Northfield Bancorp, Inc. (NFBK) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 20, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Entity Registrant Name	Northfield Bancorp, Inc.
Entity Central Index Key	1,493,225
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		49,059,067
Entity Current Reporting Status	Yes
Entity Public Float			$ 725,183,737
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS:
Cash and due from banks	$ 17,446	$ 18,412
Interest-bearing deposits in other financial institutions	40,393	77,673
Total cash and cash equivalents	57,839	96,085
Trading securities	9,597	7,857
Securities available-for-sale, at estimated fair value (encumbered $4,628 at December 31, 2017, and $11,786 at December 31, 2016)	515,121	498,897
Securities held-to-maturity, (estimated fair value of $9,892 at December 31, 2017, and $10,118 at December 31, 2016) (encumbered $0 at December 31, 2017, and $2,108 at December 31, 2016)	9,931	10,148
Originated loans held-for-investment, net	2,425,275	2,144,346
Loans acquired	692,803	793,240
Purchased credit-impaired (PCI) loans held-for-investment	22,741	30,498
Loans held-for-investment, net	3,140,819	2,968,084
Allowance for loan losses	(26,160)	(24,595)
Net loans held-for-investment	3,114,659	2,943,489
Accrued interest receivable	10,713	9,714
Bank owned life insurance	150,604	148,047
Federal Home Loan Bank (FHLB) of New York stock, at cost	25,046	25,123
Premises and equipment, net	25,746	26,910
Goodwill	38,411	38,411
Other real estate owned	850	850
Other assets	32,900	44,563
Total assets	3,991,417	3,850,094
LIABILITIES:
Deposits	2,836,979	2,713,587
Securities sold under agreements to repurchase	2,000	8,000
Other borrowings	469,549	465,206
Advance payments by borrowers for taxes and insurance	14,798	12,331
Accrued expenses and other liabilities	29,214	29,774
Total liabilities	3,352,540	3,228,898
STOCKHOLDERS’ EQUITY:
Preferred stock, $0.01 par value; 25,000,000 shares authorized, none issued or outstanding	0	0
Common stock, $0.01 par value: 150,000,000 shares authorized, 60,933,707 shares issued at December 31, 2017 and 2016, 48,803,885 and 48,526,658 outstanding at December 31, 2017 and 2016, respectively	609	609
Additional paid-in-capital	548,864	547,910
Unallocated common stock held by employee stock ownership plan	(22,244)	(23,466)
Retained earnings	281,138	268,226
Accumulated other comprehensive loss	(5,451)	(4,332)
Treasury stock at cost; 12,129,822 and 12,407,049 shares at December 31, 2017 and 2016, respectively	(164,039)	(167,751)
Total stockholders’ equity	638,877	621,196
Total liabilities and stockholders’ equity	$ 3,991,417	$ 3,850,094

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Securities available-for-sale, at estimated fair value (encumbered $4,628 at December 31, 2017, and $11,786 at December 31, 2016)	$ 4,628	$ 11,786
Securities held-to-maturity, (estimated fair value of $9,892 at December 31, 2017, and $10,118 at December 31, 2016) (encumbered $0 at December 31, 2017, and $2,108 at December 31, 2016)	9,892	10,118
Held-to-maturity securities encumbered	$ 0	$ 2,108
Preferred stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (shares)	25,000,000	25,000,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	150,000,000	150,000,000
Common stock, shares issued (shares)	60,933,707	60,933,707
Common stock, shares outstanding (shares)	48,803,885	48,526,658
Treasury stock, shares (shares)	12,129,822	12,407,049

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Loans	$ 120,340	$ 111,776	$ 87,179
Mortgage-backed securities	9,174	10,832	12,982
Other securities	1,310	908	328
FHLB of New York dividends	1,461	1,171	1,149
Deposits in other financial institutions	584	285	120
Total interest income	132,869	124,972	101,758
Interest expense:
Deposits	16,386	14,287	10,423
Borrowings	7,590	7,381	9,265
Total interest expense	23,976	21,668	19,688
Net interest income	108,893	103,304	82,070
Provision for loan losses	1,411	635	353
Net interest income after provision for loan losses	107,482	102,669	81,717
Non-interest income:
Fees and service charges for customer services	4,702	4,934	3,945
Income on bank owned life insurance	5,386	3,998	3,767
Gains/(losses) on securities transactions, net	1,283	813	(339)
Other	271	327	525
Total non-interest income	11,642	10,072	7,898
Non-interest expense:
Compensation and employee benefits	38,237	39,780	29,760
Occupancy	11,270	11,411	10,039
Furniture and equipment	1,141	1,421	1,428
Data processing	4,585	6,054	3,802
Professional fees	2,774	3,461	3,037
Federal Deposit Insurance Corporation (FDIC) insurance	1,064	1,494	1,550
Other	8,307	9,325	8,493
Total non-interest expense	67,378	72,946	58,109
Income before income tax expense	51,746	39,795	31,506
Income tax expense	26,978	13,665	11,975
Net income	$ 24,768	$ 26,130	$ 19,531
Net income per common share:
Net income per common share-basic (usd per share)	$ 0.55	$ 0.59	$ 0.46
Net income per common share-diluted (usd per share)	$ 0.53	$ 0.57	$ 0.45
Basic weighted average shares outstanding (in shares)	45,325,445	44,374,389	42,285,712
Diluted weighted average shares outstanding (in shares)	46,875,730	45,717,887	43,478,481
Net income	$ 24,768	$ 26,130	$ 19,531
Unrealized losses on securities:
Net unrealized holding losses on securities	(283)	(2,202)	(3,676)
Less: reclassification adjustment for net gains included in net income (included in gains on securities transactions, net)	(169)	(306)	(57)
Net unrealized losses	(452)	(2,508)	(3,733)
Post-retirement benefits adjustment	74	244	21
Other comprehensive loss, before tax	(378)	(2,264)	(3,712)
Income tax benefit related to net unrealized holding losses on securities	113	894	1,476
Income tax expense related to reclassification adjustment for gains included in net income	68	122	23
Income tax expense related to post-retirement benefits adjustment	(30)	(98)	(8)
Other comprehensive loss, net of tax	(227)	(1,346)	(2,221)
Comprehensive income	$ 24,541	$ 24,784	$ 17,310

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Unallocated Common Stock Held by the Employee Stock Ownership Plan	Retained Earnings	Accumulated Other Comprehensive Income (loss) Net of tax	Treasury Stock
Beginning Balance at Dec. 31, 2014	$ 593,928	$ 582	$ 499,606	$ (25,782)	$ 248,908	$ (765)	$ (128,621)
Beginning Balance, shares at Dec. 31, 2014		48,402,083
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	19,531				19,531
Other comprehensive loss, net of tax	(2,221)					(2,221)
Employee Stock Ownership Plan (ESOP) shares allocated or committed to be released	2,128		1,010	1,118
Stock compensation expense	6,763		6,763
Additional tax benefit on equity awards	122		122
Net issuance of restricted stock	0		(5,190)				5,190
Net issuance of restricted stock, shares		387,280
Exercise of stock options, net	158		(771)		(85)		1,014
Exercise of stock options, shares		81,789
Cash dividends declared	(12,184)				(12,184)
Treasury stock	(48,446)						(48,446)
Treasury stock, shares		(3,305,612)
Ending Balance at Dec. 31, 2015	559,779	$ 582	501,540	(24,664)	256,170	(2,986)	(170,863)
Ending Balance, shares at Dec. 31, 2015		45,565,540
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	26,130				26,130
Other comprehensive loss, net of tax	(1,346)					(1,346)
Acquisition of Hopewell Valley Community Bank	41,721	$ 27	41,694
Acquisition of Hopewell Valley Community Bank, shares		2,707,381
Employee Stock Ownership Plan (ESOP) shares allocated or committed to be released	2,291		1,093	1,198
Stock compensation expense	7,264		7,264
Additional tax benefit on equity awards	1,512		1,512
Net issuance of restricted stock	0		(198)				198
Net issuance of restricted stock, shares		7,720
Exercise of stock options, net	$ 120		(4,995)		0		5,115
Exercise of stock options, shares	690,671	383,233
Cash dividends declared	$ (14,074)				(14,074)
Treasury stock	(2,201)						(2,201)
Treasury stock, shares		(137,216)
Ending Balance at Dec. 31, 2016	621,196	$ 609	547,910	(23,466)	268,226	(4,332)	(167,751)
Ending Balance, shares at Dec. 31, 2016		48,526,658
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle - Adoption of ASU No. 2016-09 | Cumulative effect of change in accounting principle - Adoption of ASU No. 2016-09	0		(2,898)		2,898
Net income	24,768				24,768
Other comprehensive loss, net of tax	(227)					(227)
Employee Stock Ownership Plan (ESOP) shares allocated or committed to be released	2,489		1,267	1,222
Stock compensation expense	6,197		6,197
Net forfeitures of restricted stock	0		828				(828)
Net forfeitures of restricted stock, shares		(58,447)
Exercise of stock options, net	$ 100		(4,440)				4,540
Exercise of stock options, shares	558,743	335,674
Cash dividends declared	$ (15,646)				(15,646)
Reclassification of tax effects resulting from the adoption of ASU 2018-02 | Reclassification of tax effects resulting from the adoption of ASU 2018-02	0				892	(892)
Ending Balance at Dec. 31, 2017	$ 638,877	$ 609	$ 548,864	$ (22,244)	$ 281,138	$ (5,451)	$ (164,039)
Ending Balance, shares at Dec. 31, 2017		48,803,885

Consolidated Statements Of Cha6

Consolidated Statements Of Changes In Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Dividends declared (usd per share)	$ 0.34	$ 0.31	$ 0.28
Average cost of treasury stock (usd per share)		$ 16.04	$ 14.66

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 24,768	$ 26,130	$ 19,531
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	1,411	635	353
ESOP and stock compensation expense	8,686	9,555	8,891
Depreciation	3,229	3,591	3,385
Amortization of premiums, and deferred loan costs, net of (accretion) of discounts, and deferred loan fees	2,000	2,226	1,800
Amortization of intangible assets	386	447	210
Income on bank owned life insurance	(5,386)	(3,998)	(3,767)
Gain on sale of premises and equipment and other real estate owned, net	0	0	(282)
Net gain on sale of loans held-for-sale	0	0	(4)
Proceeds from sale of loans held-for-sale	494	0	2,392
Origination of loans held-for-sale	0	0	(2,388)
(Gains) losses on securities transactions, net	(1,283)	(813)	339
Net purchases of trading securities	(626)	(637)	(687)
(Increase) decrease in accrued interest receivable	(999)	1	(248)
(Increase) decrease in other assets	(3,689)	3,052	3,359
Deferred taxes	15,193	(3,059)	(1,632)
(Decrease) increase in accrued expenses and other liabilities	(560)	571	1,059
Net cash provided by operating activities	43,624	37,701	32,311
Cash flows from investing activities:
Net increase in loans receivable	(110,177)	(87,514)	(246,562)
Purchase of loans	(64,116)	(167,345)	(186,876)
Purchase of FHLB of New York stock	(18,890)	(9,497)	(11,001)
Redemption of FHLB of New York stock	18,967	10,653	14,417
Purchases of securities available-for-sale	(137,631)	(105,860)	0
Principal payments and maturities on securities available-for-sale	114,416	162,594	173,923
Principal payments and maturities on securities held-to-maturity	200	181	870
Purchases of securities held-to-maturity	0	0	(7,657)
Proceeds from sale of securities available-for-sale	5,941	44,582	51,148
Proceeds from bank owned life insurance	2,829	0	0
Proceeds from sale of premises and equipment and other real estate owned	0	45	918
Purchases and improvements of premises and equipment	(2,065)	(932)	(802)
Net cash acquired in business combinations	0	55,479	0
Net cash used in investing activities	(190,526)	(97,614)	(211,622)
Cash flows from financing activities:
Net increase in deposits	123,392	204,455	432,264
Dividends paid	(15,646)	(14,074)	(12,184)
Exercise of stock options	100	120	158
Purchase of treasury stock	0	(2,201)	(48,446)
Additional tax benefit on equity awards	0	1,512	122
Increase in advance payments by borrowers for taxes and insurance	2,467	1,469	3,070
Repayments under capital lease obligations	(224)	(204)	(179)
Proceeds from securities sold under agreements to repurchase and other borrowings	441,570	228,978	250,314
Repayments related to securities sold under agreements to repurchase and other borrowings	(443,003)	(315,910)	(470,664)
Net cash provided by financing activities	108,656	104,145	154,455
Net (decrease) increase in cash and cash equivalents	(38,246)	44,232	(24,856)
Cash and cash equivalents at beginning of period	96,085	51,853	76,709
Cash and cash equivalents at end of period	57,839	96,085	51,853
Supplemental cash flow information:
Interest	23,765	22,037	19,738
Income taxes	12,875	14,415	10,800
Non-cash transactions:
Loans (recoveries) / charged-off, net	(154)	810	1,875
Transfers of loans to other real estate owned	0	850	0
Other real estate owned write-downs	0	0	71
Transfers of originated loans held-for-investment to held-for-sale, at fair value	494	0	0
Securities available-for-sale	0	61,633	0
Loans	0	342,566	0
Accrued interest receivable	0	1,452	0
Bank owned life insurance	0	11,269	0
Premises and equipment	0	5,926	0
Federal Home Loan Bank of New York stock	0	476	0
Goodwill and other intangible assets	0	24,265
Other assets	0	5,389	0
Total non-cash assets acquired	0	452,976	0
Deposits	0	456,203	0
Borrowings	0	2,213	0
Other liabilities	0	8,318	0
Total non-cash liabilities assumed	0	466,734	0
Net non-cash assets acquired	0	(13,758)	0
Net cash and cash equivalents acquired	0	55,479	0
Common stock issued in acquisition	$ 0	$ 41,721	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The following significant accounting and reporting policies of Northfield Bancorp, Inc. and subsidiaries (collectively, the “Company”), conform to U.S. generally accepted accounting principles (“U.S. GAAP”), and are used in preparing and presenting these consolidated financial statements. (a) Basis of Presentation The consolidated financial statements are comprised of the accounts of Northfield Bancorp, Inc. and its wholly owned subsidiaries, Northfield Investment, Inc. and Northfield Bank (the “Bank”), and the Bank’s wholly-owned significant subsidiaries, NSB Services Corp. and NSB Realty Trust. All significant intercompany accounts and transactions have been eliminated in consolidation. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheets and revenues and expenses during the reporting periods. Actual results may differ significantly from those estimates and assumptions. A material estimate that is particularly susceptible to significant change in the near term is the allowance for loan losses. In connection with the determination of this allowance, management generally obtains independent appraisals for significant properties. In addition, judgments related to the amount and timing of expected cash flows from purchased credit-impaired (“PCI”) loans, goodwill, securities valuation and impairment, and deferred income taxes, involve a higher degree of complexity and subjectivity and require estimates and assumptions about uncertain matters. Actual results may differ from the estimates and assumptions. Certain prior year amounts have been reclassified to conform to the current year presentation. (b) Business The Company, through its principal subsidiary, the Bank, provides a full range of banking services primarily to individuals and corporate customers in Richmond and Kings counties in New York, and Hunterdon, Mercer, Union and Middlesex counties in New Jersey. The Company is subject to competition from other financial institutions and to the regulations of certain federal and state agencies, and undergoes periodic examinations by those regulatory authorities. (c) Cash Equivalents Cash equivalents consist of cash on hand, due from banks, and interest-bearing deposits in other financial institutions with an original term of three months or less. (d) Securities Securities are classified at the time of purchase, based on management’s intention, as securities held-to-maturity, securities available-for-sale, or trading account securities. Securities held-to-maturity are those that management has the positive intent and ability to hold until maturity. Securities held-to-maturity are carried at amortized cost, adjusted for amortization of premiums and accretion of discounts using the level-yield method over the contractual term of the securities, adjusted for actual prepayments. Securities available-for-sale represents all securities not classified as either held-to-maturity or trading. Securities available-for-sale are carried at estimated fair value with unrealized holding gains and losses (net of related tax effects) on such securities excluded from earnings, but included as a separate component of stockholders’ equity, titled “Accumulated other comprehensive income (loss).” The cost of securities sold is determined using the specific-identification method. Security transactions are recorded on a trade-date basis. Trading securities are securities that are bought and may be held for the purpose of selling them in the near term. Trading securities are reported at estimated fair value, with unrealized holding gains and losses reported as a component of gain (loss) on securities transactions, net in non-interest income. Our evaluation of other-than-temporary impairment considers our assessments of the reason for the decline in value, the duration and severity of the impairment, our intent and ability to hold the securities (as well as the likelihood of a near-term recovery), and our intent to sell the securities and whether it is more likely than not that we will be required to sell the securities before the recovery of their amortized cost basis. If a determination is made that a debt security is other-than-temporarily impaired, the Company will estimate the amount of the unrealized loss that is attributable to credit and all other non-credit related factors. If we intend to hold securities in an unrealized loss position until the loss is recovered, which may be at maturity, the credit related component will be recognized as an other-than-temporary impairment charge in non-interest income. The non-credit related component will be recorded as an adjustment to accumulated other comprehensive income (loss), net of tax. The estimated fair value of debt securities, including mortgage-backed securities and corporate debt obligations is furnished by an independent third-party pricing service. The third-party pricing service primarily utilizes pricing models and methodologies that incorporate observable market inputs, including among other things, benchmark yields, reported trades, and projected prepayment and default rates. Management reviews the data and assumptions used in pricing the securities by its third-party provider for reasonableness. (e) Loans The accounting and reporting for PCI loans and loans classified as held-for-sale differs substantially from those loans originated and classified by the Company as held-for-investment. For purposes of reporting, discussion and analysis, management has classified its loan portfolio into four categories: (1) loans originated by the Company and held-for-sale, which are carried at the lower of aggregate cost or estimated fair value, less costs to sell, and therefore have no associated allowance for loan losses, (2) PCI loans, which are held-for-investment, and initially valued at estimated fair value on the date of acquisition, with no initial related allowance for loan losses, (3) originated loans held-for-investment, which are carried at amortized cost, less net charge-offs and the allowance for loan losses, and (4) acquired loans with no evidence of credit deterioration, which are held-for-investment, and initially valued at an estimated fair value on the date of acquisition, with no initial related allowance for loan losses. Originated and acquired net loans held-for-investment are stated at unpaid principal balance, adjusted by unamortized premiums and unearned discounts, deferred origination fees and certain direct origination costs, and the allowance for loan losses. Interest income on loans is accrued and credited to income as earned. Net loan origination fees/costs are deferred and accreted/amortized to interest income over the loan’s contractual life using the level-yield method, adjusted for actual prepayments. Generally, loans held-for-sale are designated at time of origination and generally consist of newly originated fixed rate residential loans and are recorded at the lower of aggregate cost or estimated fair value in the aggregate. Transfers of loans from held-for-investment to held-for-sale are infrequent and occur at fair value less costs to sell, with any charge-off to allowance for loan losses. Gains are recognized on a settlement-date basis and are determined by the difference between the net sales proceeds and the carrying value of the loans, including any net deferred fees or costs. Originated and acquired net loans held-for-investment are deemed impaired when it is probable, based on current information, that the Company will not collect all amounts due in accordance with the contractual terms of the loan agreement. The Company has defined the population of originated and acquired impaired loans to be all originated and acquired non-accrual loans held-for-investment with an outstanding balance of $500,000 or greater and all loans restructured in troubled debt restructurings (TDRs). Originated and acquired impaired loans held-for-investment are individually assessed to determine that the loan’s carrying value is not in excess of the expected future cash flows, discounted at the loan's original effective interest rate, or the fair value of the underlying collateral (less estimated costs to sell) if the loan is collateral dependent. Impairments, if any, are recognized through a charge to the allowance for loan losses for the amount that the loan’s carrying value exceeds the discounted cash flow analysis or estimated fair value of collateral (less estimated costs to sell) if the loan is collateral dependent. Such amounts are charged-off when considered appropriate. The allowance for loan losses is increased by the provision for loan losses charged against income and is decreased by charge-offs, net of recoveries. Loan losses are charged-off in the period the loans, or portion thereof, are deemed uncollectible. Generally, the Company will record a loan charge-off (including a partial charge-off) to reduce a loan to the estimated fair value of the underlying collateral, less cost to sell, if it is determined that it is probable that recovery will come primarily from the sale or operation of such collateral. Specific reserves on impaired loans that are not considered collateral dependent are charged-off when such amounts are not considered to be collectible. The provision for loan losses is based on management’s evaluation of the adequacy of the allowance that considers, among other things, impaired loans held-for-investment, deterioration in PCI loans subsequent to acquisition, past loan loss experience, known and inherent risks in the portfolio, and existing adverse situations that may affect borrowers’ ability to repay. Additionally, management evaluates changes, if any, in underwriting standards, collection, charge-off and recovery practices, the nature or volume of the portfolio, lending staff, concentration of loans, as well as current economic conditions, and other relevant factors. Management believes the allowance for loan losses is adequate to provide for probable and reasonably estimable incurred losses at the date of the consolidated balance sheets. The Company also maintains an allowance for estimated losses on off-balance sheet credit risks related to loan commitments and standby letters of credit. Management utilizes a methodology similar to its allowance for loan loss adequacy methodology to estimate losses on these commitments. The allowance for estimated credit losses on off-balance sheet commitments is included in other liabilities and any changes to the allowance are recorded as a component of other non-interest expense. While management uses available information to estimate probable and reasonably estimable incurred losses on loans, future additions may be necessary based on changes in conditions, including changes in economic conditions, particularly in Richmond and Kings counties in New York, and Hunterdon, Mercer, Union and Middlesex counties in New Jersey and to a lesser extent eastern Pennsylvania. Accordingly, as with most financial institutions in the market area, the ultimate collectability of a substantial portion of the Company’s loan portfolio is susceptible to changes in conditions in the Company’s marketplace. In addition, future changes in laws and regulations could make it more difficult for the Company to collect all contractual amounts due on its loans and mortgage-backed securities. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance based on their judgments about information available to them at the time of their examination. TDRs are loans where terms have been modified because of deterioration in the financial condition of the borrower. Modifications could include extension of the repayment terms of the loan, reduced interest rates, or forgiveness of accrued interest and/or principal. Once an obligation has been restructured because of such credit problems, it continues to be considered restructured until paid in full or, if the obligation yields a market rate (a rate equal to the rate the Company was willing to accept at the time of the restructuring for a new loan with comparable risk), until the year subsequent to the year in which the restructuring takes place, provided the borrower has performed under the modified terms for a six-month period. The Company records an impairment charge equal to the difference between the present value of estimated future cash flows under the restructured terms discounted at the original loan’s effective interest rate, or the underlying collateral value less costs to sell, if the loan is collateral dependent. Changes in present values attributable to the passage of time are recorded as a component of the provision for loan losses. A loan is considered past due when it is not paid in accordance with its contractual terms. The accrual of income on loans, including impaired loans held-for-investment, and other loans in the process of foreclosure, is generally discontinued when a loan becomes 90 days or more delinquent, or sooner when certain factors indicate that the ultimate collection of principal and interest is in doubt. Loans on which the accrual of income has been discontinued are designated as non-accrual loans. All previously accrued interest is reversed against interest income, and income is recognized subsequently only in the period that cash is received, provided no principal payments are due and the remaining principal balance outstanding is deemed collectible. A non-accrual loan is not returned to accrual status until both principal and interest payments are brought current and factors indicating doubtful collection no longer exist, including performance by the borrower under the loan terms for a consecutive six-month period. The Company accounts for the PCI loans based on expected cash flows. In accordance with current accounting guidance, the Company will maintain the integrity of a pool of multiple loans accounted for as a single asset and evaluate the pools for impairment, and accrual status, based on variances from the expected cash flows. (f) Federal Home Loan Bank Stock The Bank, as a member of the Federal Home Loan Bank (FHLB) of New York, is required to hold shares of capital stock in the FHLB as a condition to both becoming a member and engaging in certain transactions with the FHLB. The minimum investment requirement is determined by a “membership” investment component and an “activity-based” investment component. The membership investment component is the greater of 0.125% of the Bank’s mortgage-related assets, as defined by the FHLB, or $1,000 . The activity-based investment component is equal to 4.5% of the Bank’s outstanding advances with the FHLB. The activity-based investment component also considers other transactions, including assets originated for or sold to the FHLB, and delivery commitments issued by the FHLB. The Company currently does not enter into these other types of transactions with the FHLB. On a quarterly basis, we perform our other-than-temporary impairment analysis of FHLB stock, we evaluate, among other things, (i) its earnings performance, including the significance of any decline in net assets of the FHLB as compared to the regulatory capital amount of the FHLB, (ii) the commitment by the FHLB to continue dividend payments, and (iii) the liquidity position of the FHLB. We did not consider our investment in FHLB stock to be other-than-temporarily impaired at December 31, 2017 and 2016 . (g) Premises and Equipment, Net Premises and equipment, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Depreciation and amortization of premises and equipment, including capital leases, are computed on a straight-line basis over the estimated useful lives of the related assets. The estimated useful lives of significant classes of assets are generally as follows: buildings - forty years; furniture and equipment - five to seven years; and purchased computer software - three years. Leasehold improvements are amortized over the shorter of the term of the related lease or the estimated useful lives of the improvements. Major improvements are capitalized, while repairs and maintenance costs are charged to operations as incurred. Upon retirement or sale, any gain or loss is credited or charged to operations. (h) Bank Owned Life Insurance The Company has purchased bank owned life insurance contracts to help fund its obligations for certain employee benefit costs. The Company’s investment in such insurance contracts has been reported in the consolidated balance sheets at their cash surrender values. Changes in cash surrender values and death benefit proceeds received in excess of the related cash surrender values are recorded as non-interest income. (i) Goodwill Intangible assets resulting from acquisitions under the purchase method of accounting consist of goodwill and other intangible assets. Goodwill is not amortized and is subject to an annual assessment for impairment. The goodwill impairment analysis is generally a two-step test. However, under current accounting guidance, first we may assess qualitative factors to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. Under current accounting guidance, we are not required to calculate the fair value of a reporting unit if, based on a qualitative assessment, we determine that it was more likely than not that the unit’s fair value was not less than its carrying amount. For the year ended December 31, 2017 , we elected to perform step one of the two-step goodwill impairment test for our reporting unit. Goodwill is allocated to Northfield’s reporting unit at the date goodwill is actually recorded. If the carrying value of a reporting unit exceeds its estimated fair value, a second step in the analysis is performed to determine the amount of impairment, if any. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill. If the carrying value of a reporting unit exceeds the implied fair value of the goodwill, an impairment charge is recorded equal to the excess amount in the current period earnings. As of December 31, 2017 , the carrying value of goodwill totaled $38.4 million . The Company performed its annual goodwill impairment test, as of December 31, 2017 , and determined that the fair value of the Company’s single reporting unit to be in excess of its carrying value. The Company will test goodwill for impairment between annual test dates if an event occurs or circumstances change that would indicate the fair value of the reporting unit is below its carrying amount. No events have occurred and no circumstances have changed since the annual impairment test date that would indicate the fair value of the reporting unit is below its carrying amount. (j) Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply in the year in which those temporary differences are expected to be recovered or settled. When applicable, deferred tax assets are reduced by a valuation allowance for any portions determined not likely to be realized. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Income tax benefits are recognized and measured based upon a two-step model: 1) a tax position must be more-likely-than-not to be sustained based solely on its technical merits in order to be recognized, and 2) the benefit is measured as the largest dollar amount of that position that is more-likely-than-not to be sustained upon settlement. The difference between the benefit recognized and the tax benefit claimed on a tax return is referred to as an unrecognized tax benefit. The Company records income tax-related interest and penalties, if applicable, within income tax expense. (k) Impairment of Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted (and without interest) net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. (l) Securities Sold Under Agreements to Repurchase and Other Borrowings The Company enters into sales of securities under agreements to repurchase (Repurchase Agreements) and collateral pledge agreements (Pledge Agreements) with selected dealers and banks. Such agreements are accounted for as secured financing transactions since the Company maintains effective control over the transferred or pledged securities and the transfer meets the other accounting and recognition criteria as required by the transfer and servicing topic of the Financial Accounting Standards Board (FASB) Accounting Standards. Obligations under these agreements are reflected as a liability in the consolidated balance sheets. Securities underlying the agreements are maintained at selected dealers and banks as collateral for each transaction executed and may be sold or pledged by the counterparty. Collateral underlying Repurchase Agreements that permit the counterparty to sell or pledge the underlying collateral is disclosed on the consolidated balance sheets as “encumbered.” The Company retains the right under all Repurchase Agreements and Pledge Agreements to substitute acceptable collateral throughout the terms of the agreement. (m) Comprehensive Income (Loss) Comprehensive income (loss) includes net income and the change in unrealized holding gains and losses on securities available-for-sale, change in actuarial gains and losses on other post-retirement benefits, and change in service cost on other postretirement benefits, net of taxes. Comprehensive income (loss) and its components is presented in the Consolidated Statements of Comprehensive Income. (n) Benefits The Company sponsors a defined postretirement benefit plan that provides for medical and life insurance coverage to a limited number of retirees, as well as life insurance to all qualifying employees of the Company. The estimated cost of postretirement benefits earned is accrued during an individual’s estimated service period to the Company. The Company recognizes in its balance sheet the over-funded or under-funded status of a defined benefit postretirement plan measured as the difference between the fair value of plan assets and the benefit obligation at the end of our calendar year. The actuarial gains and losses and the prior service costs and credits that arise during the period are recognized as a component of other comprehensive income (loss), net of tax. Funds borrowed by the Employee Stock Ownership Plan (the “ESOP”) from the Company to purchase the Company’s common stock are being repaid from the Bank’s contributions over a period of up to 30 years. The Company’s common stock not yet allocated to participants is recorded as a reduction of stockholders’ equity at cost. The Company records compensation expense related to the ESOP at an amount equal to the shares committed to be released by the ESOP multiplied by the average fair value of our common stock during the reporting period. The Company recognizes the grant-date fair value of stock based awards issued to participants' as compensation cost in the consolidated statements of comprehensive income (loss). The fair value of common stock awards is based on the closing price of our common stock as reported on the NASDAQ Stock Market on the grant date. The expense related to stock options is based on the estimated fair value of the options at the date of the grant using the Black-Scholes pricing model. The awards are fixed in nature and compensation cost related to stock based awards is recognized on a straight-line basis over the requisite service periods. The Bank has a 401(k) plan covering substantially all employees. Contributions to the plan are expensed as incurred. (o) Segment Reporting As a community-focused financial institution, substantially all of the Company’s operations involve the delivery of loan and deposit products to customers. Management makes operating decisions and assesses performance based on an ongoing review of these community banking operations, which constitute the Company’s only operating segment for financial reporting purposes. (p) Net Income per Common Share Net income per common share-basic is computed by dividing the net income available to common stockholders by the weighted average number of common shares outstanding, excluding unallocated ESOP shares and unearned common stock award shares. The weighted average common shares outstanding includes the average number of shares of common stock outstanding, including shares allocated or committed to be released ESOP shares. Net income per common share-diluted is computed using the same method as basic earnings per share, but reflects the potential dilution that could occur if stock options and unvested shares of restricted stock were exercised and converted into common stock. These potentially dilutive shares are included in the weighted average number of shares outstanding for the period using the treasury stock method. In March 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, a new standard that simplifies certain aspects of accounting for share-based payments. The Company adopted ASU No. 2016-09 effective January 1, 2017. The update amended the diluted earnings per share calculation in that excess tax benefits are no longer included in assumed proceeds when determining average diluted shares outstanding under the treasury stock method. This guidance is required to be applied prospectively upon adoption. For further discussion, see - Recent Accounting Developments. When applying the treasury stock method for the year ended December 31, 2017, we added the assumed proceeds from option exercises and the average unamortized compensation costs related to unvested shares of restricted stock and stock options. We then divided this sum by our average stock price for the period to calculate assumed shares repurchased. The excess of the number of shares issuable over the number of shares assumed to be repurchased is added to basic weighted average common shares to calculate diluted earnings per share. For the years ended December 31, 2016, and 2015, we added (1) the assumed proceeds from option exercises; (2) the tax benefit, that would have been credited to additional paid-in capital assuming exercise of non-qualified stock options and vesting of shares of restricted stock; and (3) the average unamortized compensation costs related to unvested shares of restricted stock and stock options. We then divided this sum by our average stock price for the period to calculate assumed shares repurchased. The excess of the number of shares issuable over the number of shares assumed to be repurchased is added to basic weighted average common shares to calculate diluted earnings per share. At December 31, 2017 , 2016 , and 2015 , there were 1,550,285 , 1,343,498 , and 1,192,769 dilutive shares outstanding, respectively. (q) Other Real Estate Owned Assets acquired through loan foreclosure, or deed-in-lieu of, are held for sale and are initially recorded at estimated fair value less estimated selling costs when acquired, thus establishing a new cost basis. Costs after acquisition are generally expensed. If the estimated fair value of the asset subsequently declines, a write-down is recorded through other non-interest expense. (r) Recent Accounting Developments Accounting Pronouncements Adopted in 2017 In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which allows an entity to elect a reclassification from accumulated other comprehensive income (AOCI) to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The amendment states that if an entity elects to reclassify the income tax effects, the amount of that reclassification should include the effect of the change in the tax rate on the gross deferred tax amounts and related valuation allowances, in addition to other income tax effects on items remaining in AOCI. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years with early adoption permitted in a period for which financial statements have not yet been issued. The Company early adopted ASU 2018-02 retrospectively to December 31, 2017, which resulted in the reclassification from AOCI to retained earnings of $892,000 , reflected in the Consolidated Statements of Changes in Stockholders' Equity. In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting , a new standard that simplifies certain aspects of accounting for share-based payments. The amendments include the following: • Excess tax benefits and deficiencies resulting from exercise or vesting of stock awards are recorded as income tax expense or benefit on the income statement. Previously, excess tax benefits and certain tax deficiencies were recorded as equity in additional paid-in capital. This update is required to be applied prospectively upon adoption. • For diluted earnings per share calculations, excess tax benefits are no longer included in assumed proceeds when determining average diluted shares outstanding under the treasury stock method, resulting in changes to average diluted shares outstanding. This update is required to be applied prospectively upon adoption. • Excess tax benefits or deficiencies are included as income tax expense as discrete items in the period in which they occur, which impact the effective tax rate in each reporting period; however, these discrete items are not included in the projected annual effective tax rate calculation. This update is required to be applied prospectively upon adoption. • Excess tax benefits are presented as cash flows from operating activities. Previously, excess tax benefits were included as a cash inflow from financing activities. This update may be applied either prospectively or retrospectively upon adoption. The Company applied this update prospectively upon adoption and prior periods have not been adjusted. • Cash paid by an employer to taxing authorities when withholding shares for tax withholding purposes is presented as cash outflows from financing activities, which is consistent with the manner in which we have presented such employee withholding taxes in the past. Accordingly, no reclassification for prior periods is required. • An accounting policy election, using a modified retrospective transition method, to account for forfeitures as they occur or estimate the number of awards expected to be forfeited. The Company elected to account for forfeitures as they occur. The Company adopted ASU No. 2016-09 effective January 1, 2017, and upon adoption recorded a cumulative effect adjustment of $2.9 million to the opening balances of retained earnings and additional paid-in-capital. Adoption of ASU No. 2016-09 also resulted in the recognition of a $2.3 million benefit within income tax expense for the year ended December 31, 2017, which resulted in a corresponding increase to net income and earnings per share. In addition, the guidance increases average diluted shares, since the Company no longer includes such excess

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combination	Business Combination On January 8, 2016 , the Company completed its acquisition of Hopewell Valley Community Bank (“Hopewell Valley”), which, after purchase accounting adjustments, added $508.5 million to total assets, $342.6 million to loans, and $456.2 million to deposits, and nine branch offices in the Hunterdon and Mercer counties of New Jersey. Total consideration paid for Hopewell Valley was $55.4 million , consisting of $13.7 million in cash and 2,707,381 shares of common stock valued at $41.7 million based upon the $15.41 per share closing price of Northfield Bancorp, Inc.'s common stock on January 8, 2016 . The transaction was accounted for under the acquisition method of accounting. Under this method of accounting, the purchase price has been allocated to the respective assets acquired and liabilities assumed based upon their estimated fair values, net of tax. The excess of consideration paid over the fair value of the net assets acquired has been recorded as goodwill. The following table summarizes the estimated fair values of the assets acquired and the liabilities assumed at the date of acquisition for Hopewell Valley (in thousands): ASSETS ACQUIRED: January 8, 2016 Cash and cash equivalents, net $ 55,479 Securities available for sale 61,633 Loans 342,566 Accrued interest receivable 1,452 Bank-owned life insurance 11,269 Premises and equipment 5,926 Federal Home Loan Bank of New York stock, at cost 476 Goodwill 22,252 Other intangible assets 2,013 Other assets 5,389 Total assets acquired $ 508,455 LIABILITIES ASSUMED: Deposits $ 456,203 Other borrowings 2,213 Other liabilities 8,318 Total liabilities assumed $ 466,734 Net assets acquired $ 41,721 Fair Value Measurement of Assets Assumed and Liabilities Assumed The methods used to determine the fair value of the assets acquired and liabilities assumed in the Hopewell Valley acquisition were as follows: Cash and Cash Equivalents The estimated fair values of cash and cash equivalents approximate their stated face amounts, as these financial instruments are either due on demand or have short-term maturities. Securities Available-for-Sale The estimated fair values of the investment securities classified as available-for-sale were calculated utilizing Level 1 and Level 2 inputs. Management reviewed the data and assumptions used by its third party provider in pricing the securities to ensure the highest level of significant inputs is derived from observable market data. These prices were validated against other pricing sources and broker-dealer indications. Loans The acquired loan portfolio was valued based on current guidance which defines fair value as the price that would be received to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. Level 3 inputs were utilized to value the portfolio and included the use of present value techniques employing cash flow estimates and the incorporated assumptions that marketplace participants would use in estimating fair values. In instances where reliable market information was not available, the Company used its own assumptions in an effort to determine reasonable fair value. Specifically, management utilized three separate fair value analyses which a market participant would employ in estimating the total fair value adjustment. The three separate fair valuation methodologies used were: 1) interest rate loan fair value analysis; 2) general credit fair value adjustment; and 3) specific credit fair value adjustment. To prepare the interest rate fair value analysis, loans were grouped by characteristics such as loan type, term, collateral and rate. Market rates for similar loans were obtained from various external data sources and reviewed by Company management for reasonableness. The average of these rates was used as the fair value interest rate a market participant would utilize. A present value approach was utilized to calculate the interest rate fair value adjustment. The general credit fair value adjustment was calculated using a two part general credit fair value analysis: 1) expected lifetime losses; and 2) estimated fair value adjustment for qualitative factors. The expected lifetime losses were calculated using an average of historical losses of the Company, the acquired bank and peer banks. The adjustment related to qualitative factors was impacted by general economic conditions and the risk related to lack of familiarity with the originator's underwriting process. To calculate the specific credit fair value adjustment, management reviewed the acquired loan portfolio for loans meeting the definition of an impaired loan with deteriorated credit quality. Loans meeting this definition were reviewed by comparing the contractual cash flows to expected collectible cash flows. The aggregate expected cash flows less the acquisition date fair value resulted in an accretable yield amount. The accretable yield amount will be recognized over the life of the loans on a level yield basis as an adjustment to yield. Other Intangible Assets Other intangible assets consisting of core deposit premium represents the value assigned to demand, interest checking, money market and savings accounts acquired as part of an acquisition. The core deposit premium value represents the future economic benefit, including the present value of future tax benefits, of the potential cost savings from acquiring core deposits as part of an acquisition compared to the cost of alternative funding sources. The core deposit premium is being amortized over an estimated useful life of 10 years to approximate the existing deposit relationships acquired. Deposits The fair values of deposit liabilities with no stated maturity (i.e., non-interest bearing demand accounts, interest-bearing negotiable orders of withdrawal (NOW), savings and money market accounts) are equal to the carrying amounts payable on demand. The fair values of certificates of deposit represent contractual cash flows, discounted to present value using interest rates currently offered on deposits with similar characteristics and remaining maturities. Other Borrowings Other borrowings consist of securities sold under agreements to repurchase. The carrying amounts approximate their fair values because they frequently re-price to a market rate.

