Waterstone Financial (WSBF) 10-K 6 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 28, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	Waterstone Financial, Inc.
Entity Central Index Key	1,569,994
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 557.1
Entity Common Stock, Shares Outstanding		29,385,316
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash	$ 22,306	$ 7,878
Federal funds sold	17,034	26,828
Interest-earning deposits in other financial institutions and other short term investments	9,267	12,511
Cash and cash equivalents	48,607	47,217
Securities available for sale (at fair value)	199,707	226,795
Loans held for sale (at fair value)	149,896	225,248
Loans receivable	1,291,814	1,177,884
Less: Allowance for loan losses	14,077	16,029
Loans receivable, net	1,277,737	1,161,855
Office properties and equipment, net	22,941	23,655
Federal Home Loan Bank stock (at cost)	16,875	13,275
Cash surrender value of life insurance	65,996	61,509
Real estate owned, net	4,558	6,118
Prepaid expenses and other assets	20,084	24,947
Total assets	1,806,401	1,790,619
Liabilities:
Demand deposits	129,597	120,371
Money market and savings deposits	148,804	162,456
Time deposits	688,979	666,584
Total deposits	967,380	949,411
Long-term borrowings	386,285	387,155
Advance payments by borrowers for taxes	4,876	4,716
Other liabilities	35,756	38,647
Total liabilities	1,394,297	1,379,929
Shareholders' equity:
Preferred stock (par value $.01 per share) Authorized - 50,000,000 shares in 2017 and in 2016, no shares issued	0	0
Common stock (par value $.01 per share) Authorized - 100,000,000 shares in 2017 and in 2016, Issued - 29,554,466 in 2017 and 29,430,123 in 2016, Outstanding - 29,554,466 in 2017 and 29,430,123 in 2016	295	294
Additional paid-in capital	326,655	322,934
Retained earnings	183,358	184,565
Unearned ESOP shares	(18,991)	(20,178)
Accumulated other comprehensive income (loss), net of taxes	(477)	(378)
Cost of shares repurchased (5,957,833 shares at September 30, 2017 and 5,908,150 shares at December 31, 2016)	(78,736)	(76,547)
Total shareholders' equity	412,104	410,690
Total liabilities and shareholders' equity	$ 1,806,401	$ 1,790,619

Consolidated Statements of Fin3

Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Securities held to maturity	$ 0	$ 0
Shareholders' equity:
Preferred stock - par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock - shares authorized (in shares)	50,000,000	50,000,000
Preferred stock - shares issued (in shares)	0	0
Common stock - par value (in dollars per share)	$ 0.01	$ 0.01
Common stock - shares authorized (in shares)	100,000,000	100,000,000
Common stock - shares issued (in shares)	29,501,346	29,430,123
Common stock - shares outstanding (in shares)	29,501,346	29,430,123
Treasury shares (in shares)	6,030,900	5,908,150

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Loans	$ 60,824	$ 57,185	$ 55,175
Mortgage-related securities	2,646	3,048	3,229
Debt securities, federal funds sold and short-term investments	3,625	3,503	3,559
Total interest income	67,095	63,736	61,963
Interest expense:
Deposits	7,739	7,364	5,879
Borrowings	8,623	12,928	17,240
Total interest expense	16,362	20,292	23,119
Net interest income	50,733	43,444	38,844
Provision for loan losses	(1,166)	380	1,965
Net interest income after provision for loan losses	51,899	43,064	36,879
Noninterest income:
Service charges on loans and deposits	1,625	2,232	1,648
Increase in cash surrender value of life insurance	1,807	1,767	1,417
Mortgage banking income	120,044	121,069	99,318
Gain on sale of available for sale securities	(107)	0	44
Other	1,044	1,297	2,047
Total noninterest income	124,413	126,365	104,474
Noninterest expenses:
Compensation, payroll taxes, and other employee benefits	97,084	95,056	81,753
Occupancy, office furniture and equipment	10,178	9,347	9,287
Advertising	3,333	2,743	2,947
Data processing	2,439	2,520	2,354
Communications	1,560	1,462	1,416
Professional fees	2,656	2,135	2,354
Real estate owned	379	399	2,664
FDIC insurance premiums	499	615	1,058
Other	13,751	13,158	11,701
Total noninterest expenses	131,879	127,435	115,534
Income (loss) before income tax	44,433	41,994	25,819
Income tax expense (benefit)	18,469	16,462	9,249
Net income (loss)	$ 25,964	$ 25,532	$ 16,570
Income per share:
Basic (in dollars per share)	$ 0.95	$ 0.94	$ 0.57
Diluted (in dollars per share)	$ 0.93	$ 0.93	$ 0.56
Weighted average shares outstanding:
Basic (in shares)	27,467	27,037	29,161
Diluted (in shares)	27,899	27,374	29,431

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Net income (loss)	$ 25,964	$ 25,532	$ 16,570
Other comprehensive income (loss), net of tax
Net unrealized holding gain arising during the period, net of tax expense of ($204), ($528), ($356), ($1,728), respectively	(159)	(960)	(638)
Recognition of net deferred tax liability revaluation due to tax law change	(5)	0	0
Reclassification adjustment for net loss included in net income during the period, net of tax benefit of ($42), $0, ($42), $0, respectively	65	0	(27)
Total other comprehensive income (loss)	(99)	(960)	(665)
Comprehensive income	$ 25,865	$ 24,572	$ 15,905

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other comprehensive income (loss), net of tax
Net unrealized holding gain (loss) on available for sale securities arising during the period, net of tax (expense) benefit	$ 106	$ 622	$ 412
Reclassification adjustment for net gains on available for sale securities realized during the period, net of taxes	$ (42)	$ 0	$ 17

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Merger of Lamplighter MHC (Common Stock)- Member [Member]	Cash dividend - Common Stock [Member]	Stock Based Compensation Expense - Common Stock [Member]	Stock Compensation Activity [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Unearned ESOP Shares [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Cost of Shares Repurchased [Member]	Total
Balances at Dec. 31, 2014	$ 344					$ 313,894	$ 157,304	$ (22,552)	$ 1,247	$ 0	$ 450,237
Balances (in shares) at Dec. 31, 2014	34,420
Comprehensive income:
Net income (loss)	$ 0					0	16,570	0	0	0	16,570
Other comprehensive income	0					0	0	0	(665)	0	(665)
Total comprehensive income											15,905
ESOP shares committed to be released to Plan participants	0					198	0	1,187	0	0	1,385
Cash dividend	0					0	(5,785)	0	0	0	(5,785)
Stock compensation activity, net of tax	6					113	0	0	0	0	119
Stock based compensation expense	0					2,817	0	0	0	0	2,817
Merger of Lamplighter MHC	$ (56)					0	0	0	0	(72,692)	(72,748)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)	0	(5,624)	0	0	611
Balances at Dec. 31, 2015	$ 294					317,022	168,089	(21,365)	582	(72,692)	391,930
Balances (in shares) at Dec. 31, 2015	29,407
Comprehensive income:
Net income (loss)	$ 0					0	25,532	0	0	0	25,532
Other comprehensive income	0					0	0	0	(960)	0	(960)
Total comprehensive income											24,572
ESOP shares committed to be released to Plan participants	0					446	0	1,187	0	0	1,633
Cash dividend	0					0	(9,056)	0	0	0	(9,056)
Stock compensation activity, net of tax	3					3,553	0	0	0	0	3,556
Stock based compensation expense	0					1,913	0	0	0	0	1,913
Merger of Lamplighter MHC	(3)					0	0	0	0	(3,855)	(3,858)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)		(284)	0	0	307
Balances at Dec. 31, 2016	$ 294					322,934	184,565	(20,178)	(378)	(76,547)	$ 410,690
Balances (in shares) at Dec. 31, 2016	29,430										29,430,123
Comprehensive income:
Net income (loss)	$ 0					0	25,964	0	0	0	$ 25,964
Other comprehensive income	0					0	0	0	(99)	0	(99)
Total comprehensive income											25,865
ESOP shares committed to be released to Plan participants	0					769	0	1,187	0	0	1,956
Cash dividend	0					0	(27,171)	0	0	0	(27,171)
Stock compensation activity, net of tax	2					1,050	0	0	0	0	1,052
Stock based compensation expense	0					1,902	0	0	0	0	1,902
Merger of Lamplighter MHC	(1)					0	0	0	0	(2,189)	(2,190)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)		(123)	0	0	194
Balances at Dec. 31, 2017	$ 295					$ 326,655	$ 183,358	$ (18,991)	$ (477)	$ (78,736)	$ 412,104
Balances (in shares) at Dec. 31, 2017	29,501										29,501,346

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities:
Net income (loss)	$ 25,964	$ 25,532	$ 16,570
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for loan losses	(1,166)	380	1,965
Provision for depreciation	2,050	2,615	3,106
Deferred income taxes	3,079	1,564	(154)
Stock based compensation	1,902	1,913	2,817
Net amortization of premium/discount on debt and mortgage related securities	682	991	1,305
Amortization of unearned ESOP shares	1,956	1,633	1,385
Amortization Of MSR	106	598	491
Gain on sale of loans held for sale	(121,951)	(123,154)	(98,382)
Loans originated for sale	(2,458,370)	(2,378,926)	(1,986,147)
Proceeds on sales of loans originated for sale	2,655,673	2,443,347	2,043,086
Increase in accrued interest receivable	(643)	(173)	(79)
Increase in cash surrender value of life insurance	(1,807)	(1,767)	(1,417)
Increase (decrease) in accrued interest on deposits and borrowings	(30)	(726)	42
(Decrease) increase in other liabilities	(3,079)	4,659	2,425
Increase in accrued tax receivable	(1,686)	557	1,467
Gain on sale of available for sale securities	107	0	(44)
Net loss related to real estate owned	(24)	(197)	968
Gain Loss On Sale Of Mortgage Servicing Rights	(178)	0	(901)
Other	4,512	(2,908)	(1,494)
Net cash (used in) provided by operating activities	107,097	(24,062)	(12,991)
Investing activities:
Net decrease in loans receivable	(116,887)	(68,076)	(40,011)
Purchases of:
Debt securities	(6,140)	(5,285)	(16,119)
Mortgage related securities	(16,827)	(9,215)	(33,750)
Net change on FHLB stock	(3,600)	6,225	(2,000)
Premises and equipment, net	(1,577)	(1,085)	(2,966)
Bank owned life insurance	(2,680)	(10,180)	(180)
Proceeds from:
Principal repayments on mortgage-related securities	32,968	39,935	40,755
Maturities of debt securities	15,686	14,855	9,510
Sales of debt securities	448	0	1,034
Death Benefit from BOLI	0	0	2,883
Sales of foreclosed properties and other assets	3,733	7,796	24,716
Net cash used in investing activities	(94,876)	(25,030)	(16,128)
Financing activities:
Net (decrease) increase in deposits	17,969	56,050	29,401
Net increase (decrease) in short-term borrowings	(26,870)	65,952	7,203
Repayment of Long Term Debt	(149,000)	(220,000)	0
Financing activities: Proceeds from Long Term Debt	175,000	100,000	0
Net increase (decrease) in advance payments by borrowers for taxes	160	1,055	(1,330)
Financing for cash dividends on common stock	(26,952)	(6,917)	(5,869)
Proceeds from stock option exercises	1,052	3,556	113
Purchase of common stock returned to authorized but unissued	(2,190)	(3,858)	(72,748)
Net cash provided by financing activities	(10,831)	(4,162)	(43,230)
Increase (decrease) in cash and cash equivalents	1,390	(53,254)	(72,349)
Cash and cash equivalents at beginning of period	47,217	100,471	172,820
Cash and cash equivalents at end of period	48,607	47,217	100,471
Cash paid or credited during the period for:
Income tax payments (refunds)	17,081	14,352	7,933
Interest payments	16,392	21,018	23,077
Noncash activities:
Loans receivable transferred to other real estate	2,171	4,590	15,580
Dividends declared but not paid in other liabilities	$ 3,894	$ 3,677	$ 1,537

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1) Summary of Significant Accounting Policies The following significant accounting and reporting policies of Waterstone Financial, Inc. and subsidiaries (collectively, the "Company"), conform to U.S. generally accepted accounting principles, or ("GAAP"), and are used in preparing and presenting these consolidated financial statements. a) Nature of Operations The Company is a one-bank holding company with two operating segments – community banking and mortgage banking. WaterStone Bank SSB (the "Bank" or "WaterStone Bank") is principally engaged in the business of attracting deposits from the general public and using such deposits to originate real estate, business and consumer loans. The Bank provides a full range of financial services to customers through branch locations in southeastern Wisconsin. In addition, the Bank has a loan production office in Minneapolis, Minnesota. The Bank is subject to the regulations of certain federal and state agencies and undergoes periodic examinations by those regulatory authorities. The Bank owns a mortgage banking subsidiary that originates residential real estate loans held for sale at various branch offices across the country. Mortgage banking volume fluctuates widely given movements in interest rates. Mortgage banking income is reported as a single line item in the statements of operations while mortgage banking expense is distributed among the various noninterest expense lines. Compensation, payroll taxes and other employee benefits expense varies directly with mortgage banking income. b) Principles of Consolidation The consolidated financial statements include the accounts and operations of Waterstone Financial, Inc. and its wholly owned subsidiary, WaterStone Bank. The Bank has the following wholly owned subsidiaries: Wauwatosa Investments, Inc., Waterstone Mortgage Corporation, and Main Street Real Estate Holdings, LLC. All significant intercompany accounts and transactions have been eliminated in consolidation. c) Use of Estimates The preparation of the consolidated financial statements requires management of the Company to make a number of estimates and assumptions relating to the reported amount of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the period. Significant items subject to such estimates and assumptions include: the allowance for loan losses, income taxes, and fair value measurements. Actual results could differ from those estimates and the current economic environment has increased the degree of uncertainty inherent in those estimates and assumptions. e) Cash and Cash Equivalents The Company considers federal funds sold and highly liquid debt instruments with a maturity of three months or less when purchased to be cash equivalents. e) Securities Available for Sale Securities At the time of purchase, investment securities are classified as available for sale, as management has the intent and ability to hold such securities for an indefinite period of time, but not necessarily to maturity. Any decision to sell investment securities available for sale would be based on various factors, including, but not limited to asset/liability management strategies, changes in interest rates or prepayment risks, liquidity needs, or regulatory capital considerations. Available for sale securities are carried at fair value, with the unrealized gains and losses, net of deferred tax, reported as a separate component of equity in accumulated other comprehensive income. The cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity or, in the case of mortgage-backed securities and collateralized mortgage obligations, over the estimated life of the security. Such amortization is included in interest income from securities. Realized gains or losses on securities sales (using specific identification method) are included in other income. Declines in value judged to be other than temporary are included in net impairment losses recognized in earnings in the consolidated statements of operations. Other Than Temporary Impairment One of the significant estimates related to securities is the evaluation of investments for other than temporary impairment. The Company assesses investment securities with unrealized loss positions for other than temporary impairment on at least a quarterly basis. When the fair value of an investment is less than its amortized cost at the balance sheet date of the reporting period for which impairment is assessed, the impairment is designated as either temporary or other than temporary. In evaluating other than temporary impairment, management considers the length of time and extent to which the fair value has been less than cost and the expected recovery period of the security, the financial condition and near-term prospects of the issuer, and the intent and ability of the Company to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value in the near term. Declines in the fair value of investment securities below amortized cost are deemed to be other than temporary when the Company cannot assert that it will recover its amortized cost basis, including whether the present value of cash flows expected to be collected is less than the amortized cost basis of the security. If it is more likely than not that the Company will be required to sell the security before recovery or if the Company has the intent to sell, an other than temporary impairment write down is recognized in earnings equal to the difference between the security's amortized cost and its fair value. If it is not more likely than not that the Company will be required to sell the security before recovery and if the Company does not intend to sell, the other than temporary impairment write down is separated into an amount representing credit loss, which is recognized in earnings, and an amount related to other factors, which is recognized as a separate component of equity. Following the recognition of an other than temporary impairment representing credit loss, the book value of an investment less the impairment loss realized becomes the new cost basis. The determination as to whether an other than temporary impairment exists and, if so, the amount considered other than temporarily impaired, or not impaired, is subjective and, therefore, the timing and amount of other than temporary impairments constitute material estimates that are subject to significant change. Federal Home Loan Bank Stock Federal Home Loan Bank ("FHLB") stock is carried at cost, which is the amount that the stock is redeemable by tendering to the FHLB or the amount at which shares can be sold to other FHLB members. f) Loans Held for Sale The origination of residential real estate loans is an integral component of the business of the Company. The Company generally sells its originations of long-term fixed interest rate mortgage loans in the secondary market, and on a selective basis, retains the rights to service the loans sold. Gains and losses on the sales of these loans are determined using the specific identification method. Mortgage loans originated for sale are generally sold within 45 days after closing. The Company has elected to carry loans held for sale at fair value. Fair value is generally determined by estimating a gross premium or discount, which is derived from pricing currently observable in the market. The amount by which cost differs from market value is accounted for as a valuation adjustment to the carrying value of the loans. Changes in value are included in mortgage banking income in the consolidated statements of operations. Costs to originate loans held for sale are expensed as incurred and are included on the appropriate noninterest expense lines of the statements of operations. Salaries, commissions and related payroll taxes are the primary costs to originate and comprised approximately 75.5% of total mortgage banking noninterest expense for 2017. The value of mortgage loans held for sale and other residential mortgage loan commitments to customers are hedged by utilizing both best efforts and mandatory forward commitments to sell loans to investors in the secondary market. Such forward commitments are generally entered into at the time when applications are taken to protect the value of the mortgage loans from increases in market interest rates during the period held. The Company recognizes revenue associated with the expected future cash flows of servicing loans at the time a forward loan commitment is made, as required under Securities and Exchange Commission Staff Accounting Bulletin No. 109, Written Loan Commitments Recorded at Fair Value Through Earnings. g) Loans Receivable and Related Interest Income Loans are classified as held for investment when management has both the intent and ability to hold the loan for the foreseeable future, or until maturity or payoff. Loans are carried at the principal amount outstanding, net of any unearned income, charge-offs and unamortized deferred fees and costs. Loan origination and commitment fees and certain direct loan origination costs are deferred and the net amount amortized as an adjustment of the related loan yield. Amortization is based on a level-yield method over the contractual life of the related loans or until the loan is paid in full. Loan interest income is recognized on the accrual basis. Accrual of interest is generally discontinued either when reasonable doubt exists as to the full, timely collection of interest or principal, or when a loan becomes contractually past due more than 90 days with respect to interest or principal. At that time, previously accrued and uncollected interest on such loans is reversed and additional income is recorded only to the extent that payments are received and the collection of principal is reasonably assured. Generally, loans are restored to accrual status when the obligation is brought current, has performed in accordance with the contractual terms for a reasonable period of time, and the ultimate collectability of the total contractual principal and interest is no longer in doubt. A loan is accounted for as a troubled debt restructuring if the Company, for economic reasons related to the borrower's financial condition, grants a concession to the borrower that it would not otherwise consider. A troubled debt restructuring typically involves a modification of terms such as a reduction of the stated interest rate, a deferral of principal payments or a combination of both for a temporary period of time. If the borrower was performing in accordance with the original contractual terms at the time of the restructuring, the restructured loan is accounted for on an accruing basis as long as the borrower continues to comply with the modified terms. If the loan was not accounted for on an accrual basis at the time of restructuring, the restructured loan remains in non-accrual status until the loan completes a minimum of six consecutive contractual payments. h) Allowance for Loan Losses The allowance for loan losses is presented as a reserve against loans and represents the Bank's assessment of probable loan losses inherent in the loan portfolio. The allowance for loan losses is established as losses are estimated to have occurred through a provision for loan losses charged to income. Estimated loan losses are charged against the allowance when the loan balance is confirmed to be uncollectible directly or indirectly by the borrower or upon initiation of a foreclosure action by the Bank. Subsequent recoveries, if any, are credited to the allowance as long as it is within 90 days of being transferred to real estate owned. The allowance provides for probable losses that have been identified with specific customer relationships and for probable losses believed to be inherent in the loan portfolio, but have not been specifically identified. The Bank utilizes its own loss history to estimate inherent losses on loans. Although the Bank allocates portions of the allowance to specific loans and loan types, the entire allowance is available for any loan losses that occur. The Bank evaluates the need for specific valuation allowances on loans that are considered impaired. A loan is considered impaired when, based on current information and events, it is probable that the Bank will not be able to collect all amounts due according to the contractual terms of the loan agreement. Within the loan portfolio, all non-accrual loans and loans modified under troubled debt restructurings have been determined by the Bank to meet the definition of an impaired loan. In addition, other loans may be considered impaired loans. A valuation allowance is established for an amount equal to the impairment when the carrying amount of the loan exceeds the present value of the expected future cash flows, discounted at the loan's original effective interest rate or the fair value of the underlying collateral. The Bank also establishes valuation allowances based on an evaluation of the various risk components that are inherent in the loan portfolio. The risk components that are evaluated include past loan loss experience; the level of non-performing and classified assets; current economic conditions; volume, growth, and composition of the loan portfolio; adverse situations that may affect the borrower's ability to repay; the estimated value of any underlying collateral; regulatory guidance; and other relevant factors. The appropriateness of the allowance for loan losses is approved quarterly by the Bank's board of directors. The allowance reflects management's best estimate of the amount needed to provide for the probable loss on impaired loans, as well as other credit risks of the Bank, and is based on a risk model developed and implemented by management and approved by the Bank's board of directors. Actual results could differ from this estimate, and future additions to the allowance may be necessary based on unforeseen changes in economic conditions. In addition, federal regulators periodically review the Bank's allowance for loan losses. Such regulators have the authority to require the Bank to recognize additions to the allowance at the time of their examination. i) Real Estate Owned Real estate owned consists of properties acquired through, or in lieu of, loan foreclosure. Real estate owned is transferred into the portfolio at estimated net realizable value. To the extent that the net carrying value of the loan exceeds the estimated fair value of the property at the date of transfer, the excess is charged to the allowance for loan losses within 90 days of being transferred. Subsequent write-downs to reflect current fair market value, as well as gains and losses upon disposition and revenue and expenses incurred in maintaining such properties, are treated as period costs and included in real estate owned in the consolidated statements of operations. j) Mortgage Servicing Rights The Company sells residential mortgage loans in the secondary market and, on a selective basis, retains the right to service the loans sold. Upon sale, a mortgage servicing rights asset is capitalized, which represents the then current fair value of future net cash flows expected to be realized for performing servicing activities. Mortgage servicing rights, when purchased, are initially recorded at fair value. Mortgage servicing rights are amortized over the period of estimated net servicing income, and assessed for impairment at each reporting date. Mortgage servicing rights are carried at the lower of the initial capitalized amount, net of accumulated amortization, or estimated fair value, and are included in other assets, net in the consolidated balance sheets. To the extent that the Company sells mortgage servicing rights, a gain is recognized for the amount of which sale proceeds exceed the remaining unamortized cost of the servicing rights that were sold. Gains on sale of mortgage servicing rights are included in other noninterest income in the consolidated statements of operations. k) Cash Surrender Value of Life Insurance The Company purchased bank owned life insurance on the lives of certain employees. The Company is the beneficiary of the life insurance policies. The cash surrender value of life insurance is reported at the amount that would be received in cash if the polices were surrendered. Increases in the cash value of the policies and proceeds of death benefits received are recorded in noninterest income. The increase in cash surrender value of life insurance is not subject to income taxes, as long as the Company has the intent and ability to hold the policies until the death benefits are received. l) Office Properties and Equipment Office properties and equipment, including leasehold improvements and software, are stated at cost, net of depreciation and amortization. Depreciation and amortization are computed on the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the lease term, if shorter than the estimated useful life. Maintenance and repairs are charged to expense as incurred, while additions or major improvements are capitalized and depreciated over their estimated useful lives. Estimated useful lives of the assets are 10 to 30 years for office properties, three to 10 years for equipment, and three years for software. Rent expense related to long-term operating leases is recorded on the accrual basis. m) Income Taxes The Company and its subsidiaries file consolidated federal and combined state income tax returns. The provision for income taxes is based upon income in the consolidated financial statements, rather than amounts reported on the income tax returns. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as net operating loss carry forwards. 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 as income or expense in the period that includes the enactment date. The Company evaluates the realizability of its deferred tax assets on a quarterly basis. Under generally accepted accounting principles, a valuation allowance is required to be recognized if it is "more likely than not" that a 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 income, applicable tax planning strategies, and assessments of current and future economic and business conditions. Positions taken in the Company's tax returns may be subject to challenge by the taxing authorities upon examination. The benefit of uncertain tax positions are initially recognized in the financial statements only when it is more likely than not the position will be sustained upon examination by the tax authorities. Such tax positions are both initially and subsequently measured as the largest amount of tax benefit that is greater than 50% likely of being realized upon settlement with the tax authority, assuming full knowledge of the position and all relevant facts. Interest and penalties on income tax uncertainties are classified within income tax expense in the income statement. n) Earnings Per Share Earnings per share are computed using the two-class method. Basic earnings per share is computed by dividing net income allocated to common shareholders by the weighted average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Diluted earnings per share is computed by dividing net income by the weighted average number of common shares outstanding adjusted for the dilutive effect of all potential common shares. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised. Shares of the Employee Stock Ownership Plan committed to be released are considered outstanding for both common and diluted EPS. Incentive stock compensation awards granted can result in dilution. o) Comprehensive Income Comprehensive income is the total of reported net income and changes in unrealized gains or losses, net of tax, on securities available for sale. p) Employee Stock Ownership Plan (ESOP) Compensation expense under the ESOP is equal to the fair value of common shares released or committed to be released to participants in the ESOP in each respective period. Common stock purchased by the ESOP and not committed to be released to participants is included in the consolidated statements of financial condition at cost as a reduction of shareholders' equity. q) Impact of Recent Accounting Pronouncements Accounting Standards Codification (ASC) Topic 606 "Revenue from Contracts with Customers." ASC Topic 825 "Financial Instruments." ASC Topic 842 "Leases." ASC Topic 718 "Compensation - Stock Compensation." ASC Topic 326 "Financial Instruments - Credit Losses." ASC Topic 310 "Receivables - Nonrefundable Fees and Other Costs." ASC Topic 220 "Income Statement - Reporting Comprehensive Income."

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Securities Available for Sale [Abstract]
Securities Available for Sale	2) Securities Securities Available for Sale The amortized cost and fair value of the Company's investment in securities follow: December 31, 2017 Amortized cost Gross unrealized gains Gross unrealized losses Fair value (In Thousands) Mortgage-backed securities $ 57,351 324 (240 ) 57,435 Collateralized mortgage obligations Government sponsored enterprise issued 61,313 3 (816 ) 60,500 Mortgage related securities 118,664 327 (1,056 ) 117,935 Government sponsored enterprise bonds 2,500 – (3 ) 2,497 Municipal securities 62,516 1,334 (81 ) 63,769 Other debt securities 15,005 12 (492 ) 14,525 Debt securities 80,021 1,346 (576 ) 80,791 Certificates of deposit 980 1 - 981 $ 199,665 1,674 (1,632 ) 199,707 December 31, 2016 Amortized cost Gross unrealized gains Gross unrealized losses Fair value (In Thousands) Mortgage-backed securities $ 72,858 798 (243 ) 73,413 Collateralized mortgage obligations Government sponsored enterprise issued 62,297 70 (365 ) 62,002 Mortgage related securities 135,155 868 (608 ) 135,415 Government sponsored enterprise bonds 2,500 4 (1 ) 2,503 Municipal securities 70,311 685 (300 ) 70,696 Other debt securities 17,399 154 (603 ) 16,950 Debt securities 90,210 843 (904 ) 90,149 Certificates of deposit 1,225 7 (1 ) 1,231 $ 226,590 1,718 (1,513 ) 226,795 The Company's mortgage-backed securities and collateralized mortgage obligations issued by government sponsored enterprises are guaranteed by one of the following government sponsored enterprises: Fannie Mae, Freddie Mac or Ginnie Mae. At December 31, 2017, $2.5 million of the Company's mortgage related securities were pledged as collateral to secure The amortized cost and fair value of securities at December 31, 2017, by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because issuers or borrowers may have the right to prepay obligations with or without prepayment penalties. December 31, 2017 Amortized cost Fair value (In Thousands) Debt securities: Due within one year $ 10,204 10,180 Due after one year through five years 22,312 22,330 Due after five years through ten years 36,309 37,461 Due after ten years 12,176 11,801 Mortgage-related securities 118,664 117,935 $ 199,665 199,707 Total proceeds and gross gains and losses from sales of investment securities available for sale for each of periods listed below. December 31, 2017 2016 2015 (In Thousands) Gross gains $ - - 44 Gross losses (107 ) - - Gains on sale of investment securities, net $ (107 ) - 44 Proceeds from sales of investment securities $ 448 - 1,034 Gross unrealized losses on securities available for sale and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows: December 31, 2017 Less than 12 months 12 months or longer Total Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss (In Thousands) Mortgage-backed securities $ 35,136 (143 ) 4,464 (97 ) 39,600 (240 ) Collateralized mortgage obligations Government sponsored enterprise issued 37,949 (348 ) 21,651 (468 ) 59,600 (816 ) Government sponsored enterprise bonds 2,497 (3 ) - - 2,497 (3 ) Municipal securities 17,096 (80 ) 100 (1 ) 17,196 (81 ) Other debt securities - - 9,508 (492 ) 9,508 (492 ) Certificates of deposit - - - - – - $ 92,678 (574 ) 35,723 (1,058 ) 128,401 (1,632 ) December 31, 2016 Less than 12 months 12 months or longer Total Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss (In Thousands) Mortgage-backed securities $ 23,433 (222 ) 1,068 (21 ) 24,501 (243 ) Collateralized mortgage obligations Government sponsored enterprise issued 39,395 (365 ) - - 39,395 (365 ) Government sponsored enterprise bonds 2,000 (1 ) - - 2,000 (1 ) Municipal securities 32,141 (300 ) - - 32,141 (300 ) Other debt securities - - 9,397 (603 ) 9,397 (603 ) Certificates of deposit 489 (1 ) - - 489 (1 ) $ 97,458 (889 ) 10,465 (624 ) 107,923 (1,513 ) The Company reviews the investment securities portfolio on a quarterly basis to monitor its exposure to other-than-temporary impairment. In evaluating whether a security's decline in market value is other-than-temporary, management considers the length of time and extent to which the fair value has been less than cost, financial condition of the issuer and the underlying obligors, quality of credit enhancements, volatility of the fair value of the security, the expected recovery period of the security and ratings agency evaluations. In addition, the Company may also evaluate payment structure, whether there are defaulted payments or expected defaults, prepayment speeds and the value of any underlying collateral. As of December 31, 2017, the Company identified one municipal security that was deemed to be other-than-temporarily impaired. The security was issued by a tax incremental district in a municipality located in Wisconsin. During the year ended December 31, 2012, the Company received audited financial statements with respect to the municipal issuer that called into question the ability of the underlying taxing district that issued the securities to operate as a going concern. During the year ended December 31, 2012, the Company's analysis of the security in this municipality resulted in $77,000 in credit losses that were charged to earnings with respect to this municipal security. An additional $17,000 credit loss was charged to earnings during the year ended December 31, 2014 with respect to this security as a sale occurred at a discounted price. As of December 31, 2017, the remaining impaired security had an amortized cost of $116,000 and a total life-to-date impairment of $94,000. As of December 31, 2017, the Company had one corporate debt security, one municipal security, five mortgage-backed security, and 14 government sponsored enterprise issued securities which had been in an unrealized loss position for twelve months or longer. These securities were determined not to be other-than-temporarily impaired as of December 31, 2017. The Company has determined that the decline in fair value of these securities is not attributable to credit deterioration, and as the Company does not intend to sell nor is it more likely than not that it will be required to sell these securities before recovery of the amortized cost basis, these securities are not considered other-than-temporarily impaired. Deterioration of general economic market conditions could result in the recognition of future other-than-temporary impairment losses within the investment portfolio and such amounts could be material to our consolidated financial statements. During the year ended December 31, 2017, proceeds from the sale of securities totaled $448,000 and resulted in losses totaling $107,000. The $107,000 included in loss on sale of available for sale securities in the consolidated statements of income during the year ended December 31, 2017 was reclassified from accumulated other comprehensive income. There were no sales of securities during the year ended December 31, 2016. The following table presents the change in other-than-temporary credit related impairment charges on municipal securities for which a portion of the other-than-temporary impairments related to other factors was recognized in other comprehensive loss. (In Thousands) Credit-related impairments on securities as of December 31, 2015 $ 117 Credit related impairments related to a security for which other-than-temporary impairment was not previously recognized $ - Decrease in credit related impairments related to securities for which an other-than-temporary impairment was previously recognized (23 ) Credit-related impairments on securities as of December 31, 2016 $ 94 Credit related impairments related to a security for which other-than-temporary impairment was not previously recognized $ - Increase in credit related impairments related to securities for which an other-than-temporary impairment was previously recognized - Credit-related impairments on securities as of December 31, 2017 $ 94

