ ​ — ​ ​ — ​ ​ — ​ ​ 1,162 ​ ​ 1,162 ​ ​ — ​ ​ — _____________________________ (1) Relating to items held at end of period included in income. (2) Relating to items held at end of period included in other comprehensive income. Gains (losses) on interest rate lock commitments carried at fair value are recorded in other noninterest income. Gains (losses) on forward sale commitments with investors carried at fair value are recorded in noninterest income. The following table provides estimated fair values of the Company’s financial instruments at December 31, 2020 and 2019, whether or not recognized at fair value in the Consolidated Balance Sheets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ 2020 ​ 2019 ​ Financial Assets Carrying Fair Carrying Fair ​ Level 1 inputs: Amount Value Amount Value ​ Cash and cash equivalents ​ $ 91,576 ​ $ 91,576 ​ $ 45,778 ​ $ 45,778 ​ Certificates of deposit at other financial institutions ​ 12,278 ​ 12,278 ​ 20,902 ​ 20,902 ​ Level 2 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities available-for-sale, at fair value ​ 176,907 ​ 176,907 ​ 124,895 ​ 124,895 ​ Securities held-to-maturity ​ ​ 7,500 ​ ​ 7,556 ​ ​ — ​ ​ — ​ Loans held for sale, at fair value ​ 166,448 ​ 166,448 ​ 69,699 ​ 69,699 ​ FHLB stock, at cost ​ 7,439 ​ 7,439 ​ 8,045 ​ 8,045 ​ Interest rate swaps ​ ​ 21 ​ ​ 21 ​ ​ — ​ ​ — ​ Accrued interest receivable ​ 7,030 ​ 7,030 ​ 5,908 ​ 5,908 ​ Level 3 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities available-for-sale, at fair value ​ ​ 1,111 ​ ​ 1,111 ​ ​ 1,162 ​ ​ 1,162 ​ Loans receivable, gross ​ 1,574,227 ​ 1,580,360 ​ 1,351,893 ​ 1,377,408 ​ Servicing rights, held at lower of cost or fair value ​ 12,595 ​ 12,833 ​ 11,560 ​ 13,255 ​ Fair value interest rate locks with customers ​ 4,024 ​ 4,024 ​ 557 ​ 557 ​ Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Level 2 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deposits ​ 1,674,071 ​ 1,674,328 ​ 1,392,408 ​ 1,385,658 ​ Borrowings ​ 165,809 ​ 167,680 ​ 84,864 ​ 85,268 ​ Subordinated note ​ 10,000 ​ 11,083 ​ 9,885 ​ 10,599 ​ Accrued interest payable ​ 406 ​ 406 ​ 273 ​ 273 ​ Interest rate swaps ​ ​ 1,252 ​ ​ 1,252 ​ ​ — ​ ​ — ​ Forward TBA mortgage-backed securities ​ 1,602 ​ 1,602 ​ 8 ​ 8 ​ Level 3 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mandatory and best effort forward commitments with investors ​ ​ 67 ​ ​ 67 ​ ​ 195 ​ ​ 195 ​ ​

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 16 - EARNINGS PER SHARE The Company computes earnings per share using the two-class method, which is an earnings allocation method for computing earnings per share that treats a participating security as having rights to earnings that would otherwise have been available to common shareholders. Basic earnings per share are computed by dividing income available to common shareholders by the weighted average number of common shares outstanding for the period. Unvested share-based awards containing non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and are included in the computation of earnings per share pursuant to the two-class method. Diluted earnings per share reflect the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity. For earnings per share calculations, the ESOP shares committed to be released are included as outstanding shares for both basic and diluted earnings per share. The following table presents a reconciliation of the components used to compute basic and diluted earnings per share for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, Numerator (in thousands): 2020 2019 Net income ​ $ 39,264 ​ $ 22,717 Dividends and undistributed earnings allocated to participating securities ​ ​ (192) ​ ​ (73) Net income available to common shareholders ​ $ 39,072 ​ $ 22,644 Denominator (shown as actual): ​ ​ ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 4,273,350 ​ 4,414,032 Dilutive shares ​ 81,019 ​ 108,992 Diluted weighted average common shares outstanding ​ 4,354,369 ​ 4,523,024 Basic earnings per share ​ $ 9.14 ​ $ 5.13 Diluted earnings per share ​ $ 8.97 ​ $ 5.01 Potentially dilutive weighted average share options that were not included in the computation of diluted earnings per share because to do so would be anti-dilutive ​ ​ 66,619 ​ ​ 36,337 ​

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	NOTE 17 - DERIVATIVES The Company regularly enters into commitments to originate and sell loans held for sale. The Company has established a hedging strategy to protect itself against the risk of loss associated with interest rate movements on loan commitments. The Company enters into contracts to sell forward TBA mortgage-backed securities. These commitments and contracts are considered derivatives but have not been designated as hedging instruments for reporting purposes under U.S. GAAP. Rather, they are accounted for as free-standing derivatives, or economic hedges, with changes in the fair value of the derivatives reported in noninterest income or noninterest expense. The Company recognizes all derivative instruments as either other assets or other liabilities on the Consolidated Balance Sheets and measures those instruments at fair value. Derivative instruments not related to mortgage banking activities primarily relate to interest rate swap agreements. The Company's objectives in using certain interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish this objective, the Company uses interest rate swaps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. ​ The Company has entered into interest rate swaps to reduce the exposure to variability in interest-related cash outflows attributable to changes in forecasted LIBOR-based borrowings and brokered deposits. These derivative instruments are designated as cash flow hedges. The hedged item is the LIBOR portion of the series of future adjustable rate borrowings and deposits over the term of the interest rate swap. Accordingly, changes to the amount of interest payment cash flows for the hedged transactions attributable to a change in credit risk are excluded from management’s assessment of hedge effectiveness. The Company tests for hedging effectiveness on a quarterly basis. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The Company has not recorded any hedge ineffectiveness since inception. The Company has master netting agreements with derivative dealers with which it does business, but reflects gross assets and liabilities as other assets and other liabilities, respectively, on the Consolidated Balance Sheets. ​ The net unrealized loss on cash flow hedges recorded in accumulated other comprehensive income was $967,000 , net of tax, at December 31, 2020. The Company reclassified realized losses of $198,000 from accumulated other comprehensive income to interest expense related to these cash flow hedges for the year ended December 31, 2020. The Company had no cash flow hedges in 2019. The Company expects that approximately $492,000 will be reclassified from accumulated other comprehensive income as an increase to interest expense over the next twelve months related to these cash flow hedges. The following tables summarize the Company’s derivative instruments at the dates indicated: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Fair Value Cash flow hedges: Notional Asset Liability Interest rate swaps ​ $ 90,000 ​ $ 21 ​ $ 1,252 Non-hedging derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ Fallout adjusted interest rate lock commitments with customers ​ ​ 136,739 ​ ​ 4,024 ​ ​ — Mandatory and best effort forward commitments with investors ​ 25,027 ​ — ​ 67 Forward TBA mortgage-backed securities ​ 232,000 ​ — ​ 1,602 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ Fair Value Non-hedging derivatives: Notional Asset Liability Fallout adjusted interest rate lock commitments with customers ​ $ 33,914 ​ $ 557 ​ $ — Mandatory and best effort forward commitments with investors ​ 43,752 ​ — ​ 195 Forward TBA mortgage-backed securities ​ 46,000 ​ — ​ 8 ​ At December 31, 2020 and 2019, the Company had $232.0 million and $46.0 million of TBA trades with counterparties that required margin collateral of $3.3 million and $1.2 million, respectively. At December 31, 2020, the Bank had pledged two securities with a carrying value of $3.4 million to secure interest rate swaps designated as cash flow hedges. Changes in the fair value of the non-hedging derivatives recognized in noninterest income on the Consolidated Statements of Income and included in gain on sale of loans resulted in a net gain of $6.3 million and $303,000 for the years ended December 31, 2020 and 2019, respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	NOTE 18 - ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The following were changes in accumulated other comprehensive income (loss) by component, net of tax, for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized Gains ​ ​ ​ ​ Gains and ​ and Losses ​ ​ ​ Losses on ​ on Available ​ ​ ​ ​ Cash Flow ​ for Sale ​ ​ Year Ended December 31, 2020 Hedges ​ Securities ​ Total Beginning balance ​ $ — ​ $ 788 ​ $ 788 Other comprehensive (loss) income before ​ ​ ​ ​ ​ ​ ​ ​ reclassification, net of tax ​ ​ (1,122) ​ ​ 2,947 ​ ​ 1,825 Amounts reclassified from accumulated other ​ ​ ​ ​ ​ ​ ​ ​ comprehensive income (loss), net of tax ​ ​ 155 ​ ​ (235) ​ ​ (80) Net current period other comprehensive (loss) income ​ (967) ​ ​ 2,712 ​ ​ 1,745 Ending balance ​ $ (967) ​ $ 3,500 ​ $ 2,533 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized Gains ​ ​ ​ ​ ​ Gains and ​ and Losses ​ ​ ​ ​ Losses on ​ on Available ​ ​ ​ ​ ​ Cash Flow ​ for Sale ​ ​ ​ Year Ended December 31, 2019 Hedges ​ Securities ​ Total Beginning balance ​ $ — ​ $ (1,479) ​ $ (1,479) Other comprehensive income before ​ ​ ​ ​ ​ ​ ​ ​ reclassification, net of tax ​ ​ — ​ ​ 2,292 ​ ​ 2,292 Amounts reclassified from accumulated other ​ ​ ​ ​ ​ ​ ​ ​ comprehensive loss, net of tax ​ ​ — ​ ​ (25) ​ ​ (25) Net current period other comprehensive income ​ — ​ ​ 2,267 ​ ​ 2,267 Ending balance ​ $ — ​ $ 788 ​ $ 788 ​

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock Options and Restricted Stock On May 17, 2018, the shareholders of FS Bancorp, Inc. approved the 2018 Equity Incentive Plan (the “2018 Plan”) that authorizes 650,000 shares of the Company’s common stock to be awarded. The 2018 Plan provides for the grant of incentive stock options, non-qualified stock options, and up to 163,000 restricted stock awards (“RSAs”) to directors, emeritus directors, officers, employees or advisory directors of the Company. On August 15, 2020, the Company awarded grants of 24,880 RSAs and 62,285 stock options with an exercise price equal to the market price of FS Bancorp’s common stock on the grant date of $42.70 per share. At December 31, 2020, there were 274,060 stock option awards and 92,905 RSAs available to be granted under the 2018 Plan. In September 2013, the shareholders of FS Bancorp, Inc. approved the FS Bancorp, Inc. 2013 Equity Incentive Plan (the “2013 Plan”). The Plan provides for the grant of stock options and RSAs. The 2013 Plan authorizes the grant of stock options totaling 324,013 shares of common stock to Company directors and employees of which 322,000 stock options were granted with an exercise price equal to the market price of FS Bancorp’s common stock at the grant date of May 8, 2014, of $16.89 per share. The 2013 Plan authorized the grant of RSAs totaling 129,605 shares to Company directors, advisory directors, emeritus directors, officers, and employees, all of which have been granted. All options and RSAs previously granted have vested at December 31, 2020. At December 31, 2020, there were 6,013 stock option awards available to be granted under the 2013 Plan. Total share-based compensation expense was $1.0 million for the year ended December 31, 2020, and $869,000 for the year ended December 31, 2019. The related income tax benefit was $214,000 and $182,000 for the years ended December 31, 2020 and 2019, respectively. Stock Options Both plans consist of stock option awards that may be granted as incentive stock options or non-qualified stock options. Stock option awards generally vest at one year for independent directors or over a five year period for employees and officers with 20% vesting on the anniversary date of each grant date as long as the award recipient remains in service to the Company. The options are exercisable after vesting for up to the remaining term of the original grant. The maximum term of the options granted is 10 years. Any unexercised stock options will expire 10 years after the grant date or sooner in the event of the award recipient’s termination of service with the Company or the Bank. The fair value of each stock option award is estimated on the grant date using a Black-Scholes Option pricing model that uses the following assumptions. The dividend yield is based on the current quarterly dividend in effect at the time of the grant. Historical employment data is used to estimate the forfeiture rate. The Company elected to use Staff Accounting Bulletin 107, simplified expected term calculation for the “Share-Based Payments” method permitted by the SEC to calculate the expected term. This method uses the vesting term of an option along with the contractual term, setting the expected life at 5.5 years for one-year vesting and 6.5 years for five-year vesting. The fair value of options granted was determined using the following weighted-average assumptions as of the grant date for the years ended December 31, 2020 and 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ Year Ended December 31, ​ 2020 2019 Dividend yield ​ ​ 1.97% ​ ​ 1.23% Expected volatility, maximum ​ 26.79% ​ 18.90% Risk-free interest rate, maximum ​ 0.42% ​ 1.45% Expected term in years, maximum ​ 6.5 ​ 6.5 Weighted-average grant date fair value per option granted ​ $ 8.00 ​ $ 8.80 ​ The following table presents a summary of the Company’s stock option plan awards during the year ended December 31, 2020 (shown as actual): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ ​ ​ Weighted- ​ Remaining ​ ​ ​ ​ ​ ​ ​ Average ​ Contractual Term In ​ Aggregate ​ ​ Shares ​ Exercise Price ​ Years ​ Intrinsic Value Outstanding at January 1, 2020 287,990 ​ $ 36.98 6.77 ​ $ 7,722,369 Granted 62,285 ​ $ 42.70 6.45 ​ ​ — Less exercised 14,398 ​ $ 16.89 — ​ $ 453,674 Forfeited or expired — ​ — — ​ — Outstanding at December 31, 2020 335,877 ​ $ 38.90 6.58 ​ $ 5,721,159 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Expected to vest, assuming a 0.31% annual forfeiture rate (1) 334,824 ​ $ 38.87 6.58 ​ $ 5,713,654 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercisable at December 31, 2020 174,988 ​ $ 28.62 4.69 ​ $ 4,733,571 _________________________ (1) Forfeiture rate has been calculated and estimated to assume a forfeiture of 3.1% of the options forfeited over 10 years. ​ At December 31, 2020, there was $1.5 million of total unrecognized compensation cost related to nonvested stock options granted under the 2018 plan. The cost is expected to be recognized over the remaining weighted-average vesting period of 3.4 years. Restricted Stock Awards The RSAs’ fair value is equal to the value of the stock-based on the market price of FS Bancorp’s common stock on the grant date and compensation expense is recognized over the vesting period of the awards based on the fair value of the restricted stock. Shares for the 2018 Plan generally vest at one year for independent directors or over a five-year period for employees and officers beginning on the grant date. Any unvested RSAs will expire after vesting or sooner in the event of the award recipient’s termination of service with the Company or the Bank. The following table presents a summary of the Company’s nonvested awards during the year ended December 31, 2020 (shown as actual): ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ Grant-Date Fair Value Nonvested Shares ​ Shares ​ Per Share Nonvested at January 1, 2020 40,215 ​ $ 53.64 Granted 24,880 ​ $ 42.70 Less vested 10,003 ​ $ 53.67 Forfeited or expired — ​ — Nonvested at December 31, 2020 55,092 ​ $ 48.70 ​ At December 31, 2020, there was $­­­­­2.4 million of total unrecognized compensation costs related to nonvested shares granted under the 2018 plan as RSAs. The cost is expected to be recognized over the remaining weighted-average vesting period of 3.6 years.

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Business Segments	NOTE 20 - BUSINESS SEGMENTS The Company’s business segments are determined based on the products and services provided, as well as the nature of the related business activities, and they reflect the manner in which financial information is currently evaluated by management. This process is dynamic and is based on management’s current view of the Company’s operations and is not necessarily comparable with similar information for other financial institutions. The Company defines its business segments by product type and customer segment which it has organized into two lines of business: commercial and consumer banking and home lending. The Company uses various management accounting methodologies to assign certain income statement items to the responsible operating segment, including: ● a funds transfer pricing (“FTP”) system, which allocates interest income credits and funding charges between the segments, assigning to each segment a funding credit for its liabilities, such as deposits, and a charge to fund its assets; ● a cost per loan serviced allocation based on the number of loans being serviced on the balance sheet and the number of loans serviced for third parties; ● an allocation based upon the approximate square footage utilized by the home lending segment in Company owned locations; ● an allocation of charges for services rendered to the segments by centralized functions, such as corporate overhead, which are generally based on the number of full-time employees (“FTEs”) in each segment; and ● an allocation of the Company’s consolidated income taxes which are based on the effective tax rate applied to the segment’s pretax income or loss. The FTP methodology is based on management’s estimated cost of originating funds including the cost of overhead for deposit generation. A description of the Company’s business segments and the products and services that they provide is as follows: Commercial and Consumer Banking Segment The commercial and consumer banking segment provides diversified financial products and services to our commercial and consumer customers through Bank branches, automated teller machines (“ATM”), online banking platforms, mobile banking apps, and telephone banking. These products and services include deposit products; residential, consumer, business and commercial real estate lending portfolios and cash management services. The Company originates consumer loans, commercial and multi-family real estate loans, construction loans for residential and multi-family construction, and commercial business loans. At December 31, 2020, the Company’s retail deposit branch network consisted of 21 branches in the Pacific Northwest. This segment is also responsible for the management of the investment portfolio and other assets of the Bank. Home Lending Segment The home lending segment originates one-to-four-family residential mortgage loans primarily for sale in the secondary markets as well as originating adjustable rate mortgage (“ARM”) loans held for investment. The majority of mortgage loans are sold to or securitized by FNMA, FHLMC, GNMA or the FHLB of Des Moines, while the Company retains the right to service these loans. Loans originated under the guidelines of the Federal Housing Administration or FHA, US Department of Veterans Affairs or VA, and United States Department of Agriculture or USDA are generally sold servicing released to a correspondent bank or mortgage company. The Company has the option to sell loans on a servicing-released or servicing-retained basis to securitizers and correspondent lenders. A small percentage of loans are brokered to other lenders. On occasion, the Company may sell a portion of its MSR portfolio and may sell small pools of loans initially originated to be held in the loan portfolio. The Company manages the loan funding and the interest rate risk associated with the secondary market loan sales and the retained one-to-four-family mortgage servicing rights within this business segment. One-to-four-family loans originated for investment are allocated to the home lending segment with a corresponding provision expense and FTP for cost of funds. Segment Financial Results The tables below summarize the financial results for each segment based on the factors mentioned above within each segment for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2020 Condensed income statement: Home Lending Commercial and Consumer Banking Total Net interest income (1) $ 5,123 ​ $ 68,997 $ 74,120 Provision for loan losses ​ (2,758) ​ (10,278) ​ (13,036) Noninterest income ​ 44,808 ​ 10,551 ​ 55,359 Noninterest expense ​ (17,351) ​ (49,242) ​ (66,593) Income before provision for income taxes ​ 29,822 ​ 20,028 ​ 49,850 Provision for income taxes ​ (6,333) ​ (4,253) ​ (10,586) Net income $ 23,489 ​ $ 15,775 $ 39,264 Total assets ​ $ 460,409 ​ $ 1,652,832 ​ $ 2,113,241 Total average assets for year ended $ 396,367 ​ $ 1,543,681 $ 1,940,048 FTEs ​ 152 ​ 354 ​ 506 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2019 Condensed income statement: Home Lending Commercial and Consumer Banking Total Net interest income (1) $ 6,307 ​ $ 64,001 $ 70,308 Provision for loan losses ​ (433) ​ (2,447) ​ (2,880) Noninterest income ​ 13,209 ​ 9,826 ​ 23,035 Noninterest expense ​ (14,283) ​ (48,050) ​ (62,333) Income before provision for income taxes ​ 4,800 ​ 23,330 ​ 28,130 Provision for income taxes ​ (924) ​ (4,489) ​ (5,413) Net income $ 3,876 ​ $ 18,841 $ 22,717 Total assets ​ $ 312,404 ​ $ 1,400,652 ​ $ 1,713,056 Total average assets for year ended $ 272,901 ​ $ 1,377,468 $ 1,650,369 FTEs ​ 127 ​ 325 ​ 452 ___________________________ (1) Net interest income is the difference between interest earned on assets and the cost of liabilities to fund those assets. Interest earned includes actual interest earned on segment assets and, if the segment has excess liabilities, interest credits for providing funding to the other segment. The cost of liabilities includes interest expense on segment liabilities and, if the segment does not have enough liabilities to fund its assets, a funding charge based on the cost of assigned liabilities to fund segment assets.

Revenue From Contracts With Cus

Revenue From Contracts With Customers	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customers	NOTE 21 - REVENUE FROM CONTRACTS WITH CUSTOMERS Revenue Recognition In accordance with Topic 606, revenues are recognized when control of promised goods or services is transferred to customers in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services that are promised within each contract and identifies those that contain performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. All of the Company’s revenue from contracts with customers in-scope of ASC 606 is recognized in noninterest income and included in our commercial and consumer banking segment. The following table presents noninterest income, segregated by revenue streams in-scope and out-of-scope of Topic 606, for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands): ​ At or For the Year Ended December 31, Noninterest income 2020 2019 In-scope of Topic 606: ​ ​ ​ ​ ​ ​ Debit card interchange fees ​ $ 1,879 ​ $ 1,848 Deposit service and account maintenance fees ​ ​ 786 ​ ​ 1,065 Noninterest income (in-scope of Topic 606) ​ ​ 2,665 ​ ​ 2,913 Noninterest income (out-of-scope of Topic 606) ​ ​ 52,694 ​ ​ 20,122 Total noninterest income ​ $ 55,359 ​ $ 23,035 ​ Deposit Fees The Bank earns fees from its deposit customers for account maintenance, transaction-based services and overdraft charges. Account maintenance fees consist primarily of account fees and analyzed account fees charged on deposit accounts on a monthly basis. The performance obligation is satisfied and the fees are recognized on a monthly basis as the service period is completed. Transaction-based fees on deposits accounts are charged to deposit customers for specific services provided to the customer, such as wire fees, as well as charges against the account, such as fees for non-sufficient funds and overdrafts. The performance obligation is completed as the transaction occurs and the fees are recognized at the time each specific service is provided to the customer. Debit Interchange Income Debit and ATM interchange income represent fees earned when a debit card issued by the Bank is used. The Bank earns interchange fees from debit cardholder transactions through the Visa payment network. Interchange fees from cardholder transactions represent a percentage of the underlying transaction value and are recognized daily, concurrently with the transaction processing services provided to the cardholder. The performance obligation is satisfied and the fees are earned when the cost of the transaction is charged to the cardholders’ debit card.