Securities Available-for-Sale

Securities Available-for-Sale	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Securities Available-for-Sale	Securities Available-for-Sale The following is a comparative summary of mortgage-backed securities, debt securities and other securities available-for-sale at December 31, 2017 and 2016 (in thousands): 2017 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: Government sponsored enterprises (GSE) $ 179,320 $ 1,429 $ 2,454 $ 178,295 Real estate mortgage investment conduits (REMICs): GSE 273,501 287 6,859 266,929 Non-GSE 80 — 1 79 452,901 1,716 9,314 445,303 Debt securities: Municipal bonds 343 6 — 349 Corporate bonds 67,927 401 198 68,130 68,270 407 198 68,479 Other securities Equity investments - mutual funds 323 — — 323 Other 1,016 — — 1,016 1,339 — — 1,339 Total securities available-for-sale $ 522,510 $ 2,123 $ 9,512 $ 515,121 2016 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: GSE $ 225,047 $ 2,800 $ 3,298 $ 224,549 REMICs: GSE 230,500 259 6,466 224,293 Non-GSE 280 — 10 270 455,827 3,059 9,774 449,112 Debt securities: Municipal bonds 2,151 13 6 2,158 Corporate bonds 45,373 150 364 45,159 47,524 163 370 47,317 Other securities: Equity investments-mutual funds 1,233 — 15 1,218 Other 1,250 $ — $ — 1,250 2,483 — 15 2,468 Total securities available-for-sale $ 505,834 $ 3,222 $ 10,159 $ 498,897 The following is a summary of the expected maturity distribution of debt securities available-for-sale other than mortgage-backed securities at December 31, 2017 (in thousands): Available-for-sale Amortized cost Estimated fair value Due in one year or less $ — $ — Due after one year through five years 58,174 58,285 Due after five years through ten years 10,096 10,194 $ 68,270 $ 68,479 Expected maturities on mortgage-backed securities will differ from contractual maturities as borrowers may have the right to call or prepay obligations with or without penalties. Certain securities available-for-sale are pledged or encumbered to secure borrowings under Pledge Agreements and Repurchase Agreements and for other purposes required by law. At December 31, 2017 , and December 31, 2016 , securities available-for-sale with a carrying value of $150.5 million and $108.8 million , respectively, were pledged to secure repurchase agreements and deposits. See Note 8 for further discussion regarding securities pledged or encumbered for borrowings. For the year ended December 31, 2017 , the Company had gross proceeds of $5.9 million on sales of securities available-for-sale with gross realized gains of $173,000 and gross realized losses of $4,000 . For the year ended December 31, 2016 , the Company had gross proceeds of $44.6 million on sales of securities available-for-sale with gross realized gains of $493,000 and gross realized losses of $187,000 . For the year ended December 31, 2015 , the Company had gross proceeds of $51.1 million on sales of securities available-for-sale with gross realized gains of $60,000 and gross realized losses of $3,000 . The Company recognized net gains of $1.1 million and $507,000 , on its trading securities portfolio during the years ended December 31, 2017 , and December 31, 2016 , respectively, and net losses of $396,000 , for the year ended December 31, 2015 . The Company routinely sells securities when market pricing presents, in management’s assessment, an economic benefit that outweighs holding such security, and when smaller balance securities become cost prohibitive to carry. The Company did not recognize any other-than-temporary impairment charges in earnings during the years ended December 31, 2017 , 2016 and 2015 . Gross unrealized losses on mortgage-backed securities, debt securities and other securities available-for-sale, and the estimated fair value of the related securities, aggregated by security category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2017 and 2016 , were as follows (in thousands): December 31, 2017 Less than 12 months 12 months or more Total Unrealized Estimated Unrealized Estimated Unrealized Estimated losses fair value losses fair value losses fair value Mortgage-backed securities: Pass-through certificates: GSE $ 439 $ 48,931 $ 2,015 $ 76,113 $ 2,454 $ 125,044 REMICs: GSE 933 103,644 5,926 139,830 6,859 243,474 Non-GSE — — 1 79 1 79 Debt securities: Corporate bonds 61 11,006 137 15,084 198 26,090 Total $ 1,433 $ 163,581 $ 8,079 $ 231,106 $ 9,512 $ 394,687 December 31, 2016 Less than 12 months 12 months or more Total Unrealized Estimated Unrealized Estimated Unrealized Estimated losses fair value losses fair value losses fair value Mortgage-backed securities: Pass-through certificates: GSE $ 2,703 $ 121,878 $ 595 $ 8,402 $ 3,298 $ 130,280 REMICs: GSE 1,622 75,586 4,844 97,726 6,466 173,312 Non-GSE — — 10 270 10 270 Debt securities: Municipal bonds 6 1,679 — — 6 1,679 Corporate bonds 364 26,022 — — 364 26,022 Other securities 15 947 — — 15 947 Total $ 4,710 $ 226,112 $ 5,449 $ 106,398 $ 10,159 $ 332,510 The Company held 33 pass-through mortgage-backed securities issued or guaranteed by GSEs, 19 REMIC mortgage-backed securities issued or guaranteed by GSEs, one REMIC mortgage-backed security not issued or guaranteed by GSEs, and three corporate bonds that were in a continuous unrealized loss position of greater than twelve months at December 31, 2017 . There were 20 pass-through mortgage-backed securities issued or guaranteed by GSEs, 33 REMIC mortgage-backed securities issued or guaranteed by GSEs, and two corporate bonds that were in an unrealized loss position of less than twelve months. All securities referred to above, other than the one REMIC mortgage-backed security not issued or guaranteed by a GSE, were rated investment grade at December 31, 2017 . The declines in value relate to the general interest rate environment and are considered temporary. The securities cannot be prepaid in a manner that would result in the Company not receiving all of its amortized cost. The Company neither has an intent to sell, nor is it more likely than not that the Company will be required to sell, the securities before the recovery of their amortized cost basis or, if necessary, maturity. The fair values of our investment securities could decline in the future if the underlying performance of the collateral for the collateralized mortgage obligations or other securities deteriorates and our credit enhancement levels do not provide sufficient protections to our contractual principal and interest. As a result, there is a risk that significant other-than-temporary impairments may occur in the future given the current economic environment.

Securities Held-to-Maturity

Securities Held-to-Maturity	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Securities Held-to-Maturity	Securities Held-to-Maturity The following is a summary of mortgage-backed securities held-to-maturity at December 31, 2017 and 2016 (in thousands): 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 9,931 $ 17 $ 56 $ 9,892 Total securities held-to-maturity $ 9,931 $ 17 $ 56 $ 9,892 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 10,148 $ 29 $ 59 $ 10,118 Total securities held-to-maturity $ 10,148 $ 29 $ 59 $ 10,118 Contractual maturities for mortgage-backed securities are not presented, as expected maturities on mortgage-backed securities will differ from contractual maturities as borrowers may have the right to call or prepay obligations with or without penalties. There were no sales of held-to-maturity securities for the years ended December 31, 2017 , 2016 and 2015 . The Company did no t recognize any other-than-temporary impairment charges in earnings on securities held-to-maturity during the years ended December 31, 2017 , 2016 and 2015 . At December 31, 2017 , and December 31, 2016 , securities held-to-maturity with a carrying value of $2.8 million and $5.0 million , respectively, were pledged to secure repurchase agreements and deposits. Gross unrealized losses on mortgage-backed securities held-to-maturity, and the estimated fair value of the related securities, aggregated by security category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2017 and 2016 , were as follows (in thousands): December 31, 2017 Less than 12 months 12 months or more Total Unrealized Estimated Unrealized Estimated Unrealized Estimated losses fair value losses fair value losses fair value Mortgage-backed securities: Pass-through certificates: GSEs $ 7 $ 3,922 $ 49 $ 3,735 $ 56 $ 7,657 Total $ 7 $ 3,922 $ 49 $ 3,735 $ 56 $ 7,657 December 31, 2016 Less than 12 months Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 59 $ 7,466 Total securities held-to-maturity $ 59 $ 7,466 The Company held two pass-through mortgage-backed securities held-to-maturity, issued or guaranteed by GSEs, that were in a continuous unrealized loss position of greater than twelve months, and three pass-through mortgage-backed securities held-to-maturity, issued or guaranteed by GSEs, that were in a continuous unrealized loss position of less than twelve months at December 31, 2017. Management evaluated these securities and concluded that the declines in value relate to the general interest rate environment and are considered temporary. The securities cannot be prepaid in a manner that would result in the Company not receiving all of its amortized cost. The Company neither has an intent to sell, nor is it more likely than not that the Company will be required to sell, the securities before the recovery of their amortized cost basis or, if necessary, maturity. The fair values of our investment securities could decline in the future if the underlying performance of the collateral for the collateralized mortgage obligations or other securities deteriorates and our credit enhancement levels do not provide sufficient protections to our contractual principal and interest. As a result, there is a risk that significant other-than-temporary impairments may occur in the future given the current economic environment.

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	Loans Loans held-for-investment, net, consists of the following (in thousands): December 31, 2017 2016 Originated loans: Real estate loans: Multifamily $ 1,735,712 $ 1,506,335 Commercial mortgage 445,225 412,667 One-to-four family residential mortgage 100,942 105,968 Home equity and lines of credit 66,254 65,437 Construction and land 34,545 14,065 Total real estate loans 2,382,678 2,104,472 Commercial and industrial loans 34,828 31,906 Other loans 1,430 1,497 Deferred loan cost, net 6,339 6,471 Originated loans held-for-investment, net 2,425,275 2,144,346 PCI Loans 22,741 30,498 Loans acquired: One-to-four family residential mortgage 275,053 317,639 Multifamily 199,149 215,389 Commercial mortgage 163,962 188,001 Home equity and lines of credit 20,455 25,522 Construction and land 17,201 20,887 Total acquired real estate loans 675,820 767,438 Commercial and industrial loans 16,946 25,443 Other loans 37 359 Total loans acquired 692,803 793,240 Loans held for investment, net 3,140,819 2,968,084 Allowance for loan losses (26,160 ) (24,595 ) Net loans held-for-investment $ 3,114,659 $ 2,943,489 The Company had no loans held-for-sale at December 31, 2017 , or December 31, 2016 . PCI loans totaled $22.7 million at December 31, 2017 , as compared to $ 30.5 million at December 31, 2016 . The majority of the PCI loan balance is attributable to those loans acquired as part of an FDIC-assisted transaction. The Company accounts for PCI loans utilizing U.S. GAAP applicable to loans acquired with deteriorated credit quality. At December 31, 2017 , PCI loans consisted of approximately 27% commercial real estate loans and 50% commercial and industrial loans, with the remaining balance in residential and home equity loans. At December 31, 2016 , PCI loans consisted of approximately 30% commercial real estate loans and 48% commercial and industrial loans, with the remaining balance in residential and home equity loans. The following table sets forth information regarding the estimates of the contractually required payments, the cash flows expected to be collected, and the estimated fair value of the PCI loans acquired from Hopewell Valley at January 8, 2016 (in thousands): January 8, 2016 Contractually required principal and interest at acquisition $ 16,580 Contractual cash flows not expected to be collected (non-accretable discount) (9,929 ) Expected cash flows to be collected at acquisition 6,651 Interest component of expected cash flows (accretable discount) (845 ) Fair value of acquired loans $ 5,806 The following details the accretable yield (in thousands): For The Year Ended December 31, 2017 2016 Balance at the beginning of year $ 24,215 $ 22,853 Acquisition — 845 Accretion into interest income (5,477 ) (5,225 ) Net reclassification from non-accretable difference (1) 5,764 5,742 Balance at end of year $ 24,502 $ 24,215 _______________________ (1) Reclassifications of the non-accretable difference to the accretable yield may occur subsequent to the loan acquisition dates due to increases in expected cash flows of the loans. The Company does not have any lending programs commonly referred to as subprime lending. Subprime lending generally targets borrowers with weakened credit histories typically characterized by payment delinquencies, previous charge-offs, judgments, bankruptcies, or borrowers with questionable repayment capacity as evidenced by low credit scores or high debt-burden ratios. We provide for loan losses based on the consistent application of our documented allowance for loan loss methodology. Loan losses are charged to the allowance for loans losses and recoveries are credited to it. Additions to the allowance for loan losses are provided by charges against income based on various factors which, in our judgment, deserve current recognition in estimating incurred losses. Loan losses are charged-off in the period the loans, or portion thereof, are deemed uncollectible. Generally, the Company will record a loan charge-off (including a partial charge-off) to reduce a loan to the estimated fair value of the underlying collateral, less cost to sell, for collateral dependent loans. We regularly review the loan portfolio in order to maintain the allowance for loan losses in accordance with U.S. GAAP. At December 31, 2017 and 2016 , the allowance for loan losses related to loans held-for-investment (excluding PCI loans) consisted primarily of the following two components: (1) Specific allowances are established for impaired loans (generally defined by the Company as non-accrual loans with an outstanding balance of $ 500,000 or greater and all loans restructured in troubled debt restructurings). The amount of impairment, if any, provided for as a specific reserve determined by the deficiency, if any, between the present value of expected future cash flows discounted at the original loan’s effective interest rate or the underlying collateral value (less estimated costs to sell and discounts for quick sales,) if the loan is collateral dependent, and the carrying value of the loan. Impaired loans that have no impairment losses are not considered for general allowances described below. Generally, the Company charges down a loan to the estimated fair value of the underlying collateral, less costs to sell for collateral dependent loans and, if necessary, maintains a specific reserve in the allowance for loan losses related to cash flow dependent impaired loans where the present value of the expected future cash flows, discounted at the loan’s original contractual interest rate, is less than the carrying value of the loan unless management determines that such shortfall should be charged off. (2) General allowances are established for loan losses on a portfolio basis for loans that do not meet the definition of impaired. The portfolio is grouped into similar risk characteristics, primarily loan type, loan-to-value, if collateral dependent, and internal credit risk ratings. We apply an estimated loss rate to each loan group. The loss rates applied are based on our net loss experience (using appropriate look-back and loss emergence periods) as adjusted, if appropriate, for our qualitative assessment of factors which may not be fully captured in our historical quantitative net loss rates related to: • changes in lending policies and procedures; • changes in local, regional, national, and international economic and business conditions and developments that affect the collectability of our portfolio, including the condition of various market segments; • changes in the nature and volume of our portfolio and in the terms of our loans; • changes in the experience, ability and depth of lending management and other relevant staff; • changes in the volume and severity of past due loans, the volume of non-accrual loans, and the volume and severity of adversely classified or graded loans; • changes in the quality of our loan review system; • changes in the value of underlying collateral for collateral-dependent loans; • the existence and effect of any concentrations of credit, and changes in the level of such concentrations; and • the effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in our existing portfolio. The loss emergence period is the estimated time from the date of the loss event to the actual recognition of the loss (typically the first charge-off), and is determined based upon a study of the Company's past loss experience by loan groups. This evaluation is inherently subjective, as it requires material estimates that may be susceptible to significant revisions based upon changes in economic and real estate market conditions. Actual loan losses may be significantly more than the allowance for loan losses we have established, which could have a material negative effect on our financial results. Prior to December 31, 2016, we maintained an amount identified as the unallocated component within the allowance for loan losses related to indicators of loan losses not fully captured in other components of the allowance for loan losses methodology, as well as the inherent imprecision of the loss estimation process. During the fourth quarter of 2016, the Company enhanced the allowance for loan losses qualitative framework to more fully capture the risks related to certain loan loss factors. These enhancements are meant to increase the level of precision in the allowance for loan losses. As a result, the Company no longer has an unallocated reserve in its allowance for loan losses, as the risks and uncertainties meant to be captured by the unallocated allowance have been included in the qualitative framework for the respective loan portfolios. Held-for-investment loans acquired with no evidence of credit deterioration are initially valued at an estimated fair value on the date of acquisition, with no initial related allowance for loan losses. These loans are evaluated for impairment on a quarterly basis as part of our analysis of the allowance for loan losses. In underwriting a loan secured by real property, we require an appraisal (or an automated valuation model) of the property by an independent licensed appraiser approved by the Company’s board of directors. The appraisal is subject to review by an independent third-party hired by the Company. We review and inspect properties before disbursement of funds during the term of a construction loan. Generally, management obtains updated appraisals when a loan is deemed impaired, or sooner if management deems it appropriate. These appraisals may be more limited than those prepared for the underwriting of a new loan. In addition, when the Company acquires other real estate owned, it generally obtains a current appraisal to substantiate the net carrying value of the asset. We evaluate the allowance for loan losses based on the combined total of the impaired and general components for loans. Generally when the loan portfolio increases, absent other factors, our allowance for loan loss methodology results in a higher dollar amount of estimated incurred losses. Conversely, when the loan portfolio decreases, absent other factors, our allowance for loan loss methodology results in a lower dollar amount of estimated incurred losses. Each quarter we evaluate the allowance for loan losses and adjust the allowance as appropriate through a provision for loan losses. While we use the best information available to make evaluations, future adjustments to the allowance may be necessary if conditions differ substantially from the information used in making the evaluations. In addition, as an integral part of their examination process, the Office of the Comptroller of the Currency (OCC) will periodically review the allowance for loan losses. The OCC may require us to adjust the allowance based on their analysis of information available to them at the time of their examination. A summary of changes in the allowance for loan losses for the years ended December 31, 2017 , 2016 , and 2015 follows (in thousands): December 31, 2017 2016 2015 Balance at beginning of year $ 24,595 $ 24,770 $ 26,292 Provision for loan losses 1,411 635 353 Recoveries 556 194 140 Charge-offs (402 ) (1,004 ) (2,015 ) Balance at end of year $ 26,160 $ 24,595 $ 24,770 The following table sets forth activity in our allowance for loan losses, by loan type, for the years ended December 31, 2017 and 2016 . The following table also details the amount of loans receivable held-for-investment, net of deferred loan fees and costs, that are evaluated individually, and collectively, for impairment, and the related portion of allowance for loan losses that is allocated to each loan portfolio segment (in thousands): December 31, 2017 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Unallocated Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 5,432 $ 664 $ 172 $ 14,952 $ 588 $ 1,720 $ 96 $ — $ 23,624 $ 896 $ 75 $ 24,595 Charge-offs (4 ) — — (184 ) (104 ) (73 ) — — (365 ) — (37 ) (402 ) Recoveries 70 — — 277 97 79 — — 523 — 33 556 Provisions (credit) (302 ) (161 ) 438 2,329 (459 ) (453 ) (2 ) — 1,390 55 (34 ) 1,411 Ending Balance $ 5,196 $ 503 $ 610 $ 17,374 $ 122 $ 1,273 $ 94 $ — $ 25,172 $ 951 $ 37 $ 26,160 Ending balance: individually evaluated for impairment $ — $ 38 $ — $ — $ 4 $ 3 $ — $ — $ 45 $ — $ 37 $ 82 Ending balance: collectively evaluated for impairment $ 5,196 $ 465 $ 610 $ 17,374 $ 118 $ 1,270 $ 94 $ — $ 25,127 $ 951 $ — $ 26,078 Loans, net: Ending Balance $ 445,781 $ 101,650 $ 34,620 $ 1,739,220 $ 67,679 $ 34,893 $ 1,432 $ — $ 2,425,275 $ 22,741 $ 692,803 $ 3,140,819 Ending balance: individually evaluated for impairment $ 16,008 $ 1,996 $ — $ 1,310 $ 69 $ 159 $ — $ — $ 19,542 $ — $ 1,543 $ 21,085 Ending balance: collectively evaluated for impairment $ 429,773 $ 99,654 $ 34,620 $ 1,737,910 $ 67,610 $ 34,734 $ 1,432 $ — $ 2,405,733 $ 22,741 $ 691,260 $ 3,119,734 December 31, 2016 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Unallocated Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 7,106 $ 787 $ 261 $ 12,387 $ 795 $ 1,288 $ 155 $ 1,093 $ 23,872 $ 783 $ 115 $ 24,770 Charge-offs (638 ) (20 ) — (278 ) — (66 ) (2 ) — (1,004 ) — — (1,004 ) Recoveries 181 2 — — 2 4 5 — 194 — — 194 Provisions (credit) (1,217 ) (105 ) (89 ) 2,843 (209 ) 494 (62 ) (1,093 ) 562 113 (40 ) 635 Ending Balance $ 5,432 $ 664 $ 172 $ 14,952 $ 588 $ 1,720 $ 96 $ — $ 23,624 $ 896 $ 75 $ 24,595 Ending balance: individually evaluated for impairment $ 64 $ 66 $ — $ 95 $ 23 $ 5 $ — $ — $ 253 $ — $ 75 $ 328 Ending balance: collectively evaluated for impairment $ 5,368 $ 598 $ 172 $ 14,857 $ 565 $ 1,715 $ 96 $ — $ 23,371 $ 896 $ — $ 24,267 Loans, net: Ending Balance $ 413,352 $ 106,524 $ 14,092 $ 1,510,100 $ 66,767 $ 32,013 $ 1,498 $ — $ 2,144,346 $ 30,498 $ 793,240 $ 2,968,084 Ending balance: individually evaluated for impairment $ 20,710 $ 2,180 $ — $ 1,372 $ 336 $ 101 $ — $ — $ 24,699 $ — $ 1,591 $ 26,290 Ending balance: collectively evaluated for impairment $ 392,642 $ 104,344 $ 14,092 $ 1,508,728 $ 66,431 $ 31,912 $ 1,498 $ — $ 2,119,647 $ 30,498 $ 791,649 $ 2,941,794 The Company monitors the credit quality of its loan portfolio on a regular basis. Credit quality is monitored by reviewing certain credit quality indicators. Management has determined that loan-to-value ratios (at period end) and internally assigned credit risk ratings by loan type are the key credit quality indicators that best measure the credit quality of the Company’s loan receivables. Loan-to-value (“LTV”) ratios used by management in monitoring credit quality are based on current period loan balances and original appraised values at time of origination (unless a current appraisal has been obtained as a result of the loan being deemed impaired). In calculating the provision for loan losses, based on past loan loss experience, management has determined that commercial real estate loans and multifamily loans having loan-to-value ratios, as described above, of less than 35% , and one-to-four family loans having loan-to-value ratios, as described above, of less than 60% , require less of a loss factor than those with higher loan to value ratios. The Company maintains a credit risk rating system as part of the risk assessment of its loan portfolio. The Company’s lending officers are required to assign a credit risk rating to each loan in their portfolio at origination. This risk rating is reviewed periodically and adjusted if necessary. Monthly, management presents monitored assets to the loan committee. In addition, the Company engages a third-party independent loan reviewer that performs semi-annual reviews of a sample of loans, validating the credit risk ratings assigned to such loans. The credit risk ratings play an important role in the establishment of the loan loss provision and the allowance for loan losses for originated loans held-for-investment. After determining the general reserve loss factor for each originated portfolio segment held-for-investment, the originated portfolio segment held-for-investment balance collectively evaluated for impairment is multiplied by the general reserve loss factor for the respective portfolio segment in order to determine the general reserve. When assigning a risk rating to a loan, management utilizes the Bank’s internal nine-point credit risk rating system. 1. Strong 2. Good 3. Acceptable 4. Adequate 5. Watch 6. Special Mention 7. Substandard 8. Doubtful 9. Loss Loans rated 1 to 5 are considered pass ratings. An asset is classified substandard if it is inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. Substandard assets have well defined weaknesses based on objective evidence, and are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Assets classified as doubtful have all of the weaknesses inherent in those classified substandard with the added characteristic that the weaknesses present make collection or liquidation in full highly questionable and improbable based on current circumstances. Assets classified as loss are those considered uncollectible and of such little value that their continuance as assets is not warranted. Assets which do not currently expose the Company to sufficient risk to warrant classification in one of the aforementioned categories, but possess weaknesses, are required to be designated special mention. The following table details the recorded investment of originated loans receivable held-for-investment, net of deferred fees and costs, by loan type and credit quality indicator at December 31, 2017 and 2016 (in thousands): At December 31, 2017 Real Estate Multifamily Commercial One-to-Four Family Construction and Land Home Equity and Lines of Credit Commercial and Industrial Other Total < 35% LTV => 35% LTV < 35% LTV => 35% LTV < 60% LTV => 60% LTV Internal Risk Rating Pass $ 131,792 $ 1,603,947 $ 84,620 $ 346,857 $ 60,400 $ 38,504 $ 34,620 $ 67,426 $ 34,141 $ 1,432 $ 2,403,739 Special Mention — 1,897 410 2,170 683 — — 28 571 — 5,759 Substandard — 1,584 — 11,724 1,470 593 — 225 181 — 15,777 Originated loans held-for-investment, net $ 131,792 $ 1,607,428 $ 85,030 $ 360,751 $ 62,553 $ 39,097 $ 34,620 $ 67,679 $ 34,893 $ 1,432 $ 2,425,275 At December 31, 2016 Real Estate Multifamily Commercial One-to-Four Family Construction and Land Home Equity and Lines of Credit Commercial and Industrial Other Total < 35% LTV => 35% LTV < 35% LTV => 35% LTV < 60% LTV => 60% LTV Internal Risk Rating Pass $ 122,525 $ 1,381,231 $ 65,612 $ 323,842 $ 59,214 $ 43,316 $ 14,092 $ 66,489 $ 31,173 $ 1,498 $ 2,108,992 Special Mention 25 4,636 — 3,852 705 — — 29 696 — 9,943 Substandard 40 1,643 1,179 18,867 1,807 1,482 — 249 144 — 25,411 Originated loans held-for-investment, net $ 122,590 $ 1,387,510 $ 66,791 $ 346,561 $ 61,726 $ 44,798 $ 14,092 $ 66,767 $ 32,013 $ 1,498 $ 2,144,346 Included in loans receivable are loans for which the accrual of interest income has been discontinued due to deterioration in the financial condition of the borrowers. The recorded investment of these nonaccrual loans was $5.5 million and $7.3 million at December 31, 2017 , and December 31, 2016 , respectively. Generally, originated loans are placed on non-accruing status when they become 90 days or more delinquent, or sooner if considered appropriate by management, and remain on non-accrual status until they are brought current, have six consecutive months of performance under the loan terms, and factors indicating reasonable doubt about the timely collection of payments no longer exist. Therefore, loans may be current in accordance with their loan terms, or may be less than 90 days delinquent and still be on a non-accruing status. Non-accrual amounts include loans deemed to be impaired of $3.1 million and $5.7 million at December 31, 2017 , and December 31, 2016 , respectively. Loans on non-accrual status with principal balances less than $500,000 , and therefore not meeting the Company’s definition of an impaired loan, amounted to $2.4 million at December 31, 2017 , and $1.7 million at December 31, 2016 . There was no loans held-for-sale at December 31, 2017 , or December 31, 2016 . Loans past due 90 days or more and still accruing interest were $28,000 and $60,000 at December 31, 2017 , and December 31, 2016 , respectively, and consisted of loans that are well secured and in the process of collection. The following table sets forth the detail, and delinquency status, of originated and acquired non-performing loans (non-accrual loans and loans past due ninety days or more and still accruing), net of deferred fees and costs, at December 31, 2017 and 2016 (in thousands), excluding PCI loans which have been segregated into pools. For PCI loans, each loan pool is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. At December 31, 2017 Total Non-Performing Loans Non-Accruing Loans 0-29 Days Past Due 30-89 Days Past Due 90 Days or More Past Due Total 90 Days or More Past Due and Accruing Total Non-Performing Loans Loans held-for-investment: Real estate loans: Commercial LTV => 35% Substandard $ 432 $ 314 $ 2,305 $ 3,051 $ — $ 3,051 Total commercial 432 314 2,305 3,051 — 3,051 One-to-four family residential LTV < 60% Substandard — 206 328 534 — 534 LTV => 60% Substandard — — 39 39 — 39 Total one-to-four family residential — 206 367 573 — 573 Home equity and lines of credit Substandard 79 — — 79 — 79 Total home equity and lines of credit 79 — — 79 — 79 Commercial and industrial loans Substandard — — 72 72 — 72 Total commercial and industrial loans — — 72 72 — 72 Total non-performing loans held-for-investment 511 520 2,744 3,775 — 3,775 Loans acquired: Real Estate Loans: Commercial LTV < 35% Substandard — — 205 205 — 205 LTV => 35% Substandard — 773 58 831 — 831 Total Commercial — 773 263 1,036 — 1,036 One-to-four family residential LTV < 60% Substandard — 201 — 201 27 228 Total one-to-four family residential — 201 — 201 27 228 Multifamily LTV => 35% Substandard — 417 — 417 — 417 Total Multifamily — 417 — 417 — 417 Home equity and lines of credit Substandard — 28 49 77 — 77 Total home equity and lines of credit — 28 49 77 — 77 Commercial and industrial — — 2 2 — 2 Substandard Total commercial and industrial loans — — 2 2 — 2 Other loans Pass — — — — 1 1 Total other — — — — 1 1 Total non-performing loans acquired — 1,419 314 1,733 28 1,761 Total non-performing loans $ 511 $ 1,939 $ 3,058 $ 5,508 $ 28 $ 5,536 At December 31, 2016 Total Non-Performing Loans Non-Accruing Loans 0-29 Days Past Due 30-89 Days Past Due 90 Days or More Past Due Total 90 Days or More Past Due and Accruing Total Non-Performing Loans Loans held-for-investment: Real estate loans: Commercial LTV => 35% Substandard $ 341 $ — $ 4,882 $ 5,223 $ — $ 5,223 Total commercial 341 — 4,882 5,223 — 5,223 One-to-four family residential LTV < 60% Special Mention — — — — — Substandard 384 383 442 1,209 9 1,218 Total 384 383 442 1,209 9 1,218 LTV => 60% Substandard — — — — 43 43 Total — — — — 43 43 Total one-to-four family residential 384 383 442 1,209 52 1,261 Multifamily LTV < 35% Substandard 40 — — 40 — 40 LTV => 35% Substandard — — 3 3 — 3 Total multifamily 40 — 3 43 — 43 Home equity and lines of credit Substandard — 96 — 96 — 96 Total home equity and lines of credit — 96 — 96 — 96 Total non-performing loans held-for-investment 765 479 5,327 6,571 52 6,623 Loans acquired: Real estate loans: Commercial LTV < 35% Substandard — — 231 231 — 231 LTV => 35% Substandard — — 59 59 — 59 Total commercial — — 290 290 — 290 One-to-four family residential LTV < 60% Substandard 420 — — 420 — 420 Total one-to-four family residential 420 — — 420 — 420 Home equity and lines of credit Substandard — — 31 31 8 39 Total home equity and lines of credit — — 31 31 8 39 Commercial and industrial Substandard — — 9 9 — 9 Total commercial and industrial loans — — 9 9 — 9 Total non-performing loans acquired 420 — 330 750 8 758 Total non-performing loans $ 1,185 $ 479 $ 5,657 $ 7,321 $ 60 $ 7,381 The following table sets forth the detail and delinquency status of originated and acquired loans, net of deferred fees and costs, by performing and non-performing loans at December 31, 2017 and 2016 (in thousands): December 31, 2017 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Loans held-for-investment: Real estate loans: Commercial LTV < 35% Pass $ 84,620 $ — $ 84,620 $ — $ 84,620 Special Mention — 410 410 — 410 Total 84,620 410 85,030 — 85,030 LTV => 35% Pass 346,229 628 346,857 — 346,857 Special Mention 832 1,338 2,170 — 2,170 Substandard 7,675 998 8,673 3,051 11,724 Total 354,736 2,964 357,700 3,051 360,751 Total commercial 439,356 3,374 442,730 3,051 445,781 One-to-four family residential LTV < 60% Pass 57,907 2,493 60,400 — 60,400 Special Mention — 683 683 — 683 Substandard 322 614 936 534 1,470 Total 58,229 3,790 62,019 534 62,553 LTV => 60% Pass 38,504 — 38,504 — 38,504 Substandard 554 — 554 39 593 Total 39,058 — 39,058 39 39,097 Total one-to-four family residential 97,287 3,790 101,077 573 101,650 Construction and land Pass 34,614 6 34,620 — 34,620 Total construction and land 34,614 6 34,620 — 34,620 Multifamily LTV < 35% Pass 131,488 304 131,792 — 131,792 Total 131,488 304 131,792 — 131,792 LTV= > 35% Pass 1,603,714 233 1,603,947 — 1,603,947 Special Mention 638 1,259 1,897 — 1,897 Substandard 83 1,501 1,584 — 1,584 Total 1,604,435 2,993 1,607,428 — 1,607,428 Total multifamily 1,735,923 3,297 1,739,220 — 1,739,220 Home equity and lines of credit Pass 67,426 — 67,426 — 67,426 Special Mention 28 — 28 — 28 Substandard 146 — 146 79 225 Total home equity and lines of credit 67,600 — 67,600 79 67,679 Commercial and industrial loans Pass 34,003 138 34,141 — 34,141 Special Mention 547 24 571 — 571 Substandard 109 — 109 72 181 Total commercial and industrial loans 34,659 162 34,821 72 34,893 Other loans Pass 1,403 29 1,432 — 1,432 Total other loans 1,403 29 1,432 — 1,432 December 31, 2017 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Total originated loans held-for-investment 2,410,842 10,658 2,421,500 3,775 2,425,275 Acquired loans: One-to-four family residential LTV < 60% Pass 250,149 224 250,373 — 250,373 Special Mention 455 — 455 — 455 Substandard 417 150 567 228 795 Total 251,021 374 251,395 228 251,623 LTV => 60% Pass 23,295 — 23,295 — 23,295 Substandard 135 — 135 — 135 Total 23,430 — 23,430 — 23,430 Total one-to-four family residential 274,451 374 274,825 228 275,053 Commercial LTV < 35% Pass 50,035 70 50,105 — 50,105 Special Mention 91 — 91 — 91 Substandard — 181 181 205 386 Total 50,126 251 50,377 205 50,582 LTV => 35% Pass 108,125 158 108,283 — 108,283 Special Mention — 133 133 — 133 Substandard 3,703 430 4,133 831 4,964 Total 111,828 721 112,549 831 113,380 Total commercial 161,954 972 162,926 1,036 163,962 Construction and land Pass 17,201 — 17,201 — 17,201 Total construction and land 17,201 — 17,201 — 17,201 Multifamily LTV < 35% Pass 189,551 — 189,551 — 189,551 Special Mention 78 — 78 — 78 Substandard 153 — 153 — 153 Total 189,782 — 189,782 — 189,782 LTV => 35% Pass 8,950 — 8,950 — 8,950 Substandard — — — 417 417 Total 8,950 — 8,950 417 9,367 Total multifamily 198,732 — 198,732 417 199,149 Home equity and lines of credit Pass 20,291 — 20,291 — 20,291 Substandard 87 — 87 77 164 Total home equity and lines of credit 20,378 — 20,378 77 20,455 Commercial and industrial Pass 16,904 40 16,944 — 16,944 Substandard — — — 2 2 Total commercial and industrial 16,904 40 16,944 2 16,946 Other 36 — 36 1 37 Total loans acquired 689,656 1,386 691,042 1,761 692,803 $ 3,100,498 $ 12,044 $ 3,112,542 $ 5,536 $ 3,118,078 December 31, 2016 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Loans held-for-investment: Real estate loans: Commercial LTV < 35% Pass $ 65,189 $ 423 $ 65,612 $ — $ 65,612 Substandard 1,179 — 1,179 — 1,179 Total 66,368 423 66,791 — 66,791 LTV => 35% Pass 322,307 1,535 323,842 — 323,842 Special Mention 3,852 — 3,852 — 3,852 Substandard 12,600 1,044 13,644 5,223 18,867 Total 338,759 2,579 341,338 5,223 346,561 Total commercial 405,127 3,002 408,129 5,223 413,352 One-to-four family residential LTV < 60% Pass 56,787 2,427 59,214 — 59,214 Special Mention — 705 705 — 705 Substandard 589 — 589 1,218 1,807 Total 57,376 3,132 60,508 1,218 61,726 LTV => 60% Pass 43,316 — 43,316 — 43,316 Substandard 1,439 — 1,439 43 1,482 Total 44,755 — 44,755 43 44,798 Total one-to-four family residential 102,131 3,132 105,263 1,261 106,524 Construction and land Pass 14,092 — 14,092 — 14,092 Total construction and land 14,092 — 14,092 — 14,092 Multifamily LTV < 35% Pass 122,525 — 122,525 — 122,525 Special Mention 25 — 25 — 25 Substandard — — — 40 40 Total 122,550 — 122,550 40 122,590 LTV => 35% Pass 1,380,331 900 1,381,231 — 1,381,231 Special Mention 4,636 — 4,636 — 4,636 Substandard 1,640 — 1,640 3 1,643 Total 1,386,607 900 1,387,507 3 1,387,510 Total multifamily 1,509,157 900 1,510,057 43 1,510,100 Home equity and lines of credit Pass 66,369 120 66,489 — 66,489 Special Mention 29 — 29 — 29 Substandard 153 — 153 96 249 Total home equity and lines of credit 66,551 120 66,671 96 66,767 Commercial and industrial loans Pass 31,040 133 31,173 — 31,173 Special Mention 696 — 696 — 696 Substandard 144 — 144 — 144 Total Commercial and industrial loans 31,880 133 32,013 — 32,013 Other loans Pass 1,452 46 1,498 — 1,498 Total other loans 1,452 46 1,498 — 1,498 Total originated loans held-for-investment 2,130,390 7,333 2,137,723 6,623 2,144,346 December 31, 2016 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Loans acquired: One-to-four family residential LTV < 60% Pass 285,116 21 285,137 — 285,137 Special Mention 502 — 502 — 502 Substandard 654 261 915 420 1,335 Total 286,272 282 286,554 420 286,974 LTV => 60% Pass 30,199 — 30,199 — 30,199 Substandard 259 207 466 — 466 Total 30,458 207 30,665 — 30,665 Total one-to-four family residential 316,730 489 317,219 420 317,639 Commercial LTV < 35% Pass 61,646 7 61,653 — 61,653 Special Mention 286 — 286 — 286 Substandard 406 1,040 1,446 231 1,677 Total 62,338 1,047 63,385 231 63,616 LTV => 35% Pass 119,932 132 120,064 — 120,064 Special Mention 446 138 584 — 584 Substandard 3,419 259 3,678 59 3,737 Total 123,797 529 124,326 59 124,385 Total commercial 186,135 1,576 187,711 290 188,001 Construction and land Substandard 20,887 — 20,887 — 20,887 Total construction and land 20,887 — 20,887 — 20,887 Multifamily LTV < 35% Pass 205,025 — 205,025 — 205,025 Special Mention 99 111 210 — 210 Substandard 156 — 156 — 156 Total 205,280 111 205,391 — 205,391 LTV => 35% Pass 9,569 — 9,569 — 9,569 Special Mention — 429 429 — 429 Total 9,569 429 9,998 — 9,998 Total multifamily 214,849 540 215,389 — 215,389 Home equity and lines of credit Pass 25,340 45 25,385 — 25,385 Substandard — 98 98 39 137 Total home equity and lines of credit 25,340 143 25,483 39 25,522 Commercial and industrial loans Pass 25,419 — 25,419 — 25,419 Substandard — 15 15 9 24 Total Commercial and industrial loans 25,419 15 25,434 9 25,443 Other loans Pass 355 4 359 — 359 Total loans acquired 789,715 2,767 792,482 758 793,240 $ 2,920,105 $ 10,100 $ 2,930,205 $ 7,381 $ 2,937,586 The following table summarizes originated and acquired (subsequent to acquisition) impaired loans as of December 31, 2017 and 2016 (in thousands): At December 31, 2017 December 31, 2016 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With No Allowance Recorded: Real estate loans: Commercial LTV < 35% Substandard $ — $ 139 $ — $ — $ 139 $ — LTV => 35% Pass 6,263 7,150 — 3,911 4,047 — Substandard 9,745 10,560 — 14,780 16,868 — One-to-four family residential LTV < 60% Pass 1,189 1,254 — 633 633 — Substandard 251 251 — 184 184 — LTV => 60% Pass 136 161 — — — — Substandard 135 286 — 620 848 — Multifamily LTV < 35% Substandard 153 153 — 156 156 — LTV => 35% Pass 1,309 1,780 — 63 534 — Home Equity Pass 33 33 — 39 39 — Commercial and industrial loans Substandard 135 135 — 75 75 — With a Related Allowance Recorded: Real estate loans: Commerci

Premises and Equipment, Net

Premises and Equipment, Net	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment, Net	Premises and Equipment, Net At December 31, 2017 and 2016 , premises and equipment, less accumulated depreciation and amortization, consists of the following (in thousands): December 31, 2017 2016 At cost: Land $ 4,018 $ 4,018 Buildings and improvements 8,883 8,856 Capital leases 2,600 2,600 Furniture, fixtures, and equipment 22,677 21,962 Leasehold improvements 28,721 27,398 66,899 64,834 Accumulated depreciation and amortization (41,153 ) (37,924 ) Premises and equipment, net $ 25,746 $ 26,910 Depreciation expense for the years ended December 31, 2017 , 2016 , and 2015 , was $3.2 million , $3.6 million , and $3.4 million , respectively. There were no sales of premises and equipment in 2017 , 2016 , or 2015 .