Loans Receivable

Loans Receivable	12 Months Ended
	Dec. 31, 2017
Loan Receivable [Abstract]
Loans Receivable	3) Loans Receivable Loans receivable at December 31, 2017 and 2016 are summarized as follows: December 31, 2017 2016 Mortgage loans: (In Thousands) Residential real estate: One- to four-family $ 439,597 392,817 Multi family 578,440 558,592 Home equity 21,124 21,778 Construction and land 19,859 18,179 Commercial real estate 195,842 159,401 Consumer 255 319 Commercial loans 36,697 26,798 Total loans receivable $ 1,291,814 1,177,884 The Company provides several types of loans to its customers, including residential, construction, commercial and consumer loans. Significant loan concentrations are considered to exist for a financial institution when there are amounts loaned to one borrower or to multiple borrowers engaged in similar activities that would cause them to be similarly impacted by economic or other conditions. While credit risks tend to be geographically concentrated in the Company's Milwaukee metropolitan area and while 80.4% of the Company's loan portfolio involves loans that are secured by residential real estate, there are no concentrations with individual or groups of related borrowers. While the real estate collateralizing these loans is primarily residential in nature, it ranges from owner-occupied single family homes to large apartment complexes. Qualifying loans receivable totaling $971.3 million and $911.9 million are pledged as collateral against $375.0 million in outstanding Federal Home Loan Bank of Chicago advances under a blanket security agreement at both December 31, 2017 and December 31, 2016. Certain of the Company's executive officers, directors, employees, and their related interests have loans with the Bank. As of December 31, 2017 and December 31, 2016, loans aggregating approximately $4.5 million and $5.1 million, respectively, were outstanding to such parties. None of these loans were considered impaired as of December 31, 2017 or December 31, 2016. An analysis of past due loans receivable as of December 31, 2017 and 2016 follows: As of December 31, 2017 1-59 Days Past Due (1) 60-89 Days Past Due (2) Greater Than 90 Days Total Past Due Current (3) Total Loans Mortgage loans: (In Thousands) Residential real estate: One- to four-family $ 1,494 146 3,516 5,156 434,441 439,597 Multi family - 128 192 320 578,120 578,440 Home equity 68 - 56 124 21,000 21,124 Construction and land - - - - 19,859 19,859 Commercial real estate - - 184 184 195,658 195,842 Consumer - - - - 255 255 Commercial loans - 42 26 68 36,629 36,697 Total $ 1,562 316 3,974 5,852 1,285,962 1,291,814 As of December 31, 2016 1-59 Days Past Due (1) 60-89 Days Past Due (2) Greater Than 90 Days Total Past Due Current (3) Total Loans Mortgage loans: (In Thousands) Residential real estate: One- to four-family $ 2,403 7 4,623 7,033 385,784 392,817 Multi family 376 - 401 777 557,815 558,592 Home equity 82 - 35 117 21,661 21,778 Construction and land - - - - 18,179 18,179 Commercial real estate - - 203 203 159,198 159,401 Consumer - - - - 319 319 Commercial loans 42 - 27 69 26,729 26,798 Total $ 2,903 7 5,289 8,199 1,169,685 1,177,884 (1) Includes $241,000 and $148,000 for December 31, 2017 and 2016, respectively, which are on non-accrual status. (2) Includes $15,000 and $- for December 31, 2017 and 2016, respectively, which are on non-accrual status. (3) Includes $1.8 million and $4.4 million for December 31, 2017 and 2016, respectively, which are on non-accrual status. As of December 31, 2017 and 2016, there were no loans that were 90 or more days past due and still accruing interest. A summary of the activity for the years ended 2017, 2016 and 2015 in the allowance for loan losses follows: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total (In Thousands) Year ended December 31, 2017 Balance at beginning of period $ 7,164 4,809 364 1,016 1,951 12 713 16,029 Provision for loan losses (299 ) (494 ) (34 ) (215 ) (64 ) (3 ) (57 ) (1,166 ) Charge-offs (1,364 ) (92 ) - (14 ) (7 ) - - (1,477 ) Recoveries 293 208 26 162 1 1 - 691 Balance at end of period $ 5,794 4,431 356 949 1,881 10 656 14,077 Year ended December 31, 2016 Balance at beginning of period $ 7,763 5,000 433 904 1,680 9 396 16,185 Provision for loan losses (407 ) 146 7 43 271 3 317 380 Charge-offs (1,003 ) (489 ) (112 ) (3 ) - - - (1,607 ) Recoveries 811 152 36 72 - - - 1,071 Balance at end of period $ 7,164 4,809 364 1,016 1,951 12 713 16,029 Year ended December 31, 2015 Balance at beginning of period $ 9,877 5,358 422 687 1,951 8 403 18,706 Provision for loan losses 1,092 931 (27 ) 243 (266 ) (1 ) (7 ) 1,965 Charge-offs (3,855 ) (2,281 ) (72 ) (84 ) (45 ) (3 ) - (6,340 ) Recoveries 649 992 110 58 40 5 - 1,854 Balance at end of period $ 7,763 5,000 433 904 1,680 9 396 16,185 A summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class as of the year ended December 31, 2017 follows: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total (In Thousands) Allowance related to loans individually evaluated for impairment $ 77 - 44 - 34 - - 155 Allowance related to loans collectively evaluated for impairment 5,717 4,431 312 949 1,847 10 656 13,922 Balance at end of period $ 5,794 4,431 356 949 1,881 10 656 14,077 Loans individually evaluated for impairment $ 7,418 1,007 185 - 540 - 26 9,176 Loans collectively evaluated for impairment 432,179 577,433 20,939 19,859 195,302 255 36,671 1,282,638 Total gross loans $ 439,597 578,440 21,124 19,859 195,842 255 36,697 1,291,814 A summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class as of the year ended December 31, 2016 follows: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total (In Thousands ) Allowance related to loans individually evaluated for impairment $ 499 - 79 - 83 - 1 662 Allowance related to loans collectively evaluated for impairment 6,665 4,809 285 1,016 1,868 12 712 15,367 Balance at end of period $ 7,164 4,809 364 1,016 1,951 12 713 16,029 Loans individually evaluated for impairment $ 10,920 3,941 442 - 718 - 41 16,062 Loans collectively evaluated for impairment 381,897 554,651 21,336 18,179 158,683 319 26,757 1,161,822 Total gross loans $ 392,817 558,592 21,778 18,179 159,401 319 26,798 1,177,884 The following table presents information relating to the Company's internal risk ratings of its loans receivable as of December 31, 2017 and 2016: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total At December 31, 2017 (In Thousands) Substandard $ 7,581 1,135 138 - 1,124 - 1,585 11,563 Watch 4,939 330 401 - 295 - 741 6,706 Pass 427,077 576,975 20,585 19,859 194,423 255 34,371 1,273,545 $ 439,597 578,440 21,124 19,859 195,842 255 36,697 1,291,814 At December 31, 2016 (In Thousands) Substandard $ 12,845 1,427 428 - 717 - 41 15,458 Watch 10,509 3,975 149 436 1,389 - 3,671 20,129 Pass 369,463 553,190 21,201 17,743 157,295 319 23,086 1,142,297 $ 392,817 558,592 21,778 18,179 159,401 319 26,798 1,177,884 Factors that are important to managing overall credit quality include sound loan underwriting and administration, systematic monitoring of existing loans and commitments, effective loan review on an ongoing basis, early identification of potential problems, an appropriate allowance for loan losses, and sound non-accrual and charge-off policies. Our underwriting policies require an officers' loan committee review and approval of all loans in excess of $500,000. In addition, a member of the loan orginator performs a loan review for all loans. Our ability to manage credit risk depends in large part on our ability to properly identify and manage problem loans. To do so, we maintain a loan review system under which our credit management personnel review non-owner occupied one- to four-family, over four-family, construction and land, commercial real estate and commercial loans that individually, or as part of an overall borrower relationship exceed $10.0 million in potential exposure. Loans meeting these criteria are reviewed on an annual basis, or more frequently, if the loan renewal is less than one year. With respect to this review process, management has determined that pass loans include loans that exhibit acceptable financial statements, cash flow and leverage. Watch loans have potential weaknesses that deserve management's attention, and if left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the credit. Substandard loans are considered inadequately protected by the current net worth and paying capacity of the obligor or the collateral pledged. These loans generally have a well-defined weakness that may jeopardize liquidation of the debt and are characterized by the distinct possibility that the Bank will sustain some loss if the deficiencies are not corrected. Finally, a loan is considered to be impaired when it is probable that the Bank will not be able to collect all amounts due according to the contractual terms of the loan agreement. Management has determined that all non-accrual loans and loans modified under troubled debt restructurings meet the definition of an impaired loan. The Company's procedures dictate that an updated valuation must be obtained with respect to underlying collateral at the time a loan is deemed impaired. Updated valuations may also be obtained upon transfer from loans receivable to real estate owned based upon the age of the prior appraisal, changes in market conditions or known changes to the physical condition of the property. Estimated fair values are reduced to account for sales commissions, broker fees, unpaid property taxes and additional selling expenses to arrive at an estimated net realizable value. The adjustment factor is based upon the Company's actual experience with respect to sales of real estate owned over the prior two years. In situations in which we are placing reliance on an appraisal that is more than one year old, an additional adjustment factor is applied to account for downward market pressure since the date of appraisal. The additional adjustment factor is based upon relevant sales data available for our general operating market as well as company-specific historical net realizable values as compared to the most recent appraisal prior to disposition. With respect to over-four family income producing real estate, appraisals are reviewed and estimated collateral values are adjusted by updating significant appraisal assumptions to reflect current real estate market conditions. Significant assumptions reviewed and updated include the capitalization rate, rental income and operating expenses. These adjusted assumptions are based upon recent appraisals received on similar properties as well as on actual experience related to real estate owned and currently under Company management. The following tables present data on impaired loans as of and for the year ended December 31, 2017 and 2016. As of or for the Year Ended December 31, 2017 Recorded Investment Unpaid Principal Reserve Cumulative Charge-Offs Average Recorded Investment Interest Paid YTD Total Impaired with Reserve One- to four-family $ 903 903 77 - 913 52 Multi family - - - - - - Home equity 79 79 44 - 83 6 Construction and land - - - - - - Commercial real estate 34 443 34 409 43 - Consumer - - - - - - Commercial - - - - - - $ 1,016 1,425 155 409 1,039 58 Total Impaired with no Reserve One- to four-family $ 6,515 7,604 - 1,089 6,796 359 Multi family 1,007 1,864 - 857 1,005 94 Home equity 106 106 - - 111 5 Construction and land - - - - - - Commercial real estate 506 506 - - 513 19 Consumer - - - - - - Commercial 26 26 - - 26 - $ 8,160 10,106 - 1,946 8,451 477 Total Impaired One- to four-family $ 7,418 8,507 77 1,089 7,709 411 Multi family 1,007 1,864 - 857 1,005 94 Home equity 185 185 44 - 194 11 Construction and land - - - - - - Commercial real estate 540 949 34 409 556 19 Consumer - - - - - - Commercial 26 26 - - 26 - $ 9,176 11,531 155 2,355 9,490 535 The difference between a loan's recorded investment and the unpaid principal balance represents a partial charge-off resulting from a confirmed loss due to the value of the collateral securing the loan being below the loan balance and management's assessment that the full collection of the loan balance is not likely. When a loan is considered impaired, interest payments received are treated as interest income on a cash basis as long as the remaining book value of the loan (i.e., after charge-off of all identified losses) is deemed to be fully collectible. If the remaining book value is not deemed to be fully collectible, all payments received are applied to unpaid principal. Determination as to the ultimate collectability of the remaining book value is supported by an updated credit department evaluation of the borrower's financial condition and prospects for repayment, including consideration of the borrower's sustained historical repayment performance and other relevant factors. As of or for the Year Ended December 31, 2016 Recorded Investment Unpaid Principal Reserve Cumulative Charge-Offs Average Recorded Investment Interest Paid YTD Total Impaired with Reserve One- to four-family $ 3,007 3,007 499 - 3,063 88 Multi family - - - - - - Home equity 188 188 79 - 198 15 Construction and land - - - - - - Commercial real estate 280 689 83 409 295 15 Consumer - - - - - - Commercial 1 1 1 - 2 - $ 3,476 3,885 662 409 3,558 118 Total Impaired with no Reserve One- to four-family $ 7,913 9,245 - 1,332 8,150 401 Multi family 3,941 4,952 - 1,011 4,005 230 Home equity 254 254 - - 258 9 Construction and land - - - - - - Commercial real estate 438 438 - - 442 13 Consumer - - - - - - Commercial 40 40 - - 46 2 $ 12,586 14,929 - 2,343 12,901 655 Total Impaired One- to four-family $ 10,920 12,252 499 1,332 11,213 489 Multi family 3,941 4,952 - 1,011 4,005 230 Home equity 442 442 79 - 456 24 Construction and land - - - - - - Commercial real estate 718 1,127 83 409 737 28 Consumer - - - - - - Commercial 41 41 1 - 48 2 $ 16,062 18,814 662 2,752 16,459 773 The determination as to whether an allowance is required with respect to impaired loans is based upon an analysis of the value of the underlying collateral and/or the borrower's intent and ability to make all principal and interest payments in accordance with contractual terms. The evaluation process is subject to the use of significant estimates and actual results could differ from estimates. This analysis is primarily based upon third party appraisals and/or a discounted cash flow analysis. In those cases in which no allowance has been provided for an impaired loan, the Company has determined that the estimated value of the underlying collateral exceeds the remaining outstanding balance of the loan. Of the total $8.2 million of impaired loans as of December 31, 2017 for which no allowance has been provided, $1.9 million in charge-offs have been recorded to reduce the unpaid principal balance to an amount that is commensurate with the loan's net realizable value, using the estimated fair value of the underlying collateral. To the extent that further deterioration in property values continues, the Company may have to reevaluate the sufficiency of the collateral servicing these impaired loans resulting in additional provisions to the allowance for loans losses or charge-offs. The following presents data on troubled debt restructurings: As of December 31, 2017 Accruing Non-accruing Total Amount Number Amount Number Amount Number (Dollars in Thousands) One- to four-family $ 2,740 2 $ 1,156 7 $ 3,896 9 Multi family - - 815 3 815 3 Home equity 47 1 - - 47 1 Commercial real estate 290 1 34 1 324 2 $ 3,077 4 $ 2,005 11 $ 5,082 15 As of December 31, 2016 Accruing Non-accruing Total Amount Number Amount Number Amount Number (Dollars in Thousands) One- to four-family $ 3,296 3 $ 2,399 34 $ 5,695 37 Multi family 2,514 1 1,427 5 3,941 6 Home equity 49 1 97 1 146 2 Commercial real estate 295 1 60 1 355 2 $ 6,154 6 $ 3,983 41 $ 10,137 47 Troubled debt restructurings involve granting concessions to a borrower experiencing financial difficulty by modifying the terms of the loan in an effort to avoid foreclosure. Typical restructured terms include six to twelve months of principal forbearance, a reduction in interest rate or both. In no instances have the restructured terms included a reduction of outstanding principal balance. At December 31, 2017, $5.1 million in loans had been modified in troubled debt restructurings and $2.0 million of these loans were included in the non-accrual loan total. The remaining $3.1 million, while meeting the internal requirements for modification in a troubled debt restructuring, were current with respect to payments under their original loan terms at the time of the restructuring and thus, continued to be included with accruing loans. Provided these loans perform in accordance with the modified terms, they will continue to be accounted for on an accrual basis. All loans that have been modified in a troubled debt restructuring are considered to be impaired. As such, an analysis has been performed with respect to all of these loans to determine the need for a valuation reserve. When a loan is expected to perform in accordance with the restructured terms and ultimately return to and perform under contract terms, a valuation allowance is established equal to the excess of the present value of the expected future cash flows under the original contract terms as compared with the modified terms, including an estimated default rate. When there is doubt as to the borrower's ability to perform under the restructured terms or ultimately return to and perform under market terms, a valuation allowance is established equal to the impairment when the carrying amount exceeds fair value of the underlying collateral. As a result of the impairment analysis, a $34,000 valuation allowance has been established as of December 31, 2017 with respect to the $5.1 million in troubled debt restructurings. As of December 31, 2016, $293,000 in valuation allowance had been established with respect to the $10.1 million in troubled debt restructurings. If an updated credit department review indicates no other evidence of elevated credit risk and the borrower completes a minimum of six consecutive contractual payments, the loan is returned to accrual status at that time. The following presents troubled debt restructurings by concession type at December 31, 2017 and 2016: As of December 31, 2017 Performing in accordance with modified terms In Default Total Amount Number Amount Number Amount Number (Dollars in Thousands) Interest reduction and principal forbearance $ 4,022 9 660 2 4,682 11 Principal forbearance 47 1 - - 47 1 Interest reduction 353 3 - - 353 3 $ 4,422 13 660 2 5,082 15 As of December 31, 2016 Performing in accordance with modified terms In Default Total Amount Number Amount Number Amount Number (Dollars in Thousands) Interest reduction and principal forbearance $ 8,221 22 761 2 8,982 24 Principal forbearance 49 1 - - 49 1 Interest reduction 1,106 22 - - 1,106 22 $ 9,376 45 761 2 10,137 47 The following presents data on troubled debt restructurings: For the Year Ended December 31, 2017 December 31, 2016 Amount Number Amount Number (Dollars in Thousands) Loans modified as a troubled debt restructure One- to four-family $ - - - - Multi family - - - - Home equity - - 49 1 $ - - 49 1 There were no troubled debt restructurings for which there was a default during the years ended December 31, 2017 and December 31, 2016. The following table presents data on non-accrual loans: As of December 31, 2017 2016 (Dollars in Thousands) Residential One- to four-family $ 4,677 7,623 Multi family 1,007 1,427 Home equity 107 344 Construction and land - - Commercial real estate 251 422 Commercial 26 41 Consumer - - Total non-accrual loans $ 6,068 9,857 Total non-accrual loans to total loans 0.47 % 0.84 % Total non-accrual loans to total assets 0.34 % 0.55 %

Office Properties and Equipment

Office Properties and Equipment	12 Months Ended
	Dec. 31, 2017
Office Properties and Equipment [Abstract]
Office Properties and Equipment	4) Office Properties and Equipment Office properties and equipment are summarized as follows: December 31, 2017 2016 (In Thousands) Land $ 6,668 6,668 Office buildings and improvements 30,587 30,319 Furniture and equipment 13,585 12,868 50,840 49,855 Less accumulated depreciation (27,899 ) (26,200 ) $ 22,941 23,655 Depreciation of premises and equipment totaled $2.1 million, $2.6 million and $3.1 million for the years ended December 31, 2017, 2016 and 2015, respectively. The Company and certain subsidiaries are obligated under non-cancelable operating leases for other facilities and equipment. Rent and equipment lease expense totaled $4.8 million, $4.4 million and $3.8 million for the years ended December 31, 2017, 2016 and 2015, respectively. The appropriate minimum annual commitments under all non-cancelable lease agreements as of December 31, 2017 are as follows: Operating leases (In Thousands) Within one year $ 2,836 One to two years 1,831 Two to three years 1,112 Three to four years 649 Four through five years 656 After five years 1,005 Total $ 8,089

Real Estate Owned

Real Estate Owned	12 Months Ended
	Dec. 31, 2017
Real Estate Owned [Abstract]
Real Estate Owned [Text Block]	5) Real Estate Owned Real estate owned is summarized as follows: December 31, 2017 2016 (In Thousands) One- to four-family $ 1,330 2,141 Multi-family - - Construction and land 4,582 5,082 Commercial real estate 300 300 Total 6,212 7,523 Valuation allowance at end of period (1,654 ) (1,405 ) Total real estate owned, net $ 4,558 6,118 The following table presents the activity in real estate owned: Year Ended December 31, 2017 2016 (In Thousands) Real estate owned at beginning of period $ 6,118 9,190 Transferred in from loans receivable 2,171 4,590 Sales (3,213 ) (7,006 ) Write downs (514 ) (656 ) Other activity (4 ) - Real estate owned at end of period $ 4,558 6,118 Residential one- to four-family mortgage loans that were in the process of foreclosure were $2.3 million and $3.1 million at December 31, 2017 and December 31, 2016, respectively.

Mortgage Servicing Rights

Mortgage Servicing Rights	12 Months Ended
	Dec. 31, 2017
Mortgage Servicing Rights [Abstract]
Mortgage Servicing Rights	6) Mortgage Servicing Rights The following table presents the activity related to the Company's mortgage servicing rights: Year ended December 31, 2017 2016 (In Thousands) Mortgage servicing rights at beginning of the period $ 2,260 $ 1,422 Additions 998 1,436 Amortization (106 ) (598 ) Sales (2,264 ) - Mortgage servicing rights at end of the period 888 2,260 Valuation allowance at end of period - - Mortgage servicing rights at the end of the period, net $ 888 $ 2,260 During the twelve months ended December 31, 2017, on a consolidated basis, $2.46 billion in residential loans were originated for sale, which excludes the loans originated from Waterstone Mortgage Corporation and purchased by WaterStone Bank. During the same period, sales of loans held for sale totaled $2.53 billion, generating mortgage banking income of $120.0 million. The unpaid principal balance of loans serviced for others was $126.3 million and $318.6 million at December 31, 2017 and December 31, 2016 respectively. These loans are not reflected in the consolidated statements of financial condition. During the twelve months ended December 31, 2017, the Company sold mortgage servicing rights related to $295.1 million in loans receivable and with a book value of $2.3 million for $2.5 million resulting in a gain on sale of $178,000. During the twelve months ended December 31, 2016, the Company did not sell any mortgage servicing rights. The following table shows the estimated future amortization expense for mortgage servicing rights at December 31, 2017 for the periods indicated: (In Thousands) Estimate for the years ended December 31: 2018 $ 132 2019 121 2020 111 2021 101 2022 90 Thereafter 333 Total $ 888

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	7) Deposits The aggregate amount of time deposit accounts with balances greater than $250,000 at December 31, 2017 and 2016 amounted to $45.9 million and $44.5 million, respectively. A summary of interest expense on deposits is as follows: Years ended December 31, 2017 2016 2015 (In Thousands) Interest-bearing demand deposits $ 28 19 20 Money market and savings deposits 401 392 197 Time deposits 7,310 6,953 5,662 $ 7,739 7,364 5,879 A summary of the contractual maturities of time deposits at December 31, 2017 is as follows: (In Thousands) Within one year $ 587,316 One to two years 79,287 Two to three years 17,706 Three to four years 1,407 Four through five years 3,263 $ 688,979

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Borrowings [Abstract]
Borrowings	8) Borrowings Borrowings consist of the following: December 31, 2017 December 31, 2016 Balance Weighted Average Rate Balance Weighted Average Rate (Dollars in Thousands) Short term: Repurchase agreements $ 11,285 4.32 % 8,155 3.52 % Federal Home Loan Bank, Chicago advances 35,000 1.28 % 65,000 0.61 % Long term: Federal Home Loan Bank advances maturing: 2017 - 0.00 % 65,000 3.19 % 2018 65,000 2.97 % 65,000 2.97 % 2021 100,000 0.78 % 100,000 0.78 % 2027 175,000 1.38 % - 0.00 % Repurchase agreements maturing: 2017 - 0.00 % 84,000 3.96 % $ 386,285 1.57 % 387,155 2.27 % The short-term repurchase agreements represents the outstanding portion of a total $35.0 million commitment with one unrelated bank. The short-term repurchase agreement is utilized by Waterstone Mortgage Corporation to finance loans originated for sale. This agreement is secured by the underlying loans being financed. Related interest rates are based upon the note rate associated with the loans being financed. The short-term repurchase agreement had a $11.3 million balance on a total commitment of $35.0 million at December 31, 2017. The $35.0 million short-term advance has with a fixed rate of 1.28% and a maturity date of March 15, 2018. The $65.0 million in advances due in 2018 consist of three advances with fixed rates ranging from 2.73% to 3.11% callable quarterly until maturity. The $100.0 million in advances due in 2021 consist of two advances totaling $50.0 million with fixed rates ranging from 0.67% to 0.73% with a FHLB quarterly call option beginning in June 2018 and one advance for $50.0 million with a fixed rate of 0.85% with a FHLB quarterly call option beginning in September 2018. The $175.0 million in advances due in 2027 consists of one $50.0 million advance with a fixed rate of 1.24% with a FHLB single call option in May 2019, one $50.0 million advance with a fixed rate of 1.23% with a FHLB single call option in June 2019, one $25.0 million advance with a fixed rate of 1.23% with a FHLB single call option in August 2019, and one $50.0 million advance with a fixed rate of 1.73% with a FHLB single call option in December 2019. The Company selects loans that meet underwriting criteria established by the Federal Home Loan Bank Chicago (FHLBC) as collateral for outstanding advances. The Company's borrowings at the FHLBC are limited to 77% of the carrying value of unencumbered one- to four-family mortgage loans, 65% of the carrying value of home equity loans and 75% of the carrying value of over four-family loans. In addition, these advances are collateralized by FHLBC stock of $16.9 million at December 31, 2017 and $13.3 million at December 31, 2016. In the event of prepayment, the Company is obligated to pay all remaining contractual interest on the advance.