Goodwill and other Intangible A

Goodwill and other Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	NOTE 22 - GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill and certain other intangibles generally arise from business combinations accounted for under the acquisition method of accounting. Goodwill totaled $2.3 million at December 31, 2020 and 2019, and represents the excess of the total acquisition price paid over the fair value of the assets acquired, net of the fair values of liabilities assumed as a result of the Branch Purchase in 2016. Goodwill is not amortized but is evaluated for impairment on an annual basis at December 31 of each year or whenever events or changes in circumstances indicate the carrying value may not be recoverable. The Company performed an impairment analysis at December 31, 2020 and determined that no impairment of goodwill existed. However, if adverse economic conditions or the decrease in the Company’s stock price and market capitalization as a result of the COVID-19 pandemic were to be deemed sustained rather than temporary, it may significantly affect the fair value of our goodwill. Accordingly, no assurances can be given that the Company will not record an impairment loss on goodwill in the future. Core deposit intangible (“CDI”) is evaluated for impairment whenever events or changes in circumstances indicate that its carrying amount may not be recoverable, with any changes in estimated useful life accounted for prospectively over the revised remaining life. As of December 31, 2020, management believes that there have been no events or changes in the circumstances that would indicate a potential impairment of CDI. The following table summarizes the changes in the Company’s other intangible assets comprised solely of CDI for the years ended December 31, 2020, and December 31, 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other Intangible Assets ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ Gross CDI Amortization Net CDI Balance, December 31, 2018 ​ $ 7,490 ​ $ (1,273) ​ $ 6,217 Amortization ​ ​ — ​ ​ (760) ​ ​ (760) Balance, December 31, 2019 ​ ​ 7,490 ​ ​ (2,033) ​ ​ 5,457 Amortization ​ ​ — ​ ​ (706) ​ ​ (706) Balance, December 31, 2020 ​ $ 7,490 ​ $ (2,739) ​ $ 4,751 ​ The CDI represents the fair value of the intangible core deposit base acquired in business combinations. The CDI will be amortized on a straight-line basis over 10 years for the CDI related to the Anchor Acquisition and on an accelerated basis over approximately nine years for the CDI related to the Branch Purchase. Total amortization expense was $706,000 for the year ended December 31, 2020, and $760,000 for the year ended December 31, 2019. Amortization expense for CDI is expected to be as follows for the years ended December 31: ​ ​ ​ ​ ​ 2021 $ 691 2022 ​ 691 2023 ​ 691 2024 ​ 621 2025 ​ ​ 525 Thereafter ​ 1,532 Total ​ $ 4,751 ​

Parent Company Only Financial I

Parent Company Only Financial Information	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Parent Company Only Financial Information	NOTE 23 - PARENT COMPANY ONLY FINANCIAL INFORMATION The Condensed Balance Sheets, Statements of Income, and Statements of Cash Flows for FS Bancorp, Inc. (Parent Only) are presented below: ​ ​ ​ ​ ​ ​ ​ ​ Condensed Balance Sheets ​ December 31, Assets ​ 2020 ​ 2019 Cash and due from banks ​ $ 14,531 ​ $ 5,568 Investment in subsidiary ​ 225,484 ​ 204,570 Other assets ​ 202 ​ 172 Total assets ​ $ 240,217 ​ $ 210,310 Liabilities and Stockholders' Equity ​ ​ ​ Subordinated note, net ​ 10,000 ​ 9,885 Other liabilities ​ ​ 210 ​ 183 Total liabilities ​ 10,210 ​ 10,068 Stockholders' equity ​ 230,007 ​ 200,242 Total liabilities and stockholders' equity ​ $ 240,217 ​ $ 210,310 ​ ​ ​ ​ ​ ​ ​ ​ Condensed Statements of Income ​ Year Ended December 31, ​ 2020 2019 Interest from subsidiary ​ $ — ​ $ 2 Interest expense on subordinated note ​ ​ (776) ​ ​ (679) Dividends received from subsidiary ​ ​ 20,862 ​ ​ 3,935 Other expenses ​ (195) ​ (142) Income before income tax benefit and equity in undistributed net income of subsidiary ​ 19,891 ​ 3,116 Income tax benefit ​ 204 ​ 172 Equity in undistributed earnings of subsidiary ​ ​ 19,169 ​ ​ 19,429 Net income ​ $ 39,264 ​ $ 22,717 ​ ​ ​ ​ ​ ​ ​ ​ Condensed Statements of Cash Flows Year Ended December 31, ​ 2020 2019 Cash flows from operating activities: ​ ​ ​ ​ ​ ​ Net income ​ $ 39,264 ​ $ 22,717 Equity in undistributed net income of subsidiary ​ (19,169) ​ (19,429) Amortization ​ 115 ​ 20 ESOP compensation expense for allocated shares ​ 1,025 ​ 1,231 Share-based compensation expense related to stock options and restricted stock ​ 1,020 ​ 869 Other assets ​ (30) ​ 3 Other liabilities ​ 27 ​ 11 Net cash from operating activities ​ 22,252 ​ 5,422 Cash flows from investing activities: ​ ​ ​ Net proceeds from ESOP ​ 282 ​ 275 Net cash from investing activities ​ 282 ​ 275 Cash flows used by financing activities: ​ ​ ​ (Disbursements) proceeds from stock options exercised ​ (161) ​ 705 Common stock repurchased for employee/director taxes paid on restricted stock awards ​ ​ (34) ​ ​ (204) Common stock repurchased ​ (9,802) ​ (4,800) Dividends paid on common stock ​ ​ (3,574) ​ ​ (2,856) Net cash used by financing activities ​ (13,571) ​ (7,155) Net increase (decrease) in cash and cash equivalents ​ 8,963 ​ (1,458) Cash and cash equivalents, beginning of year ​ 5,568 ​ 7,026 Cash and cash equivalents, end of year ​ $ 14,531 ​ $ 5,568 ​

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Basis of Presentation and Summary of Significant Accounting Policies
Financial Statement Presentation	Financial Statement Presentation - Amounts presented in the consolidated financial statements and footnote tables are rounded and presented to the nearest thousands of dollars except per share amounts. If the amounts are above $1.0 million, they are rounded one decimal point, and if they are above $1.0 billion, they are rounded two decimal points.
Principles of Consolidation	Principles of Consolidation -
Segment Reporting	Segment Reporting -
Subsequent Events	Subsequent Events -
Cash and Cash Equivalents	Cash and Cash Equivalents -
Securities	Securities - non-contingently callable debt securities which are amortized to the earliest call date, rather than the contractual maturity date. ​ Unrealized holding gains and losses, net of the related deferred tax effect, are reported as a net amount in a separate component of equity entitled accumulated other comprehensive income (loss). Any declines in the values of these securities that are considered to be other-than-temporary-impairment (“OTTI”) and credit-related are recognized in earnings. Noncredit-related OTTI on securities not expected to be sold is recognized in other comprehensive income (loss). The review for OTTI is conducted on an ongoing basis and takes into account the severity and duration of the impairment, recent events specific to the issuer or industry, fair value in relationship to cost, extent and nature of change in fair value, creditworthiness of the issuer including external credit ratings and recent downgrades, trends and volatility of earnings, current analysts’ evaluations, and other key measures. In addition, the Company does not intend to sell the securities and it is more likely than not that we will not be required to sell the securities before recovery of their amortized cost basis. In doing this, we take into account our balance sheet management strategy and consideration of current and future market conditions. Dividends and interest income are recognized when earned.
Federal Home Loan Bank Stock	Federal Home Loan Bank Stock - Management evaluates FHLB stock for impairment as needed. Management’s determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. The determination of whether a decline affects the ultimate recoverability of cost is influenced by criteria such as (1) the significance of any decline in net assets of the FHLB as compared with the capital stock amount for the FHLB and the length of time this situation has persisted; (2) commitments by the FHLB to make payments required by law or regulation and the level of such payments in relation to the operating performance of the FHLB; (3) the impact of legislative and regulatory changes on institutions and, accordingly, the customer base of the FHLB; and (4) the liquidity position of the FHLB. Based on its evaluation, management determined that there was no impairment of FHLB stock at December 31, 2020 and 2019, respectively.
Loans Held for Sale	Loans Held for Sale -
Other Real Estate Owned	Other Real Estate Owned -
Derivatives	Derivatives - The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and resulting designation. The Company’s hedging policies permit the use of various derivative financial instruments to manage interest rate risk or to hedge specified assets and liabilities. To qualify for hedge accounting, derivatives must be highly effective at reducing the risk associated with the exposure being hedged and must be designated as a hedge at the inception of the derivative contract. If derivative instruments are designated as fair value hedges, and such hedges are highly effective, both the change in the fair value of the hedge and the hedged item are included in current earnings. If derivative instruments are designated as cash flow hedges, fair value adjustments related to the effective portion are recorded in other comprehensive income and are reclassified to earnings when the hedged transaction is reflected in earnings. Ineffective portions of cash flow hedges are reflected in earnings as they occur. Actual cash receipts and/or payments and related accruals on derivatives related to hedges are recorded as adjustments to the interest income or interest expense associated with the hedged item. During the life of the hedge, the Company formally assesses whether derivatives designated as hedging instruments continue to be highly effective in offsetting changes in the fair value or cash flows of hedged items. If it is determined that a hedge has ceased to be highly effective, the Company will discontinue hedge accounting prospectively. At such time, previous adjustments to the carrying value of the hedged item are reversed into current earnings and the derivative instrument is reclassified to a trading position recorded at fair value. For derivatives not designated as hedges, changes in fair value are recognized in earnings, in noninterest income.
Loans Receivable	Loans Receivable - Interest on loans is accrued daily based on the principal amount outstanding. Generally, the accrual of interest on loans is discontinued when, in management’s opinion, the borrower may be unable to meet payments as they become due or when they are past due 90 days as to either principal or interest (based on contractual terms), unless they are well secured and in the process of collection. All interest accrued but not collected for loans that are placed on nonaccrual status or charged off are reversed against interest income. Subsequent collections on a cash basis are applied proportionately to past due principal and interest, unless collectability of principal is in doubt, in which case all payments are applied to principal. Loans are returned to accrual status when the loan is performing according to its contractual terms for at least six months and the collectability of principal and interest is no longer doubtful. The Company did not designate loans with payment deferrals granted due to the novel coronavirus of 2019 (“COVID-19’) pandemic as delinquent in accordance with provisions of The Coronavirus Aid, Relief, and Economic Security Act of 2020 (the “CARES Act”) and the Consolidated Appropriations Act, 2021 (the “CAA 2021”) and related regulatory guidance.
Impaired Loans	Impaired Loans - The categories of nonaccrual loans and impaired loans overlap, although they are not coextensive. The Company considers all circumstances regarding the loan and borrower on an individual basis when determining whether an impaired loan should be placed on nonaccrual status, such as the financial strength of the borrower, the collateral value, reasons for delay, payment record, the amount of past due and the number of days past due. Loans that experience insignificant payment delays and payment shortfalls are generally not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of shortfall in relation to the principal and interest owed.
Troubled Debt Restructured Loans	Troubled Debt Restructured Loans the maturity at an interest rate below current market; a reduction in the face amount of the debt; a reduction in the accrued interest; or re-aging, extensions, deferrals and renewals. TDR loans are considered impaired loans and are individually evaluated for impairment and can be classified as either accrual or nonaccrual. TDR loans are classified as nonperforming loans unless they have been performing in accordance with their modified terms for a period of at least six months in which case they are placed on accrual status. See “ Recent Accounting Pronouncements, Recent Events” below for payment deferrals considered to be short-term that are not considered TDRs.
Allowance for Loan and Lease Losses	Allowance for Loan and Lease Losses (“ALLL”) - When available information confirms that specific loans or portions thereof are uncollectible, these amounts are charged-off against the ALLL. The existence of some or all of the following criteria will generally confirm that a loss has been incurred: the loan is significantly delinquent and the borrower has not evidenced the ability or intent to bring the loan current; the Company has no recourse to the borrower, or if it does, the borrower has insufficient assets to pay the debt; the estimated fair value of the loan collateral is significantly below the current loan balance, and there is little or no near-term prospect for improvement. A provision for loan losses is charged against income and added to the ALLL based on regular assessment of the loan portfolio. The ALLL is allocated to certain loan categories based on the relative risk characteristics, asset classifications, and actual loss experience within the loan portfolio. Although management has allocated the ALLL to various loan portfolio segments, the allowance is general in nature and is available for the loan portfolio in its entirety. The ultimate recovery of all loans is susceptible to future market factors beyond the Company’s control. These factors may result in losses or recoveries differing significantly from those provided for in the financial statements. In addition, regulatory agencies, as an integral part of their examination process, periodically review the Company’s ALLL, and may require the Company to make additions to the allowance based on their judgment about information available to them at the time of their examinations.
Reserve for Unfunded Loan Commitments	Reserve for Unfunded Loan Commitments -
Premises and Equipment, Net	Premises and Equipment, Net - three Management reviews buildings, improvements and equipment for impairment on an annual basis or whenever events or changes in the circumstances indicate that the undiscounted cash flows for the property are less than its carrying value. If identified, an impairment loss is recognized through a charge to earnings based on the fair value of the property.
Right of Use Lease Asset & Lease Liability	Right of Use Lease Asset & Lease Liability - The Company leases retail space, office space, storage space, and equipment under operating leases. Most leases require the Company to pay real estate taxes, maintenance, insurance and other similar costs in addition to the base rent. Certain leases also contain lease incentives, such as tenant improvement allowances and rent abatement. Variable lease payments are recognized as lease expense as they are incurred. The Company records an operating lease right of use (ROU) asset and an operating lease liability (lease liability) for operating leases with a lease term greater than 12 months. The ROU asset and lease liability are recorded in other assets and other liabilities, respectively, in the consolidated statement of financial condition. ​ ROU assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company generally uses its incremental borrowing rate based on the estimated rate of interest for collateralized borrowing over a similar term of the lease payments at commencement date. Many of the Company’s leases contain various provisions for increases in rental rates, based either on changes in the published Consumer Price Index or a predetermined escalation schedule, which are factored into our determination of lease payments when appropriate. Substantially all of the leases provide the Company with the option to extend the lease term one or more times following expiration of the initial term. The ROU asset and lease liability terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term.
Transfers of Financial Assets and Servicing Rights	Transfers of Financial Assets - Servicing Rights - Servicing assets are evaluated quarterly for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights into tranches based on predominant characteristics, such as interest rate, loan type, and investor type. Impairment is recognized through a valuation allowance for an individual tranche, to the extent that fair value is less than the capitalized amount for the tranche. If the Company later determines that all or a portion of the impairment no longer exists for a particular tranche, a reduction of the allowance may be recorded as an increase to income. Capitalized servicing rights are stated separately on the Consolidated Balance Sheets and are amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets.
Income Taxes	Income Taxes - The Company follows the authoritative guidance issued related to accounting for uncertainty in income taxes. The guidance prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. It is the Company’s policy to record any penalties or interest arising from federal or state taxes as a component of income tax expense.
Employee Stock Ownership Plan	Employee Stock Ownership Plan -
Earnings Per Share	Earnings Per Share (“EPS”) -
Comprehensive Income (Loss)	Comprehensive Income (Loss) -
Financial Instruments	Financial Instruments -
Restricted Assets	Restricted Assets -
Marketing and Advertising Costs	Marketing and Advertising Costs -
Stock-Based Compensation	Stock-Based Compensation -
Goodwill	Goodwill -
Business Combinations	Business Combinations In the event that the fair value of net assets acquired exceeds the purchase price, including fair value of liabilities assumed, a bargain purchase gain is recorded on that acquisition.
Acquired Loans	Acquired Loans
Application of New Accounting Guidance in 2020	Application of New Accounting Guidance in 2020 On January 1, 2020, the Company adopted the Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU’) No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement ​ In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ​
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as amended by ASU 2018-19, ASU 2019-10, and ASU 2019-11. ​ The Company has selected a third-party vendor to assist in the implementation of this ASU and has run parallel computations as it continues to evaluate the impact of adoption of the new standard. As part of the implementation, management is also evaluating economic variables and forecast time horizons it believes to be most relevant based on the composition of the loan portfolio to develop a reasonable and supportable forecast, likely to include forecasted levels of employment, gross domestic product, and home price index, depending on the nature of the loan segment, as well as various loss methodologies to estimate expected credit losses. In addition, management has kept current on evolving interpretations and industry practices related to ASU 2016-13 via webcasts, publications, and conferences. Once adopted, the Company anticipates the allowance for loan losses to potentially increase through a one-time adjustment to retained earnings, however, until the evaluation is complete the magnitude of the potential increase will be unknown. ​ In April 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments In May 2019, the FASB issued ASU 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740), Simplifying the Accounting for Income Taxes ​ In October 2020, the FASB issued ASU 2020-08, Codification Improvements to Subtopic 310-20: Receivables – Nonrefundable Fees and Other Costs
Recent Events	​ Recent Events consumer loans of $392,000. The majority of these modifications involved short-term (e.g. less than six months) extensions and/or interest-only periods. On December 27, 2020, the Consolidated Appropriations Act (“CAA 2021”) was signed into law. Among other purposes, this act provides additional coronavirus emergency response and relief, including extending relief offered under the CARES Act related to troubled debt restructurings as a result of COVID-19 through January 1, 2022 or 60 days after the end of the national emergency declared by the President, whichever is earlier. For additional information, see “Note 3 - Loans Receivable and Allowance for Loan Losses.”
Loan Portfolio Segment	The Company has defined its loan portfolio into three segments that reflect the structure of the lending function, the Company’s strategic plan and the manner in which management monitors performance and credit quality. The three loan portfolio segments are: (a) Real Estate Loans, (b) Consumer Loans and (c) Commercial Business Loans. Each of these segments is disaggregated into classes based on the risk characteristics of the borrower and/or the collateral type securing the loan. The following is a summary of each of the Company’s loan portfolio segments and classes: Real Estate Loans Commercial Lending. Loans originated by the Company primarily secured by income producing properties, including retail centers, warehouses, and office buildings located in our market areas. Construction and Development Lending Home Equity Lending One-to-Four-Family Real Estate Lending Multi-family Lending Consumer Loans Indirect Home Improvement Marine. Other Consumer. Commercial Business Loans Commercial and Industrial Lending (“C&I”) Warehouse Lending
401 (k) Plan	401(k) Plan The Company has a salary deferral 401(k) Plan covering substantially all of its employees. Employees are eligible to participate in the 401(k) plan at the date of hire if they are 18 years of age. Eligible employees may contribute through payroll deductions and are 100% vested at all times in their deferral contributions account. The Company matches 100% for contributions of 1% to 3%, and 50% for contributions of 4% to 5%. There was a $1.5 million and $1.2 million matching contribution for the years ended December 31, 2020 and 2019, respectively.
Determination of Fair Market Values	The following methods were used to estimate the fair value of certain assets and liabilities on a recurring and nonrecurring basis. Securities Mortgage Loans Held for Sale - Derivative Instruments - Impaired Loans - Other Real Estate Owned Servicing Rights
Nonaccrual and Past Due Loans	Nonaccrual and Past Due Loans As a result of the negative impact on employment from the COVID-19 pandemic, the Company anticipates higher levels of financial hardship for its customers, which the Company expects will lead to higher levels of forbearance, delinquency and defaults until such time as the economy and employment return to relatively normal levels. The Company has and will continue to assist customers with an array of payment relief programs during periods of financial hardship, including forbearance. Forbearance allows a borrower to temporarily not make scheduled payments or to make smaller than scheduled payments, in each case for a specified period of time. Forbearance does not grant any reduction in the total principal or interest repayment obligation. While a loan is in forbearance status, interest continues to accrue and is repaid over a specified time period when the loan re-enters repayment status.
Loan Commitments	The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ ​ Estimated ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair SECURITIES AVAILABLE-FOR-SALE ​ Cost ​ Gains ​ Losses ​ Values U.S. agency securities ​ $ 7,940 ​ $ 166 ​ $ (1) ​ $ 8,105 Corporate securities ​ 11,885 ​ 54 ​ (939) ​ 11,000 Municipal bonds ​ 69,572 ​ 2,435 ​ (150) ​ 71,857 Mortgage-backed securities ​ 65,722 ​ 2,541 ​ (76) ​ 68,187 U.S. Small Business Administration securities ​ 18,441 ​ 443 ​ (15) ​ 18,869 Total securities available-for-sale ​ ​ 173,560 ​ ​ 5,639 ​ ​ (1,181) ​ ​ 178,018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SECURITIES HELD-TO-MATURITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate securities ​ ​ 7,500 ​ ​ 77 ​ ​ (21) ​ ​ 7,556 Total securities held-to-maturity ​ ​ 7,500 ​ ​ 77 ​ ​ (21) ​ ​ 7,556 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total securities ​ $ 181,060 ​ $ 5,716 ​ $ (1,202) ​ $ 185,574 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ ​ ​ Estimated ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair SECURITIES AVAILABLE-FOR-SALE ​ Cost ​ Gains ​ Losses ​ Values U.S. agency securities ​ $ 8,986 ​ $ 95 ​ $ (15) ​ $ 9,066 Corporate securities ​ 10,525 ​ 52 ​ (7) ​ 10,570 Municipal bonds ​ 20,516 ​ 604 ​ — ​ 21,120 Mortgage-backed securities ​ 62,745 ​ 405 ​ (300) ​ 62,850 U.S. Small Business Administration securities ​ 22,281 ​ 191 ​ (21) ​ 22,451 Total securities available-for-sale ​ $ 125,053 ​ $ 1,347 ​ $ (343) ​ $ 126,057
Schedule of Unrealized Loss on Investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ Less than 12 Months ​ 12 Months or Longer ​ Total ​ Fair Unrealized Fair Unrealized Fair Unrealized SECURITIES AVAILABLE-FOR-SALE ​ Value Losses ​ Value Losses ​ Value Losses U.S. agency securities ​ $ 1,986 ​ $ (1) ​ $ — ​ $ — ​ $ 1,986 ​ $ (1) Corporate securities ​ ​ 7,059 ​ ​ (939) ​ ​ — ​ ​ — ​ ​ 7,059 ​ ​ (939) Municipal bonds ​ ​ 8,377 ​ ​ (150) ​ ​ — ​ ​ — ​ ​ 8,377 ​ ​ (150) Mortgage-backed securities ​ 6,903 ​ (65) ​ 3,002 ​ ​ (11) ​ 9,905 ​ (76) U.S. Small Business Administration securities ​ 2,314 ​ (15) ​ — ​ — ​ 2,314 ​ (15) Total securities available-for-sale ​ ​ 26,639 ​ ​ (1,170) ​ ​ 3,002 ​ ​ (11) ​ ​ 29,641 ​ ​ (1,181) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SECURITIES HELD-TO-MATURITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate securities ​ ​ 4,979 ​ ​ (21) ​ ​ — ​ ​ — ​ ​ 4,979 ​ ​ (21) Total securities held-to-maturity ​ ​ 4,979 ​ ​ (21) ​ ​ — ​ ​ — ​ ​ 4,979 ​ ​ (21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 31,618 ​ $ (1,191) ​ $ 3,002 ​ $ (11) ​ $ 34,620 ​ $ (1,202) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ Less than 12 Months ​ 12 Months or Longer ​ Total ​ Fair Unrealized Fair Unrealized Fair Unrealized SECURITIES AVAILABLE-FOR-SALE Value Losses Value Losses Value Losses U.S. agency securities ​ $ 2,977 ​ $ (15) ​ $ — ​ $ — ​ $ 2,977 ​ $ (15) Corporate securities ​ 1,993 ​ (7) ​ — ​ — ​ 1,993 ​ (7) Mortgage-backed securities ​ 12,345 ​ (154) ​ 11,459 ​ (146) ​ 23,804 ​ (300) U.S. Small Business Administration securities ​ 4,395 ​ (21) ​ — ​ — ​ 4,395 ​ (21) Total ​ $ 21,710 ​ $ (197) ​ $ 11,459 ​ $ (146) ​ $ 33,169 ​ $ (343)
Schedule of Available for Sale Securities by Contractual Maturity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ December 31, 2019 SECURITIES AVAILABLE-FOR-SALE Amortized Fair Amortized Fair U.S. agency securities ​ Cost ​ Value ​ Cost ​ Value Due after one year through five years ​ $ 978 ​ $ 1,060 ​ $ 996 ​ $ 1,036 Due after five years through ten years ​ ​ 1,000 ​ ​ 1,036 ​ ​ 3,997 ​ ​ 4,027 Due after ten years ​ ​ 5,962 ​ ​ 6,009 ​ ​ 3,993 ​ ​ 4,003 Subtotal ​ 7,940 ​ 8,105 ​ 8,986 ​ 9,066 Corporate securities ​ ​ ​ ​ Due in one year or less ​ 2,392 ​ 2,433 ​ 5,034 ​ 5,044 Due after one year through five years ​ 3,493 ​ 3,491 ​ 3,491 ​ 3,532 Due after five years through ten years ​ ​ 4,000 ​ ​ 3,676 ​ ​ 2,000 ​ ​ 1,994 Due after ten years ​ ​ 2,000 ​ ​ 1,400 ​ ​ — ​ ​ — Subtotal ​ 11,885 ​ 11,000 ​ 10,525 ​ 10,570 Municipal bonds ​ ​ ​ ​ Due in one year or less ​ 101 ​ 101 ​ — ​ — Due after one year through five years ​ 3,749 ​ 3,980 ​ 3,774 ​ 3,833 Due after five years through ten years ​ 7,994 ​ 8,321 ​ 3,162 ​ 3,307 Due after ten years ​ 57,728 ​ 59,455 ​ 13,580 ​ 13,980 Subtotal ​ 69,572 ​ 71,857 ​ 20,516 ​ 21,120 Mortgage-backed securities ​ ​ ​ ​ Federal National Mortgage Association (“FNMA”) ​ 47,675 ​ 50,005 ​ 42,131 ​ 42,333 Federal Home Loan Mortgage Corporation (“FHLMC”) ​ 11,825 ​ 11,913 ​ 15,250 ​ 15,179 Government National Mortgage Association (“GNMA”) ​ 6,222 ​ 6,269 ​ 5,364 ​ 5,338 Subtotal ​ 65,722 ​ 68,187 ​ 62,745 ​ 62,850 U.S. Small Business Administration securities ​ ​ ​ ​ Due after one year through five years ​ 2,266 ​ 2,353 ​ 1,546 ​ 1,555 Due after five years through ten years ​ ​ 8,097 ​ ​ 8,333 ​ ​ 11,500 ​ ​ 11,598 Due after ten years ​ ​ 8,078 ​ ​ 8,183 ​ ​ 9,235 ​ ​ 9,298 Subtotal ​ ​ 18,441 ​ ​ 18,869 ​ ​ 22,281 ​ ​ 22,451 Total securities available-for-sale ​ ​ 173,560 ​ ​ 178,018 ​ ​ 125,053 ​ ​ 126,057 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ SECURITIES HELD-TO-MATURITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Due after five years through ten years ​ ​ 7,500 ​ ​ 7,556 ​ ​ — ​ ​ — Total securities held-to-maturity ​ ​ 7,500 ​ ​ 7,556 ​ ​ — ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total securities ​ $ 181,060 ​ $ 185,574 ​ $ 125,053 ​ $ 126,057
Schedule of Realized Gain (Loss)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Proceeds Gross Gains Gross Losses Securities available-for-sale ​ $ 12,214 ​ $ 300 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Proceeds Gross Gains Gross Losses Securities available-for-sale ​ $ 10,554 ​ $ 91 ​ $ (59)

