Northfield Bancorp, Inc. (NFBK) 10-K 2 Mar 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 24, 2020	Jun. 30, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-35791
Entity Registrant Name	Northfield Bancorp, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	80-0882592
Entity Address, Address Line One	581 Main Street,
Entity Address, City or Town	Woodbridge,
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07095
City Area Code	732
Local Phone Number	499-7200
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	NFBK
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 669,416,040
Entity Common Stock, Shares Outstanding		49,188,347
Documents Incorporated by Reference	Certain portions of the registrant’s Definitive Proxy Statement (the “ 2020 Proxy Statement”) for the 2020 Annual Meeting of the Stockholders to be held May 20, 2020 , will be incorporated by reference in Part III. The 2020 Proxy Statement will be filed within 120 days of December 31, 2019 .
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0001493225
Current Fiscal Year End Date	--12-31

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
ASSETS:
Cash and due from banks	$ 15,409	$ 15,147
Interest-bearing deposits in other financial institutions	132,409	62,615
Total cash and cash equivalents	147,818	77,762
Trading securities	11,222	8,968
Debt securities available-for-sale, at estimated fair value	1,138,352	808,031
Debt securities held-to-maturity	8,762	9,505
Equity securities	3,341	1,280
Total Loans Receivable, net	2,987,067	2,678,877
Loans acquired	432,653	546,150
Purchased credit-impaired (PCI) loans held-for-investment	17,365	20,143
Loans held-for-investment, net	3,437,085	3,245,170
Allowance for loan losses	(28,707)	(27,497)
Net loans held-for-investment	3,408,378	3,217,673
Accrued interest receivable	14,609	12,959
Bank owned life insurance	153,459	154,135
Federal Home Loan Bank (FHLB) of New York stock, at cost	39,575	22,517
Operating lease right-of-use assets	39,504
Premises and equipment, net	25,659	25,605
Goodwill	38,411	38,411
Other assets	26,212	31,586
Total assets	5,055,302	4,408,432
LIABILITIES:
Deposits	3,408,233	3,286,512
Securities sold under agreements to repurchase	75,000	0
FHLB Advances and other borrowings	782,004	408,891
Operating lease liabilities	44,069
Advance payments by borrowers for taxes and insurance	20,045	18,007
Accrued expenses and other liabilities	30,098	28,583
Total liabilities	4,359,449	3,741,993
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, 2019 and 2018, 49,175,347 and 49,635,673 outstanding at December 31, 2019 and 2018, respectively	609	609
Additional paid-in-capital	548,486	546,219
Unallocated common stock held by employee stock ownership plan	(19,740)	(20,992)
Retained earnings	322,581	302,544
Accumulated other comprehensive income (loss)	4,699	(9,147)
Treasury stock at cost; 11,758,360 and 11,298,034 shares at December 31, 2019 and 2018, respectively	(160,782)	(152,794)
Total stockholders’ equity	695,853	666,439
Total liabilities and stockholders’ equity	$ 5,055,302	$ 4,408,432

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Debt securities held-to-maturity, at amortized cost	$ 8,886	$ 9,249
Preferred stock, par value (dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	60,933,707	60,933,707
Common stock, shares outstanding (in shares)	49,175,347	49,635,673
Treasury stock, shares (in shares)	11,758,360	11,298,034

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Loans	$ 136,133	$ 127,591	$ 120,340
Mortgage-backed securities	19,710	12,987	9,174
Other securities	6,331	4,112	1,310
FHLB of New York dividends	1,618	1,683	1,461
Deposits in other financial institutions	1,351	919	584
Total interest income	165,143	147,292	132,869
Interest expense:
Deposits	41,328	27,741	16,386
Borrowings	12,030	8,309	7,590
Total interest expense	53,358	36,050	23,976
Net interest income	111,785	111,242	108,893
Provision for loan losses	22	2,615	1,411
Net interest income after provision for loan losses	111,763	108,627	107,482
Non-interest income:
Fees and service charges for customer services	4,881	4,877	4,702
Income on bank owned life insurance	7,023	3,705	5,386
Gains on available-for-sale debt securities, net	514	178	169
Gains (losses) on trading securities, net	1,988	(879)	1,114
Other	402	246	271
Total non-interest income	14,808	8,127	11,642
Non-interest expense:
Compensation and employee benefits	39,571	34,802	38,237
Occupancy	13,676	12,096	11,270
Furniture and equipment	1,085	1,004	1,141
Data processing	5,679	5,011	4,585
Professional fees	3,545	3,482	2,774
Advertising	3,442	2,726	1,861
Federal Deposit Insurance Corporation (FDIC) insurance	563	1,065	1,064
Other	5,988	6,857	6,446
Total non-interest expense	73,549	67,043	67,378
Income before income tax expense	53,022	49,711	51,746
Income tax expense	12,787	9,632	26,978
Net income	$ 40,235	$ 40,079	$ 24,768
Net income per common share:
Basic (dollars per share)	$ 0.86	$ 0.87	$ 0.55
Diluted (dollars per share)	$ 0.85	$ 0.85	$ 0.53
Basic weighted average shares outstanding (in shares)	46,783,442	46,319,760	45,325,445
Diluted weighted average shares outstanding (in shares)	47,163,804	47,107,433	46,875,730
Net income	$ 40,235	$ 40,079	$ 24,768
Unrealized gains (losses) on debt securities available-for-sale:
Net unrealized holding gains (losses)	19,666	(5,203)	(283)
Less: reclassification adjustment for net gains included in net income	(514)	(178)	(169)
Net unrealized gains (losses)	19,152	(5,381)	(452)
Post-retirement benefits adjustment	77	240	74
Other comprehensive income (loss), before tax	19,229	(5,141)	(378)
Income tax (expense) benefit related to net unrealized holding gains (losses) on debt securities available-for-sale	(5,505)	1,462	113
Income tax benefit related to reclassification adjustment for gains included in net income	144	50	68