Regulatory Capital

Regulatory Capital	12 Months Ended
	Dec. 31, 2017
Regulatory Capital [Abstract]
Regulatory Capital	9) Regulatory Capital The Company and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements, or overall financial performance deemed by the regulators to be inadequate, can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company's financial condition and results of operations. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Bank must meet specific capital guidelines that involve quantitative measures of the Company's and Bank's assets, liabilities, and certain off-balance-sheet items, as calculated under regulatory accounting practices. The Company's and Bank's capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. The Federal Reserve Board and the FDIC issued final rules implementing the Basel III regulatory capital framework and related Dodd-Frank Wall Street Reform and Consumer Protection Act changes. The rules revise minimum capital requirements and adjust prompt corrective action thresholds. The final rules revised the regulatory capital elements, added a new common equity Tier I capital ratio, increased the minimum Tier 1 capital ratio requirements and implemented a new capital conservation buffer. The rules also permitted certain banking organizations to retain, through a one-time election, the existing treatment for accumulated other comprehensive income. The Company and the Bank have made the election to retain the existing treatment for accumulated other comprehensive income. The final rules took effect for the Company and the Bank on January 1, 2015, subject to a transition period for certain parts of the rules. The table below includes the new regulatory capital ratio requirements that became effective on January 1, 2015. Beginning in 2016, an additional capital conservation buffer was added to the minimum requirements for capital adequacy purposes, subject to a three year phase-in period. The capital conservation buffer will be fully phased-in on January 1, 2019 at 2.5%. A banking organization with a conservation buffer of less than 2.5% (or the required phase-in amount in years prior to 2019) will be subject to limitations on capital distributions, including dividend payments and certain discretionary bonus payments to executive officers. At the present time, the ratios for the Company and the Bank are sufficient to meet the fully phased-in conservation buffer. The actual and required capital amounts and ratios as of December 31, 2017 and 2016 are presented in the table below: December 31, 2017 Actual For Capital Adequacy Purposes Minimum Capital Adequacy with Capital Buffer To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars In Thousands) Total capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. $ 426,057 30.75 % 110,829 8.00 % 128,146 9.250 % N/A N/A WaterStone Bank 400,792 28.93 % 110,812 8.00 % 128,127 9.250 % 138,515 10.00 % Tier I capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 411,980 29.74 % 83,122 6.00 % 100,439 7.250 % N/A N/A WaterStone Bank 386,715 27.92 % 83,109 6.00 % 100,424 7.250 % 110,812 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 411,980 29.74 % 62,341 4.50 % 79,658 5.750 % N/A N/A WaterStone Bank 386,715 27.92 % 62,332 4.50 % 79,646 5.750 % 90,035 6.50 % Tier I capital (to average assets) Consolidated Waterstone Financial , Inc. 411,980 22.43 % 73,481 4.00 % N/A N/A N/A N/A WaterStone Bank 386,715 21.10 % 73,304 4.00 % N/A N/A 91,630 5.00 % State of Wisconsin (to total assets) WaterStone Bank 386,715 21.44 % 108,243 6.00 % N/A N/A N/A N/A December 31, 2016 (Dollars In Thousands) Total capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. $ 426,496 32.23 % 105,870 8.00 % 114,141 8.62 % N/A N/A WaterStone Bank 389,602 29.50 % 105,641 8.00 % 113,895 8.62 % 132,052 10.00 % Tier I capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 410,467 31.02 % 79,402 6.00 % 87,673 6.63 % N/A N/A WaterStone Bank 373,573 28.29 % 79,231 6.00 % 87,484 6.63 % 105,641 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 410,467 31.02 % 59,552 4.50 % 67,823 5.12 % N/A N/A WaterStone Bank 373,573 28.29 % 59,423 4.50 % 67,676 5.12 % 85,834 6.50 % Tier I capital (to average assets) Consolidated Waterstone Financial , Inc. 410,467 23.20 % 70,760 4.00 % N/A N/A N/A N/A WaterStone Bank 373,573 21.17 % 70,573 4.00 % N/A N/A 88,216 5.00 % State of Wisconsin (to total assets) WaterStone Bank 373,573 20.90 % 107,247 6.00 % N/A N/A N/A N/A

Stock Based Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2017
Stock Based Compensation [Abstract]
Stock Based Compensation	10) Stock Based Compensation Stock-Based Compensation Plan In 2006, the Company's shareholders approved the 2006 Equity Incentive Plan. All stock awards granted under this plan vest over a period of five years and are required to be settled in shares of the Company's common stock. The exercise price for all stock options granted is equal to the quoted NASDAQ market closing price on the date that the awards were granted and expire ten years after the grant date, if not exercised. All restricted stock grants are issued from previously unissued shares. In 2015, the Company's shareholders approved the 2015 Equity Incentive Plan. A total of 2,530,000 stock options and 1,012,000 restricted shares were approved for award. The 685,000 stock options granted to employees under this plan vest over a period of five years. The 600,000 stock option awards granted to directors under this plan vest over a period of eight years. The exercise price for all stock options granted is equal to the quoted NASDAQ market close price on the date that the awards were granted and expire ten years after the grant date, if not exercised. The 385,500 restricted stock awards granted to employees under this plan vest in five installments over four years with one installment vesting immediately. The 184,000 stock awards granted to directors under this plan vest in eight installments over seven years with one installment vesting immediately. The fair value of the awards were equal to the quoted NASDAQ market closing price on the vest date. Accounting for Stock-Based Compensation Plan The fair value of stock options granted is estimated on the grant date using a Black-Scholes pricing model. The fair value of restricted shares is equal to the quoted NASDAQ market closing price on the date of grant. The fair value of stock grants is recognized as compensation expense on a straight-line basis over the vesting period of the grants. Compensation expense is included in compensation, payroll taxes and other employee benefits in the consolidated statements of income. Assumptions are used in estimating the fair value of stock options granted. The weighted average expected life of the stock options represent the period of time that the options are expected to be outstanding and is based on the historical results from the previous awards. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. The expected volatility is based on the actual volatility of a peer group including Waterstone Financial, Inc. stock from approximately five years prior to issuance date. The following assumptions were used in estimating the fair value of options granted in the years ended December 31, 2017 and 2016. 2017 2016 Minimum Maximum Minimum Maximum Dividend Yield 2.48 % 2.71 % 1.46 % 2.56 % Risk-free interest rate 1.80 % 1.93 % 1.22 % 2.04 % Expected volatility 27.79 % 32.54 % 27.17 % 31.47 % Weighted average expected life 5.3 5.5 4.5 5.5 Weighted average per share value of options $ 4.01 4.63 2.84 4.52 The Company estimates potential forfeitures of stock grants and adjusts compensation expense recorded accordingly. The estimate of forfeitures will be adjusted over the requisite service period to the extent that actual forfeitures differ, or are expected to differ, from such estimates. Changes in estimated forfeitures will be recognized in the period of change and will also impact the amount of stock compensation expense to be recognized in future periods. A summary of the Company's stock option activity for the years ended December 31, 2017, 2016 and 2015 is presented below. Stock Options Shares Weighted Average Exercise Price Weighted Average Years Remaining in Contractual Term Aggregate Intrinsic Value (000's) Outstanding December 31, 2014 970,747 $ 12.33 3.32 797 Options exercisable at December 31, 2014 824,803 14.16 2.67 (829 ) Granted 1,210,000 12.79 1,584 Exercised (62,276 ) 1.90 760 Forfeited (15,424 ) 13.42 10 Outstanding December 31, 2015 2,103,047 12.90 6.15 2,533 Options exercisable at December 31, 2015 810,255 14.25 1.63 (123 ) Granted 55,000 15.54 151 Exercised (736,548 ) 15.04 2,388 Forfeited (59,000 ) 13.15 303 Outstanding December 31, 2016 1,362,499 11.83 7.74 8,785 Options exercisable at December 31, 2016 304,595 9.66 6.44 2,625 Granted 20,000 18.78 (35 ) Exercised (211,205 ) 6.48 2,233 Forfeited (12,195 ) 14.83 27 Outstanding December 31, 2017 1,159,099 12.89 7.24 4,870 Options exercisable at December 31, 2017 331,097 12.53 7.10 1,501 The following table summarizes information about the Company's stock options outstanding at December 31, 2017. Options Outstanding Weighted Average Exercise Price Remaining Life (Years) Options Exercisable Weighted Average Exercise Price Remaining Life (Years) Range of Exercise Prices $ 0.01 - $5.00 8,785 $ 1.73 4.01 8,785 $ 1.73 4.01 $ 5.01 - $10.00 - - - - - - $ 10.01 - $15.00 1,115,314 12.82 7.21 319,312 12.82 7.17 Over $15.01 35,000 18.59 9.07 3,000 18.61 9.08 1,159,099 $ 12.89 7.24 331,097 $ 12.53 7.10 The following table summarizes information about the Company's nonvested stock option activity for the years ended December 31, 2017 and 2016: Stock Options Shares Weighted Average Grant Date Fair Value Nonvested at December 31, 2015 1,292,792 $ 3.09 Granted 55,000 3.46 Vested (230,888 ) 2.86 Forfeited (59,000 ) 3.19 Nonvested at December 31, 2016 1,057,904 3.16 Nonvested at December 31, 2016 1,057,904 3.16 Granted 20,000 4.26 Vested (237,707 ) 2.87 Forfeited (12,195 ) 3.55 Nonvested at December 31, 2017 828,002 3.27 The Company amortizes the expense related to stock options as compensation expense over the vesting period. During the year ended December 31, 2017, 20,000 options were granted, 12,195 were forfeited, of which none were vested. During the year ended December 31, 2016, 55,000 options were granted, 59,000 were forfeited, of which none were vested. During the year ended December 31, 2015, 1,210,000 options were granted and 15,424 were forfeited, of which 8,229 were vested. Expense for the stock options granted of $638,000, $641,000 and $580,000 was recognized during the years ended December 31, 2017, 2016 and 2015, respectively. At December 31, 2017, the Company had $2.2 million in estimated unrecognized compensation costs related to outstanding stock options that is expected to be recognized over a weighted average period of 48 months. The following table summarizes information about the Company's restricted stock shares activity for the years ended December 31, 2017 and 2016: Restricted Stock Shares Weighted Average Grant Date Fair Value Nonvested at December 31, 2015 488,321 $ 12.03 Granted 20,000 14.84 Vested (109,559 ) 11.17 Forfeited (20,000 ) 12.75 Nonvested at December 31, 2016 378,762 12.39 Nonvested at December 31, 2016 378,762 12.39 Granted - - Vested (119,562 ) 11.39 Forfeited - - Nonvested at December 31, 2017 259,200 12.85 The Company amortizes the expense related to restricted stock awards as compensation expense over the vesting period. During the year ended December 31, 2017, no shares of restricted stock were granted and no shares were forfeited. During the year ended December 31, 2016, 20,000 shares of restricted stock were granted and 20,000 shares were forfeited. Expense for the restricted stock awards of $1.3 million, $1.3 million and $2.2 million was recorded for the years ended December 31, 2017, 2016 and 2015, respectively. At December 31, 2017, the Company had $2.4 million of unrecognized compensation expense related to restricted stock shares that is expected to be recognized over a weighted average period of 34 months.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Employee Benefit Plans [Abstract]
Employee Benefit Plans	11) Employee Benefit Plans The Company has two 401(k) profit sharing plans and trusts covering substantially all employees. WaterStone Bank employees over 18 years of age are immediately eligible to participate in the Bank's plan. Waterstone Mortgage employees over 18 years of age are eligible to participate in its plan as of the first of the month following their date of employment. Participating employees may annually contribute pretax compensation in accordance with IRS limits. The Company made matching contributions of $825,000, $759,000 and $595,000 to the plans during the years ended December 31, 2017, 2016 and 2015 respectively.

Employee Stock Ownership Plan

Employee Stock Ownership Plan	12 Months Ended
	Dec. 31, 2017
Employee Stock Ownership Plan [Abstract]
Employee Stock Ownership Plan	12) Employee Stock Ownership Plan All employees are eligible to participate in the WaterStone Bank Employee Stock Ownership Plan (the "Plan") after they attain twenty one years of age and complete twelve consecutive months of service in which they work at least 1,000 hours of service. The Plan debt is secured by shares of the Company. The Company has committed to make annual contributions to the Plan necessary to repay the loan, including interest. During the year ended December 31, 2014, the Plan borrowed an additional $23.8 million from the Company, refinanced the remaining 83,561 shares (related to the 2005 Plan purchase), and purchased an additional 2,024,000 shares of common stock of the Company in the open market. While the shares are not released and allocated to Plan participants until the loan payment is made, the shares are deemed to be earned and are therefore, committed to be released throughout the service period. As such, one-twentieth of the total 2,107,561 shares are scheduled to be released annually as shares are earned over a period of twenty years, beginning with the period ended December 31, 2014. As the debt is repaid, shares are released from collateral and allocated to active participant accounts. The shares pledged as collateral are reported as "Unearned ESOP shares" in the consolidated statement of financial condition. As shares are committed to be released from collateral, the Company reports compensation expense equal to the average fair market price of the shares, and the shares become outstanding for earnings per share computations. Compensation expense attributed to the ESOP was $2.0 million, $1.6 million and $1.4 million, respectively for the years ended December 31, 2017, 2016 and 2015. The aggregate activity in the number of unearned ESOP shares, considering the allocation of those shares committed to be released as of December 31, 2017 and 2016 is as follows: 2017 2016 Beginning ESOP shares 1,791,427 1,896,805 Shares committed to be released (105,378 ) (105,378 ) Unreleased shares 1,686,049 1,791,427 Fair value of unreleased shares (in millions) $ 28.7 33.0

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Income Taxes	13) Income Taxes The provision for income taxes for the year ended December 31, 2017, 2016 and 2015 consists of the following: Years ended December 31, 2017 2016 2015 (In Thousands) Current: Federal $ 13,028 12,255 8,061 State 2,362 2,643 1,342 15,390 14,898 9,403 Deferred: Federal 2,960 1,084 (447 ) State 119 480 293 3,079 1,564 (154 ) Total $ 18,469 16,462 9,249 The income tax provisions differ from that computed at the Federal statutory corporate tax rate for the years ended December 31, 2017, 2016 and 2015 as follows: Years ended December 31, 2017 2016 2015 (Dollars In Thousands) Income before income taxes $ 44,433 41,994 25,819 Tax at Federal statutory rate (35%) 15,552 14,698 9,037 Add (deduct) effect of: State income taxes net of Federal income tax benefit 1,613 2,030 1,063 Cash surrender value of life insurance (632 ) (619 ) (496 ) Non-deductible ESOP and stock option expense 380 268 181 Tax-exempt interest income (449 ) (529 ) (552 ) Non-deductible compensation 280 254 154 Stock option write off - 773 - Deferred tax asset revaluation 2,644 - - Stock compensation (1,074 ) (517 ) - Other 155 104 (138 ) Income tax provision 18,469 16,462 9,249 Effective tax rate 41.6 % 39.2 % 35.8 % The significant components of the Company's net deferred tax assets (liabilities) included in prepaid expenses and other assets are as follows at December 31, 2017 and 2016: December 31, 2017 2016 Gross deferred tax assets: (In Thousands) Fixed assets $ 480 729 Compensation agreements - 27 Restricted stock and stock options 466 638 Allowance for loan losses 3,451 6,109 Repurchase reserve for loans sold 159 183 Real estate owned 993 1,529 Nonaccrual interest 305 531 Capital loss carryforward - 21 Unrealized loss on impaired securities 23 36 Other 192 313 Total gross deferred tax assets 6,069 10,116 Gross deferred tax liabilities: Unrealized gain on securities available for sale, net (11 ) (81 ) Mortgage servicing rights (119 ) (894 ) FHLB stock (232 ) (303 ) Deferred loan fees (703 ) (820 ) Deferred liabilities (1,065 ) (2,098 ) Net deferred tax assets $ 5,004 8,018 The Company had a Wisconsin net operating loss carry forward of $26,000 at December 31, 2017 which will begin to expire in 2028. The Company has no capital loss carryforwards as of December 31, 2017. Under the Internal Revenue Code and Wisconsin Statutes, the Company was permitted to deduct, for tax years beginning before 1988, an annual addition to a reserve for bad debts. This amount differs from the provision for loan losses recorded for financial accounting purposes. Under prior law, bad debt deductions for income tax purposes were included in taxable income of later years only if the bad debt reserves were used for purposes other than to absorb bad debt losses. Because the Company did not intend to use the reserve for purposes other than to absorb losses, no deferred income taxes were provided. Retained earnings at December 31, 2017 include approximately $16.7 million for which no deferred Federal or state income taxes were provided. Deferred income taxes have been provided on certain additions to the tax reserve for bad debts. The Company and its subsidiaries file consolidated federal and combined state tax returns. One subsidiary also files separate state income tax returns in certain states. The Company is no longer subject to state income tax examinations by certain state tax authorities for years before 2013 or subject to federal tax examinations for the years before 2014. As a result of the Tax Cuts and Jobs Act that was enacted into law on December 22, 2017, the Company revalued its net deferred tax asset to reflect the reduction in its federal corporate income tax rate from 35% to 21%. This revaluation resulted in a one-time income tax expense of approximately $2.7 million during the fourth quarter of 2017. The revaluation is subject to adjustment in future periods.

Offsetting of Assets and Liabil

Offsetting of Assets and Liabilities	12 Months Ended
	Dec. 31, 2017
Offsetting of Assets and Liabilities [Abstract]
liabilities subject to an enforceable master netting agreement [Text Block]	14) Offsetting of Assets and Liabilities The Company enters into agreements under which it sells securities subject to an obligation to repurchase the same or similar securities. In addition, the Company enters into agreements under which it sells loans held for sale subject to an obligation to repurchase the same loans. Under these arrangements, the Company may transfer legal control over the assets but still retain effective control through an agreement that both entitles and obligates the Company to repurchase the assets. As a result, these repurchase agreements are accounted for as collateralized financing arrangements (i.e., secured borrowings) and not as a sale and subsequent repurchase of assets. The obligation to repurchase the assets is reflected as a liability in the Company's consolidated statements of condition, while the securities and loans held for sale underlying the repurchase agreements remain in the respective investment securities and loans held for sale asset accounts. In other words, there is no offsetting or netting of the investment securities or loans held for sale assets with the repurchase agreement liabilities. The Company's repurchase agreements are subject to master netting agreements, which sets forth the rights and obligations for repurchase and offset. Under the master netting agreement, the Company is entitled to set off the collateral placed with a single counterparty against obligations owed to that counterparty. The following table presents the liabilities subject to an enforceable master netting agreement as of December 31, 2017 and December 31, 2016. Gross Recognized Liabilities Gross Amounts Offset Net Amounts Presented Gross Amounts Not Offset Net Amount (In thousands) December 31, 2017 Repurchase Agreements Short-term $ 11,285 - 11,285 11,825 - Long-term - - - - - $ 11,285 - 11,285 11,825 - December 31, 2016 Repurchase Agreements Short-term $ 8,155 - 8,155 8,155 - Long-term 84,000 - 84,000 84,000 - $ 92,155 - 92,155 92,155 -

Financial Instruments with Off-

Financial Instruments with Off-Balance Sheet Risk	12 Months Ended
	Dec. 31, 2017
Financial Instruments with Off Balance Sheet Risk [Abstract]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities	15) Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities The Company is a party to financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Those instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The contract or notional amounts of those instruments reflect the extent of involvement the Company has in particular classes of financial instruments. December 31, 2017 2016 (In Thousands) Financial instruments whose contract amounts represent potential credit risk: Commitments to extend credit under first mortgage loans (1) $ 31,543 30,903 Commitments to extend credit under home equity lines of credit 14,972 14,367 Unused portion of construction loans 17,097 21,137 Unused portion of business lines of credit 16,878 15,095 Standby letters of credit 259 333 (1) Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements of the Company. The Company evaluates each customer's creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management's credit evaluation of the counter-party. Collateral obtained generally consists of mortgages on the underlying real estate. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The Company holds mortgages on the underlying real estate as collateral supporting those commitments for which collateral is deemed necessary. The Company has determined that there are no probable losses related to commitments to extend credit or the standby letters of credit as of December 31, 2017 and 2016. In the normal course of business, the Company, or it's subsidiaries are involved in various legal proceedings. In the opinion of management, any liability resulting from pending proceedings would not be expected to have a material adverse effect on the Company's consolidated financial statements. Herrington et al. v. Waterstone Mortgage Corporation Waterstone Mortgage Corporation is a defendant in a class action lawsuit that was filed in the United States District Court for the Western District of Wisconsin and subsequently compelled to arbitration before the American Arbitration Association. The plaintiff class alleged that Waterstone Mortgage Corporation violated certain provisions of the Fair Labor Standards Act (FLSA) and failed to pay loan officers consistent with their employment agreements. On July 5, 2017, the arbitrator issued a Final Award finding Waterstone Mortgage Corporation liable for unpaid minimum wages, overtime, unreimbursed business expenses, and liquidated damages under the FLSA. On December 8, 2017, the District Court confirmed the award in large part, and entered a judgment against Waterstone in the amount of $7,267,919 in damages to Claimants, $3,298,851 in attorney fees and costs, and a $20,000 incentive fee to Plaintiff Herrington, plus post-judgment interest. On February 12, 2018, the District Court awarded post-arbitration fees and costs of approximately $98,000. The judgment is currently being appealed to the Seventh Circuit Court of Appeals, and execution of the judgment is stayed pending appeal. If the judgment is upheld, the Company has estimated that the award, which includes attorney's fees, costs, and interest, could be as high as $11 million. Waterstone Mortgage Corporation will continue to vigorously defend its interests in this matter, including pursuing appropriate appellate processes to challenge the judgment. Although the Company believes there is a basis for appeal, there remains a reasonable possibility that the Court's judgment will be affirmed in whole or in part, with the possible range of loss from $0 to $11 million. Given the pending appeal, we do not believe that the loss is probable at this time, as that term is used in assessing loss contingencies. Accordingly, in accordance with the authoritative guidance in the evaluation of contingencies, the Company has not recorded an accrual related to this matter. Werner et al. v. Waterstone Mortgage Corporation Waterstone Mortgage Corporation is a defendant in a putative collection action lawsuit that was filed on August 4, 2017 in the United States District Court for the Western District of Wisconsin, Werner et al. v. Waterstone Mortgage Corporation

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Financial Instruments [Abstract]
Derivative Financial Instruments	16) Derivative Financial Instruments In connection with its mortgage banking activities, the Company enters into derivative financial instruments as part of its strategy to manage its exposure to changes in interest rates. Mortgage banking derivatives include interest rate lock commitments provided to customers to fund mortgage loans to be sold in the secondary market and forward commitments for the future delivery of such loans. It is the Company's practice to enter into forward commitments for the future delivery of residential mortgage loans when interest rate lock commitments are entered into in order to economically hedge the effect of future changes in interest rates on its commitments to fund the loans as well as on its portfolio of mortgage loans held-for-sale. The Company's mortgage banking derivatives have not been designated as being a hedge relationship. These instruments are used to manage the Company's exposure to interest rate movements and other identified risks but do not meet the strict hedge accounting requirements of ASC 815. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings. The Company does not use derivatives for speculative purposes. Forward commitments to sell mortgage loans represent commitments obtained by the Company from a secondary market agency to purchase mortgages from the Company at specified interest rates and within specified periods of time. Commitments to sell loans are made to mitigate interest rate risk on interest rate lock commitments to originate loans and loans held for sale. At December 31, 2017, the Company had forward commitments to sell mortgage loans with an aggregate notional amount of $281.9 million and interest rate lock commitments with an aggregate notional amount of approximately $159.6 million. The fair value of the forward commitments to sell mortgage loans at December 31, 2017 included a gain of $299,000 that is reported as a component of other assets on the Company's consolidated statement of financial condition. The fair value of the interest rate locks at December 31, 2017 included a gain of $1.7 million that is reported as a component of other assets on the Company's consolidated statements of financial condition. In determining the fair value of its derivative loan commitments, the Company considers the value that would be generated when the loan arising from exercise of the loan commitment is sold in the secondary mortgage market. That value includes the price that the loan is expected to be sold for in the secondary mortgage market. The fair value of these commitments is recorded on the consolidated statements of financial condition with the changes in fair value recorded as a component of mortgage banking income. Residential mortgage loans sold to others are predominantly conventional residential first lien mortgages. The Company's agreements to sell residential mortgage loans in the normal course of business usually require certain representations and warranties on the underlying loans sold related to credit information, loan documentation and collateral, which if subsequently are untrue or breached, could require the Company to repurchase certain loans affected. The Company has only been required to make insignificant repurchases as a result of breaches of representations and warranties. The Company's agreements to sell residential mortgage loans also contain limited recourse provisions. The recourse provisions are limited in that the recourse provision ends after certain payment criteria have been met. With respect to these loans, repurchase could be required if defined delinquency issues arose during the limited recourse period. Given that the underlying loans delivered to buyers are predominantly conventional first lien mortgages and that historical experience shows negligible losses and insignificant repurchase activity, management believes that losses and repurchases under the limited recourse provisions will continue to be insignificant.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements [Abstract]
Fair Value Measurements	17) Fair Values Measurements ASC Topic 820, "Fair Value Measurements and Disclosures" defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. This accounting standard applies to reported balances that are required or permitted to be measured at fair value under existing accounting pronouncements. The standard also emphasizes that fair value (i.e., the price that would be received in an orderly transaction that is not a forced liquidation or distressed sale at the measurement date), among other things, is based on exit price versus entry price, should include assumptions about risk such as nonperformance risk in liability fair values, and is a market-based measurement, not an entity-specific measurement. When considering the assumptions that market participants would use in pricing the asset or liability, this accounting standard establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity's own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy). The fair value hierarchy prioritizes inputs used to measure fair value into three broad levels. Level 1 inputs Level 2 inputs Level 3 inputs In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. The following table presents information about our assets recorded in our consolidated statement of financial position at their fair value on a recurring basis as of December 31, 2017 and December 31, 2016, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. Fair Value Measurements Using December 31, 2017 Level 1 Level 2 Level 3 (In Thousands) Available for sale securities Mortgage-backed securities $ 57,435 - 57,435 - Collateralized mortgage obligations Government sponsored enterprise issued 60,500 - 60,500 - Government sponsored enterprise bonds 2,497 - 2,497 - Municipal securities 63,769 - 63,769 - Other debt securities 14,525 - 14,525 - Certificates of deposit 981 - 981 - Loans held for sale 149,896 - 149,896 - Mortgage banking derivative assets 2,004 - - 2,004 Fair Value Measurements Using December 31, 2016 Level 1 Level 2 Level 3 (In Thousands) Available for sale securities Mortgage-backed securities $ 73,413 - 73,413 - Collateralized mortgage obligations Government sponsored enterprise issued 62,002 - 62,002 - Government sponsored enterprise bonds 2,503 - 2,503 - Municipal securities 70,696 - 70,696 - Other debt securities 16,950 2,541 14,409 - Certificates of deposit 1,231 - 1,231 - Loans held for sale 225,248 - 225,248 - Mortgage banking derivative assets 3,403 - - 3,403 Mortgage banking derivative liabilities 69 - - 69 The following summarizes the valuation techniques for assets recorded in our consolidated statements of financial condition at their fair value on a recurring basis: Available for sale securities – The Company's investment securities classified as available for sale include: mortgage-backed securities, collateralized mortgage obligations, government sponsored enterprise bonds, municipal securities and other debt securities. The fair value of mortgage-backed securities, collateralized mortgage obligations and government sponsored enterprise bonds are determined by a third party valuation source using observable market data utilizing a matrix or multi-dimensional relational pricing model. Standard inputs to these models include observable market data such as benchmark yields, reported trades, broker quotes, issuer spreads, benchmark securities, prepayment models and bid/offer market data. For securities with an early redemption feature, an option adjusted spread model is utilized to adjust the issuer spread. These model and matrix measurements are classified as Level 2 and Level 3 in the fair value hierarchy. The fair value of municipal securities is determined by a third party valuation source using observable market data utilizing a multi-dimensional relational pricing model. Standard inputs to this model include observable market data such as benchmark yields, reported trades, broker quotes, rating updates and issuer spreads. These model measurements are classified as Level 2 in the fair value hierarchy. The fair value of other debt securities, which includes a trust preferred security issued by a financial institution and corporate bonds. The fair value of the trust preferred security is determined through quoted prices in active markets and is classified as Level 1 in the fair value hierarchy. The corporate bond is valued by a third party valuation source using observable market data utilizing a matrix or multi-dimensional relational pricing model. Standard inputs to these models include observable market data such as benchmark yields, reported trades, broker quotes, issuer spreads, benchmark securities, prepayment models and bid/offer market data. Loans held for sale – The Company carries loans held for sale at fair value under the fair value option model. Fair value is generally determined by estimating a gross premium or discount, which is derived from pricing currently observable in the secondary market, principally from observable prices for forward sale commitments. Loans held-for-sale are considered to be Level 2 in the fair value hierarchy of valuation techniques. Mortgage banking derivatives - Mortgage banking derivatives include interest rate lock commitments to originate residential loans held for sale to individual customers and forward commitments to sell residential mortgage loans to various investors. The Company utilizes a valuation model to estimate the fair value of its interest rate lock commitments to originate residential mortgage loans held for sale, which includes applying a pull through rate based upon historical experience and the current interest rate environment and then multiplying by quoted investor prices. The Company also utilizes a valuation model to estimate the fair value of its forward commitments to sell residential loans, which includes matching specific terms and maturities of the forward commitments against applicable investor pricing available. While there are Level 2 and 3 inputs used in the valuation models, the Company has determined that one or more of the inputs significant in the valuation of both of the mortgage banking derivatives fall within Level 3 of the fair value hierarchy. The table below presents reconciliation for all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during 2017 and 2016. Mortgage banking derivatives, net Balance at December 31, 2015 $ 2,188 Transfer into level 3 - Mortgage derivative gain, net 1,146 Balance at December 31, 2016 3,334 Transfer into level 3 - Mortgage derivative loss, net (1,330 ) Balance at December 31, 2017 $ 2,004 Assets Recorded at Fair Value on a Non-recurring Basis The following table presents information about our assets recorded in our consolidated statement of financial position at their fair value on a non-recurring basis as of December 31, 2017 and December 31, 2016, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. Fair Value Measurements Using December 31, 2017 Level 1 Level 2 Level 3 (In Thousands) Impaired loans, net (1) $ 861 - - 861 Real estate owned 4,558 - - 4,558 Fair Value Measurements Using December 31, 2016 Level 1 Level 2 Level 3 (In Thousands) Impaired loans, net (1) $ 2,814 - - 2,814 Real estate owned 6,118 - - 6,118 _________ (1) Loans – We do not record loans at fair value on a recurring basis. On a non-recurring basis, loans determined to be impaired are analyzed to determine whether a collateral shortfall exists, and if such a shortfall exists, are recorded on our consolidated statements of financial condition at net realizable value of the underlying collateral. Fair value is determined based on third party appraisals. Appraised values are adjusted to consider disposition costs and also to take into consideration the age of the most recent appraisal. Given the significance of the adjustments made to appraised values necessary to estimate the fair value of impaired loans, loans that have been deemed to be impaired are considered to be Level 3 in the fair value hierarchy of valuation techniques. At December 31, 2017, loans determined to be impaired with an outstanding balance of $1.0 million were carried net of specific reserves of $155,000 for a fair value of $861,000. At December 31, 2016, loans determined to be impaired with an outstanding balance of $3.5 million were carried net of specific reserves of $662,000 for a fair value of $2.8 million. Impaired loans collateralized by assets which are valued in excess of the net investment in the loan do not require any specific reserves. Real estate owned – On a non-recurring basis, real estate owned, is recorded in our consolidated statements of financial condition at the lower of cost or fair value. Fair value is determined based on third party appraisals and, if less than the carrying value of the foreclosed loan, the carrying value of the real estate owned is adjusted to the fair value. Appraised values are adjusted to consider disposition costs and also to take into consideration the age of the most recent appraisal. Given the significance of the adjustments made to appraised values necessary to estimate the fair value of the properties, real estate owned is considered to be Level 3 in the fair value hierarchy of valuation techniques. Changes in the fair value of real estate owned totaled $514,000 and $656,000 during the year ended December 31, 2017 and 2016, respectively and are recorded in real estate owned expense. At December 31, 2017 and December 31, 2016, real estate owned totaled $4.6 million and $6.1 million, respectively. Mortgage servicing rights - The Company utilizes an independent valuation from a third party which uses a discounted cash flow model to estimate the fair value of mortgage servicing rights. The model utilizes prepayment assumptions to project cash flows related to the mortgage servicing rights based upon the current interest rate environment, which is then discounted to estimate an expected fair value of the mortgage servicing rights. The model considers characteristics specific to the underlying mortgage portfolio, such as: contractually specified servicing fees, prepayment assumptions, delinquency rates, late charges and costs to service. Given the significance of the unobservable inputs utilized in the estimation process, mortgage servicing rights are classified as Level 3 within the fair value hierarchy. The Company records the mortgage servicing rights at the lower of amortized cost or fair value. For the purpose of measuring impairment, mortgage servicing rights are stratified based upon predominant risk characteristics of the underlying loans. At December 31, 2017 and December 31, 2016, there was no impairment identified for mortgage servicing rights. For Level 3 assets and liabilities measured at fair value on a recurring or non-recurring basis as of December 31, 2017, the significant unobservable inputs used in the fair value measurements were as follows: Fair Value at Significant Significant Unobservable Input Value December 31, 2017 Valuation Technique Unobservable Inputs Minimum Value Maximum Value Mortgage banking derivatives $ 2,004 Pricing models Pull through rate 34.4 % 99.8 % Impaired loans 861 Market approach Discount rates applied to appraisals 15.0 % 25.0 % Real estate owned 4,558 Market approach Discount rates applied to appraisals 17.3 % 85.7 % Mortgage servicing rights 1,125 Pricing models Prepayment rate 7.0 % 30.0 % Discount rate 11.0 % 12.0 % Cost to service $ 81.00 $ 204.00 The significant unobservable input used in the fair value measurement of the Company's mortgage banking derivatives, including interest rate lock commitments, is the loan pull through rate. This represents the percentage of loans currently in a lock position which the Company estimates will ultimately close. Generally, the fair value of an interest rate lock commitment will be positively (negatively) impacted when the prevailing interest rate is lower (higher) than the interest rate lock commitment. Generally, an increase in the pull through rate will result in the fair value of the interest rate lock increasing when in a gain position, or decreasing when in a loss position. The pull through rate is largely dependent on the loan processing stage that a loan is currently in and the change in prevailing interest rates from the time of the rate lock. The pull through rate is computed using historical data and the ratio is periodically reviewed by the Company. The significant unobservable inputs used in the fair value measurement of collateral for collateral-dependent impaired loans and real estate owned included in the above table primarily relate to discounting criteria applied to independent appraisals received with respect to the collateral. Discounts applied to the appraisals are dependent on the vintage of the appraisal as well as the marketability of the property. The discount factor is computed using actual realization rates on properties that have been foreclosed upon and liquidated in the open market. The significant unobservable inputs used in the fair value measurement or mortgage servicing rights include the prepayment rate, discount rate and cost to service. The prepayment rate represents the assumed rate of prepayment of the outstanding principal balance of the underlying mortgage notes. Significant increases (decreases) in any of those inputs in isolation could result in a significantly lower (higher) fair value measurement. Although the prepayment rate and discount rate are not directly interrelated, they will generally move in opposite directions. Fair value information about financial instruments follows, whether or not recognized in the consolidated statements of financial condition, for which it is practicable to estimate that value. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. In that regard, the derived fair value estimates cannot be substantiated by comparison to independent markets and, in many cases, could not be realized in immediate settlement of the instrument. Certain financial instruments and all nonfinancial instruments are excluded from its disclosure requirements. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company. The carrying amounts and fair values of the Company's financial instruments consist of the following at December 31, 2017 and December 31, 2016: December 31, 2017 December 31, 2016 Carrying amount Fair Value Carrying amount Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 (In Thousands) Financial Assets Cash and cash equivalents $ 48,607 48,607 39,607 9,000 - 47,217 47,217 34,967 12,250 - Securities available-for-sale 199,707 199,707 - 199,707 - 226,795 226,795 2,541 224,254 - Loans held for sale 149,896 149,896 - 149,896 - 225,248 225,248 - 225,248 - Loans receivable 1,291,814 1,291,142 - - 1,291,142 1,177,884 1,212,967 - - 1,212,967 FHLB stock 16,875 16,875 - 16,875 - 13,275 13,275 - 13,275 - Accrued interest receivable 4,924 4,924 4,924 - - 4,281 4,281 4,281 - - Mortgage servicing rights 888 1,125 - - 1,125 2,260 3,232 - - 3,232 Mortgage banking derivative assets 2,004 2,004 - - 2,004 3,403 3,403 - - 3,403 Financial Liabilities Deposits 967,380 967,558 278,401 689,157 - 949,411 949,825 282,827 666,998 - Advance payments by borrowers for taxes 4,876 4,876 4,876 - - 4,716 4,716 4,716 - - Borrowings 386,285 384,348 - 384,348 - 387,155 390,932 - 390,932 - Accrued interest payable 886 886 886 - - 916 916 916 - - Mortgage banking derivative liabilities - - - - - 69 69 - - 69 The following methods and assumptions were used by the Company in determining its fair value disclosures for financial instruments. Cash and Cash Equivalents The carrying amount reported in the consolidated statements of financial condition for cash and cash equivalents is a reasonable estimate of fair value for these short-term instruments. Securities The fair value of securities is determined by a third party valuation source using observable market data utilizing a matrix or multi-dimensional relational pricing model. Standard inputs to these models include observable market data such as benchmark yields, reported trades, broker quotes, issuer spreads, benchmark securities and bid/offer market data. For securities with an early redemption feature, an option adjusted spread model is utilized to adjust the issuer spread. Prepayment models are used for mortgage related securities with prepayment features. Loans Held for Sale Fair value is estimated using the prices of the Company's existing commitments to sell such loans and/or the quoted market price for commitments to sell similar loans. Loans Receivable Loans determined to be impaired are analyzed to determine whether a collateral shortfall exists, and if such a shortfall exists, are recorded on our consolidated statements of financial condition at fair value. Fair value is determined based on third party appraisals. Appraised values are adjusted to consider disposition costs and also to take into consideration the age of the most recent appraisal. With respect to loans that are not considered to be impaired, fair value is estimated by discounting the future contractual cash flows using discount rates that that reflect a current rate offered to borrowers of similar credit standing for the remaining term to maturity. This method of estimating fair value does not incorporate the exit-price concept of fair value prescribed by ASC 820-10 and generally produces a higher fair value. FHLB Stock For FHLB stock, the carrying amount is the amount at which shares can be redeemed with the FHLB and is a reasonable estimate of fair value. Deposits and Advance Payments by Borrowers for Taxes The fair values for interest-bearing and noninterest-bearing negotiable order of withdrawal accounts, savings accounts, and money market accounts are, by definition, equal to the amount payable on demand at the reporting date (i.e., their carrying amounts). The fair values for fixed-rate certificates of deposit are estimated using a discounted cash flow calculation that applies interest rates currently being offered on certificates of similar remaining maturities to a schedule of aggregated expected monthly maturities of the outstanding certificates of deposit. The advance payments by borrowers for taxes are equal to their carrying amounts at the reporting date. Borrowings Fair values for borrowings are estimated using a discounted cash flow calculation that applies current interest rates to estimated future cash flows of the borrowings. Accrued Interest Payable and Accrued Interest Receivable For accrued interest payable and accrued interest receivable, the carrying amount is a reasonable estimate of fair value. Mortgage Banking Derivative Assets and Liabilities Mortgage banking derivatives include interest rate lock commitments to originate residential loans held for sale to individual customers and forward commitments to sell residential mortgage loans to various investors. The Company relies on a valuation model to estimate the fair value of its interest rate lock commitments to originate residential mortgage loans held for sale, which includes applying a pull through rate based upon historical experience and the current interest rate environment, and then multiplying by quoted investor prices. The Company also relies on a valuation model to estimate the fair value of its forward commitments to sell residential loans, which includes matching specific terms and maturities of the forward commitments against applicable investor pricing available. On the Company's Consolidated Statements of Condition, instruments that have a positive fair value are included in prepaid expenses and other assets, and those instruments that have a negative fair value are included in other liabilities.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	18) Earnings Per Share Earnings per share are computed using the two-class method. Basic earnings per share is computed by dividing net income allocated to common shares by the weighted average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Participating securities include unvested restricted stock awards. Unvested restricted stock awards issued in 2012 are considered participating securities because holders of these securities have the right to receive dividends at the same rate as holders of the Company's common stock. Diluted earnings per share is computed by dividing net income by the weighted average number of common shares outstanding adjusted for the dilutive effect of all potential common shares. For the year ended December 31, 2017 2016 2015 (In Thousands, except per share amounts) Net income $ 25,964 25,532 16,570 Net income available to unvested restricted stockholders - 15 19 Net income available to common stockholders $ 25,964 25,517 16,551 Weighted average shares outstanding 27,467 27,037 29,161 Effect of dilutive potential common shares 432 337 270 Diluted weighted average shares outstanding 27,899 27,374 29,431 Basic income per share $ 0.95 0.94 0.57 Diluted income per share $ 0.93 0.93 0.56