Loans Receivable and Allowanc_2

Loans Receivable and Allowance For Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, REAL ESTATE LOANS ​ 2020 2019 Commercial ​ $ 222,719 ​ $ 210,749 Construction and development ​ 216,975 ​ 179,654 Home equity ​ 43,093 ​ 38,167 One-to-four-family (excludes loans held for sale) ​ 311,093 ​ 261,539 Multi-family ​ 131,601 ​ 133,931 Total real estate loans ​ 925,481 ​ 824,040 CONSUMER LOANS ​ ​ ​ Indirect home improvement ​ 286,020 ​ 254,691 Marine ​ 85,740 ​ 67,179 Other consumer ​ 3,418 ​ 4,340 Total consumer loans ​ 375,178 ​ 326,210 COMMERCIAL BUSINESS LOANS ​ ​ ​ Commercial and industrial ​ 224,476 ​ 140,531 Warehouse lending ​ 49,092 ​ 61,112 Total commercial business loans ​ 273,568 ​ 201,643 Total loans receivable, gross ​ 1,574,227 ​ 1,351,893 Allowance for loan losses ​ (26,172) ​ (13,229) Deferred costs and fees, net ​ ​ (4,017) ​ ​ (3,273) Premiums on purchased loans, net ​ 943 ​ 955 Total loans receivable, net ​ $ 1,544,981 ​ $ 1,336,346
Allowance for Credit Losses on Financing Receivables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2020 ​ ​ ​ ​ ​ Commercial ​ ​ ​ ​ ALLOWANCE FOR LOAN LOSSES ​ Real Estate ​ Consumer ​ Business ​ Unallocated ​ Total Beginning balance ​ $ 6,206 ​ $ 3,766 ​ $ 3,254 ​ $ 3 ​ $ 13,229 Provision for loan losses ​ 7,622 ​ 3,372 ​ 1,354 ​ 688 ​ 13,036 Charge-offs ​ — ​ (1,101) ​ (22) ​ — ​ (1,123) Recoveries ​ 18 ​ 659 ​ 353 ​ — ​ 1,030 Net recoveries (charge-offs) ​ 18 ​ (442) ​ 331 ​ — ​ (93) Ending balance ​ $ 13,846 ​ $ 6,696 ​ $ 4,939 ​ $ 691 ​ $ 26,172 Period end amount allocated to: ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 15 ​ $ 305 ​ $ 990 ​ $ — ​ $ 1,310 Loans collectively evaluated for impairment ​ 13,831 ​ 6,391 ​ 3,949 ​ 691 ​ 24,862 Ending balance ​ $ 13,846 ​ $ 6,696 ​ $ 4,939 ​ $ 691 ​ $ 26,172 LOANS RECEIVABLE ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 1,280 ​ $ 871 ​ $ 5,610 ​ $ — ​ $ 7,761 Loans collectively evaluated for impairment ​ 924,201 ​ 374,307 ​ 267,958 ​ — ​ 1,566,466 Ending balance ​ $ 925,481 ​ $ 375,178 ​ $ 273,568 ​ $ — ​ $ 1,574,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2019 ​ ​ ​ ​ ​ Commercial ​ ​ ​ ​ ALLOWANCE FOR LOAN LOSSES ​ Real Estate ​ Consumer ​ Business ​ Unallocated ​ Total Beginning balance ​ $ 5,761 ​ $ 3,351 ​ $ 3,191 ​ $ 46 ​ $ 12,349 Provision (recapture) for loan losses ​ 439 ​ 838 ​ 1,646 ​ (43) ​ 2,880 Charge-offs ​ (5) ​ (1,040) ​ (1,583) ​ — ​ (2,628) Recoveries ​ 11 ​ 617 ​ — ​ — ​ 628 Net recoveries (charge-offs) ​ 6 ​ (423) ​ (1,583) ​ — ​ (2,000) Ending balance ​ $ 6,206 ​ $ 3,766 ​ $ 3,254 ​ $ 3 ​ $ 13,229 Period end amount allocated to: ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 15 ​ $ 167 ​ $ — ​ $ — ​ $ 182 Loans collectively evaluated for impairment ​ 6,191 ​ 3,599 ​ 3,254 ​ 3 ​ 13,047 Ending balance ​ $ 6,206 ​ $ 3,766 ​ $ 3,254 ​ $ 3 ​ $ 13,229 LOANS RECEIVABLE ​ ​ ​ ​ ​ Loans individually evaluated for impairment ​ $ 2,635 ​ $ 493 ​ $ — ​ $ — ​ $ 3,128 Loans collectively evaluated for impairment ​ 821,405 ​ 325,717 ​ 201,643 ​ — ​ 1,348,765 Ending balance ​ $ 824,040 ​ $ 326,210 ​ $ 201,643 ​ $ — ​ $ 1,351,893
Past Due Financing Receivables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ 30-59 60-89 ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ 90 Days ​ Total ​ ​ ​ Total ​ ​ ​ ​ Past ​ Past ​ or More ​ Past ​ ​ ​ Loans ​ Non- REAL ESTATE LOANS ​ Due ​ Due ​ Past Due ​ Due ​ Current ​ Receivable ​ Accrual Commercial ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 222,719 ​ $ 222,719 ​ $ — Construction and development ​ 1,850 ​ — ​ — ​ 1,850 ​ 215,125 ​ 216,975 ​ — Home equity ​ 127 ​ 137 ​ 219 ​ 483 ​ 42,610 ​ 43,093 ​ 636 One-to-four-family ​ 389 ​ 404 ​ 512 ​ 1,305 ​ 309,788 ​ 311,093 ​ 644 Multi-family ​ — ​ — ​ — ​ — ​ 131,601 ​ 131,601 ​ — Total real estate loans ​ 2,366 ​ 541 ​ 731 ​ 3,638 ​ 921,843 ​ 925,481 ​ 1,280 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 683 ​ 331 ​ 325 ​ 1,339 ​ 284,681 ​ 286,020 ​ 826 Marine ​ 28 ​ 77 ​ 22 ​ 127 ​ 85,613 ​ 85,740 ​ 44 Other consumer ​ 73 ​ 22 ​ — ​ 95 ​ 3,323 ​ 3,418 ​ 1 Total consumer loans ​ 784 ​ 430 ​ 347 ​ 1,561 ​ 373,617 ​ 375,178 ​ 871 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ — ​ 1,204 ​ — ​ 1,204 ​ 223,272 ​ 224,476 ​ 5,610 Warehouse lending ​ — ​ — ​ — ​ — ​ 49,092 ​ 49,092 ​ — Total commercial business loans ​ — ​ 1,204 ​ — ​ 1,204 ​ 272,364 ​ 273,568 ​ 5,610 Total loans ​ $ 3,150 ​ $ 2,175 ​ $ 1,078 ​ $ 6,403 ​ $ 1,567,824 ​ $ 1,574,227 ​ $ 7,761 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ 30-59 60-89 ​ ​ ​ ​ ​ ​ ​ Days ​ Days ​ 90 Days ​ Total ​ ​ ​ Total ​ ​ ​ ​ Past ​ Past ​ or More ​ Past ​ ​ ​ Loans ​ Non- REAL ESTATE LOANS ​ Due ​ Due ​ Past Due ​ Due ​ Current ​ Receivable ​ Accrual Commercial ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 210,749 ​ $ 210,749 ​ $ 1,086 Construction and development ​ 533 ​ — ​ — ​ 533 ​ 179,121 ​ 179,654 ​ — Home equity ​ 109 ​ — ​ 185 ​ 294 ​ 37,873 ​ 38,167 ​ 190 One-to-four-family ​ 894 ​ 114 ​ 1,150 ​ 2,158 ​ 259,381 ​ 261,539 ​ 1,264 Multi-family ​ — ​ — ​ — ​ — ​ 133,931 ​ 133,931 ​ — Total real estate loans ​ 1,536 ​ 114 ​ 1,335 ​ 2,985 ​ 821,055 ​ 824,040 ​ 2,540 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 692 ​ 227 ​ 147 ​ 1,066 ​ 253,625 ​ 254,691 ​ 468 Marine ​ 15 ​ — ​ — ​ 15 ​ 67,164 ​ 67,179 ​ — Other consumer ​ 71 ​ 2 ​ 20 ​ 93 ​ 4,247 ​ 4,340 ​ 25 Total consumer loans ​ 778 ​ 229 ​ 167 ​ 1,174 ​ 325,036 ​ 326,210 ​ 493 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ — ​ — ​ — ​ — ​ 140,531 ​ 140,531 ​ — Warehouse lending ​ — ​ — ​ — ​ — ​ 61,112 ​ 61,112 ​ — Total commercial business loans ​ — ​ — ​ — ​ — ​ 201,643 ​ 201,643 ​ — Total loans ​ $ 2,314 ​ $ 343 ​ $ 1,502 ​ $ 4,159 ​ $ 1,347,734 ​ $ 1,351,893 ​ $ 3,033
Impaired Financing Receivables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Unpaid ​ ​ ​ ​ WITH NO RELATED ALLOWANCE RECORDED ​ Principal ​ Recorded ​ Related Real estate loans: ​ Balance ​ Investment ​ Allowance Home equity ​ $ 687 ​ $ 636 ​ $ — One-to-four-family ​ ​ 645 ​ ​ 584 ​ ​ — Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ 1,203 ​ 1,203 ​ ​ — ​ ​ ​ 2,535 ​ ​ 2,423 ​ ​ — WITH RELATED ALLOWANCE RECORDED ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-four-family ​ ​ 61 ​ ​ 60 ​ ​ 15 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Indirect ​ ​ 826 ​ ​ 826 ​ ​ 289 Marine ​ ​ 44 ​ ​ 44 ​ ​ 15 Other consumer ​ ​ 1 ​ ​ 1 ​ ​ 1 Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ ​ 4,407 ​ ​ 4,407 ​ ​ 990 ​ ​ ​ 5,339 ​ ​ 5,338 ​ ​ 1,310 Total ​ $ 7,874 ​ $ 7,761 ​ $ 1,310 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Unpaid ​ ​ ​ ​ WITH NO RELATED ALLOWANCE RECORDED ​ Principal ​ Recorded ​ Related Real estate loans: ​ Balance ​ Investment ​ Allowance Commercial ​ $ 1,097 ​ $ 1,086 ​ $ — Home equity ​ ​ 278 ​ ​ 225 ​ ​ — One-to-four-family ​ ​ 1,293 ​ ​ 1,264 ​ ​ — Consumer loans ​ ​ ​ ​ ​ ​ ​ ​ ​ Other consumer ​ ​ 17 ​ ​ 17 ​ ​ — ​ ​ ​ 2,685 ​ 2,592 ​ ​ — WITH RELATED ALLOWANCE RECORDED ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-four-family ​ ​ 61 ​ ​ 60 ​ ​ 15 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ Indirect ​ ​ 468 ​ ​ 468 ​ ​ 164 Other consumer ​ ​ 8 ​ ​ 8 ​ ​ 3 ​ ​ ​ 537 ​ ​ 536 ​ ​ 182 Total ​ $ 3,222 ​ $ 3,128 ​ $ 182 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended ​ ​ December 31, 2020 ​ December 31, 2019 WITH NO RELATED ALLOWANCE RECORDED Average Recorded Interest Income Average Recorded Interest Income Real estate loans: ​ Investment ​ Recognized ​ Investment ​ Recognized Commercial ​ $ 996 ​ $ — ​ $ 90 ​ $ 56 Home equity ​ ​ 485 ​ ​ 25 ​ ​ 206 ​ ​ 3 One-to-four-family ​ 954 ​ 17 ​ 1,500 ​ 34 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other consumer ​ ​ 3 ​ ​ — ​ ​ 4 ​ ​ 2 Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ ​ 100 ​ ​ 37 ​ ​ 180 ​ ​ — ​ ​ ​ 2,538 ​ ​ 79 ​ ​ 1,980 ​ ​ 95 WITH AN ALLOWANCE RECORDED ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Real estate loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ One-to-four-family ​ ​ 60 ​ ​ — ​ ​ 5 ​ ​ 5 Consumer loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Indirect ​ ​ 675 ​ ​ 60 ​ ​ 463 ​ ​ 42 Marine ​ ​ 40 ​ ​ 3 ​ ​ 13 ​ ​ — Other consumer ​ ​ 1 ​ ​ — ​ ​ 5 ​ ​ 1 Commercial business loans: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ ​ 2,531 ​ ​ 162 ​ ​ 96 ​ ​ — ​ ​ ​ 3,307 ​ ​ 225 ​ ​ 582 ​ ​ 48 Total ​ $ 5,845 ​ $ 304 ​ $ 2,562 ​ $ 143
Financing Receivable Credit Quality Indicators	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ Special ​ ​ ​ ​ ​ ​ Pass ​ Watch ​ Mention ​ Substandard ​ Doubtful ​ Loss ​ ​ REAL ESTATE LOANS ​ (1 - 5) ​ (6) ​ (7) ​ (8) ​ (9) ​ (10) ​ Total Commercial ​ $ 157,932 ​ $ 60,834 ​ $ 3,013 ​ $ 940 ​ $ — ​ $ — ​ $ 222,719 Construction and development ​ 212,209 ​ 2,917 ​ 1,849 ​ — ​ — ​ — ​ 216,975 Home equity ​ 42,457 ​ — ​ — ​ 636 ​ — ​ — ​ 43,093 One-to-four-family ​ 303,610 ​ 162 ​ 187 ​ 7,134 ​ — ​ — ​ 311,093 Multi-family ​ 131,601 ​ — ​ — ​ — ​ — ​ — ​ 131,601 Total real estate loans ​ 847,809 ​ 63,913 ​ 5,049 ​ 8,710 ​ — ​ — ​ 925,481 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 285,194 ​ — ​ — ​ 826 ​ — ​ — ​ 286,020 Marine ​ 85,696 ​ — ​ — ​ 44 ​ — ​ — ​ 85,740 Other consumer ​ 3,417 ​ — ​ — ​ 1 ​ — ​ — ​ 3,418 Total consumer loans ​ 374,307 ​ — ​ — ​ 871 ​ — ​ — ​ 375,178 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ 190,392 ​ 23,945 ​ 2,073 ​ 8,066 ​ — ​ — ​ 224,476 Warehouse lending ​ 49,092 ​ — ​ — ​ — ​ — ​ — ​ 49,092 Total commercial business loans ​ 239,484 ​ 23,945 ​ 2,073 ​ 8,066 ​ — ​ — ​ 273,568 Total loans receivable, gross ​ $ 1,461,600 ​ $ 87,858 ​ $ 7,122 ​ $ 17,647 ​ $ — ​ $ — ​ $ 1,574,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ ​ Special ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pass ​ Watch ​ Mention ​ Substandard ​ Doubtful ​ Loss ​ ​ REAL ESTATE LOANS (1 - 5) (6) (7) (8) (9) (10) Total Commercial ​ $ 203,703 ​ $ 2,274 ​ $ 3,686 ​ $ 1,086 ​ $ — ​ $ — ​ $ 210,749 Construction and development ​ 177,109 ​ 2,545 ​ — ​ — ​ — ​ — ​ 179,654 Home equity ​ 37,942 ​ — ​ 35 ​ 190 ​ — ​ — ​ 38,167 One-to-four-family ​ 259,580 ​ 635 ​ 60 ​ 1,264 ​ — ​ — ​ 261,539 Multi-family ​ 127,792 ​ 6,139 ​ — ​ — ​ — ​ — ​ 133,931 Total real estate loans ​ 806,126 ​ 11,593 ​ 3,781 ​ 2,540 ​ — ​ — ​ 824,040 CONSUMER LOANS ​ ​ ​ ​ ​ ​ ​ Indirect home improvement ​ 254,223 ​ — ​ — ​ 468 ​ — ​ — ​ 254,691 Marine ​ 67,179 ​ — ​ — ​ — ​ — ​ — ​ 67,179 Other consumer ​ 4,315 ​ — ​ — ​ 25 ​ — ​ — ​ 4,340 Total consumer loans ​ 325,717 ​ — ​ — ​ 493 ​ — ​ — ​ 326,210 COMMERCIAL BUSINESS LOANS ​ ​ ​ ​ ​ ​ ​ Commercial and industrial ​ 125,025 ​ 10,435 ​ 1,442 ​ 3,629 ​ — ​ — ​ 140,531 Warehouse lending ​ 61,112 ​ — ​ — ​ — ​ — ​ — ​ 61,112 Total commercial business loans ​ 186,137 ​ 10,435 ​ 1,442 ​ 3,629 ​ — ​ — ​ 201,643 Total loans receivable, gross ​ $ 1,317,980 ​ $ 22,028 ​ $ 5,223 ​ $ 6,662 ​ $ — ​ $ — ​ $ 1,351,893
Schedule of Related Party Loans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, ​ 2020 2019 Beginning balance ​ $ 3,249 ​ $ 3,325 Additions ​ 581 ​ — Repayments ​ (33) ​ (76) Ending balance ​ $ 3,797 ​ $ 3,249