Income tax expense related to post-retirement benefits adjustment	(22)	(67)	(30)
Other comprehensive income (loss), net of tax	13,846	(3,696)	(227)
Comprehensive income	$ 54,081	$ 36,383	$ 24,541

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 (in shares) at Dec. 31, 2016		48,526,658
Beginning Balance at Dec. 31, 2016	$ 621,196	$ 609	$ 547,910	$ (23,466)	$ 268,226	$ (4,332)	$ (167,751)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	24,768				24,768
Other comprehensive loss, net of tax	(227)					(227)
Reclassification of tax effects resulting from the adoption of ASU No. 2018-02 | ASU 2018-02	0				892	(892)
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
Additional tax benefit on equity awards	0
Net issuance of restricted stock (in shares)		(58,447)
Net issuance of restricted stock	0		828				(828)
Exercise of stock options, net (in shares)		335,674
Exercise of stock options, net	100		(4,440)				4,540
Cash dividends declared	(15,646)				(15,646)
Ending Balance (in shares) at Dec. 31, 2017		48,803,885
Ending Balance at Dec. 31, 2017	638,877	$ 609	548,864	(22,244)	281,138	(5,451)	(164,039)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,079				40,079
Other comprehensive loss, net of tax	(3,696)					(3,696)
Employee Stock Ownership Plan (ESOP) shares allocated or committed to be released	2,337		1,085	1,252
Stock compensation expense	5,432		5,432
Net forfeitures of restricted stock (in shares)		10,040
Net forfeitures of restricted stock	$ 0		(133)				133
Exercise of stock options, net (in shares)	1,339,714	822,074
Exercise of stock options, net	$ 2,088		(9,029)				11,117
Cash dividends declared	(18,673)				(18,673)
Treasury stock (in shares)		(326)
Treasury stock	(5)						(5)
Ending Balance (in shares) at Dec. 31, 2018		49,635,673
Ending Balance at Dec. 31, 2018	666,439	$ 609	546,219	(20,992)	302,544	(9,147)	(152,794)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,235				40,235
Other comprehensive loss, net of tax	13,846					13,846
Employee Stock Ownership Plan (ESOP) shares allocated or committed to be released	2,340		1,088	1,252
Stock compensation expense	3,236		3,236
Net issuance of restricted stock (in shares)		(8,000)
Net issuance of restricted stock	$ 0		118				(118)
Exercise of stock options, net (in shares)	1,009,402	583,574
Exercise of stock options, net	$ 5,770		(2,175)				7,945
Cash dividends declared	(20,198)				(20,198)
Treasury stock (in shares)		(1,035,900)
Treasury stock	(15,815)						(15,815)
Ending Balance (in shares) at Dec. 31, 2019		49,175,347
Ending Balance at Dec. 31, 2019	$ 695,853	$ 609	$ 548,486	$ (19,740)	$ 322,581	$ 4,699	$ (160,782)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Dividends declared (dollars per share)	$ 0.43	$ 0.40	$ 0.34
Average cost of treasury stock (dollars per share)	$ 15.26	$ 16.85

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 40,235	$ 40,079	$ 24,768
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	22	2,615	1,411
ESOP and stock compensation expense	5,576	7,769	8,686
Depreciation expense	3,569	3,020	3,229
Amortization of premiums, and deferred loan costs, net of (accretion) of discounts, and deferred loan fees	4,344	2,441	2,000
Amortization of intangible assets	265	326	386
Amortization of operating lease right-of-use assets	5,069
Income on bank owned life insurance	(7,023)	(3,705)	(5,386)
Proceeds from sale of loans held-for-sale	0	0	494
Gains on available-for-sale debt securities, net	(514)	(178)	(169)
Gains (losses) on trading securities, net on securities, net	(1,988)	879	(1,114)
Net purchases of trading securities	(266)	(250)	(626)
Increase in accrued interest receivable	(1,650)	(2,246)	(999)
Decrease (increase) in other assets	2,679	3,563	(3,689)
Deferred taxes	(177)	(893)	15,193
Increase (decrease) in accrued expenses and other liabilities	1,011	(631)	(560)
Net cash (used in) provided by operating activities	51,152	52,789	43,624
Cash flows from investing activities:
Net increase in loans receivable	(147,507)	(69,270)	(110,177)
Purchase of loans	(44,918)	(37,593)	(64,116)
Purchase of FHLB of New York stock	(38,546)	(21,557)	(18,890)
Redemption of FHLB of New York stock	21,488	24,086	18,967
Purchases of debt securities available-for-sale	(635,898)	(451,174)	(137,631)
Purchases of equity securities	(2,061)
Principal payments and maturities on debt securities available-for-sale	243,374	118,485	114,416
Principal payments and maturities on debt securities held-to-maturity	709	403	200
Proceeds from sale of debt securities available-for-sale	79,255	32,115	4,975
Proceeds from sale of equity securities	0	0	966
Proceeds from bank owned life insurance	5,002	174	2,829
Proceeds from sale of other real estate owned	0	850	0
Purchases and improvements of premises and equipment	(3,623)	(2,879)	(2,065)
Net cash provided by investing activities	(522,725)	(406,360)	(190,526)
Cash flows from financing activities:
Net increase in deposits	121,721	449,533	123,392
Dividends paid	(20,198)	(18,673)	(15,646)
Exercise of stock options	5,770	2,088	100
Purchase of treasury stock	(15,815)	(5)	0
Increase in advance payments by borrowers for taxes and insurance	2,038	3,209	2,467
Repayments under capital lease obligations	(44)	(255)	(224)
Proceeds from securities sold under agreements to repurchase and other borrowings	1,206,659	397,312	441,570
Repayments related to securities sold under agreements to repurchase and other borrowings	(758,502)	(459,715)	(443,003)
Net cash used in financing activities	541,629	373,494	108,656
Net increase (decrease) in cash and cash equivalents	70,056	19,923	(38,246)
Cash and cash equivalents at beginning of period	77,762	57,839	96,085
Cash and cash equivalents at end of period	147,818	77,762	57,839
Supplemental cash flow information:
Interest	51,634	35,822	23,765
Income taxes	11,092	10,368	12,875
Non-cash transactions:
Loans charged-off / (recoveries), net	(1,189)	1,278	(154)
