BankFinancial (BFIN) 10-K 11 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 06, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,018
Entity Registrant Name	BankFinancial CORP
Entity Central Index Key	1,303,942
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding		16,457,672
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 257
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Shell Company	false

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and due from other financial institutions	$ 13,805	$ 13,572
Interest-bearing deposits in other financial institutions	84,399	114,020
Cash and cash equivalents	98,204	127,592
Securities, at fair value	88,179	93,383
Loans receivable, net of allowance for loan losses	1,323,793	1,314,651
Other real estate owned, net	1,226	2,351
Stock in Federal Home Loan Bank, at cost	8,026	8,290
Premises held-for-sale	0	5,667
Premises and equipment, net	25,205	24,856
Accrued interest receivable	4,952	4,619
Core deposit intangible	102	286
Bank owned life insurance	18,809	22,859
Deferred Tax Assets, Net	6,235	12,563
Other assets	10,594	8,441
Total assets	1,585,325	1,625,558
Deposits
Noninterest-bearing	230,041	234,354
Interest-bearing	1,122,443	1,105,697
Total deposits	1,352,484	1,340,051
Borrowings	21,049	60,768
Advance payments by borrowers taxes and insurance	10,531	11,645
Accrued interest payable and other liabilities	14,111	15,460
Total liabilities	1,398,175	1,427,924
Commitments and contingent liabilities
Stockholders' equity:
Preferred Stock, $0.01 par value, 25,000,000 shares authorized, none issued or outstanding	0	0
Common Stock, $0.01 par value, 100,000,000 shares authorized; 16,481,514 shares issued at December 31, 2018 and 17,958,723 shares issued at December 31, 2017	165	179
Additional paid-in capital	130,547	153,811
Retained earnings	56,167	43,274
Accumulated other comprehensive income	271	370
Total stockholders' equity	187,150	197,634
Total liabilities and stockholders' equity	$ 1,585,325	$ 1,625,558

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for loan losses	$ 8,470	$ 8,366
Preferred Stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized	25,000,000	25,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock, par value (usd per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	100,000,000	100,000,000
Common Stock, shares issued	16,481,514	17,958,723

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Interest and dividend income
Loans, including fees	$ 57,052,000	$ 53,227,000
Securities	2,229,000	1,474,000
Other	2,006,000	1,478,000
Total interest income	61,287,000	56,179,000
Interest expense
Deposits	8,561,000	5,438,000
Borrowings	656,000	651,000
Total interest expense	9,217,000	6,089,000
Net interest income	52,070,000	50,090,000
Provision for (recovery of) loan losses	145,000	(87,000)
Net interest income	51,925,000	50,177,000
Noninterest income
Deposit service charges and fees	3,968,000	3,953,000
Loan servicing fees	439,000	326,000
Commerical mortgage brokerage fees	138,000	0
Mortgage brokerage and banking fees	119,000	215,000
Gain on sale of equity securities	3,558,000	0
Unrealized gains on equity securities	3,427,000	0
Gain on sale of premises held-for-sale	93,000	0
Earnings on bank owned life insurance	174,000	265,000
Bank-owned life insurance death benefit	1,389,000	0
Other	635,000	678,000
Total noninterest income	14,877,000	6,408,000
Noninterest expense
Compensation and benefits	22,987,000	21,767,000
Office occupancy and equipment	6,817,000	6,623,000
Advertising and public relations	848,000	1,004,000
Information technology	2,792,000	2,743,000
Supplies, telephone, and postage	1,433,000	1,366,000
Amortization of intangibles	184,000	496,000
Nonperforming asset management	353,000	340,000
Operations of other real estate owned	432,000	923,000
FDIC insurance premiums	437,000	587,000
Other	4,471,000	4,542,000
Total noninterest expense	40,754,000	40,391,000
Income (loss) before income taxes	26,048,000	16,194,000
Income tax expense	6,706,000	7,190,000
Net income (loss)	$ 19,342,000	$ 9,004,000
Basic earnings (loss) per common share (usd per share)	$ 1.11	$ 0.49
Diluted earnings (loss) per common share (usd per share)	$ 1.11	$ 0.49
Weighted average common shares outstanding (shares)	17,434,345	18,279,899
Diluted weighted average common shares outstanding (shares)	17,434,345	18,280,336
Loan Servicing [Member]
Noninterest income
Trust	$ 937,000	$ 971,000

Consolidated Statements Compreh

Consolidated Statements Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 19,342	$ 9,004
Unrealized holding loss on securities arising during the period	(136)	(102)
Tax effect	37	36
Comprehensive loss, net of tax	(99)	(66)
Other comprehensive loss	(99)	(66)
Comprehensive income	$ 19,243	$ 8,938

Consolidated Statements of Chan

Consolidated Statements of Changes In Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Unearned Employee Stock Ownership Plan Shares	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2016	$ 204,780	$ 192	$ 173,047	$ 39,483	$ (8,318)	$ 376
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,004	0	0	9,004	0	0
Other comprehensive loss, net of tax effect	(66)	0	0	0	0	(66)
Net exercise of stock options (198,026 shares)	(1,237)	2	(1,239)
Prepayment of ESOP Share Acquisition Loan	1,125	(8)	(7,185)		8,318
Repurchase and retirement of common stock	(10,819)	(7)	(10,812)	0	0	0
Cash dividends declared on common stock	(5,153)	0	0	(5,153)	0	0
Ending Balance at Dec. 31, 2017	197,634	179	153,811	43,274	0	370
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	19,342	0	0	19,342	0	0
Other comprehensive loss, net of tax effect	(99)	0	0	0	0	(99)
Prepayment of ESOP Share Acquisition Loan	0
Nonvested stock awards-stock-based compensation expense	6	0	6	0	0	0
Repurchase and retirement of common stock	(23,284)	(14)	(23,270)	0	0	0
Cash dividends declared on common stock	(6,449)	0	0	(6,449)	0	0
Ending Balance at Dec. 31, 2018	$ 187,150	$ 165	$ 130,547	$ 56,167	$ 0	$ 271

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Purchase and retirement of common stock (shares)	719,573	1,063,557
Cash dividends declared on common stock (usd per share)	$ 0.28	$ 0.21
Stock options exercised (in shares)	1,752,156	198,026

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income	$ 19,342,000	$ 9,004,000
Adjustments to reconcile to net loss to net cash from operating activities
Provision for (recovery of) loan losses	145,000	(87,000)
Prepayment of ESOP Share Acquisition Loan	0	1,125,000
Stock-based compensation expense	6,000	0
Depreciation and amortization	3,323,000	3,789,000
Amortization and accretion on securities and loans	11,000	(123,000)
Amortization of intangibles	184,000	496,000
Amortization and impairment of servicing assets	94,000	109,000
Net change in net deferred loan origination costs	197,000	397,000
Net loss on sale of other real estate owned	56,000	45,000
Net gain on sale of loans	0	(76,000)
Net gain on sale of equity securities	(3,558,000)	0
Net gain on disposition of premises held-for-sale	(93,000)	0
Loans originated for sale	0	(1,288,000)
Proceeds from sale of loans	0	1,364,000
Other real estate owned valuation adjustments	27,000	333,000
Net change in:
Deferred income tax	6,328,000	9,848,000
Accrued interest receivable	(333,000)	(238,000)
Earnings on bank owned life insurance	(174,000)	(265,000)
Other assets	(94,000)	(3,406,000)
Accrued interest payable and other liabilities	(1,349,000)	1,703,000
Net Cash Provided by (Used in) Operating Activities	20,685,000	22,730,000
Securities
Proceeds from maturities	114,583,000	75,460,000
Proceeds from principal repayments	3,587,000	3,388,000
Proceeds from sales of securities	4,059,000	0
Purchases of securities	(113,614,000)	(65,128,000)
Loans receivable
Loan participations sold	0	3,615,000
Principal payments on loans receivable	984,166,000	654,702,000
Purchases of loans	0	(23,451,000)
Originated for investment	(995,257,000)	(640,340,000)
Payments for (Proceeds from) Federal Home Loan Bank Stock	(1,312,000)	(3,514,000)
Purchase of FHLB and FRB stock	(1,048,000)	(154,000)
Proceeds from sale of other real estate owned	2,172,000	3,932,000
Purchases of premises and equipment, net	(1,609,000)	(1,133,000)
Net cash from (used in) investing activities	8,060,000	14,405,000
Cash flows from financing activities
Net change in deposits	12,433,000	661,000
Net change in borrowings	(39,719,000)	9,699,000
Net change in advance payments by borrowers for taxes and insurance	(1,114,000)	604,000
Repurchase and retirement of common stock	(23,284,000)	(10,819,000)
Cash dividends paid on common stock	(6,449,000)	(5,153,000)
Shares retired for tax liability	0	(1,219,000)
Net cash used in financing activities	(58,133,000)	(6,227,000)
Net change in cash and cash equivalents	(29,388,000)	30,908,000
Beginning cash and cash equivalents	127,592,000	96,684,000
Ending cash and cash equivalents	98,204,000	127,592,000
Supplemental disclosures of cash flow information:
Interest paid	9,073,000	6,044,000
Income taxes paid	342,000	427,000
Income taxes refunded	0	6,000
Loans transferred to other real estate owned	1,482,000	2,766,000
Transfer of Property to Held-for-sale	$ 0	$ 5,677,000

Summary of Significant Accounti

Summary of Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Basis of Presentation : BankFinancial Corporation, a Maryland corporation headquartered in Burr Ridge, Illinois (the “Company”), is the owner of all of the issued and outstanding capital stock of BankFinancial, National Association (the “Bank”). BankFinancial Corporation is a registered Bank Holding Company and its wholly-owned bank subsidiary is operating as BankFinancial, National Association. Principles of Consolidation : The consolidated financial statements include the accounts of and transactions of BankFinancial Corporation, the Bank, and the Bank’s wholly-owned subsidiaries, Financial Assurance Services, Inc. and BFIN Asset Recovery Company, LLC (formerly BF Asset Recovery Corporation) (collectively, “the Company”) and have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All significant intercompany accounts and transactions have been eliminated. Nature of Business : The Company’s revenues, operating income, and assets are primarily from the banking industry. Loan origination customers are mainly located in the greater Chicago metropolitan area. To supplement loan originations, the Company purchases loans. The loan portfolio is concentrated in loans that are primarily secured by real estate. Use of Estimates : To prepare financial statements in conformity with GAAP, management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ. Interest-bearing Deposits in Other Financial Institutions : Interest-bearing deposits in other financial institutions maturing in less than 90 days are carried at cost. Cash Flows : Cash and cash equivalents include cash, deposits with other financial institutions maturing in less than 90 days, and daily federal funds sold. Net cash flows are reported for customer loan and deposit transactions, interest bearing deposits in other financial institutions, borrowings, and advance payments by borrowers for taxes and insurance. Securities available-for -sale : Debt securities are classified as available-for-sale when they might be sold before maturity. Prior to January 1, 2018, equity securities with readily determinable fair values were classified as available-for-sale. Securities available-for-sale are carried at fair value, with unrealized holding gains and losses reported in other comprehensive income (loss), net of tax. Interest income includes amortization of purchase premium or discount. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Gains and losses on sales are based on the amortized cost of the security sold. Declines in the fair value of securities below their cost that are other-than-temporary are reflected as realized losses. In determining if losses are other-than-temporary, management considers: (1) the length of time and extent that fair value has been less than cost or adjusted cost, as applicable, (2) the financial condition and near term prospects of the issuer, and (3) whether the Company has the intent to sell the debt security or it is more likely than not that the Company will be required to sell the debt security before the anticipated recovery. Securities also include investments in certificates of deposit with maturities of greater than 90 days. These certificates of deposit are placed with insured institutions for varying maturities and amounts that are fully insured by the Federal Deposit Insurance Corporation (“FDIC”). Equity Securities : Following our adoption of ASU 2016-01 on January 1, 2018, as described in " Recent Accounting Pronouncements ", we account for our investments in equity securities in accordance with ASC 321-10 Investments - Equity Securities. Our equity securities may be classified into two categories and accounted for as follows: • Equity securities with a readily determinable fair value are reported at fair value, with unrealized gains and losses included in earnings. Any dividends received are recorded in interest income. • Equity securities without a readily determinable fair value are reported at their cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer and their impact on fair value. Any dividends received are recorded in interest income. In 2018, equity investments include our investment in Visa Class B shares. The fair value of equity investments with readily determinable fair values is primarily obtained from third-party pricing services. For equity investments without readily determinable fair values, when an orderly transaction for the identical or similar investment of the same issuer is identified, we use the valuation techniques permitted under ASC 820 Fair Value to evaluate the observed transaction(s) and adjust the fair value of the equity investment. ASC 321-10 also provides guidance related to accounting for impairment of equity securities without readily determinable fair values. The qualitative assessment to determine whether impairment exists requires the use of our judgment in certain circumstances. If, after completing the qualitative assessment we conclude an equity investment without a readily determinable fair value is impaired, a loss for the difference between the equity investment’s carrying value and its fair value may be recognized as a reduction to noninterest income in the Consolidated Statements of Operations. Federal Home Loan Bank (“FHLB”) Stock : The Bank is a member of the FHLB system. Members are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest in additional amounts. FHLB stock is carried at cost, classified as a restricted security, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income. Federal Reserve Bank (“FRB”) Stock : The Bank is a member of its regional Federal Reserve Bank. FRB stock is carried at cost, classified as a restricted security, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income. Loans and Loan Income : Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal balance outstanding, net of the allowance for loan losses, premiums and discounts on loans purchased, and net deferred loan costs. Interest income on loans is recognized in income over the term of the loan based on the amount of principal outstanding. Premiums and discounts associated with loans purchased are amortized over the contractual term of the loan using the level–yield method. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level‑yield method without anticipating prepayments. Interest income is reported on the interest method. Interest income is discontinued at the time a loan is 90 days past due or when we do not expect to receive full payment of interest or principal. Past due status is based on the contractual terms of the loan. All interest accrued but not received for loans that have been placed on nonaccrual status is reversed against interest income. Interest received on such loans is accounted for on the cash–basis or cost–recovery method until qualifying for return to accrual status. Once a loan is placed on nonaccrual status, the borrower must generally demonstrate at least six months of payment performance before the loan is eligible to return to accrual status. Generally, the Company utilizes the “90 days delinquent, still accruing” category of loan classification when: (1) the loan is repaid in full shortly after the period end date; (2) the loan is well secured and there are no asserted or pending legal barriers to its collection; or (3) the borrower has remitted all scheduled payments and is otherwise in substantial compliance with the terms of the loan, but the processing of payments actually received or the renewal of a loan has not occurred for administrative reasons. Impaired Loans: Impaired loans principally consist of nonaccrual loans and troubled debt restructurings (“TDRs”). A loan is considered impaired when, based on current information and events, management believes that it is probable that we will be unable to collect all amounts due (both principal and interest) according to the original contractual terms of the loan agreement. Once a loan is determined to be impaired, the amount of impairment is measured based on the loan's observable fair value, the fair value of the underlying collateral less selling costs if the loan is collateral-dependent, or the present value of expected future cash flows discounted at the loan's effective interest rate. If the measurement of the impaired loan is less than the recorded investment in the loan, the bank's allowance for the impaired collateral dependent loan under ASC 310-10-35 is based on fair value (less costs to sell), but the charge-off (the confirmed “loss”) is based on the appraised value. The remaining recorded investment in the loan after the charge-off will have a loan loss allowance for the amount by which the estimated fair value of the collateral (less costs to sell) is less than its appraised value. Impaired loans with specific reserves are reviewed quarterly for any changes that would affect the specific reserve. Any impaired loan for which a determination has been made that the economic value is permanently reduced is charged-off against the allowance for loan losses to reflect its current economic value in the period in which the determination has been made. At the time a collateral-dependent loan is initially determined to be impaired, we review the existing collateral appraisal. If the most recent appraisal is greater than a year old, a new appraisal is obtained on the underlying collateral. Appraisals are updated with a new independent appraisal at least annually and are formally reviewed by our internal appraisal department upon receipt of a new appraisal. All impaired loans and their related reserves are reviewed and updated each quarter. Troubled Debt Restructurings : A loan is classified as a troubled debt restructuring when a borrower is experiencing financial difficulties that leads to a restructuring of the loan, and the Company grants concessions to the borrower in the restructuring that it would not otherwise consider. These concessions may include rate reductions, principal forgiveness, extension of maturity date and other actions intended to minimize potential losses. In determining whether a debtor is experiencing financial difficulties, the Company considers if the debtor is in payment default or would be in payment default in the foreseeable future without the modification, the debtor declared or is in the process of declaring bankruptcy, there is substantial doubt that the debtor will continue as a going concern, the debtor has securities that have been or are in the process of being delisted, the debtor's entity-specific projected cash flows will not be sufficient to service any of its debt, or the debtor cannot obtain funds from sources other than the existing creditors at a market rate for debt with similar risk characteristics. In determining whether the Company has granted a concession, the Company assesses, if it does not expect to collect all amounts due, whether the current value of the collateral will satisfy the amounts owed, whether additional collateral or guarantees from the debtor will serve as adequate compensation for other terms of the restructuring, and whether the debtor otherwise has access to funds at a market rate for debt with similar risk characteristics. Periodically, the Company will restructure a note into two separate notes (A/B structure), charging off the entire B portion of the note. The A note is structured with appropriate loan-to-value and cash flow coverage ratios that provide for a high likelihood of repayment. The A note is classified as a nonperforming note until the borrower has displayed a historical payment performance for a reasonable time prior to and subsequent to the restructuring. A period of sustained repayment for at least six months generally is required to return the note to accrual status provided that management has determined that the performance is reasonably expected to continue. The A note will be classified as a restructured note (either performing or nonperforming) through the calendar year of the restructuring that the historical payment performance has been established. Allowance for Loan Losses: The Company establishes provisions for loan losses, which are charged to the Company’s results of operations to maintain the allowance for loan losses to absorb probable incurred credit losses in the loan portfolio. In determining the level of the allowance for loan losses, the Company considers past and current loss experience, trends in classified loans, evaluations of real estate collateral, current economic conditions, volume and type of lending, adverse situations that may affect a borrower’s ability to repay a loan and the levels of nonperforming and other classified loans. The amount of the allowance is based on estimates and the ultimate losses may vary from the estimates as more information becomes available or events change. The Company provides for loan losses based on the allowance method. Accordingly, all loan losses are charged to the related allowance and all recoveries are credited to it. Additions to the allowance for loan losses are provided by charges to income based on various factors that, in our judgment, deserve current recognition in estimating probable incurred credit losses. The Company reviews the loan portfolio on an ongoing basis and makes provisions for loan losses on a quarterly basis to maintain the allowance for loan losses in accordance with GAAP. The allowance for loan losses consists of two components: • specific allowances established for any impaired residential non-owner occupied mortgage, multi-family mortgage, nonresidential real estate, construction and land, commercial, and commercial lease loans for which the recorded investment in the loan exceeds the measured value of the loan; and • general allowances for loan losses for each loan class based on historical loan loss experience; and adjustments to historical loss experience (general allowances), maintained to cover uncertainties that affect our estimate of probable incurred credit losses for each loan class. The adjustments to historical loss experience are based on our evaluation of several factors, including levels of, and trends in, past due and classified loans; levels of, and trends in, charge–offs and recoveries; trends in volume and terms of loans, including any credit concentrations in the loan portfolio; experience and ability of lending management and other relevant staff; and national and local economic trends and conditions. The Company evaluates the allowance for loan losses based upon the combined total of the specific and general components. Generally, when the loan portfolio increases, absent other factors, the allowance for loan loss methodology results in a higher dollar amount of estimated probable incurred credit losses than would be the case without the increase. Conversely, when the loan portfolio decreases, absent other factors, the allowance for loan loss methodology generally results in a lower dollar amount of estimated probable losses than would be the case without the decrease. The loss ratio used in computing the required general loan loss reserve allowance for a given class of loan consists of (i) the actual loss ratio (measured on a weighted, rolling twelve-quarter basis), (ii) the change in credit quality within the specific loan class during the period, (iii) the actual inherent risk factor assigned to the specific loan class and (iv) the actual concentration of risk factor assigned to the specific loan class (collectively, the “Specific Loan Class Risk Factors”). The Specific Loan Class Risk Factors are weighted equally in the calculation. In addition, two additional quantitative factors, the National Economic risk factor and the Local Economic risk factor, are also components of the computation but are given different weightings in their computation due to their relative applicability to the specific loan class in the context of the effect of national and local economic conditions on their risk profile and performance. Mortgage Servicing Rights : Mortgage servicing rights are recognized separately when they are acquired through sales of loans. When mortgage loans are sold, servicing rights are initially recorded at fair value and gains on sales of loans are recorded in the statement of operations. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the servicing cost per loan, the discount rate, the escrow float rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses. The Company compares the valuation model inputs and results to published industry data in order to validate the model results and assumptions. All classes of servicing assets are subsequently measured using the amortization method which requires servicing rights to be amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. Servicing assets are evaluated for impairment based upon the fair value of the rights as compared to carrying amount. Impairment is determined by stratifying rights into groupings based on predominant risk characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance for an individual grouping, to the extent that fair value is less than the carrying amount. If the Company later determines that all or a portion of the impairment no longer exists for a particular grouping, a reduction of the allowance may be recorded as an increase to income. Changes in valuation allowances are reported with amortization and impairment of servicing assets on the statement of operations. The fair values of servicing rights are subject to significant fluctuations as a result of changes in estimated and actual prepayment speeds and default rates and losses. Servicing fee income that is reported on the statement of operations as loan servicing fees is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal; or a fixed amount per loan and are recorded as income when earned. Late fees and ancillary fees related to loan servicing are not material. First mortgage loans serviced for others are not included in the accompanying consolidated statements of financial condition. The unpaid principal balances of these loans were $76.2 million and $90.7 million at December 31, 2018 and 2017 , respectively. Custodial escrow balances maintained in connection with the foregoing loan servicing activities were $1.8 million and $2.6 million at at December 31, 2018 and 2017 , respectively. Capitalized mortgage servicing rights are included in the other assets in the accompanying consolidated statements of financial condition. Servicing rights were $420,000 and $513,000 at December 31, 2018 and 2017 , respectively, with no valuation allowance at December 31, 2018 and 2017 . Other Real Estate Owned ("OREO") : Foreclosed assets are initially recorded at fair value less cost to sell when acquired, establishing a new cost basis. Physical possession of residential real estate property collateralizing a consumer mortgage loan occurs when the legal title is obtained upon completion of foreclosure or when the borrower conveys all interest in the property to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. These assets are subsequently accounted for at a lower of cost or fair value less estimated cost to sell. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating expenses, gains and losses on disposition, and changes in the valuation allowance are reported in noninterest expense as operations of other real estate owned. Premises and Equipment : Land is carried at cost. Premises and equipment are stated at cost less accumulated depreciation. Depreciation is included in noninterest expense and is computed on the straight-line method over the estimated useful lives of the assets. Useful lives are estimated to be 25 to 40 years for buildings and improvements that extend the life of the original building, ten to 20 years for routine building improvements, five to 15 years for furniture and equipment, two to five years for computer hardware and software and no greater than four years on automobiles. The cost of maintenance and repairs is charged to expense as incurred and significant repairs are capitalized. In December 2017, we agreed to a letter of intent to sell our corporate office building in Burr Ridge, Illinois. In January 2018, we executed a formal sales agreement to sell the property subject to certain contingencies exclusively in the control of the purchaser. The asset is recorded in our financial statements at December 31, 2017 as premises held-for-sale at a net cost of $5.7 million . On April 23, 2018, the Bank sold its office building. A net gain of $93,000 was recorded in the second quarter of 2018 in connection with the sale. Other Intangible Assets : Intangible assets acquired in a purchase business combination with definite useful lives are amortized over their estimated useful lives to their estimated residual values. Core deposit intangible assets (“CDI”), are recognized at the time of acquisition based on valuations prepared by independent third parties or other estimates of fair value. In preparing such valuations, variables such as deposit servicing costs, attrition rates, and market discount rates are considered. CDI assets are amortized to expense over their useful lives. Bank Owned Life Insurance: The Company has purchased life insurance policies on certain key executives. The Company owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement. Long-Term Assets : Premises and equipment, core deposit and other intangible assets, and other long-term assets are reviewed for impairment when events indicate that their carrying amount may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value. Loan Commitments and Related Financial Instruments : Financial instruments include off-balance-sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded. Income Taxes : Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Under GAAP, a deferred tax asset valuation allowance is required to be recognized if it is “more likely than not” that the deferred tax asset will not be realized. The determination of the realizability of the deferred tax assets is highly subjective and dependent upon judgment concerning management’s evaluation of both positive and negative evidence, the forecasts of future taxable income, applicable tax planning strategies, and assessments of current and future economic and business conditions. The Company considers both positive and negative evidence regarding the ultimate realizability of our deferred tax assets. Examples of positive evidence may include the existence, if any, of taxes paid in available carry-back years and the likelihood that taxable income will be generated in future periods. Examples of negative evidence may include a cumulative loss in the current year and prior two years and negative general business and economic trends. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period of the enactment date. This analysis is updated quarterly and adjusted as necessary. At December 31, 2018 , the Company had a net deferred tax asset of $6.2 million . A tax position is recognized as a benefit only if it is "more likely than not" that the tax position would be sustained in a tax examination, presuming that a tax examination will occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely to be realized on examination. For tax positions not meeting the "more likely than not" test, no tax benefit is recorded. Retirement Plans : Employee 401(k) and profit sharing plan expense is the amount of matching contributions and any annual discretionary contribution made at the discretion of the Company’s Board of Directors. Deferred compensation expense allocates the benefits over years of service. Earnings per Common Share : Basic earnings per common share is net income divided by the weighted average number of common shares outstanding during the period. ESOP shares are considered outstanding for this calculation unless unearned. Diluted earnings per common share is net income divided by the weighted average number of common shares outstanding during the period plus the dilutive effect of restricted stock shares and the additional potential shares issuable under stock options. Loss Contingencies : Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe that there are such matters that will have a material effect on the financial statements as of December 31, 2018 . Restrictions on Cash : Cash on hand or on deposit with the Federal Reserve Bank that is required to meet regulatory reserve and clearing requirements. Fair Values of Financial Instruments : Fair values of financial instruments are estimated using relevant market value information and other assumptions, as more fully disclosed in a separate note. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect the estimates. Comprehensive Income : Comprehensive income consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available-for-sale, net of tax, which are also recognized as separate components of stockholders’ equity. Transfers of Financial Assets: Transfers of financial assets are accounted for as sales when control over the assets has been relinquished. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Operating Segments: While management monitors the revenue streams of the various products and services, operations are managed and financial performance is evaluated on a Company-wide basis. Operating results are not reviewed by senior management to make resource allocation or performance decisions. Accordingly, all of the financial service operations are considered by management to be aggregated in one reportable operating segment. Reclassifications : Certain reclassifications have been made in the prior year’s financial statements to conform to the current year’s presentation. Reclassifications had no effect on prior year net income or stockholders’ equity. Adoption of New Accounting Standards In May 2014, the FASB issued an update (ASU No. 2014-09, Revenue from Contracts with Customers) creating FASB Topic 606, Revenue from Contracts with Customers. The guidance in this update affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (for example, insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides steps to follow to achieve the core principle. An entity should disclose sufficient information to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Qualitative and quantitative information is required about contracts with customers, significant judgments and changes in judgments, and assets recognized from the costs to obtain or fulfill a contract. The amendments in this update became effective for annual periods and interim periods within those annual periods beginning after December 15, 2017. Effective January 1, 2018, the Company adopted the new standard. The Company’s revenue streams that are in-scope from the update include: financed OREO sales; deposit fees, including ATM fees, overdraft fees, maintenance fees and dormancy fees; debit card fees, and trust fees. For the in-scope revenue streams, our current revenue recognition is not different than our prior revenue recognition under the update. The Company has infrequently financed an OREO sale. Our customer contracts generally do not have performance obligations and fees are assessed and collected as the transaction occurs. The Company’s fee income is not material for any individual income streams. The adoption of ASC 606 did not result in a change to the accounting for any of the in-scope revenue streams; as such, no cumulative effect adjustment was recorded. Refer to Note 16 - Revenue for Contracts with Customers for further discussion on the Company's accounting policies for revenue sources within the scope of ASC 606. In January 2016, the FASB issued an update (ASU No. 2016-01, Financial Instruments - Recognition and Measurement of Financial Assets and Liabilities). The new guidance is intended to improve the recognition and measurement of financial instruments by requiring: equity investments (other than equity method or consolidation) to be measured at fair value with changes in fair value recognized in net income; public business entities to use the exit price notion when measuring the fair value of financial instruments at amortized cost for disclosure purposes; separate presentation of financial assets and financial liabilities by measurement category and form of financial assets ( i.e., securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements; eliminating the requirement to disclose the fair value of financial instruments measured at amortized cost for organizations that are not public business entities; eliminating the requirement for non-public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is to be required to be disclosed for financial instruments measured at amortized cost on th