Servicing Rights (Tables)

Servicing Rights (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Summary of servicing rights activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended ​ ​ December 31, ​ 2020 2019 Beginning balance ​ $ 11,560 ​ $ 10,429 Additions ​ 11,139 ​ 5,400 Servicing rights amortized ​ (8,135) ​ (4,177) Impairment of servicing rights ​ ​ (1,969) ​ ​ (92) Ending balance ​ $ 12,595 ​ $ 11,560
Key economic assumptions and the sensitivity of the current fair value for single family mortgage servicing rights	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 December 31, 2019 Aggregate portfolio principal balance (1) ​ $ 2,133,473 $ 1,463,732 ​ Weighted average rate of note ​ ​ 3.5 % ​ 4.2 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2020 Base 0.5% Adverse Rate Change 1.0% Adverse Rate Change ​ Conditional prepayment rate ​ 32.6 % ​ 40.6 % ​ 59.6 % Fair value MSR ​ $ 12,833 $ 10,922 $ 8,286 ​ Percentage of MSR ​ 0.6 % 0.5 % 0.4 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 9.1 % 9.6 % 10.1 % Fair value MSR ​ $ 12,833 $ 12,696 $ 12,562 ​ Percentage of MSR ​ 0.6 % 0.6 % 0.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2019 ​ Base 0.5% Adverse Rate Change 1.0% Adverse Rate Change ​ Conditional prepayment rate ​ 17.1 % ​ 24.6 % ​ 32.5 % Fair value MSR ​ $ 13,255 $ 10,582 $ 8,674 ​ Percentage of MSR ​ 0.9 % 0.7 % 0.6 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 9.7 % 10.2 % 10.7 % Fair value MSR ​ $ 13,255 $ 13,037 $ 12,826 ​ Percentage of MSR ​ 0.9 % 0.9 % 0.9 % _______________________________ (1) Excludes nonperforming serviced loans in forbearance.
Mortgage servicing rights
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Valuation assumptions	​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, ​ At December 31, Key assumptions: 2020 2019 ​ Weighted average discount rate 9.1 % 9.7 % Conditional prepayment rate (“CPR”) 32.6 % 17.1 % Weighted average life in years 3.0 5.1 ​

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Premises and Equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Land ​ $ 5,227 ​ $ 5,227 Buildings ​ 16,769 ​ 16,769 Furniture, fixtures, and equipment ​ 14,724 ​ 13,562 Leasehold improvements ​ 2,859 ​ 2,848 Building improvements ​ 6,830 ​ 6,572 Projects in process ​ 355 ​ 407 Subtotal ​ 46,764 ​ 45,385 Less accumulated depreciation and amortization ​ (19,421) ​ (16,615) Total ​ $ 27,343 ​ $ 28,770

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Summary of lease cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended Lease cost: December 31, 2020 December 31, 2019 Operating lease cost ​ $ 1,393 ​ $ 1,285 Short-term lease cost ​ 11 ​ 166 Total lease cost ​ $ 1,404 ​ $ 1,451
Supplemental information related to operating leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the ​ At or For the Cash paid for amounts included in the ​ Year Ended ​ Year Ended measurement of lease liabilities: December 31, 2020 December 31, 2019 Operating cash flows from operating leases ​ $ 1,365 ​ ​ $ 1,331 ​ Weighted average remaining lease term- operating leases ​ ​ 5.4 years ​ 5.3 years Weighted average discount rate- operating leases ​ ​ 2.48 % ​ 3.00 %
Summary of maturities of operating lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ 2021 $ 1,319 2022 ​ 1,222 2023 ​ 839 2024 ​ ​ 787 2025 ​ ​ 478 Thereafter ​ 949 Total lease payments ​ ​ 5,594 Less imputed interest ​ ​ (418) Total ​ $ 5,176

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2020
Banking and Thrift [Abstract]
Schedule of Other Real Estate Owned	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended ​ ​ December 31, ​ 2020 2019 Beginning balance ​ $ 168 ​ $ 689 Additions ​ — ​ 242 Gross proceeds from sale of OREO ​ (76) ​ (901) (Loss) gain on sale of OREO ​ (2) ​ 138 Ending balance ​ $ 90 ​ $ 168

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2020
Banking and Thrift [Abstract]
Schedule of Deposit Liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2020 2019 Noninterest-bearing checking ​ $ 348,421 ​ $ 260,131 Interest-bearing checking ​ 226,282 ​ 177,972 Savings ​ 152,842 ​ 118,845 Money market ​ 429,548 ​ 270,489 Certificates of deposit less than $100,000 ​ 299,157 ​ 277,988 Certificates of deposit of $100,000 through $250,000 ​ 135,901 ​ 181,402 Certificates of deposit of $250,000 and over ​ 67,488 ​ 92,110 Escrow accounts related to mortgages serviced ​ 14,432 ​ 13,471 Total ​ $ 1,674,071 ​ $ 1,392,408
Schedule of Maturities of Time Deposits for Future Periods	​ ​ ​ ​ ​ ​ At December 31, 2020 Maturing in 2021 ​ $ 340,867 Maturing in 2022 ​ ​ 88,529 Maturing in 2023 ​ ​ 19,991 Maturing in 2024 ​ ​ 20,131 Maturing in 2025 ​ ​ 33,027 Thereafter ​ ​ 1 Total ​ $ 502,546
Schedule of Interest Expense by Deposit Category	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2020 2019 Interest-bearing checking ​ $ 388 ​ $ 1,414 Savings and money market ​ 2,458 ​ 3,098 Certificates of deposit ​ 9,134 ​ 11,650 Total ​ $ 11,980 ​ $ 16,162

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Advances on Borrowing Line	​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Federal Home Loan Bank ​ $ 102,528 ​ $ 84,864 Paycheck Protection Program Liquidity Facility ​ ​ 63,281 ​ ​ — Total ​ $ 165,809 ​ $ 84,864
Debt with Maximum and Average Balances	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Maximum balance: ​ ​ ​ Federal Home Loan Bank advances and Fed Funds ​ $ 159,114 ​ $ 186,401 ​ Federal Reserve Bank ​ $ 40,000 ​ $ 5,000 ​ Fed Funds lines of credit ​ $ 865 ​ $ 5,000 ​ Subordinated note ​ $ 10,000 ​ $ 10,000 ​ Paycheck Protection Program Liquidity Facility ​ $ 74,112 ​ $ — ​ Average balance: ​ ​ ​ Federal Home Loan Bank advances and Fed Funds ​ $ 99,773 ​ $ 93,653 ​ Federal Reserve Bank ​ $ 1,096 ​ $ 167 ​ Fed Funds lines of credit ​ $ 3 ​ $ 318 ​ Subordinated note ​ $ 10,000 ​ $ 10,000 ​ Paycheck Protection Program Liquidity Facility ​ $ 46,965 ​ $ — ​ Weighted average interest rates ​ ​ ​ Federal Home Loan Bank advances and Fed Funds ​ 1.80 % 2.61 % Fed Funds ​ 0.25 % 2.96 % Fed Funds lines of credit ​ 0.36 % 2.09 % Subordinated note ​ ​ 6.50 % ​ 6.50 % Paycheck Protection Program Liquidity Facility ​ 0.35 % — %
Schedule of Federal Home Loan Bank Advances Maturities Summary Due	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest Years Ending December 31, Balances Rates 2021 ​ $ 75,000 1.60 % 2022 ​ 13,633 2.03 % 2023 ​ 13,895 1.77 % Total ​ $ 102,528 ​

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2020
Compensation and Retirement Disclosure [Abstract]
Schedule of Shares Under ESOP	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances ​ Balances ​ at December 31, 2020 at December 31, 2019 Allocated shares ​ ​ 213,744 ​ ​ 189,511 Committed to be released shares ​ — ​ — Unallocated shares ​ 25,921 ​ 51,842 Total ESOP shares ​ 239,665 ​ 241,353 ​ ​ ​ ​ ​ ​ ​ Fair value of unallocated shares (in thousands) ​ $ 1,307 ​ $ 3,006

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
INCOME TAXES
Schedule of Components of Income Tax Expense (Benefit)	​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 2019 Provision for income taxes ​ ​ Current ​ $ 12,976 ​ $ 4,425 Deferred ​ (2,390) ​ 988 Total provision for income taxes ​ $ 10,586 ​ $ 5,413
Schedule of Effective Income Tax Rate Reconciliation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2020 ​ 2019 ​ ​ Amount ​ Rate ​ Amount ​ Rate Income tax provision at statutory rate $ 10,469 21.0 % $ 5,907 21.0 % Tax exempt income ​ (292) (0.6) ​ (225) (0.8) ​ Nondeductible items resulting in increase in tax ​ ​ 57 ​ 0.1 ​ ​ 129 ​ 0.5 ​ Increase (decrease) in tax resulting from other items ​ 175 0.4 ​ (78) (0.3) ​ Equity compensation ​ ​ (46) ​ (0.1) ​ ​ (691) ​ (2.5) ​ Executive compensation ​ ​ 8 ​ — ​ ​ 112 ​ 0.4 ​ ESOP ​ 215 0.4 ​ 259 0.9 ​ Total ​ $ 10,586 21.2 % $ 5,413 19.2 %
Schedule of Deferred Tax Assets and Liabilities	​ ​ ​ ​ ​ ​ ​ ​ Deferred Tax Assets 2020 2019 Net operating loss carryforward ​ $ 527 ​ $ 864 Allowance for loan losses ​ ​ 5,775 ​ ​ 2,844 Purchase accounting adjustments ​ ​ — ​ ​ 466 Other real estate owned ​ ​ 126 ​ ​ 126 Nonaccrued loan interest ​ 6 ​ 13 Restricted stock awards ​ 97 ​ 68 Non-qualified stock options ​ 251 ​ 185 Interest rate swaps designated as cash flow hedge ​ 265 ​ — Lease liability ​ ​ 1,113 ​ ​ 1,121 Accrued compensation ​ ​ 430 ​ ​ — Other ​ 224 ​ 351 Total deferred tax assets ​ 8,814 ​ 6,038 Deferred Tax Liabilities ​ ​ Loan origination costs ​ (2,134) ​ (1,341) Servicing rights ​ (2,708) ​ (2,525) Stock dividend - FHLB stock ​ (55) ​ (59) Property, plant, and equipment ​ (1,097) ​ (1,362) Purchase accounting adjustments ​ ​ (830) ​ ​ (1,404) Securities available-for-sale ​ ​ (958) ​ ​ (216) Lease right-of-use assets ​ ​ (1,090) ​ ​ (1,078) Other ​ ​ — ​ ​ (24) Total deferred tax liabilities ​ (8,872) ​ (8,009) Net deferred tax liabilities ​ $ (58) ​ $ (1,971)

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of Commitments to Extend Credit	​ ​ ​ ​ ​ ​ ​ ​ COMMITMENTS TO EXTEND CREDIT December 31, December 31, REAL ESTATE LOANS ​ 2020 2019 Commercial ​ $ 1,293 ​ $ 247 Construction and development ​ 143,666 ​ 95,031 One-to-four-family (includes locks for saleable loans) ​ 147,712 ​ 39,697 Home equity ​ 52,457 ​ 47,880 Multi-family ​ 658 ​ 622 Total real estate loans ​ 345,786 ​ 183,477 CONSUMER LOANS ​ 23,365 ​ 22,176 COMMERCIAL BUSINESS LOANS ​ ​ Commercial and industrial ​ 106,171 ​ 72,731 Warehouse lending ​ 52,909 ​ 33,888 Total commercial business loans ​ 159,080 ​ 106,619 Total commitments to extend credit ​ $ 528,231 ​ $ 312,272

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of assets and liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Financial Assets ​ At December 31, 2020 Securities available-for-sale: Level 1 Level 2 Level 3 Total U.S. agency securities ​ $ — ​ $ 8,105 ​ $ — ​ $ 8,105 Corporate securities ​ — ​ 10,016 ​ 984 ​ 11,000 Municipal bonds ​ — ​ 71,730 ​ 127 ​ 71,857 Mortgage-backed securities ​ — ​ 68,187 ​ — ​ 68,187 U.S. Small Business Administration securities ​ — ​ 18,869 ​ — ​ 18,869 Mortgage loans held for sale, at fair value ​ ​ — ​ ​ 166,448 ​ ​ — ​ ​ 166,448 Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps ​ ​ — ​ ​ 21 ​ ​ — ​ ​ 21 Interest rate lock commitments with customers ​ ​ — ​ ​ — ​ ​ 4,024 ​ ​ 4,024 Total assets measured at fair value ​ $ — ​ $ 343,376 ​ $ 5,135 ​ $ 348,511 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mandatory and best effort forward commitments with investors ​ $ — ​ $ — ​ $ (67) ​ $ (67) Forward TBA mortgage-backed securities ​ ​ — ​ ​ (1,602) ​ ​ — ​ ​ (1,602) Interest rate swaps ​ ​ — ​ ​ (1,252) ​ ​ — ​ ​ (1,252) Total liabilities measured at fair value ​ $ — ​ $ (2,854) ​ $ (67) ​ $ (2,921) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Financial Assets ​ At December 31, 2019 Securities available-for-sale: Level 1 Level 2 Level 3 Total U.S. agency securities ​ $ — ​ $ 9,066 ​ $ — ​ $ 9,066 Corporate securities ​ — ​ 9,546 ​ 1,024 ​ 10,570 Municipal bonds ​ — ​ 20,982 ​ 138 ​ 21,120 Mortgage-backed securities ​ — ​ 62,850 ​ — ​ 62,850 U.S. Small Business Administration securities ​ — ​ 22,451 ​ — ​ 22,451 Mortgage loans held for sale, at fair value ​ ​ — ​ ​ 69,699 ​ ​ — ​ ​ 69,699 Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate lock commitments with customers ​ ​ — ​ ​ — ​ ​ 557 ​ ​ 557 Total assets measured at fair value ​ $ — ​ $ 194,594 ​ $ 1,719 ​ $ 196,313 Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mandatory and best effort forward commitments with investors ​ $ — ​ $ — ​ $ (195) ​ $ (195) Forward TBA mortgage-backed securities ​ ​ — ​ ​ (8) ​ ​ — ​ ​ (8) Total liabilities measured at fair value ​ $ — ​ $ (8) ​ $ (195) ​ $ (203)
Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Level 1 Level 2 Level 3 Total Impaired loans ​ $ — $ — $ 7,761 $ 7,761 OREO ​ ​ — ​ ​ — ​ ​ 90 ​ ​ 90 Servicing rights ​ ​ — ​ — ​ 12,833 ​ 12,833 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ Level 1 Level 2 Level 3 Total Impaired loans ​ $ — $ — $ 3,128 $ 3,128 OREO ​ ​ — ​ ​ — ​ ​ 168 ​ ​ 168 Servicing rights ​ ​ — ​ — ​ 13,255 ​ 13,255
Fair value reconciliation - Level 3 on recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Purchases ​ ​ ​ Net change in Net change in ​ Beginning and Sales and Transfers Ending fair value for fair value for 2020 Balance Issuances Settlements In Balance gains/(losses) (1) gains/(losses) (2) Interest rate lock commitments with customers ​ $ 557 ​ $ 53,281 ​ $ (49,814) ​ $ — ​ $ 4,024 ​ $ 3,467 ​ $ — Individual forward sale commitments with investors ​ ​ (195) ​ ​ (4,857) ​ ​ 4,985 ​ ​ — ​ ​ (67) ​ ​ 128 ​ ​ — Securities available-for-sale, at fair value ​ ​ 1,162 ​ ​ — ​ ​ (51) ​ ​ — ​ ​ 1,111 ​ ​ — ​ ​ (40) 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate lock commitments with customers ​ $ 503 ​ $ 11,063 ​ $ (11,009) ​ $ — ​ $ 557 ​ $ 54 ​ $ — Individual forward sale commitments with investors ​ ​ (34) ​ ​ (1,444) ​ ​ 1,283 ​ ​ — ​ ​ (195) ​ ​ (161) ​ ​ — Securities available-for-sale, at fair value ​ ​ — ​ ​ — ​ ​ — ​ ​ 1,162 ​ ​ 1,162 ​ ​ — ​ ​ — _____________________________ (1) Relating to items held at end of period included in income. (2) Relating to items held at end of period included in other comprehensive income.
Fair Value, by Balance Sheet Grouping	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ 2020 ​ 2019 ​ Financial Assets Carrying Fair Carrying Fair ​ Level 1 inputs: Amount Value Amount Value ​ Cash and cash equivalents ​ $ 91,576 ​ $ 91,576 ​ $ 45,778 ​ $ 45,778 ​ Certificates of deposit at other financial institutions ​ 12,278 ​ 12,278 ​ 20,902 ​ 20,902 ​ Level 2 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities available-for-sale, at fair value ​ 176,907 ​ 176,907 ​ 124,895 ​ 124,895 ​ Securities held-to-maturity ​ ​ 7,500 ​ ​ 7,556 ​ ​ — ​ ​ — ​ Loans held for sale, at fair value ​ 166,448 ​ 166,448 ​ 69,699 ​ 69,699 ​ FHLB stock, at cost ​ 7,439 ​ 7,439 ​ 8,045 ​ 8,045 ​ Interest rate swaps ​ ​ 21 ​ ​ 21 ​ ​ — ​ ​ — ​ Accrued interest receivable ​ 7,030 ​ 7,030 ​ 5,908 ​ 5,908 ​ Level 3 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Securities available-for-sale, at fair value ​ ​ 1,111 ​ ​ 1,111 ​ ​ 1,162 ​ ​ 1,162 ​ Loans receivable, gross ​ 1,574,227 ​ 1,580,360 ​ 1,351,893 ​ 1,377,408 ​ Servicing rights, held at lower of cost or fair value ​ 12,595 ​ 12,833 ​ 11,560 ​ 13,255 ​ Fair value interest rate locks with customers ​ 4,024 ​ 4,024 ​ 557 ​ 557 ​ Financial Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Level 2 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deposits ​ 1,674,071 ​ 1,674,328 ​ 1,392,408 ​ 1,385,658 ​ Borrowings ​ 165,809 ​ 167,680 ​ 84,864 ​ 85,268 ​ Subordinated note ​ 10,000 ​ 11,083 ​ 9,885 ​ 10,599 ​ Accrued interest payable ​ 406 ​ 406 ​ 273 ​ 273 ​ Interest rate swaps ​ ​ 1,252 ​ ​ 1,252 ​ ​ — ​ ​ — ​ Forward TBA mortgage-backed securities ​ 1,602 ​ 1,602 ​ 8 ​ 8 ​ Level 3 inputs: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Mandatory and best effort forward commitments with investors ​ ​ 67 ​ ​ 67 ​ ​ 195 ​ ​ 195 ​
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation assumptions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Level 3 ​ Significant ​ Weighted Average Fair Value ​ Valuation ​ Unobservable ​ ​ ​ December 31, ​ ​ December 31, ​ Instruments Techniques Inputs Range 2020 ​ 2019 RECURRING ​ ​ ​ ​ Interest rate lock commitments with customers Quoted market prices Pull-through expectations 80% - 99% ​ 91.6 % ​ 94.5 % Individual forward sale commitments with investors Quoted market prices Pull-through expectations 80% - 99% ​ 91.6 % ​ 94.5 % Corporate securities ​ Discounted cash flows ​ Discount rate ​ 2.5% ​ 2.5 % ​ 2.1 % Municipal bonds ​ Discounted cash flows ​ Discount rate ​ 6.4% ​ 6.4 % ​ 3.4 % NONRECURRING ​ ​ ​ ​ ​ Impaired loans Fair value of underlying collateral Discount applied to the obtained appraisal 10.0% ​ 10.0 % ​ 10.0 % OREO ​ Fair value of collateral ​ Discount applied to the obtained appraisal ​ 10.0% ​ 10.0 % ​ 10.0 % Servicing rights ​ Industry sources ​ Pre-payment speeds ​ 0% - 50% ​ 32.6 % ​ 17.1 %

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, Numerator (in thousands): 2020 2019 Net income ​ $ 39,264 ​ $ 22,717 Dividends and undistributed earnings allocated to participating securities ​ ​ (192) ​ ​ (73) Net income available to common shareholders ​ $ 39,072 ​ $ 22,644 Denominator (shown as actual): ​ ​ ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 4,273,350 ​ 4,414,032 Dilutive shares ​ 81,019 ​ 108,992 Diluted weighted average common shares outstanding ​ 4,354,369 ​ 4,523,024 Basic earnings per share ​ $ 9.14 ​ $ 5.13 Diluted earnings per share ​ $ 8.97 ​ $ 5.01 Potentially dilutive weighted average share options that were not included in the computation of diluted earnings per share because to do so would be anti-dilutive ​ ​ 66,619 ​ ​ 36,337