Transfers of originated loans held-for-investment to held-for-sale, at fair value	0	$ 0	$ 494
Initial recognition of operating lease right-of use assets	43,560
Initial recognition of operating lease liabilities	$ 47,328

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
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 debt securities held-to-maturity, debt securities available-for-sale, trading account securities or equity securities. Debt securities held-to-maturity are those that management has the positive intent and ability to hold until maturity. Debt 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. Debt securities available-for-sale represents all securities not classified as either held-to-maturity, trading, or equity. Debt 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, using quoted prices in active markets, with unrealized holding gains and losses reported as a component of gain (loss) on securities, net in non-interest income. Equity securities with readily determinable fair values are stated at fair value with unrealized gains and losses reported as a component of gain (loss) on securities, net in non-interest income. Equity securities without readily determinable fair values are recorded at net asset value less any impairment, if any. 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 estimated costs 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 consecutive 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 estimated 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 at least 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, 2019 and 2018 . (g) Operating Leases During the normal course of business, the Company enters into agreements, and at inception it determines if a particular agreement is a lease. The Company's operating lease agreements relate primarily to its corporate offices and bank branch offices. The agreements are recorded as operating lease right-of-use assets and operating lease liabilities on the consolidated balance sheets. Operating lease right of use assets and operating lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term, and represent the right to use an underlying asset for the lease term and the obligation to make lease payments arising from the lease. As the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate in determining the present value of lease payments. The Company's lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the term of the lease. (h) 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. (i) 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. (j) 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, 2019 , 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, 2019 , the carrying value of goodwill totaled $38.4 million . The Company performed its annual goodwill impairment test, as of December 31, 2019 , 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. (k) 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. (l) 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 estimated costs to sell. (m) 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. (n) Comprehensive Income (Loss) Comprehensive income (loss) includes net income and the change in unrealized holding gains and losses on debt 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. (o) 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. 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 Company accounts for forfeitures as they occur. The Bank has a 401(k) plan covering substantially all employees. Contributions to the plan are expensed as incurred. (p) 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. (q) 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 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 was applied prospectively upon adoption. When applying the treasury stock method for the years ended December 31, 2018 and 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 year ended December 31, 2016, 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, 2019 , 2018 , and 2017 , there were 380,362 , 787,673 , and 1,550,285 dilutive shares outstanding, respectively. (r) 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. (s) Advertising costs Advertising costs are expensed in the period they are incurred. (t) Derivatives During the fourth quarter of 2019, the Company began offering interest rate swaps to certain qualified commercial borrowers. These interest rate swaps result from a service provided to certain qualifying borrowers in a loan-related transaction and, therefore, are not used to manage interest rate risk in the Company’s assets or liabilities. As such, all changes in the fair value of these derivatives are recognized directly in earnings. The Company records all derivatives on the Consolidated Balance Sheets at fair value. (u) Recent Accounting Pronouncements Adopted ASU No. 2016-02. In February 2016, the FASB issued ASU No. 2016-02, Leases ( “ Topic 842 ” ) , which requires all lessees to recognize a lease liability and a right-of-use asset, measured at the present value of the future minimum lease payments, at the lease commencement date for leases classified as operating leases as well as finance leases. Under this guidance, lessor accounting is largely unchanged. This ASU became effective for annual and interim periods for the Company on January 1, 2019. The Company adopted the standard by applying the alternative transition method whereby comparative periods were not restated, and no cumulative effect adjustment to the opening balance of retained earnings was recognized as of January 1, 2019. The Company also elected the ASU’s package of three practical expedients, which allowed the Company to forego a reassessment of (i) whether any expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases and (iii) the initial direct costs for any existing leases. The Company also elected not to apply the recognition requirements of the ASU to any short-term leases (as defined by related accounting guidance) and will account for lease and non-lease components separately because such amounts are readily determinable under most lease contracts. The adoption of this standard resulted in the Company recognizing operating lease right-of-use assets and related operating lease liabilities totaling $43.6 million and $47.3 million respectively, as of January 1, 2019 . The adoption of this ASU did not have a material impact on the Company’s consolidated results of operations. See Note 18, Leases, for further disclosures. ASU No. 2017-08. In March 2017, the FASB issued ASU No. 2017-08, Receivables-Nonrefundable