Earnings Per Share (Notes)

Earnings Per Share (Notes)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Amounts reported in earnings per share reflect net income available to common stockholders for the period divided by the weighted average number of shares of common stock outstanding during the period, exclusive of unearned ESOP shares and unvested restricted stock shares. Stock options and restricted stock are regarded as potential common stock and are considered in the diluted earnings per share calculations to the extent that they would have a dilutive effect if converted to common stock. For the years ended 2018 2017 Net income available to common stockholders $ 19,342 $ 9,004 Average common shares outstanding 17,434,780 18,429,018 Less: Unearned ESOP shares — (148,179 ) Unvested restricted stock shares (435 ) (940 ) Weighted average common shares outstanding 17,434,345 18,279,899 Add - Net effect of dilutive stock options and unvested restricted stock — 437 Weighted average dilutive common shares outstanding 17,434,345 18,280,336 Basic earnings per common share $ 1.11 $ 0.49 Diluted earnings per common share $ 1.11 $ 0.49

Securities (Notes)

Securities (Notes)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	The fair value of securities and the related gross unrealized gains and losses recognized in accumulated other comprehensive income is as follows: Available-for-Sale Securities Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value December 31, 2018 Certificates of deposit $ 73,507 $ — $ — $ 73,507 Municipal securities 509 — — 509 Mortgage-backed securities - residential 10,116 400 (38 ) 10,478 Collateralized mortgage obligations - residential 3,676 11 (2 ) 3,685 $ 87,808 $ 411 $ (40 ) $ 88,179 December 31, 2017 Certificates of deposit $ 75,916 $ — $ — $ 75,916 Equity mutual fund 500 — (1 ) 499 Mortgage-backed securities - residential 11,969 520 (17 ) 12,472 Collateralized mortgage obligations - residential 4,481 16 (11 ) 4,486 SBA-guaranteed loan participation certificates 10 — — 10 $ 92,876 $ 536 $ (29 ) $ 93,383 Equity Investments (1) December 31, 2018 Visa Class B shares $ — 3,427 — $ 3,427 (1) Equity investments are included in Other Assets in the Consolidated Statements of Financial Condition. Mortgage-backed securities and collateralized mortgage obligations reflected in the preceding table were issued by U.S. government-sponsored entities and agencies, Freddie Mac, Fannie Mae and Ginnie Mae, and are obligations which the government has affirmed its commitment to support. The amortized cost and fair values of securities available-for-sale at December 31, 2018 by contractual maturity are shown below. Securities not due at a single maturity date are shown separately. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. December 31, 2018 Amortized Cost Fair Value Due in one year or less $ 73,507 $ 73,507 Due after one year through five years 509 509 74,016 74,016 Mortgage-backed securities - residential 10,116 10,478 Collateralized mortgage obligations - residential 3,676 3,685 $ 87,808 $ 88,179 Investment securities available for sale with carrying amounts of $2.7 million and $3.7 million at December 31, 2018 and 2017 , respectively, were pledged as collateral on customer repurchase agreements and for other purposes as required or permitted by law. Sales of equity securities were as follows: For the years ended 2018 2017 Proceeds $ 4,059 $ — Gross gains 3,572 — Gross losses (14 ) — Securities available-for-sale with unrealized losses at December 31, 2018 and 2017 not recognized in income are as follows: Less than 12 Months 12 Months or More Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss December 31, 2018 Mortgage-backed securities - residential $ — $ — $ 904 $ (38 ) $ 904 $ (38 ) Collateralized mortgage obligations - residential — — 1,729 (2 ) 1,729 (2 ) $ — $ — $ 2,633 $ (40 ) $ 2,633 $ (40 ) December 31, 2017 Equity mutual fund $ 499 $ (1 ) $ — $ — $ 499 $ (1 ) Mortgage-backed securities - residential — — 1,149 (17 ) 1,149 (17 ) Collateralized mortgage obligations - residential — — 2,083 (11 ) 2,083 (11 ) $ 499 $ (1 ) $ 3,232 $ (28 ) $ 3,731 $ (29 ) The Company evaluates marketable investment securities with significant declines in fair value on a quarterly basis to determine whether they should be considered other-than-temporarily impaired under current accounting guidance, which generally provides that if a marketable security is in an unrealized loss position, whether due to general market conditions or industry or issuer-specific factors, the holder of the securities must assess whether the impairment is other-than-temporary. Certain residential mortgage-backed securities and collateralized mortgage obligations that the Company holds in its investment portfolio were in an unrealized loss position at December 31, 2018 , but the unrealized loss was not considered significant under the Company’s impairment testing methodology. In addition, the Company does not intend to sell these securities, and it is not likely that the Company will be required to sell the securities before their anticipated recovery occurs. The Bank, as a member of Visa USA, received 51,404 unrestricted shares of Visa, Inc. Class B common stock in connection with Visa, Inc.’s initial public offering in 2007. The retroactive responsibility plan obligates all former Visa USA members to indemnify Visa USA, in proportion to their equity interests in Visa USA, for certain litigation losses and expenses, including settlement expenses, for the lawsuits covered by the retrospective responsibility plan. Due to the restrictions that the retrospective responsibility plan imposes on the Company’s Visa, Inc. Class B shares, the Company had not recorded the Class B shares as an asset. The Bank sold 25,702 shares of Visa Class B common stock in the fourth quarter of 2018 and recored a gain of $3.6 million . For equity investments without readily determinable fair values, when an orderly transaction for the identical or similar investment of the same issuer is identified, we use the valuation techniques permitted under ASC 820 Fair Value to evaluate the observed transaction(s) and adjust the fair value of the equity investment. Based on the existing transfer restriction and the uncertainty of the outcome of the Visa litigation mentioned above, the remaining 25,702 Visa Class B shares that the Company owns as of December 31, 2018 are carried at $3.4 million in other assets. ASC 321-10 also provides guidance related to accounting for impairment of equity securities without readily determinable fair values. The qualitative assessment to determine whether impairment exists requires the use of our judgment in certain circumstances. If, after completing the qualitative assessment we conclude an equity investment without a readily determinable fair value is impaired, a loss for the difference between the equity investment’s carrying value and its fair value may be recognized as a reduction to noninterest income in the Consolidated Statements of Operations.

Loans Receivable (Notes)

Loans Receivable (Notes)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Loans Receivable	December 31, 2018 2017 One-to-four family residential real estate $ 70,371 $ 97,814 Multi-family mortgage 619,870 588,383 Nonresidential real estate 152,442 169,971 Construction and land 172 1,358 Commercial loans 187,406 152,552 Commercial leases 299,394 310,076 Consumer 1,539 1,597 1,331,194 1,321,751 Net deferred loan origination costs 1,069 1,266 Allowance for loan losses (8,470 ) (8,366 ) Loans, net $ 1,323,793 $ 1,314,651 Loan Origination/Risk Management. The Company has certain lending policies and procedures in place that are designed to maximize loan income within an acceptable level of risk. The Company reviews and approves these policies and procedures on a periodic basis. A reporting system supplements the review process by providing management with frequent reports related to loan production, loan quality, concentrations of credit, loan delinquencies and nonperforming and potential problem loans via trend and risk rating migration. The Company requires title insurance insuring the priority of our lien on real estate collateral, fire and extended coverage casualty insurance, and, if appropriate, flood insurance, in order to protect our security interest in the underlying real property collateral. The majority of the loans the Company originates are commercial-related loans, such as multi-family, nonresidential real estate, commercial, construction and land loans, and commercial leases. In addition, we originated one-to-four family residential mortgage loans and consumer loans until December 31, 2017. We also occasionally purchase and sell loan participations. The following briefly describes our principal loan products. The Company originates real estate loans principally secured by first liens both non-owner occupied and owner occupied commercial real estate. The non-owner occupied commercial real estate properties are predominantly multi-family apartment buildings, office buildings, light industrial buildings, shopping centers and mixed-use developments and, to a much lesser extent, more specialized properties such as nursing homes and other healthcare facilities. Multi-family mortgage loans generally are secured by multi-family rental properties such as apartment buildings, including subsidized apartment units. In general, loan amounts range between $500,000 and $5.0 million at December 31, 2018 . Approximately 55.0% of the collateral is located outside of our primary market area; however, we do not have a concentration in any single market in excess of 25% of our loan portfolio outside of our primary market area. In underwriting multi-family mortgage loans, the Company considers a number of factors, which include the projected net cash flow to the loan’s debt service requirement (generally requiring a minimum ratio of 120% ), the age and condition of the collateral, the financial resources and income level of the borrower, the borrower’s experience in owning or managing similar properties and, proximity to diverse employment opportunities. Multi-family mortgage loans are generally originated in amounts up to 80% of the appraised value of the property securing the loan. Personal guarantees are usually obtained on multi-family mortgage loans if the borrower/property owner is a legal entity. Loans secured by multi-family mortgages generally involve a greater degree of credit risk than one-to-four family residential mortgage loans and carry larger loan balances. This increased credit risk is a result of several factors, including the concentration of principal in a limited number of loans and borrowers, the effects of general economic conditions on income producing properties, and the increased difficulty of evaluating and monitoring these types of loans. Furthermore, the repayment of loans secured by multi-family mortgages typically depends upon the successful operation of the related real estate property. If the cash flow from the project is reduced below acceptable thresholds, the borrower’s ability to repay the loan may be impaired. The Company emphasizes nonresidential real estate loans with initial principal balances between $500,000 and $5.0 million . Substantially all of our nonresidential real estate loans are secured by properties located in our primary market area. The Company’s nonresidential real estate loans are generally written as three - or five -year adjustable-rate mortgages or mortgages with balloon maturities of three or five years. Amortization on these loans is typically based on 20 - to 30 -year schedules. The Company also originates some 15 -year fixed-rate, fully amortizing loans. In the underwriting of nonresidential real estate loans, the Company generally lends up to 80% of the property’s appraised value. Decisions to lend are based on the economic viability of the property as the primary source of repayment and the creditworthiness of the borrower. In evaluating a proposed commercial real estate loan, we emphasize the ratio of the property’s projected net cash flow to the loan’s debt service requirement (generally requiring a minimum ratio of 120% ), computed after deduction for a vacancy factor and property expenses we deem appropriate. Personal guarantees are usually pursued and obtained from nonresidential real estate borrowers. Nonresidential real estate loans generally carry higher interest rates and have shorter terms than one-to-four family residential mortgage loans. Nonresidential real estate loans, however, entail significant additional credit risks compared to one-to-four family residential mortgage loans, as they typically involve larger loan balances concentrated with single borrowers or groups of related borrowers. In addition, the payment of loans secured by income-producing properties typically depends on the successful operation of the related real estate project and thus may be subject to a greater extent to adverse conditions in the real estate market and in the general economy. The Company makes various types of secured and unsecured commercial loans to customers in our market area for the purpose of financing equipment acquisition, expansion, working capital and other general business purposes. The terms of these loans generally range from less than one year to five years. The loans are either negotiated on a fixed-rate basis or carry adjustable interest rates indexed to (i) a lending rate that is determined internally, or (ii) a short-term market rate index. Commercial credit decisions are based upon our assessment of the borrower’s cash flow, proposed collateral, business and credit history and any additional positive or negative credit risk factors. The Company determines the borrower’s ability to repay in accordance with the proposed terms of the loans and we assess the risks involved. An evaluation is made of the borrower to determine character and capacity to manage. Personal guarantees of the principals are pursued and usually obtained. In addition to evaluating the loan borrower’s financial statements, we consider the adequacy of the primary and secondary sources of repayment for the loan. Independent reports of the borrower’s credit history supplement our analysis of the borrower’s creditworthiness and at times are supplemented with inquiries to other banks and trade investigations. Moreover, certain assets listed on personal financial statements are verified. Proposed collateral for a secured transaction also is analyzed to determine its marketability. Commercial business loans generally have higher interest rates than residential loans of like duration because they have a higher risk of default since their repayment generally depends on the successful operation of the borrower’s business and the sufficiency of any collateral. Pricing of commercial loans is based primarily on the credit risk of the borrower, with due consideration given to borrowers with appropriate deposit relationships. The Company also lends money to small and mid-size leasing companies for equipment financing leases. Generally, commercial leases are secured by an assignment by the leasing company of the lease payments and by a secured interest in the equipment being leased. In most cases, the lessee acknowledges our security interest in the leased equipment and agrees to send lease payments directly to us. Consequently, the Company underwrites lease loans by examining the creditworthiness of the lessee rather than the lessor. Lease loans generally are non-recourse to the leasing company. The Company’s commercial leases are secured primarily by technology equipment, medical equipment, material handling equipment and other capital equipment. Lessees tend to be publicly-traded companies with investment-grade rated debt or companies that have not issued public debt and therefore do not have a public debt rating. Commercial leases to these entities have a maximum outstanding credit exposure of $20.0 million to any single entity. If the lessee does not have a public debt rating, they are subject to the same internal credit analysis as any other customer. Typically, commercial leases to these lessees have a maximum maturity of five years and a maximum outstanding credit exposure of $10.0 million to any single entity. In addition, the Company will originate commercial leases to lessees with below investment-grade public debt ratings and have a maximum outstanding credit exposure of $10.0 million to any single entity. Lease loans are almost always fully amortizing, with fixed interest rates. Although the Company does not actively originate construction and land loans presently, construction and land loans generally consist of land acquisition loans to help finance the purchase of land intended for further development, including single-family homes, multi-family housing and commercial income property, development loans to builders in our market area to finance improvements to real estate, consisting mostly of single-family subdivisions, typically to finance the cost of utilities, roads, sewers and other development costs. Until December 31, 2017, the Company offered conforming and non-conforming, fixed-rate and adjustable-rate residential mortgage loans with maturities of up to 30 years and maximum loan amounts generally of up to $2.5 million . One-to-four family residential mortgage loans were generally underwritten according to Fannie Mae guidelines, and loans that conformed to such guidelines are referred to as “conforming loans.” The Company generally originated both fixed- and adjustable-rate loans in amounts up to the maximum conforming loan limits as established by Fannie Mae, which is currently $424,100 for single-family homes. Private mortgage insurance is required for first mortgage loans with loan-to-value ratios in excess of 80% . The Company also occasionally originated loans above conforming limits, sometimes referred to as “jumbo loans,” that were underwritten to the credit standards of Fannie Mae. These loans were generally eligible for sale to various firms that specialize in the purchase of such non-conforming loans. The ability of the Company’s borrowers to repay their loans, and the value of the collateral securing such loans, could be adversely impacted by economic weakness in its local markets as a result of unemployment, declining real estate values, or increased residential, office, industrial and retail shopping vacancies due to changes in business conditions. This not only could result in the Company experiencing charge-offs and/or nonperforming assets, but also could necessitate an increase in the provision for loan losses. These events, if they were to recur, would have an adverse impact on the Company’s results of operations and its capital. The following tables present the balance in the allowance for loan losses and the loans receivable by portfolio segment and based on impairment method: Allowance for loan losses Loan Balances Individually evaluated for impairment Collectively evaluated for impairment Total Individually evaluated for impairment Collectively evaluated for impairment Total December 31, 2018 One-to-four family residential real estate $ — $ 699 $ 699 $ 2,218 $ 68,153 $ 70,371 Multi-family mortgage — 3,991 3,991 653 619,217 619,870 Nonresidential real estate 27 1,449 1,476 270 152,172 152,442 Construction and land — 4 4 — 172 172 Commercial loans — 1,517 1,517 — 187,406 187,406 Commercial leases — 755 755 — 299,394 299,394 Consumer — 28 28 — 1,539 1,539 $ 27 $ 8,443 $ 8,470 $ 3,141 $ 1,328,053 1,331,194 Net deferred loan origination costs 1,069 Allowance for loan losses (8,470 ) Loans, net $ 1,323,793 Allowance for loan losses Loan Balances Individually evaluated for impairment Collectively evaluated for impairment Total Individually evaluated for impairment Collectively evaluated for impairment Total December 31, 2017 One-to-four family residential real estate $ — $ 850 $ 850 $ 4,265 $ 93,549 $ 97,814 Multi-family mortgage — 3,849 3,849 949 587,434 588,383 Nonresidential real estate — 1,605 1,605 — 169,971 169,971 Construction and land — 32 32 — 1,358 1,358 Commercial loans — 1,357 1,357 — 152,552 152,552 Commercial leases — 655 655 — 310,076 310,076 Consumer — 18 18 — 1,597 1,597 $ — $ 8,366 $ 8,366 $ 5,214 $ 1,316,537 1,321,751 Net deferred loan origination costs 1,266 Allowance for loan losses (8,366 ) Loans, net $ 1,314,651 Activity in the allowance for loan losses is as follows: For the years ended 2018 2017 Beginning balance $ 8,366 $ 8,127 Loans charged off: One-to-four family residential real estate (231 ) (318 ) Multi-family mortgage (35 ) (10 ) Nonresidential real estate (93 ) (165 ) Commercial loans (140 ) — Consumer (19 ) (10 ) (518 ) (503 ) Recoveries: One-to-four family residential real estate 206 145 Multi-family mortgage 34 70 Nonresidential real estate — 17 Construction and land 2 — Commercial loans 229 594 Commercial leases 5 2 Consumer 1 1 477 829 Net recoveries (charge-off) (41 ) 326 Provision for (recovery of) loan losses 145 (87 ) Ending balance $ 8,470 $ 8,366 Impaired loans Several of the following disclosures are presented by “recorded investment,” which the FASB defines as “the amount of the investment in a loan, which is not net of a valuation allowance, but which does reflect any direct write-down of the investment.” The following represents the components of recorded investment: Loan principal balance Less unapplied payments Plus negative unapplied balance Less escrow balance Plus negative escrow balance Plus unamortized net deferred loan costs Less unamortized net deferred loan fees Plus unamortized premium Less unamortized discount Less previous charge-offs Plus recorded accrued interest Less reserve for uncollected interest = Recorded investment The following tables present loans individually evaluated for impairment by class of loans: Loan Balance Recorded Investment Partial Charge-off Allowance for Loan Losses Allocated Average Investment in Impaired Loans Interest Income Recognized December 31, 2018 With no related allowance recorded One-to-four family residential real estate $ 2,751 $ 2,155 $ 575 $ — $ 3,274 $ 41 One-to-four family residential real estate - non-owner occupied 86 46 43 — 95 — Multi-family mortgage 654 653 — — 795 39 3,491 2,854 618 — 4,164 80 With an allowance recorded - Nonresidential real estate 356 270 93 27 21 — $ 3,847 $ 3,124 $ 711 $ 27 $ 4,185 $ 80 Loan Balance Recorded Investment Partial Charge-off Allowance for Loan Losses Allocated Average Investment in Impaired Loans Interest Income Recognized December 31, 2017 With no related allowance recorded One-to-four family residential real estate $ 5,049 $ 4,248 $ 806 $ — $ 4,212 $ 197 Multi-family mortgage 958 948 — — 847 41 $ 6,007 $ 5,196 $ 806 $ — $ 5,059 $ 238 Nonaccrual loans The following tables present the recorded investment in nonaccrual and loans 90 days or more past due still on accrual by class of loans: Loan Balance Recorded Investment Loans Past Due Over 90 Days, still accruing December 31, 2018 One-to-four family residential real estate $ 2,167 $ 1,162 $ — One-to-four family residential real estate – non owner occupied 270 78 — Nonresidential real estate 356 270 — $ 2,793 $ 1,510 $ — December 31, 2017 One-to-four family residential real estate $ 3,413 $ 1,918 $ — One-to-four family residential real estate – non owner occupied 308 109 — Multi-family mortgage 376 363 — $ 4,097 $ 2,390 $ — Nonaccrual loans and impaired loans are defined differently. Some loans may be included in both categories, and some may only be included in one category. Nonaccrual loans include both smaller balance homogeneous loans that are collectively evaluated for impairment and individually classified impaired loans. The Company’s reserve for uncollected loan interest was $38,000 and $103,000 at December 31, 2018 and 2017 , respectively. When a loan is on non-accrual status and the ultimate collectability of the total principal of an impaired loan is in doubt, all payments are applied to principal under the cost recovery method. Alternatively, when a loan is on non-accrual status but there is doubt concerning only the ultimate collectability of interest, contractual interest is credited to interest income only when received, under the cash basis method pursuant to the provisions of FASB ASC 310–10, as applicable. In all cases, the average balances are calculated based on the month–end balances of the financing receivables within the period reported pursuant to the provisions of FASB ASC 310–10, as applicable. Past Due Loans The following tables present the aging of the recorded investment in past due loans at December 31, 2018 by class of loans: 30-59 Days Past Due 60-89 Days Past Due Greater Than 89 Days Past Due Total Past Due Loans Not Past Due Total One-to-four family residential real estate $ 1,380 $ 637 $ 1,162 $ 3,179 $ 53,820 $ 56,999 One-to-four family residential real estate - non-owner occupied 387 10 78 475 12,460 12,935 Multi-family mortgage - Illinois 458 — — 458 275,283 275,741 Multi-family mortgage - Other — — — — 340,470 340,470 Nonresidential real estate — 270 — 270 149,271 149,541 Construction — — — — — — Land — — — — 169 169 Commercial loans: Regional Commercial Banking — — — — 39,712 39,712 Health Care — — — — 85,418 85,418 Direct Commercial Lessor — — — — 62,719 62,719 Commercial leases: — Investment-grade 505 — — 505 166,713 167,218 Other — — — — 133,958 133,958 Consumer 40 4 — 44 1,508 1,552 Total $ 2,770 $ 921 $ 1,240 $ 4,931 $ 1,321,501 $ 1,326,432 The following tables present the aging of the recorded investment in past due loans as December 31, 2017 by class of loans: 30-59 Days Past Due 60-89 Days Past Due Greater Than 89 Days Past Due Total Past Due Loans Not Past Due Total One-to-four family residential real estate $ 86 $ 99 $ 1,801 $ 1,986 $ 74,216 $ 76,202 One-to-four family residential real estate - non-owner occupied 10 3 86 99 20,944 21,043 Multi-family mortgage - Illinois 172 — 364 536 287,171 287,707 Multi-family mortgage - Other — — — — 296,440 296,440 Nonresidential real estate 608 — — 608 166,071 166,679 Construction — — — — 1,103 1,103 Land — — — — 259 259 Commercial loans: Regional Commercial Banking — — — — 40,935 40,935 Health Care — — — — 71,738 71,738 Direct Commercial Lessor — — — — 40,237 40,237 Commercial leases: — Investment-grade 934 — — 934 207,747 208,681 Other 288 — — 288 102,873 103,161 Consumer — — — — 1,605 1,605 $ 2,098 $ 102 $ 2,251 $ 4,451 $ 1,311,339 $ 1,315,790 Troubled Debt Restructurings The Company evaluates loan extensions or modifications in accordance with FASB ASC 310–40 with respect to the classification of the loan as a TDR. In general, if the Company grants a loan extension or modification to a borrower for other than an insignificant period of time that includes a below–market interest rate, principal forgiveness, payment forbearance or other concession intended to minimize the economic loss to the Company, the loan extension or loan modification is classified as a TDR. In cases where borrowers are granted new terms that provide for a reduction of either interest or principal then due and payable, management measures any impairment on the restructured loan in the same manner as for impaired loans as noted above. The Company had $17,000 of TDRs at December 31, 2018 and 2017 , with no specific valuation reserves allocated at December 31, 2018 and 2017 . The Company had no outstanding commitments to borrowers whose loans are classified as TDRs at either date. The following table presents loans classified as TDRs: December 31, 2018 2017 One-to-four family residential real estate - Nonaccrual $ 17 $ 17 During the years ending December 31, 2018 and 2017 , there were no loans modified and classified as TDRs. A loan is considered to be in payment default once it is 90 days contractually past due under the modified terms. To determine whether a borrower is experiencing financial difficulty, an evaluation is performed of the probability that the borrower will be in payment default on any of its debt in the foreseeable future without the modification. This evaluation is performed under the Company’s internal underwriting policy. Credit Quality Indicators: The Company categorizes loans into risk categories based on relevant information about the ability of borrowers to service their debt, including current financial information, historical payment experience, credit documentation, public information, and current economic trends, among other factors. The Company analyzes loans individually by classifying the loans based on credit risk. This analysis includes non-homogeneous loans, such as commercial and commercial real estate loans. This analysis is performed on a monthly basis. The Company uses the following definitions for risk ratings: Special Mention. A Special Mention asset has potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the institution’s credit position at some future date. Special Mention assets are not adversely classified and do not expose an institution to sufficient risk to warrant adverse classification. Substandard. Loans categorized as substandard continue to accrue interest, but exhibit a well-defined weakness or weaknesses that may jeopardize the liquidation of the debt. The loans continue to accrue interest because they are well secured and collection of principal and interest is expected within a reasonable time. The risk rating guidance published by the Office of the Comptroller of the Currency clarifies that a loan with a well-defined weakness does not have to present a probability of default for the loan to be rated Substandard, and that an individual loan’s loss potential does not have to be distinct for the loan to be rated Substandard. Nonaccrual. An asset classified Nonaccrual has all the weaknesses inherent in one classified substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. The loans were placed on nonaccrual status. Loans not meeting the criteria above that are analyzed individually as part of the above described process are considered “Pass” rated loans. As of December 31, 2018 , and based on the most recent analysis performed, the risk category of loans by class of loans is as follows: Pass Special Mention Substandard Nonaccrual Total One-to-four family residential real estate $ 55,353 $ 495 $ 328 $ 993 $ 57,169 One-to-four family residential real estate - non-owner occupied 12,911 — 37 254 13,202 Multi-family mortgage - Illinois 279,021 — 216 — 279,237 Multi-family mortgage - Other 340,633 — — — 340,633 Nonresidential real estate 151,793 281 98 270 152,442 Construction — — — — — Land 172 — — — 172 Commercial loans: Regional commercial banking 34,764 4,810 — — 39,574 Health care 85,001 — 342 — 85,343 Direct commercial lessor 62,489 — — — 62,489 Commercial leases: Investment-grade 165,508 701 — — 166,209 Other 133,185 — — — 133,185 Consumer 1,529 3 7 — 1,539 $ 1,322,359 $ 6,290 $ 1,028 $ 1,517 $ 1,331,194 As of December 31, 2017 , and based on the most recent analysis performed, the risk category of loans by class of loans is as follows: Pass Special Mention Substandard Nonaccrual Total One-to-four family residential real estate $ 74,437 $ — $ 255 $ 1,914 $ 76,606 One-to-four family residential real estate - non-owner occupied 21,059 — 40 109 21,208 Multi-family mortgage - Illinois 290,765 — 225 368 291,358 Multi-family mortgage - Other 297,025 — — — 297,025 Nonresidential real estate 169,817 — 154 — 169,971 Construction 1,099 — — — 1,099 Land 259 — — — 259 Commercial loans: Regional commercial banking 36,373 4,528 — — 40,901 Health care 69,480 — 2,248 — 71,728 Direct commercial lessor 39,923 — — — 39,923 Commercial leases: Investment-grade 207,460 — — — 207,460 Other 102,616 — — — 102,616 Consumer 1,597 — — — 1,597 $ 1,311,910 $ 4,528 $ 2,922 $ 2,391 $ 1,321,751