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ Fair Value Cash flow hedges: Notional Asset Liability Interest rate swaps ​ $ 90,000 ​ $ 21 ​ $ 1,252 Non-hedging derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ Fallout adjusted interest rate lock commitments with customers ​ ​ 136,739 ​ ​ 4,024 ​ ​ — Mandatory and best effort forward commitments with investors ​ 25,027 ​ — ​ 67 Forward TBA mortgage-backed securities ​ 232,000 ​ — ​ 1,602 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ Fair Value Non-hedging derivatives: Notional Asset Liability Fallout adjusted interest rate lock commitments with customers ​ $ 33,914 ​ $ 557 ​ $ — Mandatory and best effort forward commitments with investors ​ 43,752 ​ — ​ 195 Forward TBA mortgage-backed securities ​ 46,000 ​ — ​ 8

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of changes in accumulated other comprehensive income (loss) by component, net of tax	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized Gains ​ ​ ​ ​ Gains and ​ and Losses ​ ​ ​ Losses on ​ on Available ​ ​ ​ ​ Cash Flow ​ for Sale ​ ​ Year Ended December 31, 2020 Hedges ​ Securities ​ Total Beginning balance ​ $ — ​ $ 788 ​ $ 788 Other comprehensive (loss) income before ​ ​ ​ ​ ​ ​ ​ ​ reclassification, net of tax ​ ​ (1,122) ​ ​ 2,947 ​ ​ 1,825 Amounts reclassified from accumulated other ​ ​ ​ ​ ​ ​ ​ ​ comprehensive income (loss), net of tax ​ ​ 155 ​ ​ (235) ​ ​ (80) Net current period other comprehensive (loss) income ​ (967) ​ ​ 2,712 ​ ​ 1,745 Ending balance ​ $ (967) ​ $ 3,500 ​ $ 2,533 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized Gains ​ ​ ​ ​ ​ Gains and ​ and Losses ​ ​ ​ ​ Losses on ​ on Available ​ ​ ​ ​ ​ Cash Flow ​ for Sale ​ ​ ​ Year Ended December 31, 2019 Hedges ​ Securities ​ Total Beginning balance ​ $ — ​ $ (1,479) ​ $ (1,479) Other comprehensive income before ​ ​ ​ ​ ​ ​ ​ ​ reclassification, net of tax ​ ​ — ​ ​ 2,292 ​ ​ 2,292 Amounts reclassified from accumulated other ​ ​ ​ ​ ​ ​ ​ ​ comprehensive loss, net of tax ​ ​ — ​ ​ (25) ​ ​ (25) Net current period other comprehensive income ​ — ​ ​ 2,267 ​ ​ 2,267 Ending balance ​ $ — ​ $ 788 ​ $ 788

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Awards	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ Year Ended December 31, ​ 2020 2019 Dividend yield ​ ​ 1.97% ​ ​ 1.23% Expected volatility, maximum ​ 26.79% ​ 18.90% Risk-free interest rate, maximum ​ 0.42% ​ 1.45% Expected term in years, maximum ​ 6.5 ​ 6.5 Weighted-average grant date fair value per option granted ​ $ 8.00 ​ $ 8.80 ​
Summary of Nonvested Awards	​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-Average ​ ​ ​ ​ Grant-Date Fair Value Nonvested Shares ​ Shares ​ Per Share Nonvested at January 1, 2020 40,215 ​ $ 53.64 Granted 24,880 ​ $ 42.70 Less vested 10,003 ​ $ 53.67 Forfeited or expired — ​ — Nonvested at December 31, 2020 55,092 ​ $ 48.70

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2020 Condensed income statement: Home Lending Commercial and Consumer Banking Total Net interest income (1) $ 5,123 ​ $ 68,997 $ 74,120 Provision for loan losses ​ (2,758) ​ (10,278) ​ (13,036) Noninterest income ​ 44,808 ​ 10,551 ​ 55,359 Noninterest expense ​ (17,351) ​ (49,242) ​ (66,593) Income before provision for income taxes ​ 29,822 ​ 20,028 ​ 49,850 Provision for income taxes ​ (6,333) ​ (4,253) ​ (10,586) Net income $ 23,489 ​ $ 15,775 $ 39,264 Total assets ​ $ 460,409 ​ $ 1,652,832 ​ $ 2,113,241 Total average assets for year ended $ 396,367 ​ $ 1,543,681 $ 1,940,048 FTEs ​ 152 ​ 354 ​ 506 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At or For the Year Ended December 31, 2019 Condensed income statement: Home Lending Commercial and Consumer Banking Total Net interest income (1) $ 6,307 ​ $ 64,001 $ 70,308 Provision for loan losses ​ (433) ​ (2,447) ​ (2,880) Noninterest income ​ 13,209 ​ 9,826 ​ 23,035 Noninterest expense ​ (14,283) ​ (48,050) ​ (62,333) Income before provision for income taxes ​ 4,800 ​ 23,330 ​ 28,130 Provision for income taxes ​ (924) ​ (4,489) ​ (5,413) Net income $ 3,876 ​ $ 18,841 $ 22,717 Total assets ​ $ 312,404 ​ $ 1,400,652 ​ $ 1,713,056 Total average assets for year ended $ 272,901 ​ $ 1,377,468 $ 1,650,369 FTEs ​ 127 ​ 325 ​ 452 ___________________________ (1) Net interest income is the difference between interest earned on assets and the cost of liabilities to fund those assets. Interest earned includes actual interest earned on segment assets and, if the segment has excess liabilities, interest credits for providing funding to the other segment. The cost of liabilities includes interest expense on segment liabilities and, if the segment does not have enough liabilities to fund its assets, a funding charge based on the cost of assigned liabilities to fund segment assets.

Revenue From Contracts With C_2

Revenue From Contracts With Customers (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Schedule of noninterest income, segregated by revenue streams in-scope and out-of-scope of Topic 606	​ ​ ​ ​ ​ ​ ​ ​ (Dollars in thousands): ​ At or For the Year Ended December 31, Noninterest income 2020 2019 In-scope of Topic 606: ​ ​ ​ ​ ​ ​ Debit card interchange fees ​ $ 1,879 ​ $ 1,848 Deposit service and account maintenance fees ​ ​ 786 ​ ​ 1,065 Noninterest income (in-scope of Topic 606) ​ ​ 2,665 ​ ​ 2,913 Noninterest income (out-of-scope of Topic 606) ​ ​ 52,694 ​ ​ 20,122 Total noninterest income ​ $ 55,359 ​ $ 23,035

Goodwill and other Intangible_2

Goodwill and other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in other intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other Intangible Assets ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ Gross CDI Amortization Net CDI Balance, December 31, 2018 ​ $ 7,490 ​ $ (1,273) ​ $ 6,217 Amortization ​ ​ — ​ ​ (760) ​ ​ (760) Balance, December 31, 2019 ​ ​ 7,490 ​ ​ (2,033) ​ ​ 5,457 Amortization ​ ​ — ​ ​ (706) ​ ​ (706) Balance, December 31, 2020 ​ $ 7,490 ​ $ (2,739) ​ $ 4,751
Schedule of Amortization Expense	​ ​ ​ ​ ​ 2021 $ 691 2022 ​ 691 2023 ​ 691 2024 ​ 621 2025 ​ ​ 525 Thereafter ​ 1,532 Total ​ $ 4,751

Parent Company Only Financial_2

Parent Company Only Financial Information (Tables)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Schedule of Condensed Balance Sheet	​ ​ ​ ​ ​ ​ ​ ​ Condensed Balance Sheets ​ December 31, Assets ​ 2020 ​ 2019 Cash and due from banks ​ $ 14,531 ​ $ 5,568 Investment in subsidiary ​ 225,484 ​ 204,570 Other assets ​ 202 ​ 172 Total assets ​ $ 240,217 ​ $ 210,310 Liabilities and Stockholders' Equity ​ ​ ​ Subordinated note, net ​ 10,000 ​ 9,885 Other liabilities ​ ​ 210 ​ 183 Total liabilities ​ 10,210 ​ 10,068 Stockholders' equity ​ 230,007 ​ 200,242 Total liabilities and stockholders' equity ​ $ 240,217 ​ $ 210,310
Schedule of Condensed Statements of Income	​ ​ ​ ​ ​ ​ ​ ​ Condensed Statements of Income ​ Year Ended December 31, ​ 2020 2019 Interest from subsidiary ​ $ — ​ $ 2 Interest expense on subordinated note ​ ​ (776) ​ ​ (679) Dividends received from subsidiary ​ ​ 20,862 ​ ​ 3,935 Other expenses ​ (195) ​ (142) Income before income tax benefit and equity in undistributed net income of subsidiary ​ 19,891 ​ 3,116 Income tax benefit ​ 204 ​ 172 Equity in undistributed earnings of subsidiary ​ ​ 19,169 ​ ​ 19,429 Net income ​ $ 39,264 ​ $ 22,717
Schedule of Condensed Statements of Cash Flows	​ ​ ​ ​ ​ ​ ​ ​ Condensed Statements of Cash Flows Year Ended December 31, ​ 2020 2019 Cash flows from operating activities: ​ ​ ​ ​ ​ ​ Net income ​ $ 39,264 ​ $ 22,717 Equity in undistributed net income of subsidiary ​ (19,169) ​ (19,429) Amortization ​ 115 ​ 20 ESOP compensation expense for allocated shares ​ 1,025 ​ 1,231 Share-based compensation expense related to stock options and restricted stock ​ 1,020 ​ 869 Other assets ​ (30) ​ 3 Other liabilities ​ 27 ​ 11 Net cash from operating activities ​ 22,252 ​ 5,422 Cash flows from investing activities: ​ ​ ​ Net proceeds from ESOP ​ 282 ​ 275 Net cash from investing activities ​ 282 ​ 275 Cash flows used by financing activities: ​ ​ ​ (Disbursements) proceeds from stock options exercised ​ (161) ​ 705 Common stock repurchased for employee/director taxes paid on restricted stock awards ​ ​ (34) ​ ​ (204) Common stock repurchased ​ (9,802) ​ (4,800) Dividends paid on common stock ​ ​ (3,574) ​ ​ (2,856) Net cash used by financing activities ​ (13,571) ​ (7,155) Net increase (decrease) in cash and cash equivalents ​ 8,963 ​ (1,458) Cash and cash equivalents, beginning of year ​ 5,568 ​ 7,026 Cash and cash equivalents, end of year ​ $ 14,531 ​ $ 5,568

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2020USD ($)itemsegmentOffice	Dec. 31, 2019USD ($)	Jan. 22, 2016item
Schedule of Accounting Policies [Line Items]
Number of operating segments | segment	2
Cash and due from banks and interest-bearing deposits in excess of FDIC insured limits	$ 17,000,000	$ 8,600,000
FHLB investment requirement, capital stock amount	$ 2,100,000
FHLB investment requirement, percent of advances from FHLB	4.00%
Federal Home Loan Bank Stock	$ 7,439,000	8,045,000
Impairment of FHLB stock	$ 0	0
Maximum term to qualify as cash and cash equivalents	90 days
Minimum term for accrual of interest on loans to be discontinued	90 days
Minimum term delinquent loan performs under contract terms and returned to accrual status	6 months
Federal Reserve Bank, Reserve Requirements, Cash and Federal Reserve Bank Deposits	$ 0	0
Marketing and advertising	530,000	678,000
Goodwill, Impairment Loss	$ 0	$ 0
Building and building improvements | Minimum
Schedule of Accounting Policies [Line Items]
Useful life	25 years
Building and building improvements | Maximum
Schedule of Accounting Policies [Line Items]
Useful life	40 years
Furniture, fixtures and equipment | Minimum
Schedule of Accounting Policies [Line Items]
Useful life	3 years
Furniture, fixtures and equipment | Maximum
Schedule of Accounting Policies [Line Items]
Useful life	10 years
Puget Sound [Member]
Schedule of Accounting Policies [Line Items]
Number of bank branches | item	21
Number of administrative offices that accept deposits | Office	1
Number of loan production offices | item	9
Tri-Cities, Washington [Member]
Schedule of Accounting Policies [Line Items]
Number of loan production offices | item	1
Anchor Bancorp
Schedule of Accounting Policies [Line Items]
Minimum term for accrual of interest on loans to be discontinued	90 days
Bank of America
Schedule of Accounting Policies [Line Items]
Number of bank branches | item			4
Commercial Real Estate | Covid 19 [Member]
Schedule of Accounting Policies [Line Items]
Loans restructured or modified	$ 31,200,000
COMMERCIAL BUSINESS LOANS. | Covid 19 [Member]
Schedule of Accounting Policies [Line Items]
Loans restructured or modified	12,800,000
One-to-four-family | Covid 19 [Member]
Schedule of Accounting Policies [Line Items]
Loans restructured or modified	308,000
CONSUMER LOANS. | Covid 19 [Member]
Schedule of Accounting Policies [Line Items]
Loans restructured or modified	$ 392,000

Investments - Available-for-sal

Investments - Available-for-sale securities reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
SECURITIES AVAILABLE-FOR-SALE
Amortized cost	$ 173,560	$ 125,053
Unrealized gains	5,639	1,347
Unrealized losses	(1,181)	(343)
Securities available-for-sale, at fair value	178,018	126,057
SECURITIES HELD-TO-MATURITY
Amortized cost	7,500	0
Unrealized gains	77
Unrealized losses	(21)
Securities held-to-maturity, at fair value	7,556
Total securities
Amortized cost	181,060
Unrealized gains	5,716
Unrealized losses	(1,202)
Total securities, at fair value	185,574	126,057
U.S. agency securities
SECURITIES AVAILABLE-FOR-SALE
Amortized cost	7,940	8,986
Unrealized gains	166	95
Unrealized losses	(1)	(15)
Securities available-for-sale, at fair value	8,105	9,066
Corporate securities
SECURITIES AVAILABLE-FOR-SALE
Amortized cost	11,885	10,525
Unrealized gains	54	52
Unrealized losses	(939)	(7)
Securities available-for-sale, at fair value	11,000	10,570
SECURITIES HELD-TO-MATURITY
Amortized cost	7,500
Unrealized gains	77
Unrealized losses	(21)
Securities held-to-maturity, at fair value	7,556
Municipal bonds
SECURITIES AVAILABLE-FOR-SALE
Amortized cost	69,572	20,516
Unrealized gains	2,435	604
Unrealized losses	(150)
Securities available-for-sale, at fair value	71,857	21,120
Mortgage-backed securities
SECURITIES AVAILABLE-FOR-SALE
Amortized cost	65,722	62,745
Unrealized gains	2,541	405
Unrealized losses	(76)	(300)
Securities available-for-sale, at fair value	68,187	62,850
U.S. Small Business Administration securities
SECURITIES AVAILABLE-FOR-SALE
Amortized cost	18,441	22,281
Unrealized gains	443	191
Unrealized losses	(15)	(21)
Securities available-for-sale, at fair value	$ 18,869	$ 22,451

Investments - Narrative (Detail

Investments - Narrative (Details)	12 Months Ended
	Dec. 31, 2020USD ($)securityitem	Dec. 31, 2019USD ($)item
Investments, Debt and Equity Securities [Abstract]
Investments with unrealized losses of less than one year | item	21	13
Investments with unrealized losses of more than one year | item	1	10
Number of securities pledged and held at FHLB	7	7
Pledged securities for FHLB	$ 8,800,000	$ 7,400,000
Public deposits	13,200,000	10,300,000
Collateral requirement	5,300,000	4,000,000
Other than temporary impairment losses, investments	$ 0	$ 0

Investments - Investments with

Investments - Investments with Unrealized Losses Policy (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value
Securities available-for-sale, Unrealized loss position, Fair Value, Less than 12 Months	$ 26,639	$ 21,710
Securities available-for-sale, Unrealized loss position, Fair Value, 12 Months or Longer	3,002	11,459
Securities available-for-sale, Unrealized loss position, Fair Value	29,641	33,169
Securities held-to-maturity, Unrealized loss position, Fair Value, Less than 12 Months	4,979
Securities held-to-maturity, Unrealized loss position, Fair Value	4,979
Total securities, Unrealized loss position, Fair Value, Less than 12 Months	31,618
Total securities, Unrealized loss position, Fair Value, 12 Months or Longer	3,002
Total securities, Unrealized loss position, Fair Value	34,620
Unrealized Losses
Securities available-for-sale, Unrealized loss position, Unrealized losses, Less than 12 Months	(1,170)	(197)
Securities available-for-sale, Unrealized loss position, Unrealized losses, 12 Months or Longer	(11)	(146)
Securities available-for-sale, Unrealized losses	(1,181)	(343)
Securities held-to-maturity, Unrealized loss position, Unrealized losses, Less than 12 Months	(21)
Securities held-to-maturity, Unrealized losses	(21)
Total securities, Unrealized loss position, Unrealized losses, Less than 12 Months	(1,191)
Total securities, Unrealized loss position, Unrealized losses, 12 Months or Longer	(11)
Total securities, Unrealized losses	(1,202)
U.S. agency securities
Fair Value
Securities available-for-sale, Unrealized loss position, Fair Value, Less than 12 Months	1,986	2,977
Securities available-for-sale, Unrealized loss position, Fair Value, 12 Months or Longer		0
Securities available-for-sale, Unrealized loss position, Fair Value	1,986	2,977
Unrealized Losses
Securities available-for-sale, Unrealized loss position, Unrealized losses, Less than 12 Months	(1)	(15)
Securities available-for-sale, Unrealized loss position, Unrealized losses, 12 Months or Longer		0
Securities available-for-sale, Unrealized losses	(1)	(15)
Corporate securities
Fair Value
Securities available-for-sale, Unrealized loss position, Fair Value, Less than 12 Months	7,059	1,993
Securities available-for-sale, Unrealized loss position, Fair Value	7,059	1,993
Securities held-to-maturity, Unrealized loss position, Fair Value, Less than 12 Months	4,979
Securities held-to-maturity, Unrealized loss position, Fair Value	4,979
Unrealized Losses
Securities available-for-sale, Unrealized loss position, Unrealized losses, Less than 12 Months	(939)	(7)
Securities available-for-sale, Unrealized losses	(939)	(7)
Securities held-to-maturity, Unrealized loss position, Unrealized losses, Less than 12 Months	(21)
Securities held-to-maturity, Unrealized losses	(21)
Municipal bonds
Fair Value
Securities available-for-sale, Unrealized loss position, Fair Value, Less than 12 Months	8,377
Securities available-for-sale, Unrealized loss position, Fair Value	8,377
Unrealized Losses
Securities available-for-sale, Unrealized loss position, Unrealized losses, Less than 12 Months	(150)
Securities available-for-sale, Unrealized losses	(150)
Mortgage-backed securities
Fair Value
Securities available-for-sale, Unrealized loss position, Fair Value, Less than 12 Months	6,903	12,345
Securities available-for-sale, Unrealized loss position, Fair Value, 12 Months or Longer	3,002	11,459
Securities available-for-sale, Unrealized loss position, Fair Value	9,905	23,804
Unrealized Losses
Securities available-for-sale, Unrealized loss position, Unrealized losses, Less than 12 Months	(65)	(154)
Securities available-for-sale, Unrealized loss position, Unrealized losses, 12 Months or Longer	(11)	(146)
Securities available-for-sale, Unrealized losses	(76)	(300)
U.S. Small Business Administration securities
Fair Value
Securities available-for-sale, Unrealized loss position, Fair Value, Less than 12 Months	2,314	4,395
Securities available-for-sale, Unrealized loss position, Fair Value	2,314	4,395
Unrealized Losses
Securities available-for-sale, Unrealized loss position, Unrealized losses, Less than 12 Months	(15)	(21)
Securities available-for-sale, Unrealized losses	$ (15)	$ (21)

Investments - Available for Sal

Investments - Available for Sale Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Amortized Cost
Securities available-for-sale, Total	$ 173,560	$ 125,053
Securities held-to-maturity, Total	7,500
Total securities	181,060	125,053
Fair Value
Securities available-for-sale, Total	178,018	126,057
Securities held-to-maturity, Total	7,556
Total securities	185,574	126,057
U.S. agency securities
Amortized Cost
Securities available-for-sale, Due after one year through five years	978	996
Securities available-for-sale, Due after five years through ten years	1,000	3,997
Securities available-for-sale, Due after ten years	5,962	3,993
Securities available-for-sale, Subtotal	7,940	8,986
Securities available-for-sale, Total	7,940	8,986
Fair Value
Securities available-for-sale, Due after one year through five years	1,060	1,036
Securities available-for-sale, Due after five years through ten years	1,036	4,027
Securities available-for-sale, Due after ten years	6,009	4,003
Securities available-for-sale, Subtotal	8,105	9,066
Securities available-for-sale, Total	8,105	9,066
Corporate securities
Amortized Cost
Securities available-for-sale, Due in one year or less	2,392	5,034
Securities available-for-sale, Due after one year through five years	3,493	3,491
Securities available-for-sale, Due after five years through ten years	4,000	2,000
Securities available-for-sale, Due after ten years	2,000
Securities available-for-sale, Subtotal	11,885	10,525
Securities available-for-sale, Total	11,885	10,525
Securities held-to-maturity, Due after five years through ten years	7,500
Fair Value
Securities available-for-sale, Due in one year or less	2,433	5,044
Securities available-for-sale, Due after one year through five years	3,491	3,532
Securities available-for-sale, Due after five years through ten years	3,676	1,994
Securities available-for-sale, Due after ten years	1,400
Securities available-for-sale, Subtotal	11,000	10,570
Securities available-for-sale, Total	11,000	10,570
Securities held-to-maturity, Due after five years through ten years	7,556
Municipal bonds
Amortized Cost
Securities available-for-sale, Due in one year or less	101
Securities available-for-sale, Due after one year through five years	3,749	3,774
Securities available-for-sale, Due after five years through ten years	7,994	3,162
Securities available-for-sale, Due after ten years	57,728	13,580
Securities available-for-sale, Subtotal	69,572	20,516
Securities available-for-sale, Total	69,572	20,516
Fair Value
Securities available-for-sale, Due in one year or less	101
Securities available-for-sale, Due after one year through five years	3,980	3,833
Securities available-for-sale, Due after five years through ten years	8,321	3,307
Securities available-for-sale, Due after ten years	59,455	13,980
Securities available-for-sale, Subtotal	71,857	21,120
Securities available-for-sale, Total	71,857	21,120
Mortgage-backed securities
Amortized Cost
Securities available-for-sale, Mortgage-backed securities	65,722	62,745
Securities available-for-sale, Total	65,722	62,745
Fair Value
Securities available-for-sale, Mortgage-backed securities	68,187	62,850
Securities available-for-sale, Total	68,187	62,850
Federal National Mortgage Association ("FNMA")
Amortized Cost
Securities available-for-sale, Mortgage-backed securities	47,675	42,131
Fair Value
Securities available-for-sale, Mortgage-backed securities	50,005	42,333
Federal Home Loan Mortgage Corporation ("FHLMC")
Amortized Cost
Securities available-for-sale, Mortgage-backed securities	11,825	15,250
Fair Value
Securities available-for-sale, Mortgage-backed securities	11,913	15,179
Government National Mortgage Association ("GNMA")
Amortized Cost
Securities available-for-sale, Mortgage-backed securities	6,222	5,364
Fair Value
Securities available-for-sale, Mortgage-backed securities	6,269	5,338
U.S. Small Business Administration securities
Amortized Cost
Securities available-for-sale, Due after one year through five years	2,266	1,546
Securities available-for-sale, Due after five years through ten years	8,097	11,500
Securities available-for-sale, Due after ten years	8,078	9,235
Securities available-for-sale, Subtotal	18,441	22,281
Securities available-for-sale, Total	18,441	22,281
Fair Value
Securities available-for-sale, Due after one year through five years	2,353	1,555
Securities available-for-sale, Due after five years through ten years	8,333	11,598
Securities available-for-sale, Due after ten years	8,183	9,298
Securities available-for-sale, Subtotal	18,869	22,451
Securities available-for-sale, Total	$ 18,869	$ 22,451