Debt Securities Available-for-S

Debt Securities Available-for-Sale	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Debt Securities Available-for-Sale	Debt Securities Available-for-Sale The following is a comparative summary of mortgage-backed securities and other debt securities available-for-sale at December 31, 2019 and 2018 (in thousands): 2019 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: Government sponsored enterprises (GSE) $ 324,080 $ 6,081 $ 754 $ 329,407 Real estate mortgage investment conduits (REMICs): GSE 643,816 2,076 2,225 643,667 Non-GSE 53 — — 53 967,949 8,157 2,979 973,127 Other debt securities: Municipal bonds 296 3 — 299 Corporate bonds 163,725 1,214 13 164,926 164,021 1,217 13 165,225 Total debt securities available-for-sale $ 1,131,970 $ 9,374 $ 2,992 $ 1,138,352 2018 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: GSE $ 317,530 $ 800 $ 3,542 $ 314,788 REMICs: GSE 258,050 92 7,979 250,163 Non-GSE 59 — 1 58 575,639 892 11,522 565,009 Other debt securities: Municipal bonds 270 3 — 273 Corporate bonds 244,892 72 2,215 242,749 245,162 75 2,215 243,022 Total debt securities available-for-sale $ 820,801 $ 967 $ 13,737 $ 808,031 The following is a summary of the expected maturity distribution of debt securities available-for-sale other than mortgage-backed securities at December 31, 2019 (in thousands): Available-for-sale Amortized cost Estimated fair value Due in one year or less $ 75,115 $ 75,353 Due after one year through five years 88,906 89,872 $ 164,021 $ 165,225 Contractual maturities for mortgage-backed securities are not included above, as expected maturities on mortgage-backed securities may 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, 2019 , and December 31, 2018 , debt securities available-for-sale with a carrying value of $730.9 million and $492.4 million , respectively, were pledged to secure repurchase agreements and deposits. See Note 8 - "Borrowings" for further discussion regarding securities pledged or encumbered for borrowings. For the year ended December 31, 2019 , the Company had gross proceeds of $79.3 million on sales of securities available-for-sale with gross realized gains of $514,000 and no gross realized losses. For the year ended December 31, 2018 , the Company had gross proceeds of $32.1 million on sales of securities available-for-sale with gross realized gains of $183,000 and gross realized losses of $5,000 . For the year ended December 31, 2017 , the Company had gross proceeds of $5.0 million on sales of securities available-for-sale with gross realized gains of $173,000 and gross realized losses of $4,000 . The Company recognized net gains of $2.0 million on its trading securities portfolio during the year ended December 31, 2019 , net losses of $879,000 during the year ended 2018 , and net gains of $1.1 million during the year ended 2017 . 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. Gross unrealized losses on mortgage-backed securities and other debt 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, 2019 and 2018 , were as follows (in thousands): December 31, 2019 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 $ 25 $ 3,404 $ 729 $ 55,184 $ 754 $ 58,588 REMICs: GSE 950 197,634 1,275 54,555 2,225 252,189 Non-GSE — — — 53 — 53 Other debt securities: Corporate bonds — — 13 15,586 13 15,586 Total $ 975 $ 201,038 $ 2,017 $ 125,378 $ 2,992 $ 326,416 December 31, 2018 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 $ 404 $ 82,781 $ 3,138 $ 100,109 $ 3,542 $ 182,890 REMICs: GSE 269 46,921 7,710 181,512 7,979 228,433 Non-GSE — — 1 58 1 58 Other debt securities: Corporate bonds 1,703 173,219 512 25,675 2,215 198,894 Total $ 2,376 $ 302,921 $ 11,361 $ 307,354 $ 13,737 $ 610,275 The Company held 28 pass-through mortgage-backed securities issued or guaranteed by GSEs, 20 REMIC mortgage-backed securities issued or guaranteed by GSEs, one REMIC mortgage-backed security not issued or guaranteed by GSEs, and four corporate bonds that were in a continuous unrealized loss position of greater than twelve months at December 31, 2019 . There were three pass-through mortgage-backed securities issued or guaranteed by GSEs, and 23 REMIC mortgage-backed securities issued or guaranteed by GSEs. 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, 2019 . The declines in fair 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 debt securities available-for-sale 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, which may result in other-than-temporary impairment in the future. The Company did no t recognize any other-than-temporary impairment charges in earnings on debt securities available-for sale during the years ended December 31, 2019 , 2018 and 2017 Equity Securities At December 31, 2019 and December 31, 2018 , equity securities totaled $3.3 million and $1.3 million , respectively. Equity securities consist of money market mutual funds, recorded at fair value of $250,000 and $237,000 , at December 31, 2019 and December 31, 2018 , respectively, and an investment in a private Small Business Administration (“SBA”) Loan Fund recorded at net asset value of $3.1 million and $1.0 million at December 31, 2019 and December 31, 2018