Other Real Estate (Notes)

Other Real Estate (Notes)	12 Months Ended
	Dec. 31, 2018
Other Real Estate Owned [Abstract]
Other Real Estate Owned	Real estate that is acquired through foreclosure or a deed in lieu of foreclosure is classified as OREO until it is sold. When real estate is acquired through foreclosure or by deed in lieu of foreclosure, it is recorded at its fair value, less the estimated costs of disposal. If the fair value of the property is less than the loan balance, the difference is charged against the allowance for loan losses. The following represents the roll forward of OREO and the composition of OREO properties. At and For the Years Ended December 31, 2018 2017 Beginning balance $ 2,351 $ 3,895 New foreclosed properties 1,482 2,766 Valuation adjustments (27 ) (333 ) Sales (2,580 ) (3,977 ) Ending balance $ 1,226 $ 2,351 December 31, 2018 December 31, 2017 Balance Valuation Allowance Net OREO Balance Balance Valuation Allowance Net OREO Balance One–to–four family residential $ 875 $ — $ 875 $ 836 $ (9 ) $ 827 Multi-family mortgage 276 — 276 — — — Nonresidential real estate 74 — 74 1,772 (252 ) 1,520 Land 24 (23 ) 1 48 (44 ) 4 $ 1,249 $ (23 ) $ 1,226 $ 2,656 $ (305 ) $ 2,351 Activity in the valuation allowance is as follows: At and For the Years Ended December 31, 2018 2017 Beginning of year $ 305 $ 449 Additions charged to expense 27 333 Reductions from sales of other real estate owned (309 ) (477 ) End of year $ 23 $ 305 At December 31, 2018 , the balance of OREO includes no foreclosed residential real estate properties recorded as a result of obtaining physical possession of the property without title. At December 31, 2017 the balance of OREO included $352,000 foreclosed residential real estate properties recorded as a result of obtaining physical possession of the property without title. At December 31, 2018 and 2017 , the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process was $349,000 and $926,000 , respectively.

Premises and Equipment (Notes)

Premises and Equipment (Notes)	12 Months Ended
	Dec. 31, 2018
Property, Plant, Equipment And Leases [Abstract]
Premises and Equipment	Year-end premises and equipment are as follows: December 31, 2018 2017 Land and land improvements $ 12,359 $ 12,265 Buildings and improvements 30,602 29,556 Furniture and equipment 10,039 9,678 Computer equipment 4,232 3,983 57,232 55,482 Accumulated depreciation (32,027 ) (30,626 ) $ 25,205 $ 24,856 Depreciation of premises and equipment was $1.5 million and $2.0 million for the years ended December 31, 2018 and 2017 , respectively. In December 2017, we agreed to a letter of intent to sell our corporate office building located at 15W060 North Frontage Road, Burr Ridge, Illinois. The asset was recorded in our financial statements at December 31, 2017 as premises held-for-sale at a net cost of $5.7 million . On April 23, 2018, the Bank sold its office building. A net gain of $93,000 was recorded in the second quarter of 2018 in connection with the sale. The Company leases the corporate office and certain branch facilities under non-cancelable operating lease agreements expiring in various years through 2032. Rent expense, net of sublease income, for facilities was $958,000 and $477,000 in 2018 and 2017 , respectively, excluding taxes, insurance, and maintenance. The projected minimum rental expense under existing leases, not including taxes, insurance, and maintenance, as of December 31, 2018 is as follows: 2019 $ 927 2020 894 2021 913 2022 952 2023 939 Thereafter 3,250 $ 7,875

Core Deposit Intangible (Notes)

Core Deposit Intangible (Notes)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Core Deposit Intangible	The following table presents the changes in the carrying amount of core deposit intangible, gross carrying amount, accumulated amortization, and net book value: December 31, 2018 2017 Balance at the beginning of the year $ 782 $ 1,305 Amortization (496 ) (523 ) Additions — — Net Carrying Value $ 286 $ 782 Gross carrying amount $ 5,932 $ 5,932 Accumulated amortization (5,646 ) (5,150 ) Net Carrying Value $ 286 $ 782 Aggregate amortization expense was $496,000 , $523,000 and $550,000 for 2018 , 2017 and 2016 , respectively. Estimated amortization expense for each of the next five years is as follows: 2019 $ 184 2020 61 2021 34 2022 7 2023 —

Deposits (Notes)

Deposits (Notes)	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Deposits	Composition of deposits is as follows: December 31, 2018 2017 Noninterest-bearing demand deposits $ 230,041 $ 234,354 Interest-bearing NOW accounts 275,830 289,657 Money market accounts 255,951 299,581 Savings deposits 152,334 160,501 Certificates of deposit 438,328 355,958 $ 1,352,484 $ 1,340,051 Time deposits that meet or exceed the FDIC Insurance limit of $250,000 were $81.5 million and $50.3 million at December 31, 2018 and 2017 , respectively. Certificates of deposits include wholesale certificates totaling $106.3 million and $131.6 million at December 31, 2018 and 2017 , respectively. Of those certificates, $69.9 million and $92.2 million are brokered at December 31, 2018 and 2017 , respectively. Scheduled maturities of certificates of deposit for the next five years are as follows: 2019 $ 290,219 2020 125,991 2021 17,359 2022 3,231 2023 1,528

Securities Sold Under Agreement

Securities Sold Under Agreement to Repurchase Securities Sold Under Agreement to Repurchase	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Securities Sold Under Agreement to Repurchase	SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE Securities sold under agreements to repurchase are shown below. Overnight and Continuous Up to 30 days 30 - 90 days Greater Than 90 days Total December 31, 2018 Repurchase agreements and repurchase-to-maturity transactions $ 1,049 $ — $ — $ — $ 1,049 Gross amount of recognized liabilities for repurchase agreements in Statement of Financial Condition $ 1,049 December 31, 2017 Repurchase agreements and repurchase-to-maturity transactions $ 768 $ — $ — $ — $ 768 Gross amount of recognized liabilities for repurchase agreements in Statement of Financial Condition $ 768 Securities sold under agreements to repurchase were secured by mortgage-backed securities with a carrying amount of $2.7 million and $3.7 million at December 31, 2018 and 2017 , respectively. Also included in total borrowings were advances from the FHLB of $20.0 million and $60.0 million at December 31, 2018 and 2017 , respectively. As the securities’ values fluctuate due to market conditions, the Company has no control over the market value. The Company is obligated to promptly transfer additional securities if the market value of the securities falls below the repurchase price, per the agreement.

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances (Notes)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Federal Home Loan Bank Advances	FEDERAL HOME LOAN BANK ADVANCES At year-end, advances from the FHLB were as follows: December 31, 2018 2017 Contractual Rate Amount Contractual Rate Amount Fixed-rate advance from FHLB, due within 1 year 2.51 % $ 20,000 1.34 % $ 60,000 The Company maintains a collateral pledge agreement covering secured advances whereby the Company has agreed to keep on hand, free of all other pledges, liens, and encumbrances, specifically identified whole first mortgages on improved residential property not more than 90-days delinquent to secure advances from the FHLB. All of the Bank’s FHLB common stock is pledged as additional collateral for these advances. At December 31, 2018 , $46.9 million and $358.9 million of first mortgage and multi-family mortgage loans, respectively, collateralized potential advances. At December 31, 2018 , we had the ability to borrow an additional $311.8 million under our credit facilities with the FHLB. The Company also had available pre-approved overnight federal funds borrowing. At December 31, 2018 and 2017 , there was no outstanding balance on these lines.

Income Taxes (Notes)

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The income tax expense is as follows: For the years ended 2018 2017 Current expense (benefit) $ 378 $ (2,658 ) Deferred expense 6,328 7,361 Expense due to enactment of federal tax reform — 2,487 Total income tax expense $ 6,706 $ 7,190 A reconciliation of the provision for income taxes computed at the statutory federal corporate tax rate of 21% and 34% for 2018 and 2017 , respectively, to the income tax expense in the consolidated statements of operations follows: For the years ended 2018 2017 Expense computed at the statutory federal tax rate $ 5,470 $ 5,506 State taxes and other, net 1,564 (204 ) Bank owned life insurance (328 ) (90 ) ESOP/Share based compensation — (509 ) Expense due to enactment of federal tax reform — 2,487 $ 6,706 $ 7,190 Effective income tax rate 25.74 % 44.77 % Retained earnings at December 31, 2018 and 2017 include $14.9 million for which no deferred federal income tax liability has been recorded. This amount represents an allocation of income to bad debt deductions for tax purposes alone. The net deferred tax asset is as follows: December 31, 2018 2017 Gross Deferred tax assets Allowance for loan losses $ 2,279 $ 2,258 Alternative minimum tax, general business credit and net operating loss carryforwards 6,669 11,864 Tax deductible goodwill and core deposit intangible 561 801 Other 1,256 1,395 10,765 16,318 Gross Deferred tax liabilities Net deferred loan origination costs (1,186 ) (1,255 ) Purchase accounting adjustments (1,673 ) (1,744 ) Other (649 ) (619 ) Unrealized gain on securities (1,022 ) (137 ) (4,530 ) (3,755 ) $ 6,235 $ 12,563 As of December 31, 2018 and 2017 , the Company’s net deferred tax asset (“DTA”) was $6.2 million and $12.6 million , respectively. On December 22, 2017, H.R. 1, commonly known as the Tax Cuts and Job Act (the "Act"), was signed into law. Among other things, the Act reduces our corporate federal tax rate from 34% to 21% effective January 1, 2018. As a result, we were required to re-measure, through income tax expense our deferred tax assets and liabilities using the enacted rate at which we expect them to be recovered or settled. The re-measurement of our net deferred tax asset resulted in additional tax expense of $2.5 million for the year ended December 31, 2017 . A DTA valuation allowance is required under ASC 740 when the realization of a DTA is assessed and the assessment indicates that it is “more likely than not” ( i.e., more than 50% likely) that all or a portion of the DTA will not be realized. All available evidence, both positive and negative must be considered to determine whether, based on the weight of that evidence, a valuation allowance against the net DTA is required. Objectively verifiable evidence is assigned greater weight than evidence that is not objectively verifiable. The valuation allowance is analyzed quarterly for changes affecting the DTA. The Company’s ability to realize the DTA is dependent upon the generation of future taxable income during the periods in which the tax attributes underlying the DTA become deductible. The amount of the DTA that will ultimately be realized will be impacted by the Company’s future taxable income, any changes to the many variables that could impact future taxable income and the then applicable corporate tax rate. As of December 31, 2018 and 2017 , management determined that it is more likely than not that the Company will be able to utilize the entire DTA. At December 31, 2018 , the Company had a federal net operating loss carryforward of $1.2 million , which will begin to expire in 2033 and a federal tax credit carryforward of $1.3 million , which will begin to expire in 2022. In addition, the Company had a $3.1 million alternative minimum tax credit carryforward that can be carried forward indefinitely, which is now carried as tax receivables since under new federal law of the Company expects to recover the entire amount by the end of 2021 via reduction of regular tax liability or refund. In addition, at December 31, 2018 , the Company had a federal net operating loss carryforward of $7.5 million relating to its acquisition of Downers Grove National Bank, which is subject to utilization limitations under Section 382 of the Internal Revenue Code, and will begin to expire in 2030, and $225,000 of alternative minimum tax credit carryforward that does not expire and is subject to utilization limitations under Section 382 of the Internal Revenue Code. At December 31, 2018 , the Company had a state net operating loss carryforward for the State of Illinois of $58.5 million , which will begin to expire in 2022. At December 31, 2017, the Company early adopted ASU 2018-02 and reclassified out of retained earnings and into accumulated other comprehensive income $60,000 of tax (benefit) that was recorded to income tax expense at December 22, 2017 due to re-measuring to 21% deferred taxes on available for sale securities. Unrecognized Tax Benefits A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: December 31, 2018 2017 Beginning of year $ 129 $ 57 Additions based on tax positions related to the current year 85 60 Additions for tax positions of prior years 4 12 Reductions due to the statute of limitations and reductions for tax positions of prior years (20 ) — End of year $ 198 $ 129 The Company does not expect the total amount of unrecognized tax benefits to significantly increase or decrease in the next twelve months. The Company recognizes interest and/or penalties related to income tax matters in income tax expense. At December 31, 2018 and 2017 , the Company has immaterial amounts accrued for potential interest and penalties. The Company and its subsidiary are subject to U.S. federal income tax as well as income tax of the various states where the Company does business. The Company is no longer subject to examination by the federal taxing authorities for years before 2015 and the Illinois taxing authorities for years before 2015.

Regulatory Matters (Notes)

Regulatory Matters (Notes)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Regulatory Matters	REGULATORY MATTERS The Bank and the Company were subject to regulatory capital requirements administered by the federal banking agencies in 2017. In August 2018, the Federal Reserve Board issued an interim final ruling that holding companies with assets less than $3 billion are not subject to minimum capital requirements. The capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve the quantitative measurement of assets, liabilities, and certain off-balance-sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators. The failure to meet minimum capital requirements can result in regulatory actions. The final rules implementing Basel Committee on Banking Supervision's capital guidelines for U.S. banks (Basel III rules) became effective for the Company on January 1, 2015, with full compliance with all of the requirements being phased in over a multi-year schedule, and fully phased in by January 1, 2019. The net unrealized gain or loss on available for sale securities is not included in computing regulatory capital. Prompt corrective action regulations provide five classifications: well-capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized, although these terms are not used to represent overall financial condition. If only adequately capitalized, regulatory approval is required to accept brokered deposits. If undercapitalized, capital distributions are limited, as is asset growth and expansion, and capital restoration plans are required. As of December 31, 2018 and 2017 , the OCC categorized the Bank as well–capitalized under the regulatory framework for prompt corrective action. There are no conditions or events since those notifications that management believes have changed the institution’s well–capitalized status. Actual and required capital amounts and ratios were: Actual Required for Capital Adequacy Purposes To be Well-Capitalized under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio December 31, 2018 Total capital (to risk-weighted assets): BankFinancial, NA 178,664 15.30 93,430 8.00 $ 116,787 10.00 % Tier 1 (core) capital (to risk-weighted assets): BankFinancial, NA 170,194 14.57 70,072 6.00 93,430 8.00 Common Tier 1 (CET1) BankFinancial, NA 170,194 14.57 52,554 4.50 75,912 6.50 Tier 1 (core) capital (to adjusted average total assets): BankFinancial, NA 170,194 11.03 61,721 4.00 77,151 5.00 December 31, 2017 Total capital (to risk-weighted assets): Consolidated $ 195,371 17.06 % $ 91,590 8.00 % N/A N/A BankFinancial, NA 188,582 16.48 91,572 8.00 $ 114,466 10.00 % Tier 1 (core) capital (to risk-weighted assets): Consolidated 187,005 16.33 68,692 6.00 N/A N/A BankFinancial, NA 180,216 15.74 68,679 6.00 91,572 8.00 Common Tier 1 (CET1) Consolidated 187,005 16.33 51,519 4.50 N/A N/A BankFinancial, NA 180,216 15.74 51,509 4.50 74,403 6.50 Tier 1 (core) capital (to adjusted average total assets): Consolidated 187,005 11.49 65,085 4.00 N/A N/A BankFinancial, NA 180,216 11.08 65,045 4.00 81,307 5.00 The Company and the Bank have each adopted Regulatory Capital Plans that require the Bank to maintain a Tier 1 leverage ratio of at least 7.5% and a total risk-based capital ratio of at least 10.5% (including the Capital Conservation Buffer ("CCB")). The minimum capital ratios set forth in the Regulatory Capital Plans will be increased and other minimum capital requirements will be established if and as necessary. In accordance with the Regulatory Capital Plans, neither the Company nor the Bank will pursue any acquisition or growth opportunity, declare any dividend or conduct any stock repurchase that would cause the Bank's total risk-based capital ratio and/or its Tier 1 leverage ratio to fall below the established minimum capital levels or the capital levels required for capital adequacy plus the CCB. The minimum CCB in 2017 is 1.25% and will increase 0.625% annually through 2019 to 2.5%. In addition, the Company will continue to maintain its ability to serve as a source of financial strength to the Bank by holding at least $5.0 million of cash or liquid assets for that purpose. As of December 31, 2018 , the Bank and the Company were well-capitalized, with all capital ratios exceeding the well-capitalized requirement. There are no conditions or events that management believes have changed the Bank’s prompt corrective action capitalization category. The Bank is subject to regulatory restrictions on the amount of dividends it may declare and pay to the Company without prior regulatory approval, and to regulatory notification requirements for dividends that do not require prior regulatory approval.

Employee Benefit Plans (Notes)

Employee Benefit Plans (Notes)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Employee Stock Ownership Plan . On March 29, 2017, the ESOP was terminated and the ESOP repaid all amounts owing under the ESOP’s Term Loan Agreement with the Company (the “Share Acquisition Loan”). The ESOP repaid the Share Acquisition Loan by transferring 753,490 unallocated shares of the Company’s common stock to the Company in exchange for the full satisfaction of the Share Acquisition Loan, using the valuation method provided for in the ESOP. A total of 78,362 unallocated shares remained in the ESOP after the Share Acquisition Loan was repaid, and these shares were released and were allocated to the accounts of eligible ESOP participants who were actively employed by the Bank as of March 29, 2017, based on their account balances. These transactions resulted in the recording of one-time, non-cash, non-tax deductible equity compensation expense of $1.1 million in the first quarter of 2017. The Share Acquisition Loan had no outstanding principal balance at December 31, 2018 and 2017 . The Company made the Share Acquisition Loan to the ESOP in the original principal amount of $19.6 million in connection with the Company’s mutual to stock conversion in June of 2005. The proceeds of the Share Acquisition Loan were used by the ESOP to purchase 1,957,300 shares of the Company’s common stock issued in the subscription offering at a price of $10.00 per share. The Share Acquisition Loan was secured by a pledge of the acquired shares and the ESOP made annual loan payments with funds it received from the Bank’s discretionary contributions to the ESOP in subsequent years and dividends it received on unallocated shares. As loan payments were made, the Company recorded compensation expense based on the allocation of shares released. Contributions to the ESOP were zero and $1.1 million for the years ended December 31, 2018 and 2017 , including dividends and interest received on unallocated shares of $50,000 in 2017 . Expense related to the ESOP, net of dividends and interest received on unallocated ESOP shares, were zero and $1.1 million for the years ended December 31, 2018 and 2017 , respectively. Shares held by the ESOP were as follows: December 31, 2018 2017 Allocated to participants 885,896 1,203,810 Distributed to participants (885,896 ) (317,914 ) Total ESOP shares — 885,896 Profit Sharing Plan/401(k) Plan . The Company has a defined contribution plan (“profit sharing plan”) covering all of its eligible employees. Employees are eligible to participate in the profit sharing plan after attainment of age 21 and completion of one year of service. The Company provides a match of $ 0.50 on each $1.00 of contribution up to 6% of eligible compensation beginning April 1, 2007. The Company may also contribute an additional amount annually at the discretion of the Board of Directors. Contributions totaling $506,000 and $328,000 were made for the years ended December 31, 2018 and 2017 , respectively.

Equity Incentive Plans (Notes)

Equity Incentive Plans (Notes)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plans	EQUITY INCENTIVE PLANS On June 27, 2006, the Company’s stockholders approved the BankFinancial Corporation 2006 Equity Incentive Plan, which authorized the Human Resources Committee of the Board of Directors of the Company to grant a variety of cash- and equity-based incentive awards, including stock options, stock appreciation rights, restricted stock, performance shares and other incentive awards, to employees and directors aggregating up to 3,425,275 shares of the Company’s common stock. The Plan provided that no awards may be granted under the Plan after the ten -year anniversary of the Effective Date. Consequently, no further awards will be granted under this Plan. During the year ended December 31, 2017, all 1,752,156 stock options were exercised. All stock options were exercised on a net settlement basis, using a portion of the shares obtained upon exercise to pay the exercise price of the stock option. The net settlements resulted in the issuance of 280,554 shares of the Company's common stock. Certain employees also chose to use a portion of the net shares received upon the exercise to pay required tax withholdings. This reduced the net shares issued by 82,528 shares to 198,026 shares. There are no stock options available for grant at December 31, 2018 or 2017. For the years ended December 31, 2018 and 2017 the Company recognized no stock-based compensation expenses relating to the granting of stock options. A summary of the activity in the stock option plan for 2017 follows: Stock Options Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (1) Stock options outstanding at January 1, 2017 1,752,156 $ 12.30 0.48 $ 4,422 Stock options granted — — Stock options exercised (1,752,156 ) 12.30 Stock options outstanding at December 31, 2017 — $ — 0.00 $ — (1) Stock option aggregate intrinsic value represents the number of shares subject to options multiplied by the difference (if positive) in the closing market price of the common stock underlying the options on the date shown and the weighted average exercise price. The Human Resources Committee of the Board of Directors may grant shares of restricted stock to certain employees and directors of the Company. The awards generally vest annually over varying periods from three to five years and vesting is subject to acceleration in certain circumstances. The cost of such awards will be accrued ratably as compensation expense over such respective periods based on expected vesting dates. The Company recognized zero expense relating to the grant of shares of restricted stock during the years ended December 31, 2018 and 2017 . As of December 31, 2018 , there was no unrecognized compensation cost related to unvested shares of restricted stock. There are no shares of restricted stock available for grant at December 31, 2018 . Restricted Stock Number of Shares (1) Weighted Average Fair Value at Grant Date Weighted Average Term to Vest (in years) Aggregate Intrinsic Value (2) Shares outstanding at January 1, 2017 940 $ 8.14 0.74 $ 14 Shares granted — — Shares vested — — Shares forfeited — — Shares outstanding at December 31, 2017 940 $ 8.14 0.00 $ 14 Shares granted — — Shares vested (694 ) 8.14 Shares forfeited (246 ) 8.14 Shares outstanding at December 31, 2018 — $ — 0.00 $ — (1) The end of period balances consist only of unvested shares. (2) Restricted stock aggregate intrinsic value represents the number of shares of restricted stock multiplied by the market price of the common stock underlying the outstanding shares on the date shown.