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposits	Deposits Deposit account balances are summarized as follows (dollars in thousands): As of December 31, 2017 2016 Amount Weighted Average Rate Amount Weighted Average Rate Transaction: Negotiable orders of withdrawal $ 465,140 0.39 % $ 467,440 0.34 % Non-interest bearing checking 407,267 — % 390,484 — % Total transaction 872,407 0.21 % 857,924 0.19 % Savings: Money market 800,854 0.72 % 818,660 0.67 % Savings 424,789 0.18 % 500,926 0.24 % Total savings 1,225,643 0.53 % 1,319,586 0.51 % Certificates of deposit: Under $100,000 401,063 1.42 % 484,480 1.22 % $100,000 or more 337,866 1.51 % 51,597 1.48 % Total certificates of deposit 738,929 1.46 % 536,077 1.24 % Total deposits $ 2,836,979 0.67 % $ 2,713,587 0.55 % The Company had brokered deposits (included in certificates of deposit in the above table) of $150.6 million and $98.8 million at December 31, 2017 and 2016 , respectively. Scheduled maturities of certificates of deposit are summarized as follows (in thousands): December 31, 2017 2018 $ 401,315 2019 157,397 2020 122,899 2021 23,511 2022 33,807 Thereafter — Total $ 738,929 Interest expense on deposits is summarized as follows (in thousands): December 31, 2017 2016 2015 Negotiable order of withdrawal and money market $ 7,336 $ 5,634 $ 2,816 Savings-passbook and statement 897 2,124 2,141 Certificates of deposit 8,153 6,529 5,466 $ 16,386 $ 14,287 $ 10,423

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Borrowings	Borrowings Borrowings consisted of securities sold under agreements to repurchase (repurchase agreements), FHLB advances, floating rate advances, and obligations under capital leases and are summarized as follows (in thousands): December 31, 2017 2016 Repurchase agreements $ 2,000 $ 8,000 Other borrowings: FHLB advances 464,217 453,220 Floating rate advances 5,033 11,463 Obligations under capital leases 299 523 $ 471,549 $ 473,206 FHLB advances are secured by a blanket lien on unencumbered securities and the Company’s FHLB capital stock. Repurchase agreements and FHLB advances have contractual maturities as follows (in thousands): December 31, 2017 FHLB Repurchase Advances Agreements 2018 $ 160,715 $ 2,000 2019 123,502 — 2020 90,000 — 2021 70,000 — 2022 20,000 — $ 464,217 $ 2,000 At December 31, 2017 , repurchase agreements have a weighted average rate of 3.39% , with $2.0 million maturing in the first quarter of 2018. The repurchase agreements are secured primarily by mortgage-backed securities with an amortized cost of $4.7 million , and a fair value of $4.6 million , at December 31, 2017 . At December 31, 2016 , repurchase agreements had a weighted average rate of 3.19% , with $4.0 million maturing in the first quarter of 2017 and $4.0 million maturing in more than 90 days. The repurchase agreements were secured primarily by mortgage-backed securities with an amortized cost of $13.7 million , and a fair value of $13.9 million , at December 31, 2016 . The Company has the ability to obtain additional funding from the FHLB and Federal Reserve Bank discount window of approximately $870.8 million , utilizing unencumbered and unpledged securities of $72.6 million and multifamily loans of $885.3 million at December 31, 2017 . The Company expects to have sufficient funds available to meet current commitments in the normal course of business. Interest expense on borrowings is summarized as follows (in thousands): December 31, 2017 2016 2015 Repurchase agreements $ 137 $ 569 $ 2,446 FHLB advances 7,390 6,743 6,742 Floating rate advances 33 27 17 Obligations under capital leases 30 42 60 $ 7,590 $ 7,381 $ 9,265

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense (benefit) consists of the following (in thousands): December 31, 2017 2016 2015 Federal tax expense (benefit): Current $ 10,113 $ 14,218 $ 11,796 Deferred 14,290 (1,260 ) (2,305 ) 24,403 12,958 9,491 State and local tax expense (benefit): Current 1,672 2,506 1,811 Deferred 903 (1,799 ) 673 2,575 707 2,484 Total income tax expense $ 26,978 $ 13,665 $ 11,975 Reconciliation between the amount of reported total income tax expense and the amount computed by multiplying the applicable statutory income tax rate for the years ended December 31, 2017 , 2016 , and 2015 , is as follows (dollars in thousands): December 31, 2017 2016 2015 Tax expense at statutory rate of 35% $ 18,111 $ 13,928 $ 11,027 Increase (decrease) in taxes resulting from: State tax, net of federal income tax 1,674 460 1,615 Impact of 2017 federal tax reform 10,453 — — Bank owned life insurance (1,885 ) (1,399 ) (1,319 ) ESOP fair market value adjustment 404 352 — Incentive stock options 247 299 210 Uncertain tax position 132 178 51 Merger related costs — 74 201 Excess tax benefits from employee share based payments (2,309 ) — — Other, net 151 (227 ) 190 Income tax expense $ 26,978 $ 13,665 $ 11,975 Federal Tax Reform On December 22, 2017, H.R.1, commonly known as the Tax Cuts and Jobs Act (the “Tax Act”), was signed into law. The Tax Act includes many provisions that will affect our income tax expense, including reducing our federal tax rate from 35% to 21%, effective January 1, 2018. As a result of this rate reduction, we were required to re-measure, through income tax expense in the period of enactment, our deferred tax assets and liabilities using the enacted rate at which we expect them to be recovered or settled. The re-measurement of our net deferred tax asset resulted in additional 2017 income tax expense of $10.5 million . Also on December 22, 2017, the Securities and Exchange Commission released Staff Accounting Bulletin No. 118 (“SAB 118”) to address any uncertainty or diversity of views in practice in accounting for the income tax effects of the Tax Act in situations where a registrant does not have the necessary information available, prepared, or analyzed in reasonable detail to complete this accounting in the reporting period that includes the enactment date. SAB 118 describes three scenarios associated with a company’s status of accounting for the TaxAct: (1) a company reflects the income tax effects of the Tax Act in which the accounting under ASC 740 is complete, (2) a company is able to determine a reasonable estimate for certain effects of tax reform and records that estimate as a provisional amount, or (3) a company is not able to determine a reasonable estimate and therefore continues to apply ASC 740, Income Taxes , based on the provisions of the tax laws in effect immediately prior to tax reform being enacted. SAB 118 allows for a measurement period, not to extend beyond one year from the Tax Act’s enactment date, to complete the necessary accounting. There were no items for which the Company was unable to make reasonable estimates for the effects of the Tax Act changes. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2017 and 2016 , are as follows (in thousands): December 31, 2017 2016 Deferred tax assets: Allowance for loan losses $ 6,836 $ 9,470 Capitalized leases 84 213 Deferred compensation 3,474 5,686 Accrued salaries 2 1,128 Postretirement benefits 381 576 Equity awards 3,582 5,005 Unrealized actuarial losses on post-retirement benefits 93 124 Straight-line leases adjustment 892 1,219 Asset retirement obligation 65 89 Reserve for accrued interest receivable 712 1,116 Reserve for loan commitments 124 193 Employee Stock Ownership Plan 497 642 Other 236 366 Depreciation 2,116 2,509 Fair value adjustments of acquired loans 4,868 10,168 Fair value adjustments of pension benefit obligations 154 250 Unrealized losses on securities 2,070 2,775 Total gross deferred tax assets 26,186 41,529 Deferred tax liabilities: Fair value adjustments of acquired securities 35 82 Fair value adjustments of deposit liabilities 358 547 Deferred loan fees 1,815 1,910 Undistributed earnings related to NSB Realty Trust 939 — Other 37 59 Total gross deferred tax liabilities 3,184 2,598 Net deferred tax asset $ 23,002 $ 38,931 Net deferred tax assets are included in other assets on the consolidated balance sheets. In 2016, the Company recorded net deferred tax assets of approximately $3.9 million as a result of the Hopewell Valley acquisition. The Company has determined that it is not required to establish a valuation reserve for the net deferred tax asset account since it is “more likely than not” that the net deferred tax assets will be realized through future reversals of existing taxable temporary differences, future taxable income and tax planning strategies. The conclusion that it is “more likely than not” that the net deferred tax assets will be realized is based on the history of earnings and the prospects for continued profitability. Management will continue to review the tax criteria related to the recognition of deferred tax assets. As a savings institution, the Bank is subject to a special federal tax provision regarding its frozen tax bad debt reserve. At December 31, 2017 and December 31, 2016 , the Bank’s federal tax bad debt base-year reserve was $5.9 million , with a related net deferred tax liability of $2.8 million , which has not been recognized since the Bank does not expect that this reserve will become taxable in the foreseeable future. Events that would result in taxation of this reserve include redemptions of the Bank’s stock or certain excess distributions by the Bank to the Company. A reconciliation of the Company’s uncertain tax positions are as follows (in thousands): December 31, 2017 2016 2015 Beginning balance $ 459 $ 281 $ 230 Settlements based on tax positions related to prior years (109 ) — — Additions based on tax positions related to prior years 132 178 51 Ending balance $ 482 $ 459 $ 281 The Company recognizes interest and penalties on income taxes in income tax expense. The following years are open for examination or under examination: • Federal tax filings for 2014 through present. • New York State tax filings 2014 through present. The 2013 through 2014 filings are currently under examination. • New York City tax filings 2014 through present. The 2010 through 2012 filings are currently under examination. • State of New Jersey 2014 through present.

Retirement Benefits

Retirement Benefits	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Retirement Benefits	Retirement Benefits The Company has a 401(k) plan for its employees, which grants eligible employees (those salaried employees with at least three months of service) the opportunity to invest from 2% to 15% of their base compensation in certain investment alternatives. The Company contributes an amount equal to 25% of employee contributions on the first 6% of base compensation contributed by eligible employees for the first three years of participation. Subsequent years of participation in excess of three years will increase the Company matching contribution from 25% to 50% of an employee’s contributions, on the first 6% of base compensation contributed by eligible employees. A member becomes fully vested in the Company’s contributions upon (a) completion of five years of service, or (b) normal retirement, early retirement, permanent disability, or death. The Company’s contribution to this plan amounted to approximately $387,000 , $384,000 , and $321,000 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The Company also maintains a profit-sharing plan in which the Company can contribute to the participant’s 401(k) account, at its discretion, up to the legal limit of the Internal Revenue Code. The Company did not contribute to the profit sharing plan during 2017 , 2016 , and 2015 . The Company maintains the Northfield Bank ESOP. The ESOP is a tax-qualified plan designed to invest primarily in the Company’s common stock. The ESOP provides employees with the opportunity to receive a funded retirement benefit from the Bank, based primarily on the value of the Company’s common stock. The ESOP purchased 2,463,884 shares of the Company’s common stock in the Company’s initial public offering at a price of $7.13 per share. This purchase was funded with a loan from Northfield Bancorp, Inc. to the ESOP. The outstanding balance at December 31, 2017 and 2016 was $11.5 million and $12.1 million , respectively. The shares of the Company’s common stock purchased in the initial public offering are pledged as collateral for the loan. Shares are released for allocation to participants as loan payments are made. A total of 99,670 and 97,836 shares were released and allocated to participants of the ESOP for the years ended December 31, 2017 and 2016 , respectively. Cash dividends on unallocated shares are utilized to satisfy required debt payments. Dividends on allocated shares are utilized to prepay debt which releases additional shares to participants. Upon completion of the Company’s second-step conversion, a second ESOP was established for employees in 2013, which purchased 1,422,357 shares of the Company’s common stock at a price of $10.00 per share. The purchase was funded with a loan from Northfield Bancorp, Inc. to the second ESOP. The outstanding balance at December 31, 2017 and 2016 was $12.6 million and $12.9 million , respectively. The shares of the Company’s common stock purchased in the second-step conversion are pledged as collateral for the loan. Shares are released for allocation to participants as loan payments are made. A total of 51,189 and 50,086 shares were released and allocated to participants of the second ESOP for the years ended December 31, 2017 and 2016 , respectively. Cash dividends on unallocated shares are utilized to satisfy required debt payments. Dividends on allocated shares are utilized to prepay debt which releases additional shares to participants. ESOP compensation expense for both plans for the years ended December 31, 2017 , 2016 , and 2015 was $2.2 million , $2.0 million , and $1.9 million , respectively. The Company maintains a Supplemental Employee Stock Ownership Plan (the "SESOP"), a non-qualified plan, that provides supplemental benefits to certain executives who are prevented from receiving the full benefits contemplated by the ESOP’s benefit formula due to tax law limits for tax-qualified plans. The supplemental payments for the SESOP consist of cash payments representing the value of Company shares that cannot be allocated to participants under the ESOPs due to legal limitations imposed on tax-qualified plans. The Company's required contributions to the SESOP plan were $84,000 , $82,000 , and $82,000 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The Company provides post-retirement medical and life insurance to a limited number of retired individuals. The Company also provides retiree life insurance benefits to all qualified employees, up to certain limits. The following tables set forth the funded status and components of postretirement benefit costs at December 31 measurement dates (in thousands): 2017 2016 2015 Accumulated postretirement benefit obligation beginning of year $ 1,697 $ 1,950 $ 1,846 Service cost 11 8 9 Interest cost 57 71 62 Actuarial (gain) loss (8 ) (214 ) 149 Benefits paid (112 ) (118 ) (116 ) Accumulated postretirement benefit obligation end of year 1,645 1,697 1,950 Accrued liability (included in accrued expenses and other liabilities) $ 1,645 $ 1,697 $ 1,950 The following table sets forth the amounts recognized in accumulated other comprehensive income (loss) (in thousands): December 31, 2017 2016 Net loss $ 274 $ 310 Transition obligation — — Prior service cost — — Loss recognized in accumulated other comprehensive income (loss) $ 274 $ 310 The estimated net loss, prior service cost, and transition obligation, that will be amortized from accumulated other comprehensive income (loss) into net periodic cost in 2018, are $25,000 , $0 , and $0 respectively. The following table sets forth the components of net periodic postretirement benefit costs for the years ended December 31, 2017 , 2016 , and 2015 (in thousands): December 31, 2017 2016 2015 Service cost $ 11 $ 8 $ 9 Interest cost 57 71 62 Amortization of transition obligation — — 17 Amortization of prior service costs — 12 38 Amortization of unrecognized loss 28 54 44 Net postretirement benefit cost included in compensation and employee benefits $ 96 $ 145 $ 170 The assumed discount rate related to plan obligations reflects the weighted average of published market rates for high-quality corporate bonds with terms similar to those of the plans expected benefit payments, rounded to the nearest quarter percentage point. The Company’s discount rate and rate of compensation increase used in accounting for the plan are as follows: 2017 2016 2015 Assumptions used to determine benefit obligation at period end: Discount rate 3.25 % 3.50 % 3.75 % Rate of increase in compensation 4.00 % 4.00 % 4.00 % Assumptions used to determine net periodic benefit cost for the year: Discount rate 3.50 % 3.75 % 3.50 % Rate of increase in compensation 4.00 % 4.00 % 4.00 % At December 31, 2017 , a medical cost trend rate of 8.75% decreasing 0.50% per year thereafter until an ultimate rate of 4.75% is reached, was used in the plan’s valuation. The Company’s healthcare cost trend rates are based, among other things, on the Company’s own experience and third-party analysis of recent and projected healthcare cost trends. A one percentage-point change in assumed heath care cost trends would have the following effects (in thousands): One Percentage Point Increase One Percentage Point Decrease 2017 2016 2017 2016 Effect on benefits earned and interest cost $ 4 $ 6 $ (4 ) $ (5 ) Effect on accumulated postretirement benefit obligation 111 121 (100 ) (108 ) A one percentage-point change in assumed heath care cost trends would have the following effects (in thousands): One Percentage Point Increase One Percentage Point Decrease 2017 2016 2015 2017 2016 2015 Aggregate of service and interest components of net periodic cost (benefit) $ 4 $ 6 $ 6 $ (4 ) $ (5 ) $ (4 ) Benefit payments of approximately $112,000 , $118,000 , and $116,000 were made in 2017 , 2016 , and 2015 , respectively. The benefits expected to be paid under the postretirement health benefits plan for the next five years are as follows: $121,000 in 2018 ; $124,000 in 2019 ; $126,000 in 2020 ; $127,000 in 2021 ; and $127,000 in 2022 . The benefit payments expected to be paid in the aggregate for the years 2023 through 2027 are $594,000 . The expected benefits are based on the same assumptions used to measure the Company’s benefit obligation at December 31, 2017 , and include estimated future employee service. The Company maintains a nonqualified plan to provide for the elective deferral of all or a portion of director fees by members of the board of directors, deferral of all or a portion of the compensation and/or annual incentive compensation payable to eligible employees of the Company, and to provide to certain officers of the Company benefits in excess of those permitted to be paid by the Company’s savings plan, ESOP, and profit-sharing plan under the applicable Internal Revenue Code. The plan obligation was approximately $13.7 million and $14.1 million at December 31, 2017 and 2016 , respectively, and is included in accrued expenses and other liabilities on the consolidated balance sheets. Income under this plan was $1.1 million , $503,000 , and $392,000 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The Company invests to fund this future obligation, in various mutual funds designated as trading securities. The securities are marked-to-market through current period earnings as a component of non-interest income. Accrued obligations under this plan are credited or charged with the return on the trading securities portfolio as a component of compensation and benefits expense.

Equity Incentive Plan

Equity Incentive Plan	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plan	Equity Incentive Plan The Company maintains the Northfield Bancorp, Inc. 2008 Equity Incentive Plan (the “ 2008 EIP ” ) which allows the Company to grant common stock or options to purchase common stock at specific prices to directors and employees of the Company. The 2008 EIP provides for the issuance or delivery of up to 4,311,796 shares ( 1,231,941 restricted shares and 3,079,855 stock options) of Northfield Bancorp, Inc. common stock subject to certain plan limitations. As of December 31, 2017 , 3,378 restricted shares and 17,299 stock options remain available for issuance under the 2008 EIP. The stock options and restricted stock granted in 2017 vest in varying installments over a period ranging from 10 to 34 months, the first vesting beginning on May 27, 2018. Prior to 2017, all stock options and restricted stock granted vest in equal installments over a five year period beginning one year from the date of grant. The vesting of options and restricted stock awards may accelerate in accordance with the terms of the 2008 EIP. During 2017, the Company granted to certain directors and employees in aggregate 34,500 restricted shares and 98,244 stock options to purchase Company stock. In 2016, the Company granted to an employee 20,000 restricted shares and 40,000 stock options to purchase Company stock. Stock options were granted at an exercise price equal to the fair value of the Company’s common stock on the grant date based on quoted market prices and all have an expiration period of ten years. The Company is expensing the grant date fair value of all employee and director share-based compensation over the requisite service periods on a straight-line basis. The fair value of stock options granted was estimated utilizing the Black-Scholes option pricing model using the following assumptions: Year Ended December 31, 2017 2016 Grant Date November 1, 2017 September 19, 2017 August 1, 2017 November 16, 2016 Stock options granted 40,000 12,500 45,744 40,000 Risk-free rate of return 2.06 % 1.89 % 1.86 % 1.8 % Volatility 29.22 % 30.06 % 29.46 % 30.07 % Dividend yield 2.37 % 1.98 % 1.91 % 1.74 % Expected life 5.75 5.75 5.75 6.5 The Company also maintains the Northfield Bancorp, Inc. 2014 Equity Incentive Plan (the “ 2014 EIP ” ) which allows the Company to grant common stock or options to purchase common stock at specific prices to directors and employees of the Company. The 2014 EIP provides for the issuance or delivery of up to 4,978,249 shares ( 1,422,357 restricted shares and 3,555,892 stock options) of Northfield Bancorp, Inc. common stock subject to certain plan limitations. As of December 31, 2017 , 148,816 restricted shares and 330,273 stock options remain available for issuance under the 2014 EIP. All stock options and restricted stock granted to date vest in equal installments over a five year period beginning one year from the date of grant. The vesting of options and restricted stock awards may accelerate in accordance with terms of the 2014 EIP. Stock options were granted at an exercise price equal to the fair value of the Company’s common stock on the grant date based on quoted market prices and all have an expiration period of ten years. In May 2015, the Company granted to certain directors and employees 419,000 restricted shares, and 1,090,000 stock options to purchase Company stock. The vesting of options and restricted stock awards may accelerate in accordance with terms of the 2014 EIP. Stock options were granted at an exercise price equal to the fair value of the Company’s common stock on the grant date based on quoted market prices and all have an expiration period of ten years. The fair value of stock options granted on May 27, 2015, was estimated utilizing the Black-Scholes option pricing model using the following assumptions: an expected life of 6.5 years, risk-free rate of return of 1.67% , volatility of 32.06% and a dividend yield of 1.90% . During the years ended December 31, 2017 , 2016 , and 2015 , the Company recorded, $6.2 million , $7.3 million , and $6.8 million of stock-based compensation. The following table is a summary of the Company’s non-vested stock options as of December 31, 2017 , and changes therein during the year then ended: Number of Stock Options Weighted Average Grant Date Fair Value Weighted Average Exercise Price Weighted Average Contractual Life (years) Outstanding- December 31, 2015 6,011,861 $ 3.30 $ 10.93 6.41 Granted 40,000 4.94 18.44 9.88 Forfeited (32,520 ) 4.00 13.78 — Exercised (690,671 ) 2.52 7.84 — Outstanding- December 31, 2016 5,328,670 3.41 11.36 5.78 Granted 98,244 4.04 16.73 9.71 Forfeited (247,484 ) 3.93 13.68 — Exercised (558,743 ) 2.41 7.52 — Outstanding - December 31, 2017 4,620,687 3.51 11.82 5.17 Exercisable - December 31, 2017 3,118,615 $ 3.25 $ 10.75 4.26 Expected future stock option expense related to the non-vested options outstanding as of December 31, 2017 , is $3.9 million over an average period of 1.9 years. The following is a summary of the status of the Company’s restricted shares as of December 31, 2017 , and changes therein during the year then ended: Number of Shares Awarded Weighted Average Grant Date Fair Value Non-vested at December 31, 2015 1,193,862 $ 13.70 Granted 20,000 18.44 Vested (277,580 ) 13.61 Forfeited (12,280 ) 13.87 Non-vested at December 31, 2016 924,002 13.82 Granted 34,500 16.70 Vested (279,660 ) 13.68 Forfeited (92,947 ) 13.92 Non-vested at December 31, 2017 585,895 $ 14.05 Expected future stock award expense related to the non-vested restricted awards as of December 31, 2017 , is $5.4 million over an average period of 1.9 years. Upon the exercise of stock options, management expects to utilize treasury stock as the source of issuance for these shares.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company, in the normal course of business, is party to commitments that involve, to varying degrees, elements of risk in excess of the amounts recognized in the consolidated financial statements. These commitments include unused lines of credit and commitments to extend credit. At December 31, 2017 and 2016 , the following commitment and contingent liabilities existed that are not reflected in the accompanying consolidated financial statements (in thousands): December 31, 2017 2016 Commitments to extend credit $ 43,611 $ 46,069 Unused lines of credit 98,433 78,825 Standby letters of credit 7,000 7,463 The Company’s maximum exposure to credit losses in the event of nonperformance by the other party to these commitments is represented by the contractual amount. The Company uses the same credit policies in granting commitments and conditional obligations as it does for amounts recorded in the consolidated balance sheets. These commitments and obligations do not necessarily represent future cash flow requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary, is based on management’s assessment of risk. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third-party. The guarantees generally extend for a term of up to one year and are fully collateralized. For each guarantee issued, if the customer defaults on a payment to the third-party, the Company would have to perform under the guarantee. The unamortized fee on standby letters of credit approximates their fair value; such fees were insignificant at December 31, 2017 , and at December 31, 2016 . The Company maintains an allowance for estimated losses on commitments to extend credit in other liabilities. At December 31, 2017 and 2016 , the allowance was $442,000 and $475,000 , respectively, and changes to the allowance are recorded as a component of other non-interest expense. At December 31, 2017 , the Company was obligated under non-cancelable operating leases and capitalized leases on property used for banking purposes. Most leases contain escalation clauses and renewal options which provide for increased rentals as well as for increases in certain property costs including real estate taxes, common area maintenance, and insurance. In July 2017, the Company entered into an amendment to the lease contract for its main office premises in Woodbridge, New Jersey, to lease an additional 6,919 square feet of office space in the same building and extend the lease term by 10 years and eight months from July 1, 2018 through February 28, 2029 which will increase the Company's future minimum lease commitments by approximately $9.4 million . In October 2017, the Company entered into a new lease agreement for 3,600 square feet of office space at a branch facility in Staten Island, New York, for a term of 15 years through September 2032 which will increase our future minimum lease commitments by approximately $2.5 million . The projected minimum annual rental payments and receipts under the capitalized leases and operating leases are as follows (in thousands): Rental Payments Capitalized Leases Rental Payments Operating Leases Year ending December 31: 2018 $ 262 $ 4,867 2019 44 5,167 2020 — 5,334 2021 — 4,885 2022 — 4,204 Thereafter — 35,748 Total minimum lease payments $ 306 $ 60,205 Net rental expense included in occupancy expense was approximately $5.3 million , $5.2 million , and $4.6 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively. In the normal course of business, the Company may be a party to various outstanding legal proceedings and claims. In the opinion of management, the consolidated financial statements will not be materially affected by the outcome of such legal proceedings and claims. The Bank has entered into employment and change in control agreements with its President and Chief Executive Officer and the other executive officers of the Company to ensure the continuity of executive leadership, to clarify the roles and responsibilities of executives, and to make explicit the terms and conditions of executive employment. These agreements are for a term of three years subject to review and annual renewal, and provide for certain levels of base annual salary and in the event of a change in control, as defined, or in the event of termination, as defined, certain levels of base salary, bonus payments, and benefits for a period of up to three years.

Regulatory Requirements

Regulatory Requirements	12 Months Ended
	Dec. 31, 2017
Regulatory Requirements [Abstract]
Regulatory Requirements	Regulatory Requirements Federal regulations require federally insured depository institutions to meet several minimum capital standards: a common equity Tier 1 capital to risk-based assets ratio of 4.5% , a Tier 1 capital to risk-based assets ratio of 6.0% , a total capital to risk-based assets of 8.0% , and a 4.0% Tier 1 capital to total assets leverage ratio. These capital requirements were effective January 1, 2015, and are the result of a final rule implementing recommendations of the Basel Committee on Banking Supervision and certain requirements of the Dodd-Frank Act. Under prompt corrective action regulations, the OCC is required to take certain supervisory actions (and may take additional discretionary actions) with respect to an undercapitalized institution. Such actions could have a direct material effect on the institution’s financial statements. The regulations establish a framework for the classification of savings institutions into five categories: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized. Generally, an institution is considered well capitalized if it has a leverage (Tier 1) ratio of 5.0% or greater, a common equity Tier 1 ratio of 6.5% or greater, a Tier 1 risk-based capital ratio of 8.0% or greater, and a total risk-based capital ratio of 10.0% or greater. The foregoing capital ratios are based in part on specific quantitative measures of assets, liabilities, and certain off-balance-sheet items as calculated under regulatory accounting practices. Capital amounts and classifications also are subject to qualitative judgments by the regulators about capital components, risk weighting, and other factors. On January 1, 2015, a final rule issued by the federal bank regulatory agencies became effective which revised their leverage and risk-based capital requirements and the method for calculating risk-weighted assets to make them consistent with agreements that were reached by the Basel Committee on Banking Supervision and certain provisions of the Dodd-Frank Act. Among other things, the new rule establishes a new common equity Tier 1 minimum capital requirement ( 4.5% of risk-weighted assets), increases the minimum Tier 1 capital to risk-based assets requirement (from 4% to 6% of risk-weighted assets) and assigns a higher risk weight ( 150% ) to exposures that are more than 90 days past due or are on non-accrual status, and to certain commercial real estate facilities that finance the acquisition, development, or construction of real property. The final rule also requires unrealized gains and losses on certain “available-for-sale” securities holdings to be included for purposes of calculating regulatory capital requirements unless a one-time opt-in or opt-out election is exercised. The rule limits a banking organization's capital distributions and certain discretionary bonus payments if the banking organization does not hold a “capital conservation buffer” consisting of 2.5% of common equity Tier 1 capital to risk-weighted assets in addition to the amount necessary to meet its minimum risk-based capital requirements. The capital conservation buffer requirement was phased in beginning January 1, 2016 at 0.625% of risk-weighted assets and increases each year until fully phased by January 1, 2019 at 2.5% . For calendar year 2017, the capital conservation buffer was 1.25% . It increased to 1.875% on January 1, 2018. The final rule also implemented consolidated capital requirements for savings and loan holding companies, such as the Company, effective January 1, 2015. Prompt Corrective Management believes that as of December 31, 2017 , and December 31, 2016 , the Bank exceeded all capital adequacy requirements to which it is subject. Further, the most recent OCC notification categorized the Bank as a well-capitalized institution under the prompt corrective action regulations. There have been no conditions or events since that notification that management believes have changed the Bank's classification. The following is a summary of Northfield Bank’s regulatory capital amounts and ratios compared to the regulatory requirements as of December 31, 2017 and 2016 , for classification as a well-capitalized institution and minimum capital (dollars in thousands): For Well For Capital Capitalized Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Common Equity Tier 1 Capital (to risk-weighted assets) $ 559,717 16.70 % $ 150,862 4.50 % $ 217,912 6.50 % Tier 1 Leverage 559,717 14.15 158,220 4.00 197,775 5.00 Tier I capital (to risk-weighted assets) 559,717 16.70 201,150 6.00 268,200 8.00 Total capital (to risk-weighted assets) 586,361 17.49 268,200 8.00 335,250 10.00 As of December 31, 2016: Common Equity Tier 1 Capital (to risk-weighted assets) $ 553,715 17.75 % $ 140,371 4.50 % $ 202,758 6.50 % Tier 1 Leverage 553,715 14.55 152,213 4.00 190,267 5.00 Tier I capital (to risk-weighted assets) 553,715 17.75 187,161 6.00 249,548 8.00 Total capital (to risk-weighted assets) 578,828 18.56 249,548 8.00 311,935 10.00 The following is a summary of the Company's regulatory capital amounts and ratios compared to the regulatory requirements as of December 31, 2017 and 2016 , for classification as a well-capitalized institution and minimum capital (dollars in thousands). For Well For Capital Capitalized Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Common Equity Tier 1 Capital (to risk-weighted assets) $ 604,208 18.02 % $ 150,917 4.50 % $ 217,991 6.50 % Tier 1 Leverage 604,208 15.27 158,254 4.00 197,818 5.00 Tier I capital (to risk-weighted assets) 604,208 18.02 201,222 6.00 268,296 8.00 Total capital (to risk-weighted assets) 630,853 18.81 268,296 8.00 335,370 10.00 As of December 31, 2016: Common Equity Tier 1 Capital (to risk-weighted assets) $ 586,055 18.79 % $ 140,329 4.50 % $ 202,698 6.50 % Tier 1 Leverage 586,055 15.40 152,213 4.00 190,267 5.00 Tier I capital (to risk-weighted assets) 586,055 18.79 187,106 6.00 249,474 8.00 Total capital (to risk-weighted assets) 611,168 19.60 249,474 8.00 380,533 10.00