Condensed Parent Company Only S

Condensed Parent Company Only Statements	12 Months Ended
	Dec. 31, 2017
Condensed Parent Company Only Statements [Abstract]
Condensed Parent Company Only Statements	19) Condensed Parent Company Only Statements Statements of Financial Condition December 31, 2017 2016 (In Thousands) Assets Cash and cash equivalents $ 28,954 37,989 Securities available for sale (at fair value) - 2,541 Investment in subsidiaries 386,838 373,705 Other assets 207 170 Total Assets $ 415,999 414,405 Liabilities and shareholders' equity Liabilities: Other liabilities $ 3,895 3,715 Shareholders' equity Preferred Stock (par value $.01 per share), Authorized - 50,000,000 shares in 2017 and 2016, no shares issued - - Common stock (par value $.01 per share), Authorized - 100,000,000 shares in 2017 and in 2016, Issued - 29,501,346 in 2017 and 29,430,123 in 2016, Outstanding - 29,501,346 in 2017 and 29,430,123 in 2016 295 294 Additional paid-in-capital 326,655 322,934 Retained earnings 183,358 184,565 Unearned ESOP shares (18,991 ) (20,178 ) Cost of shares repurchased (6,030,900 in 2017 and 5,908,150 in 2016), at cost (78,736 ) (76,547 ) Accumulated other comprehensive loss (net of taxes) (477 ) (378 ) Total shareholders' equity 412,104 410,690 Total liabilities and shareholders' equity $ 415,999 414,405 Statements of Operations For the year ended December 31, 2017 2016 2015 (In Thousands) Interest income $ 675 716 770 Equity in income of subsidiaries (distributed and undistributed) 25,937 26,309 16,513 Total income 26,612 27,025 17,283 Compensation - - - Professional fees 57 34 24 Other expense 575 553 586 Total expense 632 587 610 Income before income tax expense 25,980 26,438 16,673 Income tax expense 16 906 103 Net income $ 25,964 25,532 16,570 Statements of Cash Flows For the year ended December 31, 2017 2016 2015 (In Thousands) Cash flows from operating activities Net income $ 25,964 25,532 16,570 Adjustments to reconcile net income to net cash provided by operating activities: Amortization of unearned ESOP 1,956 1,633 1,385 Stock based compensation 1,902 1,913 2,817 Deferred income taxes (58 ) 854 49 Equity in earnings of subsidiaries (25,937 ) (26,309 ) (16,513 ) Change in other assets and liabilities 530 (2,031 ) (1,286 ) Net cash provided by operating activities 4,357 1,592 3,022 Net cash used in investing activities - - - Dividends received from subsidiary 14,698 12,783 4,678 Cash dividends on common stock (26,952 ) (6,917 ) (5,869 ) Financing for purchase of ESOP shares - - - Proceeds from stock option exercises 1,052 3,556 113 Proceeds/refunds from stock offering - - - Purchase of common stock returned to authorized but unissued (2,190 ) (3,858 ) (72,748 ) Net (used in) cash provided by financing activities (13,392 ) 5,564 (73,826 ) Net (decrease) increase in cash (9,035 ) 7,156 (70,804 ) Cash and cash equivalents at beginning of year 37,989 30,833 101,637 Cash and cash equivalents at end of year $ 28,954 37,989 30,833

Segment and Related Information

Segment and Related Information	12 Months Ended
	Dec. 31, 2017
Segments and Related Information [Abstract]
Segments and Related Information	20) Segment Reporting Selected financial and descriptive information is required to be provided about reportable operating segments, considering a "management approach" concept as the basis for identifying reportable segments. The management approach is based on the way that management organizes the segments within the enterprise for making operating decisions, allocating resources, and assessing performance. Consequently, the segments are evident from the structure of the enterprise's internal organization, focusing on financial information that an enterprise's chief operating decision-makers use to make decisions about the enterprise's operating matters. The Company has determined that it has two reportable segments: community banking and mortgage banking. The Company's operating segments are presented based on its management structure and management accounting practices. The structure and practices are specific to the Company and therefore, the financial results of the Company's business segments are not necessarily comparable with similar information for other financial institutions. Community Banking The Community Banking segment provides consumer and business banking products and services to customers primarily within Southeastern Wisconsin along with a loan production office in Minneapolis, Minnesota. Within this segment, the following products and services are provided: (1) lending solutions such as residential mortgages, home equity loans and lines of credit, personal and installment loans, real estate financing, business loans, and business lines of credit; (2) deposit and transactional solutions such as checking, credit, debit and pre-paid cards, online banking and bill pay, and money transfer services; (3) investable funds solutions such as savings, money market deposit accounts, IRA accounts, certificates of deposit, and (4) fixed and variable annuities, insurance as well as trust and investment management accounts. Consumer products include loan and deposit products: mortgage, home equity loans and lines, personal term loans, demand deposit accounts, interest bearing transaction accounts and time deposits. Consumer products also include personal investment services. Business banking products include secured and unsecured lines and term loans for working capital, inventory and general corporate use, commercial real estate construction loans, demand deposit accounts, interest bearing transaction accounts and time deposits. Mortgage Banking The Mortgage Banking segment provides residential mortgage loans for the primary purpose of sale in the secondary market. Mortgage banking products and services are provided by offices in 24 states. As of or for the Year ended December 31, 2017 Community Banking Mortgage Banking Holding Company and Other Consolidated (in thousands) Net interest income (loss) $ 50,608 (49 ) 174 50,733 Provision for loan losses (1,300 ) 134 - (1,166 ) Net interest income (loss) after provision for loan losses 51,908 (183 ) 174 51,899 Noninterest income 3,942 122,091 (1,620 ) 124,413 Noninterest expenses: Compensation, payroll taxes, and other employee benefits 17,495 80,077 (488 ) 97,084 Occupancy, office furniture, and equipment 3,127 7,051 - 10,178 FDIC insurance premiums 499 - - 499 Real estate owned 379 - - 379 Other 5,765 18,962 (988 ) 23,739 Total noninterest expenses 27,265 106,090 (1,476 ) 131,879 Income before income taxes 28,585 15,818 30 44,433 Income taxes 12,228 6,225 16 18,469 Net income $ 16,357 9,593 14 25,964 Total Assets $ 1,834,191 173,237 (201,027 ) 1,806,401 As of or for the Year ended December 31, 2016 Community Banking Mortgage Banking Holding Company and Other Consolidated (in thousands) Net interest income $ 42,940 216 288 43,444 Provision for loan losses 200 180 - 380 Net interest income after provision for loan losses 42,740 36 288 43,064 Noninterest income 4,619 122,842 (1,096 ) 126,365 Noninterest expenses: Compensation, payroll taxes, and other employee benefits 17,192 78,288 (424 ) 95,056 Occupancy, office furniture and equipment 3,165 6,182 - 9,347 FDIC insurance premiums 615 - - 615 Real estate owned 399 - - 399 Other 4,979 17,549 (510 ) 22,018 Total noninterest expenses 26,350 102,019 (934 ) 127,435 Income before income taxes 21,009 20,859 126 41,994 Income taxes 7,006 8,550 906 16,462 Net income (loss) $ 14,003 12,309 (780 ) 25,532 Total Assets $ 1,794,697 252,864 (256,942 ) 1,790,619 As of or for the Year ended December 31, 2015 Community Banking Mortgage Banking Holding Company and Other Consolidated (in thousands) Net interest income $ 37,735 759 350 38,844 Provision for loan losses 1,600 365 - 1,965 Net interest income after provision for loan losses 36,135 394 350 36,879 Noninterest income 3,493 101,499 (518 ) 104,474 Noninterest expenses: Compensation, payroll taxes, and other employee benefits 16,462 65,712 (421 ) 81,753 Occupancy, office furniture and equipment 3,278 6,009 - 9,287 FDIC insurance premiums 1,058 - - 1,058 Real estate owned 2,649 15 - 2,664 Other 4,512 16,169 91 20,772 Total noninterest expenses 27,959 87,905 (330 ) 115,534 Income before income taxes 11,669 13,988 162 25,819 Income taxes 3,419 5,727 103 9,249 Net income $ 8,250 8,261 59 16,570 Total Assets $ 1,729,582 188,324 (155,177 ) 1,762,729

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Summary of Significant Accounting Policies [Abstract]
Nature of Operations	a) Nature of Operations The Company is a one-bank holding company with two operating segments – community banking and mortgage banking. WaterStone Bank SSB (the "Bank" or "WaterStone Bank") is principally engaged in the business of attracting deposits from the general public and using such deposits to originate real estate, business and consumer loans. The Bank provides a full range of financial services to customers through branch locations in southeastern Wisconsin. In addition, the Bank has a loan production office in Minneapolis, Minnesota. The Bank is subject to the regulations of certain federal and state agencies and undergoes periodic examinations by those regulatory authorities. The Bank owns a mortgage banking subsidiary that originates residential real estate loans held for sale at various branch offices across the country. Mortgage banking volume fluctuates widely given movements in interest rates. Mortgage banking income is reported as a single line item in the statements of operations while mortgage banking expense is distributed among the various noninterest expense lines. Compensation, payroll taxes and other employee benefits expense varies directly with mortgage banking income.
Principles of Consolidation	b) Principles of Consolidation The consolidated financial statements include the accounts and operations of Waterstone Financial, Inc. and its wholly owned subsidiary, WaterStone Bank. The Bank has the following wholly owned subsidiaries: Wauwatosa Investments, Inc., Waterstone Mortgage Corporation, and Main Street Real Estate Holdings, LLC. All significant intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	c) Use of Estimates The preparation of the consolidated financial statements requires management of the Company to make a number of estimates and assumptions relating to the reported amount of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the period. Significant items subject to such estimates and assumptions include: the allowance for loan losses, income taxes, and fair value measurements. Actual results could differ from those estimates and the current economic environment has increased the degree of uncertainty inherent in those estimates and assumptions.
Cash and Cash Equivalents	e) Cash and Cash Equivalents The Company considers federal funds sold and highly liquid debt instruments with a maturity of three months or less when purchased to be cash equivalents.
Securities	e) Securities Available for Sale Securities At the time of purchase, investment securities are classified as available for sale, as management has the intent and ability to hold such securities for an indefinite period of time, but not necessarily to maturity. Any decision to sell investment securities available for sale would be based on various factors, including, but not limited to asset/liability management strategies, changes in interest rates or prepayment risks, liquidity needs, or regulatory capital considerations. Available for sale securities are carried at fair value, with the unrealized gains and losses, net of deferred tax, reported as a separate component of equity in accumulated other comprehensive income. The cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity or, in the case of mortgage-backed securities and collateralized mortgage obligations, over the estimated life of the security. Such amortization is included in interest income from securities. Realized gains or losses on securities sales (using specific identification method) are included in other income. Declines in value judged to be other than temporary are included in net impairment losses recognized in earnings in the consolidated statements of operations. Other Than Temporary Impairment One of the significant estimates related to securities is the evaluation of investments for other than temporary impairment. The Company assesses investment securities with unrealized loss positions for other than temporary impairment on at least a quarterly basis. When the fair value of an investment is less than its amortized cost at the balance sheet date of the reporting period for which impairment is assessed, the impairment is designated as either temporary or other than temporary. In evaluating other than temporary impairment, management considers the length of time and extent to which the fair value has been less than cost and the expected recovery period of the security, the financial condition and near-term prospects of the issuer, and the intent and ability of the Company to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value in the near term. Declines in the fair value of investment securities below amortized cost are deemed to be other than temporary when the Company cannot assert that it will recover its amortized cost basis, including whether the present value of cash flows expected to be collected is less than the amortized cost basis of the security. If it is more likely than not that the Company will be required to sell the security before recovery or if the Company has the intent to sell, an other than temporary impairment write down is recognized in earnings equal to the difference between the security's amortized cost and its fair value. If it is not more likely than not that the Company will be required to sell the security before recovery and if the Company does not intend to sell, the other than temporary impairment write down is separated into an amount representing credit loss, which is recognized in earnings, and an amount related to other factors, which is recognized as a separate component of equity. Following the recognition of an other than temporary impairment representing credit loss, the book value of an investment less the impairment loss realized becomes the new cost basis. The determination as to whether an other than temporary impairment exists and, if so, the amount considered other than temporarily impaired, or not impaired, is subjective and, therefore, the timing and amount of other than temporary impairments constitute material estimates that are subject to significant change. Federal Home Loan Bank Stock Federal Home Loan Bank ("FHLB") stock is carried at cost, which is the amount that the stock is redeemable by tendering to the FHLB or the amount at which shares can be sold to other FHLB members.
Loans Held for Sale	f) Loans Held for Sale The origination of residential real estate loans is an integral component of the business of the Company. The Company generally sells its originations of long-term fixed interest rate mortgage loans in the secondary market, and on a selective basis, retains the rights to service the loans sold. Gains and losses on the sales of these loans are determined using the specific identification method. Mortgage loans originated for sale are generally sold within 45 days after closing. The Company has elected to carry loans held for sale at fair value. Fair value is generally determined by estimating a gross premium or discount, which is derived from pricing currently observable in the market. The amount by which cost differs from market value is accounted for as a valuation adjustment to the carrying value of the loans. Changes in value are included in mortgage banking income in the consolidated statements of operations. Costs to originate loans held for sale are expensed as incurred and are included on the appropriate noninterest expense lines of the statements of operations. Salaries, commissions and related payroll taxes are the primary costs to originate and comprised approximately 75.5% of total mortgage banking noninterest expense for 2017. The value of mortgage loans held for sale and other residential mortgage loan commitments to customers are hedged by utilizing both best efforts and mandatory forward commitments to sell loans to investors in the secondary market. Such forward commitments are generally entered into at the time when applications are taken to protect the value of the mortgage loans from increases in market interest rates during the period held. The Company recognizes revenue associated with the expected future cash flows of servicing loans at the time a forward loan commitment is made, as required under Securities and Exchange Commission Staff Accounting Bulletin No. 109, Written Loan Commitments Recorded at Fair Value Through Earnings.
Loans Receivable and Related Interest Income	g) Loans Receivable and Related Interest Income Loans are classified as held for investment when management has both the intent and ability to hold the loan for the foreseeable future, or until maturity or payoff. Loans are carried at the principal amount outstanding, net of any unearned income, charge-offs and unamortized deferred fees and costs. Loan origination and commitment fees and certain direct loan origination costs are deferred and the net amount amortized as an adjustment of the related loan yield. Amortization is based on a level-yield method over the contractual life of the related loans or until the loan is paid in full. Loan interest income is recognized on the accrual basis. Accrual of interest is generally discontinued either when reasonable doubt exists as to the full, timely collection of interest or principal, or when a loan becomes contractually past due more than 90 days with respect to interest or principal. At that time, previously accrued and uncollected interest on such loans is reversed and additional income is recorded only to the extent that payments are received and the collection of principal is reasonably assured. Generally, loans are restored to accrual status when the obligation is brought current, has performed in accordance with the contractual terms for a reasonable period of time, and the ultimate collectability of the total contractual principal and interest is no longer in doubt. A loan is accounted for as a troubled debt restructuring if the Company, for economic reasons related to the borrower's financial condition, grants a concession to the borrower that it would not otherwise consider. A troubled debt restructuring typically involves a modification of terms such as a reduction of the stated interest rate, a deferral of principal payments or a combination of both for a temporary period of time. If the borrower was performing in accordance with the original contractual terms at the time of the restructuring, the restructured loan is accounted for on an accruing basis as long as the borrower continues to comply with the modified terms. If the loan was not accounted for on an accrual basis at the time of restructuring, the restructured loan remains in non-accrual status until the loan completes a minimum of six consecutive contractual payments.
Allowance for Loan Losses	h) Allowance for Loan Losses The allowance for loan losses is presented as a reserve against loans and represents the Bank's assessment of probable loan losses inherent in the loan portfolio. The allowance for loan losses is established as losses are estimated to have occurred through a provision for loan losses charged to income. Estimated loan losses are charged against the allowance when the loan balance is confirmed to be uncollectible directly or indirectly by the borrower or upon initiation of a foreclosure action by the Bank. Subsequent recoveries, if any, are credited to the allowance as long as it is within 90 days of being transferred to real estate owned. The allowance provides for probable losses that have been identified with specific customer relationships and for probable losses believed to be inherent in the loan portfolio, but have not been specifically identified. The Bank utilizes its own loss history to estimate inherent losses on loans. Although the Bank allocates portions of the allowance to specific loans and loan types, the entire allowance is available for any loan losses that occur. The Bank evaluates the need for specific valuation allowances on loans that are considered impaired. A loan is considered impaired when, based on current information and events, it is probable that the Bank will not be able to collect all amounts due according to the contractual terms of the loan agreement. Within the loan portfolio, all non-accrual loans and loans modified under troubled debt restructurings have been determined by the Bank to meet the definition of an impaired loan. In addition, other loans may be considered impaired loans. A valuation allowance is established for an amount equal to the impairment when the carrying amount of the loan exceeds the present value of the expected future cash flows, discounted at the loan's original effective interest rate or the fair value of the underlying collateral. The Bank also establishes valuation allowances based on an evaluation of the various risk components that are inherent in the loan portfolio. The risk components that are evaluated include past loan loss experience; the level of non-performing and classified assets; current economic conditions; volume, growth, and composition of the loan portfolio; adverse situations that may affect the borrower's ability to repay; the estimated value of any underlying collateral; regulatory guidance; and other relevant factors. The appropriateness of the allowance for loan losses is approved quarterly by the Bank's board of directors. The allowance reflects management's best estimate of the amount needed to provide for the probable loss on impaired loans, as well as other credit risks of the Bank, and is based on a risk model developed and implemented by management and approved by the Bank's board of directors. Actual results could differ from this estimate, and future additions to the allowance may be necessary based on unforeseen changes in economic conditions. In addition, federal regulators periodically review the Bank's allowance for loan losses. Such regulators have the authority to require the Bank to recognize additions to the allowance at the time of their examination.
Real Estate Owned	i) Real Estate Owned Real estate owned consists of properties acquired through, or in lieu of, loan foreclosure. Real estate owned is transferred into the portfolio at estimated net realizable value. To the extent that the net carrying value of the loan exceeds the estimated fair value of the property at the date of transfer, the excess is charged to the allowance for loan losses within 90 days of being transferred. Subsequent write-downs to reflect current fair market value, as well as gains and losses upon disposition and revenue and expenses incurred in maintaining such properties, are treated as period costs and included in real estate owned in the consolidated statements of operations.
Mortgage Servicing Rights	j) Mortgage Servicing Rights The Company sells residential mortgage loans in the secondary market and, on a selective basis, retains the right to service the loans sold. Upon sale, a mortgage servicing rights asset is capitalized, which represents the then current fair value of future net cash flows expected to be realized for performing servicing activities. Mortgage servicing rights, when purchased, are initially recorded at fair value. Mortgage servicing rights are amortized over the period of estimated net servicing income, and assessed for impairment at each reporting date. Mortgage servicing rights are carried at the lower of the initial capitalized amount, net of accumulated amortization, or estimated fair value, and are included in other assets, net in the consolidated balance sheets. To the extent that the Company sells mortgage servicing rights, a gain is recognized for the amount of which sale proceeds exceed the remaining unamortized cost of the servicing rights that were sold. Gains on sale of mortgage servicing rights are included in other noninterest income in the consolidated statements of operations.
Cash Surrender Value of Life Insurance	k) Cash Surrender Value of Life Insurance The Company purchased bank owned life insurance on the lives of certain employees. The Company is the beneficiary of the life insurance policies. The cash surrender value of life insurance is reported at the amount that would be received in cash if the polices were surrendered. Increases in the cash value of the policies and proceeds of death benefits received are recorded in noninterest income. The increase in cash surrender value of life insurance is not subject to income taxes, as long as the Company has the intent and ability to hold the policies until the death benefits are received.
Office Properties and Equipment	l) Office Properties and Equipment Office properties and equipment, including leasehold improvements and software, are stated at cost, net of depreciation and amortization. Depreciation and amortization are computed on the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the lease term, if shorter than the estimated useful life. Maintenance and repairs are charged to expense as incurred, while additions or major improvements are capitalized and depreciated over their estimated useful lives. Estimated useful lives of the assets are 10 to 30 years for office properties, three to 10 years for equipment, and three years for software. Rent expense related to long-term operating leases is recorded on the accrual basis.
Income Taxes	m) Income Taxes The Company and its subsidiaries file consolidated federal and combined state income tax returns. The provision for income taxes is based upon income in the consolidated financial statements, rather than amounts reported on the income tax returns. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, as well as net operating loss carry forwards. 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 as income or expense in the period that includes the enactment date. The Company evaluates the realizability of its deferred tax assets on a quarterly basis. Under generally accepted accounting principles, a valuation allowance is required to be recognized if it is "more likely than not" that a 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 income, applicable tax planning strategies, and assessments of current and future economic and business conditions. Positions taken in the Company's tax returns may be subject to challenge by the taxing authorities upon examination. The benefit of uncertain tax positions are initially recognized in the financial statements only when it is more likely than not the position will be sustained upon examination by the tax authorities. Such tax positions are both initially and subsequently measured as the largest amount of tax benefit that is greater than 50% likely of being realized upon settlement with the tax authority, assuming full knowledge of the position and all relevant facts. Interest and penalties on income tax uncertainties are classified within income tax expense in the income statement.
Earnings Per Share	n) Earnings Per Share Earnings per share are computed using the two-class method. Basic earnings per share is computed by dividing net income allocated to common shareholders by the weighted average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Diluted earnings per share is computed by dividing net income by the weighted average number of common shares outstanding adjusted for the dilutive effect of all potential common shares. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised. Shares of the Employee Stock Ownership Plan committed to be released are considered outstanding for both common and diluted EPS. Incentive stock compensation awards granted can result in dilution.
Other Comprehensive Income	o) Comprehensive Income Comprehensive income is the total of reported net income and changes in unrealized gains or losses, net of tax, on securities available for sale.
Employee Stock Ownership Plan (ESOP)	p) Employee Stock Ownership Plan (ESOP) Compensation expense under the ESOP is equal to the fair value of common shares released or committed to be released to participants in the ESOP in each respective period. Common stock purchased by the ESOP and not committed to be released to participants is included in the consolidated statements of financial condition at cost as a reduction of shareholders' equity.
Impact of Recent Accounting Pronouncements	q) Impact of Recent Accounting Pronouncements Accounting Standards Codification (ASC) Topic 606 "Revenue from Contracts with Customers." ASC Topic 825 "Financial Instruments." ASC Topic 842 "Leases." ASC Topic 718 "Compensation - Stock Compensation." ASC Topic 326 "Financial Instruments - Credit Losses." ASC Topic 310 "Receivables - Nonrefundable Fees and Other Costs." ASC Topic 220 "Income Statement - Reporting Comprehensive Income."

Securities (Policies)

Securities (Policies)	12 Months Ended
	Dec. 31, 2017
Securities Available for Sale [Abstract]
Impairment of investment securities	The Company reviews the investment securities portfolio on a quarterly basis to monitor its exposure to other-than-temporary impairment. In evaluating whether a security's decline in market value is other-than-temporary, management considers the length of time and extent to which the fair value has been less than cost, financial condition of the issuer and the underlying obligors, quality of credit enhancements, volatility of the fair value of the security, the expected recovery period of the security and ratings agency evaluations. In addition, the Company may also evaluate payment structure, whether there are defaulted payments or expected defaults, prepayment speeds and the value of any underlying collateral.

Derivative Financial Instrume31

Derivative Financial Instruments (Policies)	12 Months Ended
	Dec. 31, 2017
Derivative Financial Instruments [Abstract]
Derivative financial instruments	In connection with its mortgage banking activities, the Company enters into derivative financial instruments as part of its strategy to manage its exposure to changes in interest rates. Mortgage banking derivatives include interest rate lock commitments provided to customers to fund mortgage loans to be sold in the secondary market and forward commitments for the future delivery of such loans. It is the Company's practice to enter into forward commitments for the future delivery of residential mortgage loans when interest rate lock commitments are entered into in order to economically hedge the effect of future changes in interest rates on its commitments to fund the loans as well as on its portfolio of mortgage loans held-for-sale. The Company's mortgage banking derivatives have not been designated as being a hedge relationship. These instruments are used to manage the Company's exposure to interest rate movements and other identified risks but do not meet the strict hedge accounting requirements of ASC 815. Changes in the fair value of derivatives not designated in hedging relationships are recorded directly in earnings. The Company does not use derivatives for speculative purposes. Forward commitments to sell mortgage loans represent commitments obtained by the Company from a secondary market agency to purchase mortgages from the Company at specified interest rates and within specified periods of time. Commitments to sell loans are made to mitigate interest rate risk on interest rate lock commitments to originate loans and loans held for sale. At December 31, 2017, the Company had forward commitments to sell mortgage loans with an aggregate notional amount of $281.9 million and interest rate lock commitments with an aggregate notional amount of approximately $159.6 million. The fair value of the forward commitments to sell mortgage loans at December 31, 2017 included a gain of $299,000 that is reported as a component of other assets on the Company's consolidated statement of financial condition. The fair value of the interest rate locks at December 31, 2017 included a gain of $1.7 million that is reported as a component of other assets on the Company's consolidated statements of financial condition. In determining the fair value of its derivative loan commitments, the Company considers the value that would be generated when the loan arising from exercise of the loan commitment is sold in the secondary mortgage market. That value includes the price that the loan is expected to be sold for in the secondary mortgage market. The fair value of these commitments is recorded on the consolidated statements of financial condition with the changes in fair value recorded as a component of mortgage banking income. Residential mortgage loans sold to others are predominantly conventional residential first lien mortgages. The Company's agreements to sell residential mortgage loans in the normal course of business usually require certain representations and warranties on the underlying loans sold related to credit information, loan documentation and collateral, which if subsequently are untrue or breached, could require the Company to repurchase certain loans affected. The Company has only been required to make insignificant repurchases as a result of breaches of representations and warranties. The Company's agreements to sell residential mortgage loans also contain limited recourse provisions. The recourse provisions are limited in that the recourse provision ends after certain payment criteria have been met. With respect to these loans, repurchase could be required if defined delinquency issues arose during the limited recourse period. Given that the underlying loans delivered to buyers are predominantly conventional first lien mortgages and that historical experience shows negligible losses and insignificant repurchase activity, management believes that losses and repurchases under the limited recourse provisions will continue to be insignificant.