Loan Commitments and Other Off-

Loan Commitments and Other Off-Balance Sheet Activities (Notes)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Loan Commitments and Other Off-Balance Sheet Activities	The Company is party to various financial instruments with off-balance-sheet risk. The Company uses these financial instruments in the normal course of business to meet the financing needs of customers and to effectively manage exposure to interest rate risk. These financial instruments include commitments to extend credit, standby letters of credit, unused lines of credit, and commitments to sell loans. When viewed in terms of the maximum exposure, those instruments may involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated statements of financial condition. Credit risk is the possibility that a counterparty to a financial instrument will be unable to perform its contractual obligations. Interest rate risk is the possibility that, due to changes in economic conditions, the Company’s net interest income will be adversely affected. The following is a summary of the contractual or notional amount of each significant class of off-balance-sheet financial instruments outstanding. The Company’s exposure to credit loss in the event of nonperformance by the counterparty for commitments to extend credit, standby letters of credit, and unused lines of credit is represented by the contractual notional amount of these instruments. The contractual or notional amounts are as follows: December 31, 2018 2017 Financial instruments wherein contractual amounts represent credit risk Commitments to extend credit $ 75,180 $ 46,615 Standby letters of credit 5,965 6,757 Unused lines of credit 152,554 129,207 Commitments to sell mortgages — — Commitments to extend credit are generally made for periods of 60 days or less. The fixed-rate loans commitment totaled $44.5 million with interest rates ranging from 4.12% to 7.00% and maturities ranging from 1 to 30 years. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do 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 it is deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation of the customers.

Fair Value (Notes)

Fair Value (Notes)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. There are three levels of inputs that may be used to measure fair values: • Level 1 – Quoted prices (unadjusted) for identical assets or liabilities in active markets that the entity has the ability to access as of the measurement date. • Level 2 – Significant other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. • Level 3 – Significant unobservable inputs that reflect a company’s own assumptions about the assumptions that market participants would use in pricing an asset or liability. The Company used the following methods and significant assumptions to estimate the fair value of each type of financial instrument: Securities available-for-sale : The fair values of marketable equity securities are generally determined by quoted prices, in active markets, for each specific security (Level 1). If Level 1 measurement inputs are not available for a marketable equity security, we determine its fair value based on the quoted price of a similar security traded in an active market (Level 2). The fair values of debt securities are generally determined by matrix pricing, which is a mathematical technique widely used in the industry to value debt securities without relying exclusively on quoted prices for the specific securities, but rather by relying on the securities’ relationship to other benchmark quoted securities (Level 2). Other investments : Other investments includes our investments in equity securities without readily determinable fair values. Equity investments without readily determinable fair values, includes our Visa Class B shares, are categorized as Level 3. Our Visa Class B ownership includes shares acquired at no cost from our prior participation in Visa’s network while Visa operated as a cooperative. Impaired Loans: The fair value of impaired loans with specific allocations of the allowance for loan losses is generally based on recent real estate appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available for similar loans and collateral underlying such loans. Non-real estate collateral may be valued using an appraisal, net book value per the borrower’s financial statements, or aging reports, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of the valuation, and management’s expertise and knowledge of the client and client’s business, resulting in a Level 3 fair value classification. Impaired loans are evaluated on a quarterly basis for additional impairment and adjusted in accordance with the allowance policy. Other Real Estate Owned: Assets acquired through or instead of loan foreclosure are initially recorded at fair value less costs to sell when acquired, establishing a new cost basis. These assets are subsequently accounted for at lower of cost or fair value less estimated costs to sell. Fair value is commonly based on recent real estate appraisals which are updated no less frequently than annually. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach with data from comparable properties. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available. Real estate owned properties are evaluated on a quarterly basis for additional impairment and adjusted accordingly. The following table sets forth the Company’s financial assets that were accounted for at fair value and are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Securities available-for-sale: Certificates of deposit $ — $ 73,507 $ — $ 73,507 Municipal securities — 509 — 509 Mortgage-backed securities – residential — 10,478 — 10,478 Collateralized mortgage obligations – residential — 3,685 — 3,685 $ — $ 88,179 $ — $ 88,179 December 31, 2017 Securities available-for-sale: Certificates of deposit $ — $ 75,916 $ — $ 75,916 Equity mutual fund 499 — — 499 Mortgage-backed securities - residential — 12,472 — 12,472 Collateralized mortgage obligations – residential — 4,486 — 4,486 SBA-guaranteed loan participation certificates — 10 — 10 $ 499 $ 92,884 $ — $ 93,383 The following table sets forth the Company’s assets that were measured at fair value on a non-recurring basis: Fair Value Measurement Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Impaired loans - Nonresidential real estate $ — $ — $ 270 $ 270 Other real estate owned - Land $ — $ — $ 1 $ 1 Other investments (1) $ — $ — $ 3,427 $ 3,427 December 31, 2017 Other real estate owned: One–to–four family residential real estate $ — $ — $ 102 $ 102 Nonresidential real estate — — 814 814 Other real estate owned $ — $ — $ 916 $ 916 (1) See Note 1 for additional disclosures resulting from the Company's adoption of ASU 2016-01. At December 31, 2018 there was one nonresidential impaired loan with a carrying value of $270,000 and a valuation allowance of $27,000 at that was measured for impairment using the fair value of the collateral for collateral–dependent loans and which had specific valuation allowance, compared to no impaired loans at December 31, 2017 , resulting in a increase in the provision for loan losses of $27,000 for the year ended December 31, 2018 , compared to a decrease in the provision for loan losses of $26,000 for the year ended December 31, 2017 . OREO is carried at the lower of cost or fair value less costs to sell, had a carrying value of $24,000 less a valuation allowance of $23,000 , or $1,000 , at December 31, 2018 , compared to $1.2 million less a valuation allowance of $261,000 , or $916,000 at December 31, 2017 . There were $27,000 and $333,000 of valuation allowance additions charged to expense of OREO recorded for the years ended December 31, 2018 and 2017 , respectively. The following table presents quantitative information, based on certain empirical data with respect to Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis at December 31, 2018 : Fair Value Valuation Technique Unobservable Input Range (Weighted Average) Other real estate owned - Land $ 1 Sales comparison Discount applied to valuation 12.3% The following table presents quantitative information, based on certain empirical data with respect to Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis at December 31, 2017 : Fair Value Valuation Technique Unobservable Input Range (Weighted Average) Other real estate owned One-to-four family residential real estate $ 102 Sales comparison Discount applied to valuation 5.6% Nonresidential real estate 814 Sales comparison Comparison between sales and income approaches -3.66% to 15.22% (11.0%) $ 916 The carrying amount and estimated fair value of financial instruments is as follows: Fair Value Measurements at December 31, 2018 Using: Carrying Amount Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 98,204 $ 13,805 $ 84,399 $ — $ 98,204 Securities available-for-sale 88,179 — 88,179 — 88,179 Loans receivable, net of allowance for loan losses 1,323,793 — — 1,315,855 1,315,855 FHLB and FRB stock 8,026 — — — N/A Accrued interest receivable 4,952 — 249 4,703 4,952 Financial liabilities Noninterest-bearing demand deposits $ 230,041 $ — $ 230,041 $ — $ 230,041 NOW and money market accounts 531,781 531,781 531,781 Savings deposits 152,334 — 152,334 — 152,334 Certificates of deposit 438,328 — 436,598 — 436,598 Borrowings 21,049 — 21,050 — 21,050 Accrued interest payable 291 — 291 — 291 Fair Value Measurements at December 31, 2017 Using: Carrying Amount Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 127,592 $ 13,572 $ 114,020 $ — $ 127,592 Securities available-for-sale 93,383 499 92,884 — 93,383 Loans receivable, net of allowance for loan losses 1,314,651 — 1,323,139 — 1,323,139 FHLB and FRB stock 8,290 — — — N/A Accrued interest receivable 4,619 — 4,619 — 4,619 Financial liabilities Noninterest-bearing demand deposits $ 234,354 $ — $ 234,354 $ — $ 234,354 NOW and money market accounts 589,238 589,238 589,238 Savings deposits 160,501 — 160,501 — 160,501 Certificates of deposit 355,958 — 353,969 — 353,969 Borrowings 60,768 — 60,627 — 60,627 Accrued interest payable 147 — 147 — 147 For purposes of the above, the following assumptions were used: Cash and Cash Equivalents : The estimated fair values for cash and cash equivalents are based on their carrying value due to the short-term nature of these assets. Loans : At December 31, 2018 , the exit price observations are obtained from an independent third-party using its proprietary valuation model and methodology and may not reflect actual or prospective market valuations. The valuation is based on the probability of default, loss given default, recovery delay, prepayment, and discount rate assumptions. The new methodology is a result of the adoption of ASU 2016-01. At December 31, 2017, the estimated fair value for loans has been determined by calculating the present value of future cash flows based on the current rate the Company would charge for similar loans with similar maturities, applied for an estimated time period until the loan is assumed to be repriced or repaid. The methods utilized to estimate fair value of loans do not necessarily represent an exit price. FHLB and FRB Stock : It is not practicable to determine the fair value of FHLB and FRB stock due to the restrictions placed on its transferability. Deposit Liabilities : The estimated fair value for certificates of deposit has been determined by calculating the present value of future cash flows based on estimates of rates the Company would pay on such deposits, applied for the time period until maturity. The estimated fair values of noninterest-bearing demand, NOW, money market, and savings deposits are assumed to approximate their carrying values as management establishes rates on these deposits at a level that approximates the local market area. Additionally, these deposits can be withdrawn on demand. Borrowings : The estimated fair values of advances from the FHLB and notes payable are based on current market rates for similar financing. The estimated fair value of securities sold under agreements to repurchase is assumed to equal its carrying value due to the short-term nature of the liability. Accrued Interest : The estimated fair values of accrued interest receivable and payable are assumed to equal their carrying value. Off - Balance-Sheet Instruments : Off-balance-sheet items consist principally of unfunded loan commitments, standby letters of credit, and unused lines of credit. The estimated fair values of unfunded loan commitments, standby letters of credit, and unused lines of credit are not material. While the above estimates are based on management’s judgment of the most appropriate factors, as of the balance sheet date, there is no assurance that the estimated fair values would have been realized if the assets were disposed of or the liabilities settled at that date, since market values may differ depending on the various circumstances. The estimated fair values would also not apply to subsequent dates. In addition, other assets and liabilities that are not financial instruments, such as premises and equipment, are not included in the above disclosures.

Revenue From Contracts With Cus

Revenue From Contracts With Customers	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue From Contracts With Customers	REVENUE FROM CONTRACTS WITH CUSTOMERS All of the Company's revenue from contracts with customers in the scope of ASC 606 is recognized within noninterest income. The following table presents the Company's sources of noninterest income. Items outside of the scope of the ASC 606 are noted as such. For the years ended 2018 2017 Deposit service charges and fees $ 3,968 $ 3,953 Loan servicing fees (1) 439 326 Commercial mortgage brokerage fees (1) 138 — Residential mortgage banking fees (1) 119 215 Gain on sale of equity securities (1) 3,558 — Unrealized gain on equity securities (1) 3,427 — Gain on sale of premises held-for-sale 93 — Trust and insurance commissions and annuities income 937 971 Earnings on bank owned life insurance (1) 174 265 Bank-owned life insurance death benefit (1) 1,389 — Other (1) 635 678 Total noninterest income $ 14,877 $ 6,408 (1) Not within the scope of ASC 606 A description of the Company's revenue streams accounted for under ASC 606 follows: Deposit service charges and fees: The Company earns fees from its deposit customers based on specific types of transactions, account maintenance and overdraft services. Transaction-based fees, which include services such as ATM use fees, stop payment charges, statement rendering, and ACH fees, are recognized at the time the transaction is executed as that is the point in time the Company fulfills the customer's request. Account maintenance fees, which relate primarily to monthly maintenance, are earned over the course of a month, representing the period over which the Company satisfies the performance obligation. Overdraft fees are recognized at the point in time that the overdraft occurs. Service charges on deposits are withdrawn from the customer's account balance. Interchange income: The Company earns interchange fees from debit cardholder transactions conducted 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. Interchange income for the years ended December 31, 2018 and 2017 was $1.5 million and $1.4 million , respectively. Interchange income is included in deposit service charges and fees. Gain on sale of premises held-for-sale: On April 23, 2018, the Bank sold its office building located at 15W060 North Frontage Road, Burr Ridge, Illinois. The sale was to an unrelated party and title was transferred at closing. As such, the transaction constituted a sale and a net gain was recorded in the second quarter of 2018. Trust and insurance commissions and annuities income: The Company earns trust, insurance commissions and annuities income from its contracts with trust customers to manage assets for investment, and/or to transact on their accounts. These fees are primarily earned over time as the Company provides the contracted monthly or quarterly services and are generally assessed based on a tiered scale of the market value of assets under management (AUM) at month-end. Fees that are transaction based, including trade execution services, are recognized at the point in time that the transaction is executed, i.e., the trade date. Other related services provided include fees the Company earns, which are based on a fixed fee schedule, are recognized when the services are rendered. Gains/losses on sales of OREO: The Company records a gain or loss from the sale of OREO when control of the property transfers to the buyer, which generally occurs at the time of an executed deed. When the Company finances the sale of OREO to the buyer, the Company assesses whether the buyer is committed to perform their obligations under the contract and whether collectability of the transaction price is probable. Once these criteria are met, the OREO asset is derecognized and the gain or loss on sale is recorded upon the transfer of control of the property to the buyer. In determining the gain or loss on the sale, the Company adjusts the transaction price and related gain (loss) on sale if a significant financing component is present. OREO sales for the years ended December 31, 2018 and 2017 were not financed by the Bank.

Company Only Condensed Financia

Company Only Condensed Financial Information (Notes)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Company Only Condensed Financial Information	Condensed financial information of BankFinancial Corporation as of December 31, 2018 and 2017 and for the two years ended December 31, 2018 follows: Condensed Statements of Financial Condition December 31, 2018 2017 Assets Cash in subsidiary $ 11,227 $ 6,393 Investment in subsidiary 173,253 188,873 Deferred tax asset 1,999 2,076 Other assets 3,317 3,307 $ 189,796 $ 200,649 Liabilities and Stockholders' Equity Accrued expenses and other liabilities $ 2,646 $ 3,015 Total stockholders’ equity 187,150 197,634 $ 189,796 $ 200,649 Condensed Statements of Operations For the years ended 2018 2017 Interest income $ — $ 110 Dividends from subsidiary 36,044 10,629 Other expense 1,573 1,693 Income before income tax and undistributed subsidiary income 34,471 9,046 Income tax expense (benefit) (398 ) 290 Income before equity in undistributed subsidiary income 34,869 8,756 Equity in undistributed subsidiary income (excess distributions) (15,527 ) 248 Net income $ 19,342 $ 9,004 Condensed Statements of Cash Flows For the years ended 2018 2017 Cash flows from operating activities Net income $ 19,342 $ 9,004 Adjustments: Equity in undistributed subsidiary excess distributions 15,527 (248 ) Change in other assets 67 (2,712 ) Change in accrued expenses and other liabilities (369 ) 3,015 Net cash from operating activities 34,567 9,059 Cash flows from financing activities Net exercise of stock options — (1,237 ) Repurchase and retirement of common stock (23,284 ) (10,819 ) Cash dividends paid on common stock (6,449 ) (5,153 ) Net cash used in financing activities (29,733 ) (17,209 ) Net change in cash in subsidiary 4,834 (8,150 ) Beginning cash in subsidiary 6,393 14,543 Ending cash in subsidiary $ 11,227 $ 6,393