Debt Securities Held-to-Maturit

Debt Securities Held-to-Maturity	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Debt Securities Held-to-Maturity	Debt Securities Held-to-Maturity The following is a summary of mortgage-backed securities held-to-maturity at December 31, 2019 and 2018 (in thousands): 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 8,762 $ 129 $ 5 $ 8,886 Total securities held-to-maturity $ 8,762 $ 129 $ 5 $ 8,886 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 9,505 $ — $ 256 $ 9,249 Total securities held-to-maturity $ 9,505 $ — $ 256 $ 9,249 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, 2019 , 2018 and 2017 . At December 31, 2019 , and December 31, 2018 , debt securities held-to-maturity with a carrying value of $7.4 million and $6.5 million , respectively, were pledged to secure repurchase agreements and deposits. See Note 8 - "Borrowings" for further discussion regarding securities pledged or encumbered for borrowings 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, 2019 and 2018 , were as follows (in thousands): December 31, 2019 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 $ — $ — $ 5 $ 378 $ 5 $ 378 Total $ — $ — $ 5 $ 378 $ 5 $ 378 December 31, 2018 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 $ 34 $ 2,133 $ 222 $ 7,116 $ 256 $ 9,249 Total $ 34 $ 2,133 $ 222 $ 7,116 $ 256 $ 9,249 The Company held one pass-through mortgage-backed debt security held-to-maturity, issued or guaranteed by GSEs, that was in a continuous unrealized loss position of greater than twelve months at December 31, 2019. Management evaluated this security and concluded that the decline in value relates to the general interest rate environment and is considered temporary. The security 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 security before the recovery of its amortized cost basis or, if necessary, maturity. The fair values of our debt securities held-to-maturity 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. 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, 2019 , 2018 and 2017

Equity Securities

Equity Securities	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Equity Securities	Debt Securities Available-for-Sale The following is a comparative summary of mortgage-backed securities and other debt securities available-for-sale at December 31, 2019 and 2018 (in thousands): 2019 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: Government sponsored enterprises (GSE) $ 324,080 $ 6,081 $ 754 $ 329,407 Real estate mortgage investment conduits (REMICs): GSE 643,816 2,076 2,225 643,667 Non-GSE 53 — — 53 967,949 8,157 2,979 973,127 Other debt securities: Municipal bonds 296 3 — 299 Corporate bonds 163,725 1,214 13 164,926 164,021 1,217 13 165,225 Total debt securities available-for-sale $ 1,131,970 $ 9,374 $ 2,992 $ 1,138,352 2018 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: GSE $ 317,530 $ 800 $ 3,542 $ 314,788 REMICs: GSE 258,050 92 7,979 250,163 Non-GSE 59 — 1 58 575,639 892 11,522 565,009 Other debt securities: Municipal bonds 270 3 — 273 Corporate bonds 244,892 72 2,215 242,749 245,162 75 2,215 243,022 Total debt securities available-for-sale $ 820,801 $ 967 $ 13,737 $ 808,031 The following is a summary of the expected maturity distribution of debt securities available-for-sale other than mortgage-backed securities at December 31, 2019 (in thousands): Available-for-sale Amortized cost Estimated fair value Due in one year or less $ 75,115 $ 75,353 Due after one year through five years 88,906 89,872 $ 164,021 $ 165,225 Contractual maturities for mortgage-backed securities are not included above, as expected maturities on mortgage-backed securities may 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, 2019 , and December 31, 2018 , debt securities available-for-sale with a carrying value of $730.9 million and $492.4 million , respectively, were pledged to secure repurchase agreements and deposits. See Note 8 - "Borrowings" for further discussion regarding securities pledged or encumbered for borrowings. For the year ended December 31, 2019 , the Company had gross proceeds of $79.3 million on sales of securities available-for-sale with gross realized gains of $514,000 and no gross realized losses. For the year ended December 31, 2018 , the Company had gross proceeds of $32.1 million on sales of securities available-for-sale with gross realized gains of $183,000 and gross realized losses of $5,000 . For the year ended December 31, 2017 , the Company had gross proceeds of $5.0 million on sales of securities available-for-sale with gross realized gains of $173,000 and gross realized losses of $4,000 . The Company recognized net gains of $2.0 million on its trading securities portfolio during the year ended December 31, 2019 , net losses of $879,000 during the year ended 2018 , and net gains of $1.1 million during the year ended 2017 . 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. Gross unrealized losses on mortgage-backed securities and other debt 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, 2019 and 2018 , were as follows (in thousands): December 31, 2019 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 $ 25 $ 3,404 $ 729 $ 55,184 $ 754 $ 58,588 REMICs: GSE 950 197,634 1,275 54,555 2,225 252,189 Non-GSE — — — 53 — 53 Other debt securities: Corporate bonds — — 13 15,586 13 15,586 Total $ 975 $ 201,038 $ 2,017 $ 125,378 $ 2,992 $ 326,416 December 31, 2018 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 $ 404 $ 82,781 $ 3,138 $ 100,109 $ 3,542 $ 182,890 REMICs: GSE 269 46,921 7,710 181,512 7,979 228,433 Non-GSE — — 1 58 1 58 Other debt securities: Corporate bonds 1,703 173,219 512 25,675 2,215 198,894 Total $ 2,376 $ 302,921 $ 11,361 $ 307,354 $ 13,737 $ 610,275 The Company held 28 pass-through mortgage-backed securities issued or guaranteed by GSEs, 20 REMIC mortgage-backed securities issued or guaranteed by GSEs, one REMIC mortgage-backed security not issued or guaranteed by GSEs, and four corporate bonds that were in a continuous unrealized loss position of greater than twelve months at December 31, 2019 . There were three pass-through mortgage-backed securities issued or guaranteed by GSEs, and 23 REMIC mortgage-backed securities issued or guaranteed by GSEs. 