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Securities Available for Sale [Abstract]
Amortized cost and fair values of investment in securities available for sale	The amortized cost and fair value of the Company's investment in securities follow: December 31, 2017 Amortized cost Gross unrealized gains Gross unrealized losses Fair value (In Thousands) Mortgage-backed securities $ 57,351 324 (240 ) 57,435 Collateralized mortgage obligations Government sponsored enterprise issued 61,313 3 (816 ) 60,500 Mortgage related securities 118,664 327 (1,056 ) 117,935 Government sponsored enterprise bonds 2,500 – (3 ) 2,497 Municipal securities 62,516 1,334 (81 ) 63,769 Other debt securities 15,005 12 (492 ) 14,525 Debt securities 80,021 1,346 (576 ) 80,791 Certificates of deposit 980 1 - 981 $ 199,665 1,674 (1,632 ) 199,707 December 31, 2016 Amortized cost Gross unrealized gains Gross unrealized losses Fair value (In Thousands) Mortgage-backed securities $ 72,858 798 (243 ) 73,413 Collateralized mortgage obligations Government sponsored enterprise issued 62,297 70 (365 ) 62,002 Mortgage related securities 135,155 868 (608 ) 135,415 Government sponsored enterprise bonds 2,500 4 (1 ) 2,503 Municipal securities 70,311 685 (300 ) 70,696 Other debt securities 17,399 154 (603 ) 16,950 Debt securities 90,210 843 (904 ) 90,149 Certificates of deposit 1,225 7 (1 ) 1,231 $ 226,590 1,718 (1,513 ) 226,795
Amortized cost and fair values of investment securities by contractual maturity	The amortized cost and fair value of securities at December 31, 2017, by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because issuers or borrowers may have the right to prepay obligations with or without prepayment penalties. December 31, 2017 Amortized cost Fair value (In Thousands) Debt securities: Due within one year $ 10,204 10,180 Due after one year through five years 22,312 22,330 Due after five years through ten years 36,309 37,461 Due after ten years 12,176 11,801 Mortgage-related securities 118,664 117,935 $ 199,665 199,707
Total proceeds and gross gains and losses from sales of investment securities available for sale	Total proceeds and gross gains and losses from sales of investment securities available for sale for each of periods listed below. December 31, 2017 2016 2015 (In Thousands) Gross gains $ - - 44 Gross losses (107 ) - - Gains on sale of investment securities, net $ (107 ) - 44 Proceeds from sales of investment securities $ 448 - 1,034
Fair value and gross unrealized losses on securities available for sale and in a continuous unrealized loss position	Gross unrealized losses on securities available for sale and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows: December 31, 2017 Less than 12 months 12 months or longer Total Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss (In Thousands) Mortgage-backed securities $ 35,136 (143 ) 4,464 (97 ) 39,600 (240 ) Collateralized mortgage obligations Government sponsored enterprise issued 37,949 (348 ) 21,651 (468 ) 59,600 (816 ) Government sponsored enterprise bonds 2,497 (3 ) - - 2,497 (3 ) Municipal securities 17,096 (80 ) 100 (1 ) 17,196 (81 ) Other debt securities - - 9,508 (492 ) 9,508 (492 ) Certificates of deposit - - - - – - $ 92,678 (574 ) 35,723 (1,058 ) 128,401 (1,632 ) December 31, 2016 Less than 12 months 12 months or longer Total Fair value Unrealized loss Fair value Unrealized loss Fair value Unrealized loss (In Thousands) Mortgage-backed securities $ 23,433 (222 ) 1,068 (21 ) 24,501 (243 ) Collateralized mortgage obligations Government sponsored enterprise issued 39,395 (365 ) - - 39,395 (365 ) Government sponsored enterprise bonds 2,000 (1 ) - - 2,000 (1 ) Municipal securities 32,141 (300 ) - - 32,141 (300 ) Other debt securities - - 9,397 (603 ) 9,397 (603 ) Certificates of deposit 489 (1 ) - - 489 (1 ) $ 97,458 (889 ) 10,465 (624 ) 107,923 (1,513 )
Change in other-than-temporary credit related impairment charges on collateralized mortgage obligations for which a portion of OTTI related to other factors was recognized in other comprehensive loss	The following table presents the change in other-than-temporary credit related impairment charges on municipal securities for which a portion of the other-than-temporary impairments related to other factors was recognized in other comprehensive loss. (In Thousands) Credit-related impairments on securities as of December 31, 2015 $ 117 Credit related impairments related to a security for which other-than-temporary impairment was not previously recognized $ - Decrease in credit related impairments related to securities for which an other-than-temporary impairment was previously recognized (23 ) Credit-related impairments on securities as of December 31, 2016 $ 94 Credit related impairments related to a security for which other-than-temporary impairment was not previously recognized $ - Increase in credit related impairments related to securities for which an other-than-temporary impairment was previously recognized - Credit-related impairments on securities as of December 31, 2017 $ 94

Loans Receivable (Tables)

Loans Receivable (Tables)	12 Months Ended
	Dec. 31, 2017
Loan Receivable [Abstract]
Schedule of Components of Loans Receivable	Loans receivable at December 31, 2017 and 2016 are summarized as follows: December 31, 2017 2016 Mortgage loans: (In Thousands) Residential real estate: One- to four-family $ 439,597 392,817 Multi family 578,440 558,592 Home equity 21,124 21,778 Construction and land 19,859 18,179 Commercial real estate 195,842 159,401 Consumer 255 319 Commercial loans 36,697 26,798 Total loans receivable $ 1,291,814 1,177,884
Analysis of Past Due Loans Receivable	An analysis of past due loans receivable as of December 31, 2017 and 2016 follows: As of December 31, 2017 1-59 Days Past Due (1) 60-89 Days Past Due (2) Greater Than 90 Days Total Past Due Current (3) Total Loans Mortgage loans: (In Thousands) Residential real estate: One- to four-family $ 1,494 146 3,516 5,156 434,441 439,597 Multi family - 128 192 320 578,120 578,440 Home equity 68 - 56 124 21,000 21,124 Construction and land - - - - 19,859 19,859 Commercial real estate - - 184 184 195,658 195,842 Consumer - - - - 255 255 Commercial loans - 42 26 68 36,629 36,697 Total $ 1,562 316 3,974 5,852 1,285,962 1,291,814 As of December 31, 2016 1-59 Days Past Due (1) 60-89 Days Past Due (2) Greater Than 90 Days Total Past Due Current (3) Total Loans Mortgage loans: (In Thousands) Residential real estate: One- to four-family $ 2,403 7 4,623 7,033 385,784 392,817 Multi family 376 - 401 777 557,815 558,592 Home equity 82 - 35 117 21,661 21,778 Construction and land - - - - 18,179 18,179 Commercial real estate - - 203 203 159,198 159,401 Consumer - - - - 319 319 Commercial loans 42 - 27 69 26,729 26,798 Total $ 2,903 7 5,289 8,199 1,169,685 1,177,884 (1) Includes $241,000 and $148,000 for December 31, 2017 and 2016, respectively, which are on non-accrual status. (2) Includes $15,000 and $- for December 31, 2017 and 2016, respectively, which are on non-accrual status. (3) Includes $1.8 million and $4.4 million for December 31, 2017 and 2016, respectively, which are on non-accrual status.
Allowance for Loan Losses	A summary of the activity for the years ended 2017, 2016 and 2015 in the allowance for loan losses follows: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total (In Thousands) Year ended December 31, 2017 Balance at beginning of period $ 7,164 4,809 364 1,016 1,951 12 713 16,029 Provision for loan losses (299 ) (494 ) (34 ) (215 ) (64 ) (3 ) (57 ) (1,166 ) Charge-offs (1,364 ) (92 ) - (14 ) (7 ) - - (1,477 ) Recoveries 293 208 26 162 1 1 - 691 Balance at end of period $ 5,794 4,431 356 949 1,881 10 656 14,077 Year ended December 31, 2016 Balance at beginning of period $ 7,763 5,000 433 904 1,680 9 396 16,185 Provision for loan losses (407 ) 146 7 43 271 3 317 380 Charge-offs (1,003 ) (489 ) (112 ) (3 ) - - - (1,607 ) Recoveries 811 152 36 72 - - - 1,071 Balance at end of period $ 7,164 4,809 364 1,016 1,951 12 713 16,029 Year ended December 31, 2015 Balance at beginning of period $ 9,877 5,358 422 687 1,951 8 403 18,706 Provision for loan losses 1,092 931 (27 ) 243 (266 ) (1 ) (7 ) 1,965 Charge-offs (3,855 ) (2,281 ) (72 ) (84 ) (45 ) (3 ) - (6,340 ) Recoveries 649 992 110 58 40 5 - 1,854 Balance at end of period $ 7,763 5,000 433 904 1,680 9 396 16,185
Schedule of Allowance for Loan Loss for Loans Evaluated Individually and Collectively For Impairment	A summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class as of the year ended December 31, 2017 follows: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total (In Thousands) Allowance related to loans individually evaluated for impairment $ 77 - 44 - 34 - - 155 Allowance related to loans collectively evaluated for impairment 5,717 4,431 312 949 1,847 10 656 13,922 Balance at end of period $ 5,794 4,431 356 949 1,881 10 656 14,077 Loans individually evaluated for impairment $ 7,418 1,007 185 - 540 - 26 9,176 Loans collectively evaluated for impairment 432,179 577,433 20,939 19,859 195,302 255 36,671 1,282,638 Total gross loans $ 439,597 578,440 21,124 19,859 195,842 255 36,697 1,291,814 A summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class as of the year ended December 31, 2016 follows: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total (In Thousands ) Allowance related to loans individually evaluated for impairment $ 499 - 79 - 83 - 1 662 Allowance related to loans collectively evaluated for impairment 6,665 4,809 285 1,016 1,868 12 712 15,367 Balance at end of period $ 7,164 4,809 364 1,016 1,951 12 713 16,029 Loans individually evaluated for impairment $ 10,920 3,941 442 - 718 - 41 16,062 Loans collectively evaluated for impairment 381,897 554,651 21,336 18,179 158,683 319 26,757 1,161,822 Total gross loans $ 392,817 558,592 21,778 18,179 159,401 319 26,798 1,177,884
Internal Risk Rating of Loans Receivable	The following table presents information relating to the Company's internal risk ratings of its loans receivable as of December 31, 2017 and 2016: One- to Four- Family Multi Family Home Equity Construction and Land Commercial Real Estate Consumer Commercial Total At December 31, 2017 (In Thousands) Substandard $ 7,581 1,135 138 - 1,124 - 1,585 11,563 Watch 4,939 330 401 - 295 - 741 6,706 Pass 427,077 576,975 20,585 19,859 194,423 255 34,371 1,273,545 $ 439,597 578,440 21,124 19,859 195,842 255 36,697 1,291,814 At December 31, 2016 (In Thousands) Substandard $ 12,845 1,427 428 - 717 - 41 15,458 Watch 10,509 3,975 149 436 1,389 - 3,671 20,129 Pass 369,463 553,190 21,201 17,743 157,295 319 23,086 1,142,297 $ 392,817 558,592 21,778 18,179 159,401 319 26,798 1,177,884
Impaired Loan Receivables	The following tables present data on impaired loans as of and for the year ended December 31, 2017 and 2016. As of or for the Year Ended December 31, 2017 Recorded Investment Unpaid Principal Reserve Cumulative Charge-Offs Average Recorded Investment Interest Paid YTD Total Impaired with Reserve One- to four-family $ 903 903 77 - 913 52 Multi family - - - - - - Home equity 79 79 44 - 83 6 Construction and land - - - - - - Commercial real estate 34 443 34 409 43 - Consumer - - - - - - Commercial - - - - - - $ 1,016 1,425 155 409 1,039 58 Total Impaired with no Reserve One- to four-family $ 6,515 7,604 - 1,089 6,796 359 Multi family 1,007 1,864 - 857 1,005 94 Home equity 106 106 - - 111 5 Construction and land - - - - - - Commercial real estate 506 506 - - 513 19 Consumer - - - - - - Commercial 26 26 - - 26 - $ 8,160 10,106 - 1,946 8,451 477 Total Impaired One- to four-family $ 7,418 8,507 77 1,089 7,709 411 Multi family 1,007 1,864 - 857 1,005 94 Home equity 185 185 44 - 194 11 Construction and land - - - - - - Commercial real estate 540 949 34 409 556 19 Consumer - - - - - - Commercial 26 26 - - 26 - $ 9,176 11,531 155 2,355 9,490 535 The difference between a loan's recorded investment and the unpaid principal balance represents a partial charge-off resulting from a confirmed loss due to the value of the collateral securing the loan being below the loan balance and management's assessment that the full collection of the loan balance is not likely. When a loan is considered impaired, interest payments received are treated as interest income on a cash basis as long as the remaining book value of the loan (i.e., after charge-off of all identified losses) is deemed to be fully collectible. If the remaining book value is not deemed to be fully collectible, all payments received are applied to unpaid principal. Determination as to the ultimate collectability of the remaining book value is supported by an updated credit department evaluation of the borrower's financial condition and prospects for repayment, including consideration of the borrower's sustained historical repayment performance and other relevant factors. As of or for the Year Ended December 31, 2016 Recorded Investment Unpaid Principal Reserve Cumulative Charge-Offs Average Recorded Investment Interest Paid YTD Total Impaired with Reserve One- to four-family $ 3,007 3,007 499 - 3,063 88 Multi family - - - - - - Home equity 188 188 79 - 198 15 Construction and land - - - - - - Commercial real estate 280 689 83 409 295 15 Consumer - - - - - - Commercial 1 1 1 - 2 - $ 3,476 3,885 662 409 3,558 118 Total Impaired with no Reserve One- to four-family $ 7,913 9,245 - 1,332 8,150 401 Multi family 3,941 4,952 - 1,011 4,005 230 Home equity 254 254 - - 258 9 Construction and land - - - - - - Commercial real estate 438 438 - - 442 13 Consumer - - - - - - Commercial 40 40 - - 46 2 $ 12,586 14,929 - 2,343 12,901 655 Total Impaired One- to four-family $ 10,920 12,252 499 1,332 11,213 489 Multi family 3,941 4,952 - 1,011 4,005 230 Home equity 442 442 79 - 456 24 Construction and land - - - - - - Commercial real estate 718 1,127 83 409 737 28 Consumer - - - - - - Commercial 41 41 1 - 48 2 $ 16,062 18,814 662 2,752 16,459 773
Troubled Debt Restructurings on Loan Receivables	The following presents data on troubled debt restructurings: As of December 31, 2017 Accruing Non-accruing Total Amount Number Amount Number Amount Number (Dollars in Thousands) One- to four-family $ 2,740 2 $ 1,156 7 $ 3,896 9 Multi family - - 815 3 815 3 Home equity 47 1 - - 47 1 Commercial real estate 290 1 34 1 324 2 $ 3,077 4 $ 2,005 11 $ 5,082 15 As of December 31, 2016 Accruing Non-accruing Total Amount Number Amount Number Amount Number (Dollars in Thousands) One- to four-family $ 3,296 3 $ 2,399 34 $ 5,695 37 Multi family 2,514 1 1,427 5 3,941 6 Home equity 49 1 97 1 146 2 Commercial real estate 295 1 60 1 355 2 $ 6,154 6 $ 3,983 41 $ 10,137 47
Schedule of Troubled Debt Restructurings by Concession Type	The following presents troubled debt restructurings by concession type at December 31, 2017 and 2016: As of December 31, 2017 Performing in accordance with modified terms In Default Total Amount Number Amount Number Amount Number (Dollars in Thousands) Interest reduction and principal forbearance $ 4,022 9 660 2 4,682 11 Principal forbearance 47 1 - - 47 1 Interest reduction 353 3 - - 353 3 $ 4,422 13 660 2 5,082 15 As of December 31, 2016 Performing in accordance with modified terms In Default Total Amount Number Amount Number Amount Number (Dollars in Thousands) Interest reduction and principal forbearance $ 8,221 22 761 2 8,982 24 Principal forbearance 49 1 - - 49 1 Interest reduction 1,106 22 - - 1,106 22 $ 9,376 45 761 2 10,137 47
Schedule of Data on Troubled Debt Restructurings	The following presents data on troubled debt restructurings: For the Year Ended December 31, 2017 December 31, 2016 Amount Number Amount Number (Dollars in Thousands) Loans modified as a troubled debt restructure One- to four-family $ - - - - Multi family - - - - Home equity - - 49 1 $ - - 49 1 There were no troubled debt restructurings for which there was a default during the years ended December 31, 2017 and December 31, 2016.
Schedule of Loans Receivables, Non Accrual Status	The following table presents data on non-accrual loans: As of December 31, 2017 2016 (Dollars in Thousands) Residential One- to four-family $ 4,677 7,623 Multi family 1,007 1,427 Home equity 107 344 Construction and land - - Commercial real estate 251 422 Commercial 26 41 Consumer - - Total non-accrual loans $ 6,068 9,857 Total non-accrual loans to total loans 0.47 % 0.84 % Total non-accrual loans to total assets 0.34 % 0.55 %

Office Properties and Equipme34

Office Properties and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Office Properties and Equipment [Abstract]
Schedule of office properties and equipment	Office properties and equipment are summarized as follows: December 31, 2017 2016 (In Thousands) Land $ 6,668 6,668 Office buildings and improvements 30,587 30,319 Furniture and equipment 13,585 12,868 50,840 49,855 Less accumulated depreciation (27,899 ) (26,200 ) $ 22,941 23,655
Minimum annual commitments under all non-cancelable lease agreements	The Company and certain subsidiaries are obligated under non-cancelable operating leases for other facilities and equipment. Rent and equipment lease expense totaled $4.8 million, $4.4 million and $3.8 million for the years ended December 31, 2017, 2016 and 2015, respectively. The appropriate minimum annual commitments under all non-cancelable lease agreements as of December 31, 2017 are as follows: Operating leases (In Thousands) Within one year $ 2,836 One to two years 1,831 Two to three years 1,112 Three to four years 649 Four through five years 656 After five years 1,005 Total $ 8,089

Real Estate Owned (Tables)

Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2017
Real Estate Owned [Abstract]
Summary of real estate owned	Real estate owned is summarized as follows: December 31, 2017 2016 (In Thousands) One- to four-family $ 1,330 2,141 Multi-family - - Construction and land 4,582 5,082 Commercial real estate 300 300 Total 6,212 7,523 Valuation allowance at end of period (1,654 ) (1,405 ) Total real estate owned, net $ 4,558 6,118 The following table presents the activity in real estate owned: Year Ended December 31, 2017 2016 (In Thousands) Real estate owned at beginning of period $ 6,118 9,190 Transferred in from loans receivable 2,171 4,590 Sales (3,213 ) (7,006 ) Write downs (514 ) (656 ) Other activity (4 ) - Real estate owned at end of period $ 4,558 6,118 Residential one- to four-family mortgage loans that were in the process of foreclosure were $2.3 million and $3.1 million at December 31, 2017 and December 31, 2016, respectively.

Mortgage Servicing Rights (Tabl

Mortgage Servicing Rights (Tables)	12 Months Ended
	Dec. 31, 2017
Mortgage Servicing Rights [Abstract]
Mortgage Servicing Rights Activity	The following table presents the activity related to the Company's mortgage servicing rights: Year ended December 31, 2017 2016 (In Thousands) Mortgage servicing rights at beginning of the period $ 2,260 $ 1,422 Additions 998 1,436 Amortization (106 ) (598 ) Sales (2,264 ) - Mortgage servicing rights at end of the period 888 2,260 Valuation allowance at end of period - - Mortgage servicing rights at the end of the period, net $ 888 $ 2,260 During the twelve months ended December 31, 2017, on a consolidated basis, $2.46 billion in residential loans were originated for sale, which excludes the loans originated from Waterstone Mortgage Corporation and purchased by WaterStone Bank. During the same period, sales of loans held for sale totaled $2.53 billion, generating mortgage banking income of $120.0 million. The unpaid principal balance of loans serviced for others was $126.3 million and $318.6 million at December 31, 2017 and December 31, 2016 respectively. These loans are not reflected in the consolidated statements of financial condition. During the twelve months ended December 31, 2017, the Company sold mortgage servicing rights related to $295.1 million in loans receivable and with a book value of $2.3 million for $2.5 million resulting in a gain on sale of $178,000. During the twelve months ended December 31, 2016, the Company did not sell any mortgage servicing rights.
Estimated Amortization Expense of Mortgage Servicing Rights	The following table shows the estimated future amortization expense for mortgage servicing rights at December 31, 2017 for the periods indicated: (In Thousands) Estimate for the years ended December 31: 2018 $ 132 2019 121 2020 111 2021 101 2022 90 Thereafter 333 Total $ 888

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Summary of interest expense on deposits	A summary of interest expense on deposits is as follows: Years ended December 31, 2017 2016 2015 (In Thousands) Interest-bearing demand deposits $ 28 19 20 Money market and savings deposits 401 392 197 Time deposits 7,310 6,953 5,662 $ 7,739 7,364 5,879
Contractual maturities of time deposits	A summary of the contractual maturities of time deposits at December 31, 2017 is as follows: (In Thousands) Within one year $ 587,316 One to two years 79,287 Two to three years 17,706 Three to four years 1,407 Four through five years 3,263 $ 688,979

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Borrowings [Abstract]
Borrowings	Borrowings consist of the following: December 31, 2017 December 31, 2016 Balance Weighted Average Rate Balance Weighted Average Rate (Dollars in Thousands) Short term: Repurchase agreements $ 11,285 4.32 % 8,155 3.52 % Federal Home Loan Bank, Chicago advances 35,000 1.28 % 65,000 0.61 % Long term: Federal Home Loan Bank advances maturing: 2017 - 0.00 % 65,000 3.19 % 2018 65,000 2.97 % 65,000 2.97 % 2021 100,000 0.78 % 100,000 0.78 % 2027 175,000 1.38 % - 0.00 % Repurchase agreements maturing: 2017 - 0.00 % 84,000 3.96 % $ 386,285 1.57 % 387,155 2.27 %

Regulatory Capital (Tables)

Regulatory Capital (Tables)	12 Months Ended
	Dec. 31, 2017
Regulatory Capital [Abstract]
Actual and required capital amounts and ratios	The actual and required capital amounts and ratios as of December 31, 2017 and 2016 are presented in the table below: December 31, 2017 Actual For Capital Adequacy Purposes Minimum Capital Adequacy with Capital Buffer To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio Amount Ratio (Dollars In Thousands) Total capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. $ 426,057 30.75 % 110,829 8.00 % 128,146 9.250 % N/A N/A WaterStone Bank 400,792 28.93 % 110,812 8.00 % 128,127 9.250 % 138,515 10.00 % Tier I capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 411,980 29.74 % 83,122 6.00 % 100,439 7.250 % N/A N/A WaterStone Bank 386,715 27.92 % 83,109 6.00 % 100,424 7.250 % 110,812 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 411,980 29.74 % 62,341 4.50 % 79,658 5.750 % N/A N/A WaterStone Bank 386,715 27.92 % 62,332 4.50 % 79,646 5.750 % 90,035 6.50 % Tier I capital (to average assets) Consolidated Waterstone Financial , Inc. 411,980 22.43 % 73,481 4.00 % N/A N/A N/A N/A WaterStone Bank 386,715 21.10 % 73,304 4.00 % N/A N/A 91,630 5.00 % State of Wisconsin (to total assets) WaterStone Bank 386,715 21.44 % 108,243 6.00 % N/A N/A N/A N/A December 31, 2016 (Dollars In Thousands) Total capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. $ 426,496 32.23 % 105,870 8.00 % 114,141 8.62 % N/A N/A WaterStone Bank 389,602 29.50 % 105,641 8.00 % 113,895 8.62 % 132,052 10.00 % Tier I capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 410,467 31.02 % 79,402 6.00 % 87,673 6.63 % N/A N/A WaterStone Bank 373,573 28.29 % 79,231 6.00 % 87,484 6.63 % 105,641 8.00 % Common Equity Tier 1 Capital (to risk-weighted assets) Consolidated Waterstone Financial , Inc. 410,467 31.02 % 59,552 4.50 % 67,823 5.12 % N/A N/A WaterStone Bank 373,573 28.29 % 59,423 4.50 % 67,676 5.12 % 85,834 6.50 % Tier I capital (to average assets) Consolidated Waterstone Financial , Inc. 410,467 23.20 % 70,760 4.00 % N/A N/A N/A N/A WaterStone Bank 373,573 21.17 % 70,573 4.00 % N/A N/A 88,216 5.00 % State of Wisconsin (to total assets) WaterStone Bank 373,573 20.90 % 107,247 6.00 % N/A N/A N/A N/A

Stock Based Compensation (Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Stock Based Compensation [Abstract]
Estimated fair value of options granted	Assumptions are used in estimating the fair value of stock options granted. The weighted average expected life of the stock options represent the period of time that the options are expected to be outstanding and is based on the historical results from the previous awards. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. The expected volatility is based on the actual volatility of a peer group including Waterstone Financial, Inc. stock from approximately five years prior to issuance date. The following assumptions were used in estimating the fair value of options granted in the years ended December 31, 2017 and 2016. 2017 2016 Minimum Maximum Minimum Maximum Dividend Yield 2.48 % 2.71 % 1.46 % 2.56 % Risk-free interest rate 1.80 % 1.93 % 1.22 % 2.04 % Expected volatility 27.79 % 32.54 % 27.17 % 31.47 % Weighted average expected life 5.3 5.5 4.5 5.5 Weighted average per share value of options $ 4.01 4.63 2.84 4.52
Stock option activity	A summary of the Company's stock option activity for the years ended December 31, 2017, 2016 and 2015 is presented below. Stock Options Shares Weighted Average Exercise Price Weighted Average Years Remaining in Contractual Term Aggregate Intrinsic Value (000's) Outstanding December 31, 2014 970,747 $ 12.33 3.32 797 Options exercisable at December 31, 2014 824,803 14.16 2.67 (829 ) Granted 1,210,000 12.79 1,584 Exercised (62,276 ) 1.90 760 Forfeited (15,424 ) 13.42 10 Outstanding December 31, 2015 2,103,047 12.90 6.15 2,533 Options exercisable at December 31, 2015 810,255 14.25 1.63 (123 ) Granted 55,000 15.54 151 Exercised (736,548 ) 15.04 2,388 Forfeited (59,000 ) 13.15 303 Outstanding December 31, 2016 1,362,499 11.83 7.74 8,785 Options exercisable at December 31, 2016 304,595 9.66 6.44 2,625 Granted 20,000 18.78 (35 ) Exercised (211,205 ) 6.48 2,233 Forfeited (12,195 ) 14.83 27 Outstanding December 31, 2017 1,159,099 12.89 7.24 4,870 Options exercisable at December 31, 2017 331,097 12.53 7.10 1,501 The following table summarizes information about the Company's stock options outstanding at December 31, 2017. Options Outstanding Weighted Average Exercise Price Remaining Life (Years) Options Exercisable Weighted Average Exercise Price Remaining Life (Years) Range of Exercise Prices $ 0.01 - $5.00 8,785 $ 1.73 4.01 8,785 $ 1.73 4.01 $ 5.01 - $10.00 - - - - - - $ 10.01 - $15.00 1,115,314 12.82 7.21 319,312 12.82 7.17 Over $15.01 35,000 18.59 9.07 3,000 18.61 9.08 1,159,099 $ 12.89 7.24 331,097 $ 12.53 7.10
Summary of nonvested stock option activity	The following table summarizes information about the Company's nonvested stock option activity for the years ended December 31, 2017 and 2016: Stock Options Shares Weighted Average Grant Date Fair Value Nonvested at December 31, 2015 1,292,792 $ 3.09 Granted 55,000 3.46 Vested (230,888 ) 2.86 Forfeited (59,000 ) 3.19 Nonvested at December 31, 2016 1,057,904 3.16 Nonvested at December 31, 2016 1,057,904 3.16 Granted 20,000 4.26 Vested (237,707 ) 2.87 Forfeited (12,195 ) 3.55 Nonvested at December 31, 2017 828,002 3.27
Summary of restricted stock shares activity	The following table summarizes information about the Company's restricted stock shares activity for the years ended December 31, 2017 and 2016: Restricted Stock Shares Weighted Average Grant Date Fair Value Nonvested at December 31, 2015 488,321 $ 12.03 Granted 20,000 14.84 Vested (109,559 ) 11.17 Forfeited (20,000 ) 12.75 Nonvested at December 31, 2016 378,762 12.39 Nonvested at December 31, 2016 378,762 12.39 Granted - - Vested (119,562 ) 11.39 Forfeited - - Nonvested at December 31, 2017 259,200 12.85

Employee Stock Ownership Plan (

Employee Stock Ownership Plan (Tables)	12 Months Ended
	Dec. 31, 2017
Employee Stock Ownership Plan [Abstract]
Employee Stock Ownership Plan	The aggregate activity in the number of unearned ESOP shares, considering the allocation of those shares committed to be released as of December 31, 2017 and 2016 is as follows: 2017 2016 Beginning ESOP shares 1,791,427 1,896,805 Shares committed to be released (105,378 ) (105,378 ) Unreleased shares 1,686,049 1,791,427 Fair value of unreleased shares (in millions) $ 28.7 33.0