Selected Quarterly Financial Da

Selected Quarterly Financial Data (unaudited) (Notes)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unaudited)	SELECTED QUARTERLY FINANCIAL DATA (unaudited) For the year ended December 31, 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 14,748 $ 15,020 $ 15,373 $ 16,146 Interest expense 1,727 2,039 2,408 3,043 Net interest income 13,021 12,981 12,965 13,103 Provision for (recovery of) loan losses (258 ) 23 (23 ) 403 Net interest income 13,279 12,958 12,988 12,700 Noninterest income 1,539 3,094 1,570 8,674 Noninterest expense 9,959 10,215 9,425 11,155 Income before income taxes 4,859 5,837 5,133 10,219 Income tax expense 1,300 1,207 1,396 2,803 Net income $ 3,559 $ 4,630 $ 3,737 $ 7,416 Basic earnings per common share $ 0.20 $ 0.26 $ 0.22 $ 0.44 Diluted earnings per common share 0.20 0.26 0.22 0.44 The Company recorded net income of $7.4 million , or $0.44 per common share, for the fourth quarter of 2018 . The Company’s net interest income before provision for loan losses was $13.1 million due to stronger loan originations and improved asset quality, which was offset by increased interest bearing liabilities at higher cost of funds. The Company’s fourth quarter 2018 operating results include $3.6 million of gain on sale of Visa B stock common shares as well as $3.4 million in unrealized gain on Visa B common shares. Compensation expense includes $1.0 million in accrued expense, related to certain contract termination and severance payments. For the year ended December 31, 2017 First Second Third Fourth Interest income $ 13,362 $ 13,649 $ 14,121 $ 15,047 Interest expense 1,276 1,456 1,615 1,742 Net interest income 12,086 12,193 12,506 13,305 Provision for (recovery of) loan losses 161 49 (225 ) (72 ) Net interest income 11,925 12,144 12,731 13,377 Noninterest income 1,544 1,607 1,623 1,634 Noninterest expense 11,266 9,607 10,200 9,318 Income before income taxes 2,203 4,144 4,154 5,693 Income tax expense 322 1,572 594 4,702 Net income $ 1,881 $ 2,572 $ 3,560 $ 991 Basic earnings per common share $ 0.10 $ 0.14 $ 0.20 $ 0.06 Diluted earnings per common share 0.10 0.14 0.20 0.06 The Company recorded net income of $1.0 million , or $0.06 per common share, for the fourth quarter of 2017. The Company’s net interest income before provision for loan losses was $13.3 million due to stronger loan originations and improved asset quality. which was offset by increased interest bearing liabilities at higher cost of funds. The Company’s fourth quarter 2017 operating results included a $2.5 million provision for taxes related to Tax Cuts and Jobs Act of 2017.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation : BankFinancial Corporation, a Maryland corporation headquartered in Burr Ridge, Illinois (the “Company”), is the owner of all of the issued and outstanding capital stock of BankFinancial, National Association (the “Bank”).
Principles of Consolidation	Principles of Consolidation : The consolidated financial statements include the accounts of and transactions of BankFinancial Corporation, the Bank, and the Bank’s wholly-owned subsidiaries, Financial Assurance Services, Inc. and BFIN Asset Recovery Company, LLC (formerly BF Asset Recovery Corporation) (collectively, “the Company”) and have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All significant intercompany accounts and transactions have been eliminated.
Use of Estimates	Use of Estimates : To prepare financial statements in conformity with GAAP, management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ.
Cash Flows	Interest-bearing Deposits in Other Financial Institutions : Interest-bearing deposits in other financial institutions maturing in less than 90 days are carried at cost. Cash Flows : Cash and cash equivalents include cash, deposits with other financial institutions maturing in less than 90 days, and daily federal funds sold. Net cash flows are reported for customer loan and deposit transactions, interest bearing deposits in other financial institutions, borrowings, and advance payments by borrowers for taxes and insurance.
Securities	Securities available-for -sale : Debt securities are classified as available-for-sale when they might be sold before maturity. Prior to January 1, 2018, equity securities with readily determinable fair values were classified as available-for-sale. Securities available-for-sale are carried at fair value, with unrealized holding gains and losses reported in other comprehensive income (loss), net of tax. Interest income includes amortization of purchase premium or discount. Premiums and discounts on securities are amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Gains and losses on sales are based on the amortized cost of the security sold. Declines in the fair value of securities below their cost that are other-than-temporary are reflected as realized losses. In determining if losses are other-than-temporary, management considers: (1) the length of time and extent that fair value has been less than cost or adjusted cost, as applicable, (2) the financial condition and near term prospects of the issuer, and (3) whether the Company has the intent to sell the debt security or it is more likely than not that the Company will be required to sell the debt security before the anticipated recovery.
Federal Home Loan Bank Stock	Federal Home Loan Bank (“FHLB”) Stock : The Bank is a member of the FHLB system. Members are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest in additional amounts. FHLB stock is carried at cost, classified as a restricted security, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income.
Loans And Loan Income	Loans and Loan Income : Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal balance outstanding, net of the allowance for loan losses, premiums and discounts on loans purchased, and net deferred loan costs. Interest income on loans is recognized in income over the term of the loan based on the amount of principal outstanding. Premiums and discounts associated with loans purchased are amortized over the contractual term of the loan using the level–yield method. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level‑yield method without anticipating prepayments. Interest income is reported on the interest method. Interest income is discontinued at the time a loan is 90 days past due or when we do not expect to receive full payment of interest or principal. Past due status is based on the contractual terms of the loan. All interest accrued but not received for loans that have been placed on nonaccrual status is reversed against interest income. Interest received on such loans is accounted for on the cash–basis or cost–recovery method until qualifying for return to accrual status. Once a loan is placed on nonaccrual status, the borrower must generally demonstrate at least six months of payment performance before the loan is eligible to return to accrual status. Generally, the Company utilizes the “90 days delinquent, still accruing” category of loan classification when: (1) the loan is repaid in full shortly after the period end date; (2) the loan is well secured and there are no asserted or pending legal barriers to its collection; or (3) the borrower has remitted all scheduled payments and is otherwise in substantial compliance with the terms of the loan, but the processing of payments actually received or the renewal of a loan has not occurred for administrative reasons.
Impaired Loans	Impaired Loans: Impaired loans principally consist of nonaccrual loans and troubled debt restructurings (“TDRs”). A loan is considered impaired when, based on current information and events, management believes that it is probable that we will be unable to collect all amounts due (both principal and interest) according to the original contractual terms of the loan agreement. Once a loan is determined to be impaired, the amount of impairment is measured based on the loan's observable fair value, the fair value of the underlying collateral less selling costs if the loan is collateral-dependent, or the present value of expected future cash flows discounted at the loan's effective interest rate. If the measurement of the impaired loan is less than the recorded investment in the loan, the bank's allowance for the impaired collateral dependent loan under ASC 310-10-35 is based on fair value (less costs to sell), but the charge-off (the confirmed “loss”) is based on the appraised value. The remaining recorded investment in the loan after the charge-off will have a loan loss allowance for the amount by which the estimated fair value of the collateral (less costs to sell) is less than its appraised value. Impaired loans with specific reserves are reviewed quarterly for any changes that would affect the specific reserve. Any impaired loan for which a determination has been made that the economic value is permanently reduced is charged-off against the allowance for loan losses to reflect its current economic value in the period in which the determination has been made. At the time a collateral-dependent loan is initially determined to be impaired, we review the existing collateral appraisal. If the most recent appraisal is greater than a year old, a new appraisal is obtained on the underlying collateral. Appraisals are updated with a new independent appraisal at least annually and are formally reviewed by our internal appraisal department upon receipt of a new appraisal. All impaired loans and their related reserves are reviewed and updated each quarter.
Troubled Debt Restructurings	Troubled Debt Restructurings : A loan is classified as a troubled debt restructuring when a borrower is experiencing financial difficulties that leads to a restructuring of the loan, and the Company grants concessions to the borrower in the restructuring that it would not otherwise consider. These concessions may include rate reductions, principal forgiveness, extension of maturity date and other actions intended to minimize potential losses. In determining whether a debtor is experiencing financial difficulties, the Company considers if the debtor is in payment default or would be in payment default in the foreseeable future without the modification, the debtor declared or is in the process of declaring bankruptcy, there is substantial doubt that the debtor will continue as a going concern, the debtor has securities that have been or are in the process of being delisted, the debtor's entity-specific projected cash flows will not be sufficient to service any of its debt, or the debtor cannot obtain funds from sources other than the existing creditors at a market rate for debt with similar risk characteristics. In determining whether the Company has granted a concession, the Company assesses, if it does not expect to collect all amounts due, whether the current value of the collateral will satisfy the amounts owed, whether additional collateral or guarantees from the debtor will serve as adequate compensation for other terms of the restructuring, and whether the debtor otherwise has access to funds at a market rate for debt with similar risk characteristics. Periodically, the Company will restructure a note into two separate notes (A/B structure), charging off the entire B portion of the note. The A note is structured with appropriate loan-to-value and cash flow coverage ratios that provide for a high likelihood of repayment. The A note is classified as a nonperforming note until the borrower has displayed a historical payment performance for a reasonable time prior to and subsequent to the restructuring. A period of sustained repayment for at least six months generally is required to return the note to accrual status provided that management has determined that the performance is reasonably expected to continue. The A note will be classified as a restructured note (either performing or nonperforming) through the calendar year of the restructuring that the historical payment performance has been established.
Allowance for Loan Losses	Allowance for Loan Losses: The Company establishes provisions for loan losses, which are charged to the Company’s results of operations to maintain the allowance for loan losses to absorb probable incurred credit losses in the loan portfolio. In determining the level of the allowance for loan losses, the Company considers past and current loss experience, trends in classified loans, evaluations of real estate collateral, current economic conditions, volume and type of lending, adverse situations that may affect a borrower’s ability to repay a loan and the levels of nonperforming and other classified loans. The amount of the allowance is based on estimates and the ultimate losses may vary from the estimates as more information becomes available or events change. The Company provides for loan losses based on the allowance method. Accordingly, all loan losses are charged to the related allowance and all recoveries are credited to it. Additions to the allowance for loan losses are provided by charges to income based on various factors that, in our judgment, deserve current recognition in estimating probable incurred credit losses. The Company reviews the loan portfolio on an ongoing basis and makes provisions for loan losses on a quarterly basis to maintain the allowance for loan losses in accordance with GAAP. The allowance for loan losses consists of two components: • specific allowances established for any impaired residential non-owner occupied mortgage, multi-family mortgage, nonresidential real estate, construction and land, commercial, and commercial lease loans for which the recorded investment in the loan exceeds the measured value of the loan; and • general allowances for loan losses for each loan class based on historical loan loss experience; and adjustments to historical loss experience (general allowances), maintained to cover uncertainties that affect our estimate of probable incurred credit losses for each loan class. The adjustments to historical loss experience are based on our evaluation of several factors, including levels of, and trends in, past due and classified loans; levels of, and trends in, charge–offs and recoveries; trends in volume and terms of loans, including any credit concentrations in the loan portfolio; experience and ability of lending management and other relevant staff; and national and local economic trends and conditions. The Company evaluates the allowance for loan losses based upon the combined total of the specific and general components. Generally, when the loan portfolio increases, absent other factors, the allowance for loan loss methodology results in a higher dollar amount of estimated probable incurred credit losses than would be the case without the increase. Conversely, when the loan portfolio decreases, absent other factors, the allowance for loan loss methodology generally results in a lower dollar amount of estimated probable losses than would be the case without the decrease. The loss ratio used in computing the required general loan loss reserve allowance for a given class of loan consists of (i) the actual loss ratio (measured on a weighted, rolling twelve-quarter basis), (ii) the change in credit quality within the specific loan class during the period, (iii) the actual inherent risk factor assigned to the specific loan class and (iv) the actual concentration of risk factor assigned to the specific loan class (collectively, the “Specific Loan Class Risk Factors”). The Specific Loan Class Risk Factors are weighted equally in the calculation. In addition, two additional quantitative factors, the National Economic risk factor and the Local Economic risk factor, are also components of the computation but are given different weightings in their computation due to their relative applicability to the specific loan class in the context of the effect of national and local economic conditions on their risk profile and performance.
Uncollected Interest	When a loan is on non-accrual status and the ultimate collectability of the total principal of an impaired loan is in doubt, all payments are applied to principal under the cost recovery method. Alternatively, when a loan is on non-accrual status but there is doubt concerning only the ultimate collectability of interest, contractual interest is credited to interest income only when received, under the cash basis method pursuant to the provisions of FASB ASC 310–10, as applicable. In all cases, the average balances are calculated based on the month–end balances of the financing receivables within the period reported pursuant to the provisions of FASB ASC 310–10, as applicable.
Mortgage Servicing Rights	Mortgage Servicing Rights : Mortgage servicing rights are recognized separately when they are acquired through sales of loans. When mortgage loans are sold, servicing rights are initially recorded at fair value and gains on sales of loans are recorded in the statement of operations. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the servicing cost per loan, the discount rate, the escrow float rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses. The Company compares the valuation model inputs and results to published industry data in order to validate the model results and assumptions. All classes of servicing assets are subsequently measured using the amortization method which requires servicing rights to be amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. Servicing assets are evaluated for impairment based upon the fair value of the rights as compared to carrying amount. Impairment is determined by stratifying rights into groupings based on predominant risk characteristics, such as interest rate, loan type and investor type. Impairment is recognized through a valuation allowance for an individual grouping, to the extent that fair value is less than the carrying amount. If the Company later determines that all or a portion of the impairment no longer exists for a particular grouping, a reduction of the allowance may be recorded as an increase to income. Changes in valuation allowances are reported with amortization and impairment of servicing assets on the statement of operations. The fair values of servicing rights are subject to significant fluctuations as a result of changes in estimated and actual prepayment speeds and default rates and losses. Servicing fee income that is reported on the statement of operations as loan servicing fees is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal; or a fixed amount per loan and are recorded as income when earned. Late fees and ancillary fees related to loan servicing are not material.
Other Real Estate Owned	Other Real Estate Owned ("OREO") : Foreclosed assets are initially recorded at fair value less cost to sell when acquired, establishing a new cost basis. Physical possession of residential real estate property collateralizing a consumer mortgage loan occurs when the legal title is obtained upon completion of foreclosure or when the borrower conveys all interest in the property to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. These assets are subsequently accounted for at a lower of cost or fair value less estimated cost to sell. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating expenses, gains and losses on disposition, and changes in the valuation allowance are reported in noninterest expense as operations of other real estate owned.
Premises and Equipment	Premises and Equipment : Land is carried at cost. Premises and equipment are stated at cost less accumulated depreciation. Depreciation is included in noninterest expense and is computed on the straight-line method over the estimated useful lives of the assets. Useful lives are estimated to be 25 to 40 years for buildings and improvements that extend the life of the original building, ten to 20 years for routine building improvements, five to 15 years for furniture and equipment, two to five years for computer hardware and software and no greater than four years on automobiles. The cost of maintenance and repairs is charged to expense as incurred and significant repairs are capitalized.
Goodwill and Other Intangible Assets	Other Intangible Assets : Intangible assets acquired in a purchase business combination with definite useful lives are amortized over their estimated useful lives to their estimated residual values. Core deposit intangible assets (“CDI”), are recognized at the time of acquisition based on valuations prepared by independent third parties or other estimates of fair value. In preparing such valuations, variables such as deposit servicing costs, attrition rates, and market discount rates are considered. CDI assets are amortized to expense over their useful lives.
Bank Owned Life Insurance	Bank Owned Life Insurance: The Company has purchased life insurance policies on certain key executives. The Company owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement.
Long-Term Assets	Long-Term Assets : Premises and equipment, core deposit and other intangible assets, and other long-term assets are reviewed for impairment when events indicate that their carrying amount may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value.
Loan Commitments and Related Financial Instruments	Loan Commitments and Related Financial Instruments : Financial instruments include off-balance-sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded.
Income Taxes	Income Taxes : Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Under GAAP, a deferred tax asset valuation allowance is required to be recognized if it is “more likely than not” that the deferred tax asset will not be realized. The determination of the realizability of the deferred tax assets is highly subjective and dependent upon judgment concerning management’s evaluation of both positive and negative evidence, the forecasts of future taxable income, applicable tax planning strategies, and assessments of current and future economic and business conditions. The Company considers both positive and negative evidence regarding the ultimate realizability of our deferred tax assets. Examples of positive evidence may include the existence, if any, of taxes paid in available carry-back years and the likelihood that taxable income will be generated in future periods. Examples of negative evidence may include a cumulative loss in the current year and prior two years and negative general business and economic trends. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period of the enactment date. This analysis is updated quarterly and adjusted as necessary. At December 31, 2018 , the Company had a net deferred tax asset of $6.2 million . A tax position is recognized as a benefit only if it is "more likely than not" that the tax position would be sustained in a tax examination, presuming that a tax examination will occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely to be realized on examination. For tax positions not meeting the "more likely than not" test, no tax benefit is recorded.
Retirement Plans	Retirement Plans : Employee 401(k) and profit sharing plan expense is the amount of matching contributions and any annual discretionary contribution made at the discretion of the Company’s Board of Directors. Deferred compensation expense allocates the benefits over years of service.
Employee Stock Ownership Plan (ESOP)
Earnings (Loss) Per Common Share	Earnings per Common Share : Basic earnings per common share is net income divided by the weighted average number of common shares outstanding during the period. ESOP shares are considered outstanding for this calculation unless unearned. Diluted earnings per common share is net income divided by the weighted average number of common shares outstanding during the period plus the dilutive effect of restricted stock shares and the additional potential shares issuable under stock options.
Loss Contingencies	Loss Contingencies : Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe that there are such matters that will have a material effect on the financial statements as of December 31, 2018 .
Restrictions on Cash	Restrictions on Cash : Cash on hand or on deposit with the Federal Reserve Bank that is required to meet regulatory reserve and clearing requirements.
Fair Value of Financial Instruments	Fair Values of Financial Instruments : Fair values of financial instruments are estimated using relevant market value information and other assumptions, as more fully disclosed in a separate note. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect the estimates.
Comprehensive Income (Loss)	Comprehensive Income : Comprehensive income consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available-for-sale, net of tax, which are also recognized as separate components of stockholders’ equity.
Stock-based Compensation
Transfers of Financial Assets	Transfers of Financial Assets: Transfers of financial assets are accounted for as sales when control over the assets has been relinquished. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company, the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Operating Segments	Operating Segments: While management monitors the revenue streams of the various products and services, operations are managed and financial performance is evaluated on a Company-wide basis. Operating results are not reviewed by senior management to make resource allocation or performance decisions. Accordingly, all of the financial service operations are considered by management to be aggregated in one reportable operating segment.
Reclassifications	Reclassifications : Certain reclassifications have been made in the prior year’s financial statements to conform to the current year’s presentation.
Recent Accounting Pronouncements	Accounting Standards In May 2014, the FASB issued an update (ASU No. 2014-09, Revenue from Contracts with Customers) creating FASB Topic 606, Revenue from Contracts with Customers. The guidance in this update affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (for example, insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides steps to follow to achieve the core principle. An entity should disclose sufficient information to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Qualitative and quantitative information is required about contracts with customers, significant judgments and changes in judgments, and assets recognized from the costs to obtain or fulfill a contract. The amendments in this update became effective for annual periods and interim periods within those annual periods beginning after December 15, 2017. Effective January 1, 2018, the Company adopted the new standard. The Company’s revenue streams that are in-scope from the update include: financed OREO sales; deposit fees, including ATM fees, overdraft fees, maintenance fees and dormancy fees; debit card fees, and trust fees. For the in-scope revenue streams, our current revenue recognition is not different than our prior revenue recognition under the update. The Company has infrequently financed an OREO sale. Our customer contracts generally do not have performance obligations and fees are assessed and collected as the transaction occurs. The Company’s fee income is not material for any individual income streams. The adoption of ASC 606 did not result in a change to the accounting for any of the in-scope revenue streams; as such, no cumulative effect adjustment was recorded. Refer to Note 16 - Revenue for Contracts with Customers for further discussion on the Company's accounting policies for revenue sources within the scope of ASC 606. In January 2016, the FASB issued an update (ASU No. 2016-01, Financial Instruments - Recognition and Measurement of Financial Assets and Liabilities). The new guidance is intended to improve the recognition and measurement of financial instruments by requiring: equity investments (other than equity method or consolidation) to be measured at fair value with changes in fair value recognized in net income; public business entities to use the exit price notion when measuring the fair value of financial instruments at amortized cost for disclosure purposes; separate presentation of financial assets and financial liabilities by measurement category and form of financial assets ( i.e., securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements; eliminating the requirement to disclose the fair value of financial instruments measured at amortized cost for organizations that are not public business entities; eliminating the requirement for non-public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is to be required to be disclosed for financial instruments measured at amortized cost on the balance sheet; and requiring a reporting organization to present separately in other comprehensive income the portion of the total change in fair value of a liability resulting from the change in the instrument-specific credit risk (also referred to as “own credit”) when the organization has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. The new guidance became effective for public business entities for fiscal years beginning after December 15, 2017. Upon adoption, the new pronouncement did not have a significant impact on our Statement of Operations, as we had one equity security that was valued at $499,000 on January 1, 2018 and was subsequently sold in 2018. At December 31, 2018 , the exit price observations for the loan portfolio were obtained from an independent third-party using its proprietary valuation model and methodology and may not reflect actual or prospective market valuations. The valuation is based on the probability of default, loss given default, recovery delay, prepayment, and discount rate assumptions. The new methodology is a result of the adoption of ASU 2016-01. In March of 2017, the FASB issued ASU No. 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities” (“ASU 2017-08”). This guidance shortens the amortization period for premiums on certain callable debt securities to the earliest call date (with an explicit, noncontingent call feature that is callable at a fixed price and on a preset dates), rather than contractual maturity date as currently required under GAAP. The ASU does not impact instruments without preset call dates such as mortgage-backed securities. For instruments with contingent call features, once the contingency is resolved and the security is callable at a fixed price and preset date, the security is within the scope of the ASU. ASU 2017-08 is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, and early adoption is permitted. Effective January 2017, we early adopted the pronouncement. Adoption of the new pronouncement was immaterial to the consolidated financial statements. Newly Issued Not Yet Effective Accounting Standards In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)” (“ASU 2016-02”). The standard requires a lessee to recognize assets and liabilities on the balance sheet for leases with lease terms greater than 12 months. ASU 2016-02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. In July 2018, the Financial Accounting Standards Board issued new authoritative guidance to provide an additional transition method that allows entities to not apply this new guidance in the comparative periods presented in the financial statements and instead recognize a cumulative effect adjustment to the beginning retained earnings at the date of application. The Company evaluated the new guidance and its impact on the Company's statements of operations and financial condition. The Company will record an increase in assets and liabilities of $6.7 million as a result of recording additional lease contracts where the Company is lessee and expects to adopt the new guidance prospectively as of January 1, 2019 and to not restate comparative periods. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”). These amendments require the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better inform their credit loss estimates. Many of the loss estimation techniques applied today will still be permitted, although the inputs to those techniques will change to reflect the full amount of expected credit losses. In addition, the ASU amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. ASU 2016-13 is effective for SEC filers for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019 ( i.e. , January 1, 2020, for calendar year entities). Early application will be permitted for all organizations for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We are currently evaluating the impact that the standard will have on our consolidated financial statements. Our initial review indicates that we have maintained sufficient historical loan data to support the requirements of this pronouncement. In addition, we have begun tracking the average life of the various segments of our loan portfolio. We are currently evaluating various loss methodologies to determine their correlation to our various loan categories' historical performance. In August 2018, we contracted with a third-party vendor to provide a model and assist with assessing processes, portfolio segmentation, and model development.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Earnings Per Share	For the years ended 2018 2017 Net income available to common stockholders $ 19,342 $ 9,004 Average common shares outstanding 17,434,780 18,429,018 Less: Unearned ESOP shares — (148,179 ) Unvested restricted stock shares (435 ) (940 ) Weighted average common shares outstanding 17,434,345 18,279,899 Add - Net effect of dilutive stock options and unvested restricted stock — 437 Weighted average dilutive common shares outstanding 17,434,345 18,280,336 Basic earnings per common share $ 1.11 $ 0.49 Diluted earnings per common share $ 1.11 $ 0.49

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Unrealized gains and losses recognized in accumulated other comprehensive income (loss)	The fair value of securities and the related gross unrealized gains and losses recognized in accumulated other comprehensive income is as follows: Available-for-Sale Securities Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value December 31, 2018 Certificates of deposit $ 73,507 $ — $ — $ 73,507 Municipal securities 509 — — 509 Mortgage-backed securities - residential 10,116 400 (38 ) 10,478 Collateralized mortgage obligations - residential 3,676 11 (2 ) 3,685 $ 87,808 $ 411 $ (40 ) $ 88,179 December 31, 2017 Certificates of deposit $ 75,916 $ — $ — $ 75,916 Equity mutual fund 500 — (1 ) 499 Mortgage-backed securities - residential 11,969 520 (17 ) 12,472 Collateralized mortgage obligations - residential 4,481 16 (11 ) 4,486 SBA-guaranteed loan participation certificates 10 — — 10 $ 92,876 $ 536 $ (29 ) $ 93,383 Equity Investments (1) December 31, 2018 Visa Class B shares $ — 3,427 — $ 3,427 (1) Equity investments are included in Other Assets in the Consolidated Statements of Financial Condition.
Investments Classified by Contractual Maturity Date	The amortized cost and fair values of securities available-for-sale at December 31, 2018 by contractual maturity are shown below. Securities not due at a single maturity date are shown separately. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. December 31, 2018 Amortized Cost Fair Value Due in one year or less $ 73,507 $ 73,507 Due after one year through five years 509 509 74,016 74,016 Mortgage-backed securities - residential 10,116 10,478 Collateralized mortgage obligations - residential 3,676 3,685 $ 87,808 $ 88,179
Amortized cost and fair values of securities	Sales of equity securities were as follows: For the years ended 2018 2017 Proceeds $ 4,059 $ — Gross gains 3,572 — Gross losses (14 ) —
Securities with unrealized losses	Securities available-for-sale with unrealized losses at December 31, 2018 and 2017 not recognized in income are as follows: Less than 12 Months 12 Months or More Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss December 31, 2018 Mortgage-backed securities - residential $ — $ — $ 904 $ (38 ) $ 904 $ (38 ) Collateralized mortgage obligations - residential — — 1,729 (2 ) 1,729 (2 ) $ — $ — $ 2,633 $ (40 ) $ 2,633 $ (40 ) December 31, 2017 Equity mutual fund $ 499 $ (1 ) $ — $ — $ 499 $ (1 ) Mortgage-backed securities - residential — — 1,149 (17 ) 1,149 (17 ) Collateralized mortgage obligations - residential — — 2,083 (11 ) 2,083 (11 ) $ 499 $ (1 ) $ 3,232 $ (28 ) $ 3,731 $ (29 )

Loans Receivable (Tables)

Loans Receivable (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Loans By Class Modified As Troubled Debt Restructurings With Payment Default
Loans Individually Evaluated For Impairment By Class Loans	The following tables present loans individually evaluated for impairment by class of loans: Loan Balance Recorded Investment Partial Charge-off Allowance for Loan Losses Allocated Average Investment in Impaired Loans Interest Income Recognized December 31, 2018 With no related allowance recorded One-to-four family residential real estate $ 2,751 $ 2,155 $ 575 $ — $ 3,274 $ 41 One-to-four family residential real estate - non-owner occupied 86 46 43 — 95 — Multi-family mortgage 654 653 — — 795 39 3,491 2,854 618 — 4,164 80 With an allowance recorded - Nonresidential real estate 356 270 93 27 21 — $ 3,847 $ 3,124 $ 711 $ 27 $ 4,185 $ 80 Loan Balance Recorded Investment Partial Charge-off Allowance for Loan Losses Allocated Average Investment in Impaired Loans Interest Income Recognized December 31, 2017 With no related allowance recorded One-to-four family residential real estate $ 5,049 $ 4,248 $ 806 $ — $ 4,212 $ 197 Multi-family mortgage 958 948 — — 847 41 $ 6,007 $ 5,196 $ 806 $ — $ 5,059 $ 238
Troubled Debt Restructurings on Financing Receivables	The following table presents loans classified as TDRs: December 31, 2018 2017 One-to-four family residential real estate - Nonaccrual $ 17 $ 17
Loans Receivable Based On Impairment Method	The following tables present the balance in the allowance for loan losses and the loans receivable by portfolio segment and based on impairment method: Allowance for loan losses Loan Balances Individually evaluated for impairment Collectively evaluated for impairment Total Individually evaluated for impairment Collectively evaluated for impairment Total December 31, 2018 One-to-four family residential real estate $ — $ 699 $ 699 $ 2,218 $ 68,153 $ 70,371 Multi-family mortgage — 3,991 3,991 653 619,217 619,870 Nonresidential real estate 27 1,449 1,476 270 152,172 152,442 Construction and land — 4 4 — 172 172 Commercial loans — 1,517 1,517 — 187,406 187,406 Commercial leases — 755 755 — 299,394 299,394 Consumer — 28 28 — 1,539 1,539 $ 27 $ 8,443 $ 8,470 $ 3,141 $ 1,328,053 1,331,194 Net deferred loan origination costs 1,069 Allowance for loan losses (8,470 ) Loans, net $ 1,323,793 Allowance for loan losses Loan Balances Individually evaluated for impairment Collectively evaluated for impairment Total Individually evaluated for impairment Collectively evaluated for impairment Total December 31, 2017 One-to-four family residential real estate $ — $ 850 $ 850 $ 4,265 $ 93,549 $ 97,814 Multi-family mortgage — 3,849 3,849 949 587,434 588,383 Nonresidential real estate — 1,605 1,605 — 169,971 169,971 Construction and land — 32 32 — 1,358 1,358 Commercial loans — 1,357 1,357 — 152,552 152,552 Commercial leases — 655 655 — 310,076 310,076 Consumer — 18 18 — 1,597 1,597 $ — $ 8,366 $ 8,366 $ 5,214 $ 1,316,537 1,321,751 Net deferred loan origination costs 1,266 Allowance for loan losses (8,366 ) Loans, net $ 1,314,651
Schedule of Accounts, Notes, Loans and Financing Receivable	Loans receivable are as follows: December 31, 2018 2017 One-to-four family residential real estate $ 70,371 $ 97,814 Multi-family mortgage 619,870 588,383 Nonresidential real estate 152,442 169,971 Construction and land 172 1,358 Commercial loans 187,406 152,552 Commercial leases 299,394 310,076 Consumer 1,539 1,597 1,331,194 1,321,751 Net deferred loan origination costs 1,069 1,266 Allowance for loan losses (8,470 ) (8,366 ) Loans, net $ 1,323,793 $ 1,314,651
Financing Receivable Credit Quality Indicators	As of December 31, 2018 , and based on the most recent analysis performed, the risk category of loans by class of loans is as follows: Pass Special Mention Substandard Nonaccrual Total One-to-four family residential real estate $ 55,353 $ 495 $ 328 $ 993 $ 57,169 One-to-four family residential real estate - non-owner occupied 12,911 — 37 254 13,202 Multi-family mortgage - Illinois 279,021 — 216 — 279,237 Multi-family mortgage - Other 340,633 — — — 340,633 Nonresidential real estate 151,793 281 98 270 152,442 Construction — — — — — Land 172 — — — 172 Commercial loans: Regional commercial banking 34,764 4,810 — — 39,574 Health care 85,001 — 342 — 85,343 Direct commercial lessor 62,489 — — — 62,489 Commercial leases: Investment-grade 165,508 701 — — 166,209 Other 133,185 — — — 133,185 Consumer 1,529 3 7 — 1,539 $ 1,322,359 $ 6,290 $ 1,028 $ 1,517 $ 1,331,194 As of December 31, 2017 , and based on the most recent analysis performed, the risk category of loans by class of loans is as follows: Pass Special Mention Substandard Nonaccrual Total One-to-four family residential real estate $ 74,437 $ — $ 255 $ 1,914 $ 76,606 One-to-four family residential real estate - non-owner occupied 21,059 — 40 109 21,208 Multi-family mortgage - Illinois 290,765 — 225 368 291,358 Multi-family mortgage - Other 297,025 — — — 297,025 Nonresidential real estate 169,817 — 154 — 169,971 Construction 1,099 — — — 1,099 Land 259 — — — 259 Commercial loans: Regional commercial banking 36,373 4,528 — — 40,901 Health care 69,480 — 2,248 — 71,728 Direct commercial lessor 39,923 — — — 39,923 Commercial leases: Investment-grade 207,460 — — — 207,460 Other 102,616 — — — 102,616 Consumer 1,597 — — — 1,597 $ 1,311,910 $ 4,528 $ 2,922 $ 2,391 $ 1,321,751
Past Due Financing Receivables	The following tables present the aging of the recorded investment in past due loans as December 31, 2017 by class of loans: 30-59 Days Past Due 60-89 Days Past Due Greater Than 89 Days Past Due Total Past Due Loans Not Past Due Total One-to-four family residential real estate $ 86 $ 99 $ 1,801 $ 1,986 $ 74,216 $ 76,202 One-to-four family residential real estate - non-owner occupied 10 3 86 99 20,944 21,043 Multi-family mortgage - Illinois 172 — 364 536 287,171 287,707 Multi-family mortgage - Other — — — — 296,440 296,440 Nonresidential real estate 608 — — 608 166,071 166,679 Construction — — — — 1,103 1,103 Land — — — — 259 259 Commercial loans: Regional Commercial Banking — — — — 40,935 40,935 Health Care — — — — 71,738 71,738 Direct Commercial Lessor — — — — 40,237 40,237 Commercial leases: — Investment-grade 934 — — 934 207,747 208,681 Other 288 — — 288 102,873 103,161 Consumer — — — — 1,605 1,605 $ 2,098 $ 102 $ 2,251 $ 4,451 $ 1,311,339 $ 1,315,790 The following tables present the aging of the recorded investment in past due loans at December 31, 2018 by class of loans: 30-59 Days Past Due 60-89 Days Past Due Greater Than 89 Days Past Due Total Past Due Loans Not Past Due Total One-to-four family residential real estate $ 1,380 $ 637 $ 1,162 $ 3,179 $ 53,820 $ 56,999 One-to-four family residential real estate - non-owner occupied 387 10 78 475 12,460 12,935 Multi-family mortgage - Illinois 458 — — 458 275,283 275,741 Multi-family mortgage - Other — — — — 340,470 340,470 Nonresidential real estate — 270 — 270 149,271 149,541 Construction — — — — — — Land — — — — 169 169 Commercial loans: Regional Commercial Banking — — — — 39,712 39,712 Health Care — — — — 85,418 85,418 Direct Commercial Lessor — — — — 62,719 62,719 Commercial leases: — Investment-grade 505 — — 505 166,713 167,218 Other — — — — 133,958 133,958 Consumer 40 4 — 44 1,508 1,552 Total $ 2,770 $ 921 $ 1,240 $ 4,931 $ 1,321,501 $ 1,326,432
Schedule of Financing Receivables, Non Accrual Status	The following tables present the recorded investment in nonaccrual and loans 90 days or more past due still on accrual by class of loans: Loan Balance Recorded Investment Loans Past Due Over 90 Days, still accruing December 31, 2018 One-to-four family residential real estate $ 2,167 $ 1,162 $ — One-to-four family residential real estate – non owner occupied 270 78 — Nonresidential real estate 356 270 — $ 2,793 $ 1,510 $ — December 31, 2017 One-to-four family residential real estate $ 3,413 $ 1,918 $ — One-to-four family residential real estate – non owner occupied 308 109 — Multi-family mortgage 376 363 — $ 4,097 $ 2,390 $ —
Allowance for Credit Losses on Financing Receivables	Activity in the allowance for loan losses is as follows: For the years ended 2018 2017 Beginning balance $ 8,366 $ 8,127 Loans charged off: One-to-four family residential real estate (231 ) (318 ) Multi-family mortgage (35 ) (10 ) Nonresidential real estate (93 ) (165 ) Commercial loans (140 ) — Consumer (19 ) (10 ) (518 ) (503 ) Recoveries: One-to-four family residential real estate 206 145 Multi-family mortgage 34 70 Nonresidential real estate — 17 Construction and land 2 — Commercial loans 229 594 Commercial leases 5 2 Consumer 1 1 477 829 Net recoveries (charge-off) (41 ) 326 Provision for (recovery of) loan losses 145 (87 ) Ending balance $ 8,470 $ 8,366
Loans By Class Modified As Troubled Debt Restructuring On Financing Receivables

Other Real Estate (Tables)

Other Real Estate (Tables)	12 Months Ended
	Dec. 31, 2018
Other Real Estate Owned [Abstract]
real estate owned, rollforward [Table Text Block]	The following represents the roll forward of OREO and the composition of OREO properties. At and For the Years Ended December 31, 2018 2017 Beginning balance $ 2,351 $ 3,895 New foreclosed properties 1,482 2,766 Valuation adjustments (27 ) (333 ) Sales (2,580 ) (3,977 ) Ending balance $ 1,226 $ 2,351
Schedule of Real Estate Properties [Table Text Block]	December 31, 2018 December 31, 2017 Balance Valuation Allowance Net OREO Balance Balance Valuation Allowance Net OREO Balance One–to–four family residential $ 875 $ — $ 875 $ 836 $ (9 ) $ 827 Multi-family mortgage 276 — 276 — — — Nonresidential real estate 74 — 74 1,772 (252 ) 1,520 Land 24 (23 ) 1 48 (44 ) 4 $ 1,249 $ (23 ) $ 1,226 $ 2,656 $ (305 ) $ 2,351
other real estate owned valuation allowance rollforward [Table Text Block]	Activity in the valuation allowance is as follows: At and For the Years Ended December 31, 2018 2017 Beginning of year $ 305 $ 449 Additions charged to expense 27 333 Reductions from sales of other real estate owned (309 ) (477 ) End of year $ 23 $ 305