Fair Value of Measurement

Fair Value of Measurement	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Measurement	Fair Value of Measurement The following table presents the assets reported on the consolidated balance sheet at their estimated fair value as of December 31, 2017 and 2016 , by level within the Fair Value Measurements and Disclosures Topic of the FASB Accounting Standards Codification. Financial assets and liabilities are classified in their entirety based on the level of input that is significant to the fair value measurement. The fair value hierarchy is as follows: • Level 1 Inputs – Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 Inputs – Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (for example, interest rates, volatilities, prepayment speeds, loss severities, credit risks and default rates) or inputs that are derived principally from or corroborated by observable market data by correlations or other means. • Level 3 Inputs – Significant unobservable inputs that reflect the Company’s own assumptions that market participants would use in pricing the assets or liabilities. The following tables summarize financial assets and financial liabilities measured at fair value as of December 31, 2017 and 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands): Fair Value Measurements at December 31, 2017 Using: Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Measured on a recurring basis: Assets: Investment securities: Available-for-sale: Mortgage-backed securities GSE $ 445,224 $ — $ 445,224 $ — Non-GSE 79 — 79 — Debt securities Municipal bonds 349 — 349 Corporate bonds 68,130 — 68,130 — Other securities Equity investments - mutual funds 323 323 — — Other 1,016 — 1,016 — Total available-for-sale 515,121 323 514,798 — Trading securities 9,597 9,597 — — Total $ 524,718 $ 9,920 $ 514,798 $ — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 4,645 $ — $ — $ 4,645 One-to-four family residential mortgage 1,735 — — 1,735 Multifamily 51 — — 51 Home equity and lines of credit 31 — — 31 Total impaired real estate loans 6,462 — — 6,462 Commercial and industrial loans 21 — — 21 Other real estate owned 850 — — 850 Total $ 7,333 $ — $ — $ 7,333 Fair Value Measurements at December 31, 2016 Using: Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Measured on a recurring basis: Assets: Investment securities: Available-for-sale: Mortgage-backed securities GSE $ 448,842 $ — $ 448,842 $ — Non-GSE 270 — 270 — Debt securities Municipal Bonds 2,158 2,158 — Corporate bonds 45,159 45,159 — Other securities Equity investments - mutual funds 1,218 271 947 — Other 1,250 1,250 — Total available-for-sale 498,897 271 498,626 — Trading securities 7,857 7,857 — — Total $ 506,754 $ 8,128 $ 498,626 $ — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 10,730 $ — $ — $ 10,730 One-to-four family residential mortgage 2,177 — — 2,177 Multifamily 1,276 — — 1,276 Home equity and lines of credit 274 — — 274 Total impaired real estate loans 14,457 — — 14,457 Commercial and industrial loans 21 — — 21 Other real estate owned 850 — — 850 Total $ 15,328 $ — $ — $ 15,328 The following table presents qualitative information for Level 3 assets measured at fair value on a non-recurring basis at December 31, 2017 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 6,483 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 3.13% - 6.5% Other real estate owned $ 850 Appraisals Discount for costs to sell 7.0% The following table presents qualitative information for Level 3 assets measured at fair value on a non-recurring basis at December 31, 2016 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 14,478 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 4.75% - 7.5% Other real estate owned $ 850 Appraisals Discount for costs to sell 7.0% Available-for-Sale Securities: The estimated fair values for mortgage-backed securities, GSE bonds, and corporate securities are obtained from a nationally recognized third-party pricing service. The estimated fair values are derived primarily from cash flow models, which include assumptions for interest rates, credit losses, and prepayment speeds. Broker/dealer quotes are utilized as well when such quotes are available and deemed representative of the market. The significant inputs utilized in the cash flow models are based on market data obtained from sources independent of the Company (observable inputs,) and are therefore classified as Level 2 within the fair value hierarchy. The estimated fair value of equity securities classified as Level 1, are derived from quoted market prices in active markets. Equity securities consist primarily of money market mutual funds. There were no transfers of securities between Level 1 and Level 2 during the year ended December 31, 2017 . Trading Securities: Fair values are derived from quoted market prices in active markets. The assets consist of publicly traded mutual funds. Impaired Loans: At December 31, 2017 , and December 31, 2016 , the Company had originated impaired loans held-for-investment with outstanding principal balances of $8.8 million and $17.7 million that were recorded at their estimated fair value of $6.5 million and $14.5 million , respectively. The Company recorded a net decrease in the specific reserve for impaired loans of $246,000 and $562,000 for the years ended December 31, 2017 and 2016 , respectively, and net recoveries of $154,000 and net charge-offs of $810,000 for the years ended December 31, 2017 and 2016 , respectively, utilizing Level 3 inputs. For purposes of estimating fair value of impaired loans, management utilizes independent appraisals, if the loan is collateral dependent, adjusted downward by management, as necessary, for changes in relevant valuation factors subsequent to the appraisal date, or the present value of expected future cash flows for non-collateral dependent loans and troubled debt restructurings. Other Real Estate Owned: At December 31, 2017 and 2016 , the Company had assets acquired through foreclosure of $850,000 , recorded at estimated fair value, less estimated selling costs when acquired, thus establishing a new cost basis. Estimated fair value is generally based on independent appraisals. These appraisals include adjustments to comparable assets based on the appraisers’ market knowledge and experience, and are considered Level 3 inputs. When an asset is acquired, the excess of the loan balance over fair value, less estimated selling costs, is charged to the allowance for loan losses. If the estimated fair value of the asset declines, a write-down is recorded through non-interest expense. The valuation of foreclosed assets is subjective in nature and may be adjusted in the future because of changes in the economic conditions. In addition, the Company may be required, from time to time, to measure the fair value of certain other financial assets on a nonrecurring basis in accordance with U.S. GAAP. The adjustments to fair value usually result from the application of lower-of-cost-or-market accounting or write downs of individual assets. Fair Value of Financial Instruments The FASB Accounting Standards Topic for Financial Instruments requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring or non-recurring basis. The methodologies for estimating the fair value of financial assets and financial liabilities that are measured at fair value on a recurring or non-recurring basis are discussed above. The following methods and assumptions were used to estimate the fair value of other financial assets and financial liabilities not already discussed above: (a) Cash, Cash Equivalents Cash and cash equivalents are short-term in nature with original maturities of three months or less ; the carrying amount approximates fair value. (b) Securities (Held-to-Maturity) The estimated fair values for substantially all of our securities are obtained from an independent nationally recognized pricing service. The independent pricing service utilizes market prices of same or similar securities whenever such prices are available. Prices involving distressed sellers are not utilized in determining fair value. Where necessary, the independent third-party pricing service estimates fair value using models employing techniques such as discounted cash flow analyses. The assumptions used in these models typically include assumptions for interest rates, credit losses, and prepayments, utilizing market observable data where available. (c) Federal Home Loan Bank of New York Stock The fair value for FHLB of New York stock is its carrying value, since this is the amount for which it could be redeemed and there is no active market for this stock. (d) Loans (Held-for-Investment) Fair values are estimated for portfolios of loans with similar financial characteristics. Loans are segregated by type such as originated and purchased, and further segregated by residential mortgage, construction, land, multifamily, commercial and consumer. Each loan category is further segmented into amortizing and non-amortizing and fixed and adjustable rate interest terms and by performing and non-performing categories. The fair value of loans is estimated by discounting the future cash flows using current prepayment assumptions and current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. This method of estimating fair value does not incorporate the exit price concept of fair value prescribed by the FASB ASC Topic for Fair Value Measurements and Disclosures, which would also consider adjustments for other factors such as liquidity and credit quality. The fair value would be affected significantly by these other factors. (e) Loans (Held-for-Sale) Held-for-sale loans are carried at the lower of aggregate cost or estimated fair value, less costs to sell, and therefore fair value is equal to carrying value. (f) Deposits The fair value of deposits with no stated maturity, such as non-interest-bearing demand deposits, savings, NOW and money market accounts, is equal to the amount payable on demand. The fair value of certificates of deposit is based on the discounted value of contractual cash flows. The discount rate is estimated using the rates currently offered for deposits of similar remaining maturities. (g) Commitments to Extend Credit and Standby Letters of Credit The fair value of commitments to extend credit and standby letters of credit are estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the present creditworthiness of the counterparties. For fixed-rate loan commitments, fair value also considers the difference between current levels of interest rates and the committed rates. The fair value of off-balance-sheet commitments is insignificant and therefore not included in the following table. (h) Borrowings The fair value of borrowings is estimated by discounting future cash flows based on rates currently available for debt with similar terms and remaining maturity. (i) Advance Payments by Borrowers for Taxes and Insurance Advance payments by borrowers for taxes and insurance have no stated maturity; the fair value is equal to the amount currently payable. The estimated fair values of the Company’s significant financial instruments at December 31, 2017 and 2016 , are presented in the following table (in thousands): December 31, 2017 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 57,839 $ 57,839 $ — $ — $ 57,839 Trading securities 9,597 9,597 — — 9,597 Securities available-for-sale 515,121 323 514,798 — 515,121 Securities held-to-maturity 9,931 — 9,892 — 9,892 FHLB of New York stock, at cost 25,046 — 25,046 — 25,046 Net loans held-for-investment 3,114,659 — — 3,157,829 3,157,829 Financial liabilities: Deposits $ 2,836,979 $ — $ 2,839,666 $ — $ 2,839,666 Repurchase agreements and other borrowings 471,549 — 466,625 — 466,625 Advance payments by borrowers 14,798 — 14,798 — 14,798 December 31, 2016 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 96,085 $ 96,085 $ — $ — $ 96,085 Trading securities 7,857 7,857 — — 7,857 Securities available-for-sale 498,897 271 498,626 — 498,897 Securities held-to-maturity 10,148 — 10,118 — 10,118 FHLB of New York stock, at cost 25,123 — 25,123 — 25,123 Net loans held-for-investment 2,943,489 — — 2,970,438 2,970,438 Financial liabilities: Deposits $ 2,713,587 $ — $ 2,720,176 $ — $ 2,720,176 Repurchase agreements and other borrowings 473,206 — 472,387 — 472,387 Advance payments by borrowers 12,331 — 12,331 — 12,331 Limitations Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with a high degree of precision. Changes in assumptions could significantly affect the estimates. Fair value estimates are based on existing on- and off-balance sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in the estimates.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following is a summary of the Company’s earnings per share calculations and reconciliation of basic to diluted earnings per share for the periods indicated (in thousands, except share data): December 31, 2017 2016 2015 Net income available to common stockholders $ 24,768 $ 26,130 $ 19,531 Weighted average shares outstanding-basic 45,325,445 44,374,389 42,285,712 Effect of non-vested restricted stock and stock options outstanding 1,550,285 1,343,498 1,192,769 Weighted average shares outstanding-diluted 46,875,730 45,717,887 43,478,481 Earnings per share-basic $ 0.55 $ 0.59 $ 0.46 Earnings per share-diluted $ 0.53 $ 0.57 $ 0.45 Anti-dilutive shares 334,927 777,733 2,679,507 Diluted earnings per share is computed using the same method as basic earnings per share, but reflects the potential dilution that could occur if stock options and unvested shares of restricted stock were exercised and converted into common stock. These potentially dilutive shares would then be included in the weighted average number of shares outstanding for the period using the treasury stock method. The Company adopted ASU No. 2016-09 effective January 1, 2017. The most significant impact of the amended guidance resulted in recognition of excess tax benefits within income tax expense, which resulted in an increase to net income and earnings per share. In addition, the guidance increases average diluted shares, since the Company no longer includes such excess tax benefits in the calculation of diluted shares. For further discussion, see Note 1 - “Summary of Significant Accounting Policies - Net Income per Common Share”.

Parent-only Financial Informati

Parent-only Financial Information	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent-only Financial Information	Parent-only Financial Information The following condensed parent company only financial information reflects Northfield Bancorp, Inc.’s investment in its wholly-owned consolidated subsidiary, Northfield Bank, using the equity method of accounting. Northfield Bancorp, Inc. Condensed Balance Sheets December 31, 2017 2016 (in thousands) Assets Cash in Northfield Bank $ 20,080 $ 8,953 Interest-earning deposits in other financial institutions 21 21 Investment in Northfield Bank 594,385 588,856 ESOP loan receivable 24,021 25,043 Other assets 1,185 118 Total assets $ 639,692 $ 622,991 Liabilities and Stockholders' Equity Total liabilities $ 815 $ 1,795 Total stockholders' equity 638,877 621,196 Total liabilities and stockholders' equity $ 639,692 $ 622,991 Northfield Bancorp, Inc. Condensed Statements of Comprehensive Income (Loss) Years Ended December 31, 2017 2016 2015 (in thousands) Interest on ESOP loan $ 939 $ 913 $ 875 Interest income on deposit in Northfield Bank 31 31 51 Gains (losses) on securities transactions, net 5 4 (4 ) Undistributed earnings of Northfield Bank 24,887 26,303 19,718 Total income 25,862 27,251 20,640 Other expenses 872 936 891 Income tax expense 222 185 218 Total expense 1,094 1,121 1,109 Net income $ 24,768 $ 26,130 $ 19,531 Comprehensive income: Net income $ 24,768 $ 26,130 $ 19,531 Other comprehensive loss, net of tax (227 ) (1,346 ) (2,221 ) Comprehensive income $ 24,541 $ 24,784 $ 17,310 Northfield Bancorp, Inc. Condensed Statements of Cash Flows December 31, 2017 2016 2015 (in thousands) Cash flows from operating activities Net income $ 24,768 $ 26,130 $ 19,531 Adjustments to reconcile net income to net cash provided by operating activities: Increase in other assets (2,008 ) (1,994 ) (457 ) (Gains) losses on securities transactions, net (5 ) (4 ) 4 (Decrease) increase in other liabilities (980 ) 1,238 377 Undistributed earnings of Northfield Bank (24,887 ) (26,303 ) (19,718 ) Net cash used in operating activities (3,112 ) (933 ) (263 ) Cash flows from investing activities Cash consideration paid for business acquisition — (13,644 ) — Dividends from Northfield Bank 28,763 14,700 25,900 Net cash provided by investing activities 28,763 1,056 25,900 Cash flows from financing activities Principal payments on ESOP loan receivable 1,022 969 922 Purchase of treasury stock — (2,201 ) (48,446 ) Dividends paid (15,646 ) (14,074 ) (12,184 ) Exercise of stock options 100 120 158 Additional tax benefit on stock awards — 1,512 122 Net cash used in financing activities (14,524 ) (13,674 ) (59,428 ) Net increase (decrease) in cash and cash equivalents 11,127 (13,551 ) (33,791 ) Cash and cash equivalents at beginning of year 8,974 22,525 56,316 Cash and cash equivalents at end of year $ 20,101 $ 8,974 $ 22,525

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) The following tables are a summary of certain quarterly financial data for the years ended December 31, 2017 and 2016 : 2017 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 32,069 $ 32,660 $ 33,525 $ 34,615 Interest expense 5,392 5,751 6,173 6,660 Net interest income 26,677 26,909 27,352 27,955 Provision for loan losses 372 511 488 40 Net interest income after provision for loan losses 26,305 26,398 26,864 27,915 Other income 4,147 2,437 2,615 2,443 Other expenses 17,544 16,618 16,828 16,388 Income before income tax expense 12,908 12,217 12,651 13,970 Income tax expense 2,960 3,807 4,525 15,686 Net income (loss) $ 9,948 $ 8,410 $ 8,126 $ (1,716 ) Net income per basic common share $ 0.22 $ 0.19 $ 0.18 $ (0.04 ) Net income per diluted common share $ 0.21 $ 0.18 $ 0.17 $ (0.04 ) 2016 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 30,169 $ 31,168 $ 31,525 $ 32,110 Interest expense 5,441 5,527 5,274 5,426 Net interest income 24,728 25,641 26,251 26,684 Provision (recoveries) for loan losses (131 ) 14 472 280 Net interest income after provision for loan losses 24,859 25,627 25,779 26,404 Other income 2,229 2,533 2,667 2,643 Other expenses 21,499 17,494 17,377 16,576 Income before income tax expense 5,589 10,666 11,069 12,471 Income tax expense 1,929 3,681 3,782 4,273 Net income $ 3,660 $ 6,985 $ 7,287 $ 8,198 Net income per basic common share $ 0.08 $ 0.16 $ 0.16 $ 0.18 Net income per diluted common share $ 0.08 $ 0.15 $ 0.16 $ 0.18

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements are comprised of the accounts of Northfield Bancorp, Inc. and its wholly owned subsidiaries, Northfield Investment, Inc. and Northfield Bank (the “Bank”), and the Bank’s wholly-owned significant subsidiaries, NSB Services Corp. and NSB Realty Trust. All significant intercompany accounts and transactions have been eliminated in consolidation. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheets and revenues and expenses during the reporting periods. Actual results may differ significantly from those estimates and assumptions. A material estimate that is particularly susceptible to significant change in the near term is the allowance for loan losses. In connection with the determination of this allowance, management generally obtains independent appraisals for significant properties. In addition, judgments related to the amount and timing of expected cash flows from purchased credit-impaired (“PCI”) loans, goodwill, securities valuation and impairment, and deferred income taxes, involve a higher degree of complexity and subjectivity and require estimates and assumptions about uncertain matters. Actual results may differ from the estimates and assumptions. Certain prior year amounts have been reclassified to conform to the current year presentation.
Business	Business The Company, through its principal subsidiary, the Bank, provides a full range of banking services primarily to individuals and corporate customers in Richmond and Kings counties in New York, and Hunterdon, Mercer, Union and Middlesex counties in New Jersey. The Company is subject to competition from other financial institutions and to the regulations of certain federal and state agencies, and undergoes periodic examinations by those regulatory authorities.
Cash Equivalents	Cash Equivalents Cash equivalents consist of cash on hand, due from banks, and interest-bearing deposits in other financial institutions with an original term of three months or less.
Securities	Securities Securities are classified at the time of purchase, based on management’s intention, as securities held-to-maturity, securities available-for-sale, or trading account securities. Securities held-to-maturity are those that management has the positive intent and ability to hold until maturity. Securities held-to-maturity are carried at amortized cost, adjusted for amortization of premiums and accretion of discounts using the level-yield method over the contractual term of the securities, adjusted for actual prepayments. Securities available-for-sale represents all securities not classified as either held-to-maturity or trading. Securities available-for-sale are carried at estimated fair value with unrealized holding gains and losses (net of related tax effects) on such securities excluded from earnings, but included as a separate component of stockholders’ equity, titled “Accumulated other comprehensive income (loss).” The cost of securities sold is determined using the specific-identification method. Security transactions are recorded on a trade-date basis. Trading securities are securities that are bought and may be held for the purpose of selling them in the near term. Trading securities are reported at estimated fair value, with unrealized holding gains and losses reported as a component of gain (loss) on securities transactions, net in non-interest income. Our evaluation of other-than-temporary impairment considers our assessments of the reason for the decline in value, the duration and severity of the impairment, our intent and ability to hold the securities (as well as the likelihood of a near-term recovery), and our intent to sell the securities and whether it is more likely than not that we will be required to sell the securities before the recovery of their amortized cost basis. If a determination is made that a debt security is other-than-temporarily impaired, the Company will estimate the amount of the unrealized loss that is attributable to credit and all other non-credit related factors. If we intend to hold securities in an unrealized loss position until the loss is recovered, which may be at maturity, the credit related component will be recognized as an other-than-temporary impairment charge in non-interest income. The non-credit related component will be recorded as an adjustment to accumulated other comprehensive income (loss), net of tax. The estimated fair value of debt securities, including mortgage-backed securities and corporate debt obligations is furnished by an independent third-party pricing service. The third-party pricing service primarily utilizes pricing models and methodologies that incorporate observable market inputs, including among other things, benchmark yields, reported trades, and projected prepayment and default rates. Management reviews the data and assumptions used in pricing the securities by its third-party provider for reasonableness.
Loans	Loans The accounting and reporting for PCI loans and loans classified as held-for-sale differs substantially from those loans originated and classified by the Company as held-for-investment. For purposes of reporting, discussion and analysis, management has classified its loan portfolio into four categories: (1) loans originated by the Company and held-for-sale, which are carried at the lower of aggregate cost or estimated fair value, less costs to sell, and therefore have no associated allowance for loan losses, (2) PCI loans, which are held-for-investment, and initially valued at estimated fair value on the date of acquisition, with no initial related allowance for loan losses, (3) originated loans held-for-investment, which are carried at amortized cost, less net charge-offs and the allowance for loan losses, and (4) acquired loans with no evidence of credit deterioration, which are held-for-investment, and initially valued at an estimated fair value on the date of acquisition, with no initial related allowance for loan losses. Originated and acquired net loans held-for-investment are stated at unpaid principal balance, adjusted by unamortized premiums and unearned discounts, deferred origination fees and certain direct origination costs, and the allowance for loan losses. Interest income on loans is accrued and credited to income as earned. Net loan origination fees/costs are deferred and accreted/amortized to interest income over the loan’s contractual life using the level-yield method, adjusted for actual prepayments. Generally, loans held-for-sale are designated at time of origination and generally consist of newly originated fixed rate residential loans and are recorded at the lower of aggregate cost or estimated fair value in the aggregate. Transfers of loans from held-for-investment to held-for-sale are infrequent and occur at fair value less costs to sell, with any charge-off to allowance for loan losses. Gains are recognized on a settlement-date basis and are determined by the difference between the net sales proceeds and the carrying value of the loans, including any net deferred fees or costs. Originated and acquired net loans held-for-investment are deemed impaired when it is probable, based on current information, that the Company will not collect all amounts due in accordance with the contractual terms of the loan agreement. The Company has defined the population of originated and acquired impaired loans to be all originated and acquired non-accrual loans held-for-investment with an outstanding balance of $500,000 or greater and all loans restructured in troubled debt restructurings (TDRs). Originated and acquired impaired loans held-for-investment are individually assessed to determine that the loan’s carrying value is not in excess of the expected future cash flows, discounted at the loan's original effective interest rate, or the fair value of the underlying collateral (less estimated costs to sell) if the loan is collateral dependent. Impairments, if any, are recognized through a charge to the allowance for loan losses for the amount that the loan’s carrying value exceeds the discounted cash flow analysis or estimated fair value of collateral (less estimated costs to sell) if the loan is collateral dependent. Such amounts are charged-off when considered appropriate. The allowance for loan losses is increased by the provision for loan losses charged against income and is decreased by charge-offs, net of recoveries. Loan losses are charged-off in the period the loans, or portion thereof, are deemed uncollectible. Generally, the Company will record a loan charge-off (including a partial charge-off) to reduce a loan to the estimated fair value of the underlying collateral, less cost to sell, if it is determined that it is probable that recovery will come primarily from the sale or operation of such collateral. Specific reserves on impaired loans that are not considered collateral dependent are charged-off when such amounts are not considered to be collectible. The provision for loan losses is based on management’s evaluation of the adequacy of the allowance that considers, among other things, impaired loans held-for-investment, deterioration in PCI loans subsequent to acquisition, past loan loss experience, known and inherent risks in the portfolio, and existing adverse situations that may affect borrowers’ ability to repay. Additionally, management evaluates changes, if any, in underwriting standards, collection, charge-off and recovery practices, the nature or volume of the portfolio, lending staff, concentration of loans, as well as current economic conditions, and other relevant factors. Management believes the allowance for loan losses is adequate to provide for probable and reasonably estimable incurred losses at the date of the consolidated balance sheets. The Company also maintains an allowance for estimated losses on off-balance sheet credit risks related to loan commitments and standby letters of credit. Management utilizes a methodology similar to its allowance for loan loss adequacy methodology to estimate losses on these commitments. The allowance for estimated credit losses on off-balance sheet commitments is included in other liabilities and any changes to the allowance are recorded as a component of other non-interest expense. While management uses available information to estimate probable and reasonably estimable incurred losses on loans, future additions may be necessary based on changes in conditions, including changes in economic conditions, particularly in Richmond and Kings counties in New York, and Hunterdon, Mercer, Union and Middlesex counties in New Jersey and to a lesser extent eastern Pennsylvania. Accordingly, as with most financial institutions in the market area, the ultimate collectability of a substantial portion of the Company’s loan portfolio is susceptible to changes in conditions in the Company’s marketplace. In addition, future changes in laws and regulations could make it more difficult for the Company to collect all contractual amounts due on its loans and mortgage-backed securities. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance based on their judgments about information available to them at the time of their examination. TDRs are loans where terms have been modified because of deterioration in the financial condition of the borrower. Modifications could include extension of the repayment terms of the loan, reduced interest rates, or forgiveness of accrued interest and/or principal. Once an obligation has been restructured because of such credit problems, it continues to be considered restructured until paid in full or, if the obligation yields a market rate (a rate equal to the rate the Company was willing to accept at the time of the restructuring for a new loan with comparable risk), until the year subsequent to the year in which the restructuring takes place, provided the borrower has performed under the modified terms for a six-month period. The Company records an impairment charge equal to the difference between the present value of estimated future cash flows under the restructured terms discounted at the original loan’s effective interest rate, or the underlying collateral value less costs to sell, if the loan is collateral dependent. Changes in present values attributable to the passage of time are recorded as a component of the provision for loan losses. A loan is considered past due when it is not paid in accordance with its contractual terms. The accrual of income on loans, including impaired loans held-for-investment, and other loans in the process of foreclosure, is generally discontinued when a loan becomes 90 days or more delinquent, or sooner when certain factors indicate that the ultimate collection of principal and interest is in doubt. Loans on which the accrual of income has been discontinued are designated as non-accrual loans. All previously accrued interest is reversed against interest income, and income is recognized subsequently only in the period that cash is received, provided no principal payments are due and the remaining principal balance outstanding is deemed collectible. A non-accrual loan is not returned to accrual status until both principal and interest payments are brought current and factors indicating doubtful collection no longer exist, including performance by the borrower under the loan terms for a consecutive six-month period. The Company accounts for the PCI loans based on expected cash flows. In accordance with current accounting guidance, the Company will maintain the integrity of a pool of multiple loans accounted for as a single asset and evaluate the pools for impairment, and accrual status, based on variances from the expected cash flows.
Federal Home Loan Bank Stock	Federal Home Loan Bank Stock The Bank, as a member of the Federal Home Loan Bank (FHLB) of New York, is required to hold shares of capital stock in the FHLB as a condition to both becoming a member and engaging in certain transactions with the FHLB. The minimum investment requirement is determined by a “membership” investment component and an “activity-based” investment component. The membership investment component is the greater of 0.125% of the Bank’s mortgage-related assets, as defined by the FHLB, or $1,000 . The activity-based investment component is equal to 4.5% of the Bank’s outstanding advances with the FHLB. The activity-based investment component also considers other transactions, including assets originated for or sold to the FHLB, and delivery commitments issued by the FHLB. The Company currently does not enter into these other types of transactions with the FHLB. On a quarterly basis, we perform our other-than-temporary impairment analysis of FHLB stock, we evaluate, among other things, (i) its earnings performance, including the significance of any decline in net assets of the FHLB as compared to the regulatory capital amount of the FHLB, (ii) the commitment by the FHLB to continue dividend payments, and (iii) the liquidity position of the FHLB. We did not consider our investment in FHLB stock to be other-than-temporarily impaired at December 31, 2017 and 2016 .
Premises and Equipment, Net	Premises and Equipment, Net Premises and equipment, including leasehold improvements, are carried at cost, less accumulated depreciation and amortization. Depreciation and amortization of premises and equipment, including capital leases, are computed on a straight-line basis over the estimated useful lives of the related assets. The estimated useful lives of significant classes of assets are generally as follows: buildings - forty years; furniture and equipment - five to seven years; and purchased computer software - three years. Leasehold improvements are amortized over the shorter of the term of the related lease or the estimated useful lives of the improvements. Major improvements are capitalized, while repairs and maintenance costs are charged to operations as incurred. Upon retirement or sale, any gain or loss is credited or charged to operations.
Bank Owned Life Insurance	Bank Owned Life Insurance The Company has purchased bank owned life insurance contracts to help fund its obligations for certain employee benefit costs. The Company’s investment in such insurance contracts has been reported in the consolidated balance sheets at their cash surrender values. Changes in cash surrender values and death benefit proceeds received in excess of the related cash surrender values are recorded as non-interest income.
Goodwill	Goodwill Intangible assets resulting from acquisitions under the purchase method of accounting consist of goodwill and other intangible assets. Goodwill is not amortized and is subject to an annual assessment for impairment. The goodwill impairment analysis is generally a two-step test. However, under current accounting guidance, first we may assess qualitative factors to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. Under current accounting guidance, we are not required to calculate the fair value of a reporting unit if, based on a qualitative assessment, we determine that it was more likely than not that the unit’s fair value was not less than its carrying amount. For the year ended December 31, 2017 , we elected to perform step one of the two-step goodwill impairment test for our reporting unit. Goodwill is allocated to Northfield’s reporting unit at the date goodwill is actually recorded. If the carrying value of a reporting unit exceeds its estimated fair value, a second step in the analysis is performed to determine the amount of impairment, if any. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill. If the carrying value of a reporting unit exceeds the implied fair value of the goodwill, an impairment charge is recorded equal to the excess amount in the current period earnings. As of December 31, 2017 , the carrying value of goodwill totaled $38.4 million . The Company performed its annual goodwill impairment test, as of December 31, 2017 , and determined that the fair value of the Company’s single reporting unit to be in excess of its carrying value. The Company will test goodwill for impairment between annual test dates if an event occurs or circumstances change that would indicate the fair value of the reporting unit is below its carrying amount. No events have occurred and no circumstances have changed since the annual impairment test date that would indicate the fair value of the reporting unit is below its carrying amount.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply in the year in which those temporary differences are expected to be recovered or settled. When applicable, deferred tax assets are reduced by a valuation allowance for any portions determined not likely to be realized. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Income tax benefits are recognized and measured based upon a two-step model: 1) a tax position must be more-likely-than-not to be sustained based solely on its technical merits in order to be recognized, and 2) the benefit is measured as the largest dollar amount of that position that is more-likely-than-not to be sustained upon settlement. The difference between the benefit recognized and the tax benefit claimed on a tax return is referred to as an unrecognized tax benefit. The Company records income tax-related interest and penalties, if applicable, within income tax expense.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted (and without interest) net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell.
Securities Sold Under Agreements to Repurchase and Other Borrowings	Securities Sold Under Agreements to Repurchase and Other Borrowings The Company enters into sales of securities under agreements to repurchase (Repurchase Agreements) and collateral pledge agreements (Pledge Agreements) with selected dealers and banks. Such agreements are accounted for as secured financing transactions since the Company maintains effective control over the transferred or pledged securities and the transfer meets the other accounting and recognition criteria as required by the transfer and servicing topic of the Financial Accounting Standards Board (FASB) Accounting Standards. Obligations under these agreements are reflected as a liability in the consolidated balance sheets. Securities underlying the agreements are maintained at selected dealers and banks as collateral for each transaction executed and may be sold or pledged by the counterparty. Collateral underlying Repurchase Agreements that permit the counterparty to sell or pledge the underlying collateral is disclosed on the consolidated balance sheets as “encumbered.” The Company retains the right under all Repurchase Agreements and Pledge Agreements to substitute acceptable collateral throughout the terms of the agreement.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) includes net income and the change in unrealized holding gains and losses on securities available-for-sale, change in actuarial gains and losses on other post-retirement benefits, and change in service cost on other postretirement benefits, net of taxes. Comprehensive income (loss) and its components is presented in the Consolidated Statements of Comprehensive Income.
Benefits	Benefits The Company sponsors a defined postretirement benefit plan that provides for medical and life insurance coverage to a limited number of retirees, as well as life insurance to all qualifying employees of the Company. The estimated cost of postretirement benefits earned is accrued during an individual’s estimated service period to the Company. The Company recognizes in its balance sheet the over-funded or under-funded status of a defined benefit postretirement plan measured as the difference between the fair value of plan assets and the benefit obligation at the end of our calendar year. The actuarial gains and losses and the prior service costs and credits that arise during the period are recognized as a component of other comprehensive income (loss), net of tax. Funds borrowed by the Employee Stock Ownership Plan (the “ESOP”) from the Company to purchase the Company’s common stock are being repaid from the Bank’s contributions over a period of up to 30 years. The Company’s common stock not yet allocated to participants is recorded as a reduction of stockholders’ equity at cost. The Company records compensation expense related to the ESOP at an amount equal to the shares committed to be released by the ESOP multiplied by the average fair value of our common stock during the reporting period. The Company recognizes the grant-date fair value of stock based awards issued to participants' as compensation cost in the consolidated statements of comprehensive income (loss). The fair value of common stock awards is based on the closing price of our common stock as reported on the NASDAQ Stock Market on the grant date. The expense related to stock options is based on the estimated fair value of the options at the date of the grant using the Black-Scholes pricing model. The awards are fixed in nature and compensation cost related to stock based awards is recognized on a straight-line basis over the requisite service periods. The Bank has a 401(k) plan covering substantially all employees. Contributions to the plan are expensed as incurred.
Segment Reporting	Segment Reporting As a community-focused financial institution, substantially all of the Company’s operations involve the delivery of loan and deposit products to customers. Management makes operating decisions and assesses performance based on an ongoing review of these community banking operations, which constitute the Company’s only operating segment for financial reporting purposes.
Net Income per Common Share	Net Income per Common Share Net income per common share-basic is computed by dividing the net income available to common stockholders by the weighted average number of common shares outstanding, excluding unallocated ESOP shares and unearned common stock award shares. The weighted average common shares outstanding includes the average number of shares of common stock outstanding, including shares allocated or committed to be released ESOP shares. Net income per common share-diluted is computed using the same method as basic earnings per share, but reflects the potential dilution that could occur if stock options and unvested shares of restricted stock were exercised and converted into common stock. These potentially dilutive shares are included in the weighted average number of shares outstanding for the period using the treasury stock method. In March 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, a new standard that simplifies certain aspects of accounting for share-based payments. The Company adopted ASU No. 2016-09 effective January 1, 2017. The update amended the diluted earnings per share calculation in that excess tax benefits are no longer included in assumed proceeds when determining average diluted shares outstanding under the treasury stock method. This guidance is required to be applied prospectively upon adoption. For further discussion, see - Recent Accounting Developments. When applying the treasury stock method for the year ended December 31, 2017, we added the assumed proceeds from option exercises and the average unamortized compensation costs related to unvested shares of restricted stock and stock options. We then divided this sum by our average stock price for the period to calculate assumed shares repurchased. The excess of the number of shares issuable over the number of shares assumed to be repurchased is added to basic weighted average common shares to calculate diluted earnings per share. For the years ended December 31, 2016, and 2015, we added (1) the assumed proceeds from option exercises; (2) the tax benefit, that would have been credited to additional paid-in capital assuming exercise of non-qualified stock options and vesting of shares of restricted stock; and (3) the average unamortized compensation costs related to unvested shares of restricted stock and stock options. We then divided this sum by our average stock price for the period to calculate assumed shares repurchased. The excess of the number of shares issuable over the number of shares assumed to be repurchased is added to basic weighted average common shares to calculate diluted earnings per share.
Other Real Estate Owned	Other Real Estate Owned Assets acquired through loan foreclosure, or deed-in-lieu of, are held for sale and are initially recorded at estimated fair value less estimated selling costs when acquired, thus establishing a new cost basis. Costs after acquisition are generally expensed. If the estimated fair value of the asset subsequently declines, a write-down is recorded through other non-interest expense.
Recent Accounting Developments	Recent Accounting Developments Accounting Pronouncements Adopted in 2017 In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which allows an entity to elect a reclassification from accumulated other comprehensive income (AOCI) to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The amendment states that if an entity elects to reclassify the income tax effects, the amount of that reclassification should include the effect of the change in the tax rate on the gross deferred tax amounts and related valuation allowances, in addition to other income tax effects on items remaining in AOCI. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years with early adoption permitted in a period for which financial statements have not yet been issued. The Company early adopted ASU 2018-02 retrospectively to December 31, 2017, which resulted in the reclassification from AOCI to retained earnings of $892,000 , reflected in the Consolidated Statements of Changes in Stockholders' Equity. In March 2016, the FASB issued ASU No. 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting , a new standard that simplifies certain aspects of accounting for share-based payments. The amendments include the following: • Excess tax benefits and deficiencies resulting from exercise or vesting of stock awards are recorded as income tax expense or benefit on the income statement. Previously, excess tax benefits and certain tax deficiencies were recorded as equity in additional paid-in capital. This update is required to be applied prospectively upon adoption. • For diluted earnings per share calculations, excess tax benefits are no longer included in assumed proceeds when determining average diluted shares outstanding under the treasury stock method, resulting in changes to average diluted shares outstanding. This update is required to be applied prospectively upon adoption. • Excess tax benefits or deficiencies are included as income tax expense as discrete items in the period in which they occur, which impact the effective tax rate in each reporting period; however, these discrete items are not included in the projected annual effective tax rate calculation. This update is required to be applied prospectively upon adoption. • Excess tax benefits are presented as cash flows from operating activities. Previously, excess tax benefits were included as a cash inflow from financing activities. This update may be applied either prospectively or retrospectively upon adoption. The Company applied this update prospectively upon adoption and prior periods have not been adjusted. • Cash paid by an employer to taxing authorities when withholding shares for tax withholding purposes is presented as cash outflows from financing activities, which is consistent with the manner in which we have presented such employee withholding taxes in the past. Accordingly, no reclassification for prior periods is required. • An accounting policy election, using a modified retrospective transition method, to account for forfeitures as they occur or estimate the number of awards expected to be forfeited. The Company elected to account for forfeitures as they occur. The Company adopted ASU No. 2016-09 effective January 1, 2017, and upon adoption recorded a cumulative effect adjustment of $2.9 million to the opening balances of retained earnings and additional paid-in-capital. Adoption of ASU No. 2016-09 also resulted in the recognition of a $2.3 million benefit within income tax expense for the year ended December 31, 2017, which resulted in a corresponding increase to net income and earnings per share. In addition, the guidance increases average diluted shares, since the Company no longer includes such excess tax benefits in the calculation of diluted shares. Adoption of this update did not affect the Company's or the Bank's total equity, book value per share, or regulatory capital ratios. Accounting Pronouncements Not Yet Adopted In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The ASU simplifies the subsequent measurement of goodwill impairment by eliminating the requirement to calculate the implied fair value of goodwill (i.e., the current Step 2 of the goodwill impairment test) to measure a goodwill impairment charge. As amended, the goodwill impairment test will consist of one step comparing the fair value of a reporting unit with its carrying amount. A goodwill impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value. The ASU is effective for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim and annual goodwill impairment testing dates after January 1, 2017. The adoption of this pronouncement is not expected to have an effect on the Company's consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which requires that entities include restricted cash and restricted cash equivalents with cash and cash equivalents in the beginning-of-period and end-of-period total amounts shown on the Statement of Cash Flows. Prior to this pronouncement there was no guidance on how to present restricted cash and cash equivalents in the Statement of Cash Flows. ASU No. 2016-18 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, and is required to be applied retrospectively to all periods presented beginning in the year of adoption. The adoption of this pronouncement is not expected to have a material effect on the Company's consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which provides guidance on the classification of certain cash receipts and payments within the statement of cash flows. ASU No. 2016-15 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, and is required to be applied retrospectively to all periods presented beginning in the year of adoption. Since the ASU only impacts classification on the statements of cash flows, adoption will not affect the Company's consolidated financial position, results of operations or its cash and cash equivalents. In June 2016, the FASB issued No. ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires credit losses on most financial assets measured at amortized cost and certain other instruments to be measured using an expected credit loss model (referred to as the current expected credit loss (CECL) model). Under this model, entities will estimate credit losses over the entire contractual term of the instrument from the date of initial recognition of that instrument. Current US GAAP is based on an incurred loss model that delays recognition of credit losses until it is probable the loss has been incurred. Accordingly, it is anticipated that credit losses will be recognized earlier under the CECL model than under the incurred loss model. ASU No. 2016-13 is effective for interim and annual reporting periods beginning after December 15, 2019. The Company has begun evaluating the potential effect of adoption of this pronouncement on its consolidated financial statements by identifying key interpretive issues, assessing its processes, portfolio segmentation, model development, and identifying the data and system requirements against the new guidance to determine what modifications may be required. The Company is also evaluating third-party vendor solutions to assist in the application of the ASU 2016-13. The adoption of ASU 2016-13 may result in an increase in the allowance for loan losses as a result of changing from an incurred loss model, which encompasses allowances for current known and inherent losses within the portfolio, to an expected losses model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. The extent of the effect is indeterminable at this time as it will depend upon the nature and characteristics of the Company's loan portfolio at the adoption date, as well as economic conditions and forecasts at that date. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , which is intended to increase transparency and comparability of accounting for lease transactions. The ASU will require all leases to be recognized on the balance sheet as lease assets and lease liabilities and will require both quantitative and qualitative disclosures regarding key information about leasing arrangements. Lessor accounting is largely unchanged. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within that reporting period. The Company is currently evaluating the potential effect of adoption of this pronouncement on its consolidated financial statements by reviewing its existing lease contracts and service contracts that may include embedded leases. The Company expects a gross-up of its consolidated balance sheet as a result of recognizing lease liabilities and right of use assets; the extent of such gross-up is under evaluation. The Company does not expect adoption of this pronouncement to have a material impact on its results of operations. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities , which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The guidance primarily affects the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, the FASB clarified guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. The accounting for other financial instruments, such as loans, investments in debt securities, and financial liabilities is largely unchanged. ASU No. 2016-01 is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company will adopt the guidance in the first quarter of 2018. Since the Company has minimal equity investments and no financial liabilities valued under the fair value option, adoption will not have a material effect on the Company's consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers using a five-step model that requires entities to exercise judgment when considering the terms of the contracts. ASU No. 2014-09 and subsequent related updates, also require new qualitative and quantitative disclosures, including disaggregation of revenues and descriptions of performance obligations. The Company will adopt the guidance in the first quarter of 2018 using the modified retrospective method. Because the guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other U.S. GAAP, the new revenue recognition standard will not have a material impact on the company's consolidated financial statements. The Company's implementation efforts include the identification of revenue streams within the scope of the guidance, as well as the evaluation of revenue contracts. Based on these efforts, adoption of this guidance will not result in a material change in the timing or amount of revenue recognized from contracts with customers. The guidance includes expanded disclosures to revenue which we are currently in the process of drafting.
Fair Value Measurement	Fair Value of Measurement The following table presents the assets reported on the consolidated balance sheet at their estimated fair value as of December 31, 2017 and 2016 , by level within the Fair Value Measurements and Disclosures Topic of the FASB Accounting Standards Codification. Financial assets and liabilities are classified in their entirety based on the level of input that is significant to the fair value measurement. The fair value hierarchy is as follows: • Level 1 Inputs – Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 Inputs – Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (for example, interest rates, volatilities, prepayment speeds, loss severities, credit risks and default rates) or inputs that are derived principally from or corroborated by observable market data by correlations or other means. • Level 3 Inputs – Significant unobservable inputs that reflect the Company’s own assumptions that market participants would use in pricing the assets or liabilities.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The FASB Accounting Standards Topic for Financial Instruments requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring or non-recurring basis. The methodologies for estimating the fair value of financial assets and financial liabilities that are measured at fair value on a recurring or non-recurring basis are discussed above. The following methods and assumptions were used to estimate the fair value of other financial assets and financial liabilities not already discussed above: (a) Cash, Cash Equivalents Cash and cash equivalents are short-term in nature with original maturities of three months or less ; the carrying amount approximates fair value. (b) Securities (Held-to-Maturity) The estimated fair values for substantially all of our securities are obtained from an independent nationally recognized pricing service. The independent pricing service utilizes market prices of same or similar securities whenever such prices are available. Prices involving distressed sellers are not utilized in determining fair value. Where necessary, the independent third-party pricing service estimates fair value using models employing techniques such as discounted cash flow analyses. The assumptions used in these models typically include assumptions for interest rates, credit losses, and prepayments, utilizing market observable data where available. (c) Federal Home Loan Bank of New York Stock The fair value for FHLB of New York stock is its carrying value, since this is the amount for which it could be redeemed and there is no active market for this stock. (d) Loans (Held-for-Investment) Fair values are estimated for portfolios of loans with similar financial characteristics. Loans are segregated by type such as originated and purchased, and further segregated by residential mortgage, construction, land, multifamily, commercial and consumer. Each loan category is further segmented into amortizing and non-amortizing and fixed and adjustable rate interest terms and by performing and non-performing categories. The fair value of loans is estimated by discounting the future cash flows using current prepayment assumptions and current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. This method of estimating fair value does not incorporate the exit price concept of fair value prescribed by the FASB ASC Topic for Fair Value Measurements and Disclosures, which would also consider adjustments for other factors such as liquidity and credit quality. The fair value would be affected significantly by these other factors. (e) Loans (Held-for-Sale) Held-for-sale loans are carried at the lower of aggregate cost or estimated fair value, less costs to sell, and therefore fair value is equal to carrying value. (f) Deposits The fair value of deposits with no stated maturity, such as non-interest-bearing demand deposits, savings, NOW and money market accounts, is equal to the amount payable on demand. The fair value of certificates of deposit is based on the discounted value of contractual cash flows. The discount rate is estimated using the rates currently offered for deposits of similar remaining maturities. (g) Commitments to Extend Credit and Standby Letters of Credit The fair value of commitments to extend credit and standby letters of credit are estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the present creditworthiness of the counterparties. For fixed-rate loan commitments, fair value also considers the difference between current levels of interest rates and the committed rates. The fair value of off-balance-sheet commitments is insignificant and therefore not included in the following table. (h) Borrowings The fair value of borrowings is estimated by discounting future cash flows based on rates currently available for debt with similar terms and remaining maturity. (i) Advance Payments by Borrowers for Taxes and Insurance Advance payments by borrowers for taxes and insurance have no stated maturity; the fair value is equal to the amount currently payable.