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Provision (benefit) for income taxes	The provision for income taxes for the year ended December 31, 2017, 2016 and 2015 consists of the following: Years ended December 31, 2017 2016 2015 (In Thousands) Current: Federal $ 13,028 12,255 8,061 State 2,362 2,643 1,342 15,390 14,898 9,403 Deferred: Federal 2,960 1,084 (447 ) State 119 480 293 3,079 1,564 (154 ) Total $ 18,469 16,462 9,249
Differential income tax provisions computed at the Federal statutory corporate tax rate	The income tax provisions differ from that computed at the Federal statutory corporate tax rate for the years ended December 31, 2017, 2016 and 2015 as follows: Years ended December 31, 2017 2016 2015 (Dollars In Thousands) Income before income taxes $ 44,433 41,994 25,819 Tax at Federal statutory rate (35%) 15,552 14,698 9,037 Add (deduct) effect of: State income taxes net of Federal income tax benefit 1,613 2,030 1,063 Cash surrender value of life insurance (632 ) (619 ) (496 ) Non-deductible ESOP and stock option expense 380 268 181 Tax-exempt interest income (449 ) (529 ) (552 ) Non-deductible compensation 280 254 154 Stock option write off - 773 - Deferred tax asset revaluation 2,644 - - Stock compensation (1,074 ) (517 ) - Other 155 104 (138 ) Income tax provision 18,469 16,462 9,249 Effective tax rate 41.6 % 39.2 % 35.8 %
Components of net deferred tax assets (liabilities) included in prepaid expenses and other assets	The significant components of the Company's net deferred tax assets (liabilities) included in prepaid expenses and other assets are as follows at December 31, 2017 and 2016: December 31, 2017 2016 Gross deferred tax assets: (In Thousands) Fixed assets $ 480 729 Compensation agreements - 27 Restricted stock and stock options 466 638 Allowance for loan losses 3,451 6,109 Repurchase reserve for loans sold 159 183 Real estate owned 993 1,529 Nonaccrual interest 305 531 Capital loss carryforward - 21 Unrealized loss on impaired securities 23 36 Other 192 313 Total gross deferred tax assets 6,069 10,116 Gross deferred tax liabilities: Unrealized gain on securities available for sale, net (11 ) (81 ) Mortgage servicing rights (119 ) (894 ) FHLB stock (232 ) (303 ) Deferred loan fees (703 ) (820 ) Deferred liabilities (1,065 ) (2,098 ) Net deferred tax assets $ 5,004 8,018

Offsetting of Assets and Liab43

Offsetting of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Offsetting of Assets and Liabilities [Abstract]
Repurchase liabilities [Table Text Block]	The following table presents the liabilities subject to an enforceable master netting agreement as of December 31, 2017 and December 31, 2016. Gross Recognized Liabilities Gross Amounts Offset Net Amounts Presented Gross Amounts Not Offset Net Amount (In thousands) December 31, 2017 Repurchase Agreements Short-term $ 11,285 - 11,285 11,825 - Long-term - - - - - $ 11,285 - 11,285 11,825 - December 31, 2016 Repurchase Agreements Short-term $ 8,155 - 8,155 8,155 - Long-term 84,000 - 84,000 84,000 - $ 92,155 - 92,155 92,155 -

Financial Instruments with Of44

Financial Instruments with Off-Balance Sheet Risk (Tables)	12 Months Ended
	Dec. 31, 2017
Financial Instruments with Off Balance Sheet Risk [Abstract]
Financial Instruments with Off-Balance Sheet Risk	The Company is a party to financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Those instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The contract or notional amounts of those instruments reflect the extent of involvement the Company has in particular classes of financial instruments. December 31, 2017 2016 (In Thousands) Financial instruments whose contract amounts represent potential credit risk: Commitments to extend credit under first mortgage loans (1) $ 31,543 30,903 Commitments to extend credit under home equity lines of credit 14,972 14,367 Unused portion of construction loans 17,097 21,137 Unused portion of business lines of credit 16,878 15,095 Standby letters of credit 259 333 (1)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured On Recurring Basis	The following table presents information about our assets recorded in our consolidated statement of financial position at their fair value on a recurring basis as of December 31, 2017 and December 31, 2016, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. Fair Value Measurements Using December 31, 2017 Level 1 Level 2 Level 3 (In Thousands) Available for sale securities Mortgage-backed securities $ 57,435 - 57,435 - Collateralized mortgage obligations Government sponsored enterprise issued 60,500 - 60,500 - Government sponsored enterprise bonds 2,497 - 2,497 - Municipal securities 63,769 - 63,769 - Other debt securities 14,525 - 14,525 - Certificates of deposit 981 - 981 - Loans held for sale 149,896 - 149,896 - Mortgage banking derivative assets 2,004 - - 2,004 Fair Value Measurements Using December 31, 2016 Level 1 Level 2 Level 3 (In Thousands) Available for sale securities Mortgage-backed securities $ 73,413 - 73,413 - Collateralized mortgage obligations Government sponsored enterprise issued 62,002 - 62,002 - Government sponsored enterprise bonds 2,503 - 2,503 - Municipal securities 70,696 - 70,696 - Other debt securities 16,950 2,541 14,409 - Certificates of deposit 1,231 - 1,231 - Loans held for sale 225,248 - 225,248 - Mortgage banking derivative assets 3,403 - - 3,403 Mortgage banking derivative liabilities 69 - - 69
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The table below presents reconciliation for all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during 2017 and 2016. Mortgage banking derivatives, net Balance at December 31, 2015 $ 2,188 Transfer into level 3 - Mortgage derivative gain, net 1,146 Balance at December 31, 2016 3,334 Transfer into level 3 - Mortgage derivative loss, net (1,330 ) Balance at December 31, 2017 $ 2,004
Fair Value Measurements, Nonrecurring	The following table presents information about our assets recorded in our consolidated statement of financial position at their fair value on a non-recurring basis as of December 31, 2017 and December 31, 2016, and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value. Fair Value Measurements Using December 31, 2017 Level 1 Level 2 Level 3 (In Thousands) Impaired loans, net (1) $ 861 - - 861 Real estate owned 4,558 - - 4,558 Fair Value Measurements Using December 31, 2016 Level 1 Level 2 Level 3 (In Thousands) Impaired loans, net (1) $ 2,814 - - 2,814 Real estate owned 6,118 - - 6,118 _________ (1)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques	For Level 3 assets and liabilities measured at fair value on a recurring or non-recurring basis as of December 31, 2017, the significant unobservable inputs used in the fair value measurements were as follows: Fair Value at Significant Significant Unobservable Input Value December 31, 2017 Valuation Technique Unobservable Inputs Minimum Value Maximum Value Mortgage banking derivatives $ 2,004 Pricing models Pull through rate 34.4 % 99.8 % Impaired loans 861 Market approach Discount rates applied to appraisals 15.0 % 25.0 % Real estate owned 4,558 Market approach Discount rates applied to appraisals 17.3 % 85.7 % Mortgage servicing rights 1,125 Pricing models Prepayment rate 7.0 % 30.0 % Discount rate 11.0 % 12.0 % Cost to service $ 81.00 $ 204.00
Fair Value, by Balance Sheet Grouping	The carrying amounts and fair values of the Company's financial instruments consist of the following at December 31, 2017 and December 31, 2016: December 31, 2017 December 31, 2016 Carrying amount Fair Value Carrying amount Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 (In Thousands) Financial Assets Cash and cash equivalents $ 48,607 48,607 39,607 9,000 - 47,217 47,217 34,967 12,250 - Securities available-for-sale 199,707 199,707 - 199,707 - 226,795 226,795 2,541 224,254 - Loans held for sale 149,896 149,896 - 149,896 - 225,248 225,248 - 225,248 - Loans receivable 1,291,814 1,291,142 - - 1,291,142 1,177,884 1,212,967 - - 1,212,967 FHLB stock 16,875 16,875 - 16,875 - 13,275 13,275 - 13,275 - Accrued interest receivable 4,924 4,924 4,924 - - 4,281 4,281 4,281 - - Mortgage servicing rights 888 1,125 - - 1,125 2,260 3,232 - - 3,232 Mortgage banking derivative assets 2,004 2,004 - - 2,004 3,403 3,403 - - 3,403 Financial Liabilities Deposits 967,380 967,558 278,401 689,157 - 949,411 949,825 282,827 666,998 - Advance payments by borrowers for taxes 4,876 4,876 4,876 - - 4,716 4,716 4,716 - - Borrowings 386,285 384,348 - 384,348 - 387,155 390,932 - 390,932 - Accrued interest payable 886 886 886 - - 916 916 916 - - Mortgage banking derivative liabilities - - - - - 69 69 - - 69

Earnings (loss) per share (Tabl

Earnings (loss) per share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Calculations for basic and diluted earnings loss per share	Earnings per share are computed using the two-class method. Basic earnings per share is computed by dividing net income allocated to common shares by the weighted average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Participating securities include unvested restricted stock awards. Unvested restricted stock awards issued in 2012 are considered participating securities because holders of these securities have the right to receive dividends at the same rate as holders of the Company's common stock. Diluted earnings per share is computed by dividing net income by the weighted average number of common shares outstanding adjusted for the dilutive effect of all potential common shares. For the year ended December 31, 2017 2016 2015 (In Thousands, except per share amounts) Net income $ 25,964 25,532 16,570 Net income available to unvested restricted stockholders - 15 19 Net income available to common stockholders $ 25,964 25,517 16,551 Weighted average shares outstanding 27,467 27,037 29,161 Effect of dilutive potential common shares 432 337 270 Diluted weighted average shares outstanding 27,899 27,374 29,431 Basic income per share $ 0.95 0.94 0.57 Diluted income per share $ 0.93 0.93 0.56

Condensed Parent Company Only47

Condensed Parent Company Only Statements (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Parent Company Only Statements [Abstract]
Statements of Financial Condition	Statements of Financial Condition December 31, 2017 2016 (In Thousands) Assets Cash and cash equivalents $ 28,954 37,989 Securities available for sale (at fair value) - 2,541 Investment in subsidiaries 386,838 373,705 Other assets 207 170 Total Assets $ 415,999 414,405 Liabilities and shareholders' equity Liabilities: Other liabilities $ 3,895 3,715 Shareholders' equity Preferred Stock (par value $.01 per share), Authorized - 50,000,000 shares in 2017 and 2016, no shares issued - - Common stock (par value $.01 per share), Authorized - 100,000,000 shares in 2017 and in 2016, Issued - 29,501,346 in 2017 and 29,430,123 in 2016, Outstanding - 29,501,346 in 2017 and 29,430,123 in 2016 295 294 Additional paid-in-capital 326,655 322,934 Retained earnings 183,358 184,565 Unearned ESOP shares (18,991 ) (20,178 ) Cost of shares repurchased (6,030,900 in 2017 and 5,908,150 in 2016), at cost (78,736 ) (76,547 ) Accumulated other comprehensive loss (net of taxes) (477 ) (378 ) Total shareholders' equity 412,104 410,690 Total liabilities and shareholders' equity $ 415,999 414,405
Statements of Operations	Statements of Operations For the year ended December 31, 2017 2016 2015 (In Thousands) Interest income $ 675 716 770 Equity in income of subsidiaries (distributed and undistributed) 25,937 26,309 16,513 Total income 26,612 27,025 17,283 Compensation - - - Professional fees 57 34 24 Other expense 575 553 586 Total expense 632 587 610 Income before income tax expense 25,980 26,438 16,673 Income tax expense 16 906 103 Net income $ 25,964 25,532 16,570
Statements of Cash Flows	Statements of Cash Flows For the year ended December 31, 2017 2016 2015 (In Thousands) Cash flows from operating activities Net income $ 25,964 25,532 16,570 Adjustments to reconcile net income to net cash provided by operating activities: Amortization of unearned ESOP 1,956 1,633 1,385 Stock based compensation 1,902 1,913 2,817 Deferred income taxes (58 ) 854 49 Equity in earnings of subsidiaries (25,937 ) (26,309 ) (16,513 ) Change in other assets and liabilities 530 (2,031 ) (1,286 ) Net cash provided by operating activities 4,357 1,592 3,022 Net cash used in investing activities - - - Dividends received from subsidiary 14,698 12,783 4,678 Cash dividends on common stock (26,952 ) (6,917 ) (5,869 ) Financing for purchase of ESOP shares - - - Proceeds from stock option exercises 1,052 3,556 113 Proceeds/refunds from stock offering - - - Purchase of common stock returned to authorized but unissued (2,190 ) (3,858 ) (72,748 ) Net (used in) cash provided by financing activities (13,392 ) 5,564 (73,826 ) Net (decrease) increase in cash (9,035 ) 7,156 (70,804 ) Cash and cash equivalents at beginning of year 37,989 30,833 101,637 Cash and cash equivalents at end of year $ 28,954 37,989 30,833

Segment and Related Informati48

Segment and Related Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segments and Related Information [Abstract]
Schedule of segment reporting information, by segment	As of or for the Year ended December 31, 2017 Community Banking Mortgage Banking Holding Company and Other Consolidated (in thousands) Net interest income (loss) $ 50,608 (49 ) 174 50,733 Provision for loan losses (1,300 ) 134 - (1,166 ) Net interest income (loss) after provision for loan losses 51,908 (183 ) 174 51,899 Noninterest income 3,942 122,091 (1,620 ) 124,413 Noninterest expenses: Compensation, payroll taxes, and other employee benefits 17,495 80,077 (488 ) 97,084 Occupancy, office furniture, and equipment 3,127 7,051 - 10,178 FDIC insurance premiums 499 - - 499 Real estate owned 379 - - 379 Other 5,765 18,962 (988 ) 23,739 Total noninterest expenses 27,265 106,090 (1,476 ) 131,879 Income before income taxes 28,585 15,818 30 44,433 Income taxes 12,228 6,225 16 18,469 Net income $ 16,357 9,593 14 25,964 Total Assets $ 1,834,191 173,237 (201,027 ) 1,806,401 As of or for the Year ended December 31, 2016 Community Banking Mortgage Banking Holding Company and Other Consolidated (in thousands) Net interest income $ 42,940 216 288 43,444 Provision for loan losses 200 180 - 380 Net interest income after provision for loan losses 42,740 36 288 43,064 Noninterest income 4,619 122,842 (1,096 ) 126,365 Noninterest expenses: Compensation, payroll taxes, and other employee benefits 17,192 78,288 (424 ) 95,056 Occupancy, office furniture and equipment 3,165 6,182 - 9,347 FDIC insurance premiums 615 - - 615 Real estate owned 399 - - 399 Other 4,979 17,549 (510 ) 22,018 Total noninterest expenses 26,350 102,019 (934 ) 127,435 Income before income taxes 21,009 20,859 126 41,994 Income taxes 7,006 8,550 906 16,462 Net income (loss) $ 14,003 12,309 (780 ) 25,532 Total Assets $ 1,794,697 252,864 (256,942 ) 1,790,619 As of or for the Year ended December 31, 2015 Community Banking Mortgage Banking Holding Company and Other Consolidated (in thousands) Net interest income $ 37,735 759 350 38,844 Provision for loan losses 1,600 365 - 1,965 Net interest income after provision for loan losses 36,135 394 350 36,879 Noninterest income 3,493 101,499 (518 ) 104,474 Noninterest expenses: Compensation, payroll taxes, and other employee benefits 16,462 65,712 (421 ) 81,753 Occupancy, office furniture and equipment 3,278 6,009 - 9,287 FDIC insurance premiums 1,058 - - 1,058 Real estate owned 2,649 15 - 2,664 Other 4,512 16,169 91 20,772 Total noninterest expenses 27,959 87,905 (330 ) 115,534 Income before income taxes 11,669 13,988 162 25,819 Income taxes 3,419 5,727 103 9,249 Net income $ 8,250 8,261 59 16,570 Total Assets $ 1,729,582 188,324 (155,177 ) 1,762,729

Summary of Significant Accoun49

Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)Segment	Dec. 31, 2016USD ($)
Organization [Abstract]
Percentage of common shares outstanding	0.00%
Nature of Operations [Abstract]
Number of operating segments (in segments) | Segment	2
Cash and Cash Equivalents [Abstract]
Federal funds and debt instruments maturity period (in months)	3 months
Loans Held for Sale [Abstract]
Mortgage loans selling period (in days)	45 days
Carrying value of loans held for sale | $	$ 5.1	$ 6.3
Percentage of costs expensed on appropriate noninterest expense	75.50%
Income Taxes [Abstract]
Realized income tax benefit	50.00%
Office properties [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of office properties and equipment (in years)	P10Y
Office properties [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of office properties and equipment (in years)	P30Y
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of office properties and equipment (in years)	P3Y
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of office properties and equipment (in years)	P10Y
Software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of office properties and equipment (in years)	P3Y

Securities, Part I (Details)

Securities, Part I (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 199,665	$ 226,590
Gross unrealized gains	1,674	1,718
Gross unrealized losses	(1,632)	(1,513)
Securities available-for-sale	199,707	226,795
Amortized cost of investment securities by contractual maturity [Abstract]
Due within one year	10,204
Due after one year through five years	22,312
Due after five years through ten years	36,309
Due after ten years	12,176
Mortgage-related securities	118,664
Amortized cost	199,665
Fair value of investment securities by contractual maturity [Abstract]
Due within one year	10,180
Due after one year through five years	22,330
Due after five years through ten years	37,461
Due after ten years	11,801
Mortgage-related securities	117,935
Fair value	199,707
Gross gains and losses from sales of investment securities available for sale [Abstract]
Gross gains	0	0	$ 44
Gross losses	(107)	0	0
Gains on sale of investment securities, net	(107)	0	44
Proceeds from sales of investment securities	448	0	$ 1,034
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	92,678	97,458
12 months or longer	35,723	10,465
Fair value	128,401	107,923
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(574)	(889)
12 months or longer	(1,058)	(624)
Unrealized loss	(1,632)	(1,513)
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	57,351	72,858
Gross unrealized gains	324	798
Gross unrealized losses	(240)	(243)
Securities available-for-sale	57,435	73,413
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	35,136	23,433
12 months or longer	4,464	1,068
Fair value	39,600	24,501
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(143)	(222)
12 months or longer	(97)	(21)
Unrealized loss	(240)	(243)
Collateralized Mortgage Obligations, Government Sponsored Enterprise Issued [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	61,313	62,297
Gross unrealized gains	3	70
Gross unrealized losses	(816)	(365)
Securities available-for-sale	60,500	62,002
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	37,949	39,395
12 months or longer	21,651	0
Fair value	59,600	39,395
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(348)	(365)
12 months or longer	(468)	0
Unrealized loss	(816)	(365)
Mortgage-Related Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	118,664	135,155
Gross unrealized gains	327	868
Gross unrealized losses	(1,056)	(608)
Securities available-for-sale	117,935	135,415
Securities pledged as collateral to secure repurchase agreements or related to mortgage banking activities	2,500
Government-Sponsored Enterprise Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	2,500	2,500
Gross unrealized gains	0	4
Gross unrealized losses	(3)	(1)
Securities available-for-sale	2,497	2,503
Securities pledged as collateral to secure repurchase agreements or related to mortgage banking activities	0
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	2,497	2,000
12 months or longer	0	0
Fair value	2,497	2,000
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(3)	(1)
12 months or longer	0	0
Unrealized loss	(3)	(1)
Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	62,516	70,311
Gross unrealized gains	1,334	685
Gross unrealized losses	(81)	(300)
Securities available-for-sale	63,769	70,696
Securities pledged as collateral to secure repurchase agreements or related to mortgage banking activities	0
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	17,096	32,141
12 months or longer	100	0
Fair value	17,196	32,141
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(80)	(300)
12 months or longer	(1)	0
Unrealized loss	(81)	(300)
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	15,005	17,399
Gross unrealized gains	12	154
Gross unrealized losses	(492)	(603)
Securities available-for-sale	14,525	16,950
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	0	0
12 months or longer	9,508	9,397
Fair value	9,508	9,397
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	0	0
12 months or longer	(492)	(603)
Unrealized loss	(492)	(603)
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	80,021	90,210
Gross unrealized gains	1,346	843
Gross unrealized losses	(576)	(904)
Securities available-for-sale	80,791	90,149
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	980	1,225
Gross unrealized gains	1	7
Gross unrealized losses	0	(1)
Securities available-for-sale	981	1,231
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	0	489
12 months or longer	0	0
Fair value	0	489
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	0	(1)
12 months or longer	0	0
Unrealized loss	$ 0	$ (1)

Securities, Part II (Details)

Securities, Part II (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Security	Dec. 31, 2016USD ($)Security	Dec. 31, 2015USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Gain on sale	$ (107,000)	$ 0	$ 44,000
Amortized cost	199,665,000
Fair value	199,707,000
Other-than-temporary impairment charges recognized in other comprehensive loss [Roll Forward]
Credit related impairments on securities as of beginning of period	94,000	117,000
Credit-related impairments related to securities for which an other- than-temporary impairment was not previously recognized	0	0
Additional credit impairments on securities	0	(23,000)
Credit related impairments on securities as of end of period	$ 94,000	$ 94,000	$ 117,000
Securities Held to Maturity Abstract [Abstract]
Number of securities held to maturity (in securities) | Security	0	0
Securities held to maturity, at amortized cost	$ 0	$ 0
Municipal Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Number of securities that were other-than-temporarily impaired | Security	1
Amortized cost	$ 116,000
Fair value	$ 94,000
Number of securities that were in unrealized loss position twelve months or longer (in securities) | Security	1

Loans Receivable, Part I (Detai

Loans Receivable, Part I (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Mortgage Loans [Abstract]
Loans receivable	$ 1,291,814	$ 1,177,884
Percentage of total loans receivable secured by residential real estate	80.40%
Mortgage loans receivable located outside the state of Wisconsin
Percentage of total mortgage loans located outside of the state of Wisconsin
Loans receivable pledged as collateral	$ 971,300	911,900
Advances by Federal Home Loan Bank	375,000	295,000
Residential Real Estate [Member] | One- to four-family [Member]
Mortgage Loans [Abstract]
Loans receivable	439,597	392,817
Residential Real Estate [Member] | Multi Family [Member]
Mortgage Loans [Abstract]
Loans receivable	578,440	558,592
Residential Real Estate [Member] | Home Equity [Member]
Mortgage Loans [Abstract]
Loans receivable	21,124	21,778
Construction and Land [Member]
Mortgage Loans [Abstract]
Loans receivable	19,859	18,179
Commercial Real Estate [Member]
Mortgage Loans [Abstract]
Loans receivable	195,842	159,401
Consumer [Member]
Mortgage Loans [Abstract]
Loans receivable	255	319
Commercial Loans [Member]
Mortgage Loans [Abstract]
Loans receivable	$ 36,697	$ 26,798

Loans Receivable, Part II (Deta

Loans Receivable, Part II (Details) - USD ($)		Dec. 31, 2017	Dec. 31, 2016
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		$ 5,852,000	$ 8,199,000
Current	[1]	1,285,962,000	1,169,685,000
Total Loans		1,291,814,000	1,177,884,000
Loan Receivable, 1 to 59 Days Past Due, Nonaccrual Status		241,000	148,000,000,000
Loan Receivable, 60 to 89 Days Past Due, Nonaccrual Status		15,000	0
Loan Receivable, Nonaccrual Status		1,800,000	4,400,000
90 or more days past due		0	0
1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	1,562,000	2,903,000
60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	316,000	7,000
Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		3,974,000	5,289,000
Residential Real Estate [Member] | One- to four-family [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		5,156,000	7,033,000
Current	[1]	434,441,000	385,784,000
Total Loans		439,597,000	392,817,000
Residential Real Estate [Member] | One- to four-family [Member] | 1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	1,494,000	2,403,000
Residential Real Estate [Member] | One- to four-family [Member] | 60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	146,000	7,000
Residential Real Estate [Member] | One- to four-family [Member] | Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		3,516,000	4,623,000
Residential Real Estate [Member] | Multi Family [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		320,000	777,000
Current	[1]	578,120,000	557,815,000
Total Loans		578,440,000	558,592,000
Residential Real Estate [Member] | Multi Family [Member] | 1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	0	376,000
Residential Real Estate [Member] | Multi Family [Member] | 60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	128,000	0
Residential Real Estate [Member] | Multi Family [Member] | Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		192,000	401,000
Residential Real Estate [Member] | Home Equity [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		124,000	117,000
Current	[1]	21,000,000	21,661,000
Total Loans		21,124,000	21,778,000
Residential Real Estate [Member] | Home Equity [Member] | 1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	68,000	82,000
Residential Real Estate [Member] | Home Equity [Member] | 60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	0	0
Residential Real Estate [Member] | Home Equity [Member] | Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		56,000	35,000
Construction and Land [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		0	0
Current	[1]	19,859,000	18,179,000
Total Loans		19,859,000	18,179,000
Construction and Land [Member] | 1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	0	0
Construction and Land [Member] | 60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	0	0
Construction and Land [Member] | Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		0	0
Commercial Real Estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		184,000	203,000
Current	[1]	195,658,000	159,198,000
Total Loans		195,842,000	159,401,000
Commercial Real Estate [Member] | 1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	0	0
Commercial Real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	0	0
Commercial Real Estate [Member] | Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		184,000	203,000
Consumer [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		0	0
Current	[1]	255,000	319,000
Total Loans		255,000	319,000
Consumer [Member] | 1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	0	0
Consumer [Member] | 60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	0	0
Consumer [Member] | Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		0	0
Commercial Loans [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		68,000	69,000
Current	[1]	36,629,000	26,729,000
Total Loans		36,697,000	26,798,000
Commercial Loans [Member] | 1 to 59 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[2]	0	42,000
Commercial Loans [Member] | 60 to 89 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due	[3]	42,000	0
Commercial Loans [Member] | Greater than 90 Days Past Due [Member]
Financing receivable, recorded investment, aging [Abstract]
Total Past Due		$ 26,000	$ 27,000
[1]	Includes $7.9 million and $10.5 million for December 31, 2015 and 2014, respectively, which are on non-accrual status.
[2]	Includes $315,000 and $1.6 million for December 31, 2015 and 2014, respectively, which are on non-accrual status.
[3]	Includes $467,000 and $795,000 for December 31, 2015 and 2014, respectively, which are on non-accrual status.

Loans Receivable, Part III (Det

Loans Receivable, Part III (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for loan losses [Roll Forward]
Balance at beginning of period	$ 16,029	$ 16,185	$ 18,706
Provision (credit) for loan losses	(1,166)	380	1,965
Charge-offs	(1,477)	(1,607)	(6,340)
Recoveries	691	1,071	1,854
Balance at end of period	14,077	16,029	16,185
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	155	662
Allowance related to loans collectively evaluated for impairment	13,922	15,367
Loans individually evaluated for impairment	9,176	16,062
Loans collectively evaluated for impairment	1,282,638	1,161,822
Total loans	1,291,814	1,177,884
Residential Real Estate [Member] | One-to-Four Family [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period	7,164	7,763	9,877
Provision (credit) for loan losses	(299)	(407)	1,092
Charge-offs	(1,364)	(1,003)	(3,855)
Recoveries	293	811	649
Balance at end of period	5,794	7,164	7,763
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	77	499
Allowance related to loans collectively evaluated for impairment	5,717	6,665
Loans individually evaluated for impairment	7,418	10,920
Loans collectively evaluated for impairment	432,179	381,897
Total loans	439,597	392,817
Residential Real Estate [Member] | Multi Family [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period	4,809	5,000	5,358
Provision (credit) for loan losses	(494)	146	931
Charge-offs	(92)	(489)	(2,281)
Recoveries	208	152	992
Balance at end of period	4,431	4,809	5,000
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	0	0
Allowance related to loans collectively evaluated for impairment	4,431	4,809
Loans individually evaluated for impairment	1,007	3,941
Loans collectively evaluated for impairment	577,433	554,651
Total loans	578,440	558,592
Residential Real Estate [Member] | Home Equity [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period	364	433	422
Provision (credit) for loan losses	(34)	7	(27)
Charge-offs	0	(112)	(72)
Recoveries	26	36	110
Balance at end of period	356	364	433
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	44	79
Allowance related to loans collectively evaluated for impairment	312	285
Loans individually evaluated for impairment	185	442
Loans collectively evaluated for impairment	20,939	21,336
Total loans	21,124	21,778
Construction and Land [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period	1,016	904	687
Provision (credit) for loan losses	(215)	43	243
Charge-offs	(14)	(3)	(84)
Recoveries	162	72	58
Balance at end of period	949	1,016	904
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	0	0
Allowance related to loans collectively evaluated for impairment	949	1,016
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	19,859	18,179
Total loans	19,859	18,179
Commercial Real Estate [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period	1,951	1,680	1,951
Provision (credit) for loan losses	(64)	271	(266)
Charge-offs	(7)	0	(45)
Recoveries	1	0	40
Balance at end of period	1,881	1,951	1,680
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	34	83
Allowance related to loans collectively evaluated for impairment	1,847	1,868
Loans individually evaluated for impairment	540	718
Loans collectively evaluated for impairment	195,302	158,683
Total loans	195,842	159,401
Consumer [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period	12	9	8
Provision (credit) for loan losses	(3)	3	(1)
Charge-offs	0	0	(3)
Recoveries	1	0	5
Balance at end of period	10	12	9
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	0	0
Allowance related to loans collectively evaluated for impairment	10	12
Loans individually evaluated for impairment	0	0
Loans collectively evaluated for impairment	255	319
Total loans	255	319
Commercial Loans [Member]
Allowance for loan losses [Roll Forward]
Balance at beginning of period	713	396	403
Provision (credit) for loan losses	(57)	317	(7)
Charge-offs	0	0	0
Recoveries	0	0	0
Balance at end of period	656	713	$ 396
Summary of the allowance for loan loss for loans evaluated individually and collectively for impairment by collateral class [Abstract]
Allowance related to loans individually evaluated for impairment	0	1
Allowance related to loans collectively evaluated for impairment	656	712
Loans individually evaluated for impairment	26	41
Loans collectively evaluated for impairment	36,671	26,757
Total loans	$ 36,697	$ 26,798