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant, Equipment And Leases [Abstract]
Property, Plant and Equipment	Year-end premises and equipment are as follows: December 31, 2018 2017 Land and land improvements $ 12,359 $ 12,265 Buildings and improvements 30,602 29,556 Furniture and equipment 10,039 9,678 Computer equipment 4,232 3,983 57,232 55,482 Accumulated depreciation (32,027 ) (30,626 ) $ 25,205 $ 24,856
Schedule of Future Minimum Rental Payments and Receipts for Operating Leases	2019 $ 927 2020 894 2021 913 2022 952 2023 939 Thereafter 3,250 $ 7,875 The projected minimum rental expense under existing leases, not including taxes, insurance, and maintenance, as of December 31, 2018 is as follows: 2019 $ 927 2020 894 2021 913 2022 952 2023 939 Thereafter 3,250 $ 7,875

Core Deposit Intangible (Tables

Core Deposit Intangible (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The following table presents the changes in the carrying amount of core deposit intangible, gross carrying amount, accumulated amortization, and net book value: December 31, 2018 2017 Balance at the beginning of the year $ 782 $ 1,305 Amortization (496 ) (523 ) Additions — — Net Carrying Value $ 286 $ 782 Gross carrying amount $ 5,932 $ 5,932 Accumulated amortization (5,646 ) (5,150 ) Net Carrying Value $ 286 $ 782
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Estimated amortization expense for each of the next five years is as follows: 2019 $ 184 2020 61 2021 34 2022 7 2023 —

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Schedule Of Deposits By Type	Composition of deposits is as follows: December 31, 2018 2017 Noninterest-bearing demand deposits $ 230,041 $ 234,354 Interest-bearing NOW accounts 275,830 289,657 Money market accounts 255,951 299,581 Savings deposits 152,334 160,501 Certificates of deposit 438,328 355,958 $ 1,352,484 $ 1,340,051
Schedule Of Maturities For Total Time Deposits	Scheduled maturities of certificates of deposit for the next five years are as follows: 2019 $ 290,219 2020 125,991 2021 17,359 2022 3,231 2023 1,528

Securities Sold Under Agreeme_2

Securities Sold Under Agreement to Repurchase Securities Sold Under Agreement to Repurchase (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Schedule of Repurchase Agreements	Securities sold under agreements to repurchase are shown below. Overnight and Continuous Up to 30 days 30 - 90 days Greater Than 90 days Total December 31, 2018 Repurchase agreements and repurchase-to-maturity transactions $ 1,049 $ — $ — $ — $ 1,049 Gross amount of recognized liabilities for repurchase agreements in Statement of Financial Condition $ 1,049 December 31, 2017 Repurchase agreements and repurchase-to-maturity transactions $ 768 $ — $ — $ — $ 768 Gross amount of recognized liabilities for repurchase agreements in Statement of Financial Condition $ 768

Federal Home Loan Bank Advanc_2

Federal Home Loan Bank Advances (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	At year-end, advances from the FHLB were as follows: December 31, 2018 2017 Contractual Rate Amount Contractual Rate Amount Fixed-rate advance from FHLB, due within 1 year 2.51 % $ 20,000 1.34 % $ 60,000

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense (Benefit)	The income tax expense is as follows: For the years ended 2018 2017 Current expense (benefit) $ 378 $ (2,658 ) Deferred expense 6,328 7,361 Expense due to enactment of federal tax reform — 2,487 Total income tax expense $ 6,706 $ 7,190
Schedule of Effective Income Tax Rate	A reconciliation of the provision for income taxes computed at the statutory federal corporate tax rate of 21% and 34% for 2018 and 2017 , respectively, to the income tax expense in the consolidated statements of operations follows: For the years ended 2018 2017 Expense computed at the statutory federal tax rate $ 5,470 $ 5,506 State taxes and other, net 1,564 (204 ) Bank owned life insurance (328 ) (90 ) ESOP/Share based compensation — (509 ) Expense due to enactment of federal tax reform — 2,487 $ 6,706 $ 7,190 Effective income tax rate 25.74 % 44.77 %
Schedule of Deferred Assets And Liabilities	The net deferred tax asset is as follows: December 31, 2018 2017 Gross Deferred tax assets Allowance for loan losses $ 2,279 $ 2,258 Alternative minimum tax, general business credit and net operating loss carryforwards 6,669 11,864 Tax deductible goodwill and core deposit intangible 561 801 Other 1,256 1,395 10,765 16,318 Gross Deferred tax liabilities Net deferred loan origination costs (1,186 ) (1,255 ) Purchase accounting adjustments (1,673 ) (1,744 ) Other (649 ) (619 ) Unrealized gain on securities (1,022 ) (137 ) (4,530 ) (3,755 ) $ 6,235 $ 12,563
Schedule of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: December 31, 2018 2017 Beginning of year $ 129 $ 57 Additions based on tax positions related to the current year 85 60 Additions for tax positions of prior years 4 12 Reductions due to the statute of limitations and reductions for tax positions of prior years (20 ) — End of year $ 198 $ 129

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	Actual and required capital amounts and ratios were: Actual Required for Capital Adequacy Purposes To be Well-Capitalized under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio December 31, 2018 Total capital (to risk-weighted assets): BankFinancial, NA 178,664 15.30 93,430 8.00 $ 116,787 10.00 % Tier 1 (core) capital (to risk-weighted assets): BankFinancial, NA 170,194 14.57 70,072 6.00 93,430 8.00 Common Tier 1 (CET1) BankFinancial, NA 170,194 14.57 52,554 4.50 75,912 6.50 Tier 1 (core) capital (to adjusted average total assets): BankFinancial, NA 170,194 11.03 61,721 4.00 77,151 5.00 December 31, 2017 Total capital (to risk-weighted assets): Consolidated $ 195,371 17.06 % $ 91,590 8.00 % N/A N/A BankFinancial, NA 188,582 16.48 91,572 8.00 $ 114,466 10.00 % Tier 1 (core) capital (to risk-weighted assets): Consolidated 187,005 16.33 68,692 6.00 N/A N/A BankFinancial, NA 180,216 15.74 68,679 6.00 91,572 8.00 Common Tier 1 (CET1) Consolidated 187,005 16.33 51,519 4.50 N/A N/A BankFinancial, NA 180,216 15.74 51,509 4.50 74,403 6.50 Tier 1 (core) capital (to adjusted average total assets): Consolidated 187,005 11.49 65,085 4.00 N/A N/A BankFinancial, NA 180,216 11.08 65,045 4.00 81,307 5.00

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Schedule of Employee Stock Ownership Plan (ESOP) Disclosures	Shares held by the ESOP were as follows: December 31, 2018 2017 Allocated to participants 885,896 1,203,810 Distributed to participants (885,896 ) (317,914 ) Total ESOP shares — 885,896

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock Option Activity	A summary of the activity in the stock option plan for 2017 follows: Stock Options Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (1) Stock options outstanding at January 1, 2017 1,752,156 $ 12.30 0.48 $ 4,422 Stock options granted — — Stock options exercised (1,752,156 ) 12.30 Stock options outstanding at December 31, 2017 — $ — 0.00 $ — (1) Stock option aggregate intrinsic value represents the number of shares subject to options multiplied by the difference (if positive) in the closing market price of the common stock underlying the options on the date shown and the weighted average exercise price.
Schedule of Unvested Shares of Restricted Stock	Restricted Stock Number of Shares (1) Weighted Average Fair Value at Grant Date Weighted Average Term to Vest (in years) Aggregate Intrinsic Value (2) Shares outstanding at January 1, 2017 940 $ 8.14 0.74 $ 14 Shares granted — — Shares vested — — Shares forfeited — — Shares outstanding at December 31, 2017 940 $ 8.14 0.00 $ 14 Shares granted — — Shares vested (694 ) 8.14 Shares forfeited (246 ) 8.14 Shares outstanding at December 31, 2018 — $ — 0.00 $ — (1) The end of period balances consist only of unvested shares. (2) Restricted stock aggregate intrinsic value represents the number of shares of restricted stock multiplied by the market price of the common stock underlying the outstanding shares on the date shown.

Loan Commitments and Other Of_2

Loan Commitments and Other Off-Balance Sheet Activities (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Off-balance Sheet Instruments Outstanding	The contractual or notional amounts are as follows: December 31, 2018 2017 Financial instruments wherein contractual amounts represent credit risk Commitments to extend credit $ 75,180 $ 46,615 Standby letters of credit 5,965 6,757 Unused lines of credit 152,554 129,207 Commitments to sell mortgages — —

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Company's financial instruments measured at fair values	The following table sets forth the Company’s financial assets that were accounted for at fair value and are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Securities available-for-sale: Certificates of deposit $ — $ 73,507 $ — $ 73,507 Municipal securities — 509 — 509 Mortgage-backed securities – residential — 10,478 — 10,478 Collateralized mortgage obligations – residential — 3,685 — 3,685 $ — $ 88,179 $ — $ 88,179 December 31, 2017 Securities available-for-sale: Certificates of deposit $ — $ 75,916 $ — $ 75,916 Equity mutual fund 499 — — 499 Mortgage-backed securities - residential — 12,472 — 12,472 Collateralized mortgage obligations – residential — 4,486 — 4,486 SBA-guaranteed loan participation certificates — 10 — 10 $ 499 $ 92,884 $ — $ 93,383
Schedule of Company's financial instruments measured on non recurring at fair values	The following table sets forth the Company’s assets that were measured at fair value on a non-recurring basis: Fair Value Measurement Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fair Value December 31, 2018 Impaired loans - Nonresidential real estate $ — $ — $ 270 $ 270 Other real estate owned - Land $ — $ — $ 1 $ 1 Other investments (1) $ — $ — $ 3,427 $ 3,427 December 31, 2017 Other real estate owned: One–to–four family residential real estate $ — $ — $ 102 $ 102 Nonresidential real estate — — 814 814 Other real estate owned $ — $ — $ 916 $ 916
Schedule of fair value quantitative information	The following table presents quantitative information, based on certain empirical data with respect to Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis at December 31, 2018 : Fair Value Valuation Technique Unobservable Input Range (Weighted Average) Other real estate owned - Land $ 1 Sales comparison Discount applied to valuation 12.3%
Carrying amount and estimated fair value of financial instruments	The carrying amount and estimated fair value of financial instruments is as follows: Fair Value Measurements at December 31, 2018 Using: Carrying Amount Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 98,204 $ 13,805 $ 84,399 $ — $ 98,204 Securities available-for-sale 88,179 — 88,179 — 88,179 Loans receivable, net of allowance for loan losses 1,323,793 — — 1,315,855 1,315,855 FHLB and FRB stock 8,026 — — — N/A Accrued interest receivable 4,952 — 249 4,703 4,952 Financial liabilities Noninterest-bearing demand deposits $ 230,041 $ — $ 230,041 $ — $ 230,041 NOW and money market accounts 531,781 531,781 531,781 Savings deposits 152,334 — 152,334 — 152,334 Certificates of deposit 438,328 — 436,598 — 436,598 Borrowings 21,049 — 21,050 — 21,050 Accrued interest payable 291 — 291 — 291 Fair Value Measurements at December 31, 2017 Using: Carrying Amount Level 1 Level 2 Level 3 Total Financial assets Cash and cash equivalents $ 127,592 $ 13,572 $ 114,020 $ — $ 127,592 Securities available-for-sale 93,383 499 92,884 — 93,383 Loans receivable, net of allowance for loan losses 1,314,651 — 1,323,139 — 1,323,139 FHLB and FRB stock 8,290 — — — N/A Accrued interest receivable 4,619 — 4,619 — 4,619 Financial liabilities Noninterest-bearing demand deposits $ 234,354 $ — $ 234,354 $ — $ 234,354 NOW and money market accounts 589,238 589,238 589,238 Savings deposits 160,501 — 160,501 — 160,501 Certificates of deposit 355,958 — 353,969 — 353,969 Borrowings 60,768 — 60,627 — 60,627 Accrued interest payable 147 — 147 — 147

Revenue From Contracts With C_2

Revenue From Contracts With Customers (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Noninterest Income Outside the Scope of ASC 606	tems outside of the scope of the ASC 606 are noted as such. For the years ended 2018 2017 Deposit service charges and fees $ 3,968 $ 3,953 Loan servicing fees (1) 439 326 Commercial mortgage brokerage fees (1) 138 — Residential mortgage banking fees (1) 119 215 Gain on sale of equity securities (1) 3,558 — Unrealized gain on equity securities (1) 3,427 — Gain on sale of premises held-for-sale 93 — Trust and insurance commissions and annuities income 937 971 Earnings on bank owned life insurance (1) 174 265 Bank-owned life insurance death benefit (1) 1,389 — Other (1) 635 678 Total noninterest income $ 14,877 $ 6,408

Company Only Condensed Financ_2

Company Only Condensed Financial Information (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Statements of Financial Condition	Condensed Statements of Financial Condition December 31, 2018 2017 Assets Cash in subsidiary $ 11,227 $ 6,393 Investment in subsidiary 173,253 188,873 Deferred tax asset 1,999 2,076 Other assets 3,317 3,307 $ 189,796 $ 200,649 Liabilities and Stockholders' Equity Accrued expenses and other liabilities $ 2,646 $ 3,015 Total stockholders’ equity 187,150 197,634 $ 189,796 $ 200,649
Condensed Statements of Operations	Condensed Statements of Operations For the years ended 2018 2017 Interest income $ — $ 110 Dividends from subsidiary 36,044 10,629 Other expense 1,573 1,693 Income before income tax and undistributed subsidiary income 34,471 9,046 Income tax expense (benefit) (398 ) 290 Income before equity in undistributed subsidiary income 34,869 8,756 Equity in undistributed subsidiary income (excess distributions) (15,527 ) 248 Net income $ 19,342 $ 9,004
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows For the years ended 2018 2017 Cash flows from operating activities Net income $ 19,342 $ 9,004 Adjustments: Equity in undistributed subsidiary excess distributions 15,527 (248 ) Change in other assets 67 (2,712 ) Change in accrued expenses and other liabilities (369 ) 3,015 Net cash from operating activities 34,567 9,059 Cash flows from financing activities Net exercise of stock options — (1,237 ) Repurchase and retirement of common stock (23,284 ) (10,819 ) Cash dividends paid on common stock (6,449 ) (5,153 ) Net cash used in financing activities (29,733 ) (17,209 ) Net change in cash in subsidiary 4,834 (8,150 ) Beginning cash in subsidiary 6,393 14,543 Ending cash in subsidiary $ 11,227 $ 6,393

Selected Quarterly Financial _2

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	For the year ended December 31, 2018 First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 14,748 $ 15,020 $ 15,373 $ 16,146 Interest expense 1,727 2,039 2,408 3,043 Net interest income 13,021 12,981 12,965 13,103 Provision for (recovery of) loan losses (258 ) 23 (23 ) 403 Net interest income 13,279 12,958 12,988 12,700 Noninterest income 1,539 3,094 1,570 8,674 Noninterest expense 9,959 10,215 9,425 11,155 Income before income taxes 4,859 5,837 5,133 10,219 Income tax expense 1,300 1,207 1,396 2,803 Net income $ 3,559 $ 4,630 $ 3,737 $ 7,416 Basic earnings per common share $ 0.20 $ 0.26 $ 0.22 $ 0.44 Diluted earnings per common share 0.20 0.26 0.22 0.44 For the year ended December 31, 2017 First Second Third Fourth Interest income $ 13,362 $ 13,649 $ 14,121 $ 15,047 Interest expense 1,276 1,456 1,615 1,742 Net interest income 12,086 12,193 12,506 13,305 Provision for (recovery of) loan losses 161 49 (225 ) (72 ) Net interest income 11,925 12,144 12,731 13,377 Noninterest income 1,544 1,607 1,623 1,634 Noninterest expense 11,266 9,607 10,200 9,318 Income before income taxes 2,203 4,144 4,154 5,693 Income tax expense 322 1,572 594 4,702 Net income $ 1,881 $ 2,572 $ 3,560 $ 991 Basic earnings per common share $ 0.10 $ 0.14 $ 0.20 $ 0.06 Diluted earnings per common share 0.10 0.14 0.20 0.06

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Mortgage Servicing Rights (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principal Amount Outstanding of Loans Held-in-portfolio	$ 76,200,000	$ 90,700,000
Escrow deposit	1,800,000	2,600,000
Fair value of mortgage servicing rights	420,000	$ 513,000
Valuation Allowance for Impairment of Recognized Servicing Assets, Balance	$ 0

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Premises and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Debt Securities, Available-for-sale	$ 88,179,000	$ 93,383,000
Transfer of Property to Held-for-sale	0	5,677,000
Premises held-for-sale	0	5,667,000
Gain on sale of premises held-for-sale	$ 93,000	$ 0
Building and building improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	25 years
Building and building improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	40 years
Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	10 years
Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	20 years
Furniture and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	5 years
Furniture and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	15 years
Computer Equipment And Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	2 years
Computer Equipment And Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	5 years
Automobiles [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Premises and Equipment, Useful life	4 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred Tax Assets, Net	$ 6,235				$ 12,563				$ 6,235	$ 12,563
Total income tax expense (benefit)	2,803	$ 1,396	$ 1,207	$ 1,300	4,702	$ 594	$ 1,572	$ 322	6,706	7,190
Unrecognized tax benefits	$ 198				$ 129				$ 198	$ 129	$ 57

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Accounting Standards (Details) $ in Thousands	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)equity_security
Debt Securities, Available-for-sale [Line Items]
Number of equity securities | equity_security			1
Debt Securities, Available-for-sale		$ 88,179	$ 93,383
Equity Funds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale		$ 0	$ 499
Accounting Standards Update 2016-02 [Member] | Pro Forma [Member]
Debt Securities, Available-for-sale [Line Items]
Operating Lease, Right-of-Use Asset	$ 6,700

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Earnings (Loss) Per Share, Basic and Diluted [Abstract]
Net income (loss) available to common stockholders	$ 7,416	$ 3,737	$ 4,630	$ 3,559	$ 991	$ 3,560	$ 2,572	$ 1,881	$ 19,342	$ 9,004
Average common shares outstanding (shares)									17,434,780	18,429,018
Less:
Unearned ESOP shares (shares)									0	(148,179)
Unvested restricted stock shares (shares)									(435)	(940)
Weighted average common shares outstanding (shares)									17,434,345	18,279,899
Add - Net effect of dilutive stock options and unvested restricted stock									0	437
Weighted average diluted common shares outstanding (shares)									17,434,345	18,280,336
Basic earnings (loss) per common share (usd per share)	$ 0.44	$ 0.22	$ 0.26	$ 0.20		$ 0.20	$ 0.14	$ 0.10	$ 1.11	$ 0.49
Diluted earnings (loss) per common share (usd per share)		$ 0.22	$ 0.26	$ 0.20	$ 0.06	$ 0.20	$ 0.14	$ 0.10	$ 1.11	$ 0.49

Securities - Fair Value of Secu

Securities - Fair Value of Securites (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 87,808	$ 92,876
Gross Unrealized Gains	411	536
Gross Unrealized Losses	(40)	(29)
Fair Value	88,179	93,383
Certificates of deposit [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	73,507	75,916
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	73,507	75,916
Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	509
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	509
Equity mutual fund [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		500
Gross Unrealized Gains		0
Gross Unrealized Losses		(1)
Fair Value	0	499
Mortgage - backed securities - residential [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,116	11,969
Gross Unrealized Gains	400	520
Gross Unrealized Losses	(38)	(17)
Fair Value	10,478	12,472
Collateralized mortgage obligations - residential [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,676	4,481
Gross Unrealized Gains	11	16
Gross Unrealized Losses	(2)	(11)
Fair Value	3,685	4,486
SBA-guaranteed loan participation certificates [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		10
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		$ 10
Common Class B [Member] | Equity mutual fund [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	0
Gross Unrealized Gains	3,427
Gross Unrealized Losses	0
Fair Value	$ 3,427

Securities - Proceeds and Gross

Securities - Proceeds and Gross Gains (Losses) From Sale of Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Proceeds	$ 4,059	$ 0
Gross gains	3,572	0
Gross losses	$ (14)	$ 0

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amortized cost and fair values of securities
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost	$ 73,507
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost	509
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost	74,016
Amortized Cost	87,808	$ 92,876
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value	73,507
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value		509
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value	74,016
Debt Securities, Available-for-sale	88,179	93,383
Mortgage - backed securities - residential [Member]
Amortized cost and fair values of securities
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost	10,116
Amortized Cost	10,116	11,969
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	10,478
Debt Securities, Available-for-sale	10,478	12,472
Collateralized mortgage obligations - residential [Member]
Amortized cost and fair values of securities
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost	3,676
Amortized Cost	3,676	4,481
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	3,685
Debt Securities, Available-for-sale	3,685	4,486
Collateral Pledged [Member]
Amortized cost and fair values of securities
Debt Securities, Available-for-sale, Restricted	$ 2,700	$ 3,700

Securities - Unrealized Losses

Securities - Unrealized Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	$ 0	$ 499
12 Months or More, Fair Value	2,633	3,232
Total, Fair Value	2,633	3,731
Less than 12 Months, Unrealized Loss	0	(1)
12 Months or More, Unrealized Loss	(40)	(28)
Unrealized Loss, Total	(40)	(29)
Equity Funds [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value		499
12 Months or More, Fair Value		0
Total, Fair Value		499
Less than 12 Months, Unrealized Loss		(1)
12 Months or More, Unrealized Loss		0
Unrealized Loss, Total		(1)
Mortgage Backed Securities Residential [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	0	0
12 Months or More, Fair Value	904	1,149
Total, Fair Value	904	1,149
Less than 12 Months, Unrealized Loss	0	0
12 Months or More, Unrealized Loss	(38)	(17)
Unrealized Loss, Total	(38)	(17)
Collateralized mortgage obligations - residential [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	0	0
12 Months or More, Fair Value	1,729	2,083
Total, Fair Value	1,729	2,083
Less than 12 Months, Unrealized Loss	0	0
12 Months or More, Unrealized Loss	(2)	(11)
Unrealized Loss, Total	$ (2)	$ (11)

Securities - Narrative (Details

Securities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Realized gain		$ 3,572	$ 0
Common Class B [Member]
Debt Securities, Available-for-sale [Line Items]
Number of shares sold	25,702
Common Class B [Member] | Visa Inc's Initial Public Offering [Member]
Debt Securities, Available-for-sale [Line Items]
Number of shares sold		51,404
Number of shares remaining	25,702	25,702
Other investments | Fair Value, Measurements, Nonrecurring [Member]
Debt Securities, Available-for-sale [Line Items]
Other investments	$ 3,427	$ 3,427
Fair Value, Inputs, Level 3 [Member] | Other investments | Fair Value, Measurements, Nonrecurring [Member]
Debt Securities, Available-for-sale [Line Items]
Other investments	$ 3,400	$ 3,400

Loans Receivable (Details)

Loans Receivable (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans receivable
Total loans	$ 1,331,194,000	$ 1,321,751,000
Net deferred loan origination costs	1,069,000	1,266,000
Allowance for loan losses	(8,470,000)	(8,366,000)	$ (8,127,000)
Loans, net	1,323,793,000	1,314,651,000
One-to-four family residential real estate loans [Member]
Loans receivable
Total loans	70,371,000	97,814,000
Allowance for loan losses	(699,000)	(850,000)
Multi-family mortgage loans [Member]
Loans receivable
Total loans	619,870,000	588,383,000
Allowance for loan losses	(3,991,000)	(3,849,000)
Nonresidential Real Estate [Member]
Loans receivable
Total loans	152,442,000	169,971,000
Allowance for loan losses	(1,476,000)	(1,605,000)
Construction and land loans [Member]
Loans receivable
Total loans	172,000	1,358,000
Allowance for loan losses	(4,000)	(32,000)
Commercial loans [Member]
Loans receivable
Total loans	187,406,000	152,552,000
Allowance for loan losses	(1,517,000)	(1,357,000)
Commercial leases [Member]
Loans receivable
Total loans	299,394,000	310,076,000
Allowance for loan losses	(755,000)	(655,000)
Consumer loans [Member]
Loans receivable
Total loans	1,539,000	1,597,000
Allowance for loan losses	(28,000)	(18,000)
Nonresidential real estate loans [Member]
Loans receivable
Total loans	$ 152,442,000	$ 169,971,000
No Public Rating [Member] | Maximum [Member] | Commercial leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial Leases, Maturity	5 years
Collateralized Loan [Member] | Multi-family mortgage loans [Member]
Loans receivable
Collateralized Loan Receivable, Percentage Of Collateral Located Outside Primary Market Area	55.00%
Collateralized Loan [Member] | Nonresidential real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Projected Cash Flow To Loan Debt Service Requirement	120.00%
Collateralized Loan [Member] | Maximum [Member] | Multi-family mortgage loans [Member]
Loans receivable
Total loans	$ 5,000,000
Collateralized Loan [Member] | Maximum [Member] | Nonresidential real estate loans [Member]
Loans receivable
Total loans	5,000,000
Collateralized Loan [Member] | Minimum [Member] | Multi-family mortgage loans [Member]
Loans receivable
Total loans	500,000
Collateralized Loan [Member] | Minimum [Member] | Nonresidential real estate loans [Member]
Loans receivable
Total loans	$ 500,000
Mortgage loans above $400,000 [Member] | Collateralized Loan [Member] | Multi-family mortgage loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Projected Cash Flow To Loan Debt Service Requirement	120.00%
Conforming Loans [Member] | $2,500,000 [Member] | Maximum [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages	$ 424,000
Adjustable Rate And Fixed Rate Residential Mortgage [Member] | $2,500,000 [Member] | Maximum [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages	$ 2,500,000
First Mortgage [Member] | Residential Mortgage [Member]
Loans receivable
Percent Threshold On Loan To Value Ratios Requiring Private Mortgage Insurance	80.00%