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, 2019 . The declines in fair 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 debt securities available-for-sale 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, which may result in other-than-temporary impairment in the future. The Company did no t recognize any other-than-temporary impairment charges in earnings on debt securities available-for sale during the years ended December 31, 2019 , 2018 and 2017 Equity Securities At December 31, 2019 and December 31, 2018 , equity securities totaled $3.3 million and $1.3 million , respectively. Equity securities consist of money market mutual funds, recorded at fair value of $250,000 and $237,000 , at December 31, 2019 and December 31, 2018 , respectively, and an investment in a private Small Business Administration (“SBA”) Loan Fund recorded at net asset value of $3.1 million and $1.0 million at December 31, 2019 and December 31, 2018

Loans

Loans	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Loans	Loans Loans held-for-investment, net, consists of the following (in thousands): December 31, 2019 2018 Originated loans: Real estate loans: Multifamily $ 2,196,407 $ 1,930,535 Commercial mortgage 528,681 499,311 One-to-four family residential mortgage 83,742 91,371 Home equity and lines of credit 84,928 78,593 Construction and land 38,284 26,552 Total real estate loans 2,932,042 2,626,362 Commercial and industrial loans 45,328 44,104 Other loans 2,083 1,519 Total commercial and industrial and other loans 47,411 45,623 Deferred loan cost, net 7,614 6,892 Originated loans held-for-investment, net 2,987,067 2,678,877 PCI Loans 17,365 20,143 Loans acquired: One-to-four family residential mortgage 187,975 225,877 Multifamily 108,417 145,485 Commercial mortgage 113,027 133,263 Home equity and lines of credit 12,008 17,583 Construction and land 2,537 12,003 Total acquired real estate loans 423,964 534,211 Commercial and industrial loans 8,689 11,933 Other loans — 6 Total loans acquired 432,653 546,150 Loans held for investment, net 3,437,085 3,245,170 Allowance for loan losses (28,707 ) (27,497 ) Net loans held-for-investment $ 3,408,378 $ 3,217,673 The Company had no loans held-for-sale at December 31, 2019 , or December 31, 2018 . PCI loans totaled $17.4 million at December 31, 2019 , as compared to $ $20.1 million at December 31, 2018 . 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, 2019 , PCI loans consisted of approximately 29% commercial real estate loans and 42% commercial and industrial loans, with the remaining balance in residential and home equity loans. At December 31, 2018 , 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. The following details the accretable yield (in thousands): For The Year Ended December 31, 2019 2018 Balance at the beginning of year $ 21,846 $ 24,502 Accretion into interest income (4,142 ) (4,176 ) Net reclassification from non-accretable difference (1) (618 ) 1,520 Balance at end of year $ 17,086 $ 21,846 (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 estimated costs 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, 2019 and 2018 , the allowance for loan losses related to loans held-for-investment (excluding PCI loans) consisted primarily of the following two elements: (1) Allowances for loans individually evaluated for impairment 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 estimated 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) Allowances for loans collectively evaluated for impairment 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, and internal credit risk ratings. We apply an estimated loss rate to each loan group comprised of historical quantitative loss rates and qualitative factors. The quantitative loss rates are based on our historical net loss rates (using a look-back period and loss emergence periods). Qualitative factors to such loss rates are made when internal and external factors are identified which may not be fully captured in our historical quantitative net loss rates such as: • 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 periods are estimated from the date of the loss event to the actual recognition of the loss (typically the first charge-off), and are determined based upon a study of the Company's past loss experience by loan groups. The evaluation for loan losses 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. 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 individually evaluated and collectively evaluated for impairment components of 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. At least 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, 2019 , 2018 , and 2017 follows (in thousands): Year Ended December 31, 2019 2018 2017 Balance at beginning of year $ 27,497 $ 26,160 $ 24,595 Provision for loan losses 22 2,615 1,411 Recoveries 2,175 112 556 Charge-offs (987 ) (1,390 ) (402 ) Balance at end of year $ 28,707 $ 27,497 $ 26,160 The following table sets forth activity in our allowance for loan losses, by loan type, for the years ended December 31, 2019 and 2018 . 