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	The following table summarizes the estimated fair values of the assets acquired and the liabilities assumed at the date of acquisition for Hopewell Valley (in thousands): ASSETS ACQUIRED: January 8, 2016 Cash and cash equivalents, net $ 55,479 Securities available for sale 61,633 Loans 342,566 Accrued interest receivable 1,452 Bank-owned life insurance 11,269 Premises and equipment 5,926 Federal Home Loan Bank of New York stock, at cost 476 Goodwill 22,252 Other intangible assets 2,013 Other assets 5,389 Total assets acquired $ 508,455 LIABILITIES ASSUMED: Deposits $ 456,203 Other borrowings 2,213 Other liabilities 8,318 Total liabilities assumed $ 466,734 Net assets acquired $ 41,721

Securities Available-for-Sale (

Securities Available-for-Sale (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Comparative Summary Of Mortgage-Backed Securities And Other Securities Available-for-Sale	The following is a comparative summary of mortgage-backed securities, debt securities and other securities available-for-sale at December 31, 2017 and 2016 (in thousands): 2017 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: Government sponsored enterprises (GSE) $ 179,320 $ 1,429 $ 2,454 $ 178,295 Real estate mortgage investment conduits (REMICs): GSE 273,501 287 6,859 266,929 Non-GSE 80 — 1 79 452,901 1,716 9,314 445,303 Debt securities: Municipal bonds 343 6 — 349 Corporate bonds 67,927 401 198 68,130 68,270 407 198 68,479 Other securities Equity investments - mutual funds 323 — — 323 Other 1,016 — — 1,016 1,339 — — 1,339 Total securities available-for-sale $ 522,510 $ 2,123 $ 9,512 $ 515,121 2016 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: GSE $ 225,047 $ 2,800 $ 3,298 $ 224,549 REMICs: GSE 230,500 259 6,466 224,293 Non-GSE 280 — 10 270 455,827 3,059 9,774 449,112 Debt securities: Municipal bonds 2,151 13 6 2,158 Corporate bonds 45,373 150 364 45,159 47,524 163 370 47,317 Other securities: Equity investments-mutual funds 1,233 — 15 1,218 Other 1,250 $ — $ — 1,250 2,483 — 15 2,468 Total securities available-for-sale $ 505,834 $ 3,222 $ 10,159 $ 498,897
Summary Of Expected Maturity Distribution Of Debt Securities Available-for-Sale, Other Than Mortgage-Backed Securities	The following is a summary of the expected maturity distribution of debt securities available-for-sale other than mortgage-backed securities at December 31, 2017 (in thousands): Available-for-sale Amortized cost Estimated fair value Due in one year or less $ — $ — Due after one year through five years 58,174 58,285 Due after five years through ten years 10,096 10,194 $ 68,270 $ 68,479
Gross Unrealized Losses On Mortgage-Backed Securities	Gross unrealized losses on mortgage-backed securities, debt securities and other securities available-for-sale, and the estimated fair value of the related securities, aggregated by security category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2017 and 2016 , were as follows (in thousands): December 31, 2017 Less than 12 months 12 months or more Total Unrealized Estimated Unrealized Estimated Unrealized Estimated losses fair value losses fair value losses fair value Mortgage-backed securities: Pass-through certificates: GSE $ 439 $ 48,931 $ 2,015 $ 76,113 $ 2,454 $ 125,044 REMICs: GSE 933 103,644 5,926 139,830 6,859 243,474 Non-GSE — — 1 79 1 79 Debt securities: Corporate bonds 61 11,006 137 15,084 198 26,090 Total $ 1,433 $ 163,581 $ 8,079 $ 231,106 $ 9,512 $ 394,687 December 31, 2016 Less than 12 months 12 months or more Total Unrealized Estimated Unrealized Estimated Unrealized Estimated losses fair value losses fair value losses fair value Mortgage-backed securities: Pass-through certificates: GSE $ 2,703 $ 121,878 $ 595 $ 8,402 $ 3,298 $ 130,280 REMICs: GSE 1,622 75,586 4,844 97,726 6,466 173,312 Non-GSE — — 10 270 10 270 Debt securities: Municipal bonds 6 1,679 — — 6 1,679 Corporate bonds 364 26,022 — — 364 26,022 Other securities 15 947 — — 15 947 Total $ 4,710 $ 226,112 $ 5,449 $ 106,398 $ 10,159 $ 332,510

Securities Held-to-Maturity (Ta

Securities Held-to-Maturity (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Summary Of Mortgage-Backed Securities Held-to-Maturity	The following is a summary of mortgage-backed securities held-to-maturity at December 31, 2017 and 2016 (in thousands): 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 9,931 $ 17 $ 56 $ 9,892 Total securities held-to-maturity $ 9,931 $ 17 $ 56 $ 9,892 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 10,148 $ 29 $ 59 $ 10,118 Total securities held-to-maturity $ 10,148 $ 29 $ 59 $ 10,118
Held-to-Maturity Securities	Gross unrealized losses on mortgage-backed securities held-to-maturity, and the estimated fair value of the related securities, aggregated by security category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2017 and 2016 , were as follows (in thousands): December 31, 2017 Less than 12 months 12 months or more Total Unrealized Estimated Unrealized Estimated Unrealized Estimated losses fair value losses fair value losses fair value Mortgage-backed securities: Pass-through certificates: GSEs $ 7 $ 3,922 $ 49 $ 3,735 $ 56 $ 7,657 Total $ 7 $ 3,922 $ 49 $ 3,735 $ 56 $ 7,657 December 31, 2016 Less than 12 months Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 59 $ 7,466 Total securities held-to-maturity $ 59 $ 7,466

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Net Loans Held-For-Investment	Loans held-for-investment, net, consists of the following (in thousands): December 31, 2017 2016 Originated loans: Real estate loans: Multifamily $ 1,735,712 $ 1,506,335 Commercial mortgage 445,225 412,667 One-to-four family residential mortgage 100,942 105,968 Home equity and lines of credit 66,254 65,437 Construction and land 34,545 14,065 Total real estate loans 2,382,678 2,104,472 Commercial and industrial loans 34,828 31,906 Other loans 1,430 1,497 Deferred loan cost, net 6,339 6,471 Originated loans held-for-investment, net 2,425,275 2,144,346 PCI Loans 22,741 30,498 Loans acquired: One-to-four family residential mortgage 275,053 317,639 Multifamily 199,149 215,389 Commercial mortgage 163,962 188,001 Home equity and lines of credit 20,455 25,522 Construction and land 17,201 20,887 Total acquired real estate loans 675,820 767,438 Commercial and industrial loans 16,946 25,443 Other loans 37 359 Total loans acquired 692,803 793,240 Loans held for investment, net 3,140,819 2,968,084 Allowance for loan losses (26,160 ) (24,595 ) Net loans held-for-investment $ 3,114,659 $ 2,943,489
PCI Loans Acquired	The following table sets forth information regarding the estimates of the contractually required payments, the cash flows expected to be collected, and the estimated fair value of the PCI loans acquired from Hopewell Valley at January 8, 2016 (in thousands): January 8, 2016 Contractually required principal and interest at acquisition $ 16,580 Contractual cash flows not expected to be collected (non-accretable discount) (9,929 ) Expected cash flows to be collected at acquisition 6,651 Interest component of expected cash flows (accretable discount) (845 ) Fair value of acquired loans $ 5,806
Summary Of Changes In Accretable Yields Of Acquired Loans	The following details the accretable yield (in thousands): For The Year Ended December 31, 2017 2016 Balance at the beginning of year $ 24,215 $ 22,853 Acquisition — 845 Accretion into interest income (5,477 ) (5,225 ) Net reclassification from non-accretable difference (1) 5,764 5,742 Balance at end of year $ 24,502 $ 24,215 _______________________ (1) Reclassifications of the non-accretable difference to the accretable yield may occur subsequent to the loan acquisition dates due to increases in expected cash flows of the loans.
Activity In Allowance For Loan Losses	A summary of changes in the allowance for loan losses for the years ended December 31, 2017 , 2016 , and 2015 follows (in thousands): December 31, 2017 2016 2015 Balance at beginning of year $ 24,595 $ 24,770 $ 26,292 Provision for loan losses 1,411 635 353 Recoveries 556 194 140 Charge-offs (402 ) (1,004 ) (2,015 ) Balance at end of year $ 26,160 $ 24,595 $ 24,770
Allowance For Loan Losses And Loans Receivable By Portfolio Segment	The following table sets forth activity in our allowance for loan losses, by loan type, for the years ended December 31, 2017 and 2016 . The following table also details the amount of loans receivable held-for-investment, net of deferred loan fees and costs, that are evaluated individually, and collectively, for impairment, and the related portion of allowance for loan losses that is allocated to each loan portfolio segment (in thousands): December 31, 2017 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Unallocated Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 5,432 $ 664 $ 172 $ 14,952 $ 588 $ 1,720 $ 96 $ — $ 23,624 $ 896 $ 75 $ 24,595 Charge-offs (4 ) — — (184 ) (104 ) (73 ) — — (365 ) — (37 ) (402 ) Recoveries 70 — — 277 97 79 — — 523 — 33 556 Provisions (credit) (302 ) (161 ) 438 2,329 (459 ) (453 ) (2 ) — 1,390 55 (34 ) 1,411 Ending Balance $ 5,196 $ 503 $ 610 $ 17,374 $ 122 $ 1,273 $ 94 $ — $ 25,172 $ 951 $ 37 $ 26,160 Ending balance: individually evaluated for impairment $ — $ 38 $ — $ — $ 4 $ 3 $ — $ — $ 45 $ — $ 37 $ 82 Ending balance: collectively evaluated for impairment $ 5,196 $ 465 $ 610 $ 17,374 $ 118 $ 1,270 $ 94 $ — $ 25,127 $ 951 $ — $ 26,078 Loans, net: Ending Balance $ 445,781 $ 101,650 $ 34,620 $ 1,739,220 $ 67,679 $ 34,893 $ 1,432 $ — $ 2,425,275 $ 22,741 $ 692,803 $ 3,140,819 Ending balance: individually evaluated for impairment $ 16,008 $ 1,996 $ — $ 1,310 $ 69 $ 159 $ — $ — $ 19,542 $ — $ 1,543 $ 21,085 Ending balance: collectively evaluated for impairment $ 429,773 $ 99,654 $ 34,620 $ 1,737,910 $ 67,610 $ 34,734 $ 1,432 $ — $ 2,405,733 $ 22,741 $ 691,260 $ 3,119,734 December 31, 2016 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Unallocated Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 7,106 $ 787 $ 261 $ 12,387 $ 795 $ 1,288 $ 155 $ 1,093 $ 23,872 $ 783 $ 115 $ 24,770 Charge-offs (638 ) (20 ) — (278 ) — (66 ) (2 ) — (1,004 ) — — (1,004 ) Recoveries 181 2 — — 2 4 5 — 194 — — 194 Provisions (credit) (1,217 ) (105 ) (89 ) 2,843 (209 ) 494 (62 ) (1,093 ) 562 113 (40 ) 635 Ending Balance $ 5,432 $ 664 $ 172 $ 14,952 $ 588 $ 1,720 $ 96 $ — $ 23,624 $ 896 $ 75 $ 24,595 Ending balance: individually evaluated for impairment $ 64 $ 66 $ — $ 95 $ 23 $ 5 $ — $ — $ 253 $ — $ 75 $ 328 Ending balance: collectively evaluated for impairment $ 5,368 $ 598 $ 172 $ 14,857 $ 565 $ 1,715 $ 96 $ — $ 23,371 $ 896 $ — $ 24,267 Loans, net: Ending Balance $ 413,352 $ 106,524 $ 14,092 $ 1,510,100 $ 66,767 $ 32,013 $ 1,498 $ — $ 2,144,346 $ 30,498 $ 793,240 $ 2,968,084 Ending balance: individually evaluated for impairment $ 20,710 $ 2,180 $ — $ 1,372 $ 336 $ 101 $ — $ — $ 24,699 $ — $ 1,591 $ 26,290 Ending balance: collectively evaluated for impairment $ 392,642 $ 104,344 $ 14,092 $ 1,508,728 $ 66,431 $ 31,912 $ 1,498 $ — $ 2,119,647 $ 30,498 $ 791,649 $ 2,941,794
Investment Of Originated Loans Held-For-Investment, Net Of Deferred Fees And Costs, By Loan Type And Credit Quality Indicator	The following table details the recorded investment of originated loans receivable held-for-investment, net of deferred fees and costs, by loan type and credit quality indicator at December 31, 2017 and 2016 (in thousands): At December 31, 2017 Real Estate Multifamily Commercial One-to-Four Family Construction and Land Home Equity and Lines of Credit Commercial and Industrial Other Total < 35% LTV => 35% LTV < 35% LTV => 35% LTV < 60% LTV => 60% LTV Internal Risk Rating Pass $ 131,792 $ 1,603,947 $ 84,620 $ 346,857 $ 60,400 $ 38,504 $ 34,620 $ 67,426 $ 34,141 $ 1,432 $ 2,403,739 Special Mention — 1,897 410 2,170 683 — — 28 571 — 5,759 Substandard — 1,584 — 11,724 1,470 593 — 225 181 — 15,777 Originated loans held-for-investment, net $ 131,792 $ 1,607,428 $ 85,030 $ 360,751 $ 62,553 $ 39,097 $ 34,620 $ 67,679 $ 34,893 $ 1,432 $ 2,425,275 At December 31, 2016 Real Estate Multifamily Commercial One-to-Four Family Construction and Land Home Equity and Lines of Credit Commercial and Industrial Other Total < 35% LTV => 35% LTV < 35% LTV => 35% LTV < 60% LTV => 60% LTV Internal Risk Rating Pass $ 122,525 $ 1,381,231 $ 65,612 $ 323,842 $ 59,214 $ 43,316 $ 14,092 $ 66,489 $ 31,173 $ 1,498 $ 2,108,992 Special Mention 25 4,636 — 3,852 705 — — 29 696 — 9,943 Substandard 40 1,643 1,179 18,867 1,807 1,482 — 249 144 — 25,411 Originated loans held-for-investment, net $ 122,590 $ 1,387,510 $ 66,791 $ 346,561 $ 61,726 $ 44,798 $ 14,092 $ 66,767 $ 32,013 $ 1,498 $ 2,144,346
Estimated Expected Future Cash Flows Of Each PCI Loan Pool	The following table sets forth the detail, and delinquency status, of originated and acquired non-performing loans (non-accrual loans and loans past due ninety days or more and still accruing), net of deferred fees and costs, at December 31, 2017 and 2016 (in thousands), excluding PCI loans which have been segregated into pools. For PCI loans, each loan pool is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. At December 31, 2017 Total Non-Performing Loans Non-Accruing Loans 0-29 Days Past Due 30-89 Days Past Due 90 Days or More Past Due Total 90 Days or More Past Due and Accruing Total Non-Performing Loans Loans held-for-investment: Real estate loans: Commercial LTV => 35% Substandard $ 432 $ 314 $ 2,305 $ 3,051 $ — $ 3,051 Total commercial 432 314 2,305 3,051 — 3,051 One-to-four family residential LTV < 60% Substandard — 206 328 534 — 534 LTV => 60% Substandard — — 39 39 — 39 Total one-to-four family residential — 206 367 573 — 573 Home equity and lines of credit Substandard 79 — — 79 — 79 Total home equity and lines of credit 79 — — 79 — 79 Commercial and industrial loans Substandard — — 72 72 — 72 Total commercial and industrial loans — — 72 72 — 72 Total non-performing loans held-for-investment 511 520 2,744 3,775 — 3,775 Loans acquired: Real Estate Loans: Commercial LTV < 35% Substandard — — 205 205 — 205 LTV => 35% Substandard — 773 58 831 — 831 Total Commercial — 773 263 1,036 — 1,036 One-to-four family residential LTV < 60% Substandard — 201 — 201 27 228 Total one-to-four family residential — 201 — 201 27 228 Multifamily LTV => 35% Substandard — 417 — 417 — 417 Total Multifamily — 417 — 417 — 417 Home equity and lines of credit Substandard — 28 49 77 — 77 Total home equity and lines of credit — 28 49 77 — 77 Commercial and industrial — — 2 2 — 2 Substandard Total commercial and industrial loans — — 2 2 — 2 Other loans Pass — — — — 1 1 Total other — — — — 1 1 Total non-performing loans acquired — 1,419 314 1,733 28 1,761 Total non-performing loans $ 511 $ 1,939 $ 3,058 $ 5,508 $ 28 $ 5,536 At December 31, 2016 Total Non-Performing Loans Non-Accruing Loans 0-29 Days Past Due 30-89 Days Past Due 90 Days or More Past Due Total 90 Days or More Past Due and Accruing Total Non-Performing Loans Loans held-for-investment: Real estate loans: Commercial LTV => 35% Substandard $ 341 $ — $ 4,882 $ 5,223 $ — $ 5,223 Total commercial 341 — 4,882 5,223 — 5,223 One-to-four family residential LTV < 60% Special Mention — — — — — Substandard 384 383 442 1,209 9 1,218 Total 384 383 442 1,209 9 1,218 LTV => 60% Substandard — — — — 43 43 Total — — — — 43 43 Total one-to-four family residential 384 383 442 1,209 52 1,261 Multifamily LTV < 35% Substandard 40 — — 40 — 40 LTV => 35% Substandard — — 3 3 — 3 Total multifamily 40 — 3 43 — 43 Home equity and lines of credit Substandard — 96 — 96 — 96 Total home equity and lines of credit — 96 — 96 — 96 Total non-performing loans held-for-investment 765 479 5,327 6,571 52 6,623 Loans acquired: Real estate loans: Commercial LTV < 35% Substandard — — 231 231 — 231 LTV => 35% Substandard — — 59 59 — 59 Total commercial — — 290 290 — 290 One-to-four family residential LTV < 60% Substandard 420 — — 420 — 420 Total one-to-four family residential 420 — — 420 — 420 Home equity and lines of credit Substandard — — 31 31 8 39 Total home equity and lines of credit — — 31 31 8 39 Commercial and industrial Substandard — — 9 9 — 9 Total commercial and industrial loans — — 9 9 — 9 Total non-performing loans acquired 420 — 330 750 8 758 Total non-performing loans $ 1,185 $ 479 $ 5,657 $ 7,321 $ 60 $ 7,381
Detail and Delinquency Status of Originated Loans Held-For-Investment, Net Of Deferred Fees and Costs, By Performing And Non-Performing Loans	The following table sets forth the detail and delinquency status of originated and acquired loans, net of deferred fees and costs, by performing and non-performing loans at December 31, 2017 and 2016 (in thousands): December 31, 2017 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Loans held-for-investment: Real estate loans: Commercial LTV < 35% Pass $ 84,620 $ — $ 84,620 $ — $ 84,620 Special Mention — 410 410 — 410 Total 84,620 410 85,030 — 85,030 LTV => 35% Pass 346,229 628 346,857 — 346,857 Special Mention 832 1,338 2,170 — 2,170 Substandard 7,675 998 8,673 3,051 11,724 Total 354,736 2,964 357,700 3,051 360,751 Total commercial 439,356 3,374 442,730 3,051 445,781 One-to-four family residential LTV < 60% Pass 57,907 2,493 60,400 — 60,400 Special Mention — 683 683 — 683 Substandard 322 614 936 534 1,470 Total 58,229 3,790 62,019 534 62,553 LTV => 60% Pass 38,504 — 38,504 — 38,504 Substandard 554 — 554 39 593 Total 39,058 — 39,058 39 39,097 Total one-to-four family residential 97,287 3,790 101,077 573 101,650 Construction and land Pass 34,614 6 34,620 — 34,620 Total construction and land 34,614 6 34,620 — 34,620 Multifamily LTV < 35% Pass 131,488 304 131,792 — 131,792 Total 131,488 304 131,792 — 131,792 LTV= > 35% Pass 1,603,714 233 1,603,947 — 1,603,947 Special Mention 638 1,259 1,897 — 1,897 Substandard 83 1,501 1,584 — 1,584 Total 1,604,435 2,993 1,607,428 — 1,607,428 Total multifamily 1,735,923 3,297 1,739,220 — 1,739,220 Home equity and lines of credit Pass 67,426 — 67,426 — 67,426 Special Mention 28 — 28 — 28 Substandard 146 — 146 79 225 Total home equity and lines of credit 67,600 — 67,600 79 67,679 Commercial and industrial loans Pass 34,003 138 34,141 — 34,141 Special Mention 547 24 571 — 571 Substandard 109 — 109 72 181 Total commercial and industrial loans 34,659 162 34,821 72 34,893 Other loans Pass 1,403 29 1,432 — 1,432 Total other loans 1,403 29 1,432 — 1,432 December 31, 2017 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Total originated loans held-for-investment 2,410,842 10,658 2,421,500 3,775 2,425,275 Acquired loans: One-to-four family residential LTV < 60% Pass 250,149 224 250,373 — 250,373 Special Mention 455 — 455 — 455 Substandard 417 150 567 228 795 Total 251,021 374 251,395 228 251,623 LTV => 60% Pass 23,295 — 23,295 — 23,295 Substandard 135 — 135 — 135 Total 23,430 — 23,430 — 23,430 Total one-to-four family residential 274,451 374 274,825 228 275,053 Commercial LTV < 35% Pass 50,035 70 50,105 — 50,105 Special Mention 91 — 91 — 91 Substandard — 181 181 205 386 Total 50,126 251 50,377 205 50,582 LTV => 35% Pass 108,125 158 108,283 — 108,283 Special Mention — 133 133 — 133 Substandard 3,703 430 4,133 831 4,964 Total 111,828 721 112,549 831 113,380 Total commercial 161,954 972 162,926 1,036 163,962 Construction and land Pass 17,201 — 17,201 — 17,201 Total construction and land 17,201 — 17,201 — 17,201 Multifamily LTV < 35% Pass 189,551 — 189,551 — 189,551 Special Mention 78 — 78 — 78 Substandard 153 — 153 — 153 Total 189,782 — 189,782 — 189,782 LTV => 35% Pass 8,950 — 8,950 — 8,950 Substandard — — — 417 417 Total 8,950 — 8,950 417 9,367 Total multifamily 198,732 — 198,732 417 199,149 Home equity and lines of credit Pass 20,291 — 20,291 — 20,291 Substandard 87 — 87 77 164 Total home equity and lines of credit 20,378 — 20,378 77 20,455 Commercial and industrial Pass 16,904 40 16,944 — 16,944 Substandard — — — 2 2 Total commercial and industrial 16,904 40 16,944 2 16,946 Other 36 — 36 1 37 Total loans acquired 689,656 1,386 691,042 1,761 692,803 $ 3,100,498 $ 12,044 $ 3,112,542 $ 5,536 $ 3,118,078 December 31, 2016 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Loans held-for-investment: Real estate loans: Commercial LTV < 35% Pass $ 65,189 $ 423 $ 65,612 $ — $ 65,612 Substandard 1,179 — 1,179 — 1,179 Total 66,368 423 66,791 — 66,791 LTV => 35% Pass 322,307 1,535 323,842 — 323,842 Special Mention 3,852 — 3,852 — 3,852 Substandard 12,600 1,044 13,644 5,223 18,867 Total 338,759 2,579 341,338 5,223 346,561 Total commercial 405,127 3,002 408,129 5,223 413,352 One-to-four family residential LTV < 60% Pass 56,787 2,427 59,214 — 59,214 Special Mention — 705 705 — 705 Substandard 589 — 589 1,218 1,807 Total 57,376 3,132 60,508 1,218 61,726 LTV => 60% Pass 43,316 — 43,316 — 43,316 Substandard 1,439 — 1,439 43 1,482 Total 44,755 — 44,755 43 44,798 Total one-to-four family residential 102,131 3,132 105,263 1,261 106,524 Construction and land Pass 14,092 — 14,092 — 14,092 Total construction and land 14,092 — 14,092 — 14,092 Multifamily LTV < 35% Pass 122,525 — 122,525 — 122,525 Special Mention 25 — 25 — 25 Substandard — — — 40 40 Total 122,550 — 122,550 40 122,590 LTV => 35% Pass 1,380,331 900 1,381,231 — 1,381,231 Special Mention 4,636 — 4,636 — 4,636 Substandard 1,640 — 1,640 3 1,643 Total 1,386,607 900 1,387,507 3 1,387,510 Total multifamily 1,509,157 900 1,510,057 43 1,510,100 Home equity and lines of credit Pass 66,369 120 66,489 — 66,489 Special Mention 29 — 29 — 29 Substandard 153 — 153 96 249 Total home equity and lines of credit 66,551 120 66,671 96 66,767 Commercial and industrial loans Pass 31,040 133 31,173 — 31,173 Special Mention 696 — 696 — 696 Substandard 144 — 144 — 144 Total Commercial and industrial loans 31,880 133 32,013 — 32,013 Other loans Pass 1,452 46 1,498 — 1,498 Total other loans 1,452 46 1,498 — 1,498 Total originated loans held-for-investment 2,130,390 7,333 2,137,723 6,623 2,144,346 December 31, 2016 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Loans acquired: One-to-four family residential LTV < 60% Pass 285,116 21 285,137 — 285,137 Special Mention 502 — 502 — 502 Substandard 654 261 915 420 1,335 Total 286,272 282 286,554 420 286,974 LTV => 60% Pass 30,199 — 30,199 — 30,199 Substandard 259 207 466 — 466 Total 30,458 207 30,665 — 30,665 Total one-to-four family residential 316,730 489 317,219 420 317,639 Commercial LTV < 35% Pass 61,646 7 61,653 — 61,653 Special Mention 286 — 286 — 286 Substandard 406 1,040 1,446 231 1,677 Total 62,338 1,047 63,385 231 63,616 LTV => 35% Pass 119,932 132 120,064 — 120,064 Special Mention 446 138 584 — 584 Substandard 3,419 259 3,678 59 3,737 Total 123,797 529 124,326 59 124,385 Total commercial 186,135 1,576 187,711 290 188,001 Construction and land Substandard 20,887 — 20,887 — 20,887 Total construction and land 20,887 — 20,887 — 20,887 Multifamily LTV < 35% Pass 205,025 — 205,025 — 205,025 Special Mention 99 111 210 — 210 Substandard 156 — 156 — 156 Total 205,280 111 205,391 — 205,391 LTV => 35% Pass 9,569 — 9,569 — 9,569 Special Mention — 429 429 — 429 Total 9,569 429 9,998 — 9,998 Total multifamily 214,849 540 215,389 — 215,389 Home equity and lines of credit Pass 25,340 45 25,385 — 25,385 Substandard — 98 98 39 137 Total home equity and lines of credit 25,340 143 25,483 39 25,522 Commercial and industrial loans Pass 25,419 — 25,419 — 25,419 Substandard — 15 15 9 24 Total Commercial and industrial loans 25,419 15 25,434 9 25,443 Other loans Pass 355 4 359 — 359 Total loans acquired 789,715 2,767 792,482 758 793,240 $ 2,920,105 $ 10,100 $ 2,930,205 $ 7,381 $ 2,937,586
Summary Of Impaired Loans	The following table summarizes the average recorded investment in originated and acquired impaired loans (excluding PCI loans) and interest recognized on impaired loans as of, and for, the years ended December 31, 2017 , and December 31, 2016 (in thousands): December 31, 2017 December 31, 2016 Average Recorded Investment Interest Income Average Recorded Investment Interest Income With No Allowance Recorded: Real estate loans: Commercial LTV < 35% Substandard $ — $ 45 $ — $ 39 LTV => 35% Pass 5,516 334 3,980 192 Special Mention — — — — Substandard 12,402 431 13,853 450 One-to-four family residential LTV < 60% Pass 854 56 559 31 Substandard 372 14 213 21 One-to-four family residential LTV => 60% Pass 55 4 — — Substandard 289 13 339 26 Multifamily LTV < 35% Substandard 154 6 62 6 LTV => 35% Pass 563 56 69 17 Substandard — — 582 — Home equity and lines of credit Pass 36 2 8 3 Commercial and industrial loans Substandard 127 — 81 — With a Related Allowance Recorded: Real estate loans: Commercial LTV => 35% Substandard 404 — 5,800 62 One-to-four family residential LTV < 60% Pass 165 7 137 — Special Mention — — — — Substandard 1,264 20 1,575 26 LTV => 60% Pass 271 19 110 6 Special Mention — — — — Substandard 152 — 796 4 Multifamily LTV => 35% Pass 778 — 794 50 Substandard 180 — 546 — Home equity and lines of credit December 31, 2017 December 31, 2016 Average Recorded Investment Interest Income Average Recorded Investment Interest Income Pass 153 — 264 8 Special Mention — — 34 — Substandard 37 1 40 1 Commercial and industrial loans Special Mention 25 1 27 1 Total: Real estate loans: Commercial 18,322 810 23,633 743 One-to-four family residential 3,422 133 3,729 114 Multifamily 1,675 62 2,053 73 Home equity and lines of credit 226 3 346 12 Commercial and industrial loans 152 1 108 1 $ 23,797 $ 1,009 $ 29,869 $ 943 The following table summarizes originated and acquired (subsequent to acquisition) impaired loans as of December 31, 2017 and 2016 (in thousands): At December 31, 2017 December 31, 2016 Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With No Allowance Recorded: Real estate loans: Commercial LTV < 35% Substandard $ — $ 139 $ — $ — $ 139 $ — LTV => 35% Pass 6,263 7,150 — 3,911 4,047 — Substandard 9,745 10,560 — 14,780 16,868 — One-to-four family residential LTV < 60% Pass 1,189 1,254 — 633 633 — Substandard 251 251 — 184 184 — LTV => 60% Pass 136 161 — — — — Substandard 135 286 — 620 848 — Multifamily LTV < 35% Substandard 153 153 — 156 156 — LTV => 35% Pass 1,309 1,780 — 63 534 — Home Equity Pass 33 33 — 39 39 — Commercial and industrial loans Substandard 135 135 — 75 75 — With a Related Allowance Recorded: Real estate loans: Commercial LTV => 35% Substandard — — — 2,019 2,019 (64 ) One-to-four family residential LTV < 60% Pass 411 411 (7 ) — — — Special Mention — — — — — — Substandard 997 997 (49 ) 1,522 1,522 (97 ) LTV => 60% Pass 268 268 (19 ) 275 275 (3 ) Substandard — — — 381 381 (41 ) Multifamily LTV => 35% Pass — — — 1,309 1,309 (95 ) Home equity and lines of credit Pass — — — 258 258 (5 ) Substandard 36 36 (4 ) 39 39 (18 ) Commercial and industrial loans Special Mention 24 24 (3 ) 26 26 (5 ) Total: Real estate loans: Commercial 16,008 17,849 — 20,710 23,073 (64 ) One-to-four family residential 3,387 3,628 (75 ) 3,615 3,843 (141 ) Construction and land — — — — — — Multifamily 1,462 1,933 — 1,528 1,999 (95 ) Home equity and lines of credit 69 69 (4 ) 336 336 (23 ) Commercial and industrial loans 159 $ 159 (3 ) 101 101 (5 ) $ 21,085 $ 23,638 $ (82 ) $ 26,290 $ 29,352 $ (328 )

Premises and Equipment, Net (Ta

Premises and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises And Equipment Less Accumulated Depreciation And Amortization	At December 31, 2017 and 2016 , premises and equipment, less accumulated depreciation and amortization, consists of the following (in thousands): December 31, 2017 2016 At cost: Land $ 4,018 $ 4,018 Buildings and improvements 8,883 8,856 Capital leases 2,600 2,600 Furniture, fixtures, and equipment 22,677 21,962 Leasehold improvements 28,721 27,398 66,899 64,834 Accumulated depreciation and amortization (41,153 ) (37,924 ) Premises and equipment, net $ 25,746 $ 26,910

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposit Account Balances	Deposit account balances are summarized as follows (dollars in thousands): As of December 31, 2017 2016 Amount Weighted Average Rate Amount Weighted Average Rate Transaction: Negotiable orders of withdrawal $ 465,140 0.39 % $ 467,440 0.34 % Non-interest bearing checking 407,267 — % 390,484 — % Total transaction 872,407 0.21 % 857,924 0.19 % Savings: Money market 800,854 0.72 % 818,660 0.67 % Savings 424,789 0.18 % 500,926 0.24 % Total savings 1,225,643 0.53 % 1,319,586 0.51 % Certificates of deposit: Under $100,000 401,063 1.42 % 484,480 1.22 % $100,000 or more 337,866 1.51 % 51,597 1.48 % Total certificates of deposit 738,929 1.46 % 536,077 1.24 % Total deposits $ 2,836,979 0.67 % $ 2,713,587 0.55 %
Maturities Of Certificates Of Deposit	Scheduled maturities of certificates of deposit are summarized as follows (in thousands): December 31, 2017 2018 $ 401,315 2019 157,397 2020 122,899 2021 23,511 2022 33,807 Thereafter — Total $ 738,929
Interest Expense On Deposits	Interest expense on deposits is summarized as follows (in thousands): December 31, 2017 2016 2015 Negotiable order of withdrawal and money market $ 7,336 $ 5,634 $ 2,816 Savings-passbook and statement 897 2,124 2,141 Certificates of deposit 8,153 6,529 5,466 $ 16,386 $ 14,287 $ 10,423