Loans Receivable - Loan Origina

Loans Receivable - Loan Origination and Risk Management (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 1,331,194,000	$ 1,321,751,000
Maximum [Member] | Finance Leases Financing Receivable [Member] | Investment Grade [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding credit exposure	20,000,000
Multi-family mortgage loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 619,870,000	588,383,000
Multi-family mortgage loans [Member] | Collateralized Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateralized Loan Receivable, Percentage Of Collateral Located Outside Primary Market Area	55.00%
Multi-family mortgage loans [Member] | Collateralized Loan [Member] | Mortgage loans above $400,000 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Projected Cash Flow To Loan Debt Service Requirement	120.00%
Multi-family mortgage loans [Member] | Minimum [Member] | Collateralized Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 500,000
Multi-family mortgage loans [Member] | Maximum [Member] | Collateralized Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 5,000,000
Loan amount as a percentage to value of property collateralized	0.8
Nonresidential real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 152,442,000	169,971,000
Nonresidential real estate loans [Member] | Collateralized Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Projected Cash Flow To Loan Debt Service Requirement	120.00%
Nonresidential real estate loans [Member] | Collateralized Loan [Member] | Fixed Rate Nonresidential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization period	15 years
Nonresidential real estate loans [Member] | Minimum [Member] | Collateralized Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 500,000
Maturity period	3 years
Balloon maturity	3 years
Amortization period	20 years
Nonresidential real estate loans [Member] | Maximum [Member] | Collateralized Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 5,000,000
Loan amount as a percentage to value of property collateralized	0.8
Maturity period	5 years
Balloon maturity	5 years
Amortization period	30 years
Residential mortgage [Member] | Maximum [Member] | Adjustable Rate And Fixed Rate Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maturity period	30 years
Residential mortgage [Member] | Maximum [Member] | $2,500,000 [Member] | Adjustable Rate And Fixed Rate Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages	$ 2,500,000
Residential mortgage [Member] | Maximum [Member] | $2,500,000 [Member] | Conforming Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Face Amount of Mortgages	424,000
Finance Leases Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, amount	$ 299,394,000	$ 310,076,000
Finance Leases Financing Receivable [Member] | Maximum [Member] | No Public Rating [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial Leases, Maturity	5 years
Outstanding credit exposure	$ 10,000,000
Finance Leases Financing Receivable [Member] | Maximum [Member] | Investment Grade [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding credit exposure	$ 10,000,000

Loans Receivable - Allowance fo

Loans Receivable - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	$ 27	$ 0
Collectively evaluated for impairment	8,443	8,366
Allowance for loan losses	8,470	8,366	$ 8,127
Individually evaluated for impairment	3,141	5,214
Collectively evaluated for impairment	1,328,053	1,316,537
Total loans	1,331,194	1,321,751
Net deferred loan origination costs	1,069	1,266
Loans, net	1,323,793	1,314,651
One-to-four family residential real estate loans [Member]
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	699	850
Allowance for loan losses	699	850
Individually evaluated for impairment	2,218	4,265
Collectively evaluated for impairment	68,153	93,549
Total loans	70,371	97,814
Multi-family mortgage loans [Member]
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3,991	3,849
Allowance for loan losses	3,991	3,849
Individually evaluated for impairment	653	949
Collectively evaluated for impairment	619,217	587,434
Total loans	619,870	588,383
Nonresidential Real Estate [Member]
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	27	0
Collectively evaluated for impairment	1,449	1,605
Allowance for loan losses	1,476	1,605
Individually evaluated for impairment	270	0
Collectively evaluated for impairment	152,172	169,971
Total loans	152,442	169,971
Construction and land loans [Member]
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	4	32
Allowance for loan losses	4	32
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	172	1,358
Total loans	172	1,358
Commercial loans [Member]
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	1,517	1,357
Allowance for loan losses	1,517	1,357
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	187,406	152,552
Total loans	187,406	152,552
Commercial leases [Member]
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	755	655
Allowance for loan losses	755	655
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	299,394	310,076
Total loans	299,394	310,076
Consumer loans [Member]
Allowance for loan losses and the loans receivable by portfolio segment
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	28	18
Allowance for loan losses	28	18
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	1,539	1,597
Total loans	$ 1,539	$ 1,597

Loans Receivable - Activity in

Loans Receivable - Activity in the Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				$ 8,366				$ 8,127	$ 8,366	$ 8,127
Loans charged off									(518)	(503)
Recoveries									477	829
Net charge-off									41	(326)
Provision for (recovery of) loan losses	$ 403	$ (23)	$ 23	(258)	$ (72)	$ (225)	$ 49	$ 161	145	(87)
Ending balance	8,470				8,366				8,470	8,366
One-to-four family residential real estate loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				850					850
Loans charged off									(231)	(318)
Recoveries									206	145
Ending balance	699				850				699	850
Multi-family mortgage loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				3,849					3,849
Loans charged off									(35)	(10)
Recoveries									34	70
Ending balance	3,991				3,849				3,991	3,849
Nonresidential real estate loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Loans charged off									(93)	(165)
Recoveries									0	17
Construction and land loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				32					32
Recoveries									2	0
Ending balance	4				32				4	32
Commercial loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				1,357					1,357
Loans charged off									(140)	0
Recoveries									229	594
Ending balance	1,517				1,357				1,517	1,357
Commercial leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				655					655
Recoveries									5	2
Ending balance	755				655				755	655
Consumer loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				$ 18					18
Loans charged off									(19)	(10)
Recoveries									1	1
Ending balance	$ 28				$ 18				$ 28	$ 18

Loans Receivable - Loans Indivi

Loans Receivable - Loans Individually Evaluated for Impairment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Loans individually evaluated for impairment by class loans
Loan Balance	$ 3,491
Recorded Investment	2,854
Partial Charge-off	618
Average Investment in Impaired Loans	4,164
Interest Income Recognized	80
Allowance for loan losses (With an allowance recorded)	27	$ 0
Impaired Loan, Total	3,847	6,007
Recorded Investment, Total	3,124	5,196
Partial Charge-offs, Total	711	806
Average Investment in Impaired Loans, Total	4,185	5,059
Interest Income Recognized, Total	80	238
One-to-four family residential real estate loans [Member]
Loans individually evaluated for impairment by class loans
Loan Balance	2,751	5,049
Recorded Investment	2,155	4,248
Partial Charge-off	575	806
Average Investment in Impaired Loans	3,274	4,212
Interest Income Recognized	41	197
Allowance for loan losses (With an allowance recorded)	0	0
One-to-four family residential real estate loans - non-owner occupied loans [Member]
Loans individually evaluated for impairment by class loans
Loan Balance	86
Recorded Investment	46
Partial Charge-off	43
Average Investment in Impaired Loans	95
Interest Income Recognized	0
Multi-family mortgage loans [Member]
Loans individually evaluated for impairment by class loans
Loan Balance	654	958
Recorded Investment	653	948
Partial Charge-off	0	0
Average Investment in Impaired Loans	795	847
Interest Income Recognized	39	41
Allowance for loan losses (With an allowance recorded)	0	0
Nonresidential real estate loans [Member]
Loans individually evaluated for impairment by class loans
Loan Balance (With an allowance recorded)	356
Recorded Investment (With an allowance recorded)	270
Partial Charge-offs (With an allowance recorded)	93
Allowance for loan losses (With an allowance recorded)	27
Average Investment in Impaired Loans (With an allowance recorded)	21
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0
Consumer loans [Member]
Loans individually evaluated for impairment by class loans
Allowance for loan losses (With an allowance recorded)	$ 0	$ 0

Loans Receivable - Nonaccrual L

Loans Receivable - Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Principal Balance	$ 2,793	$ 4,097
Recorded Investment	1,510	2,390
Loans Past Due Over 90 Days, still accruing	0	0
One-to-four family residential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Principal Balance	2,167	3,413
Recorded Investment	1,162	1,918
Loans Past Due Over 90 Days, still accruing	0	0
One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Principal Balance	270	308
Recorded Investment	78	109
Loans Past Due Over 90 Days, still accruing	0	0
Multi-family mortgage loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Principal Balance		376
Recorded Investment		363
Loans Past Due Over 90 Days, still accruing		$ 0
Nonresidential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Principal Balance	356
Recorded Investment	270
Loans Past Due Over 90 Days, still accruing	$ 0

Loans Receivable - Past Due Loa

Loans Receivable - Past Due Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	$ 4,931	$ 4,451
Recorded investment, loans not past due	1,321,501	1,311,339
Recorded investment, total	1,326,432	1,315,790
One-to-four family residential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	3,179	1,986
Recorded investment, loans not past due	53,820	74,216
Recorded investment, total	56,999	76,202
One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	475	99
Recorded investment, loans not past due	12,460	20,944
Recorded investment, total	12,935	21,043
Multi-family mortgage loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	458	536
Recorded investment, loans not past due	275,283	287,171
Recorded investment, total	275,741	287,707
Wholesale commercial lending [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Recorded investment, loans not past due	340,470	296,440
Recorded investment, total	340,470	296,440
Nonresidential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	270	608
Recorded investment, loans not past due	149,271	166,071
Recorded investment, total	149,541	166,679
Construction loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Recorded investment, loans not past due	0	1,103
Recorded investment, total	0	1,103
Land loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Recorded investment, loans not past due	169	259
Recorded investment, total	169	259
Commercial loans - Secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Recorded investment, loans not past due	39,712	40,935
Recorded investment, total	39,712	40,935
Commercial loans - Unsecured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Commercial Loans - Municipal loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Commercial Loans - Warehouse Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, loans not past due	62,719	40,237
Recorded investment, total	62,719	40,237
Commercial Loans - Health Care [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, loans not past due	85,418	71,738
Recorded investment, total	85,418	71,738
Commercial Leases - Investment rated commercial leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	505	934
Recorded investment, loans not past due	166,713	207,747
Recorded investment, total	167,218	208,681
Commercial Leases - Below Investment Grade [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	288
Recorded investment, loans not past due	133,958	102,873
Recorded investment, total	133,958	103,161
Consumer loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	44	0
Recorded investment, loans not past due	1,508	1,605
Recorded investment, total	1,552	1,605
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	2,770	2,098
30-59 Days Past Due [Member] | One-to-four family residential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	1,380	86
30-59 Days Past Due [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	387	10
30-59 Days Past Due [Member] | Multi-family mortgage loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	458	172
30-59 Days Past Due [Member] | Wholesale commercial lending [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
30-59 Days Past Due [Member] | Nonresidential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	608
30-59 Days Past Due [Member] | Construction loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
30-59 Days Past Due [Member] | Land loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
30-59 Days Past Due [Member] | Commercial loans - Secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
30-59 Days Past Due [Member] | Commercial Loans - Municipal loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
30-59 Days Past Due [Member] | Commercial Loans - Warehouse Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
30-59 Days Past Due [Member] | Commercial Leases - Investment rated commercial leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	505	934
30-59 Days Past Due [Member] | Commercial Leases - Below Investment Grade [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	288
30-59 Days Past Due [Member] | Consumer loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	40	0
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	921	102
60-89 Days Past Due [Member] | One-to-four family residential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	637	99
60-89 Days Past Due [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	10	3
60-89 Days Past Due [Member] | Multi-family mortgage loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Wholesale commercial lending [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Nonresidential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	270	0
60-89 Days Past Due [Member] | Construction loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Land loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Commercial loans - Secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Commercial Loans - Municipal loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Commercial Loans - Warehouse Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Commercial loans - Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Commercial Leases - Investment rated commercial leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
60-89 Days Past Due [Member] | Consumer loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	4	0
90 Days or Greater Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	1,240	2,251
90 Days or Greater Past Due [Member] | One-to-four family residential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	1,162	1,801
90 Days or Greater Past Due [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	78	86
90 Days or Greater Past Due [Member] | Multi-family mortgage loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	364
90 Days or Greater Past Due [Member] | Wholesale commercial lending [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Nonresidential real estate loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Construction loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Land loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Commercial loans - Secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Commercial Loans - Municipal loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Commercial Loans - Warehouse Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Commercial Loans - Health Care [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Commercial loans - Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Commercial Leases - Investment rated commercial leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
90 Days or Greater Past Due [Member] | Consumer loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	$ 0	$ 0

Loans Receivable - Aging of Rec

Loans Receivable - Aging of Recorded Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	$ 4,931	$ 4,451
Recorded Investment, Loans Not Past Due	1,321,501	1,311,339
One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	475	99
Recorded Investment, Loans Not Past Due	12,460	20,944
Multi-family mortgage loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	458	536
Recorded Investment, Loans Not Past Due	275,283	287,171
Construction loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Recorded Investment, Loans Not Past Due	0	1,103
Land loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Recorded Investment, Loans Not Past Due	169	259
Commercial loans - Secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	0	0
Recorded Investment, Loans Not Past Due	39,712	40,935
Commercial loans - Unsecured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment, Total Past Due	$ 0	$ 0

Loans Receivable - Troubled Deb

Loans Receivable - Troubled Debt Restructuring (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Troubled Debt Restructurings
Financing receivable modifications	$ 17,000	$ 17,000
Non Accrual Loans [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Troubled Debt Restructurings
Financing receivable modifications	$ 17,000	$ 17,000

Loans Receivable - Credit Quali

Loans Receivable - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable Credit Quality Indicators
Total loans	$ 1,331,194	$ 1,321,751
One-to-four family residential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	70,371	97,814
One to Four Family Residential Real Estate Loans-Owner occupied [Member] [Member]
Financing Receivable Credit Quality Indicators
Total loans	57,169	76,606
One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	13,202	21,208
Multi-family mortgage loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	619,870	588,383
Multi Family Mortgage Loans excluding wholesale [Member] [Member]
Financing Receivable Credit Quality Indicators
Total loans	279,237	291,358
Wholesale commercial lending [Member]
Financing Receivable Credit Quality Indicators
Total loans	340,633	297,025
Nonresidential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	152,442	169,971
Construction loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	1,099
Land loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	172	259
Commercial loans - Secured [Member]
Financing Receivable Credit Quality Indicators
Total loans	39,574	40,901
Commercial loans - Unsecured [Member]
Financing Receivable Credit Quality Indicators
Total loans	85,343	71,728
Commercial Loans - Municipal loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	62,489	39,923
Commercial Leases - Investment Rated [Member]
Financing Receivable Credit Quality Indicators
Total loans	166,209	207,460
Commercial Leases - Below Investment Grade [Member]
Financing Receivable Credit Quality Indicators
Total loans	133,185	102,616
Consumer loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	1,539	1,597
Nonaccrual [Member]
Financing Receivable Credit Quality Indicators
Total loans	1,517	2,391
Nonaccrual [Member] | One-to-four family residential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	993	1,914
Nonaccrual [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	254	109
Nonaccrual [Member] | Multi-family mortgage loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	368
Nonaccrual [Member] | Wholesale commercial lending [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Nonresidential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	270	0
Nonaccrual [Member] | Construction loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Land loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Commercial loans - Secured [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Commercial loans - Unsecured [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Commercial Loans - Municipal loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Commercial Leases - Investment Rated [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Commercial Leases - Below Investment Grade [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Nonaccrual [Member] | Consumer loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member]
Financing Receivable Credit Quality Indicators
Total loans	6,290	4,528
Special Mention [Member] | One-to-four family residential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	495	0
Special Mention [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Multi-family mortgage loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Wholesale commercial lending [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Nonresidential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	281	0
Special Mention [Member] | Construction loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Land loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Commercial loans - Secured [Member]
Financing Receivable Credit Quality Indicators
Total loans	4,810	4,528
Special Mention [Member] | Commercial loans - Unsecured [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Commercial Loans - Municipal loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Commercial Leases - Investment Rated [Member]
Financing Receivable Credit Quality Indicators
Total loans	701	0
Special Mention [Member] | Commercial Leases - Below Investment Grade [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Special Mention [Member] | Consumer loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	3	0
Substandard [Member]
Financing Receivable Credit Quality Indicators
Total loans	1,028	2,922
Substandard [Member] | One-to-four family residential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	328	255
Substandard [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	37	40
Substandard [Member] | Multi-family mortgage loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	216	225
Substandard [Member] | Wholesale commercial lending [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Substandard [Member] | Nonresidential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	98	154
Substandard [Member] | Construction loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Substandard [Member] | Land loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Substandard [Member] | Commercial loans - Secured [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Substandard [Member] | Commercial loans - Unsecured [Member]
Financing Receivable Credit Quality Indicators
Total loans	342	2,248
Substandard [Member] | Commercial Loans - Municipal loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Substandard [Member] | Commercial Leases - Investment Rated [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Substandard [Member] | Commercial Leases - Below Investment Grade [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	0
Substandard [Member] | Consumer loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	7	0
Pass [Member]
Financing Receivable Credit Quality Indicators
Total loans	1,322,359	1,311,910
Pass [Member] | One-to-four family residential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	55,353	74,437
Pass [Member] | One-to-four family residential real estate loans - non-owner occupied loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	12,911	21,059
Pass [Member] | Multi-family mortgage loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	279,021	290,765
Pass [Member] | Wholesale commercial lending [Member]
Financing Receivable Credit Quality Indicators
Total loans	340,633	297,025
Pass [Member] | Nonresidential real estate loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	151,793	169,817
Pass [Member] | Construction loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	0	1,099
Pass [Member] | Land loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	172	259
Pass [Member] | Commercial loans - Secured [Member]
Financing Receivable Credit Quality Indicators
Total loans	34,764	36,373
Pass [Member] | Commercial loans - Unsecured [Member]
Financing Receivable Credit Quality Indicators
Total loans	85,001	69,480
Pass [Member] | Commercial Loans - Municipal loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	62,489	39,923
Pass [Member] | Commercial Leases - Investment Rated [Member]
Financing Receivable Credit Quality Indicators
Total loans	165,508	207,460
Pass [Member] | Commercial Leases - Below Investment Grade [Member]
Financing Receivable Credit Quality Indicators
Total loans	133,185	102,616
Pass [Member] | Consumer loans [Member]
Financing Receivable Credit Quality Indicators
Total loans	$ 1,529	$ 1,597

Loans Receivable - Narrative (D

Loans Receivable - Narrative (Details)	12 Months Ended
	Dec. 31, 2018USD ($)contract	Dec. 31, 2017USD ($)contract
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation of reserves allocation	$ 23,000	$ 261,000
Reserve For Uncollected Loan Interest	38,000	103,000
Financing receivable modifications	17,000	17,000
Outstanding Commitments To Borrowers Loans Classified As Troubled Debt Restructurings	$ 0
Increased value of allowances for loan losses		$ 0
Number of loans modified and classified as TDRs | contract	0	0
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation of reserves allocation	$ 0	$ 0

Other Real Estate (Details)

Other Real Estate (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Real Estate, Disposals	$ (2,580,000)	$ (3,977,000)
other real estate owned at carrying value before valuation allowance	1,249,000	2,656,000
Real Estate Owned, Valuation Allowance	(23,000)	(305,000)	$ (449,000)
New foreclosed properties	1,482,000	2,766,000
Other Real Estate, Valuation Adjustments	(27,000)	(333,000)
Real Estate Owned, Valuation Allowance, Valuation Increase	27,000	333,000
reduction in valuation allowance for sales of OREO	(309,000)	(477,000)
Other Real Estate Owned At Carrying Value	1,226,000	2,351,000	$ 3,895,000
Mortgage Loans in Process of Foreclosure, Amount	300,000	900,000
One to Four Family Residential Real Estate Loans [Member]
other real estate owned at carrying value before valuation allowance	875,000	836,000
Real Estate Owned, Valuation Allowance	0	(9,000)
Other Real Estate Owned At Carrying Value	875,000	827,000
Multi Family Mortgage Loans [Member]
other real estate owned at carrying value before valuation allowance	276,000	0
Real Estate Owned, Valuation Allowance	0	0
Other Real Estate Owned At Carrying Value	276,000	0
Nonresidential Real Estate [Member]
other real estate owned at carrying value before valuation allowance	74,000	1,772,000
Real Estate Owned, Valuation Allowance	0	(252,000)
Other Real Estate Owned At Carrying Value	74,000	1,520,000
Land [Member]
other real estate owned at carrying value before valuation allowance	24,000	48,000
Real Estate Owned, Valuation Allowance	(23,000)	(44,000)
Other Real Estate Owned At Carrying Value	1,000	4,000
Residential Real Estate [Member]
Repossessed assets	$ 0	$ 352,000

Premises and Equipment - Year E

Premises and Equipment - Year End (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 57,232,000	$ 55,482,000
Accumulated depreciation	(32,027,000)	(30,626,000)
Property and equipment, net	25,205,000	24,856,000
Depreciation	1,500,000	2,000,000
Premises held-for-sale	0	5,667,000
Gain on sale of premises held-for-sale	93,000	0
Land and land improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	12,359,000	12,265,000
Building and building improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	30,602,000	29,556,000
Furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,039,000	9,678,000
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4,232,000	$ 3,983,000

Premises and Equipment - Schedu

Premises and Equipment - Schedule of Future Minimum Payments for Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant, Equipment And Leases [Abstract]
Rent expense, net of sublease income	$ 958	$ 477
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,017	927
2,018	894
2,019	913
2,020	952
2,021	939
Thereafter	3,250
Total	$ 7,875

Core Deposit Intangible - Sched

Core Deposit Intangible - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Finite-lived Intangible Assets [Roll Forward]
Amortization	$ (184)	$ (496)
Core Deposits [Member]
Finite-lived Intangible Assets [Roll Forward]
Balance at the beginning of the year	782	1,305
Amortization	(496)	(523)	$ (550)
Additions	0	0
Net Carrying Value	$ 782	$ 1,305	$ 1,305	$ 286	$ 782
Gross carrying amount				5,932	5,932
Accumulated amortization				$ (5,646)	$ (5,150)

Core Deposit Intangible - Sch_2

Core Deposit Intangible - Schedule of Finite-Lived Intangible Assets Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	$ 184	$ 496
Core Deposits [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangibles	496	$ 523	$ 550
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,015	184
2,016	61
2,017	34
2,018	7
2,019	$ 0

Deposits - Schedule of Deposits

Deposits - Schedule of Deposits By Type (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Noninterest-bearing demand deposits	$ 230,041	$ 234,354
Interest-bearing NOW accounts	275,830	289,657
Money market accounts	255,951	299,581
Savings deposits	152,334	160,501
Time Deposits	$ 438,328	$ 355,958

Deposits - Time Deposits, By Ma

Deposits - Time Deposits, By Maturity (Details) $ in Thousands	Dec. 31, 2018USD ($)
Deposits [Abstract]
2,017	$ 290,219
2,018	125,991
2,019	17,359
2,020	3,231
2,021	$ 1,528

Deposits - Narrative (Details)

Deposits - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Time deposits, $100,000 or more	$ 81.5	$ 50.3

Securities Sold Under Agreeme_3

Securities Sold Under Agreement to Repurchase Securities Sold Under Agreement to Repurchase (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Federal Home Loan Bank, Advances [Line Items]
Repurchase agreements and repurchase-to-maturity transactions	$ 1,049	$ 768
Federal Home Loan Bank Advances [Member] | Within 1 year [Member]
Federal Home Loan Bank, Advances [Line Items]
Borrowings, Amount	20,000	60,000
Overnight and Continuous
Federal Home Loan Bank, Advances [Line Items]
Repurchase agreements and repurchase-to-maturity transactions	1,049	768
Up to 30 days
Federal Home Loan Bank, Advances [Line Items]
Repurchase agreements and repurchase-to-maturity transactions	0	0
30 - 90 days
Federal Home Loan Bank, Advances [Line Items]
Repurchase agreements and repurchase-to-maturity transactions	0	0
Greater Than 90 days
Federal Home Loan Bank, Advances [Line Items]
Repurchase agreements and repurchase-to-maturity transactions	0	0
Collateral Pledged [Member]
Federal Home Loan Bank, Advances [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 2,700	$ 3,700

Federal Home Loan Bank Advanc_3

Federal Home Loan Bank Advances (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
First Mortgage [Member]
Debt Instrument [Line Items]
Collateral	$ 46,900,000
Multi-family mortgage loans [Member]
Debt Instrument [Line Items]
Collateral	$ 358,900,000
Federal Home Loan Bank Advances [Member] | Within 1 year [Member]
Debt Instrument [Line Items]
Borrowings, Contractual Rate	2.51%	1.34%
Borrowings, Amount	$ 20,000,000	$ 60,000,000
Federal Home Loan Bank Borrowings [Member]
Debt Instrument [Line Items]
Increase in line of credit	311,800,000
Letter of Credit [Member] | Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Outstanding balance	$ 0	$ 0

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current benefit									$ 378	$ (2,658)
Deferred benefit									6,328	7,361
Deferred tax valuation allowance									0	2,487
Total income tax expense (benefit)	$ 2,803	$ 1,396	$ 1,207	$ 1,300	$ 4,702	$ 594	$ 1,572	$ 322	$ 6,706	$ 7,190

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Benefit computed at the statutory federal tax rate									$ 5,470	$ 5,506
State taxes and other, net									1,564	(204)
Bank owned life insurance									(328)	(90)
ESOP/Share based compensation									0	(509)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount					$ 2,500				0	2,487
Total income tax expense (benefit)	$ 2,803	$ 1,396	$ 1,207	$ 1,300	$ 4,702	$ 594	$ 1,572	$ 322	$ 6,706	$ 7,190
Effective income tax rate									25.74%	44.77%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Gross Deferred tax assets:
Allowance for loan losses	$ 2,279	$ 2,258
Alternative minimum tax, general business credit and net operating loss carryforward	6,669	11,864
Tax deductible goodwill	561	801
Other	1,256	1,395
Total deferred tax assets, gross	10,765	16,318
Gross Deferred tax liabilities:
Net deferred loan origination costs	(1,186)	(1,255)
Purchase accounting adjustments	(1,673)	(1,744)
Other	(649)	(619)
Unrealized gain on securities	(1,022)	(137)
Gross deferred tax liabilities:	(4,530)	(3,755)
Net deferred tax asset	$ 6,235	$ 12,563