Loans Receivable, Part IV (Deta

Loans Receivable, Part IV (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	$ 1,291,814,000	$ 1,177,884,000
Loans requiring an officers' loans committee review and approval, minimum	500,000	500,000
Minimum amount of potential loan exposure to be reviewed by credit management personnel	$ 10,000,000	$ 10,000,000
Maximum period of time loan is reviewed if renewed (in years)	1 year	1 year
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	$ 1,016,000	$ 3,476,000
Total Impaired, with no Reserve, Recorded Investment	8,160,000	12,586,000
Total Impaired, Recorded Investment	9,176,000	16,062,000
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	1,425,000	3,885,000
Total Impaired with no Reserve, Unpaid Principal Balance	10,106,000	14,929,000
Total Impaired, Unpaid Principal Balance, Total	11,531,000	18,814,000
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	155,000	662,000
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	155,000	662,000
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	409,000	409,000
Total Impaired with no Reserve, Cumulative Charge-offs	1,946,000	2,343,000
Total Impaired, Cumulative Charge-offs	2,355,000	2,752,000
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	1,039,000	3,558,000
Total Impaired with no Reserve, Average Recorded Investment	8,451,000	12,901,000
Total Impaired, Average Recorded Investment, Total	9,490,000	16,459,000
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	58,000	118,000
Total Impaired with no Reserve, Interest Paid YTD	477,000	655,000
Total Impaired, Interest Paid YTD	535,000	773,000
Residential Real Estate [Member] | One- to four-family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	439,597,000	392,817,000
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	903,000	3,007,000
Total Impaired, with no Reserve, Recorded Investment	6,515,000	7,913,000
Total Impaired, Recorded Investment	7,418,000	10,920,000
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	903,000	3,007,000
Total Impaired with no Reserve, Unpaid Principal Balance	7,604,000	9,245,000
Total Impaired, Unpaid Principal Balance, Total	8,507,000	12,252,000
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	77,000	499,000
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	77,000	499,000
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	0	0
Total Impaired with no Reserve, Cumulative Charge-offs	1,089,000	1,332,000
Total Impaired, Cumulative Charge-offs	1,089,000	1,332,000
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	913,000	3,063,000
Total Impaired with no Reserve, Average Recorded Investment	6,796,000	8,150,000
Total Impaired, Average Recorded Investment, Total	7,709,000	11,213,000
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	52,000	88,000
Total Impaired with no Reserve, Interest Paid YTD	359,000	401,000
Total Impaired, Interest Paid YTD	411,000	489,000
Residential Real Estate [Member] | Multi Family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	578,440,000	558,592,000
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	0	0
Total Impaired, with no Reserve, Recorded Investment	1,007,000	3,941,000
Total Impaired, Recorded Investment	1,007,000	3,941,000
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	0	0
Total Impaired with no Reserve, Unpaid Principal Balance	1,864,000	4,952,000
Total Impaired, Unpaid Principal Balance, Total	1,864,000	4,952,000
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	0	0
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	0	0
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	0	0
Total Impaired with no Reserve, Cumulative Charge-offs	857,000	1,011,000
Total Impaired, Cumulative Charge-offs	857,000	1,011,000
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	0	0
Total Impaired with no Reserve, Average Recorded Investment	1,005,000	4,005,000
Total Impaired, Average Recorded Investment, Total	1,005,000	4,005,000
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	0	0
Total Impaired with no Reserve, Interest Paid YTD	94,000	230,000
Total Impaired, Interest Paid YTD	94,000	230,000
Residential Real Estate [Member] | Home Equity [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	21,124,000	21,778,000
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	79,000	188,000
Total Impaired, with no Reserve, Recorded Investment	106,000	254,000
Total Impaired, Recorded Investment	185,000	442,000
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	79,000	188,000
Total Impaired with no Reserve, Unpaid Principal Balance	106,000	254,000
Total Impaired, Unpaid Principal Balance, Total	185,000	442,000
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	44,000	79,000
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	44,000	79,000
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	0	0
Total Impaired with no Reserve, Cumulative Charge-offs	0	0
Total Impaired, Cumulative Charge-offs	0	0
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	83,000	198,000
Total Impaired with no Reserve, Average Recorded Investment	111,000	258,000
Total Impaired, Average Recorded Investment, Total	194,000	456,000
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	6,000	15,000
Total Impaired with no Reserve, Interest Paid YTD	5,000	9,000
Total Impaired, Interest Paid YTD	11,000	24,000
Construction and Land [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	19,859,000	18,179,000
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	0	0
Total Impaired, with no Reserve, Recorded Investment	0	0
Total Impaired, Recorded Investment	0	0
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	0	0
Total Impaired with no Reserve, Unpaid Principal Balance	0	0
Total Impaired, Unpaid Principal Balance, Total	0	0
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	0	0
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	0	0
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	0	0
Total Impaired with no Reserve, Cumulative Charge-offs	0	0
Total Impaired, Cumulative Charge-offs	0	0
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	0	0
Total Impaired with no Reserve, Average Recorded Investment	0	0
Total Impaired, Average Recorded Investment, Total	0	0
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	0	0
Total Impaired with no Reserve, Interest Paid YTD	0	0
Total Impaired, Interest Paid YTD	0	0
Commercial Real Estate [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	195,842,000	159,401,000
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	34,000	280,000
Total Impaired, with no Reserve, Recorded Investment	506,000	438,000
Total Impaired, Recorded Investment	540,000	718,000
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	443,000	689,000
Total Impaired with no Reserve, Unpaid Principal Balance	506,000	438,000
Total Impaired, Unpaid Principal Balance, Total	949,000	1,127,000
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	34,000	83,000
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	34,000	83,000
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	409,000	409,000
Total Impaired with no Reserve, Cumulative Charge-offs	0	0
Total Impaired, Cumulative Charge-offs	409,000	409,000
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	43,000	295,000
Total Impaired with no Reserve, Average Recorded Investment	513,000	442,000
Total Impaired, Average Recorded Investment, Total	556,000	737,000
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	0	15,000
Total Impaired with no Reserve, Interest Paid YTD	19,000	13,000
Total Impaired, Interest Paid YTD	19,000	28,000
Consumer [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	255,000	319,000
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	0	0
Total Impaired, with no Reserve, Recorded Investment	0	0
Total Impaired, Recorded Investment	0	0
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	0	0
Total Impaired with no Reserve, Unpaid Principal Balance	0	0
Total Impaired, Unpaid Principal Balance, Total	0	0
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	0	0
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	0	0
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	0	0
Total Impaired with no Reserve, Cumulative Charge-offs	0	0
Total Impaired, Cumulative Charge-offs	0	0
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	0	0
Total Impaired with no Reserve, Average Recorded Investment	0	0
Total Impaired, Average Recorded Investment, Total	0	0
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	0	0
Total Impaired with no Reserve, Interest Paid YTD	0	0
Total Impaired, Interest Paid YTD	0	0
Commercial Loans [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	36,697,000	26,798,000
Impaired Loans Receivable, Recorded Investment [Abstract]
Total Impaired, with Reserve, Recorded Investment	0	1,000
Total Impaired, with no Reserve, Recorded Investment	26,000	40,000
Total Impaired, Recorded Investment	26,000	41,000
Impaired Loans Receivable, Unpaid Principal Balance [Abstract]
Total Impaired with Reserve, Unpaid Principal Balance	0	1,000
Total Impaired with no Reserve, Unpaid Principal Balance	26,000	40,000
Total Impaired, Unpaid Principal Balance, Total	26,000	41,000
Impaired Loans Receivable, Reserve [Abstract]
Total Impaired with Reserve, Reserve	0	1,000
Total Impaired with no Reserve, Reserve	0	0
Impaired Loans, Reserve	0	1,000
Impaired Loans Receivable, Cumulative Charge-Offs [Abstract]
Total Impaired with Reserve, Cumulative Charge-offs	0	0
Total Impaired with no Reserve, Cumulative Charge-offs	0	0
Total Impaired, Cumulative Charge-offs	0	0
Impaired Loans Receivable, Average Recorded Investment [Abstract]
Total Impaired with Reserve, Average Recorded Investment	0	2,000
Total Impaired with no Reserve, Average Recorded Investment	26,000	46,000
Total Impaired, Average Recorded Investment, Total	26,000	48,000
Impaired Loans Receivable, Interest Paid YTD [Abstract]
Total Impaired with Reserve, Interest Paid YTD	0	0
Total Impaired with no Reserve, Interest Paid YTD	0	2,000
Total Impaired, Interest Paid YTD	0	2,000
Substandard [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	11,563,000	15,458,000
Substandard [Member] | Residential Real Estate [Member] | One- to four-family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	7,581,000	12,845,000
Substandard [Member] | Residential Real Estate [Member] | Multi Family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	1,135,000	1,427,000
Substandard [Member] | Residential Real Estate [Member] | Home Equity [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	138,000	428,000
Substandard [Member] | Construction and Land [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	0	0
Substandard [Member] | Commercial Real Estate [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	1,124,000	717,000
Substandard [Member] | Consumer [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	0	0
Substandard [Member] | Commercial Loans [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	1,585,000	41,000
Watch [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	6,706,000	20,129,000
Watch [Member] | Residential Real Estate [Member] | One- to four-family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	4,939,000	10,509,000
Watch [Member] | Residential Real Estate [Member] | Multi Family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	330,000	3,975,000
Watch [Member] | Residential Real Estate [Member] | Home Equity [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	401,000	149,000
Watch [Member] | Construction and Land [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	0	436,000
Watch [Member] | Commercial Real Estate [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	295,000	1,389,000
Watch [Member] | Consumer [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	0	0
Watch [Member] | Commercial Loans [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	741,000	3,671,000
Pass [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	1,273,545,000	1,142,297,000
Pass [Member] | Residential Real Estate [Member] | One- to four-family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	427,077,000	369,463,000
Pass [Member] | Residential Real Estate [Member] | Multi Family [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	576,975,000	553,190,000
Pass [Member] | Residential Real Estate [Member] | Home Equity [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	20,585,000	21,201,000
Pass [Member] | Construction and Land [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	19,859,000	17,743,000
Pass [Member] | Commercial Real Estate [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	194,423,000	157,295,000
Pass [Member] | Consumer [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	255,000	319,000
Pass [Member] | Commercial Loans [Member]
Loans Receivable, Recorded Investment [Line Items]
At December 31, 2016	$ 34,371,000	$ 23,086,000

Loans Receivable, Part V (Detai

Loans Receivable, Part V (Details)	12 Months Ended
	Dec. 31, 2017USD ($)LoanPayment	Dec. 31, 2016USD ($)Loan
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring, Accruing	$ 3,077,000	$ 6,154,000
Total number of troubled debt restructurings, Accruing | Loan	4	6
Amount of troubled debt restructuring, Non-accruing	$ 2,005,000	$ 3,983,000
Total number of troubled debt restructurings, Non-accruing | Loan	11	41
Amount of troubled debt restructuring	$ 5,082,000	$ 10,137,000
Total number of troubled debt restructurings | Loan	15	47
Valuation allowance with respect to troubled debt restructurings	$ 34,000	$ 293,000,000,000
Troubled Debt Restructurings by Concession Type [Abstract]
Loans Receivable, Modifications, Loans Performing in Accordance with Modified Terms	$ 4,422,000	$ 9,376,000
Number of loans performing in accordance with modified terms (in loans) | Loan	13	45
Loans Receivable, Modifications, Loans in Default	$ 660,000	$ 761,000
Number of Loans in Default (in loans) | Loan	2	2
Loans Receivable, Modifications, Total	$ 5,082,000	$ 10,137,000
Number of Loans, Total (in loans) | Loan	15	47
Data on Troubled Debt Restructuring [Abstract]
Loans modified as a troubled debt restructure	$ 0	$ 49,000
Number of loans modified as a troubled debt restructuring (in loans) | Loan	0	1
Non-accrual Loans [Abstract]
Total non-accrual loans	$ 6,068,000	$ 9,857,000
Ratio of total non-accrual loans to total loans, net of allowance	0.47%	0.84%
Ratio of total non-accrual loans to total assets	0.34%	0.55%
Residential Real Estate [Member] | One- to four-family [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring, Accruing	$ 2,740,000	$ 3,296,000
Total number of troubled debt restructurings, Accruing | Loan	2	3
Amount of troubled debt restructuring, Non-accruing	$ 1,156,000	$ 2,399,000
Total number of troubled debt restructurings, Non-accruing | Loan	7	34
Amount of troubled debt restructuring	$ 3,896,000	$ 5,695,000
Total number of troubled debt restructurings | Loan	9	37
Data on Troubled Debt Restructuring [Abstract]
Loans modified as a troubled debt restructure	$ 0	$ 0
Number of loans modified as a troubled debt restructuring (in loans) | Loan	0	0
Non-accrual Loans [Abstract]
Total non-accrual loans	$ 4,677,000	$ 7,623,000
Residential Real Estate [Member] | Multi Family [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring, Accruing	$ 0	$ 2,514,000
Total number of troubled debt restructurings, Accruing | Loan	0	1
Amount of troubled debt restructuring, Non-accruing	$ 815,000	$ 1,427,000
Total number of troubled debt restructurings, Non-accruing | Loan	3	5
Amount of troubled debt restructuring	$ 815,000	$ 3,941,000
Total number of troubled debt restructurings | Loan	3	6
Data on Troubled Debt Restructuring [Abstract]
Loans modified as a troubled debt restructure	$ 0	$ 0
Number of loans modified as a troubled debt restructuring (in loans) | Loan	0	0
Non-accrual Loans [Abstract]
Total non-accrual loans	$ 1,007,000	$ 1,427,000
Residential Real Estate [Member] | Home Equity [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring, Accruing	$ 47,000	$ 49,000
Total number of troubled debt restructurings, Accruing | Loan	1	1
Amount of troubled debt restructuring, Non-accruing	$ 0	$ 97,000
Total number of troubled debt restructurings, Non-accruing | Loan	0	1
Amount of troubled debt restructuring	$ 47,000	$ 146,000
Total number of troubled debt restructurings | Loan	1	2
Data on Troubled Debt Restructuring [Abstract]
Loans modified as a troubled debt restructure	$ 0	$ 49,000
Number of loans modified as a troubled debt restructuring (in loans) | Loan	0	1
Non-accrual Loans [Abstract]
Total non-accrual loans	$ 107,000	$ 344,000
Construction and Land [Member]
Non-accrual Loans [Abstract]
Total non-accrual loans	0	0
Commercial Real Estate [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Amount of troubled debt restructuring, Accruing	$ 290,000	$ 295,000
Total number of troubled debt restructurings, Accruing | Loan	1	1
Amount of troubled debt restructuring, Non-accruing	$ 34,000	$ 60,000
Total number of troubled debt restructurings, Non-accruing | Loan	1	1
Amount of troubled debt restructuring	$ 324,000	$ 355,000
Total number of troubled debt restructurings | Loan	2	2
Non-accrual Loans [Abstract]
Total non-accrual loans	$ 251,000	$ 422,000
Consumer [Member]
Non-accrual Loans [Abstract]
Total non-accrual loans	0	0
Commercial Loans [Member]
Non-accrual Loans [Abstract]
Total non-accrual loans	$ 26,000	41,000
Minimum [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Period of principal forbearance, reduction in interest rate or both included in typical restructured terms (in months)	6 months
Minimum number of consecutive contractual payments received prior to consideration for a return to accrual status (in payments) | Payment
Maximum [Member]
Troubled Debt Restructuring Note, Debtor [Abstract]
Period of principal forbearance, reduction in interest rate or both included in typical restructured terms (in months)	6 months
Interest Reduction and Principal Forbearance [Member]
Troubled Debt Restructurings by Concession Type [Abstract]
Loans Receivable, Modifications, Loans Performing in Accordance with Modified Terms	$ 4,022,000	$ 8,221,000
Number of loans performing in accordance with modified terms (in loans) | Loan	9	22
Loans Receivable, Modifications, Loans in Default	$ 660,000	$ 761,000
Number of Loans in Default (in loans) | Loan	2	2
Loans Receivable, Modifications, Total	$ 4,682,000	$ 8,982,000
Number of Loans, Total (in loans) | Loan	11	24
Interest Reduction [Member]
Troubled Debt Restructurings by Concession Type [Abstract]
Loans Receivable, Modifications, Loans Performing in Accordance with Modified Terms	$ 353,000	$ 1,106,000
Number of loans performing in accordance with modified terms (in loans) | Loan	3	22
Loans Receivable, Modifications, Loans in Default	$ 0	$ 0
Number of Loans in Default (in loans) | Loan	0	0
Loans Receivable, Modifications, Total	$ 353,000	$ 1,106,000
Number of Loans, Total (in loans) | Loan	3	22
Principal Forbearance [Member]
Troubled Debt Restructurings by Concession Type [Abstract]
Loans Receivable, Modifications, Loans Performing in Accordance with Modified Terms	$ 47,000	$ 49,000
Number of loans performing in accordance with modified terms (in loans) | Loan	1	1
Loans Receivable, Modifications, Loans in Default	$ 0	$ 0
Number of Loans in Default (in loans) | Loan	0	0
Loans Receivable, Modifications, Total	$ 47,000	$ 49,000
Number of Loans, Total (in loans) | Loan	1	1

Office Properties and Equipme57

Office Properties and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Office properties and equipment [Abstract]
Office properties and equipment, gross	$ 50,840	$ 49,855
Less accumulated depreciation	(27,899)	(26,200)
Office properties and equipment, net	22,941	23,655
Depreciation of premises and equipment	2,050	2,615	$ 3,106
Rent expense totaled	4,800	4,400	$ 3,800
Minimum annual commitments under all non-cancelable lease agreements [Abstract]
Within one year	2,836
One to two years	1,831
Two to three years	1,112
Three to four years	649
Four through five years	656
After five years	1,005
Total	8,089
Land [Member]
Office properties and equipment [Abstract]
Office properties and equipment, gross	6,668	6,668
Office buildings and improvements [Member]
Office properties and equipment [Abstract]
Office properties and equipment, gross	30,587	30,319
Furniture and equipment [Member]
Office properties and equipment [Abstract]
Office properties and equipment, gross	$ 13,585	$ 12,868

Real Estate Owned (Details)

Real Estate Owned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Real Estate [Line Items]
Real estate owned	$ 4,558	$ 6,118	$ 9,190
Transferred from loans receivable	2,171	4,590
Sales	(3,213)	(7,006)
Write downs	(514)	(656)
Other Real Estate Owned	(4)	0
One- to four-family [Member]
Real Estate [Line Items]
Real estate owned	1,330	2,141
Over Four-Family [Member]
Real Estate [Line Items]
Real estate owned	0	0
Construction and land [Member]
Real Estate [Line Items]
Real estate owned	4,582	5,082
Commercial Real Estate [Member]
Real Estate [Line Items]
Real estate owned	300	300
Real Estate Owned Prior To Valuation Allowance [Member]
Real Estate [Line Items]
Real estate owned	6,212	7,523
Valuation Allowance, Real Estate Owned [Member]
Real Estate [Line Items]
Valuation allowance at end of period	$ (1,654)	$ (1,405)

Mortgage Servicing Rights (Deta

Mortgage Servicing Rights (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Mortgage servicing rights [Roll Forward]
Mortgage servicing rights, beginning balance	$ 2,260,000	$ 1,422,000
Additions	998,000	1,436,000
Amortization	(106,000)	(598,000)
Sales Of Mortgage Servicing Rights	(2,264,000)	0
Mortgage servicing rights, end of period net	888,000	2,260,000	$ 1,422,000
Valuation allowance at end of period	0	0
Mortgage servicing rights, end of period net	888,000	2,260,000	1,422,000
MSR Sales [Abstract]
Loans Originated for Sale - Residential		2,460,000,000	2,380,000,000
Sales of loans held for sale		2,530,000,000	2,320,000,000
Generated mortgage banking income			121,100,000	$ 120,000,000
Loans sold on a servicing retained basis	126,300,000	$ 318,600,000
Mortgage servicing rights sold	295,100,000		0
Mortgage servicing rights book value	2,300,000		0
Sold mortgage servicing rights	2,500,000		0
Gain on sale of MSR	178,000		$ 0
Mortgage Servicing Rights [Member]
Estimated future servicing rights amortization expense by period [Abstract]
2,017	132,000
2,018	121,000
2,019	111,000
2,020	101,000
2,021	90,000
Thereafter	333,000
Total	$ 888,000

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
Time deposits, greater than $250,000	$ 45,900	$ 44,500
Summary of interest expense on deposits [Abstract]
Interest-bearing demand deposits	28	19	$ 20
Money market and savings deposits	401	392	197
Time deposits	7,310	6,953	5,662
Interest expense on deposits	7,739	7,364	$ 5,879
Summary of the contractual maturities of time deposits [Abstract]
Within one year	587,316
More than one to two years	79,287
More than two to three years	17,706
More than three to four years	1,407
More than four through five years	3,263
Time deposits	$ 688,979	$ 666,584

Borrowings (Details)

Borrowings (Details) $ in Thousands	Dec. 31, 2017USD ($)Loan	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Long-term borrowings	$ 386,285	$ 387,155
Total debt	$ 386,285	$ 387,155
Weighted average rate	1.57%	2.27%
First Repurchase Agreement [Member]
Debt Instrument [Line Items]
Repurchase agreement outstanding balance	$ 11,300
Total commitment on repurchase agreements	$ 35,000
Second Repurchase Agreement [Member]
Debt Instrument [Line Items]
Percentage of carrying value of qualifying unencumbered mortgage loans	77.00%
Percentage of carrying value of qualifying home equity loans	65.00%
Percentage of carrying value of qualifying of over four-family loans	75.00%
FHLBC stock as collateral	$ 16,900	$ 13,300
Federal Home Loan Bank, Advances, Maturing 2027 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 175,000
FHLB, year of maturity	2,027
Federal Home Loan Bank, First Advance, Maturing 2027 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 50,000
FHLB, fixed rate	1.24%
FHLB, year of maturity	2,027
Number of Federal Home Loan Bank Advances (in loans) | Loan	1
Federal Home Loan Bank, Second Advance, Maturing 2027 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 50,000
FHLB, fixed rate	1.23%
FHLB, year of maturity	2,027
Number of Federal Home Loan Bank Advances (in loans) | Loan	1
Federal Home Loan Bank, Third Advance, Maturing 2027 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 25,000
FHLB, fixed rate	1.23%
FHLB, year of maturity	2,027
Number of Federal Home Loan Bank Advances (in loans) | Loan	1
Federal Home Loan Bank, Fourth Advance, Maturing 2027 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 50,000
FHLB, fixed rate	1.73%
FHLB, year of maturity	2,027
Number of Federal Home Loan Bank Advances (in loans) | Loan	1
FHLB, Chicago, Advances, Maturing 2017 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 0	$ 65,000
Weighted average rate	0.00%	3.19%
FHLB Chicago, Advances Maturing 2027 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 175,000	$ 0
Weighted average rate	1.38%	0.00%
Federal Home Loan Bank Advances, Maturing 2021 Member [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 100,000	$ 100,000
Weighted average rate	0.78%	0.78%
FHLB, year of maturity	2,021
Number of Federal Home Loan Bank Advances (in loans) | Loan	2
Federal Home Loan Bank Advances, First Advance, Maturing 2021 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 50,000
FHLB, year of maturity	2,021
Federal Home Loan Bank Advances, First Advance, Maturing 2021 [Member] | Minimum [Member]
Debt Instrument [Line Items]
FHLB, fixed rate	0.67%
Federal Home Loan Bank Advances, First Advance, Maturing 2021 [Member] | Maximum [Member]
Debt Instrument [Line Items]
FHLB, fixed rate	0.73%
Federal Home Loan Bank Advances, Second Advance, Maturing 2021 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 50,000
FHLB, fixed rate	0.85%
FHLB, year of maturity	2,021
Number of Federal Home Loan Bank Advances (in loans) | Loan	1
FHLB, Chicago, Advances, Maturing 2018 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 65,000	$ 65,000
Weighted average rate	2.97%	2.97%
FHLB, year of maturity	2,018
Number of Federal Home Loan Bank Advances (in loans) | Loan	3
FHLB, Chicago, Advances, Maturing 2018 [Member] | Minimum [Member]
Debt Instrument [Line Items]
FHLB, fixed rate	2.73%
FHLB, Chicago, Advances, Maturing 2018 [Member] | Maximum [Member]
Debt Instrument [Line Items]
FHLB, fixed rate	3.11%
Repurchase Agreements [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 0	$ 84,000
Weighted average rate	0.00%	3.96%
Repurchase Agreements [Member]
Debt Instrument [Line Items]
Short-term borrowings	$ 11,285	$ 8,155
Weighted average rate	4.32%	3.52%
FHLB Short Term Advances [Member]
Debt Instrument [Line Items]
Short-term borrowings	$ 35,000	$ 65,000
Weighted average rate	1.28%	0.61%
FHLB, year of maturity	2,018
Number of Federal Home Loan Bank Advances (in loans) | Loan	1

Regulatory Capital (Details)

Regulatory Capital (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets)	$ 426,057	$ 426,496
Tier I capital (to risk-weighted assets)	411,980	410,467
Common Equity Tier 1 Capital (to risk-weighted assets)	411,980
Tier I capital (to average assets)	$ 411,980	$ 410,467
Total capital (to risk-weighted assets) Ratio	30.75%	32.23%
Tier I capital (to risk-weighted assets) Ratio	29.74%	31.02%
Common Equity Tier 1 capital (to risk-weighted assets)	29.74%	31.02%
Tier I capital (to average assets) Ratio	22.43%	23.20%
Total capital (to risk-weighted assets), For Capital Adequacy Purposes	$ 110,829	$ 105,870
Total Capital (to risk-weighted assets) For Minimum Adequacy Capital Buffer	128,146
Tier 1 Capital (to risk-weighted assets) For Minimum Adequacy Capital Buffer	100,439
Common Equity Tier 1 Capital (to risk-weighted assets) For Minimum Adequacy Capital Buffer	79,658
Capital Required for Capital Adequacy	110,829	105,870
Tier I capital (to risk-weighted assets), For Capital Adequacy Purposes	83,122	79,402
Common Equity Tier I capital (to risk weighted assets), For Capital Adequacy Purposes	62,341	59,552
Tier I capital (to average assets), For Capital Adequacy Purposes	$ 73,481	$ 70,760
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	8.00%	8.00%
Total Capital (to risk-weighted assets) for Capital Required for Adequacy Capital Buffer Ratio	9.25%
Tier 1 Capital (to risk-weighted assets) For Capital Buffer Adequacy	7.25%
Common Equity Tier 1 Capital (to risk-weighted assets) For Capital Buffer Adequacy	5.75%
Tier I capital (to risk-weighted assets), For Capital Adequacy Ratio	6.00%	6.00%
Common Equity Tier I capital (to risk-weighted), For Capital Adequacy	4.50%	4.50%
Tier I capital (to average assets), For Capital Adequacy Ratio	4.00%	4.00%
Waterstone Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital (to risk-weighted assets)	$ 400,792	$ 389,602
Tier I capital (to risk-weighted assets)	386,715	373,573
Common Equity Tier 1 Capital (to risk-weighted assets)	386,715
Tier I capital (to average assets)	386,715	373,573
State of Wisconsin (to total assets)	$ 386,715	$ 373,573
Total capital (to risk-weighted assets) Ratio	28.93%	29.50%
Tier I capital (to risk-weighted assets) Ratio	27.92%	28.29%
Common Equity Tier 1 capital (to risk-weighted assets)	27.92%	28.29%
Tier I capital (to average assets) Ratio	21.10%	21.17%
State of Wisconsin (to total assets) Ratio	21.44%	20.90%
Total capital (to risk-weighted assets), For Capital Adequacy Purposes	$ 110,812	$ 105,641
Total Capital (to risk-weighted assets) For Minimum Adequacy Capital Buffer	128,127
Tier 1 Capital (to risk-weighted assets) For Minimum Adequacy Capital Buffer	100,424
Common Equity Tier 1 Capital (to risk-weighted assets) For Minimum Adequacy Capital Buffer	79,646
Capital Required for Capital Adequacy	110,812	105,641
Tier I capital (to risk-weighted assets), For Capital Adequacy Purposes	83,109	79,231
Common Equity Tier I capital (to risk weighted assets), For Capital Adequacy Purposes	62,332	59,423
Tier I capital (to average assets), For Capital Adequacy Purposes	73,304	70,573
State of Wisconsin (to total assets), For Capital Adequacy Purposes	$ 108,243	$ 107,247
Total capital (to risk-weighted assets), For Capital Adequacy Ratio	8.00%	8.00%
Total Capital (to risk-weighted assets) for Capital Required for Adequacy Capital Buffer Ratio	9.25%
Tier 1 Capital (to risk-weighted assets) For Capital Buffer Adequacy	7.25%
Common Equity Tier 1 Capital (to risk-weighted assets) For Capital Buffer Adequacy	5.75%
Tier I capital (to risk-weighted assets), For Capital Adequacy Ratio	6.00%	6.00%
Common Equity Tier I capital (to risk-weighted), For Capital Adequacy	4.50%	4.50%
Tier I capital (to average assets), For Capital Adequacy Ratio	4.00%	4.00%
State of Wisconsin (to total assets), For Capital Adequacy Ratio	6.00%	6.00%
Total capital (to risk-weighted assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions	$ 138,515	$ 132,052
Tier I capital (to risk-weighted assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions	110,812	105,641
Common Equity Tier I capital (to risk-weighted assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions	90,035	85,834
Tier I capital (to average assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions	$ 91,630	$ 88,216
Total capital (to risk-weighted assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%	10.00%
Tier I capital (to risk-weighted assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%	8.00%
Common Equity Tier I capital (to risk-weighted), To Be Well-Capitalized Under Prompt Corrective Action Provisions	6.50%	6.50%
Tier I capital (to average assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions Ratio	5.00%	5.00%