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): Year Ended December 31, 2019 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 5,630 $ 342 $ 463 $ 18,084 $ 291 $ 1,569 $ 108 $ 26,487 $ 1,010 $ — $ 27,497 Charge-offs (520 ) — — — — (100 ) (123 ) (743 ) — (244 ) (987 ) Recoveries 98 72 — 1,818 — 20 1 2,009 — 166 2,175 Provisions (credit) (452 ) (234 ) 73 301 26 151 165 30 (221 ) 213 22 Ending Balance $ 4,756 $ 180 $ 536 $ 20,203 $ 317 $ 1,640 $ 151 $ 27,783 $ 789 $ 135 $ 28,707 Ending balance: individually evaluated for impairment $ — $ — $ — $ — $ 3 $ 4 $ — $ 7 $ — $ 135 $ 142 Ending balance: collectively evaluated for impairment $ 4,756 $ 180 $ 536 $ 20,203 $ 314 $ 1,636 $ 151 $ 27,776 $ 789 $ — $ 28,565 Loans, net: Ending Balance $ 529,287 $ 85,355 $ 38,303 $ 2,199,734 $ 86,848 $ 45,456 $ 2,084 $ 2,987,067 $ 17,365 $ 432,653 $ 3,437,085 Ending balance: individually evaluated for impairment $ 13,226 $ 1,841 $ — $ 997 $ 55 $ 58 $ — $ 16,177 $ — $ 4,780 $ 20,957 Ending balance: collectively evaluated for impairment $ 516,061 $ 83,514 $ 38,303 $ 2,198,737 $ 86,793 $ 45,398 $ 2,084 $ 2,970,890 $ 17,365 $ 427,873 $ 3,416,128 Year Ended December 31, 2018 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 5,196 $ 503 $ 610 $ 17,374 $ 122 $ 1,273 $ 94 $ 25,172 $ 951 $ 37 $ 26,160 Charge-offs (1,256 ) (3 ) — — (60 ) (70 ) — (1,389 ) — (1 ) (1,390 ) Recoveries 49 4 — 26 — 20 — 99 — 13 112 Provisions (credit) 1,641 (162 ) (147 ) 684 229 346 14 2,605 59 (49 ) 2,615 Ending Balance $ 5,630 $ 342 $ 463 $ 18,084 $ 291 $ 1,569 $ 108 $ 26,487 $ 1,010 $ — $ 27,497 Ending balance: individually evaluated for impairment $ — $ 18 $ — $ — $ 5 $ 3 $ — $ 26 $ — $ — $ 26 Ending balance: collectively evaluated for impairment $ 5,630 $ 324 $ 463 $ 18,084 $ 286 $ 1,566 $ 108 $ 26,461 $ 1,010 $ — $ 27,471 Loans, net: Ending Balance $ 499,860 $ 92,433 $ 26,613 $ 1,933,946 $ 80,315 $ 44,190 $ 1,520 $ 2,678,877 $ 20,143 $ 546,150 $ 3,245,170 Ending balance: individually evaluated for impairment $ 15,252 $ 1,893 $ — $ 1,268 $ 61 $ 73 $ — $ 18,547 $ — $ 3,782 $ 22,329 Ending balance: collectively evaluated for impairment $ 484,608 $ 90,540 $ 26,613 $ 1,932,678 $ 80,254 $ 44,117 $ 1,520 $ 2,660,330 $ 20,143 $ 542,368 $ 3,222,841 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 credit 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 credit 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, 2019 and 2018 (in thousands): At December 31, 2019 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 $ 232,950 $ 1,960,984 $ 79,485 $ 440,065 $ 52,886 $ 29,967 $ 38,303 $ 86,547 $ 45,075 $ 2,084 $ 2,968,346 Special Mention — 296 370 1,092 777 — — 14 301 — 2,850 Substandard 301 5,203 — 8,275 1,397 328 — 287 80 — 15,871 Originated loans held-for-investment, net $ 233,251 $ 1,966,483 $ 79,855 $ 449,432 $ 55,060 $ 30,295 $ 38,303 $ 86,848 $ 45,456 $ 2,084 $ 2,987,067 At December 31, 2018 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 $ 170,832 $ 1,756,882 $ 78,917 $ 409,155 $ 54,912 $ 34,808 $ 26,613 $ 80,077 $ 43,640 $ 1,520 $ 2,657,356 Special Mention — 613 395 1,137 747 — — 27 430 — 3,349 Substandard — 5,619 — 10,256 1,406 560 — 211 120 — 18,172 Originated loans held-for-investment, net $ 170,832 $ 1,763,114 $ 79,312 $ 420,548 $ 57,065 $ 35,368 $ 26,613 $ 80,315 $ 44,190 $ 1,520 $ 2,678,877 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 non-accrual loans was $9.4 million and $9.2 million at December 31, 2019 , and December 31, 2018 , 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 $6.8 million and $5.9 million at December 31, 2019 , and December 31, 2018 , 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 $2.6 million at December 31, 2019 , and $3.2 million at December 31, 2018 . There was no loans held-for-sale at December 31, 2019 , or December 31, 2018 . Loans past due 90 days or more and still accruing interest were $518,000 and $33,000 at December 31, 2019 , and December 31, 2018 , 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, 2019 and 2018 (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, 2019 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 $ — $ — $ 2,416 $ 2,416 $ — $ 2,416 Total commercial — — 2,416 2,416 — 2,416 One-to-four family residential LTV < 60% Substandard — — 493 493 114 607 Total — — 493 493 114 607 LTV => 60% Substandard — 29 — 29 — 29 Total one-to-four family residential — 29 493 522 114 636 Construction and land Home equity and lines of credit Substandard — 67 89 156 — 156 Total home equity and lines of credit — 67 89 156 — 156 Total non-performing loans held-for-investment, originated — 96 2,998 3,094 114 3,208 Loans acquired: Real Estate Loans: Commercial LTV < 35% Substandard 79 — 188 267 66 333 LTV => 35% Substandard 3,530 — 1,709 5,239 187 5,426 Total commercial 3,609 — 1,897 5,506 253 5,759 One-to-four family residential LTV < 60% Substandard 190 — 85 275 151 426 Total 190 — 85 275 151 426 LTV => 60% Substandard — — 93 93 — 93 Total one-to-four family residential 190 — 178 368 151 519 Multifamily LTV < 35% Substandard 40 — — 40 — 40 LTV => 35% Substandard — 397 — 397 — 397 Total multifamily 40 397 — 437 — 437 Home equity and lines of credit Substandard — — 28 28 — 28 Total home equity and lines of credit — — 28 28 — 28 Total non-performing loans acquired 3,839 397 2,103 6,339 404 6,743 Total non-performing loans $ 3,839 $ 493 $ 5,101 $ 9,433 $ 518 $ 9,951 At December 31, 2018 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 $ — $ 287 $ 2,588 $ 2,875 $ — $ 2,875 Total commercial — 287 2,588 2,875 — 2,875 One-to-four family residential LTV < 60% Substandard — 432 77 509 — 509 LTV => 60% Substandard — 32 — 32 — 32 Total one-to-four family residential — 464 77 541 — 541 Home equity and lines of credit Substandard 75 — — 75 — 75 Total home equity and lines of credit 75 — — 75 — 75 Commercial and industrial loans Substandard — — 25 25 — 25 Total commercial and industrial loans — — 25 25 — 25 Total