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Balances Roll-forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning of year	$ 129	$ 57
Additions based on tax positions related to the current year	85	60
Additions for tax positions of prior years	4	12
Reductions due to the statute of limitations	(20)	0
End of year	$ 198	$ 129

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax not recongized	$ 14,900	$ 14,900	$ 14,900
Deferred Tax Assets, Net	12,563	6,235	12,563
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	2,500	$ 0	2,487
Reclassification for the Tax Cuts and Jobs Act				$ 0
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification for the Tax Cuts and Jobs Act				(60)
Retained Earnings | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification for the Tax Cuts and Jobs Act	(60,000)		(60,000)
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification for the Tax Cuts and Jobs Act				$ 60
Accumulated Other Comprehensive Income (Loss) | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification for the Tax Cuts and Jobs Act	$ 60,000		$ 60,000

Income Taxes - Narrative Tax Ca

Income Taxes - Narrative Tax Carryforwards (Details) $ in Millions	Dec. 31, 2018USD ($)
Alternative Minimum Tax Carryforward Axis [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 3.1
Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	1.2
Tax credit carryforward	1.3
State and Local Jurisdiction [Member]
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	58.5
Downers Grove National Bank [Member]
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 7.5

Regulatory Matters - Requiremen

Regulatory Matters - Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Risk Based Ratios [Abstract]
Common Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets		4.50%
Consolidated Entities [Member]
Capital [Abstract]
Total capital (to risk-weighted assets), Actual, Amount		$ 195,371
Total capital (to risk-weighted assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		91,590
Tier One Risk Based Capital [Abstract]
Tier 1 (core) capital (to risk-weighted assets), Actual, Amount		187,005
Tier 1 (core) capital (to risk-weighted assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		68,692
Tier One Leverage Capital [Abstract]
Tier 1 (core) capital (to adjusted average total assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount		$ 65,085
Risk Based Ratios [Abstract]
Total capital (to risk-weighted assets), Actual, Ratio		17.06%
Total capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio		8.00%
Tier 1 (core) capital (to risk-weighted assets), Actual, Ratio		16.33%
Tier 1 (core) capital (to risk-weighted assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio		6.00%
CET common tier 1 equity		$ 187,005
Common Tier 1 to Risk Weighted Assets		16.33%
Common Tier 1 Risk Based Capital Required for Capital Adequacy		$ 51,519
Leverage Ratios [Abstract]
Tier 1 (core) capital (to adjusted average total assets), Actual, Ratio		11.49%
Tier 1 (core) capital (to adjusted average total assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio		4.00%
BankFinancial NA [Member]
Capital [Abstract]
Total capital (to risk-weighted assets), Actual, Amount	$ 178,664	$ 188,582
Total capital (to risk-weighted assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	93,430	91,572
Total capital (to risk-weighted assets), Minimum Capital Ratios Established under Capital Plans, Amount	116,787	114,466
Tier One Risk Based Capital [Abstract]
Tier 1 (core) capital (to risk-weighted assets), Actual, Amount	170,194	180,216
Tier 1 (core) capital (to risk-weighted assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	70,072	68,679
Tier 1 (core) capital (to risk-weighted assets), Minimum Capital Ratios Established under Capital Plans, Amount	93,430	91,572
Tier One Leverage Capital [Abstract]
Tier 1 (core) capital (to adjusted average total assets), Actual, Amount	170,194	180,216
Tier 1 (core) capital (to adjusted average total assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	61,721	65,045
Tier 1 (core) capital (to adjusted average total assets), Minimum Capital Ratios Established under Capital Plans, Amount	$ 77,151	$ 81,307
Risk Based Ratios [Abstract]
Total capital (to risk-weighted assets), Actual, Ratio	15.30%	16.48%
Total capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total capital (to risk-weighted assets), Minimum Capital Ratios Established under Capital Plans, Ratio	10.00%	10.00%
Tier 1 (core) capital (to risk-weighted assets), Actual, Ratio	14.57%	15.74%
Tier 1 (core) capital (to risk-weighted assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.00%	6.00%
Tier 1 (core) capital (to risk-weighted assets), Minimum Capital Ratios Established under Capital Plans, Ratio	8.00%	8.00%
CET common tier 1 equity	$ 170,194	$ 180,216
Common Tier 1 to Risk Weighted Assets	14.57%	15.74%
Common Tier 1 Risk Based Capital Required for Capital Adequacy	$ 52,554	$ 51,509
Common Tier 1 Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.50%	4.50%
Common Tier One Capital required to be well capitalized	$ 75,912	$ 74,403
Common Tier One Risk Weighted Assets Required to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Leverage Ratios [Abstract]
Tier 1 (core) capital (to adjusted average total assets), Actual, Ratio	11.03%	11.08%
Tier 1 (core) capital (to adjusted average total assets), Minimum required To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	4.00%	4.00%
Tier 1 (core) capital (to adjusted average total assets), Minimum Capital Ratios Established under Capital Plans, Ratio	5.00%	5.00%

Regulatory Matters - Narrative

Regulatory Matters - Narrative (Details) $ in Millions	Dec. 31, 2018USD ($)
Minimum [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash to be held	$ 5

Employee Benefit Plans - Employ

Employee Benefit Plans - Employee Stock Ownership Plan (Details) - USD ($)	Mar. 29, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 23, 2005
Compensation Related Costs, Retirement and Share Based Payment [Line Items]
ESOP compensation expense		$ 1,100,000		$ 1,100,000
Loan receivable from ESOP					$ 19,600,000
ESOP issued price (usd per share)			$ 10
ESOP cash contributions			$ 0	1,100,000
ESOP, dividends and interest received				$ 50,000
Employee Stock Ownership Plan (ESOP), Shares in ESOP [Abstract]
Allocated to participants (shares)			885,896	1,203,810
Distributed to participants			(885,896)	(317,914)
Total ESOP shares (shares)	78,362		0	885,896
Common Stock [Member]
Compensation Related Costs, Retirement and Share Based Payment [Line Items]
Repayments of Debt, Equity Instrument Consideration, Shares Issued	753,490
ESOP shares purchased (shares)			1,957,300
Share Acquisition Loan [Member]
Compensation Related Costs, Retirement and Share Based Payment [Line Items]
Loans Payable			$ 0	$ 0

Employee Benefit Plans - Empl_2

Employee Benefit Plans - Employee Stock Ownership Plan - Profit Sharing 401(k) Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Age for eligibility for Employee Benefits	21 years
Employee benefit plans, requisite time for service	1 year
Employee matching ratio	50.00%
Maximum annual contribution per employee	6.00%
Contribution plan expenses	$ 506	$ 328

Equity Incentive Plans - Narrat

Equity Incentive Plans - Narrative (Details) - USD ($)	Jun. 27, 2006	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock available for grant		0
Stock Options Outstanding (in shares)		0	1,752,156	1,752,156
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		0	0
Share-based compensation expense		$ 0	$ 0
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized		$ 0
Stock options granted (in shares)		0
Share-based Compensation Arrangement by Share-based Payment Award, Net Settlement Share Issuance		280,554
Share-based Compensation Arrangement by Share-based Payment Award, Shares Withheld For Taxes		82,528
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period		198,026
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms		0 days		8 months 27 days
Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		5 years
2006 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (shares)	3,425,275
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years

Equity Incentive Plans - Schedu

Equity Incentive Plans - Schedule of Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Stock options outstanding (in shares)	1,752,156	1,752,156
Stock options granted (in shares)	0
Stock options exercised (in shares)	(1,752,156)	(198,026)
Stock options exercised (in shares)	0	1,752,156
Weighted Average Exercise Price
Stock options outstanding, beginning balance (in usd per share)	$ 12.30
Stock options granted (in usd per share)	0
Stock options exercised (in usd per share)	12.30
Stock options outstanding, ending balance (in usd per share)	$ 0	$ 12.30
Stock options outstanding, weighted average remaining contractual term	1 day	5 months 23 days
Stock options outstanding, aggregate intrinsic value	$ 0	$ 4,422

Equity Incentive Plans - Sche_2

Equity Incentive Plans - Schedule of Restricted Stock Activity (Details) - Restricted Stock [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares outstanding, beginning balance (shares)	940	940
Shares granted (shares)	0	0
Shares vested (shares)	(694)	0
Shares forfeited (shares)	(246)	0
Shares outstanding, ending balance (shares)	0	940	940
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Shares outstanding, beginning balance, Weighted Average Fair Value at Grant Date (usd per share)	$ 8.14	$ 8.14
Shares granted, Weighted Average Fair Value at Grant Date (usd per share)	0	0
Shares vested, Weighted Average Fair Value at Grant Date (usd per share)	8.14	0
Shares forfeited, Weighted Average Fair Value at Grant Date (usd per share)	8.14	0
Shares outstanding, ending balance, Weighted Average Fair Value at Grant Date (usd per share)	$ 0	$ 8.14	$ 8.14
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	0 days		8 months 27 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding	$ 0	$ 14	$ 14

Loan Commitments and Other Of_3

Loan Commitments and Other Off-Balance Sheet Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Guarantor Obligations [Line Items]
Duration of extension	60 days
Commitments to extend credit [Member]
Guarantor Obligations [Line Items]
Notional Or Contractual Credit Extension Commitments	$ 75,180	$ 46,615
Fixed-rate loan commitments	44,500
Standby letters of credit [Member]
Guarantor Obligations [Line Items]
Notional Or Contractual Credit Extension Commitments	5,965	6,757
Unused lines of credit [Member]
Guarantor Obligations [Line Items]
Notional Or Contractual Credit Extension Commitments	152,554	129,207
Commitments to sell mortgages [Member]
Guarantor Obligations [Line Items]
Notional Or Contractual Credit Extension Commitments	$ 0	$ 0
Minimum [Member] | Commitments to extend credit [Member]
Guarantor Obligations [Line Items]
Fixed interest rate	4.12%
Maturity period	1 year
Maximum [Member] | Commitments to extend credit [Member]
Guarantor Obligations [Line Items]
Fixed interest rate	7.00%
Maturity period	30 years

Fair Value - Financial Assets A

Fair Value - Financial Assets Accounted for at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	$ 88,179	$ 93,383
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value	73,507
Certificates of deposit [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	73,507	75,916
Equity Funds [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	499
Residential Mortgage Backed Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	10,478	12,472
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	10,478
Collateralized Debt Obligations [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	3,685	4,486
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	3,685
SBA-guaranteed loan participation certificates [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale		10
Municipal Bonds [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	509
Nonrecurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	88,179	93,383
Nonrecurring [Member] | Certificates of deposit [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	73,507	75,916
Nonrecurring [Member] | Equity mutual fund [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale		499
Nonrecurring [Member] | Mortgage-backed securities - residential [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	10,478	12,472
Nonrecurring [Member] | Collateralized mortgage obligations - residential [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	3,685	4,486
Nonrecurring [Member] | SBA-guaranteed loan participation certificates [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale		10
Nonrecurring [Member] | Municipal Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	509
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	499
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Certificates of deposit [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage-backed securities - residential [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Collateralized mortgage obligations - residential [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | SBA-guaranteed loan participation certificates [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale		0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Municipal Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0
Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	88,179	92,884
Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member] | Equity mutual fund [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale		0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Certificates of deposit [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity mutual fund [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale		0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage-backed securities - residential [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Collateralized mortgage obligations - residential [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0	0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | SBA-guaranteed loan participation certificates [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale		0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Municipal Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	0
Estimate of Fair Value Measurement [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	88,179	93,383
Estimate of Fair Value Measurement [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	88,179	92,884
Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Available-for-sale	$ 0	$ 0

Fair Value - Assets Measured at

Fair Value - Assets Measured at Fair Value on a Non-Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned	$ 0	$ 900
Mortgage servicing rights	420	513
Nonrecurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned		916
Nonrecurring [Member] | One-to-four family residential real estate loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned		102
Nonrecurring [Member] | Nonresidential real estate loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Impaired loans	270
Fair Value, Other real estate owned		814
Nonrecurring [Member] | Land loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned	1
Nonrecurring [Member] | Other investments
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	3,427
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned		0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | One-to-four family residential real estate loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned		0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonresidential real estate loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Impaired loans	0
Fair Value, Other real estate owned		0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Land loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned	0
Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other investments
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	0
Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned		0
Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member] | One-to-four family residential real estate loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned		0
Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member] | Nonresidential real estate loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Impaired loans	0
Fair Value, Other real estate owned		0
Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member] | Land loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned	0
Nonrecurring [Member] | Significant Observable Inputs (Level 2) [Member] | Other investments
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	0
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned		$ 916
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Nonresidential real estate loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Impaired loans	270
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Land loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Other real estate owned	1
Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other investments
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other investments	$ 3,400

Fair Value - Level 3 Fair Value

Fair Value - Level 3 Fair Value Measurements for Financial Instruments on a Non-recurring Basis (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	$ 88,179	$ 93,383
Fair Value, Other real estate owned	0	900
Fair value of mortgage servicing rights	$ 420	513
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Other real estate owned		$ 916
One to Four Family Residential Real Estate Loans [Member] | Sales comparison [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description		Sales comparison
Fair Value Measurements, Sensitivity Analysis, Description		Discount applied to valuation
Nonresidential real estate loans [Member] | Sales comparison [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description		Sales comparison
Fair Value Measurements, Sensitivity Analysis, Description		Comparison between sales and income approaches
Land [Member] | Sales comparison [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description	Sales comparison
Fair Value Measurements, Sensitivity Analysis, Description	Discount applied to valuation
Land [Member] | Sales comparison [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned, Measurement Input	0.123
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	$ 88,179	$ 93,383
Fair Value, Other real estate owned		916
Fair Value, Measurements, Nonrecurring [Member] | One to Four Family Residential Real Estate Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Other real estate owned		102
Fair Value, Measurements, Nonrecurring [Member] | Nonresidential real estate loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Impaired loans	270
Fair Value, Other real estate owned		814
Fair Value, Measurements, Nonrecurring [Member] | Land [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Other real estate owned	1
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Fair Value, Other real estate owned		916
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] | One to Four Family Residential Real Estate Loans [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Other real estate owned		102
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Nonresidential real estate loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Impaired loans	270
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Nonresidential real estate loans [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Other real estate owned		$ 814
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Land [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Other real estate owned	$ 1
Measurement Input, Discount Rate [Member] | One to Four Family Residential Real Estate Loans [Member] | Sales comparison [Member] | Weighted Average [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned, Measurement Input	0.0560
Measurement Input, Comparability Adjustment [Member] | Nonresidential real estate loans [Member] | Sales comparison [Member] | Minimum [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned, Measurement Input	0.1522
Measurement Input, Comparability Adjustment [Member] | Nonresidential real estate loans [Member] | Sales comparison [Member] | Maximum [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned, Measurement Input	(0.0366)
Measurement Input, Comparability Adjustment [Member] | Nonresidential real estate loans [Member] | Sales comparison [Member] | Weighted Average [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned, Measurement Input	(0.1100)

Fair Value - Carrying Amount an

Fair Value - Carrying Amount and Estimated Fair Value of Finanical Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	$ (23)	$ (261)
Fair value of mortgage servicing rights	420	513
Financial assets
Cash and cash equivalents, carrying amount	98,204	127,592	$ 96,684
Cash and Due from Banks	13,805	13,572
Interest-bearing Deposits in Banks and Other Financial Institutions	84,399	114,020
Marketable Securities	88,179	93,383
Securities, carrying amount	88,179	93,383
Loans receivable, net of allowance for loan losses, carrying amounts	1,323,793	1,314,651
FHLBC stock, carrying amount	8,026	8,290
Accrued interest receivable, carrying amount	4,952	4,619
Financial liabilities
Noninterest-bearing demand deposits	230,041	234,354
Savings deposits	152,334	160,501
Time Deposits	438,328	355,958
Borrowings	21,049	60,768
Carrying Amount [Member]
Financial liabilities
NOW and money market accounts, carrying amount	531,781	589,238
Accrued interest payable, carrying amount	291	147
Estimated Fair Value [Member]
Financial assets
Cash and cash equivalents, fair value	98,204	127,592
Securities, carrying amount	88,179	93,383
Loans receivable, net of allowance for loan losses, fair value	1,315,855	1,323,139
Accounts interest receivable, fair value	4,952	4,619
Financial liabilities
Non-interest-bearing demand deposits, fair value	230,041	234,354
NOW money market accounts, fair value	531,781	589,238
Savings deposits, fair value	152,334	160,501
Certificates of deposit, fair value	436,598	353,969
Borrowings, fair value	21,050	60,627
Accrued interest payable, fair value	291	147
Estimated Fair Value [Member] | Fair Value, Inputs, Level 1 [Member]
Financial assets
Loans receivable, net of allowance for loan losses, fair value	0	0
Accounts interest receivable, fair value	0	0
Financial liabilities
Non-interest-bearing demand deposits, fair value	0	0
Savings deposits, fair value	0	0
Certificates of deposit, fair value	0	0
Borrowings, fair value	0	0
Accrued interest payable, fair value	0	0
Estimated Fair Value [Member] | Level 2 [Member]
Financial assets
Securities, carrying amount	88,179	92,884
Loans receivable, net of allowance for loan losses, fair value	0	1,323,139
Accounts interest receivable, fair value	249	4,619
Financial liabilities
Non-interest-bearing demand deposits, fair value	230,041	234,354
NOW money market accounts, fair value	531,781	589,238
Savings deposits, fair value	152,334	160,501
Certificates of deposit, fair value	436,598	353,969
Borrowings, fair value	21,050	60,627
Accrued interest payable, fair value	291	147
Estimated Fair Value [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets
Cash and cash equivalents, fair value	0	0
Securities, carrying amount	0	0
Loans receivable, net of allowance for loan losses, fair value	1,315,855	0
Accounts interest receivable, fair value	4,703	0
Financial liabilities
Non-interest-bearing demand deposits, fair value	0	0
Savings deposits, fair value	0	0
Certificates of deposit, fair value	0	0
Borrowings, fair value	0	0
Accrued interest payable, fair value	0	0
Equity Funds [Member]
Financial assets
Securities, carrying amount	0	499
Fair Value, Measurements, Nonrecurring [Member]
Financial assets
Securities, carrying amount	88,179	93,383
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial assets
Securities, carrying amount	0	499
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Financial assets
Securities, carrying amount	88,179	92,884
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets
Securities, carrying amount	0	0
Fair Value, Measurements, Nonrecurring [Member] | Collateralized Mortgage Obligations Residential [Member]
Financial assets
Securities, carrying amount	3,685	4,486
Fair Value, Measurements, Nonrecurring [Member] | Collateralized Mortgage Obligations Residential [Member] | Fair Value, Inputs, Level 1 [Member]
Financial assets
Securities, carrying amount	0	0
Fair Value, Measurements, Nonrecurring [Member] | Collateralized Mortgage Obligations Residential [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets
Securities, carrying amount	$ 0	$ 0

Fair Value - Narratives (Detail

Fair Value - Narratives (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans carrying amount	$ 270,000
other real estate owned with an allowance at carrying value before valuation allowance	0	$ 1,200,000
Impaired loans, valuation allowance	27,000
Provision for Loan and Lease Losses	0	26,000
Other real estate owned at carrying value	1,226,000	2,351,000	$ 3,895,000
Real Estate Acquired Through Foreclosure Fair Value	0	900,000
Real Estate Owned, Valuation Allowance, Valuation Increase	27,000	333,000
Other Real Estate, Valuation Adjustments	27,000	333,000
Fair value of mortgage servicing rights	$ 420,000	513,000
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real Estate Acquired Through Foreclosure Fair Value		916,000
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real Estate Acquired Through Foreclosure Fair Value		$ 916,000

Revenue From Contracts With C_3

Revenue From Contracts With Customers (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Revenue from External Customer [Line Items]
Deposit service charges and fees									$ 3,968,000	$ 3,953,000
Loan servicing fees									439,000	326,000
Commerical mortgage brokerage fees									138,000	0
Mortgage brokerage and banking fees									119,000	215,000
Gain on sale of equity securities									3,558,000	0
Unrealized gains on equity securities									3,427,000	0
Gain on sale of premises held-for-sale									93,000	0
Earnings on bank-owned life insurance									174,000	265,000
Bank-owned life insurance death benefit									1,389,000	0
Other									635,000	678,000
Total noninterest income	$ 8,674,000	$ 1,570,000	$ 3,094,000	$ 1,539,000	$ 1,634,000	$ 1,623,000	$ 1,607,000	$ 1,544,000	14,877,000	6,408,000
Bank Servicing [Member]
Revenue from External Customer [Line Items]
Trust and insurance commissions and annuities income									937,000	971,000
Credit and Debit Card
Revenue from External Customer [Line Items]
Deposit service charges and fees									$ 1,500,000	$ 1,400,000

Company Only Condensed Financ_3

Company Only Condensed Financial Information - Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Deferred Tax Assets, Net	$ 6,235	$ 12,563
Other assets	10,594	8,441
Total assets	1,585,325	1,625,558
Liabilities and Stockholders' Equity
Total stockholders’ equity	187,150	197,634	$ 204,780
Total liabilities and stockholders' equity	1,585,325	1,625,558
Parent Company [Member]
Assets
Cash in subsidiary	11,227	6,393	$ 14,543
Investment in subsidiary	173,253	188,873
Deferred Tax Assets, Net	1,999	2,076
Other assets	3,317	3,307
Total assets	189,796	200,649
Liabilities and Stockholders' Equity
Accrued expenses and other liabilities	2,646	3,015
Total stockholders’ equity	187,150	197,634
Total liabilities and stockholders' equity	$ 189,796	$ 200,649

Company Only Condensed Financ_4

Company Only Condensed Financial Information - Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Interest income	$ 13,103	$ 12,965	$ 12,981	$ 13,021	$ 13,305	$ 12,506	$ 12,193	$ 12,086	$ 52,070	$ 50,090
Other expense	(11,155)	(9,425)	(10,215)	(9,959)	(9,318)	(10,200)	(9,607)	(11,266)	(40,754)	(40,391)
Income (loss) before income taxes	10,219	5,133	5,837	4,859	5,693	4,154	4,144	2,203	26,048	16,194
Income tax expense	$ 2,803	$ 1,396	$ 1,207	$ 1,300	$ 4,702	$ 594	$ 1,572	$ 322	6,706	7,190
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Interest income									0	110
Dividends from subsidiary									36,044	10,629
Other expense									(1,573)	(1,693)
Income (loss) before income taxes									34,471	9,046
Income tax expense									(398)	290
Loss before equity in undistributed subsidiary income									34,869	8,756
Equity in undistributed subsidiary excess distributions									(15,527)	248
Net income (loss)									$ 19,342	$ 9,004

Company Only Condensed Financ_5

Company Only Condensed Financial Information - Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Adjustments:
Change in other assets	$ (94)	$ (3,406)
Net Cash Provided by (Used in) Operating Activities	20,685	22,730
Cash flows from financing activities
Repurchase and retirement of common stock	(23,284)	(10,819)
Cash dividends paid on common stock	(6,449)	(5,153)
Net cash used in financing activities	(58,133)	(6,227)
Parent Company [Member]
Cash flows from operating activities
Net income (loss)	19,342	9,004
Adjustments:
Equity in undistributed subsidiary excess distributions	15,527	(248)
Change in other assets	67	(2,712)
Change in accrued expenses and other liabilities	(369)	3,015
Net Cash Provided by (Used in) Operating Activities	34,567	9,059
Cash flows from financing activities
Net exercise of stock options	0	(1,237)
Repurchase and retirement of common stock	(23,284)	(10,819)
Cash dividends paid on common stock	(6,449)	(5,153)
Net cash used in financing activities	(29,733)	(17,209)
Net change in cash in subsidiary	4,834	(8,150)
Beginning cash in subsidiary	6,393	14,543
Ending cash in subsidiary	$ 11,227	$ 6,393

Selected Quarterly Financial _3

Selected Quarterly Financial Data (unaudited) (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 16,146	$ 15,373	$ 15,020	$ 14,748	$ 15,047	$ 14,121	$ 13,649	$ 13,362	$ 61,287	$ 56,179
Interest expense	3,043	2,408	2,039	1,727	1,742	1,615	1,456	1,276	9,217	6,089
Net interest income	13,103	12,965	12,981	13,021	13,305	12,506	12,193	12,086	52,070	50,090
Provision for (recovery of) loan losses	403	(23)	23	(258)	(72)	(225)	49	161	145	(87)
Net interest income	12,700	12,988	12,958	13,279	13,377	12,731	12,144	11,925	51,925	50,177
Noninterest Income	8,674	1,570	3,094	1,539	1,634	1,623	1,607	1,544	14,877	6,408
Noninterest expense	11,155	9,425	10,215	9,959	9,318	10,200	9,607	11,266	40,754	40,391
Income (loss) before income taxes	10,219	5,133	5,837	4,859	5,693	4,154	4,144	2,203	26,048	16,194
Income tax expense	2,803	1,396	1,207	1,300	4,702	594	1,572	322	6,706	7,190
Net income (loss)	$ 7,416	$ 3,737	$ 4,630	$ 3,559	$ 991	$ 3,560	$ 2,572	$ 1,881	$ 19,342	$ 9,004
Earnings Per Share, Basic	$ 0.44	$ 0.22	$ 0.26	$ 0.20		$ 0.20	$ 0.14	$ 0.10	$ 1.11	$ 0.49
Diluted earnings (loss) per common share (usd per share)		$ 0.22	$ 0.26	$ 0.20	$ 0.06	$ 0.20	$ 0.14	$ 0.10	$ 1.11	$ 0.49

Selected Quarterly Financial _4

Selected Quarterly Financial Data (unaudited) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Net income	$ 7,416	$ 3,737	$ 4,630	$ 3,559	$ 991	$ 3,560	$ 2,572	$ 1,881	$ 19,342	$ 9,004
Earnings Per Share, Basic and Diluted	$ 0.44				$ 0.06
Interest income	$ 13,103	$ 12,965	$ 12,981	$ 13,021	$ 13,305	$ 12,506	$ 12,193	$ 12,086	52,070	50,090
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount					$ 2,500				0	$ 2,487
Equity Securities, FV-NI, Realized Gain	3,600								$ 3,400
Compensation expense	$ 1,000