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary Of Borrowings	Borrowings consisted of securities sold under agreements to repurchase (repurchase agreements), FHLB advances, floating rate advances, and obligations under capital leases and are summarized as follows (in thousands): December 31, 2017 2016 Repurchase agreements $ 2,000 $ 8,000 Other borrowings: FHLB advances 464,217 453,220 Floating rate advances 5,033 11,463 Obligations under capital leases 299 523 $ 471,549 $ 473,206
Contractual Maturities Repurchase Agreements And FHLB Advances	Repurchase agreements and FHLB advances have contractual maturities as follows (in thousands): December 31, 2017 FHLB Repurchase Advances Agreements 2018 $ 160,715 $ 2,000 2019 123,502 — 2020 90,000 — 2021 70,000 — 2022 20,000 — $ 464,217 $ 2,000
Summary Of Interest Expense On Borrowings	Interest expense on borrowings is summarized as follows (in thousands): December 31, 2017 2016 2015 Repurchase agreements $ 137 $ 569 $ 2,446 FHLB advances 7,390 6,743 6,742 Floating rate advances 33 27 17 Obligations under capital leases 30 42 60 $ 7,590 $ 7,381 $ 9,265

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	Income tax expense (benefit) consists of the following (in thousands): December 31, 2017 2016 2015 Federal tax expense (benefit): Current $ 10,113 $ 14,218 $ 11,796 Deferred 14,290 (1,260 ) (2,305 ) 24,403 12,958 9,491 State and local tax expense (benefit): Current 1,672 2,506 1,811 Deferred 903 (1,799 ) 673 2,575 707 2,484 Total income tax expense $ 26,978 $ 13,665 $ 11,975
Reconciliation Between The Amount Of Reported Total Income Tax Expense And The Amount Computed By Multiplying The Applicable Statutory Income Tax Rate	Reconciliation between the amount of reported total income tax expense and the amount computed by multiplying the applicable statutory income tax rate for the years ended December 31, 2017 , 2016 , and 2015 , is as follows (dollars in thousands): December 31, 2017 2016 2015 Tax expense at statutory rate of 35% $ 18,111 $ 13,928 $ 11,027 Increase (decrease) in taxes resulting from: State tax, net of federal income tax 1,674 460 1,615 Impact of 2017 federal tax reform 10,453 — — Bank owned life insurance (1,885 ) (1,399 ) (1,319 ) ESOP fair market value adjustment 404 352 — Incentive stock options 247 299 210 Uncertain tax position 132 178 51 Merger related costs — 74 201 Excess tax benefits from employee share based payments (2,309 ) — — Other, net 151 (227 ) 190 Income tax expense $ 26,978 $ 13,665 $ 11,975
Tax Effects Of Temporary Differences That Give Rise To Significant Portions Of The Deferred Tax Assets And Deferred Tax Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2017 and 2016 , are as follows (in thousands): December 31, 2017 2016 Deferred tax assets: Allowance for loan losses $ 6,836 $ 9,470 Capitalized leases 84 213 Deferred compensation 3,474 5,686 Accrued salaries 2 1,128 Postretirement benefits 381 576 Equity awards 3,582 5,005 Unrealized actuarial losses on post-retirement benefits 93 124 Straight-line leases adjustment 892 1,219 Asset retirement obligation 65 89 Reserve for accrued interest receivable 712 1,116 Reserve for loan commitments 124 193 Employee Stock Ownership Plan 497 642 Other 236 366 Depreciation 2,116 2,509 Fair value adjustments of acquired loans 4,868 10,168 Fair value adjustments of pension benefit obligations 154 250 Unrealized losses on securities 2,070 2,775 Total gross deferred tax assets 26,186 41,529 Deferred tax liabilities: Fair value adjustments of acquired securities 35 82 Fair value adjustments of deposit liabilities 358 547 Deferred loan fees 1,815 1,910 Undistributed earnings related to NSB Realty Trust 939 — Other 37 59 Total gross deferred tax liabilities 3,184 2,598 Net deferred tax asset $ 23,002 $ 38,931
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the Company’s uncertain tax positions are as follows (in thousands): December 31, 2017 2016 2015 Beginning balance $ 459 $ 281 $ 230 Settlements based on tax positions related to prior years (109 ) — — Additions based on tax positions related to prior years 132 178 51 Ending balance $ 482 $ 459 $ 281

Retirement Benefits (Tables)

Retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Funded Status And Components Of Postretirement Benefit Costs	The following tables set forth the funded status and components of postretirement benefit costs at December 31 measurement dates (in thousands): 2017 2016 2015 Accumulated postretirement benefit obligation beginning of year $ 1,697 $ 1,950 $ 1,846 Service cost 11 8 9 Interest cost 57 71 62 Actuarial (gain) loss (8 ) (214 ) 149 Benefits paid (112 ) (118 ) (116 ) Accumulated postretirement benefit obligation end of year 1,645 1,697 1,950 Accrued liability (included in accrued expenses and other liabilities) $ 1,645 $ 1,697 $ 1,950
Amounts Recognized In Accumulated Other Comprehensive Income (Loss)	The following table sets forth the amounts recognized in accumulated other comprehensive income (loss) (in thousands): December 31, 2017 2016 Net loss $ 274 $ 310 Transition obligation — — Prior service cost — — Loss recognized in accumulated other comprehensive income (loss) $ 274 $ 310
Components Of Net Periodic Postretirement Benefit Cost	The following table sets forth the components of net periodic postretirement benefit costs for the years ended December 31, 2017 , 2016 , and 2015 (in thousands): December 31, 2017 2016 2015 Service cost $ 11 $ 8 $ 9 Interest cost 57 71 62 Amortization of transition obligation — — 17 Amortization of prior service costs — 12 38 Amortization of unrecognized loss 28 54 44 Net postretirement benefit cost included in compensation and employee benefits $ 96 $ 145 $ 170
Assumptions Used In Accounting For The Plan	The Company’s discount rate and rate of compensation increase used in accounting for the plan are as follows: 2017 2016 2015 Assumptions used to determine benefit obligation at period end: Discount rate 3.25 % 3.50 % 3.75 % Rate of increase in compensation 4.00 % 4.00 % 4.00 % Assumptions used to determine net periodic benefit cost for the year: Discount rate 3.50 % 3.75 % 3.50 % Rate of increase in compensation 4.00 % 4.00 % 4.00 %
Summary Of Percentage Point Change In Assumed Heath Care Cost Trends	A one percentage-point change in assumed heath care cost trends would have the following effects (in thousands): One Percentage Point Increase One Percentage Point Decrease 2017 2016 2017 2016 Effect on benefits earned and interest cost $ 4 $ 6 $ (4 ) $ (5 ) Effect on accumulated postretirement benefit obligation 111 121 (100 ) (108 ) A one percentage-point change in assumed heath care cost trends would have the following effects (in thousands): One Percentage Point Increase One Percentage Point Decrease 2017 2016 2015 2017 2016 2015 Aggregate of service and interest components of net periodic cost (benefit) $ 4 $ 6 $ 6 $ (4 ) $ (5 ) $ (4 )

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Valuation Assumptions	The fair value of stock options granted was estimated utilizing the Black-Scholes option pricing model using the following assumptions: Year Ended December 31, 2017 2016 Grant Date November 1, 2017 September 19, 2017 August 1, 2017 November 16, 2016 Stock options granted 40,000 12,500 45,744 40,000 Risk-free rate of return 2.06 % 1.89 % 1.86 % 1.8 % Volatility 29.22 % 30.06 % 29.46 % 30.07 % Dividend yield 2.37 % 1.98 % 1.91 % 1.74 % Expected life 5.75 5.75 5.75 6.5
Stock Options Outstanding	he following table is a summary of the Company’s non-vested stock options as of December 31, 2017 , and changes therein during the year then ended: Number of Stock Options Weighted Average Grant Date Fair Value Weighted Average Exercise Price Weighted Average Contractual Life (years) Outstanding- December 31, 2015 6,011,861 $ 3.30 $ 10.93 6.41 Granted 40,000 4.94 18.44 9.88 Forfeited (32,520 ) 4.00 13.78 — Exercised (690,671 ) 2.52 7.84 — Outstanding- December 31, 2016 5,328,670 3.41 11.36 5.78 Granted 98,244 4.04 16.73 9.71 Forfeited (247,484 ) 3.93 13.68 — Exercised (558,743 ) 2.41 7.52 — Outstanding - December 31, 2017 4,620,687 3.51 11.82 5.17 Exercisable - December 31, 2017 3,118,615 $ 3.25 $ 10.75 4.26
Status of the Company's Restricted Share Awards	The following is a summary of the status of the Company’s restricted shares as of December 31, 2017 , and changes therein during the year then ended: Number of Shares Awarded Weighted Average Grant Date Fair Value Non-vested at December 31, 2015 1,193,862 $ 13.70 Granted 20,000 18.44 Vested (277,580 ) 13.61 Forfeited (12,280 ) 13.87 Non-vested at December 31, 2016 924,002 13.82 Granted 34,500 16.70 Vested (279,660 ) 13.68 Forfeited (92,947 ) 13.92 Non-vested at December 31, 2017 585,895 $ 14.05

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitment And Contingent Liabilities Not Reflected In Consolidated Financial Statements	At December 31, 2017 and 2016 , the following commitment and contingent liabilities existed that are not reflected in the accompanying consolidated financial statements (in thousands): December 31, 2017 2016 Commitments to extend credit $ 43,611 $ 46,069 Unused lines of credit 98,433 78,825 Standby letters of credit 7,000 7,463
The Projected Minimum Annual Rental Payments And Receipts Under The Capitalized Leases And Operating Leases	The projected minimum annual rental payments and receipts under the capitalized leases and operating leases are as follows (in thousands): Rental Payments Capitalized Leases Rental Payments Operating Leases Year ending December 31: 2018 $ 262 $ 4,867 2019 44 5,167 2020 — 5,334 2021 — 4,885 2022 — 4,204 Thereafter — 35,748 Total minimum lease payments $ 306 $ 60,205

Regulatory Requirements (Tables

Regulatory Requirements (Tables)	12 Months Ended
	Dec. 31, 2017
Regulatory Requirements [Abstract]
Bank's Regulatory Capital Amounts And Ratios Compared To Regulatory Requirements	The following is a summary of Northfield Bank’s regulatory capital amounts and ratios compared to the regulatory requirements as of December 31, 2017 and 2016 , for classification as a well-capitalized institution and minimum capital (dollars in thousands): For Well For Capital Capitalized Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Common Equity Tier 1 Capital (to risk-weighted assets) $ 559,717 16.70 % $ 150,862 4.50 % $ 217,912 6.50 % Tier 1 Leverage 559,717 14.15 158,220 4.00 197,775 5.00 Tier I capital (to risk-weighted assets) 559,717 16.70 201,150 6.00 268,200 8.00 Total capital (to risk-weighted assets) 586,361 17.49 268,200 8.00 335,250 10.00 As of December 31, 2016: Common Equity Tier 1 Capital (to risk-weighted assets) $ 553,715 17.75 % $ 140,371 4.50 % $ 202,758 6.50 % Tier 1 Leverage 553,715 14.55 152,213 4.00 190,267 5.00 Tier I capital (to risk-weighted assets) 553,715 17.75 187,161 6.00 249,548 8.00 Total capital (to risk-weighted assets) 578,828 18.56 249,548 8.00 311,935 10.00 The following is a summary of the Company's regulatory capital amounts and ratios compared to the regulatory requirements as of December 31, 2017 and 2016 , for classification as a well-capitalized institution and minimum capital (dollars in thousands). For Well For Capital Capitalized Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio As of December 31, 2017: Common Equity Tier 1 Capital (to risk-weighted assets) $ 604,208 18.02 % $ 150,917 4.50 % $ 217,991 6.50 % Tier 1 Leverage 604,208 15.27 158,254 4.00 197,818 5.00 Tier I capital (to risk-weighted assets) 604,208 18.02 201,222 6.00 268,296 8.00 Total capital (to risk-weighted assets) 630,853 18.81 268,296 8.00 335,370 10.00 As of December 31, 2016: Common Equity Tier 1 Capital (to risk-weighted assets) $ 586,055 18.79 % $ 140,329 4.50 % $ 202,698 6.50 % Tier 1 Leverage 586,055 15.40 152,213 4.00 190,267 5.00 Tier I capital (to risk-weighted assets) 586,055 18.79 187,106 6.00 249,474 8.00 Total capital (to risk-weighted assets) 611,168 19.60 249,474 8.00 380,533 10.00

Fair Value of Measurement (Tabl

Fair Value of Measurement (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Significant Fair Value Of Assets And Liabilities Measured On Recurring And Non Recurring Basis	The following tables summarize financial assets and financial liabilities measured at fair value as of December 31, 2017 and 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands): Fair Value Measurements at December 31, 2017 Using: Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Measured on a recurring basis: Assets: Investment securities: Available-for-sale: Mortgage-backed securities GSE $ 445,224 $ — $ 445,224 $ — Non-GSE 79 — 79 — Debt securities Municipal bonds 349 — 349 Corporate bonds 68,130 — 68,130 — Other securities Equity investments - mutual funds 323 323 — — Other 1,016 — 1,016 — Total available-for-sale 515,121 323 514,798 — Trading securities 9,597 9,597 — — Total $ 524,718 $ 9,920 $ 514,798 $ — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 4,645 $ — $ — $ 4,645 One-to-four family residential mortgage 1,735 — — 1,735 Multifamily 51 — — 51 Home equity and lines of credit 31 — — 31 Total impaired real estate loans 6,462 — — 6,462 Commercial and industrial loans 21 — — 21 Other real estate owned 850 — — 850 Total $ 7,333 $ — $ — $ 7,333 Fair Value Measurements at December 31, 2016 Using: Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Measured on a recurring basis: Assets: Investment securities: Available-for-sale: Mortgage-backed securities GSE $ 448,842 $ — $ 448,842 $ — Non-GSE 270 — 270 — Debt securities Municipal Bonds 2,158 2,158 — Corporate bonds 45,159 45,159 — Other securities Equity investments - mutual funds 1,218 271 947 — Other 1,250 1,250 — Total available-for-sale 498,897 271 498,626 — Trading securities 7,857 7,857 — — Total $ 506,754 $ 8,128 $ 498,626 $ — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 10,730 $ — $ — $ 10,730 One-to-four family residential mortgage 2,177 — — 2,177 Multifamily 1,276 — — 1,276 Home equity and lines of credit 274 — — 274 Total impaired real estate loans 14,457 — — 14,457 Commercial and industrial loans 21 — — 21 Other real estate owned 850 — — 850 Total $ 15,328 $ — $ — $ 15,328
Level 3 Assets Measured At Fair Value On A Non-Recurring Basis	The following table presents qualitative information for Level 3 assets measured at fair value on a non-recurring basis at December 31, 2017 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 6,483 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 3.13% - 6.5% Other real estate owned $ 850 Appraisals Discount for costs to sell 7.0% The following table presents qualitative information for Level 3 assets measured at fair value on a non-recurring basis at December 31, 2016 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 14,478 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 4.75% - 7.5% Other real estate owned $ 850 Appraisals Discount for costs to sell 7.0%
Estimated Fair Values Of Significant Financial Instruments	The estimated fair values of the Company’s significant financial instruments at December 31, 2017 and 2016 , are presented in the following table (in thousands): December 31, 2017 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 57,839 $ 57,839 $ — $ — $ 57,839 Trading securities 9,597 9,597 — — 9,597 Securities available-for-sale 515,121 323 514,798 — 515,121 Securities held-to-maturity 9,931 — 9,892 — 9,892 FHLB of New York stock, at cost 25,046 — 25,046 — 25,046 Net loans held-for-investment 3,114,659 — — 3,157,829 3,157,829 Financial liabilities: Deposits $ 2,836,979 $ — $ 2,839,666 $ — $ 2,839,666 Repurchase agreements and other borrowings 471,549 — 466,625 — 466,625 Advance payments by borrowers 14,798 — 14,798 — 14,798 December 31, 2016 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 96,085 $ 96,085 $ — $ — $ 96,085 Trading securities 7,857 7,857 — — 7,857 Securities available-for-sale 498,897 271 498,626 — 498,897 Securities held-to-maturity 10,148 — 10,118 — 10,118 FHLB of New York stock, at cost 25,123 — 25,123 — 25,123 Net loans held-for-investment 2,943,489 — — 2,970,438 2,970,438 Financial liabilities: Deposits $ 2,713,587 $ — $ 2,720,176 $ — $ 2,720,176 Repurchase agreements and other borrowings 473,206 — 472,387 — 472,387 Advance payments by borrowers 12,331 — 12,331 — 12,331

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share Calculations And Reconciliation	The following is a summary of the Company’s earnings per share calculations and reconciliation of basic to diluted earnings per share for the periods indicated (in thousands, except share data): December 31, 2017 2016 2015 Net income available to common stockholders $ 24,768 $ 26,130 $ 19,531 Weighted average shares outstanding-basic 45,325,445 44,374,389 42,285,712 Effect of non-vested restricted stock and stock options outstanding 1,550,285 1,343,498 1,192,769 Weighted average shares outstanding-diluted 46,875,730 45,717,887 43,478,481 Earnings per share-basic $ 0.55 $ 0.59 $ 0.46 Earnings per share-diluted $ 0.53 $ 0.57 $ 0.45 Anti-dilutive shares 334,927 777,733 2,679,507

Parent-only Financial Informa40

Parent-only Financial Information (Tables) - Parent Company	12 Months Ended
	Dec. 31, 2017
Condensed Balance Sheets	Northfield Bancorp, Inc. Condensed Balance Sheets December 31, 2017 2016 (in thousands) Assets Cash in Northfield Bank $ 20,080 $ 8,953 Interest-earning deposits in other financial institutions 21 21 Investment in Northfield Bank 594,385 588,856 ESOP loan receivable 24,021 25,043 Other assets 1,185 118 Total assets $ 639,692 $ 622,991 Liabilities and Stockholders' Equity Total liabilities $ 815 $ 1,795 Total stockholders' equity 638,877 621,196 Total liabilities and stockholders' equity $ 639,692 $ 622,991
Condensed Statements of Comprehensive Income (Loss)	Northfield Bancorp, Inc. Condensed Statements of Comprehensive Income (Loss) Years Ended December 31, 2017 2016 2015 (in thousands) Interest on ESOP loan $ 939 $ 913 $ 875 Interest income on deposit in Northfield Bank 31 31 51 Gains (losses) on securities transactions, net 5 4 (4 ) Undistributed earnings of Northfield Bank 24,887 26,303 19,718 Total income 25,862 27,251 20,640 Other expenses 872 936 891 Income tax expense 222 185 218 Total expense 1,094 1,121 1,109 Net income $ 24,768 $ 26,130 $ 19,531 Comprehensive income: Net income $ 24,768 $ 26,130 $ 19,531 Other comprehensive loss, net of tax (227 ) (1,346 ) (2,221 ) Comprehensive income $ 24,541 $ 24,784 $ 17,310
Condensed Statements of Cash Flows	Northfield Bancorp, Inc. Condensed Statements of Cash Flows December 31, 2017 2016 2015 (in thousands) Cash flows from operating activities Net income $ 24,768 $ 26,130 $ 19,531 Adjustments to reconcile net income to net cash provided by operating activities: Increase in other assets (2,008 ) (1,994 ) (457 ) (Gains) losses on securities transactions, net (5 ) (4 ) 4 (Decrease) increase in other liabilities (980 ) 1,238 377 Undistributed earnings of Northfield Bank (24,887 ) (26,303 ) (19,718 ) Net cash used in operating activities (3,112 ) (933 ) (263 ) Cash flows from investing activities Cash consideration paid for business acquisition — (13,644 ) — Dividends from Northfield Bank 28,763 14,700 25,900 Net cash provided by investing activities 28,763 1,056 25,900 Cash flows from financing activities Principal payments on ESOP loan receivable 1,022 969 922 Purchase of treasury stock — (2,201 ) (48,446 ) Dividends paid (15,646 ) (14,074 ) (12,184 ) Exercise of stock options 100 120 158 Additional tax benefit on stock awards — 1,512 122 Net cash used in financing activities (14,524 ) (13,674 ) (59,428 ) Net increase (decrease) in cash and cash equivalents 11,127 (13,551 ) (33,791 ) Cash and cash equivalents at beginning of year 8,974 22,525 56,316 Cash and cash equivalents at end of year $ 20,101 $ 8,974 $ 22,525

Selected Quarterly Financial 41

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Parent Company
Selected Quarterly Financial Data (Unaudited)	The following tables are a summary of certain quarterly financial data for the years ended December 31, 2017 and 2016 : 2017 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 32,069 $ 32,660 $ 33,525 $ 34,615 Interest expense 5,392 5,751 6,173 6,660 Net interest income 26,677 26,909 27,352 27,955 Provision for loan losses 372 511 488 40 Net interest income after provision for loan losses 26,305 26,398 26,864 27,915 Other income 4,147 2,437 2,615 2,443 Other expenses 17,544 16,618 16,828 16,388 Income before income tax expense 12,908 12,217 12,651 13,970 Income tax expense 2,960 3,807 4,525 15,686 Net income (loss) $ 9,948 $ 8,410 $ 8,126 $ (1,716 ) Net income per basic common share $ 0.22 $ 0.19 $ 0.18 $ (0.04 ) Net income per diluted common share $ 0.21 $ 0.18 $ 0.17 $ (0.04 ) 2016 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 30,169 $ 31,168 $ 31,525 $ 32,110 Interest expense 5,441 5,527 5,274 5,426 Net interest income 24,728 25,641 26,251 26,684 Provision (recoveries) for loan losses (131 ) 14 472 280 Net interest income after provision for loan losses 24,859 25,627 25,779 26,404 Other income 2,229 2,533 2,667 2,643 Other expenses 21,499 17,494 17,377 16,576 Income before income tax expense 5,589 10,666 11,069 12,471 Income tax expense 1,929 3,681 3,782 4,273 Net income $ 3,660 $ 6,985 $ 7,287 $ 8,198 Net income per basic common share $ 0.08 $ 0.16 $ 0.16 $ 0.18 Net income per diluted common share $ 0.08 $ 0.15 $ 0.16 $ 0.18

Summary of Significant Accoun42

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Significant Accounting Policies [Line Items]
Delinquent status classification term	90 days
Threshold of membership investment component, percentage	0.125%
Threshold of membership investment component	$ 1
Activity based investment component as a percentage of outstanding advances	4.50%
Goodwill	$ 38,411	$ 38,411
ESOP repayment period (years)	30 years
Effect of non-vested restricted stock and stock options outstanding	1,550,285	1,343,498	1,192,769
Excess tax benefits from employee share based payments	$ 2,309
Accounting Standards Update 2016-09
Schedule Of Significant Accounting Policies [Line Items]
Cumulative effect of change in accounting principle - Adoption of ASU No. 2016-09		$ 0
Accounting Standards Update 2016-09 | Additional Paid-in Capital
Schedule Of Significant Accounting Policies [Line Items]
Cumulative effect of change in accounting principle - Adoption of ASU No. 2016-09		2,898
Accounting Standards Update 2016-09 | Retained Earnings
Schedule Of Significant Accounting Policies [Line Items]
Cumulative effect of change in accounting principle - Adoption of ASU No. 2016-09		$ (2,898)
Minimum
Schedule Of Significant Accounting Policies [Line Items]
Minimum amount of non-accrual loans individually evaluated for impairment	$ 500
Building
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful lives of significant classes of assets (years)	40 years
Furniture And Equipment | Minimum
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful lives of significant classes of assets (years)	5 years
Furniture And Equipment | Maximum
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful lives of significant classes of assets (years)	7 years
Software
Schedule Of Significant Accounting Policies [Line Items]
Estimated useful lives of significant classes of assets (years)	3 years

Business Combination - Narrativ

Business Combination - Narrative (Details) - Hopewell Valley Community Bank $ / shares in Units, $ in Thousands	Jan. 08, 2016USD ($)branch$ / sharesshares
Business Acquisition [Line Items]
Assets acquired	$ 508,455
Loans acquired	342,566
Deposits acquired	$ 456,203
Number of branch offices acquired | branch	9
Total consideration transferred	$ 55,400
Cash consideration	$ 13,700
Core Deposits
Business Acquisition [Line Items]
Estimated useful life	10 years
Common Stock
Business Acquisition [Line Items]
Consideration transferred, common stock (shares) | shares	2,707,381
Consideration transferred, common stock	$ 41,700
Closing price (usd per share) | $ / shares	$ 15.41

Business Combination - Fair Val

Business Combination - Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Jan. 08, 2016
ASSETS ACQUIRED:
Goodwill	$ 38,411	$ 38,411
Hopewell Valley Community Bank
ASSETS ACQUIRED:
Cash and cash equivalents, net			$ 55,479
Securities available for sale			61,633
Loans			342,566
Accrued interest receivable			1,452
Bank-owned life insurance			11,269
Premises and equipment			5,926
Federal Home Loan Bank of New York stock, at cost			476
Goodwill			22,252
Other intangible assets			2,013
Other assets			5,389
Total assets acquired			508,455
LIABILITIES ASSUMED:
Deposits			456,203
Other borrowings			2,213
Other liabilities			8,318
Total liabilities assumed			466,734
Net assets acquired			$ 41,721

Securities Available-for-Sale -

Securities Available-for-Sale - Comparative Summary Of Mortgage-Backed Securities And Other Securities Available-for-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 522,510	$ 505,834
Gross unrealized gains	2,123	3,222
Gross unrealized losses	9,512	10,159
Estimated fair value	515,121	498,897
Pass-through certificates | GSE
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	179,320	225,047
Gross unrealized gains	1,429	2,800
Gross unrealized losses	2,454	3,298
Estimated fair value	178,295	224,549
REMICs
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	452,901	455,827
Gross unrealized gains	1,716	3,059
Gross unrealized losses	9,314	9,774
Estimated fair value	445,303	449,112
REMICs | GSE
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	273,501	230,500
Gross unrealized gains	287	259
Gross unrealized losses	6,859	6,466
Estimated fair value	266,929	224,293
REMICs | Non-GSE
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	80	280
Gross unrealized gains	0	0
Gross unrealized losses	1	10
Estimated fair value	79	270
Debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	68,270	47,524
Gross unrealized gains	407	163
Gross unrealized losses	198	370
Estimated fair value	68,479	47,317
Debt securities | Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	343	2,151
Gross unrealized gains	6	13
Gross unrealized losses	0	6
Estimated fair value	349	2,158
Debt securities | Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	67,927	45,373
Gross unrealized gains	401	150
Gross unrealized losses	198	364
Estimated fair value	68,130	45,159
Other securities
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	1,339	2,483
Gross unrealized gains	0	0
Gross unrealized losses	0	15
Estimated fair value	1,339	2,468
Other securities | Equity investments - mutual funds
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	323	1,233
Gross unrealized gains	0	0
Gross unrealized losses	0	15
Estimated fair value	323	1,218
Other securities | Other
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	1,016	1,250
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Estimated fair value	$ 1,016	$ 1,250

Securities Available-for-Sale46

Securities Available-for-Sale - Summary Of Expected Maturity Distribution Of Debt Securities Available-For-Sale, Other Than Mortgage-Backed Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized cost	$ 522,510	$ 505,834
Estimated fair value	515,121	$ 498,897
Other Than Mortgage Backed Securities
Amortized cost, Due in one year or less	0
Amortized cost, Due after one year through five years	58,174
Amortized cost, Due after five years through ten years	10,096
Amortized cost	68,270
Estimated fair value, Due in one year or less	0
Estimated fair value, Due after one year through five years	58,285
Estimated fair value, Due after five years through ten years	10,194
Estimated fair value	$ 68,479

Securities Available-for-Sale47

Securities Available-for-Sale - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)security	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Schedule of Available-for-sale Securities [Line Items]
Carrying value of securities available-for-sale | $	$ 150,500	$ 108,800
Proceeds from sale of securities available-for-sale | $	5,941	44,582	$ 51,148
Gross realized gains on sales of securities available-for-sale | $	173	493	60
Gross realized losses on sales of securities available-for-sale | $	4	187	3
Gains on trading securities | $	$ 1,100	$ 507
Losses on trading securities | $			$ 396
Continuous Unrealized Loss Position Less Than 12 Months | REMIC
Schedule of Available-for-sale Securities [Line Items]
Number of securities	33
GSE | Continuous Unrealized Loss Position 12 Months Or Longer
Schedule of Available-for-sale Securities [Line Items]
Number of securities	33
GSE | Continuous Unrealized Loss Position 12 Months Or Longer | REMIC
Schedule of Available-for-sale Securities [Line Items]
Number of securities	19
GSE | Continuous Unrealized Loss Position Less Than 12 Months | Pass-through certificates
Schedule of Available-for-sale Securities [Line Items]
Number of securities	20
Non-GSE | Continuous Unrealized Loss Position 12 Months Or Longer | REMIC
Schedule of Available-for-sale Securities [Line Items]
Number of securities	1
Corporate bonds | Continuous Unrealized Loss Position Less Than 12 Months | REMIC
Schedule of Available-for-sale Securities [Line Items]
Number of securities	2
Municipal bonds | Continuous Unrealized Loss Position Less Than 12 Months | REMIC
Schedule of Available-for-sale Securities [Line Items]
Number of securities	3

Securities Available-for-Sale48

Securities Available-for-Sale - Gross Unrealized Losses On Mortgage-Backed Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	$ 1,433	$ 4,710
Estimated Fair value, less than 12 months	163,581	226,112
Unrealized losses, 12 months or more	8,079	5,449
Estimated Fair value, 12 months or more	231,106	106,398
Unrealized losses, total	9,512	10,159
Estimated fair value, total	394,687	332,510
Pass-through certificates | GSE
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	439	2,703
Estimated Fair value, less than 12 months	48,931	121,878
Unrealized losses, 12 months or more	2,015	595
Estimated Fair value, 12 months or more	76,113	8,402
Unrealized losses, total	2,454	3,298
Estimated fair value, total	125,044	130,280
REMICs | GSE
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	933	1,622
Estimated Fair value, less than 12 months	103,644	75,586
Unrealized losses, 12 months or more	5,926	4,844
Estimated Fair value, 12 months or more	139,830	97,726
Unrealized losses, total	6,859	6,466
Estimated fair value, total	243,474	173,312
REMICs | Non-GSE
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	0	0
Estimated Fair value, less than 12 months	0	0
Unrealized losses, 12 months or more	1	10
Estimated Fair value, 12 months or more	79	270
Unrealized losses, total	1	10
Estimated fair value, total	79	270
Debt securities
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		15
Estimated Fair value, less than 12 months		947
Unrealized losses, 12 months or more		0
Estimated Fair value, 12 months or more		0
Unrealized losses, total		15
Estimated fair value, total		947
Debt securities | Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months		6
Estimated Fair value, less than 12 months		1,679
Unrealized losses, 12 months or more		0
Estimated Fair value, 12 months or more		0
Unrealized losses, total		6
Estimated fair value, total		1,679
Debt securities | Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, less than 12 months	61	364
Estimated Fair value, less than 12 months	11,006	26,022
Unrealized losses, 12 months or more	137	0
Estimated Fair value, 12 months or more	15,084	0
Unrealized losses, total	198	364
Estimated fair value, total	$ 26,090	$ 26,022

Securities Held-to-Maturity (De

Securities Held-to-Maturity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 9,931,000	$ 10,148,000
Gross Unrealized Gains	17,000	29,000
Gross Unrealized Losses	56,000	59,000
Securities held-to-maturity	9,892,000	10,118,000
Sales of held-to-maturity securities	0	0	$ 0
Other-than-temporary impairment charges	0	0	$ 0
Held-to-maturity securities pledged to secured repurchase agreements and deposits	2,800,000	5,000,000
Mortgage-Backed Securities, Pass-Through Certificates
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	9,931,000	10,148,000
Gross Unrealized Gains	17,000	29,000
Gross Unrealized Losses	56,000	59,000
Securities held-to-maturity	$ 9,892,000	$ 10,118,000

Securities Held-to-Maturity - U

Securities Held-to-Maturity - Unrealized Losses and Estimated Fair Value (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)security	Dec. 31, 2016USD ($)
Unrealized Losses
Less than 12 months	$ 7	$ 59
12 months or more	49
Total	56
Fair Value
Less than 12 months	3,922	7,466
12 months or more	3,735
Total	7,657
Mortgage-Backed Securities, Pass-Through Certificates
Unrealized Losses
Less than 12 months	7	59
12 months or more	49
Total	56
Fair Value
Less than 12 months	3,922	$ 7,466
12 months or more	3,735
Total	$ 7,657
Number of held-to-maturity securities in an unrealized loss position, greater than twelve months | security	2
Number of held-to-maturity securities in an unrealized loss position, less than twelve months | security	3

Loans - Net Loans Held-For-Inve

Loans - Net Loans Held-For-Investment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investments In Loans [Line Items]
Commercial and industrial loans	$ 34,828	$ 31,906
Other loans	1,430	1,497
Deferred loan cost, net	6,339	6,471
Originated loans held-for-investment, net	2,425,275	2,144,346
PCI Loans	22,741	30,498
Loans acquired	692,803	793,240
Loans held-for-investment, net	3,140,819	2,968,084
Allowance for loan losses	(26,160)	(24,595)	$ (24,770)	$ (26,292)
Net loans held-for-investment	3,114,659	2,943,489
Real Estate Loans
Investments In Loans [Line Items]
Loans receivable	2,382,678	2,104,472
Real Estate Loans | Multifamily
Investments In Loans [Line Items]
Loans receivable	1,735,712	1,506,335
Loans held-for-investment, net	1,739,220	1,510,100
Allowance for loan losses	(17,374)	(14,952)	(12,387)
Real Estate Loans | Commercial mortgage
Investments In Loans [Line Items]
Loans receivable	445,225	412,667
Loans held-for-investment, net	445,781	413,352
Allowance for loan losses	(5,196)	(5,432)	(7,106)
Real Estate Loans | One-to-four family residential mortgage
Investments In Loans [Line Items]
Loans receivable	100,942	105,968
Loans held-for-investment, net	101,650	106,524
Allowance for loan losses	(503)	(664)	(787)
Real Estate Loans | Home equity and lines of credit
Investments In Loans [Line Items]
Loans receivable	66,254	65,437
Loans held-for-investment, net	67,679	66,767
Allowance for loan losses	(122)	(588)	(795)
Real Estate Loans | Construction and land
Investments In Loans [Line Items]
Loans receivable	34,545	14,065
Loans held-for-investment, net	34,620	14,092
Allowance for loan losses	(610)	(172)	$ (261)
Real Estate Loans Acquired
Investments In Loans [Line Items]
Loans acquired	675,820	767,438
Real Estate Loans Acquired | Multifamily
Investments In Loans [Line Items]
Loans acquired	199,149	215,389
Real Estate Loans Acquired | Commercial mortgage
Investments In Loans [Line Items]
Loans acquired	163,962	188,001
Real Estate Loans Acquired | One-to-four family residential mortgage
Investments In Loans [Line Items]
Loans acquired	275,053	317,639
Real Estate Loans Acquired | Home equity and lines of credit
Investments In Loans [Line Items]
Loans acquired	20,455	25,522
Real Estate Loans Acquired | Construction and land
Investments In Loans [Line Items]
Loans acquired	17,201	20,887
Acquired Loans
Investments In Loans [Line Items]
Commercial and industrial loans	16,946	25,443
Other loans	37	359
Loans acquired	$ 692,803	$ 793,240

Loans - Narrative, PCI Loans (D

Loans - Narrative, PCI Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of loans held for sale	$ 0	$ 0
Purchased credit-impaired (PCI) loans held-for-investment	$ 22,741,000	30,498,000
Purchased credit-impaired (PCI) loans held-for-investment, Federal Deposit Insurance Corporation assisted transaction		$ 30,500,000
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased credit-impaired (PCI) loan percent	27.00%	30.00%
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased credit-impaired (PCI) loan percent	50.00%	48.00%

Loans - PCI Loans Acquired from

Loans - PCI Loans Acquired from Hopewell Valley (Details) - Hopewell Valley Community Bank $ in Thousands	Jan. 08, 2016USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required principal and interest at acquisition	$ 16,580
Contractual cash flows not expected to be collected (non-accretable discount)	(9,929)
Expected cash flows to be collected at acquisition	6,651
Interest component of expected cash flows (accretable discount)	(845)
Fair value of acquired loans	$ 5,806

Loans - Summary Of Accretable Y

Loans - Summary Of Accretable Yield (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at the beginning of year	$ 24,215	$ 22,853
Acquisition	0	845
Accretion into interest income	(5,477)	(5,225)
Net reclassification from non-accretable difference	5,764	5,742
Balance at end of year	$ 24,502	$ 24,215

Loans - Activity In The Allowan

Loans - Activity In The Allowance For Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan and Lease Losses
Beginning Balance	$ 24,595	$ 24,770	$ 26,292
Provision for loan losses	1,411	635	353
Recoveries	556	194	140
Charge-offs	(402)	(1,004)	(2,015)
Ending Balance	$ 26,160	$ 24,595	$ 24,770