Stock Based Compensation (Detai

Stock Based Compensation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock option activity shares [Roll Forward]
Outstanding, beginning balance (in shares)	1,362,499	2,103,047	970,747
Options exercisable, beginning balance (in shares)	304,595	810,255	824,803
Granted (in shares)	20,000	55,000	1,210,000
Exercised (in shares)	(211,205)	(736,548)	(62,276)
Forfeited (in shares)	(12,195)	(59,000)	(15,424)
Outstanding, ending balance (in shares)	1,159,099	1,362,499	2,103,047	970,747
Options exercisable, ending balance (in shares)	331,097	304,595	810,255	824,803
Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning balance (in dollars per share)	$ 11.83	$ 12.90	$ 12.33
Outstanding, beginning balance (in dollars per share)	9.66	14.25	14.16
Granted (in dollars per share)	18.78	20,000	12.79
Exercised (in dollars per share)	6.48	15.04	1.90
Forfeited (in dollars per share)	14.83	13.15	13.42
Outstanding, beginning balance (in dollars per share)	12.89	9.66	14.25	$ 14.16
Outstanding, ending balance (in dollars per share)	$ 12.53	$ 11.83	$ 12.90	$ 12.33
Weighted Average Years Remaining in Contractual Term [Abstract]
Outstanding, Weighted Average Years Remaining in Contractual Term	7 years 2 months 26 days	7 years 8 months 26 days	6 years 1 month 24 days	3 years 3 months 25 days
Options exercisable, Weighted Average Years Remaining in Contractual Term	7 years 1 month 6 days	6 years 5 months 8 days	1 year 7 months 17 days	2 years 8 months 1 day
Aggregate Intrinsic Value [Abstract]
Outstanding, Aggregate Intrinsic Value, beginning period	$ 8,785,000	$ 2,533,000	$ 797,000
Options exercisable, Aggregate Intrinsic Value, beginning period	2,625,000	(123,000)	(829,000)
Granted, Aggregate Intrinsic Value	(35,000)	151,000	1,584,000
Exercised, Aggregate Intrinsic Value	2,233,000	2,388,000	760,000
Forfeited, Aggregate Intrinsic Value	27,000	303,000	10,000
Outstanding, Aggregate Intrinsic Value, ending period	4,870,000	8,785,000	2,533,000	$ 797,000
Options exercisable, Aggregate Intrinsic Value, ending period	$ 1,501,000	$ 2,625,000	$ (123,000)	$ (829,000)
Stock Options Outstanding [Abstract]
Options Outstanding Summary	1,159,099
Options Weighted Average Exercise Price on Stock Options	$ 12.89
Options Outstanding Remaining Life Years	7 years 2 months 26 days
Options Exercisable Range of Exercise Prices	331,097
Options Exercisable Weighted Average Exercise Price	$ 12.53
Options Exercisable Remaining Life Years	7 years 1 month 6 days
Nonvested stock option and restricted stock shares [Roll Forward]
Granted (in shares)	20,000	55,000	1,210,000
Vested (in shares)	0	0	(8,229)
Forfeited (in shares)	(12,195)	(59,000)	(15,424)
Exercised (in shares)	211,205	736,548	62,276
Forfeited (in shares)	12,195	59,000	15,424
Nonvested stock option and restricted stock weighted average grant date fair value [Roll Forward]
Share-based compensation expense	$ 638,000	$ 641,000	$ 580,000
Minimum [Member]
Schedule for assumptions for estimating the fair value of options granted [Abstract]
Dividend Yield (in hundredths)	2.48%	1.46%
Risk-free interest rate (in hundredths)	1.80%	1.22%
Expected volatility (in hundredths)	27.79%	27.17%
Weighted average expected life (in years)	5 years 3 months 18 days	4 years 6 months
Weighted average per share value of options (in dollars per share)	$ 4.01	$ 2.84
Maximum [Member]
Schedule for assumptions for estimating the fair value of options granted [Abstract]
Dividend Yield (in hundredths)	2.71%	2.56%
Risk-free interest rate (in hundredths)	1.93%	2.04%
Expected volatility (in hundredths)	32.54%	31.47%
Weighted average expected life (in years)	5 years 6 months	5 years 6 months
Weighted average per share value of options (in dollars per share)	$ 4.63	$ 4.52
2006 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years
Award grant life (in years)	10 years
1 Cent to Five Dollars Range of Exercise Prices [Member]
Stock Options Outstanding [Abstract]
Options Outstanding Summary	8,785
Options Weighted Average Exercise Price on Stock Options	$ 1.73
Options Outstanding Remaining Life Years	4 years 4 days
Options Exercisable Range of Exercise Prices	8,785
Options Exercisable Weighted Average Exercise Price	$ 1.73
Options Exercisable Remaining Life Years	4 years 4 days
501 to 1000 Range of Exercise Prices [Member]
Stock Options Outstanding [Abstract]
Options Outstanding Summary	0
Options Weighted Average Exercise Price on Stock Options	$ 0
Options Outstanding Remaining Life Years	0 years
Options Exercisable Range of Exercise Prices	0
Options Exercisable Weighted Average Exercise Price	$ 0
Options Exercisable Remaining Life Years	0 years
1001 to 1500 Range of Exercise Prices [Member]
Stock Options Outstanding [Abstract]
Options Outstanding Summary	1,115,314
Options Weighted Average Exercise Price on Stock Options	$ 12.82
Options Outstanding Remaining Life Years	7 years 2 months 16 days
Options Exercisable Range of Exercise Prices	319,312
Options Exercisable Weighted Average Exercise Price	$ 12.82
Options Exercisable Remaining Life Years	7 years 2 months 1 day
Over 1501 Range of Exercise Prices [Member]
Stock Options Outstanding [Abstract]
Options Outstanding Summary	35,000
Options Weighted Average Exercise Price on Stock Options	$ 18.59
Options Outstanding Remaining Life Years	9 years 25 days
Options Exercisable Range of Exercise Prices	3,000
Options Exercisable Weighted Average Exercise Price	$ 18.61
Options Exercisable Remaining Life Years	9 years 29 days
Stock Options [Member]
Weighted Average Exercise Price [Roll Forward]
Granted (in dollars per share)		$ 15.54
Nonvested stock option and restricted stock shares [Roll Forward]
Nonvested, beginning period (in shares)	1,057,904	1,292,792
Granted (in shares)	20,000	55,000
Vested (in shares)	(237,707)	(230,888)
Forfeited (in shares)	(12,195)	(59,000)
Nonvested, ending period (in shares)	828,002	1,057,904	1,292,792
Forfeited (in shares)	12,195	59,000
Nonvested stock option and restricted stock weighted average grant date fair value [Roll Forward]
Nonvested, beginning period (in dollars per share)	$ 3.16	$ 3.09
Granted (in dollars per share)	4.26	3.46
Vested (in dollars per share)	2.87	2.86
Forfeited (in dollars per share)	3.55	3.19
Nonvested, ending period (in dollars per share)	$ 3.27	$ 3.16	$ 3.09
Unrecognized stock based compensation expense	$ 2,200,000
Unrecognized stock based compensation expense recognize period (in months)	48 months
Restricted Stock [Member]
Nonvested stock option and restricted stock shares [Roll Forward]
Nonvested, beginning period (in shares)	378,762	488,321
Granted (in shares)	0	20,000
Vested (in shares)	(119,562)	(109,559)
Forfeited (in shares)	0	(20,000)
Nonvested, ending period (in shares)	259,200	378,762	488,321
Forfeited (in shares)	0	20,000
Nonvested stock option and restricted stock weighted average grant date fair value [Roll Forward]
Nonvested, beginning period (in dollars per share)	$ 12.39
Granted (in dollars per share)	0	$ 14.84
Vested (in dollars per share)	11.39	11.17	$ 12.03
Forfeited (in dollars per share)	0	12.75
Nonvested, ending period (in dollars per share)	$ 12.85	$ 12.39
Share-based compensation expense	$ 1,300,000	$ 1.3	$ 2.2
Unrecognized stock based compensation expense	$ 2,400,000	$ 4
Unrecognized stock based compensation expense recognize period (in months)	34 months	42 months

Employee Benefit Plans (Details

Employee Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Employee	Dec. 31, 2016USD ($)Employee	Dec. 31, 2015USD ($)Employee
Defined Benefit Plan Disclosure [Line Items]
Minimum age criteria for participation in benefit plan (in years)	18 years	18 years	18 years
Contributions to the Plans	$ 825,000	$ 759,000	$ 595,000
Number of employees under nonqualified salary continuation plan (in employees) | Employee	1	1	1
Defined Contribution Plan period under nonqualified salary continuation plan (in years)	10 years	10 years	10 years
Accrued liability	$ 0	$ 72,000	$ 228,000
Death benefit under nonqualified salary continuation plan	0	7,700,000	7,400,000
Cash surrender value of life insurance	0	4,700,000	$ 4,300,000
Expense for compensation	$ 0	$ 0
Waterstone Bank [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum age criteria for participation in benefit plan (in years)	18 years

Employee Stock Ownership Plan65

Employee Stock Ownership Plan (Details)	12 Months Ended
	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)	Dec. 31, 2005shares
Employee Stock Ownership Plan [Abstract]
Minimum employee age (in years)	P21Y
Minimum employee tenure (in months)	12 months
Minimum service hour required for employee stock option plan (in hours)		1,000
Borrowings under stock ownership plan | $	$ 23,800,000
Common stock open market purchase (in shares)				83,561
Amount of share released	one-twentieth
Tenure of shares earned (in years)	20 years
Compensation expense attributed to the ESOP | $	$ 2,000,000	$ 1,600,000	$ 1.4
Aggregate activity of unearned ESOP shares [Abstract]
Beginning ESOP shares (in shares)	1,791,427	1,896,805
Shares committed to be released (in shares)	(105,378)	(105,378)
Unreleased shares (in shares)	1,686,049	1,791,427
Fair value of unreleased shares | $	$ 28,700,000	$ 33,000,000

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current [Abstract]
Federal			$ 13,028,000	$ 12,255,000	$ 8,061,000
State			2,362,000	2,643,000	1,342,000
Current Total			15,390,000	14,898,000	9,403,000
Deferred [Abstract]
Federal			2,960,000	1,084,000	(447,000)
State			119,000	480,000	293,000
Deferred Total			3,079,000	1,564,000	(154,000)
Total			18,469,000	16,462,000	9,249,000
Differential income tax provisions computed at the Federal statutory corporate tax rate [Abstract]
Income (loss) before income tax			44,433,000	41,994,000	25,819,000
Tax at Federal statutory rate (35%)			15,552,000	14,698,000	9,037,000
Add (deduct) effect of [Abstract]
State income taxes net of Federal income tax benefit (expense)			1,613,000	2,030,000	1,063,000
Cash surrender value of life insurance			(632,000)	(619,000)	(496,000)
Non-deductible ESOP and stock option expense			380,000	268,000	181,000
Tax-exempt interest income			(449,000)	(529,000)	(552,000)
Reversal of federal valuation allowance on deferred taxes			280,000	254,000	154,000
Deferred tax write off			0	773,000	0
Deferred tax asset revaluation			2,644,000	0	0
Stock compensation expense			(1,074,000)	(517,000)	0
Other			155,000	104,000	(138,000)
Total			$ 18,469,000	$ 16,462,000	$ 9,249,000
Income Tax Disclosure [Line Items]
Federal statutory rate			35.00%	35.00%	35.00%
Effective tax rate			41.60%	39.20%	35.80%
Income tax expense (benefit)	$ 2,700,000
Gross deferred tax assets [Abstract]
Excess book depreciation	480,000		$ 480,000	$ 729,000
Compensation agreements	0		0	27,000
Restricted stock and stock options	466,000		466,000	638,000
Allowance for loan losses	3,451,000		3,451,000	6,109,000
Repurchase reserve for loans sold	159,000		159,000	183,000
Real estate owned write-downs	993,000		993,000	1,529,000
Interest recognized for tax but not books	305,000		305,000	531,000
Federal NOL carryforward	0		0	21,000
Unrealized loss on impaired securities	23,000		23,000	36,000
Other	192,000		192,000	313,000
Total gross deferred tax assets	6,069,000		6,069,000	10,116,000
Gross deferred tax liabilities [Abstract]
Unrealized gain on securities available for sale, net	(11,000)		(11,000)	(81,000)
Mortgage Servicing Rights	(119,000)		(119,000)	(894,000)
FHLB stock dividends	(232,000)		(232,000)	(303,000)
Deferred loan fees	(703,000)		(703,000)	(820,000)
Deferred liabilities	(1,065,000)		(1,065,000)	(2,098,000)
Net deferred tax assets	5,004,000		5,004,000	8,018,000
Operating Loss Carryforwards [Line Items]
Retained earnings excluding federal or state taxes	16,700,000		16,700,000
Reconciliation of the beginning and ending amount of unrecognized tax benefits [Roll Forward]
Balance at January 1		$ 0	0	0
Increases related to prior year tax positions			0	0
Increases related to current year tax positions			0	0
Decreases related to prior year tax positions			0	0
Balance at December 31	0		0	0	$ 0
Plan [Member]
Income Tax Disclosure [Line Items]
Federal statutory rate		21.00%
Federal [Member]
Operating Loss Carryforwards [Line Items]
NOL Carryforwards
Wisconsin [Member]
Operating Loss Carryforwards [Line Items]
NOL Carryforwards	$ 26,000		$ 26,000	$ 28,000
Operating Loss Carryforwards, Expiration Year

Offsetting of Assets and Liab67

Offsetting of Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Liabilities subject to netting agreement [Line Items]
Long term repurchase agreements	$ 386,285	$ 387,155
Net Amount [Member]
Schedule of Liabilities subject to netting agreement [Line Items]
Short-term Repurchase Agreements	0	0
Long term repurchase agreements	0	0
Repurchase Agreement Totals	0	0
Gross Recognized Liabilities [Member]
Schedule of Liabilities subject to netting agreement [Line Items]
Short-term Repurchase Agreements	11,285	8,155
Long term repurchase agreements	0	84,000
Repurchase Agreement Totals	11,285	92,155
Gross Amounts Offset [Member]
Schedule of Liabilities subject to netting agreement [Line Items]
Short-term Repurchase Agreements	0	0
Long term repurchase agreements	0	0
Repurchase Agreement Totals	0	0
Net Amounts Presented [Member]
Schedule of Liabilities subject to netting agreement [Line Items]
Short-term Repurchase Agreements	11,285	8,155
Long term repurchase agreements	0	84,000
Repurchase Agreement Totals	11,285	92,155
Gross Amounts Not Offset [Member]
Schedule of Liabilities subject to netting agreement [Line Items]
Short-term Repurchase Agreements	11,825	8,155
Long term repurchase agreements	0	84,000
Repurchase Agreement Totals	$ 11,825	$ 92,155

Financial Instruments with Of68

Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks liability amount	$ 259,000	$ 333,000
Probable losses	0	0
Commitments to Extend Credit Under Amortizing Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks asset amount	31,543,000	30,903,000
Commitments to Extend Credit Under Home Equity Lines of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks asset amount	14,972,000	14,367,000
Unused Portion of Construction Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks asset amount	17,097,000	21,137,000
Unused Portion of Business Lines of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks asset amount	$ 16,878,000	$ 15,095,000

Derivative Financial Instrume69

Derivative Financial Instruments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Forward Commitments to Sell Mortgage Loans [Member]
Derivative [Line Items]
Aggregate notional amount of derivatives	$ 281,900,000
Gain reported as a component of other assets	299,000
Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Aggregate notional amount of derivatives		$ 1,700,000
Gain reported as a component of other assets	$ 159,600,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale (at fair value)		$ 149,896,000	$ 225,248,000
Real Estate Owned, Fair Value Disclosure		4,600,000	6,100,000
Unrealized holding losses arising during the period [Abstract]
Ending balance		1,125,000
Loans and Leases Receivable, Impaired, Outstanding Balance		1,000,000	3,500,000
Loans and Leases Receivable, Impaired, Specific Reserve		155,000	662,000,000,000
Real Estate Owned, Change in Fair Value		514,000	656,000,000,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities		57,435,000	73,413,000
Collateralized mortgage obligations, Government sponsored enterprise issued		60,500,000	62,002,000
Government sponsored enterprise bonds		2,497,000	2,503,000
Municipal securities		63,769,000	70,696,000
Other debt securities		14,525,000	16,950,000
Certificates of deposit		981,000	1,231,000
Loans held for sale (at fair value)		149,896,000	225,248,000
Mortgage Banking Derivative Assets		2,004,000	3,403,000
Mortgage Banking Derivatives Liabilities			69,000
Impaired Loans, Fair Value Disclosure		861,000,000,000	2,800,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities		0	0
Collateralized mortgage obligations, Government sponsored enterprise issued		0	0
Government sponsored enterprise bonds		0	0
Municipal securities		0	0
Other debt securities		0	2,541,000
Certificates of deposit		0	0
Loans held for sale (at fair value)		0	0
Mortgage Banking Derivative Assets		0	0
Mortgage Banking Derivatives Liabilities			0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities		57,435,000	73,413,000
Collateralized mortgage obligations, Government sponsored enterprise issued		60,500,000	62,002,000
Government sponsored enterprise bonds		2,497,000	2,503,000
Municipal securities		63,769,000	70,696,000
Other debt securities		14,525,000	14,409,000
Certificates of deposit		981,000	1,231,000
Loans held for sale (at fair value)		149,896,000	225,248,000
Mortgage Banking Derivative Assets		0	0
Mortgage Banking Derivatives Liabilities			0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities		0	0
Collateralized mortgage obligations, Government sponsored enterprise issued		0	0
Government sponsored enterprise bonds		0	0
Municipal securities		0	0
Other debt securities		0	0
Certificates of deposit		0	0
Loans held for sale (at fair value)		0	0
Mortgage Banking Derivative Assets		2,004,000	3,403,000
Mortgage Banking Derivatives Liabilities			69,000
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans, Fair Value Disclosure	[1]	861,000	2,814,000
Real Estate Owned, Fair Value Disclosure		4,558,000	6,118,000
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans, Fair Value Disclosure	[1]	0	0
Real Estate Owned, Fair Value Disclosure		0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans, Fair Value Disclosure	[1]	0	0
Real Estate Owned, Fair Value Disclosure		0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans, Fair Value Disclosure	[1]	861,000	2,814,000
Real Estate Owned, Fair Value Disclosure		4,558,000	6,118,000
Mortgage Banking Derivatives [Member]
Assets measured on recurring basis, unobservable input reconciliation [Roll Forward]
Beginning balance		3,334,000	2,188,000
Transfer into level 3		0	0
Unrealized holding losses arising during the period [Abstract]
Mortgage derivative gain, net		(1,330,000)	1,146,000
Ending balance		2,004,000	$ 3,334,000
Impaired Loans, Net [Member]
Unrealized holding losses arising during the period [Abstract]
Ending balance		861,000
Real Estate Owned [Member]
Unrealized holding losses arising during the period [Abstract]
Ending balance		$ 4,558,000
[1]	Represents collateral-dependent impaired loans, net, which are included in loans.

Fair Value Measurements, Valuat

Fair Value Measurements, Valuation Techniques (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 1,125,000
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rates Applied to Appraisals	30.00%
Fair Value Inputs, Discount Rate	12.00%
Fair Value Inputs, Cost to Service	$ 204
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rates Applied to Appraisals	7.00%
Fair Value Inputs, Discount Rate	11.00%
Fair Value Inputs, Cost to Service	$ 81
Mortgage Banking Derivatives [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 2,004,000	$ 3,334,000	$ 2,188,000
Mortgage Banking Derivatives [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Pull Through Rate	99.80%
Mortgage Banking Derivatives [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Pull Through Rate	34.40%
Impaired Loans, Net [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 861,000
Impaired Loans, Net [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rates Applied to Appraisals	25.00%
Impaired Loans, Net [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rates Applied to Appraisals	15.00%
Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 4,558,000
Real Estate Owned [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rates Applied to Appraisals	85.70%
Real Estate Owned [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rates Applied to Appraisals	17.30%

Fair Value Measurements, by Bal

Fair Value Measurements, by Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Securities available for sale	$ 199,707	$ 226,795
Loans held for sale (at fair value)	149,896	225,248
Real estate owned	4,600	6,100
Fair Value, Inputs, Level 1 [Member]
Assets [Abstract]
Mortgage Servicing Rights Fair Value	0
Fair Value, Inputs, Level 2 [Member]
Assets [Abstract]
Mortgage Servicing Rights Fair Value	0
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Assets [Abstract]
Cash and cash equivalents	48,607	47,217
Securities available for sale	199,707	226,795
Loans held for sale (at fair value)	149,896	225,248
Loans receivable, net	1,291,814	1,177,884
FHLB stock	16,875	13,275
Accrued interest receivable	4,924	4,281
Mortgage Servicing Rights Fair Value	888	2,260
Mortgage banking derivative assets	2,004	3,403
Liabilities:
Deposits	967,380	949,411
Advance payments by borrowers for taxes	4,876	4,716
Borrowings	386,285	387,155
Accrued interest payable	886	916
Mortgage banking derivative liabilities	0	69
Estimate of Fair Value, Fair Value Disclosure [Member]
Assets [Abstract]
Cash and cash equivalents	48,607	47,217
Securities available for sale	199,707	226,795
Loans held for sale (at fair value)	149,896	225,248
Loans receivable, net	1,291,142	1,212,967
FHLB stock	16,875	13,275
Accrued interest receivable	4,924	4,281
Mortgage Servicing Rights Fair Value	1,125	3,232
Mortgage banking derivative assets	2,004	3,403
Liabilities:
Deposits	967,558	949,825
Advance payments by borrowers for taxes	4,876	4,716
Borrowings	384,348	390,932
Accrued interest payable	886	916
Mortgage banking derivative liabilities	0	69
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
Assets [Abstract]
Cash and cash equivalents	39,607	34,967
Securities available for sale	0	2,541
Loans held for sale (at fair value)	0	0
Loans receivable, net	0	0
FHLB stock	0	0
Accrued interest receivable	4,924	4,281
Mortgage Servicing Rights Fair Value		0
Mortgage banking derivative assets	0	0
Liabilities:
Deposits	278,401	282,827
Advance payments by borrowers for taxes	4,876	4,716
Borrowings	0	0
Accrued interest payable	886	916
Mortgage banking derivative liabilities	0	0
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Assets [Abstract]
Cash and cash equivalents	9,000	12,250
Securities available for sale	199,707	224,254
Loans held for sale (at fair value)	149,896	225,248
Loans receivable, net	0	0
FHLB stock	16,875	13,275
Accrued interest receivable	0	0
Mortgage Servicing Rights Fair Value		0
Mortgage banking derivative assets	0	0
Liabilities:
Deposits	689,157	666,998
Advance payments by borrowers for taxes	0	0
Borrowings	384,348	390,932
Accrued interest payable	0	0
Mortgage banking derivative liabilities	0	0
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
Assets [Abstract]
Cash and cash equivalents	0	0
Securities available for sale	0	0
Loans held for sale (at fair value)	0	0
Loans receivable, net	1,291,142	1,212,967
FHLB stock	0	0
Accrued interest receivable	0	0
Mortgage Servicing Rights Fair Value	1,125	3,232
Mortgage banking derivative assets	2,004	3,403
Liabilities:
Deposits	0	0
Advance payments by borrowers for taxes	0	0
Borrowings	0	0
Accrued interest payable	0	0
Mortgage banking derivative liabilities	$ 0	$ 69

Earnings (loss) per share (Deta

Earnings (loss) per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic and Diluted Earnings Per Share Calculations [Abstract]
Net income (loss)	$ 25,964	$ 25,532	$ 16,570
Net Income available to unvested restricted stockholders	0	15	19
Net Income (Loss) available to common stockholders	$ 25,964	$ 25,517	$ 16,551
Weighted average shares outstanding (in shares)	27,467,000	27,037,000	29,161,000
Effect of dilutive potential common shares (in shares)	432,000	337,000	270,000
Diluted weighted average shares outstanding (in shares)	27,899,000	27,374,000	29,431,000
Basic earnings per share (in dollars per share)	$ 0.95	$ 0.94	$ 0.57
Diluted earnings per share (in dollars per share)	$ 0.93	$ 0.93	$ 0.56
Nonvested Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0	0
Nonvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	16,467	32,923

Condensed Parent Company Only74

Condensed Parent Company Only Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 48,607	$ 47,217
Securities available for sale (at fair value)	199,707	226,795
Total assets	1,806,401	1,790,619	$ 1,762,729
Liabilities [Abstract]
Other liabilities	35,756	38,647
Shareholders' equity [Abstract]
Preferred Stock (par value $.01 per share) Authorized - 50,000,000 shares in 2014 and 20,000,000 in 2013, no shares issued	0	0
Common stock (par value $.01 per share) Authorized - 100,000,000 shares in 2017 and in 2016, Issued - 29,554,466 in 2017 and 29,430,123 in 2016, Outstanding - 29,554,466 in 2017 and 29,430,123 in 2016	295	294
Additional paid-in-capital	326,655	322,934
Retained earnings	183,358	184,565
Unearned ESOP shares	(18,991)	(20,178)
Treasury stock (0 in 2014 and 2,724,353 in 2013), at cost	(78,736)	(76,547)
Accumulated other comprehensive income (net of taxes)	(477)	(378)
Total shareholders' equity	412,104	410,690	391,930	$ 450,237
Total liabilities and shareholders' equity	$ 1,806,401	$ 1,790,619
Preferred stock - par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock - shares authorized (in shares)	50,000,000	50,000,000
Preferred stock - shares issued (in shares)	0	0
Common stock - par value (in dollars per share)	$ 0.01	$ 0.01
Common stock - shares authorized (in shares)	100,000,000	100,000,000
Common stock - shares issued (in shares)	29,501,346	29,430,123
Common stock - shares outstanding (in shares)	29,501,346	29,430,123
Treasury shares (in shares)	6,030,900	5,908,150
Statements of Operations [Abstract]
Interest income	$ 67,095	$ 63,736	61,963
Total income (loss)	50,733	43,444	38,844
Compensation	97,084	95,056	81,753
Professional fees	2,656	2,135	2,354
Other expense	13,751	13,158	11,701
Total expense	131,879	127,435	115,534
Income (loss) before income tax	44,433	41,994	25,819
Income tax expense	18,469	16,462	9,249
Net income (loss)	25,964	25,532	16,570
Cash flows from operating activities [Abstract]
Net income (loss)	25,964	25,532	16,570
Adjustments to reconcile net loss to net cash provided by operating activities [Abstract]
Amortization of unearned ESOP shares	1,956	1,633	1,385
Stock based compensation	1,902	1,913	2,817
Deferred income taxes	3,079	1,564	(154)
Change in other assets and liabilities	4,512	(2,908)	(1,494)
Net cash (used in) provided by operating activities	107,097	(24,062)	(12,991)
Cash flows from investing activities [Abstract]
Proceeds from Sale of Available-for-sale Securities, Debt	448	0	1,034
Net cash used in investing activities	(94,876)	(25,030)	(16,128)
Financing for cash dividends on common stock	(26,952)	(6,917)	(5,869)
Proceeds from stock option exercises	1,052	3,556	113
Purchase of common stock returned to authorized but unissued	(2,190)	(3,858)	(72,748)
Net cash provided by financing activities	(10,831)	(4,162)	(43,230)
Net increase (decrease) in cash	1,390	(53,254)	(72,349)
Cash and cash equivalents at beginning of period	47,217	100,471	172,820
Cash and cash equivalents at end of period	48,607	47,217	100,471
Parent Company [Member]
Assets
Cash and cash equivalents	28,954	37,989
Securities available for sale (at fair value)	0	2,541
Investment in subsidiaries	386,838	373,705
Other assets	207	170
Total assets	415,999	414,405
Liabilities [Abstract]
Other liabilities	3,895	3,715
Shareholders' equity [Abstract]
Preferred Stock (par value $.01 per share) Authorized - 50,000,000 shares in 2014 and 20,000,000 in 2013, no shares issued	0	0
Common stock (par value $.01 per share) Authorized - 100,000,000 shares in 2017 and in 2016, Issued - 29,554,466 in 2017 and 29,430,123 in 2016, Outstanding - 29,554,466 in 2017 and 29,430,123 in 2016	295	294
Additional paid-in-capital	326,655	322,934
Retained earnings	183,358	184,565
Unearned ESOP shares	(18,991)	(20,178)
Treasury stock (0 in 2014 and 2,724,353 in 2013), at cost	(78,736)	(76,547)
Accumulated other comprehensive income (net of taxes)	(477)	(378)
Total shareholders' equity	412,104	410,690
Total liabilities and shareholders' equity	$ 415,999	$ 414,405
Preferred stock - par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock - shares authorized (in shares)	50,000,000	50,000,000
Preferred stock - shares issued (in shares)	0	0
Common stock - par value (in dollars per share)	$ 0.01	$ 0.01
Common stock - shares authorized (in shares)	100,000,000	100,000,000
Common stock - shares issued (in shares)	29,501,346	29,430,123
Common stock - shares outstanding (in shares)	29,501,346	29,430,123
Treasury shares (in shares)	6,030,900	5,908,150
Statements of Operations [Abstract]
Interest income	$ 675	$ 716	770
Equity in loss of subsidiaries	25,937	26,309	16,513
Total income (loss)	26,612	27,025	17,283
Compensation	0	0	0
Professional fees	57	34	24
Other expense	575	553	586
Total expense	632	587	610
Income (loss) before income tax	25,980	26,438	16,673
Income tax expense	16	906	103
Net income (loss)	25,964	25,532	16,570
Cash flows from operating activities [Abstract]
Net income (loss)	25,964	25,532	16,570
Adjustments to reconcile net loss to net cash provided by operating activities [Abstract]
Amortization of unearned ESOP shares	1,956	1,633	1,385
Stock based compensation	1,902	1,913	2,817
Deferred income taxes	(58)	854	49
Equity in (earnings) loss of subsidiaries	(25,937)	(26,309)	(16,513)
Change in other assets and liabilities	530	(2,031)	(1,286)
Net cash (used in) provided by operating activities	4,357	1,592	3,022
Cash flows from investing activities [Abstract]
Net cash used in investing activities	0	0	0
Parent Dividends Received from Subsidiary	14,698	12,783	4,678
Financing for cash dividends on common stock	(26,952)	(6,917)	(5,869)
Financing for purchase of ESOP	0	0	0
Proceeds from stock option exercises	1,052	3,556	113
Proceeds of stock offering	0	0	0
Purchase of common stock returned to authorized but unissued	(2,190)	(3,858)	(72,748)
Net cash provided by financing activities	(13,392)	5,564	(73,826)
Net increase (decrease) in cash	(9,035)	7,156	(70,804)
Cash and cash equivalents at beginning of period	37,989	30,833	101,637
Cash and cash equivalents at end of period	$ 28,954	$ 37,989	$ 30,833

Segment and Related Informati75

Segment and Related Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segments and Related Information [Abstract]
Number of operating segments (in segments) | Segment	2
Segment Reporting Information [Line Items]
Net interest income	$ 50,733	$ 43,444	$ 38,844
Provision for loan losses	(1,166)	380	1,965
Net interest income after provision for loan losses	51,899	43,064	36,879
Noninterest income	124,413	126,365	104,474
Noninterest expenses [Abstract]
Compensation, payroll taxes, and other employee benefits	97,084	95,056	81,753
Occupancy, office furniture and equipment	10,178	9,347	9,287
FDIC insurance premiums	499	615	1,058
Real estate owned	379	399	2,664
Other	23,739	22,018	20,772
Total noninterest expenses	131,879	127,435	115,534
Income (loss) before income tax	44,433	41,994	25,819
Income tax expense (benefit)	18,469	16,462	9,249
Net income (loss)	25,964	25,532	16,570
Total Assets	1,806,401	1,790,619	1,762,729
Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	(49)	216	759
Provision for loan losses	134	180	365
Net interest income after provision for loan losses	(183)	36	394
Noninterest income	122,091	122,842	101,499
Noninterest expenses [Abstract]
Compensation, payroll taxes, and other employee benefits	80,077	78,288	65,712
Occupancy, office furniture and equipment	7,051	6,182	6,009
FDIC insurance premiums	0	0	0
Real estate owned	0	0	15
Other	18,962	17,549	16,169
Total noninterest expenses	106,090	102,019	87,905
Income (loss) before income tax	15,818	20,859	13,988
Income tax expense (benefit)	6,225	8,550	5,727
Net income (loss)	9,593	12,309	8,261
Total Assets	173,237	252,864	188,324
Community Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	50,608	42,940	37,735
Provision for loan losses	(1,300)	200	1,600
Net interest income after provision for loan losses	51,908	42,740	36,135
Noninterest income	3,942	4,619	3,493
Noninterest expenses [Abstract]
Compensation, payroll taxes, and other employee benefits	17,495	17,192	16,462
Occupancy, office furniture and equipment	3,127	3,165	3,278
FDIC insurance premiums	499	615	1,058
Real estate owned	379	399	2,649
Other	5,765	4,979	4,512
Total noninterest expenses	27,265	26,350	27,959
Income (loss) before income tax	28,585	21,009	11,669
Income tax expense (benefit)	12,228	7,006	3,419
Net income (loss)	16,357	14,003	8,250
Total Assets	1,834,191	1,794,697	1,729,582
Holding Company and Other [Member]
Segment Reporting Information [Line Items]
Net interest income	174	288	350
Provision for loan losses	0	0	0
Net interest income after provision for loan losses	174	288	350
Noninterest income	(1,620)	(1,096)	(518)
Noninterest expenses [Abstract]
Compensation, payroll taxes, and other employee benefits	(488)	(424)	(421)
Occupancy, office furniture and equipment	0	0	0
FDIC insurance premiums	0	0	0
Real estate owned	0	0	0
Other	(988)	(510)	91
Total noninterest expenses	(1,476)	(934)	(330)
Income (loss) before income tax	30	126	162
Income tax expense (benefit)	16	906	103
Net income (loss)	14	(780)	59
Total Assets	$ (201,027)	$ (256,942)	$ (155,177)