Investments - Gains and Losses

Investments - Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Proceeds	$ 12,214	$ 10,554
Gross Gains	$ 300	91
Gross Losses		$ (59)

Loans Receivable and Allowanc_3

Loans Receivable and Allowance For Loan Losses - Composition of Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	$ 1,574,227	$ 1,351,893
Allowance for loan losses	(26,172)	(13,229)
Deferred costs and fees, net	(4,017)	(3,273)
Premiums on purchased loans, net	943	955
Total loans receivable, net	1,544,981	1,336,346
REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	925,481	824,040
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	222,719	210,749
Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	216,975	179,654
Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	43,093	38,167
One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	311,093	261,539
Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	131,601	133,931
CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	375,178	326,210
Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	286,020	254,691
Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	85,740	67,179
Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	3,418	4,340
COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	273,568	201,643
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	224,476	140,531
Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable, gross	$ 49,092	$ 61,112

Loans Receivable and Allowanc_4

Loans Receivable and Allowance For Loan Losses - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)divisionsegment	Dec. 31, 2019USD ($)segmentdivision
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan portfolio segments | segment	3	3
Number of warehouse lending divisions | division	2	2
Loans that qualify as collateral for FHLB advances	$ 774,800	$ 646,100
Loans that qualify as collateral for Federal Reserve Bank lines of credit	369,200	318,800
Total loans receivable, gross	$ 1,574,227	1,351,893
Minimum term for accrual of interest on loans to be discontinued	90 days
Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 131,601	133,931
COMMERCIAL BUSINESS LOANS.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	273,568	201,643
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	224,476	140,531
Small Business Administration (SBA) Cares Act Payment Protection Program [Member] | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	62,100
Anchor Bancorp
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining net discount on loans acquired	1,500	2,700
Total loans receivable, gross	$ 132,600	$ 198,500
Minimum term for accrual of interest on loans to be discontinued	90 days

Loans Receivable and Allowanc_5

Loans Receivable and Allowance For Loan Losses - Allowance for Loan Losses by Loan Categories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
ALLOWANCE FOR LOAN LOSSES
Beginning balance	$ 13,229	$ 12,349
Provision for loan losses	13,036	2,880
Charge-offs	(1,123)	(2,628)
Recoveries	1,030	628
Net recoveries (charge-offs)	(93)	(2,000)
Ending balance	26,172	13,229
Period End Amount Allocated to
Loans individually evaluated for impairment	1,310	182
Loans collectively evaluated for impairment	24,862	13,047
Ending balance	26,172	13,229
LOANS RECEIVABLE
Loans individually evaluated for impairment	7,761	3,128
Loans collectively evaluated for impairment	1,566,466	1,348,765
Total loans receivable	1,574,227	1,351,893
REAL ESTATE LOANS.
ALLOWANCE FOR LOAN LOSSES
Beginning balance	6,206	5,761
Provision for loan losses	7,622	439
Charge-offs		(5)
Recoveries	18	11
Net recoveries (charge-offs)	18	6
Ending balance	13,846	6,206
Period End Amount Allocated to
Loans individually evaluated for impairment	15	15
Loans collectively evaluated for impairment	13,831	6,191
Ending balance	13,846	6,206
LOANS RECEIVABLE
Loans individually evaluated for impairment	1,280	2,635
Loans collectively evaluated for impairment	924,201	821,405
Total loans receivable	925,481	824,040
CONSUMER LOANS.
ALLOWANCE FOR LOAN LOSSES
Beginning balance	3,766	3,351
Provision for loan losses	3,372	838
Charge-offs	(1,101)	(1,040)
Recoveries	659	617
Net recoveries (charge-offs)	(442)	(423)
Ending balance	6,696	3,766
Period End Amount Allocated to
Loans individually evaluated for impairment	305	167
Loans collectively evaluated for impairment	6,391	3,599
Ending balance	6,696	3,766
LOANS RECEIVABLE
Loans individually evaluated for impairment	871	493
Loans collectively evaluated for impairment	374,307	325,717
Total loans receivable	375,178	326,210
COMMERCIAL BUSINESS LOANS.
ALLOWANCE FOR LOAN LOSSES
Beginning balance	3,254	3,191
Provision for loan losses	1,354	1,646
Charge-offs	(22)	(1,583)
Recoveries	353
Net recoveries (charge-offs)	331	(1,583)
Ending balance	4,939	3,254
Period End Amount Allocated to
Loans individually evaluated for impairment	990
Loans collectively evaluated for impairment	3,949	3,254
Ending balance	4,939	3,254
LOANS RECEIVABLE
Loans individually evaluated for impairment	5,610
Loans collectively evaluated for impairment	267,958	201,643
Total loans receivable	273,568	201,643
Unallocated Financing Receivables [Member]
ALLOWANCE FOR LOAN LOSSES
Beginning balance	3	46
Provision for loan losses	688	(43)
Ending balance	691	3
Period End Amount Allocated to
Loans collectively evaluated for impairment	691	3
Ending balance	$ 691	$ 3

Loans Receivable and Allowanc_6

Loans Receivable and Allowance For Loan Losses - Aging Analysis of Past Due Loans) (Details)	12 Months Ended
	Dec. 31, 2020USD ($)loan	Dec. 31, 2019USD ($)loan
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 6,403,000	$ 4,159,000
Current	1,567,824,000	1,347,734,000
Total loans receivable	$ 1,574,227,000	$ 1,351,893,000
Number of TDR loans	0	0
REAL ESTATE LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans receivable	$ 925,481,000	$ 824,040,000
Total real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,638,000	2,985,000
Current	921,843,000	821,055,000
Total loans receivable	925,481,000	824,040,000
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Current	222,719,000	210,749,000
Total loans receivable	222,719,000	210,749,000
Construction and development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,850,000	533,000
Current	215,125,000	179,121,000
Total loans receivable	216,975,000	179,654,000
Home equity.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	483,000	294,000
Current	42,610,000	37,873,000
Total loans receivable	43,093,000	38,167,000
One-to-four-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,305,000	2,158,000
Current	309,788,000	259,381,000
Total loans receivable	311,093,000	261,539,000
Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Current	131,601,000	133,931,000
Total loans receivable	131,601,000	133,931,000
CONSUMER LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,561,000	1,174,000
Current	373,617,000	325,036,000
Total loans receivable	375,178,000	326,210,000
Indirect home improvement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,339,000	1,066,000
Current	284,681,000	253,625,000
Total loans receivable	286,020,000	254,691,000
Marine
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	127,000	15,000
Current	85,613,000	67,164,000
Total loans receivable	85,740,000	67,179,000
Other consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	95,000	93,000
Current	3,323,000	4,247,000
Total loans receivable	3,418,000	4,340,000
COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,204,000	0
Current	272,364,000	201,643,000
Total loans receivable	273,568,000	201,643,000
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,204,000	0
Current	223,272,000	140,531,000
Total loans receivable	224,476,000	140,531,000
Warehouse lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Current	49,092,000	61,112,000
Total loans receivable	49,092,000	61,112,000
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,150,000	2,314,000
30-59 Days Past Due | Total real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,366,000	1,536,000
30-59 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
30-59 Days Past Due | Construction and development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,850,000	533,000
30-59 Days Past Due | Home equity.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	127,000	109,000
30-59 Days Past Due | One-to-four-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	389,000	894,000
30-59 Days Past Due | Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
30-59 Days Past Due | CONSUMER LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	784,000	778,000
30-59 Days Past Due | Indirect home improvement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	683,000	692,000
30-59 Days Past Due | Marine
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	28,000	15,000
30-59 Days Past Due | Other consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	73,000	71,000
30-59 Days Past Due | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
30-59 Days Past Due | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
30-59 Days Past Due | Warehouse lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,175,000	343,000
60-89 Days Past Due | Total real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	541,000	114,000
60-89 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
60-89 Days Past Due | Construction and development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
60-89 Days Past Due | Home equity.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	137,000	0
60-89 Days Past Due | One-to-four-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	404,000	114,000
60-89 Days Past Due | Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
60-89 Days Past Due | CONSUMER LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	430,000	229,000
60-89 Days Past Due | Indirect home improvement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	331,000	227,000
60-89 Days Past Due | Marine
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	77,000	0
60-89 Days Past Due | Other consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	22,000	2,000
60-89 Days Past Due | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,204,000	0
60-89 Days Past Due | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,204,000	0
60-89 Days Past Due | Warehouse lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,078,000	$ 1,502,000
Number Of Loans Accruing Interest | loan	0	0
90 Days or More Past Due | Total real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 731,000	$ 1,335,000
90 Days or More Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
90 Days or More Past Due | Construction and development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
90 Days or More Past Due | Home equity.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	219,000	185,000
90 Days or More Past Due | One-to-four-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	512,000	1,150,000
90 Days or More Past Due | Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
90 Days or More Past Due | CONSUMER LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	347,000	167,000
90 Days or More Past Due | Indirect home improvement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	325,000	147,000
90 Days or More Past Due | Marine
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	22,000	0
90 Days or More Past Due | Other consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		20,000
90 Days or More Past Due | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
90 Days or More Past Due | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
90 Days or More Past Due | Warehouse lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Non-Accrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	7,761,000	3,033,000
Non-Accrual | Total real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	1,280,000	2,540,000
Non-Accrual | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	0	1,086,000
Non-Accrual | Construction and development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	0	0
Non-Accrual | Home equity.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	636,000	190,000
Non-Accrual | One-to-four-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	644,000	1,264,000
Non-Accrual | Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	0	0
Non-Accrual | CONSUMER LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	871,000	493,000
Non-Accrual | Indirect home improvement
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	826,000	468,000
Non-Accrual | Marine
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	44,000	0
Non-Accrual | Other consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	1,000	25,000
Non-Accrual | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	5,610,000	0
Non-Accrual | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	5,610,000	0
Non-Accrual | Warehouse lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual	0	$ 0
Covid 19 [Member] | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans restructured or modified	31,200,000
Covid 19 [Member] | One-to-four-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans restructured or modified	308,000
Covid 19 [Member] | CONSUMER LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans restructured or modified	392,000
Covid 19 [Member] | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans restructured or modified	$ 12,800,000
Number of loans classified as current and non-accruing and not classified as TDRs | loan	2
Amount of loans current and non accruing and not classified as TDRs	$ 4,400,000

Loans Receivable and Allowanc_7

Loans Receivable and Allowance For Loan Losses - Financing Receivables, Related Allowance Recorded and No Related Allowance Recorded (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with no related allowance recorded	$ 2,535	$ 2,685
Unpaid Principal Balance, with an allowance recorded	5,339	537
Impaired Financing Receivable, Unpaid Principal Balance, Total	7,874	3,222
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with no related allowance recorded	2,423	2,592
Recorded Investment, with an allowance recorded	5,338	536
Recorded Investment	7,761	3,128
Impaired Financing Receivable Related Allowance Abstract
Related Allowance, with an allowance recorded	1,310	182
Related Allowance	1,310	182
Commercial Real Estate
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with no related allowance recorded		1,097
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with no related allowance recorded		1,086
Home equity.
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with no related allowance recorded	687	278
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with no related allowance recorded	636	225
Impaired Financing Receivable Related Allowance Abstract
Related Allowance, with no related allowance recorded		0
One-to-four-family
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with no related allowance recorded	645	1,293
Unpaid Principal Balance, with an allowance recorded	61	61
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with no related allowance recorded	584	1,264
Recorded Investment, with an allowance recorded	60	60
Impaired Financing Receivable Related Allowance Abstract
Related Allowance, with no related allowance recorded	0
Related Allowance, with an allowance recorded	15	15
Indirect home improvement
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with an allowance recorded	826	468
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with an allowance recorded	826	468
Impaired Financing Receivable Related Allowance Abstract
Related Allowance, with an allowance recorded	289	164
Marine
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with an allowance recorded	44
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with an allowance recorded	44
Impaired Financing Receivable Related Allowance Abstract
Related Allowance, with an allowance recorded	15
Other consumer loans
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with no related allowance recorded		17
Unpaid Principal Balance, with an allowance recorded	1	8
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with no related allowance recorded		17
Recorded Investment, with an allowance recorded	1	8
Impaired Financing Receivable Related Allowance Abstract
Related Allowance, with an allowance recorded	1
Related Allowance		$ 3
Commercial and industrial
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid Principal Balance, with no related allowance recorded	1,203
Unpaid Principal Balance, with an allowance recorded	4,407
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment, with no related allowance recorded	1,203
Recorded Investment, with an allowance recorded	4,407
Impaired Financing Receivable Related Allowance Abstract
Related Allowance, with an allowance recorded	$ 990

Loans Receivable and Allowanc_8

Loans Receivable and Allowance For Loan Losses - Average Recorded Investment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with no related allowance recorded	$ 2,538	$ 1,980
Average Recorded Investment, with an allowance recorded	3,307	582
Impaired Financing Receivable, Average Recorded Investment	5,845	2,562
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with no related allowance recorded	79	95
Interest Income Recognized, with an allowance recorded	225	48
Interest Income Recognized	304	143
Commercial Real Estate
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with no related allowance recorded	996	90
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with no related allowance recorded		56
Home equity.
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with no related allowance recorded	485	206
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with no related allowance recorded	25	3
One-to-four-family
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with no related allowance recorded	954	1,500
Average Recorded Investment, with an allowance recorded	60	5
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with no related allowance recorded	17	34
Interest Income Recognized, with an allowance recorded		5
Indirect home improvement
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with an allowance recorded	675	463
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with an allowance recorded	60	42
Marine
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with an allowance recorded	40	13
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with an allowance recorded	3
Other consumer loans
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with no related allowance recorded	3	4
Average Recorded Investment, with an allowance recorded	1	5
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with no related allowance recorded		2
Interest Income Recognized, with an allowance recorded		1
Commercial and industrial
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average Recorded Investment, with no related allowance recorded	100	180
Average Recorded Investment, with an allowance recorded	2,531	$ 96
Impaired Financing Receivable, Interest Income [Abstract]
Interest Income Recognized, with no related allowance recorded	37
Interest Income Recognized, with an allowance recorded	$ 162

Loans Receivable and Allowanc_9

Loans Receivable and Allowance For Loan Losses - Loans by Credit Quality Indicator (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)loan	Dec. 31, 2019USD ($)
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1,574,227	$ 1,351,893
Number of reported TDR loan modified previous 12 months and subsequently defaulted | loan	0
REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 925,481	824,040
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	222,719	210,749
Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	216,975	179,654
Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans	43,093	38,167
One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	311,093	261,539
Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	131,601	133,931
CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	375,178	326,210
Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans	286,020	254,691
Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans	85,740	67,179
Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,418	4,340
COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	273,568	201,643
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	224,476	140,531
Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans	49,092	61,112
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,461,600	1,317,980
Pass | REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	847,809	806,126
Pass | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	157,932	203,703
Pass | Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	212,209	177,109
Pass | Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans	42,457	37,942
Pass | One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	303,610	259,580
Pass | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	131,601	127,792
Pass | CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	374,307	325,717
Pass | Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans	285,194	254,223
Pass | Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans	85,696	67,179
Pass | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,417	4,315
Pass | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	239,484	186,137
Pass | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	190,392	125,025
Pass | Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans	49,092	61,112
Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	87,858	22,028
Watch | REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	63,913	11,593
Watch | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	60,834	2,274
Watch | Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,917	2,545
Watch | Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Watch | One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	162	635
Watch | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	6,139
Watch | CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Watch | Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Watch | Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Watch | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Watch | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,945	10,435
Watch | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,945	10,435
Watch | Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,122	5,223
Special Mention | REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,049	3,781
Special Mention | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,013	3,686
Special Mention | Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,849	0
Special Mention | Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	35
Special Mention | One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	187	60
Special Mention | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Special Mention | CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Special Mention | Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Special Mention | Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Special Mention | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Special Mention | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,073	1,442
Special Mention | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,073	1,442
Special Mention | Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,647	6,662
Substandard | REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,710	2,540
Substandard | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	940	1,086
Substandard | Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Substandard | Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans	636	190
Substandard | One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,134	1,264
Substandard | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Substandard | CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	871	493
Substandard | Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans	826	468
Substandard | Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans	44	0
Substandard | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	1	25
Substandard | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,066	3,629
Substandard | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,066	3,629
Substandard | Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Doubtful | Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | REAL ESTATE LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Construction and development
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Home equity.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | One-to-four-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | CONSUMER LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Indirect home improvement
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Marine
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Other consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | COMMERCIAL BUSINESS LOANS.
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loss | Warehouse lending
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 0	$ 0

Loans Receivable and Allowan_10

Loans Receivable and Allowance For Loan Losses - Related Party Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable, Related Parties [Roll Forward]
Beginning balance	$ 3,249	$ 3,325
Additions	581
Repayments	(33)	(76)
Ending balance	3,797	3,249
Aggregate loan balances of extended credit	$ 4,200	$ 3,600

Servicing Rights - Narrative (D

Servicing Rights - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractually specified servicing fees, late fees, and other ancillary fees	$ 4.4	$ 3.5
Mortgage servicing rights
Off-balance Sheet Risks, Disclosure Information [Line Items]
The unpaid principal balances of mortgage loans serviced	2,170	1,460
Fair market value of servicing rights' assets	$ 12.8	$ 13.3

Servicing Rights - Servicing Ri

Servicing Rights - Servicing Rights (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 11,560	$ 10,429
Additions	11,139	5,400
Servicing rights amortized	(8,135)	(4,177)
Impairment on servicing rights	(1,969)	(92)
Ending balance	$ 12,595	$ 11,560

Servicing Rights - Valuation As

Servicing Rights - Valuation Assumptions (Details) - Mortgage servicing rights	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Off-balance Sheet Risks, Disclosure Information [Line Items]
Weighted average discount rate	9.10%	9.70%
Conditional prepayment rate ("CPR")	32.60%	17.10%
Weighted average life in years	3 years	5 years 1 month 6 days

Servicing Rights - Changes in V

Servicing Rights - Changes in Valuation Assumptions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Off-balance Sheet Risks, Disclosure Information [Line Items]
Basis Points Drop in Note Rate, Assumption One	0.50%	0.50%
Basis Points Drop in Note Rate, Assumption Two	1.00%	1.00%
Mortgage servicing rights
Off-balance Sheet Risks, Disclosure Information [Line Items]
Aggregate portfolio principal balance	$ 2,133,473	$ 1,463,732
Weighted average rate of note	3.50%	4.20%
Conditional prepayment rate	32.60%	17.10%
Conditional prepayment rate, 0.5% Adverse Change	40.60%	24.60%
Conditional prepayment rate, 1.0% Adverse Change	59.60%	32.50%
Fair value MSR	$ 12,833	$ 13,255
Fair value MSR, 0.5% Adverse Change	10,922	10,582
Fair value of MSR, 1.0% Adverse Change	$ 8,286	$ 8,674
Percentage of MSR	0.60%	0.90%
Percentage of MSR, 0.5% Adverse Change	0.50%	0.70%
Percentage of MSR, 1.0% Adverse Change	0.40%	0.60%
Discount rate	9.10%	9.70%
Discount rate, 0.5% Adverse Change	9.60%	10.20%
Discount rate, 1.0% Adverse Change	10.10%	10.70%
Fair value MSR, 0.5% Adverse Change	$ 12,696	$ 13,037
Fair value MSR, 1.0% Adverse Change	$ 12,562	$ 12,826
Percentage of MSR, 0.5% Adverse Change	0.60%	0.90%
Percentage of MSR, 1.0% Adverse Change	0.60%	0.90%

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 46,764	$ 45,385
Less accumulated depreciation and amortization	(19,421)	(16,615)
Property, Plant and Equipment, Net, Total	27,343	28,770
Depreciation and amortization	2,800	2,800
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	5,227	5,227
Buildings
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	16,769	16,769
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	14,724	13,562
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	2,859	2,848
Building improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	6,830	6,572
Projects in process
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 355	$ 407

Leases (Details)

Leases (Details)	12 Months Ended
	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Options to extend	true
Renewal term	5 years
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	5 months
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	9 years 6 months