Loans - Allowance For Loan Loss

Loans - Allowance For Loan Losses And The Loans Receivable By Portfolio Segment And Based On Impairment Method (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for loan losses:
Beginning Balance	$ 24,595	$ 24,770	$ 26,292
Charge-offs	(402)	(1,004)	(2,015)
Recoveries	556	194	140
Provisions (credit)	1,411	635	353
Ending Balance	26,160	24,595	24,770
Ending balance: individually evaluated for impairment	82	328
Ending balance: collectively evaluated for impairment	26,078	24,267
Loans, net:
Loans held-for-investment, net	3,140,819	2,968,084
Ending balance: individually evaluated for impairment	21,085	26,290
Ending balance: collectively evaluated for impairment	3,119,734	2,941,794
Commercial and Industrial
Allowance for loan losses:
Beginning Balance	1,720	1,288
Charge-offs	(73)	(66)
Recoveries	79	4
Provisions (credit)	(453)	494
Ending Balance	1,273	1,720	1,288
Ending balance: individually evaluated for impairment	3	5
Ending balance: collectively evaluated for impairment	1,270	1,715
Loans, net:
Loans held-for-investment, net	34,893	32,013
Ending balance: individually evaluated for impairment	159	101
Ending balance: collectively evaluated for impairment	34,734	31,912
Other
Allowance for loan losses:
Beginning Balance	96	155
Charge-offs	0	(2)
Recoveries	0	5
Provisions (credit)	(2)	(62)
Ending Balance	94	96	155
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	94	96
Loans, net:
Loans held-for-investment, net	1,432	1,498
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	1,432	1,498
Unallocated
Allowance for loan losses:
Beginning Balance	0	1,093
Charge-offs	0	0
Recoveries	0	0
Provisions (credit)	0	(1,093)
Ending Balance	0	0	1,093
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	0	0
Loans, net:
Loans held-for-investment, net	0	0
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	0	0
Originated Loans Total
Allowance for loan losses:
Beginning Balance	23,624	23,872
Charge-offs	(365)	(1,004)
Recoveries	523	194
Provisions (credit)	1,390	562
Ending Balance	25,172	23,624	23,872
Ending balance: individually evaluated for impairment	45	253
Ending balance: collectively evaluated for impairment	25,127	23,371
Loans, net:
Loans held-for-investment, net	2,425,275	2,144,346
Ending balance: individually evaluated for impairment	19,542	24,699
Ending balance: collectively evaluated for impairment	2,405,733	2,119,647
PCI
Allowance for loan losses:
Beginning Balance	896	783
Charge-offs	0	0
Recoveries	0	0
Provisions (credit)	55	113
Ending Balance	951	896	783
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	951	896
Loans, net:
Loans held-for-investment, net	22,741	30,498
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	22,741	30,498
Acquired Loans
Allowance for loan losses:
Beginning Balance	75	115
Charge-offs	(37)	0
Recoveries	33	0
Provisions (credit)	(34)	(40)
Ending Balance	37	75	115
Ending balance: individually evaluated for impairment	37	75
Ending balance: collectively evaluated for impairment	0	0
Loans, net:
Loans held-for-investment, net	692,803	793,240
Ending balance: individually evaluated for impairment	1,543	1,591
Ending balance: collectively evaluated for impairment	691,260	791,649
Real Estate Loans | Commercial mortgage
Allowance for loan losses:
Beginning Balance	5,432	7,106
Charge-offs	(4)	(638)
Recoveries	70	181
Provisions (credit)	(302)	(1,217)
Ending Balance	5,196	5,432	7,106
Ending balance: individually evaluated for impairment	0	64
Ending balance: collectively evaluated for impairment	5,196	5,368
Loans, net:
Loans held-for-investment, net	445,781	413,352
Ending balance: individually evaluated for impairment	16,008	20,710
Ending balance: collectively evaluated for impairment	429,773	392,642
Real Estate Loans | One-to-four family residential mortgage
Allowance for loan losses:
Beginning Balance	664	787
Charge-offs	0	(20)
Recoveries	0	2
Provisions (credit)	(161)	(105)
Ending Balance	503	664	787
Ending balance: individually evaluated for impairment	38	66
Ending balance: collectively evaluated for impairment	465	598
Loans, net:
Loans held-for-investment, net	101,650	106,524
Ending balance: individually evaluated for impairment	1,996	2,180
Ending balance: collectively evaluated for impairment	99,654	104,344
Real Estate Loans | Construction and land
Allowance for loan losses:
Beginning Balance	172	261
Charge-offs	0	0
Recoveries	0	0
Provisions (credit)	438	(89)
Ending Balance	610	172	261
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	610	172
Loans, net:
Loans held-for-investment, net	34,620	14,092
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	34,620	14,092
Real Estate Loans | Multifamily
Allowance for loan losses:
Beginning Balance	14,952	12,387
Charge-offs	(184)	(278)
Recoveries	277	0
Provisions (credit)	2,329	2,843
Ending Balance	17,374	14,952	12,387
Ending balance: individually evaluated for impairment	0	95
Ending balance: collectively evaluated for impairment	17,374	14,857
Loans, net:
Loans held-for-investment, net	1,739,220	1,510,100
Ending balance: individually evaluated for impairment	1,310	1,372
Ending balance: collectively evaluated for impairment	1,737,910	1,508,728
Real Estate Loans | Home equity and lines of credit
Allowance for loan losses:
Beginning Balance	588	795
Charge-offs	(104)	0
Recoveries	97	2
Provisions (credit)	(459)	(209)
Ending Balance	122	588	$ 795
Ending balance: individually evaluated for impairment	4	23
Ending balance: collectively evaluated for impairment	118	565
Loans, net:
Loans held-for-investment, net	67,679	66,767
Ending balance: individually evaluated for impairment	69	336
Ending balance: collectively evaluated for impairment	$ 67,610	$ 66,431

Loans - Narrative, Loan-to-Valu

Loans - Narrative, Loan-to-Value Ratios (Details)	Dec. 31, 2017
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan to value ratio, less than	35.00%
One-to-four family residential mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan to value ratio, less than	60.00%

Loans - Investment Of Originate

Loans - Investment Of Originated Loans Held-For-Investment, Net Of Deferred Fees And Costs, By Loan Type And Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	$ 2,425,275	$ 2,144,346
Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	2,403,739	2,108,992
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	5,759	9,943
Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	15,777	25,411
Multifamily | Real Estate Loans | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	131,792	122,590
Multifamily | Real Estate Loans | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,607,428	1,387,510
Multifamily | Real Estate Loans | Pass | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	131,792	122,525
Multifamily | Real Estate Loans | Pass | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,603,947	1,381,231
Multifamily | Real Estate Loans | Special Mention | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	25
Multifamily | Real Estate Loans | Special Mention | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,897	4,636
Multifamily | Real Estate Loans | Substandard | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	40
Multifamily | Real Estate Loans | Substandard | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,584	1,643
Commercial mortgage | Real Estate Loans | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	85,030	66,791
Commercial mortgage | Real Estate Loans | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	360,751	346,561
Commercial mortgage | Real Estate Loans | Pass | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	84,620	65,612
Commercial mortgage | Real Estate Loans | Pass | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	346,857	323,842
Commercial mortgage | Real Estate Loans | Special Mention | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	410	0
Commercial mortgage | Real Estate Loans | Special Mention | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	2,170	3,852
Commercial mortgage | Real Estate Loans | Substandard | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	1,179
Commercial mortgage | Real Estate Loans | Substandard | Greater Than or Equal to 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	11,724	18,867
One-to-four family residential mortgage | Real Estate Loans | Less Than 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	62,553	61,726
One-to-four family residential mortgage | Real Estate Loans | Greater than or Equal to 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	39,097	44,798
One-to-four family residential mortgage | Real Estate Loans | Pass | Less Than 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	60,400	59,214
One-to-four family residential mortgage | Real Estate Loans | Pass | Greater than or Equal to 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	38,504	43,316
One-to-four family residential mortgage | Real Estate Loans | Special Mention | Less Than 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	683	705
One-to-four family residential mortgage | Real Estate Loans | Special Mention | Greater than or Equal to 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
One-to-four family residential mortgage | Real Estate Loans | Substandard | Less Than 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,470	1,807
One-to-four family residential mortgage | Real Estate Loans | Substandard | Greater than or Equal to 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	593	1,482
Construction and land | Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	34,620	14,092
Construction and land | Real Estate Loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	34,620	14,092
Construction and land | Real Estate Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Construction and land | Real Estate Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Home equity and lines of credit | Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	67,679	66,767
Home equity and lines of credit | Real Estate Loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	67,426	66,489
Home equity and lines of credit | Real Estate Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	28	29
Home equity and lines of credit | Real Estate Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	225	249
Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	34,893	32,013
Commercial and Industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	34,141	31,173
Commercial and Industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	571	696
Commercial and Industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	181	144
Other loans
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,432	1,498
Other loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,432	1,498
Other loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Other loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	$ 0	$ 0

Loans - Narrative, Loans (Detai

Loans - Narrative, Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment in non accrual loans	$ 5,500,000	$ 7,300,000
Delinquent status classification term	90 days
Impairment of loans	$ 3,100,000	5,700,000
Principal balance of loans on non accrual status	2,400,000	1,700,000
Loans held-for-sale non accrual amount	0	0
Loans past 90 days and still accruing	28,000	$ 60,000
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance of loans on non accrual status	$ 500,000

Loans - Estimated Expected Futu

Loans - Estimated Expected Future Cash Flows Of Each PCI Loan Pool (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or More Past Due and Accruing	$ 28	$ 60
Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	5,508	7,321
90 Days or More Past Due and Accruing	28	60
Total Non-Performing Loans	5,536	7,381
Non-Performing Loans | Loans Held For Investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,775	6,571
90 Days or More Past Due and Accruing	0	52
Total Non-Performing Loans	3,775	6,623
Non-Performing Loans | Loans Held For Investment | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,051	5,223
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	3,051	5,223
Non-Performing Loans | Loans Held For Investment | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,051	5,223
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	3,051	5,223
Non-Performing Loans | Loans Held For Investment | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	573	1,209
90 Days or More Past Due and Accruing	0	52
Total Non-Performing Loans	573	1,261
Non-Performing Loans | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		1,209
90 Days or More Past Due and Accruing		9
Total Non-Performing Loans		1,218
Non-Performing Loans | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	534	1,209
90 Days or More Past Due and Accruing	0	9
Total Non-Performing Loans	534	1,218
Non-Performing Loans | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
90 Days or More Past Due and Accruing
Total Non-Performing Loans		0
Non-Performing Loans | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
90 Days or More Past Due and Accruing		43
Total Non-Performing Loans		43
Non-Performing Loans | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	39	0
90 Days or More Past Due and Accruing	0	43
Total Non-Performing Loans	39	43
Non-Performing Loans | Loans Held For Investment | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		43
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		43
Non-Performing Loans | Loans Held For Investment | Multifamily | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		40
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		40
Non-Performing Loans | Loans Held For Investment | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		3
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		3
Non-Performing Loans | Loans Held For Investment | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	79	96
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	79	96
Non-Performing Loans | Loans Held For Investment | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	79	96
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	79	96
Non-Performing Loans | Loans Held For Investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	72
90 Days or More Past Due and Accruing	0
Total Non-Performing Loans	72
Non-Performing Loans | Loans Held For Investment | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	72
90 Days or More Past Due and Accruing	0
Total Non-Performing Loans	72
Non-Performing Loans | Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	1,733	750
90 Days or More Past Due and Accruing	28	8
Total Non-Performing Loans	1,761	758
Non-Performing Loans | Acquired Loans | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	1,036
90 Days or More Past Due and Accruing	0
Total Non-Performing Loans	1,036
Non-Performing Loans | Acquired Loans | Commercial mortgage | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	205	231
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	205	231
Non-Performing Loans | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		290
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		290
Non-Performing Loans | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	831	59
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	831	59
Non-Performing Loans | Acquired Loans | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	201	420
90 Days or More Past Due and Accruing	27	0
Total Non-Performing Loans	228	420
Non-Performing Loans | Acquired Loans | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	201	420
90 Days or More Past Due and Accruing	27	0
Total Non-Performing Loans	228	420
Non-Performing Loans | Acquired Loans | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	417
90 Days or More Past Due and Accruing	0
Total Non-Performing Loans	417
Non-Performing Loans | Acquired Loans | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	417
90 Days or More Past Due and Accruing	0
Total Non-Performing Loans	417
Non-Performing Loans | Acquired Loans | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	77	31
90 Days or More Past Due and Accruing	0	8
Total Non-Performing Loans	77	39
Non-Performing Loans | Acquired Loans | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	77	31
90 Days or More Past Due and Accruing	0	8
Total Non-Performing Loans	77	39
Non-Performing Loans | Acquired Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2	9
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	2	9
Non-Performing Loans | Acquired Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		9
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		9
Non-Performing Loans | Acquired Loans | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
90 Days or More Past Due and Accruing	1
Total Non-Performing Loans	1
Non-Performing Loans | 0-29 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	511	1,185
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	511	765
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	432	341
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	432	341
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	384
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		384
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	384
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		40
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Multifamily | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		40
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	79	0
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	79	0
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 0-29 Days Past Due | Loans Held For Investment | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	420
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Commercial mortgage | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	420
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	420
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 0-29 Days Past Due | Acquired Loans | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	1,939	479
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	520	479
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	314	0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	314	0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	206	383
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		383
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	206	383
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Multifamily | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	96
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	96
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 30-89 Days Past Due | Loans Held For Investment | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	1,419	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	773
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Commercial mortgage | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	773	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	201	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	201	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	417
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	417
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	28	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	28	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 30-89 Days Past Due | Acquired Loans | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,058	5,657
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,744	5,327
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,305	4,882
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,305	4,882
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	367	442
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		442
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	328	442
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	39	0
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		3
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Multifamily | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		3
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	72
Non-Performing Loans | 90 Days or More Past Due | Loans Held For Investment | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	72
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	314	330
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	263
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Commercial mortgage | Less Than 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	205	231
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		290
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	58	59
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Multifamily | Greater Than or Equal to 35% LTV | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	49	31
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	49	31
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2	9
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		$ 9
Non-Performing Loans | 90 Days or More Past Due | Acquired Loans | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	$ 0

Loans - Detail And Delinquency

Loans - Detail And Delinquency Status Of Originated Loans Held-For-Investment, Net Of Deferred Fees And Costs, By Performing And Non-Performing Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	$ 2,425,275	$ 2,144,346
Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	5,508	7,321
Non-Performing Loans	5,536	7,381
Loans Held For Investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	2,425,275	2,144,346
Loans Held For Investment | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,421,500	2,137,723
Loans Held For Investment | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	3,775	6,623
Loans Held For Investment | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	445,781	413,352
Loans Held For Investment | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	85,030	66,791
Loans Held For Investment | Commercial mortgage | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	360,751	346,561
Loans Held For Investment | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	84,620	65,612
Loans Held For Investment | Commercial mortgage | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	346,857	323,842
Loans Held For Investment | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	410
Loans Held For Investment | Commercial mortgage | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	2,170	3,852
Loans Held For Investment | Commercial mortgage | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net		1,179
Loans Held For Investment | Commercial mortgage | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	11,724	18,867
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	442,730	408,129
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	85,030	66,791
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	357,700	341,338
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	84,620	65,612
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	346,857	323,842
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	410
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,170	3,852
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		1,179
Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,673	13,644
Loans Held For Investment | Commercial mortgage | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	3,051	5,223
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	3,051	5,223
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Loans Held For Investment | Commercial mortgage | Non-Performing Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	3,051	5,223
Loans Held For Investment | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	101,650	106,524
Loans Held For Investment | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	62,553	61,726
Loans Held For Investment | One-to-four family residential mortgage | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	39,097	44,798
Loans Held For Investment | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	60,400	59,214
Loans Held For Investment | One-to-four family residential mortgage | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	38,504	43,316
Loans Held For Investment | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	683	705
Loans Held For Investment | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,470	1,807
Loans Held For Investment | One-to-four family residential mortgage | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	593	1,482
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	101,077	105,263
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	62,019	60,508
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	39,058	44,755
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	60,400	59,214
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	38,504	43,316
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	683	705
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	936	589
Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	554	1,439
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	573	1,261
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	534	1,218
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	39	43
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	534	1,218
Loans Held For Investment | One-to-four family residential mortgage | Non-Performing Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	39	43
Loans Held For Investment | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	34,620	14,092
Loans Held For Investment | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	34,620	14,092
Loans Held For Investment | Construction and land | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,620	14,092
Loans Held For Investment | Construction and land | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,620	14,092
Loans Held For Investment | Construction and land | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Construction and land | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,739,220	1,510,100
Loans Held For Investment | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	131,792	122,590
Loans Held For Investment | Multifamily | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,607,428	1,387,510
Loans Held For Investment | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	131,792	122,525
Loans Held For Investment | Multifamily | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,603,947	1,381,231
Loans Held For Investment | Multifamily | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net		25
Loans Held For Investment | Multifamily | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,897	4,636
Loans Held For Investment | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net		40
Loans Held For Investment | Multifamily | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,584	1,643
Loans Held For Investment | Multifamily | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,739,220	1,510,057
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	131,792	122,550
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,607,428	1,387,507
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	131,792	122,525
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,603,947	1,381,231
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		25
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,897	4,636
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,584	1,640
Loans Held For Investment | Multifamily | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	43
Loans Held For Investment | Multifamily | Non-Performing Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	40
Loans Held For Investment | Multifamily | Non-Performing Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	3
Loans Held For Investment | Multifamily | Non-Performing Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Multifamily | Non-Performing Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Multifamily | Non-Performing Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Loans Held For Investment | Multifamily | Non-Performing Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Multifamily | Non-Performing Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		40
Loans Held For Investment | Multifamily | Non-Performing Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	3
Loans Held For Investment | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	67,679	66,767
Loans Held For Investment | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	67,426	66,489
Loans Held For Investment | Home equity and lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	28	29
Loans Held For Investment | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	225	249
Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	67,600	66,671
Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	67,426	66,489
Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	28	29
Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	146	153
Loans Held For Investment | Home equity and lines of credit | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	79	96
Loans Held For Investment | Home equity and lines of credit | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Home equity and lines of credit | Non-Performing Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Home equity and lines of credit | Non-Performing Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	79	96
Loans Held For Investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	34,893	32,013
Loans Held For Investment | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	34,141	31,173
Loans Held For Investment | Commercial and Industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	571	696
Loans Held For Investment | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	181	144
Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,821	32,013
Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,141	31,173
Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	571	696
Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	109	144
Loans Held For Investment | Commercial and Industrial | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	72	0
Loans Held For Investment | Commercial and Industrial | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Commercial and Industrial | Non-Performing Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Commercial and Industrial | Non-Performing Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	72	0
Loans Held For Investment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,432	1,498
Loans Held For Investment | Other loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	1,432	1,498
Loans Held For Investment | Other loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,432	1,498
Loans Held For Investment | Other loans | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,432	1,498
Loans Held For Investment | Other loans | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans Held For Investment | Other loans | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	692,803	793,240
Acquired Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	691,042	792,482
Acquired Loans | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	1,761	758
Acquired Loans | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	163,962	188,001
Acquired Loans | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	50,582	63,616
Acquired Loans | Commercial mortgage | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	113,380	124,385
Acquired Loans | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	50,105	61,653
Acquired Loans | Commercial mortgage | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	108,283	120,064
Acquired Loans | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	91	286
Acquired Loans | Commercial mortgage | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	133	584
Acquired Loans | Commercial mortgage | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	386	1,677
Acquired Loans | Commercial mortgage | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	4,964	3,737
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	162,926	187,711
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	50,377	63,385
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	112,549	124,326
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	50,105	61,653
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	108,283	120,064
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	91	286
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	133	584
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	181	1,446
Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	4,133	3,678
Acquired Loans | Commercial mortgage | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	1,036	290
Acquired Loans | Commercial mortgage | Non-Performing Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	205	231
Acquired Loans | Commercial mortgage | Non-Performing Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	831	59
Acquired Loans | Commercial mortgage | Non-Performing Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Commercial mortgage | Non-Performing Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Commercial mortgage | Non-Performing Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Commercial mortgage | Non-Performing Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Commercial mortgage | Non-Performing Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	205	231
Acquired Loans | Commercial mortgage | Non-Performing Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	831	59
Acquired Loans | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	275,053	317,639
Acquired Loans | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	251,623	286,974
Acquired Loans | One-to-four family residential mortgage | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	23,430	30,665
Acquired Loans | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	250,373	285,137
Acquired Loans | One-to-four family residential mortgage | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	23,295	30,199
Acquired Loans | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	455	502
Acquired Loans | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	795	1,335
Acquired Loans | One-to-four family residential mortgage | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	135	466
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	274,825	317,219
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	251,395	286,554
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	23,430	30,665
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	250,373	285,137
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	23,295	30,199
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	455	502
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	567	915
Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	135	466
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	228	420
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	228	420
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	228	420
Acquired Loans | One-to-four family residential mortgage | Non-Performing Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	17,201	20,887
Acquired Loans | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	17,201
Acquired Loans | Construction and land | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net		20,887
Acquired Loans | Construction and land | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	17,201	20,887
Acquired Loans | Construction and land | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	17,201
Acquired Loans | Construction and land | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		20,887
Acquired Loans | Construction and land | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Construction and land | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0
Acquired Loans | Construction and land | Non-Performing Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Acquired Loans | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	199,149	215,389
Acquired Loans | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	189,782	205,391
Acquired Loans | Multifamily | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	9,367	9,998
Acquired Loans | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	189,551	205,025
Acquired Loans | Multifamily | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	8,950	9,569
Acquired Loans | Multifamily | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	78	210
Acquired Loans | Multifamily | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net		429
Acquired Loans | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	153	156
Acquired Loans | Multifamily | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	417
Acquired Loans | Multifamily | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	198,732	215,389
Acquired Loans | Multifamily | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	189,782	205,391
Acquired Loans | Multifamily | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,950	9,998
Acquired Loans | Multifamily | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	189,551	205,025
Acquired Loans | Multifamily | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,950	9,569
Acquired Loans | Multifamily | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	78	210
Acquired Loans | Multifamily | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		429
Acquired Loans | Multifamily | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	153	156
Acquired Loans | Multifamily | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
Acquired Loans | Multifamily | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	417	0
Acquired Loans | Multifamily | Non-Performing Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Multifamily | Non-Performing Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	417	0
Acquired Loans | Multifamily | Non-Performing Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Multifamily | Non-Performing Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Multifamily | Non-Performing Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Multifamily | Non-Performing Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Acquired Loans | Multifamily | Non-Performing Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Multifamily | Non-Performing Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	417
Acquired Loans | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	20,455	25,522
Acquired Loans | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	20,291	25,385
Acquired Loans | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	164	137
Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	20,378	25,483
Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	20,291	25,385
Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	87	98
Acquired Loans | Home equity and lines of credit | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	77	39
Acquired Loans | Home equity and lines of credit | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Home equity and lines of credit | Non-Performing Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	77	39
Acquired Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	16,946	25,443
Acquired Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	16,944	25,419
Acquired Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	2	24
Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	16,944	25,434
Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	16,944	25,419
Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	15
Acquired Loans | Commercial and Industrial | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	2	9
Acquired Loans | Commercial and Industrial | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Acquired Loans | Commercial and Industrial | Non-Performing Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	2	9
Acquired Loans | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	37
Acquired Loans | Other loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net		359
Acquired Loans | Other loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	36
Acquired Loans | Other loans | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		359
Acquired Loans | Other loans | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	1
Acquired Loans | Other loans | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Total Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated loans held-for-investment, net	3,118,078	2,937,586
Total Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,112,542	2,930,205
Total Loans | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	5,536	7,381
0-29 Days Past Due | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	511	1,185
0-29 Days Past Due | Loans Held For Investment | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,410,842	2,130,390
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	439,356	405,127
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	84,620	66,368
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	354,736	338,759
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	84,620	65,189
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	346,229	322,307
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	832	3,852
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		1,179
0-29 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	7,675	12,600
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	97,287	102,131
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	58,229	57,376
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	39,058	44,755
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	57,907	56,787
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	38,504	43,316
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	322	589
0-29 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	554	1,439
0-29 Days Past Due | Loans Held For Investment | Construction and land | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,614	14,092
0-29 Days Past Due | Loans Held For Investment | Construction and land | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,614	14,092
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,735,923	1,509,157
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	131,488	122,550
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,604,435	1,386,607
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	131,488	122,525
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,603,714	1,380,331
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		25
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	638	4,636
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
0-29 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	83	1,640
0-29 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	67,600	66,551
0-29 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	67,426	66,369
0-29 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	28	29
0-29 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	146	153
0-29 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,659	31,880
0-29 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	34,003	31,040
0-29 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	547	696
0-29 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	109	144
0-29 Days Past Due | Loans Held For Investment | Other loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,403	1,452
0-29 Days Past Due | Loans Held For Investment | Other loans | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,403	1,452
0-29 Days Past Due | Acquired Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	689,656	789,715
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	161,954	186,135
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	50,126	62,338
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	111,828	123,797
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	50,035	61,646
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	108,125	119,932
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	91	286
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	446
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	406
0-29 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,703	3,419
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	274,451	316,730
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	251,021	286,272
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	23,430	30,458
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	250,149	285,116
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	23,295	30,199
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	455	502
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	417	654
0-29 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	135	259
0-29 Days Past Due | Acquired Loans | Construction and land | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	17,201	20,887
0-29 Days Past Due | Acquired Loans | Construction and land | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	17,201
0-29 Days Past Due | Acquired Loans | Construction and land | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		20,887
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	198,732	214,849
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	189,782	205,280
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,950	9,569
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	189,551	205,025
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,950	9,569
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	78	99
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	153	156
0-29 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
0-29 Days Past Due | Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	20,378	25,340
0-29 Days Past Due | Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	20,291	25,340
0-29 Days Past Due | Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	87	0
0-29 Days Past Due | Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	16,904	25,419
0-29 Days Past Due | Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	16,904	25,419
0-29 Days Past Due | Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
0-29 Days Past Due | Acquired Loans | Other loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	36
0-29 Days Past Due | Acquired Loans | Other loans | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		355
0-29 Days Past Due | Total Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,100,498	2,920,105
30-89 Days Past Due | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,939	479
30-89 Days Past Due | Loans Held For Investment | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	10,658	7,333
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,374	3,002
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	410	423
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,964	2,579
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	423
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	628	1,535
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	410
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,338	0
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
30-89 Days Past Due | Loans Held For Investment | Commercial mortgage | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	998	1,044
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,790	3,132
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,790	3,132
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,493	2,427
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	683	705
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	614	0
30-89 Days Past Due | Loans Held For Investment | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans Held For Investment | Construction and land | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	6	0
30-89 Days Past Due | Loans Held For Investment | Construction and land | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	6	0
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,297	900
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	304	0
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,993	900
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	304	0
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	233	900
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,259	0
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
30-89 Days Past Due | Loans Held For Investment | Multifamily | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,501	0
30-89 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	120
30-89 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	120
30-89 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans Held For Investment | Home equity and lines of credit | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	162	133
30-89 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	138	133
30-89 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	24	0
30-89 Days Past Due | Loans Held For Investment | Commercial and Industrial | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans Held For Investment | Other loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	29	46
30-89 Days Past Due | Loans Held For Investment | Other loans | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	29	46
30-89 Days Past Due | Acquired Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,386	2,767
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	972	1,576
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	251	1,047
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	721	529
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	70	7
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	158	132
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	133	138
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	181	1,040
30-89 Days Past Due | Acquired Loans | Commercial mortgage | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	430	259
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	374	489
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	374	282
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	207
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	224	21
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Pass | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	150	261
30-89 Days Past Due | Acquired Loans | One-to-four family residential mortgage | Performing (Accruing) Loans | Substandard | Greater than or Equal to 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	207
30-89 Days Past Due | Acquired Loans | Construction and land | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Acquired Loans | Construction and land | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
30-89 Days Past Due | Acquired Loans | Construction and land | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	540
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	111
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	429
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Pass | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	111
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Special Mention | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		429
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Acquired Loans | Multifamily | Performing (Accruing) Loans | Substandard | Greater Than or Equal to 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
30-89 Days Past Due | Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	143
30-89 Days Past Due | Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	45
30-89 Days Past Due | Acquired Loans | Home equity and lines of credit | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	98
30-89 Days Past Due | Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	40	15
30-89 Days Past Due | Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	40	0
30-89 Days Past Due | Acquired Loans | Commercial and Industrial | Performing (Accruing) Loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	15
30-89 Days Past Due | Acquired Loans | Other loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
30-89 Days Past Due | Acquired Loans | Other loans | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		4
30-89 Days Past Due | Total Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	$ 12,044	$ 10,100

Loans - Summary Of Impaired Loa

Loans - Summary Of Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Related Allowance	$ (82)	$ (328)
Recorded investment	21,085	26,290
Unpaid Principal Balance	23,638	29,352
Commercial mortgage
Financing Receivable, Impaired [Line Items]
Related Allowance	0	(64)
Recorded investment	16,008	20,710
Unpaid Principal Balance	17,849	23,073
Commercial mortgage | Pass | Greater Than or Equal to 35% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	6,263	3,911
Unpaid Principal Balance With No Related Allowance Recorded	7,150	4,047
Commercial mortgage | Substandard | Less Than 35% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	0	0
Unpaid Principal Balance With No Related Allowance Recorded	139	139
Commercial mortgage | Substandard | Greater Than or Equal to 35% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	9,745	14,780
Unpaid Principal Balance With No Related Allowance Recorded	10,560	16,868
Recorded Investment With a Related Allowance Recorded	0	2,019
Unpaid Principal Balance With a Related Allowance Recorded	0	2,019
Related Allowance	0	(64)
One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Related Allowance	(75)	(141)
Recorded investment	3,387	3,615
Unpaid Principal Balance	3,628	3,843
One-to-four family residential mortgage | Pass | Less Than 60% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	1,189	633
Unpaid Principal Balance With No Related Allowance Recorded	1,254	633
Recorded Investment With a Related Allowance Recorded	411	0
Unpaid Principal Balance With a Related Allowance Recorded	411	0
Related Allowance	(7)	0
One-to-four family residential mortgage | Pass | Greater than or Equal to 60% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	136	0
Unpaid Principal Balance With No Related Allowance Recorded	161	0
Recorded Investment With a Related Allowance Recorded	268	275
Unpaid Principal Balance With a Related Allowance Recorded	268	275
Related Allowance	(19)	(3)
One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With a Related Allowance Recorded	0	0
Unpaid Principal Balance With a Related Allowance Recorded	0	0
Related Allowance	0	0
One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	251	184
Unpaid Principal Balance With No Related Allowance Recorded	251	184
Recorded Investment With a Related Allowance Recorded	997	1,522
Unpaid Principal Balance With a Related Allowance Recorded	997	1,522
Related Allowance	(49)	(97)
One-to-four family residential mortgage | Substandard | Greater than or Equal to 60% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	135	620
Unpaid Principal Balance With No Related Allowance Recorded	286	848
Recorded Investment With a Related Allowance Recorded	0	381
Unpaid Principal Balance With a Related Allowance Recorded	0	381
Related Allowance	0	(41)
Construction and land
Financing Receivable, Impaired [Line Items]
Related Allowance	0	0
Recorded investment	0	0
Unpaid Principal Balance	0	0
Multifamily
Financing Receivable, Impaired [Line Items]
Related Allowance	0	(95)
Recorded investment	1,462	1,528
Unpaid Principal Balance	1,933	1,999
Multifamily | Pass | Greater Than or Equal to 35% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	1,309	63
Unpaid Principal Balance With No Related Allowance Recorded	1,780	534
Recorded Investment With a Related Allowance Recorded	0	1,309
Unpaid Principal Balance With a Related Allowance Recorded	0	1,309
Related Allowance	0	(95)
Multifamily | Substandard | Less Than 35% LTV
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	153	156
Unpaid Principal Balance With No Related Allowance Recorded	153	156
Home equity and lines of credit
Financing Receivable, Impaired [Line Items]
Related Allowance	(4)	(23)
Recorded investment	69	336
Unpaid Principal Balance	69	336
Home equity and lines of credit | Pass
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	33	39
Unpaid Principal Balance With No Related Allowance Recorded	33	39
Recorded Investment With a Related Allowance Recorded	0	258
Unpaid Principal Balance With a Related Allowance Recorded	0	258
Related Allowance	0	(5)
Home equity and lines of credit | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With a Related Allowance Recorded	36	39
Unpaid Principal Balance With a Related Allowance Recorded	36	39
Related Allowance	(4)	(18)
Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Related Allowance	(3)	(5)
Recorded investment	159	101
Unpaid Principal Balance	159	101
Commercial and Industrial | Special Mention
Financing Receivable, Impaired [Line Items]
Recorded Investment With a Related Allowance Recorded	24	26
Unpaid Principal Balance With a Related Allowance Recorded	24	26
Related Allowance	(3)	(5)
Commercial and Industrial | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Related Allowance Recorded	135	75
Unpaid Principal Balance With No Related Allowance Recorded	$ 135	$ 75

Loans - Impaired loans (Details

Loans - Impaired loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Loans with carrying balances not written down	$ 14,500	$ 11,500
Average recorded investment	23,797	29,869
Interest income	1,009	943
Commercial mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment	18,322	23,633
Interest income	810	743
One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment	3,422	3,729
Interest income	133	114
Multifamily
Financing Receivable, Impaired [Line Items]
Average recorded investment	1,675	2,053
Interest income	62	73
Home equity and lines of credit
Financing Receivable, Impaired [Line Items]
Average recorded investment	226	346
Interest income	3	12
Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Average recorded investment	152	108
Interest income	1	1
Pass | Home equity and lines of credit
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	36	8
Interest income, with no related allowance	2	3
Average recorded investment, with a related allowance	153	264
Interest income, with a related allowance	0	8
Special Mention | Home equity and lines of credit
Financing Receivable, Impaired [Line Items]
Average recorded investment, with a related allowance	0	34
Interest income, with a related allowance	0	0
Special Mention | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Average recorded investment, with a related allowance	25	27
Interest income, with a related allowance	1	1
Substandard | Home equity and lines of credit
Financing Receivable, Impaired [Line Items]
Average recorded investment, with a related allowance	37	40
Interest income, with a related allowance	1	1
Substandard | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	127	81
Interest income, with no related allowance	0	0
Less Than 35% LTV | Substandard | Commercial mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	0	0
Interest income, with no related allowance	45	39
Less Than 35% LTV | Substandard | Multifamily
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	154	62
Interest income, with no related allowance	6	6
Greater Than or Equal to 35% LTV | Pass | Commercial mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	5,516	3,980
Interest income, with no related allowance	334	192
Greater Than or Equal to 35% LTV | Pass | Multifamily
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	563	69
Interest income, with no related allowance	56	17
Average recorded investment, with a related allowance	778	794
Interest income, with a related allowance	0	50
Greater Than or Equal to 35% LTV | Special Mention | Commercial mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	0	0
Interest income, with no related allowance	0	0
Greater Than or Equal to 35% LTV | Substandard | Commercial mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	12,402	13,853
Interest income, with no related allowance	431	450
Average recorded investment, with a related allowance	404	5,800
Interest income, with a related allowance	0	62
Greater Than or Equal to 35% LTV | Substandard | Multifamily
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	0	582
Interest income, with no related allowance	0	0
Average recorded investment, with a related allowance	180	546
Interest income, with a related allowance	0	0
Less Than 60% LTV | Pass | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	854	559
Interest income, with no related allowance	56	31
Average recorded investment, with a related allowance	165	137
Interest income, with a related allowance	7	0
Less Than 60% LTV | Special Mention | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with a related allowance	0	0
Interest income, with a related allowance	0	0
Less Than 60% LTV | Substandard | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	372	213
Interest income, with no related allowance	14	21
Average recorded investment, with a related allowance	1,264	1,575
Interest income, with a related allowance	20	26
Greater than or Equal to 60% LTV | Pass | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	55	0
Interest income, with no related allowance	4	0
Average recorded investment, with a related allowance	271	110
Interest income, with a related allowance	19	6
Greater than or Equal to 60% LTV | Special Mention | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with a related allowance	0	0
Interest income, with a related allowance	0	0
Greater than or Equal to 60% LTV | Substandard | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average recorded investment, with no related allowance	289	339
Interest income, with no related allowance	13	26
Average recorded investment, with a related allowance	152	796
Interest income, with a related allowance	$ 0	$ 4

Loans - Narrative, TDR (Details

Loans - Narrative, TDR (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDR that subsequently defaulted | contract	1
Number of real estate relationships | contract		0
Troubled debt restructurings | $	$ 18,300	$ 22,400
One-to-four family residential mortgage
Financing Receivable, Modifications [Line Items]
Pre-modification outstanding recorded investment | $	$ 256

Premises and Equipment, Net - P

Premises and Equipment, Net - Premises and Equipment Less Accumulated Depreciation and Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 66,899	$ 64,834
Accumulated depreciation and amortization	(41,153)	(37,924)
Premises and equipment, net	25,746	26,910
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	4,018	4,018
Buildings and improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	8,883	8,856
Capital leases
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	2,600	2,600
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	22,677	21,962
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 28,721	$ 27,398

Premises and Equipment, Net - N

Premises and Equipment, Net - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 3,200,000	$ 3,600,000	$ 3,400,000
Gain on sale of premises and equipment	$ 0	$ 0	$ 0

Deposits - Deposit Account Bala

Deposits - Deposit Account Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
Negotiable orders of withdrawal	$ 465,140	$ 467,440
Non-interest-bearing demand	407,267	390,484
Total transactions	872,407	857,924
Money market	800,854	818,660
Savings	424,789	500,926
Total savings	1,225,643	1,319,586
$100000	401,063	484,480
$100,000 or more	337,866	51,597
Total certificates of deposit	738,929	536,077
Total deposits	$ 2,836,979	$ 2,713,587
Weighted Average Rate, Negotiable orders of withdrawal	0.39%	0.34%
Weighted Average Rate, Total transactions	0.21%	0.19%
Weighted Average Rate, Money market	0.72%	0.67%
Weighted Average Rate, Savings	0.18%	0.24%
Weighted Average Rate, Total Savings	0.53%	0.51%
Weighted Average Rate, Under $100,000	1.42%	1.22%
Weighted Average Rate, $100,000 or more	1.51%	1.48%
Weighted Average Rate, Total certificates of deposit	1.46%	1.24%
Weighted Average Rate, Total deposits	0.67%	0.55%

Deposits - Narrative (Details)

Deposits - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Certificates of Deposit
Time Deposits [Line Items]
Brokered deposits	$ 150.6	$ 98.8