Leases - Components of lease co

Leases - Components of lease cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease cost:
Operating lease cost	$ 1,393	$ 1,285
Short-term lease cost	11	166
Total lease cost	1,404	1,451
Operating cash flows from operating leases	$ 1,365	$ 1,331
Weighted average remaining lease term- operating leases	5 years 4 months 24 days	5 years 3 months 18 days
Weighted average discount rate- operating leases	2.48%	3.00%

Leases - Maturities of operatin

Leases - Maturities of operating lease liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Maturities of operating lease liabilities
2021	$ 1,319
2022	1,222
2023	839
2024	787
2025	478
Thereafter	949
Total lease payments	5,594
Less imputed interest	(418)
Operating lease liabilities	$ 5,176	$ 5,214

Other Real Estate Owned - Activ

Other Real Estate Owned - Activity related to OREO (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other Real Estate [Roll Forward]
Beginning balance	$ 168	$ 689
Additions	0	242
Gross proceeds from sale of OREO	(76)	(901)
(Loss) gain on sale of OREO	(2)	138
Ending balance	$ 90	$ 168

Other Real Estate Owned - Narra

Other Real Estate Owned - Narrative (Details)	12 Months Ended
	Dec. 31, 2020USD ($)property	Dec. 31, 2019USD ($)property
Banking and Thrift [Abstract]
OREO properties	$ 90,000	$ 168,000
Number of OREO Properties | property	1	2
Holding costs	$ 4,000	$ 13,000
Mortgage loans in process of foreclosure	$ 662,000	$ 1,000,000

Deposits - Deposit Liabilities

Deposits - Deposit Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Banking and Thrift [Abstract]
Noninterest-bearing checking	$ 348,421	$ 260,131
Interest-bearing checking	226,282	177,972
Savings	152,842	118,845
Money market	429,548	270,489
Certificates of deposit less than $100,000	299,157	277,988
Certificates of deposit of $100,000 through $250,000	135,901	181,402
Certificates of deposit of $250,000 and over	67,488	92,110
Escrow accounts related to mortgages serviced	14,432	13,471
Total deposits	1,674,071	1,392,408
Related-party deposits	4,000	3,300
Cash on hand and deposit balances with FRB	$ 0	$ 0

Deposits - Maturities of Time D

Deposits - Maturities of Time Deposits for Future Periods (Details) $ in Thousands	Dec. 31, 2020USD ($)
Banking and Thrift [Abstract]
Maturing in 2021	$ 340,867
Maturing in 2022	88,529
Maturing in 2023	19,991
Maturing in 2024	20,131
Maturing in 2025	33,027
Thereafter	1
Total	$ 502,546

Deposits - Interest Expense by

Deposits - Interest Expense by Deposit Category (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Banking and Thrift [Abstract]
Interest-bearing checking	$ 388	$ 1,414
Savings and money market	2,458	3,098
Certificates of deposit	9,134	11,650
Total	$ 11,980	$ 16,162

Debt - Narrative (Details)

Debt - Narrative (Details) $ in Thousands	Feb. 10, 2021USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2020USD ($)loan	Dec. 31, 2019USD ($)	Oct. 15, 2015USD ($)
Debt Instrument [Line Items]
Federal home loan bank, advances, general debt obligations, maximum amount available, percentage of total assets (as a percent)			45.00%
Federal home loan bank, advances, general debt obligations, collateral pledged			$ 774,800
Federal home loan bank, borrowing capacity			568,200
Federal home loan bank, unused borrowing capacity			459,900
Unsecured Fed Funds lines of credit			101,000
Unsecured Fed Funds, lines of credit, outstanding balance			0
Total loans receivable, gross			1,574,227	$ 1,351,893
Commercial and industrial
Debt Instrument [Line Items]
Total loans receivable, gross			224,476	140,531
Fixed To Floating Rate Subordinated Note Due 2031 | Private Placement
Debt Instrument [Line Items]
Private placement amount	$ 50,000
Annual interest rate (as a percent)	3.75%
Offering price percentage (as a percent)	100.00%
Net proceeds	$ 49,300
Subordinated Note
Debt Instrument [Line Items]
Principal amount of subordinated debt					$ 10,000
Annual interest rate (as a percent)					6.50%
Contributions of proceeds from subordinated debt		$ 9,000
Federal Reserve Bank
Debt Instrument [Line Items]
Warehouse lines of credit			179,600	156,100
Line of credit, outstanding balance			0	0
Federal Reserve Bank
Debt Instrument [Line Items]
Loans pledged as collateral			369,200	$ 318,800
Small Business Administration (SBA) Cares Act Payment Protection Program [Member]
Debt Instrument [Line Items]
Additional unused borrowing capacity			$ 0
Number of loans funded | loan			423
Small Business Administration (SBA) Cares Act Payment Protection Program [Member] | Commercial and industrial
Debt Instrument [Line Items]
Total loans receivable, gross			$ 62,100
Small Business Administration SBA Cares Act Paycheck Protection Program Liquidity Facility [Member]
Debt Instrument [Line Items]
Annual interest rate (as a percent)			0.35%
Borrowings			$ 63,300
Maturing in 2022			62,000
Maturing in 2025			$ 1,300

Debt - Advances on Borrowing Li

Debt - Advances on Borrowing Line (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank and PPP Borrowings [Line Items]
Federal home loan bank, advances, general debt obligations	$ 102,528
Long-term Debt	165,809	$ 84,864
Paycheck Protection Program Liquidity Facility
Federal Home Loan Bank and PPP Borrowings [Line Items]
Long-term Debt	$ 63,281
Debt Instrument, Interest Rate, Stated Percentage	0.35%
Maximum | Paycheck Protection Program Liquidity Facility
Federal Home Loan Bank and PPP Borrowings [Line Items]
Long-term Debt	$ 74,112	0
Securities Line
Federal Home Loan Bank and PPP Borrowings [Line Items]
Federal home loan bank, advances, general debt obligations	$ 102,528	$ 84,864
Securities Line | Minimum
Federal Home Loan Bank and PPP Borrowings [Line Items]
Federal Home Loan Bank, interest rates	1.58%	1.58%
Securities Line | Maximum
Federal Home Loan Bank and PPP Borrowings [Line Items]
Federal Home Loan Bank, interest rates	2.87%	2.87%

Debt - Maximum and Average bala

Debt - Maximum and Average balances, Weighted Average Interest Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Maximum balance:
Federal Home Loan Bank advances and Fed Funds	$ 159,114	$ 186,401
Federal Reserve Bank	40,000	5,000
Fed funds line of credit	865	5,000
Long-term Debt	165,809	84,864
Average balance:
Federal Home Loan Bank advances and Fed Funds	99,773	93,653
Federal Reserve Bank	1,096	167
Fed Funds lines of credit	$ 3	$ 318
Weighted average interest rates
Federal Home Loan Bank advances and Fed Funds (as a percent)	1.80%	2.61%
Fed Funds (as a percent)	0.25%	2.96%
Fed Funds lines of credit (as a percent)	0.36%	2.09%
Subordinated note
Average balance:
Long term debt	$ 10,000	$ 10,000
Weighted average interest rates
Weighted average interest rate (as a percent)	6.50%	6.50%
Subordinated note | Maximum
Maximum balance:
Long-term Debt	$ 10,000	$ 10,000
Paycheck Protection Program Liquidity Facility
Maximum balance:
Long-term Debt	63,281
Average balance:
Long term debt	$ 46,965	$ 0
Weighted average interest rates
Weighted average interest rate (as a percent)	0.35%	0.00%
Paycheck Protection Program Liquidity Facility | Maximum
Maximum balance:
Long-term Debt	$ 74,112	$ 0

Debt - Schedule of Federal Home

Debt - Schedule of Federal Home Loan Bank Advances Maturities Summary Due (Details) $ in Thousands	Dec. 31, 2020USD ($)
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
2021	$ 75,000
2022	13,633
2023	13,895
Total	$ 102,528
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due [Abstract]
2021, Interest Rates (percent)	1.60%
2022, Interest Rates (percent)	2.03%
2023, Interest Rates (percent)	1.77%

Employee Benefits - Narrative (

Employee Benefits - Narrative (Details) - USD ($)	Jul. 09, 2012	Jan. 02, 2012	Dec. 31, 2020	Dec. 31, 2019
Compensation and Retirement Disclosure [Abstract]
Number of hours of service required for participation in ESOP, per first 12 month period (in hours)		1000 hours
Vesting percentage after requisite service period is met (as a percent)		100.00%
Requisite service period (in years)		2 years
Number of hours per service period year (in hours)		1000 hours
ESOP borrowings from FS Bancorp	$ 2,600,000
Shares acquired (in shares)	259,210		239,665	241,353
Employee stock ownership plan (ESOP), weighted average purchase price of shares purchased (in dollars per share)	$ 10.17
Amortization period of ESOP loan	10 years
Employee stock ownership plan (ESOP), debt structure, employer loan, interest rate	2.30%
Employee stock ownership plan (ESOP), periodic installment payments from esop, amount paid			$ 282,000
Employee stock ownership plan (ESOP), interest payments from esop			13,000
ESOP compensation expense for allocated shares			$ 1,307,000	$ 1,506,000

Employee Benefits - Schedule of

Employee Benefits - Schedule of Shares Under ESOP (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jul. 09, 2012
Employee Stock Ownership Plan (ESOP), Shares in ESOP [Abstract]
Allocated shares	213,744	189,511
Committed to be released shares	0	0
Unallocated shares	25,921	51,842
Total ESOP shares (in shares)	239,665	241,353	259,210
Fair value of unallocated shares (in thousands)	$ 1,307	$ 3,006

Employee Benefits - 401(K) Plan

Employee Benefits - 401(K) Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Schedule of Defined Contribution Plans Disclosures [Line Items]
Defined contribution plan, minimum age requirement	18 years
Percentage vested in deferral contributions account	100.00%
Employer contributions	$ 1.5	$ 1.2
Contributions between 1% to 3%
Schedule of Defined Contribution Plans Disclosures [Line Items]
Employer matching percentage	100.00%
Contributions between 1% to 3% | Minimum
Schedule of Defined Contribution Plans Disclosures [Line Items]
Defined contribution plan, employee contribution (percent)	1.00%
Contributions between 1% to 3% | Maximum
Schedule of Defined Contribution Plans Disclosures [Line Items]
Defined contribution plan, employee contribution (percent)	3.00%
Contributions between 4% and 5%
Schedule of Defined Contribution Plans Disclosures [Line Items]
Employer matching percentage	50.00%
Contributions between 4% and 5% | Minimum
Schedule of Defined Contribution Plans Disclosures [Line Items]
Defined contribution plan, employee contribution (percent)	4.00%
Contributions between 4% and 5% | Maximum
Schedule of Defined Contribution Plans Disclosures [Line Items]
Defined contribution plan, employee contribution (percent)	5.00%

Income Taxes - Components of In

Income Taxes - Components of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Provision for income taxes
Current	$ 12,976	$ 4,425
Deferred	(2,390)	988
Income Tax Expense (Benefit), Total	$ 10,586	$ 5,413

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income tax provision at statutory rate	$ 10,469	$ 5,907
Tax exempt income	(292)	(225)
Nondeductible items resulting in increase in tax	57	129
Increase (decrease) in tax resulting from other items	175	(78)
Equity compensation	(46)	(691)
Executive compensation	8	112
ESOP	215	259
Income Tax Expense (Benefit), Total	$ 10,586	$ 5,413
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Income tax provision at statutory rate	21.00%	21.00%
Tax exempt income	(0.60%)	(0.80%)
Nondeductible items resulting in increase in tax	0.10%	0.50%
Increase (decrease) in tax resulting from other items	0.40%	(0.30%)
Equity compensation	(0.10%)	(2.50%)
Executive compensation	0.00%	0.40%
ESOP	0.40%	0.90%
Total	21.20%	19.20%

Income Taxes - Deferred Assets

Income Taxes - Deferred Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets
Net operating loss carryforward	$ 527	$ 864
Allowance for loan losses	5,775	2,844
Purchase accounting adjustments	0	466
Other real estate owned	126	126
Non-accrued loan interest	6	13
Restricted stock awards	97	68
Non-qualified stock options	251	185
Interest rate swap designated as cash flow hedge	265	0
Lease liability	1,113	1,121
Accrued compensation	430	0
Other	224	351
Total deferred tax assets	8,814	6,038
Deferred Tax Liabilities
Loan origination costs	(2,134)	(1,341)
Servicing rights	(2,708)	(2,525)
Stock dividend - FHLB stock	(55)	(59)
Property, plant, and equipment	(1,097)	(1,362)
Purchase accounting adjustments	(830)	(1,404)
Securities available-for-sale	(958)	(216)
Lease right-of-use assets	(1,090)	(1,078)
Other	0	(24)
Total deferred tax liabilities	(8,872)	(8,009)
Net deferred tax liabilities	$ (58)	$ (1,971)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
INCOME TAXES
Uncertain tax liabilities	$ 0	$ 0
Recognized interest and penalties	0	$ 0
Net operating loss carryforwards	$ 2,400

Commitments and Contingencies -

Commitments and Contingencies - Commitment (Details) - Commitments to Extend Credit - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	$ 528,231	$ 312,272
REAL ESTATE LOANS.
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	345,786	183,477
Commercial Real Estate
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	1,293	247
Construction and development
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	143,666	95,031
One-to-four-family
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	147,712	39,697
Home equity.
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	52,457	47,880
Multi-family
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	658	622
CONSUMER LOANS.
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	23,365	22,176
COMMERCIAL BUSINESS LOANS.
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	159,080	106,619
Commercial and industrial
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	106,171	72,731
Warehouse lending
Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments	$ 52,909	$ 33,888

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Amount of loans sold to FHLB	$ 30,000,000
Federal Home Loan Bank, First Loss Account Established	938,000
Bank recourse obligation	$ 811,000
Bank recourse obligation, percentage of loans outstanding	2.70%
Reserve as a percentage of outstanding CE	10.00%
Reserve for loans sold	$ 272,000
Outstanding delinquencies on loans sold to Federal Home Loan Bank	$ 498,000	$ 0
Change of control agreement, executive payment, period following change in control (in months)	12 months
Pending material legal actions	0
Maximum
Loss Contingencies [Line Items]
Change of control agreement, executive payment, period prior to change in control (in months)	6 months
Change of control agreement, period of base compensation disbursed as lump sum payment (in months)	12 months
Minimum
Loss Contingencies [Line Items]
Change of control agreement, notice required to cancel agreement (in months)	24 months
Commitments to Extend Credit
Loss Contingencies [Line Items]
Reserve for estimated losses	$ 407,000	293,000
Guarantee on loans sold
Loss Contingencies [Line Items]
Reserve for estimated losses	$ 2,000,000	$ 1,200,000
CEO
Loss Contingencies [Line Items]
Severance agreement, period of base compensation disbursed as lump sum payment (in months)	24 months

Significant Concentration Of _2

Significant Concentration Of Credit Risk (Details)	12 Months Ended
	Dec. 31, 2020
Credit Concentration Risk [Member] | Construction Land Development And Other Land Concentration [Member] | Regulatory Capital [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	89.60%

Regulatory Capital - Regulatory

Regulatory Capital - Regulatory Capital Ratios Policy (Details) $ in Millions	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage capital, Ratio	11.1	11.3
1st Security Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 leverage capital, Ratio	10.9	11.6
Tier One Leverage Capital	$ 215.9	$ 196
Tier 1 leverage capital, To be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 159.1	$ 84.8

Fair Value Measurements - Avail

Fair Value Measurements - Available for Sale Securities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 348,511	$ 196,313
Total liabilities measured at fair value	(2,921)	(203)
Securities available-for-sale. | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	8,105	9,066
Securities available-for-sale. | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	11,000	10,570
Securities available-for-sale. | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	71,857	21,120
Securities available-for-sale. | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	68,187	62,850
Securities available-for-sale. | U.S. Small Business Administration securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	18,869	22,451
Securities available-for-sale. | Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	166,448	69,699
Derivative | Interest rate lock commitments with customers
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	4,024	557
Derivative | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	21
Total liabilities measured at fair value	(1,252)
Derivative | Mandatory and best effort forward commitments with investors
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	(67)	(195)
Derivative | Forward TBA mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	(1,602)	(8)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Total liabilities measured at fair value	0	0
Level 1 | Securities available-for-sale. | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		0
Level 1 | Securities available-for-sale. | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 1 | Securities available-for-sale. | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 1 | Securities available-for-sale. | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 1 | Securities available-for-sale. | U.S. Small Business Administration securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 1 | Securities available-for-sale. | Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 1 | Derivative | Interest rate lock commitments with customers
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 1 | Derivative | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0
Total liabilities measured at fair value	0
Level 1 | Derivative | Mandatory and best effort forward commitments with investors
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	0	0
Level 1 | Derivative | Forward TBA mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	343,376	194,594
Total liabilities measured at fair value	(2,854)	(8)
Level 2 | Securities available-for-sale. | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	8,105	9,066
Level 2 | Securities available-for-sale. | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	10,016	9,546
Level 2 | Securities available-for-sale. | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	71,730	20,982
Level 2 | Securities available-for-sale. | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	68,187	62,850
Level 2 | Securities available-for-sale. | U.S. Small Business Administration securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	18,869	22,451
Level 2 | Securities available-for-sale. | Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	166,448	69,699
Level 2 | Derivative | Interest rate lock commitments with customers
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 2 | Derivative | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	21
Total liabilities measured at fair value	(1,252)
Level 2 | Derivative | Mandatory and best effort forward commitments with investors
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	0	0
Level 2 | Derivative | Forward TBA mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	(1,602)	(8)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,135	1,719
Total liabilities measured at fair value	(67)	(195)
Level 3 | Securities available-for-sale. | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value		0
Level 3 | Securities available-for-sale. | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	984	1,024
Level 3 | Securities available-for-sale. | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	127	138
Level 3 | Securities available-for-sale. | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 3 | Securities available-for-sale. | U.S. Small Business Administration securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 3 | Securities available-for-sale. | Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0	0
Level 3 | Derivative | Interest rate lock commitments with customers
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	4,024	557
Level 3 | Derivative | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0
Total liabilities measured at fair value	0
Level 3 | Derivative | Mandatory and best effort forward commitments with investors
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	(67)	(195)
Level 3 | Derivative | Forward TBA mortgage backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities measured at fair value	$ 0	$ 0

Fair Value Measurements - Impai

Fair Value Measurements - Impaired Loans and OREO (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
OREO	$ 90	$ 168
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	7,761	3,128
OREO	90	168
Servicing Rights	12,833	13,255
Fair Value, Measurements, Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
OREO	0	0
Servicing Rights	0	0
Fair Value, Measurements, Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
OREO	0	0
Servicing Rights	0	0
Fair Value, Measurements, Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	7,761	3,128
OREO	90	168
Servicing Rights	$ 12,833	$ 13,255

Fair Value Measurements - Disco

Fair Value Measurements - Discount Rate (Details)	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Measurements, Recurring | Interest rate lock commitments with customers
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input [Extensible List]	fsbw:MeasurementInputPullThroughExpectationsMember
Debt Securities, Available-for-sale, Valuation Technique [Extensible List]	fsbw:QuotedMarketPricesMember
Fair Value, Measurements, Recurring | Individual forward commitments with investors
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input [Extensible List]	fsbw:MeasurementInputPullThroughExpectationsMember
Debt Securities, Available-for-sale, Valuation Technique [Extensible List]	fsbw:QuotedMarketPricesMember
Fair Value, Measurements, Recurring | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input [Extensible List]	us-gaap:MeasurementInputDiscountRateMember
Debt Securities, Available-for-sale, Valuation Technique [Extensible List]	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair Value, Measurements, Recurring | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input [Extensible List]	us-gaap:MeasurementInputDiscountRateMember
Debt Securities, Available-for-sale, Valuation Technique [Extensible List]	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Fair Value, Measurements, Nonrecurring | Impaired Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input [Extensible List]	Discount applied to the obtained appraisal
Debt Securities, Available-for-sale, Valuation Technique [Extensible List]	fsbw:FairValueOfUnderlyingCollateralMember
Fair Value, Measurements, Nonrecurring | Other Real Estate Owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input [Extensible List]	Discount applied to the obtained appraisal
Debt Securities, Available-for-sale, Valuation Technique [Extensible List]	fsbw:FairValueOfUnderlyingCollateralMember
Fair Value, Measurements, Nonrecurring | Servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input [Extensible List]	fsbw:PrepaymentSpeedsMember
Debt Securities, Available-for-sale, Valuation Technique [Extensible List]	fsbw:IndustrySourcesMember
Level 3 | Fair Value, Measurements, Recurring | Interest rate lock commitments with customers | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	0.80	0.80
Level 3 | Fair Value, Measurements, Recurring | Interest rate lock commitments with customers | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	0.99	0.99
Level 3 | Fair Value, Measurements, Recurring | Interest rate lock commitments with customers | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	91.6	94.5
Level 3 | Fair Value, Measurements, Recurring | Individual forward commitments with investors | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	0.80	0.80
Level 3 | Fair Value, Measurements, Recurring | Individual forward commitments with investors | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	0.99	0.99
Level 3 | Fair Value, Measurements, Recurring | Individual forward commitments with investors | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	91.6	94.5
Level 3 | Fair Value, Measurements, Recurring | Corporate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	2.5	2.5
Level 3 | Fair Value, Measurements, Recurring | Corporate securities | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	2.5	2.1
Level 3 | Fair Value, Measurements, Recurring | Municipal bonds | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	6.4	6.4
Level 3 | Fair Value, Measurements, Recurring | Municipal bonds | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	6.4	3.4
Level 3 | Fair Value, Measurements, Nonrecurring | Impaired Loans | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	10	10
Level 3 | Fair Value, Measurements, Nonrecurring | Impaired Loans | Discount applied to the obtained appraisal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	10	10
Level 3 | Fair Value, Measurements, Nonrecurring | Other Real Estate Owned | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	10	10
Level 3 | Fair Value, Measurements, Nonrecurring | Other Real Estate Owned | Discount applied to the obtained appraisal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	10	10
Level 3 | Fair Value, Measurements, Nonrecurring | Servicing rights | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	0	0
Level 3 | Fair Value, Measurements, Nonrecurring | Servicing rights | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	0.50	0.50
Level 3 | Fair Value, Measurements, Nonrecurring | Servicing rights | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement inputs (as a percent)	32.6	17.1

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Level 3 on recurring basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Interest rate lock commitments with customers
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 557	$ 503
Purchases and Issuances	53,281	11,063
Sales and Settlements	(49,814)	(11,009)
Ending Balance	4,024	557
Net change in fair value for gains/(losses) relating to items held at end of period included in income	3,467	54
Individual forward commitments with investors
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	(195)	(34)
Purchases and Issuances	(4,857)	(1,444)
Sales and Settlements	4,985	1,283
Ending Balance	(67)	(195)
Net change in fair value for gains/(losses) relating to items held at end of period included in income	128	(161)
Securities available-for-sale.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,162
Sales and Settlements	(51)
Transfers In		1,162
Ending Balance	1,111	$ 1,162
Net change in fair value for gains/(losses) relating to items held at end of period included in other comprehensive	$ (40)

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value By Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financial Assets
Certificates of deposit at other financial institutions	$ 12,278	$ 20,902
Securities available-for-sale, at fair value	178,018	126,057
Securities held-to-maturity (fair value of $7,556)	7,500	0
Loans held for sale, at fair value	166,448	69,699
Fair Value, Measurements, Recurring
Financial Liabilities
Financial Liabilities Fair Value Disclosure	2,921	203
Level 1 | Fair Value, Measurements, Recurring
Financial Liabilities
Financial Liabilities Fair Value Disclosure	0	0
Level 2 | Fair Value, Measurements, Recurring
Financial Liabilities
Financial Liabilities Fair Value Disclosure	2,854	8
Level 3 | Fair Value, Measurements, Recurring
Financial Liabilities
Financial Liabilities Fair Value Disclosure	67	195
Carrying Amount | Level 1
Financial Assets
Cash and cash equivalents	91,576	45,778
Certificates of deposit at other financial institutions	12,278	20,902
Carrying Amount | Level 2
Financial Assets
Securities available-for-sale, at fair value	176,907	124,895
Securities held-to-maturity (fair value of $7,556)	7,500
Loans held for sale, at fair value	166,448	69,699
FHLB stock, at cost	7,439	8,045
Interest rate swaps	21
Accrued interest receivable	7,030	5,908
Financial Liabilities
Deposits	1,674,071	1,392,408
Borrowings	165,809	84,864
Subordinated note, net	10,000	9,885
Accrued interest payable	406	273
Interest rate swaps	1,252
Forward TBA mortgage-backed securities	1,602	8
Carrying Amount | Level 3
Financial Assets
Securities available-for-sale, at fair value	1,111	1,162
Loans receivable, gross	1,574,227	1,351,893
Servicing rights, held at lower of cost or fair value	12,595	11,560
Fair value interest rate locks with customers	4,024	557
Financial Liabilities
Mandatory and best effort forward commitments with investors	67	195
Fair Value | Level 1
Financial Assets
Cash and cash equivalents	91,576	45,778
Certificates of deposit at other financial institutions	12,278	20,902
Fair Value | Level 2
Financial Assets
Securities available-for-sale, at fair value	176,907	124,895
Securities held-to-maturity (fair value of $7,556)	7,556
Loans held for sale, at fair value	166,448	69,699
FHLB stock, at cost	7,439	8,045
Interest rate swaps	21
Accrued interest receivable	7,030	5,908
Financial Liabilities
Deposits	1,674,328	1,385,658
Borrowings	167,680	85,268
Subordinated note, net	11,083	10,599
Accrued interest payable	406	273
Interest rate swaps	1,252
Forward TBA mortgage-backed securities	1,602	8
Fair Value | Level 3
Financial Assets
Securities available-for-sale, at fair value	1,111	1,162
Loans receivable, gross	1,580,360	1,377,408
Servicing rights, held at lower of cost or fair value	12,833	13,255
Fair value interest rate locks with customers	4,024	557
Financial Liabilities
Mandatory and best effort forward commitments with investors	$ 67	$ 195

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator (in thousands):
Net Income	$ 39,264	$ 22,717
Dividends and undistributed earnings allocated to participating securities	(192)	(73)
Net income available to common shareholders	$ 39,072	$ 22,644
Denominator (shown as actual):
Basic weighted average common shares outstanding (in shares)	4,273,350	4,414,032
Dilutive shares (in shares)	81,019	108,992
Diluted weighted average common shares outstanding (in shares)	4,354,369	4,523,024
Basic earnings per share(in dollars per share)	$ 9.14	$ 5.13
Diluted earnings per share(in dollars per share)	$ 8.97	$ 5.01
Potentially dilutive weighted average share options that were not included in the computation of diluted earnings per share because to do so would be anti-dilutive	66,619	36,337

Derivatives (Details)

Derivatives (Details)	12 Months Ended
	Dec. 31, 2020USD ($)security	Dec. 31, 2019USD ($)
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 6,300,000	$ 303,000
Asset pledged as collateral
Derivative [Line Items]
Number of securities pledged | security	2
Carrying value of assets pledged	$ 3,400,000
Cash Flow Hedges
Derivative [Line Items]
Net unrealized loss on cash flow hedges recorded in accumulated other comprehensive income	(967,000)
Reclassification of loss to interest expense related to cash flow hedges	(198,000)
Reclassification to interest expense related to cash flow hedges over next 12 months	(492,000)
Cash flow hedges		0
Forward TBA mortgage-backed securities
Derivative [Line Items]
Margin collateral	$ 3,300,000	$ 1,200,000

Derivatives - Derivative instru

Derivatives - Derivative instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Designated as Hedging Instrument | Interest rate lock commitments with customers | Cash Flow Hedges
Derivative [Line Items]
Notional	$ 90,000
Fair Value, Asset	21
Fair Value, Liability	1,252
Not Designated as Hedging Instrument | Interest rate lock commitments with customers
Derivative [Line Items]
Notional	136,739	$ 33,914
Fair Value, Asset	4,024	557
Fair Value, Liability	0	0
Not Designated as Hedging Instrument | Mandatory and best effort forward commitments with investors
Derivative [Line Items]
Notional	25,027	43,752
Fair Value, Asset	0	0
Fair Value, Liability	67	195
Not Designated as Hedging Instrument | Mortgage-backed securities
Derivative [Line Items]
Notional	232,000	46,000
Fair Value, Asset	0	0
Fair Value, Liability	1,602	8
Not Designated as Hedging Instrument | Forward TBA mortgage-backed securities
Derivative [Line Items]
Notional	$ 232,000	$ 46,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 200,242	$ 180,038
Net current period other comprehensive income (loss)	1,745	2,267
Balance	230,007	200,242
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassification, net of tax	(1,122)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	155
Net current period other comprehensive income (loss)	(967)
Balance	(967)
Unrealized Gains and Losses on Available for Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	788	(1,479)
Other comprehensive income (loss) before reclassification, net of tax	2,947	2,292
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(235)	(25)
Net current period other comprehensive income (loss)	2,712	2,267
Balance	3,500	788
Accumulated Other Comprehensive (Loss) Income, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	788	(1,479)
Other comprehensive income (loss) before reclassification, net of tax	1,825	2,292
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(80)	(25)
Net current period other comprehensive income (loss)	1,745	2,267
Balance	$ 2,533	$ 788

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($)	Aug. 15, 2020	Sep. 30, 2013	Dec. 31, 2020	Dec. 31, 2019	May 17, 2018	May 08, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award contractual life			10 years
2013 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected forfeiture rate over contractual term			3.10%
2013 Equity Incentive Plan | Equity option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		324,013
Market value of stock (in dollars per share)						$ 16.89
Granted (in shares)		322,000
Shares available for grant			6,013
2013 Equity Incentive Plan | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		129,605
2018 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 1,000,000	$ 869,000
2018 Equity Incentive Plan | Equity option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant			274,060
Unrecognized compensation cost, nonvested awards			$ 1,500,000
Remaining weighted-average vesting period			3 years 4 months 24 days
Shares	62,285
2018 Equity Incentive Plan | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)					163,000
Shares available for grant			92,905
Unrecognized compensation cost, nonvested awards			$ 2,400,000
Shares	24,880
2018 Equity Incentive Plan | Restricted stock awards | Directors Excluding CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			1 year
2018 Equity Incentive Plan | Equity option and restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)					650,000
Market value of stock (in dollars per share)	$ 42.70
2013 and 2018 Equity Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit from share-based compensation expense			$ 214,000	$ 182,000
Expected term in years				6 years 9 months 7 days
Remaining weighted-average vesting period			6 years 6 months 29 days
Total intrinsic value of options exercised			$ 453,674
2013 and 2018 Equity Incentive Plans | Equity option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award contractual life			10 years
Expiration period			10 years
2013 and 2018 Equity Incentive Plans | Equity option and restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			62,285
Maximum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term in years			6 years 6 months	6 years 6 months
One year vesting | 2013 and 2018 Equity Incentive Plans | Stock Options | Directors Excluding CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			1 year
One year vesting | 2013 and 2018 Equity Incentive Plans | Equity option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term in years			5 years 6 months
One year vesting | 2013 and 2018 Equity Incentive Plans | Equity option | Directors Excluding CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			1 year
Five year vesting | 2013 and 2018 Equity Incentive Plans | Equity option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual award vesting percentage			20.00%
Expected term in years			6 years 6 months
Five year vesting | 2013 and 2018 Equity Incentive Plans | Equity option | Directors Excluding CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			5 years
Five year vesting | 2013 and 2018 Equity Incentive Plans | Equity option | Officers And Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			5 years

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value of Options (Details) - Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	1.97%	1.23%
Weighted-average grant date fair value per option granted	$ 8	$ 8.80
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	26.79%	18.90%
Risk-free interest rate	0.42%	1.45%
Expected term in years	6 years 6 months	6 years 6 months

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Shares
Award contractual life	10 years
2013 Equity Incentive Plan
Shares
Annual forfeiture rate	0.31%
Expected forfeiture rate over contractual term	3.10%
2013 and 2018 Equity Incentive Plans
Shares
Outstanding, beginning balance (in shares)	287,990
Less exercised (in shares)	14,398
Forfeited or Expired, Shares	0
Outstanding, ending balance (in shares)	335,877	287,990
Expected to vest, assuming a 0.31% annual forfeiture rate (in shares)	334,824
Exercisable (in shares)	174,988
Weighted-Average Exercise Price
Outstanding, beginning balance (in dollars per share)	$ 36.98
Granted (in dollars per share)	42.70
Less exercised (in dollars per share)	16.89
Forfeited or expired, Weighted-Average Exercise Price (in dollars per share)	0
Outstanding, ending balance (in dollars per share)	38.90	$ 36.98
Expected to vest, assuming a 0.31% annual forfeiture rate (in dollars per share)	38.87
Exercisable (in dollars per share)	$ 28.62
Weighted-Average Remaining Contractual Term In Years
Outstanding, beginning balance		6 years 9 months 7 days
Granted	6 years 5 months 12 days
Outstanding, ending balance	6 years 6 months 29 days
Expected to vest, assuming a 0.31% annual forfeiture rate, Weighted Average Remaining Contractual Term	6 years 6 months 29 days
Exercisable	4 years 8 months 8 days
Aggregate Intrinsic Value
Beginning balance	$ 7,722,369
Less exercised	453,674
Forfeited or Expired, Aggregate Intrinsic Value	0
Ending balance	5,721,159	$ 7,722,369
Expected to vest, assuming a 0.31% annual forfeiture rate	5,713,654
Exercisable	$ 4,733,571

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Awards (Details) - Restricted stock awards	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Shares
Nonvested, Beginning balance (in shares) | shares	40,215
Granted (shares) | shares	24,880
Less vested (in shares) | shares	10,003
Nonvested, Ending balance (in shares) | shares	55,092
Weighted-Average Grant-Date Fair Value Per Share
Nonvested, Beginning balance (in dollars per share) | $ / shares	$ 53.64
Granted (in dollars per share) | $ / shares	42.70
Less vested (in dollars per share) | $ / shares	53.67
Nonvested, Ending balance (in dollars per share) | $ / shares	$ 48.70
2018 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	3 years 7 months 6 days
2018 Equity Incentive Plan | Directors Excluding CEO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
2018 Equity Incentive Plan | Directors And Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years

Business Segments - Narrative (

Business Segments - Narrative (Details)	12 Months Ended
	Dec. 31, 2020itemsegment
Segment Reporting Information [Line Items]
Number of operating segments | segment	2
Retail Deposit | Pacific Northwest
Segment Reporting Information [Line Items]
Number of bank branches | item	21

Business Segments - Segment Fin

Business Segments - Segment Financial Results (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)employee	Dec. 31, 2019USD ($)item
Segment Reporting Information [Line Items]
Net interest income	$ 74,120	$ 70,308
Provision for loan losses	(13,036)	(2,880)
Noninterest income	55,359	23,035
Noninterest expense	(66,593)	(62,333)
INCOME BEFORE PROVISION FOR INCOME TAXES	49,850	28,130
Provision for income taxes	(10,586)	(5,413)
NET INCOME	39,264	22,717
Total assets	2,113,241	1,713,056
Total average assets for year ended	$ 1,940,048	$ 1,650,369
FTEs	506	452
Home Lending
Segment Reporting Information [Line Items]
Net interest income	$ 5,123	$ 6,307
Provision for loan losses	(2,758)	(433)
Noninterest income	44,808	13,209
Noninterest expense	(17,351)	(14,283)
INCOME BEFORE PROVISION FOR INCOME TAXES	29,822	4,800
Provision for income taxes	(6,333)	(924)
NET INCOME	23,489	3,876
Total assets	460,409	312,404
Total average assets for year ended	$ 396,367	$ 272,901
FTEs	152	127
Commercial and Consumer Banking
Segment Reporting Information [Line Items]
Net interest income	$ 68,997	$ 64,001
Provision for loan losses	(10,278)	(2,447)
Noninterest income	10,551	9,826
Noninterest expense	(49,242)	(48,050)
INCOME BEFORE PROVISION FOR INCOME TAXES	20,028	23,330
Provision for income taxes	(4,253)	(4,489)
NET INCOME	15,775	18,841
Total assets	1,652,832	1,400,652
Total average assets for year ended	$ 1,543,681	$ 1,377,468
FTEs	354	325

Revenue From Contracts With C_3

Revenue From Contracts With Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Noninterest Income
Noninterest Income (in-scope of Topic 606)	$ 2,665	$ 2,913
Noninterest income (out-of-scope of Topic 606)	52,694	20,122
Total noninterest income	55,359	23,035
Debit Card Interchange Fees
Noninterest Income
Noninterest Income (in-scope of Topic 606)	1,879	1,848
Deposit service and account maintenance fees
Noninterest Income
Noninterest Income (in-scope of Topic 606)	$ 786	$ 1,065

Goodwill and other Intangible_3

Goodwill and other Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 2,312,000	$ 2,312,000
Goodwill, Impairment Loss	0	0
Finite-Lived Intangible Assets, Net [Abstract]
Finite-Lived Intangible Assets, Gross, Total	7,490,000	7,490,000	$ 7,490,000
Finite-Lived Intangible Assets, Accumulated Amortization	(2,739,000)	(2,033,000)	(1,273,000)
Core deposit intangible, net	4,751,000	5,457,000	6,217,000
Amortization	(706,000)	(760,000)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2021	691,000
2022	691,000
2023	691,000
2024	621,000
2025	525,000
Thereafter	1,532,000
Total	$ 4,751,000	5,457,000	$ 6,217,000
Anchor Bancorp
Finite-Lived Intangible Assets, Net [Abstract]
Amortization period	10 years
Bank of America
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 2,300,000	$ 2,300,000
Finite-Lived Intangible Assets, Net [Abstract]
Amortization period	9 years

Parent Company Only Financial_3

Parent Company Only Financial Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 11,554	$ 13,175
Other assets	9,705	11,682
TOTAL ASSETS	2,113,241	1,713,056
Liabilities and Stockholders' Equity
Subordinated note, net	10,000	9,885
Other liabilities	28,120	18,472
Total liabilities	1,883,234	1,512,814
Total stockholders' equity	230,007	200,242	$ 180,038
Total liabilities and stockholders' equity	2,113,241	1,713,056
FS Bancorp Parent Company
Assets
Cash and due from banks	14,531	5,568
Investment in subsidiary	225,484	204,570
Other assets	202	172
TOTAL ASSETS	240,217	210,310
Liabilities and Stockholders' Equity
Subordinated note, net	10,000	9,885
Other liabilities	210	183
Total liabilities	10,210	10,068
Total stockholders' equity	230,007	200,242
Total liabilities and stockholders' equity	$ 240,217	$ 210,310

Parent Company Only Financial_4

Parent Company Only Financial Information Balance Sheets (Details - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Cash and due from banks	$ 11,554	$ 13,175
Total cash and cash equivalents	91,576	45,778
Certificates of deposit at other financial institutions	12,278	20,902
Securities available-for-sale, at fair value	178,018	126,057
Loans held for sale, at fair value	166,448	69,699
Loans receivable, net	1,544,981	1,336,346
Accrued interest receivable	7,030	5,908
Premises and equipment, net	27,343	28,770
Operating lease right-of-use ("ROU") assets	4,949	5,016
Federal Home Loan Bank ("FHLB") stock, at cost	7,439	8,045
Other real estate owned ("OREO")	90	168
Bank owned life insurance ("BOLI"), net	36,226	35,356
Servicing rights, held at the lower of cost or fair value	12,595	11,560
Goodwill	2,312	2,312
Core deposit intangible, net	4,751	5,457	$ 6,217
Other assets	9,705	11,682
TOTAL ASSETS	2,113,241	1,713,056
LIABILITIES
Noninterest-bearing accounts	362,853	273,602
Interest-bearing accounts	1,311,218	1,118,806
Total deposits	1,674,071	1,392,408
Borrowings	165,809	84,864
Principal amount	10,000	10,000
Unamortized debt issuance costs		(115)
Total subordinated note less unamortized debt issuance costs	10,000	9,885
Operating lease liabilities	5,176	5,214
Deferred tax liability, net	58	1,971
Other liabilities	28,120	18,472
Total liabilities	1,883,234	1,512,814
COMMITMENTS AND CONTINGENCIES (NOTE 12)
STOCKHOLDERS' EQUITY
Preferred stock, $.01 par value; 5,000,000 shares authorized; none issued or outstanding
Common stock, $.01 par value; 45,000,000 shares authorized; 4,237,956 and 4,459,041 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively	42	44
Additional paid-in capital	81,318	89,268
Retained earnings	146,405	110,715
Accumulated other comprehensive income, net of tax	2,533	788
Unearned shares - Employee Stock Ownership Plan ("ESOP")	(291)	(573)
Total stockholders' equity	230,007	200,242	$ 180,038
Total liabilities and stockholders' equity	$ 2,113,241	$ 1,713,056

Parent Company Only Financial_5

Parent Company Only Financial Information - Condensed Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Condensed Income Statements, Captions [Line Items]
Interest from subsidiary	$ 84,128	$ 84,706
Interest expense on subordinated note	(776)	(679)
Dividends received from subsidiary	4,709	4,919
Income tax benefit	10,586	5,413
NET INCOME	39,264	22,717
FS Bancorp Parent Company
Condensed Income Statements, Captions [Line Items]
Interest from subsidiary		2
Interest expense on subordinated note	(776)	(679)
Dividends received from subsidiary	20,862	3,935
Other expenses	(195)	(142)
Income before income tax benefit and equity in undistributed net income of subsidiary	19,891	3,116
Income tax benefit	204	172
Equity in undistributed earnings of subsidiary	19,169	19,429
NET INCOME	$ 39,264	$ 22,717

Parent Company Only Financial_6

Parent Company Only Financial Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 39,264	$ 22,717
ESOP compensation expense for allocated shares	1,307	1,506
Other assets	5,511	(4,589)
Other liabilities	5,714	(2,443)
Net cash (used by) from operating activities	(32,317)	9,177
Cash flows from investing activities:
Net cash used by investing activities	(270,690)	(55,201)
Cash flows used by financing activities:
(Disbursements) proceeds from stock options exercised, net	(161)	705
Common stock repurchased for employee/director taxes paid on restricted stock awards	(34)	(204)
Common stock repurchased	(9,802)	(4,800)
Dividends paid on common stock	(3,574)	(2,856)
Net cash from financing activities	348,805	59,023
NET INCREASE IN CASH AND CASH EQUIVALENTS	45,798	12,999
CASH AND CASH EQUIVALENTS, beginning of year	45,778	32,779
CASH AND CASH EQUIVALENTS, end of year	91,576	45,778
FS Bancorp Parent Company
Cash flows from operating activities:
Net income	39,264	22,717
Equity in undistributed net income of subsidiary	(19,169)	(19,429)
Amortization	115	20
ESOP compensation expense for allocated shares	1,025	1,231
Share-based compensation expense related to stock options and restricted stock	1,020	869
Other assets	(30)	3
Other liabilities	27	11
Net cash (used by) from operating activities	22,252	5,422
Cash flows from investing activities:
Net proceeds from ESOP	282	275
Net cash used by investing activities	282	275
Cash flows used by financing activities:
(Disbursements) proceeds from stock options exercised, net	(161)	705
Common stock repurchased for employee/director taxes paid on restricted stock awards	(34)	(204)
Common stock repurchased	(9,802)	(4,800)
Dividends paid on common stock	(3,574)	(2,856)
Net cash from financing activities	(13,571)	(7,155)
NET INCREASE IN CASH AND CASH EQUIVALENTS	8,963	(1,458)
CASH AND CASH EQUIVALENTS, beginning of year	5,568	7,026
CASH AND CASH EQUIVALENTS, end of year	$ 14,531	$ 5,568