Deposits - Maturities Of Certif

Deposits - Maturities Of Certificates Of Deposit (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
2,018	$ 401,315
2,019	157,397
2,020	122,899
2,021	23,511
2,022	33,807
Thereafter	0
Total certificates of deposit	$ 738,929	$ 536,077

Deposits - Interest Expense On

Deposits - Interest Expense On Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
Negotiable order of withdrawal and money market	$ 7,336	$ 5,634	$ 2,816
Savings-passbook and statement	897	2,124	2,141
Certificates of deposit	8,153	6,529	5,466
Total interest expense on deposits	$ 16,386	$ 14,287	$ 10,423

Borrowings - Summary Of Borrowi

Borrowings - Summary Of Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Repurchase agreements	$ 2,000	$ 8,000
Other borrowings:
FHLB advances	464,217	453,220
Floating rate advances	5,033	11,463
Obligations under capital leases	299	523
Total long term debt	$ 471,549	$ 473,206

Borrowings - Contractual Maturi

Borrowings - Contractual Maturities Repurchase Agreements And FHLB Advances (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Long Term Debt Maturities Repayments Of Principal [Line Items]
Total long term debt	$ 471,549	$ 473,206
Repurchase agreements
Long Term Debt Maturities Repayments Of Principal [Line Items]
2,018	2,000
2,019	0
2,020	0
2,021	0
2,022	0
Total long term debt	2,000
FHLB advances
Long Term Debt Maturities Repayments Of Principal [Line Items]
2,018	160,715
2,019	123,502
2,020	90,000
2,021	70,000
2,022	20,000
Total long term debt	$ 464,217

Borrowings - Narrative (Details

Borrowings - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017
Schedule Of Short Term And Long Term Debt [Line Items]
FHLB advances		$ 870.8
Unencumbered securities		72.6
Multifamily loans held as collateral		$ 885.3
Repurchase agreements
Schedule Of Short Term And Long Term Debt [Line Items]
Weighted average interest rate	3.19%	3.39%
Maturity in the first quarter	$ 4	$ 2
Maturity in more than 90 days	4
Repurchase agreements | Mortgage Backed Securities
Schedule Of Short Term And Long Term Debt [Line Items]
Mortgage-backed securities amortized cost	13.7	4.7
Mortgage-backed securities held for sale fair value	$ 13.9	$ 4.6
Repurchase agreements | Maturity over 90 days
Schedule Of Short Term And Long Term Debt [Line Items]
Maturity period	90 days

Borrowings - Summary Of Interes

Borrowings - Summary Of Interest Expense On Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Expense [Line Items]
Interest expense	$ 7,590	$ 7,381	$ 9,265
Obligations under capital leases
Interest Expense [Line Items]
Interest expense	30	42	60
FHLB advances
Interest Expense [Line Items]
Interest expense	7,390	6,743	6,742
Floating rate advances
Interest Expense [Line Items]
Interest expense	33	27	17
Repurchase agreements
Interest Expense [Line Items]
Interest expense	$ 137	$ 569	$ 2,446

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Federal tax expense (benefit):
Current	$ 10,113	$ 14,218	$ 11,796
Deferred	14,290	(1,260)	(2,305)
Federal tax expense (benefit)	24,403	12,958	9,491
State and local tax expense (benefit):
Current	1,672	2,506	1,811
Deferred	903	(1,799)	673
State and local tax expense (benefit)	2,575	707	2,484
Income tax expense	$ 26,978	$ 13,665	$ 11,975

Income Taxes - Reconciliation B

Income Taxes - Reconciliation Between The Amount Of Reported Total Income Tax Expense And The Amount Computed By Multiplying The Applicable Statutory Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Tax expense at statutory rate of 35%	$ 18,111	$ 13,928	$ 11,027
Increase (decrease) in taxes resulting from:
State tax, net of federal income tax	1,674	460	1,615
Impact of 2017 federal tax reform	10,453	0	0
Bank owned life insurance	(1,885)	(1,399)	(1,319)
ESOP fair market value adjustment	404	352	0
Incentive stock options	247	299	210
Uncertain tax position	132	178	51
Merger related costs	0	74	201
Excess tax benefits from employee share based payments	(2,309)
Other, net	151	(227)	190
Income tax expense	$ 26,978	$ 13,665	$ 11,975

Income Taxes - Tax Effects Of T

Income Taxes - Tax Effects Of Temporary Differences That Give Rise To Significant Portions Of The Deferred Tax Assets And Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Allowance for loan losses	$ 6,836	$ 9,470
Capitalized leases	84	213
Deferred compensation	3,474	5,686
Accrued salaries	2	1,128
Postretirement benefits	381	576
Equity awards	3,582	5,005
Unrealized actuarial losses on post-retirement benefits	93	124
Straight-line leases adjustment	892	1,219
Asset retirement obligation	65	89
Reserve for accrued interest receivable	712	1,116
Reserve for loan commitments	124	193
Employee Stock Ownership Plan	497	642
Other	236	366
Depreciation	2,116	2,509
Fair value adjustments of acquired loans	4,868	10,168
Fair value adjustments of pension benefit obligations	154	250
Unrealized losses on securities	2,070	2,775
Total gross deferred tax assets	26,186	41,529
Deferred tax liabilities:
Fair value adjustments of acquired securities	35	82
Fair value adjustments of deposit liabilities	358	547
Deferred loan fees	1,815	1,910
Undistributed earnings related to NSB Realty Trust	939	0
Other	37	59
Total gross deferred tax liabilities	3,184	2,598
Net deferred tax asset	$ 23,002	$ 38,931

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Re-measurement of our net deferred tax asset	$ 10,500
Operating Loss Carryforwards [Line Items]
Net deferred tax asset	23,002	$ 38,931
Bad debt base year reserve	5,900	5,900
Federal tax bad debt deferred tax liability	$ 2,800	2,800
Hopewell Valley Community Bank
Operating Loss Carryforwards [Line Items]
Net deferred tax asset		$ 3,900

Income Taxes - Reconciliation O

Income Taxes - Reconciliation Of Uncertain Tax Position (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 459	$ 281	$ 230
Settlements based on tax positions related to prior years	(109)	0	0
Additions based on tax positions related to prior years	132	178	51
Ending balance	$ 459	$ 281	$ 230	$ 482

Retirement Benefits - Narrative

Retirement Benefits - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Requisite service period for employees to be eligible for 401(k) plan	3 months
Percent of employer match on employee contributions	25.00%
Percent of base compensation contributed by eligible employees	6.00%
Contribution plan participation period (years)	3 years
Contribution plan subsequent participation period (years)	3 years
Requisite service period for members to become fully vested	5 years
Company contribution amount	$ 387	$ 384	$ 321
ESOP compensation expense	2,200	2,000	1,900
Estimated loss that will be amortized from accumulated other comprehensive income (loss) into net periodic cost	25
Prior service cost that will be amortized from accumulated other comprehensive income (loss) into net periodic cost	0
Transition obligation that will be amortized from accumulated other comprehensive income (loss) into net periodic cost	$ 0
Medical cost trend rate	8.75%
Medical cost trend rate reduction percent per year	0.50%
Medical cost trend rate ultimate rate	4.75%
Benefits paid	$ 112	118	116
Benefits expected to be paid under the postretirement health benefits plan in 2018	121
Benefits expected to be paid under the postretirement health benefits plan in 2019	124
Benefits expected to be paid under the postretirement health benefits plan in 2020	126
Benefits expected to be paid under the postretirement health benefits plan in 2021	127
Benefits expected to be paid under the postretirement health benefits plan in 2022	127
Benefits expected to be paid under the postretirement health benefits plan in 2023 through 2027	594
Supplemental Employee Retirement Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	13,700	14,100
Net postretirement benefit cost included in compensation and employee benefits	$ 1,100	(503)	(392)
Minimum
Defined Benefit Plan Disclosure [Line Items]
Percent of compensation employees can invest in 401(k) plan	2.00%
Matching contribution percent	25.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Percent of compensation employees can invest in 401(k) plan	15.00%
Matching contribution percent	50.00%
First ESOP
Defined Benefit Plan Disclosure [Line Items]
Employee stock ownership plan, shares authorized and purchased	2,463,884
Initial public offering price (usd per share)	$ 7.13
Outstanding loan balance	$ 11,500	$ 12,100
Shares released and allocated to participants (in shares)	99,670	97,836
Second ESOP
Defined Benefit Plan Disclosure [Line Items]
Employee stock ownership plan, shares authorized and purchased	1,422,357
Initial public offering price (usd per share)	$ 10
Outstanding loan balance	$ 12,600	$ 12,900
Shares released and allocated to participants (in shares)	51,189	50,086
Supplemental ESOP
Defined Benefit Plan Disclosure [Line Items]
Company contribution to SESOP plan	$ 84	$ 82	$ 82

Retirement Benefits - Funded St

Retirement Benefits - Funded Status And Components Of Post Retirement Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid	$ (112)	$ (118)	$ (116)
Other Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Accumulated postretirement benefit obligation beginning of year	1,697	1,950	1,846
Service cost	11	8	9
Interest cost	57	71	62
Actuarial (gain) loss	(8)	(214)	149
Benefits paid	(112)	(118)	(116)
Accumulated postretirement benefit obligation end of year	1,645	1,697	1,950
Accrued liability (included in accrued expenses and other liabilities)	$ 1,645	$ 1,697	$ 1,950

Retirement Benefits - Amounts R

Retirement Benefits - Amounts Recognized In Accumulated Other Comprehensive Income (Loss) (Details) - Other Pension Plans, Defined Benefit - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Net loss	$ 274	$ 310
Transition obligation	0	0
Prior service cost	0	0
Loss recognized in accumulated other comprehensive income (loss)	$ 274	$ 310

Retirement Benefits - Component

Retirement Benefits - Components Of Net Periodic Post Retirement Benefit Cost (Details) - Other Pension Plans, Defined Benefit - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 11	$ 8	$ 9
Interest cost	57	71	62
Amortization of transition obligation	0	0	17
Amortization of prior service costs	0	12	38
Amortization of unrecognized loss	28	54	44
Net postretirement benefit cost included in compensation and employee benefits	$ 96	$ 145	$ 170

Retirement Benefits - Defined B

Retirement Benefits - Defined Benefit Plan, Assumptions Used In Accounting For The Plan (Details) - Other Pension Plans, Defined Benefit	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assumptions used to determine benefit obligation at period end:
Discount rate	3.25%	3.50%	3.75%
Rate of increase in compensation	4.00%	4.00%	4.00%
Assumptions used to determine net periodic benefit cost for the year:
Discount rate	3.50%	3.75%	3.50%
Rate of increase in compensation	4.00%	4.00%	4.00%

Retirement Benefits - Summary O

Retirement Benefits - Summary Of Percentage Point Change In Assumed Health Care Cost Trends (Details) - Other Pension Plans, Defined Benefit - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Aggregate of service and interest components of net periodic cost (benefit), one percentage point increase	$ 4	$ 6	$ 6
Aggregate of service and interest components of net periodic cost (benefit), one percentage point decrease	(4)	(5)	$ (4)
Effect on accumulated postretirement benefit obligation, one percentage point increase	111	121
Effect on accumulated postretirement benefit obligation, one percentage point decrease	$ (100)	$ (108)

Equity Incentive Plan - Narrati

Equity Incentive Plan - Narrative (Details) - USD ($) $ in Millions	Nov. 01, 2017	Sep. 19, 2017	Aug. 01, 2017	Nov. 16, 2016	May 27, 2015	May 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)							34,500	20,000
Stock options granted (in shares)							98,244	40,000
Allocated stock-based compensation expense							$ 6.2	$ 7.3	$ 6.8
2008 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)							4,311,796
Vesting period (years)								5 years
Beginning of vesting period (years)								1 year
2014 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)							4,978,249
Vesting period (years)							5 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected future stock-based compensation expense							$ 5.4
Average period of expected future stock option expense							1 year 10 months 24 days
Restricted Stock | 2008 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)							1,231,941
Shares available for issuance under equity incentive plan (in shares)							3,378
Restricted Stock | 2008 Equity Incentive Plan | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance under equity incentive plan (in shares)							34,500
Restricted Stock | 2008 Equity Incentive Plan | Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance under equity incentive plan (in shares)							20,000
Restricted Stock | 2014 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)							1,422,357
Shares available for issuance under equity incentive plan (in shares)							148,816
Restricted shares granted (in shares)						419,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected future stock-based compensation expense							$ 3.9
Average period of expected future stock option expense							1 year 10 months 24 days
Stock Options | 2008 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)							3,079,855
Shares available for issuance under equity incentive plan (in shares)							17,299
Stock option expiration period (years)							10 years
Stock options granted (in shares)	40,000,000	12,500,000	45,744,000	40,000,000
Expected life	5 years 9 months	5 years 9 months	5 years 9 months	6 years 6 months
Risk-free rate of return	2.06%	1.89%	1.86%	1.80%
Volatility	29.22%	30.06%	29.46%	30.07%
Dividend yield	2.37%	1.98%	1.91%	1.74%
Stock Options | 2008 Equity Incentive Plan | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance under equity incentive plan (in shares)							98,244
Stock Options | 2008 Equity Incentive Plan | Director | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (years)							10 months
Stock Options | 2008 Equity Incentive Plan | Director | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (years)							34 months
Stock Options | 2008 Equity Incentive Plan | Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance under equity incentive plan (in shares)							40,000
Stock Options | 2014 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)							3,555,892
Shares available for issuance under equity incentive plan (in shares)							330,273
Beginning of vesting period (years)						1 year
Stock option expiration period (years)						10 years
Stock options granted (in shares)						1,090,000
Expected life					6 years 6 months
Risk-free rate of return					1.67%
Volatility					32.06%
Dividend yield					1.90%

Equity Incentive Plan - Valuati

Equity Incentive Plan - Valuation Assumptions (Details) - shares	Nov. 01, 2017	Sep. 19, 2017	Aug. 01, 2017	Nov. 16, 2016	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)					98,244	40,000
2008 Equity Incentive Plan | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	40,000,000	12,500,000	45,744,000	40,000,000
Risk-free rate of return	2.06%	1.89%	1.86%	1.80%
Volatility	29.22%	30.06%	29.46%	30.07%
Dividend yield	2.37%	1.98%	1.91%	1.74%
Expected life	5 years 9 months	5 years 9 months	5 years 9 months	6 years 6 months

Equity Incentive Plan - Stock O

Equity Incentive Plan - Stock Options Outstanding (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Stock Options
Outstanding (shares) - Beginning Balance	5,328,670	6,011,861
Granted (shares)	98,244	40,000
Forfeited (shares)	(247,484)	(32,520)
Exercised (shares)	(558,743)	(690,671)
Outstanding (shares) - Ending Balance	4,620,687	5,328,670	6,011,861
Exercisable (shares)	3,118,615
Weighted Average Grant Date Fair Value
Outstanding (usd per share) - Beginning Balance	$ 3.41	$ 3.30
Granted (usd per share)	4.04	4.94
Forfeited (usd per share)	3.93	4
Exercised (usd per share)	2.41	2.52
Outstanding (usd per share) - Ending Balance	3.51	3.41	$ 3.30
Exercisable (usd per share)	3.25
Weighted Average Exercise Price
Outstanding (usd per share) - Beginning Balance	11.36	10.93
Granted (usd per share)	16.73	18.44
Forfeited (usd per share)	13.68	13.78
Exercised (usd per share)	7.52	7.84
Outstanding (usd per share) - Ending Balance	11.82	$ 11.36	$ 10.93
Exercisable (usd per share)	$ 10.75
Outstanding, weighted average contractual life (years)	5 years 2 months 1 day	5 years 9 months 11 days	6 years 4 months 28 days
Granted, weighted average contractual life (years)	9 years 8 months 16 days	9 years 10 months 17 days
Exercisable, weighted average contractual life (years)	4 years 3 months 4 days

Equity Incentive Plan - Status

Equity Incentive Plan - Status Of The Company's Restricted Share Awards (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Number of Shares Awarded
Non-vested (shares) - Beginning Balance	924,002	1,193,862
Granted (shares)	34,500	20,000
Vested (shares)	(279,660)	(277,580)
Forfeited (shares)	(92,947)	(12,280)
Non-vested (shares) - Ending Balance	585,895	924,002
Weighted Average Grant Date Fair Value
Non-vested (usd per share) - Beginning Balance	$ 13.82	$ 13.70
Granted (usd per share)	16.70	18.44
Vested (usd per share)	13.68	13.61
Forfeited (usd per share)	13.92	13.87
Non-vested (usd per share) - Ending Balance	$ 14.05	$ 13.82

Commitments and Contingencies -

Commitments and Contingencies - Commitment and Contingent Liabilities Not Reflected in Consolidated Financial Statements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Commitments to extend credit
Commitments and contingent liabilities	$ 43,611	$ 46,069
Unused lines of credit
Commitments and contingent liabilities	98,433	78,825
Standby letters of credit
Commitments and contingent liabilities	$ 7,000	$ 7,463

Commitments and Contingencies91

Commitments and Contingencies - Narrative (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Oct. 31, 2017USD ($)ft²	Jul. 31, 2017USD ($)ft²	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Operating Leased Assets [Line Items]
Guarantees extend term period (years)			1 year
Allowance for estimated losses on commitments			$ 442	$ 475
Future minimum payments due			60,205
Net rental expense			$ 5,300	$ 5,200	$ 4,600
Agreements term (years)			3 years
Building
Operating Leased Assets [Line Items]
Renewal term		10 years 8 months
NEW JERSEY | Building
Operating Leased Assets [Line Items]
Increase in area | ft²		6,919
Future minimum payments due		$ 9,400
NEW YORK | Building
Operating Leased Assets [Line Items]
Future minimum payments due	$ 2,500
Lease area | ft²	3,600
Term of contract	15 years

Commitments and Contingencies92

Commitments and Contingencies - The Projected Minimum Annual Rental Payments And Receipts Under The Capitalized Leases And Operating Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
Capitalized Leases, 2018	$ 262
Capitalized Leases, 2019	44
Capitalized Leases, 2020	0
Capitalized Leases, 2021	0
Capitalized Leases, 2022	0
Capitalized Leases, Thereafter	0
Capitalized Leases, Total minimum lease payments	306
Operating Leases, 2018	4,867
Operating Leases, 2019	5,167
Operating Leases, 2020	5,334
Operating Leases, 2021	4,885
Operating Leases, 2022	4,204
Operating Leases, Thereafter	35,748
Operating Leases, Total minimum lease payments	$ 60,205

Regulatory Requirements - Narra

Regulatory Requirements - Narrative (Details)	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2016	Dec. 31, 2015	Jan. 01, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity Tier 1 capital (to risk-weighted assets), for capital adequacy purposes ratio		4.50%	4.50%			4.50%
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes ratio		6.00%	6.00%		4.00%	6.00%
Total capital (to risk-weighted assets), for capital adequacy purposes ratio		8.00%	8.00%
Tier 1 capital (core) (to adjusted total assets), for capital adequacy purposes ratio		4.00%	4.00%
Tier 1 capital (core) (to adjusted total assets), for well capitalized under prompt corrective action provisions ratio		5.00%	5.00%
Common equity Tier 1 capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions ratio		6.50%	6.50%
Tier 1 risk-based capital ratio		8.00%	8.00%
Total capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions ratio		10.00%	10.00%
Tier 1 risk-based capital required for capital adequacy to risk-weighted assets, higher risk weight						150.00%
Common equity Tier 1 capital (to risk-weighted assets), ratio		18.02%	18.79%
Capital conservation buffer		1.25%		0.625%
Subsequent Event
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation buffer	1.875%

Regulatory Requirements - Regul

Regulatory Requirements - Regulatory Capital Amounts And Ratios Compared To Regulatory Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Capital (to risk-weighted assets), amount	$ 604,208	$ 586,055
Common Equity Tier 1 Capital (to risk-weighted assets), ratio	18.02%	18.79%
Common Equity Tier 1 Capital (to risk-weighted assets), for capital adequacy purposes amount	$ 150,917	$ 140,329
Common Equity Tier 1 Capital (to risk-weighted assets), for capital adequacy purposes ratio	4.50%	4.50%		4.50%
Common Equity Tier 1 Capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions amount	$ 217,991	$ 202,698
Common Equity Tier 1 Capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions ratio	6.50%	6.50%
Tier 1 capital (core) (to adjusted total assets), amount	$ 604,208	$ 586,055
Tier 1 capital (core) (to adjusted total assets), ratio	15.27%	15.40%
Tier 1 capital (core) (to adjusted total assets), for capital adequacy purposes amount	$ 158,254	$ 152,213
Tier 1 capital (core) (to adjusted total assets), for capital adequacy purposes ratio	4.00%	4.00%
Tier 1 capital (core) (to adjusted total assets), for well capitalized under prompt corrective action provisions amount	$ 197,818	$ 190,267
Tier 1 capital (core) (to adjusted total assets), for well capitalized under prompt corrective action provisions ratio	5.00%	5.00%
Tier 1 capital (to risk-weighted assets), amount	$ 604,208	$ 586,055
Tier 1 capital (to risk-weighted assets), ratio	18.02%	18.79%
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes amount	$ 201,222	$ 187,106
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes ratio	6.00%	6.00%	4.00%	6.00%
Tier 1 capital (to risk-weighted assets) for well capitalized under prompt corrective action provisions amount	$ 268,296	$ 249,474
Tier 1 capital (to risk-weighted assets) for well capitalized under prompt corrective action provisions ratio	8.00%	8.00%
Total capital (to risk-weighted assets), actual	$ 630,853	$ 611,168
Total capital (to risk-weighted assets), ratio	18.81%	19.60%
Total capital (to risk-weighted assets), for capital adequacy purposes amount	$ 268,296	$ 249,474
Total capital (to risk-weighted assets), for capital adequacy purposes ratio	8.00%	8.00%
Total capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions amount	$ 335,370	$ 380,533
Total capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions ratio	10.00%	10.00%
Subsidiaries
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Capital (to risk-weighted assets), amount	$ 559,717	$ 553,715
Common Equity Tier 1 Capital (to risk-weighted assets), ratio	16.70%	17.75%
Common Equity Tier 1 Capital (to risk-weighted assets), for capital adequacy purposes amount	$ 150,862	$ 140,371
Common Equity Tier 1 Capital (to risk-weighted assets), for capital adequacy purposes ratio	4.50%	4.50%
Common Equity Tier 1 Capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions amount	$ 217,912	$ 202,758
Common Equity Tier 1 Capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions ratio	6.50%	6.50%
Tier 1 capital (core) (to adjusted total assets), amount	$ 559,717	$ 553,715
Tier 1 capital (core) (to adjusted total assets), ratio	14.15%	14.55%
Tier 1 capital (core) (to adjusted total assets), for capital adequacy purposes amount	$ 158,220	$ 152,213
Tier 1 capital (core) (to adjusted total assets), for capital adequacy purposes ratio	4.00%	4.00%
Tier 1 capital (core) (to adjusted total assets), for well capitalized under prompt corrective action provisions amount	$ 197,775	$ 190,267
Tier 1 capital (core) (to adjusted total assets), for well capitalized under prompt corrective action provisions ratio	5.00%	5.00%
Tier 1 capital (to risk-weighted assets), amount	$ 559,717	$ 553,715
Tier 1 capital (to risk-weighted assets), ratio	16.70%	17.75%
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes amount	$ 201,150	$ 187,161
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes ratio	6.00%	6.00%
Tier 1 capital (to risk-weighted assets) for well capitalized under prompt corrective action provisions amount	$ 268,200	$ 249,548
Tier 1 capital (to risk-weighted assets) for well capitalized under prompt corrective action provisions ratio	8.00%	8.00%
Total capital (to risk-weighted assets), actual	$ 586,361	$ 578,828
Total capital (to risk-weighted assets), ratio	17.49%	18.56%
Total capital (to risk-weighted assets), for capital adequacy purposes amount	$ 268,200	$ 249,548
Total capital (to risk-weighted assets), for capital adequacy purposes ratio	8.00%	8.00%
Total capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions amount	$ 335,250	$ 311,935
Total capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions ratio	10.00%	10.00%

Fair Value of Measurement - Fai

Fair Value of Measurement - Fair Value, Assets And Liabilities Measured On Recurring And Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	$ 515,121	$ 498,897
Trading securities	9,597	7,857
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	515,121	498,897
Trading securities	9,597	7,857
Total assets measured on a recurring basis	524,718	506,754
Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	323	271
Trading securities	9,597	7,857
Total assets measured on a recurring basis	9,920	8,128
Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	514,798	498,626
Trading securities	0	0
Total assets measured on a recurring basis	514,798	498,626
Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available-for-sale	0	0
Trading securities	0	0
Total assets measured on a recurring basis	0	0
Recurring Basis | GSE
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	445,224	448,842
Recurring Basis | GSE | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	0	0
Recurring Basis | GSE | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	445,224	448,842
Recurring Basis | GSE | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	0	0
Recurring Basis | Non-GSE
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	79	270
Recurring Basis | Non-GSE | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	0	0
Recurring Basis | Non-GSE | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	79	270
Recurring Basis | Non-GSE | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities	0	0
Recurring Basis | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	349	2,158
Recurring Basis | Municipal bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	0
Recurring Basis | Municipal bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	349	2,158
Recurring Basis | Municipal bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities		0
Recurring Basis | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	68,130	45,159
Recurring Basis | Corporate bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	0
Recurring Basis | Corporate bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	68,130	45,159
Recurring Basis | Corporate bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	0	0
Recurring Basis | Equity investments - mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	323	1,218
Recurring Basis | Equity investments - mutual funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	323	271
Recurring Basis | Equity investments - mutual funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	0	947
Recurring Basis | Equity investments - mutual funds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	0	0
Recurring Basis | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	1,016	1,250
Recurring Basis | Other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	0
Recurring Basis | Other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	1,016	1,250
Recurring Basis | Other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities	0	0
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	6,462	14,457
Commercial and industrial loans	21	21
Other real estate owned	850	850
Total assets measured on a non-recurring basis	7,333	15,328
Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Commercial and industrial loans	0	0
Other real estate owned	0	0
Total assets measured on a non-recurring basis	0	0
Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Commercial and industrial loans	0	0
Other real estate owned	0	0
Total assets measured on a non-recurring basis	0	0
Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	6,462	14,457
Commercial and industrial loans	21	21
Other real estate owned	850	850
Total assets measured on a non-recurring basis	7,333	15,328
Nonrecurring | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,645	10,730
Nonrecurring | Commercial real estate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | Commercial real estate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | Commercial real estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,645	10,730
Nonrecurring | One-to-four family residential mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	1,735	2,177
Nonrecurring | One-to-four family residential mortgage | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | One-to-four family residential mortgage | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | One-to-four family residential mortgage | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	1,735	2,177
Nonrecurring | Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	51	1,276
Nonrecurring | Multifamily | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | Multifamily | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | Multifamily | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	51	1,276
Nonrecurring | Home equity and lines of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	31	274
Nonrecurring | Home equity and lines of credit | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | Home equity and lines of credit | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Nonrecurring | Home equity and lines of credit | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 31	$ 274

Fair Value of Measurement - Qua

Fair Value of Measurement - Qualitative Information For Level 3 Assets Measured At Fair Value On A Non-Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Unobservable Inputs One | Impaired loans
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 6,483	$ 14,478
Valuation Methodology	Appraisals	Appraisals
Unobservable Inputs	Discount for costs to sell	Discount for costs to sell
Range of Inputs	7.00%	7.00%
Unobservable Inputs One | Other real estate owned
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 850	$ 850
Valuation Methodology	Appraisals	Appraisals
Unobservable Inputs	Discount for costs to sell	Discount for costs to sell
Range of Inputs	7.00%	7.00%
Unobservable Inputs Two | Impaired loans
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Unobservable Inputs	Discount for quick sale	Discount for quick sale
Range of Inputs	10.00%	10.00%
Unobservable Inputs Three | Impaired loans
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Valuation Methodology	Discounted cash flows	Discounted cash flows
Unobservable Inputs	Interest rates	Interest rates
Unobservable Inputs Three | Minimum | Impaired loans
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range of Inputs	3.125%	4.75%
Unobservable Inputs Three | Maximum | Impaired loans
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Range of Inputs	6.50%	7.50%

Fair Value of Measurement - Nar

Fair Value of Measurement - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Transfers of securities between Level 1 and Level 2	$ 0
Impaired loans held-for-investment and held-for-sale with outstanding principal balances	8,800,000	$ 17,700,000
Estimated fair value of impaired loans held-for-investment and held-for-sale	6,500,000	14,500,000
Decrease in reserve for impaired loans	246,000	562,000
Net impairment charge-offs	154,000	810,000
Assets acquired through foreclosure, or deed in lieu of foreclosure	$ 850,000	$ 850,000

Fair Value of Measurement - Est

Fair Value of Measurement - Estimated Fair Values Of The Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial assets:
Trading securities	$ 9,597	$ 7,857
Securities available-for-sale	515,121	498,897
Securities held-to-maturity	9,892	10,118
Carrying Value
Financial assets:
Cash and cash equivalents	57,839	96,085
Trading securities	9,597	7,857
Securities available-for-sale	515,121	498,897
Securities held-to-maturity	9,931	10,148
FHLB of New York stock, at cost	25,046	25,123
Net loans held-for-investment	3,114,659	2,943,489
Financial liabilities:
Deposits	2,836,979	2,713,587
Repurchase agreements and other borrowings	471,549	473,206
Advance payments by borrowers	14,798	12,331
Estimated Fair Value
Financial assets:
Cash and cash equivalents	57,839	96,085
Trading securities	9,597	7,857
Securities available-for-sale	515,121	498,897
Securities held-to-maturity	9,892	10,118
FHLB of New York stock, at cost	25,046	25,123
Net loans held-for-investment	3,157,829	2,970,438
Financial liabilities:
Deposits	2,839,666	2,720,176
Repurchase agreements and other borrowings	466,625	472,387
Advance payments by borrowers	14,798	12,331
Estimated Fair Value | Level 1
Financial assets:
Cash and cash equivalents	57,839	96,085
Trading securities	9,597	7,857
Securities available-for-sale	323	271
Securities held-to-maturity	0	0
FHLB of New York stock, at cost	0	0
Net loans held-for-investment	0	0
Financial liabilities:
Deposits	0	0
Repurchase agreements and other borrowings	0	0
Advance payments by borrowers	0	0
Estimated Fair Value | Level 2
Financial assets:
Cash and cash equivalents	0	0
Trading securities	0	0
Securities available-for-sale	514,798	498,626
Securities held-to-maturity	9,892	10,118
FHLB of New York stock, at cost	25,046	25,123
Net loans held-for-investment	0	0
Financial liabilities:
Deposits	2,839,666	2,720,176
Repurchase agreements and other borrowings	466,625	472,387
Advance payments by borrowers	14,798	12,331
Estimated Fair Value | Level 3
Financial assets:
Cash and cash equivalents	0	0
Trading securities	0	0
Securities available-for-sale	0	0
Securities held-to-maturity	0	0
FHLB of New York stock, at cost	0	0
Net loans held-for-investment	3,157,829	2,970,438
Financial liabilities:
Deposits	0	0
Repurchase agreements and other borrowings	0	0
Advance payments by borrowers	$ 0	$ 0

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income (loss)	$ 24,768	$ 26,130	$ 19,531
Basic weighted average shares outstanding (in shares)	45,325,445	44,374,389	42,285,712
Effect of non-vested restricted stock and stock options outstanding (in shares)	1,550,285	1,343,498	1,192,769
Weighted average shares outstanding-diluted (in shares)	46,875,730	45,717,887	43,478,481
Earnings per share-basic (usd per share)	$ 0.55	$ 0.59	$ 0.46
Earnings per share-diluted (usd per share)	$ 0.53	$ 0.57	$ 0.45
Anti-dilutive shares	334,927	777,733	2,679,507

Parent-only Financial Inform100

Parent-only Financial Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS:
Interest-earning deposits in other financial institutions	$ 40,393	$ 77,673
Other assets	32,900	44,563
Total assets	3,991,417	3,850,094
LIABILITIES AND STOCKHOLDERS’ EQUITY:
Total liabilities	3,352,540	3,228,898
Total stockholders' equity	638,877	621,196	$ 559,779	$ 593,928
Total liabilities and stockholders' equity	3,991,417	3,850,094
Parent Company
ASSETS:
Cash in Northfield Bank	20,080	8,953
Interest-earning deposits in other financial institutions	21	21
Investment in Northfield Bank	594,385	588,856
ESOP loan receivable	24,021	25,043
Other assets	1,185	118
Total assets	639,692	622,991
LIABILITIES AND STOCKHOLDERS’ EQUITY:
Total liabilities	815	1,795
Total stockholders' equity	638,877	621,196
Total liabilities and stockholders' equity	$ 639,692	$ 622,991

Parent-only Financial Inform101

Parent-only Financial Information - Condensed Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income tax expense									$ 26,978	$ 13,665	$ 11,975
Net income									24,768	26,130	19,531
Other comprehensive loss, net of tax									(227)	(1,346)	(2,221)
Comprehensive income									24,541	24,784	17,310
Parent Company
Interest on ESOP loan									939	913	875
Interest income on deposit in Northfield Bank									31	31	51
Gains (losses) on securities transactions, net									5	4	(4)
Undistributed earnings of Northfield Bank									24,887	26,303	19,718
Total income									25,862	27,251	20,640
Other expenses									872	936	891
Income tax expense	$ 15,686	$ 4,525	$ 3,807	$ 2,960	$ 4,273	$ 3,782	$ 3,681	$ 1,929	222	185	218
Total expense									1,094	1,121	1,109
Net income	$ (1,716)	$ 8,126	$ 8,410	$ 9,948	$ 8,198	$ 7,287	$ 6,985	$ 3,660	24,768	26,130	19,531
Other comprehensive loss, net of tax									(227)	(1,346)	(2,221)
Comprehensive income									$ 24,541	$ 24,784	$ 17,310

Parent-only Financial Inform102

Parent-only Financial Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income									$ 24,768	$ 26,130	$ 19,531
Adjustments to reconcile net income to net cash provided by operating activities:
(Increase) decrease in other assets									(3,689)	3,052	3,359
Cash flows from financing activities:
Exercise of stock options									100	120	158
Additional tax benefit on stock awards									0	1,512	122
Net increase (decrease) in cash and cash equivalents									(38,246)	44,232	(24,856)
Cash and cash equivalents at beginning of period				$ 96,085				$ 51,853	96,085	51,853	76,709
Cash and cash equivalents at end of period	$ 57,839				$ 96,085				57,839	96,085	51,853
Parent Company
Cash flows from operating activities:
Net income	(1,716)	$ 8,126	$ 8,410	9,948	8,198	$ 7,287	$ 6,985	3,660	24,768	26,130	19,531
Adjustments to reconcile net income to net cash provided by operating activities:
(Increase) decrease in other assets									(2,008)	(1,994)	(457)
(Gains) losses on securities transactions, net									(5)	(4)	4
(Decrease) increase in other liabilities									(980)	1,238	377
Undistributed earnings of Northfield Bank									(24,887)	(26,303)	(19,718)
Net cash used in operating activities									(3,112)	(933)	(263)
Cash flows from investing activities:
Cash consideration paid for business acquisition									0	(13,644)	0
Dividends from Northfield Bank									28,763	14,700	25,900
Net cash provided by investing activities									28,763	1,056	25,900
Cash flows from financing activities:
Principal payments on ESOP loan receivable									1,022	969	922
Purchase of treasury stock									0	(2,201)	(48,446)
Dividends paid									(15,646)	(14,074)	(12,184)
Exercise of stock options									100	120	158
Additional tax benefit on stock awards									0	1,512	122
Net cash used in financing activities									(14,524)	(13,674)	(59,428)
Net increase (decrease) in cash and cash equivalents									11,127	(13,551)	(33,791)
Cash and cash equivalents at beginning of period				$ 8,974				$ 22,525	8,974	22,525	56,316
Cash and cash equivalents at end of period	$ 20,101				$ 8,974				$ 20,101	$ 8,974	$ 22,525

Selected Quarterly Financial103

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income									$ 132,869	$ 124,972	$ 101,758
Interest expense									23,976	21,668	19,688
Net interest income									108,893	103,304	82,070
Provision for loan losses									1,411	635	353
Net interest income after provision for loan losses									107,482	102,669	81,717
Other income									11,642	10,072	7,898
Other expenses									67,378	72,946	58,109
Income before income tax expense									51,746	39,795	31,506
Income tax expense									26,978	13,665	11,975
Net income (loss)									$ 24,768	$ 26,130	$ 19,531
Net income per common share-basic (usd per share)									$ 0.55	$ 0.59	$ 0.46
Net income per common share-diluted (usd per share)									$ 0.53	$ 0.57	$ 0.45
Parent Company
Interest income	$ 34,615	$ 33,525	$ 32,660	$ 32,069	$ 32,110	$ 31,525	$ 31,168	$ 30,169
Interest expense	6,660	6,173	5,751	5,392	5,426	5,274	5,527	5,441
Net interest income	27,955	27,352	26,909	26,677	26,684	26,251	25,641	24,728
Provision for loan losses	40	488	511	372	280	472	14	(131)
Net interest income after provision for loan losses	27,915	26,864	26,398	26,305	26,404	25,779	25,627	24,859
Other income	2,443	2,615	2,437	4,147	2,643	2,667	2,533	2,229
Other expenses	16,388	16,828	16,618	17,544	16,576	17,377	17,494	21,499
Income before income tax expense	13,970	12,651	12,217	12,908	12,471	11,069	10,666	5,589
Income tax expense	15,686	4,525	3,807	2,960	4,273	3,782	3,681	1,929	$ 222	$ 185	$ 218
Net income (loss)	$ (1,716)	$ 8,126	$ 8,410	$ 9,948	$ 8,198	$ 7,287	$ 6,985	$ 3,660	$ 24,768	$ 26,130	$ 19,531
Net income per common share-basic (usd per share)	$ (0.04)	$ 0.18	$ 0.19	$ 0.22	$ 0.18	$ 0.16	$ 0.16	$ 0.08
Net income per common share-diluted (usd per share)	$ (0.04)	$ 0.17	$ 0.18	$ 0.21	$ 0.18	$ 0.16	$ 0.15	$ 0.08