non-performing loans held-for-investment, originated 75 751 2,690 3,516 — 3,516 Loans acquired: Real Estate Loans: Commercial LTV < 35% Substandard 87 — 194 281 — 281 LTV => 35% Substandard — 764 3,371 4,135 — 4,135 Total commercial 87 764 3,565 4,416 — 4,416 One-to-four family residential LTV < 60% Substandard — 199 169 368 6 374 LTV => 60% Substandard 126 — 93 219 27 246 Total one-to-four family residential 126 199 262 587 33 620 Multifamily LTV < 35% Substandard 152 — — 152 — 152 LTV => 35% Substandard — 414 — 414 — 414 Total multifamily 152 414 — 566 — 566 Home equity and lines of credit Substandard — — 77 77 — 77 Total home equity and lines of credit — — 77 77 — 77 Total non-performing loans acquired 365 1,377 3,904 5,646 33 5,679 Total non-performing loans $ 440 $ 2,128 $ 6,594 $ 9,162 $ 33 $ 9,195 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, 2019 and 2018 (in thousands): December 31, 2019 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 $ 79,383 $ 102 $ 79,485 $ — $ 79,485 Special Mention 370 — 370 — 370 Total 79,753 102 79,855 — 79,855 LTV => 35% Pass 439,253 812 440,065 — 440,065 Special Mention 1,092 — 1,092 — 1,092 Substandard 5,228 631 5,859 2,416 8,275 Total 445,573 1,443 447,016 2,416 449,432 Total commercial 525,326 1,545 526,871 2,416 529,287 One-to-four family residential LTV < 60% Pass 52,757 129 52,886 — 52,886 Special Mention — 777 777 — 777 Substandard 790 — 790 607 1,397 Total 53,547 906 54,453 607 55,060 LTV => 60% Pass 29,741 226 29,967 — 29,967 Substandard 299 — 299 29 328 Total 30,040 226 30,266 29 30,295 Total one-to-four family residential 83,587 1,132 84,719 636 85,355 Construction and land Pass 38,156 147 38,303 — 38,303 Total construction and land 38,156 147 38,303 — 38,303 Multifamily LTV < 35% Pass 232,658 292 232,950 — 232,950 Substandard 301 — 301 — 301 Total 232,959 292 233,251 — 233,251 LTV= > 35% Pass 1,960,729 255 1,960,984 — 1,960,984 Special Mention 296 — 296 — 296 Substandard 5,203 — 5,203 — 5,203 Total 1,966,228 255 1,966,483 — 1,966,483 Total multifamily 2,199,187 547 2,199,734 — 2,199,734 Home equity and lines of credit Pass 86,380 167 86,547 — 86,547 Special Mention 14 — 14 — 14 Substandard 131 — 131 156 287 Total home equity and lines of credit 86,525 167 86,692 156 86,848 Commercial and industrial loans Pass 44,886 189 45,075 — 45,075 Special Mention 301 — 301 — 301 Substandard 80 — 80 — 80 Total commercial and industrial loans 45,267 189 45,456 — 45,456 December 31, 2019 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Other loans Pass 2,058 26 2,084 — 2,084 Total other loans 2,058 26 2,084 — 2,084 Total originated loans held-for-investment 2,980,106 3,753 2,983,859 3,208 2,987,067 Acquired loans: One-to-four family residential LTV < 60% Pass 172,882 73 172,955 — 172,955 Special Mention — 385 385 — 385 Substandard — — — 426 426 Total 172,882 458 173,340 426 173,766 LTV => 60% Pass 14,116 — 14,116 — 14,116 Substandard — — — 93 93 Total 14,116 — 14,116 93 14,209 Total one-to-four family residential 186,998 458 187,456 519 187,975 Commercial LTV < 35% Pass 35,173 287 35,460 — 35,460 Special Mention 994 194 1,188 — 1,188 Substandard 369 — 369 334 703 Total 36,536 481 37,017 334 37,351 LTV => 35% Pass 60,311 — 60,311 — 60,311 Special Mention 134 464 598 — 598 Substandard 6,382 2,960 9,342 5,425 14,767 Total 66,827 3,424 70,251 5,425 75,676 Total commercial 103,363 3,905 107,268 5,759 113,027 Construction and land Pass 2,537 — 2,537 — 2,537 Total construction and land 2,537 — 2,537 — 2,537 Multifamily LTV < 35% Pass 105,327 — 105,327 — 105,327 Substandard — — — 40 40 Total 105,327 — 105,327 40 105,367 LTV => 35% Pass 2,653 — 2,653 — 2,653 Substandard — — — 397 397 Total 2,653 — 2,653 397 3,050 Total multifamily 107,980 — 107,980 437 108,417 Home equity and lines of credit Pass 11,842 50 11,892 — 11,892 Substandard 88 — 88 28 116 Total home equity and lines of credit 11,930 50 11,980 28 12,008 Commercial and industrial Pass 8,649 40 8,689 — 8,689 Total commercial and industrial 8,649 40 8,689 — 8,689 Other — — — — — Total loans acquired 421,457 4,453 425,910 6,743 432,653 $ 3,401,563 $ 8,206 $ 3,409,769 $ 9,951 $ 3,419,720 December 31, 2018 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 $ 78,699 $ 218 $ 78,917 $ — $ 78,917 Special Mention — 395 395 — 395 Total 78,699 613 79,312 — 79,312 LTV => 35% Pass 408,830 325 409,155 — 409,155 Special Mention 1,137 — 1,137 — 1,137 Substandard 7,381 — 7,381 2,875 10,256 Total 417,348 325 417,673 2,875 420,548 Total commercial 496,047 938 496,985 2,875 499,860 One-to-four family residential LTV < 60% Pass 54,576 336 54,912 — 54,912 Special Mention — 747 747 — 747 Substandard 896 — 896 510 1,406 Total 55,472 1,083 56,555 510 57,065 LTV => 60% Pass 34,576 232 34,808 — 34,808 Substandard 528 — 528 32 560 Total 35,104 232 35,336 32 35,368 Total one-to-four family residential 90,576 1,315 91,891 542 92,433 Construction and land Pass 26,613 — 26,613 — 26,613 Total construction and land 26,613 — 26,613 — 26,613 Multifamily LTV < 35% Pass 170,534 298 170,832 — 170,832 Total 170,534 298 170,832 — 170,832 LTV => 35% Pass 1,756,443 439 1,756,882 — 1,756,882 Special Mention 613 — 613 — 613 Substandard 4,390 1,229 5,619 — 5,619 Total 1,761,446 1,668 1,763,114 — 1,763,114 Total multifamily 1,931,980 1,966 1,933,946 — 1,933,946 Home equity and lines of credit Pass 80,077 — 80,077 — 80,077 Special Mention 27 — 27 — 27 Substandard 137 — 137 74 211 Total home equity and lines of credit 80,241 — 80,241 74 80,315 Commercial and industrial loans Pass 43,640 — 43,640 — 43,640 Special Mention 430 — 430 — 430 Substandard 95 — 95 25 120 Total Commercial and industrial loans 44,165 — 44,165 25 44,190 Other loans Pass 1,518 2 1,520 — 1,520 Total other loans 1,518 2 1,520 — 1,520 Total originated loans held-for-investment 2,671,140 4,221 2,675,361 3,516 2,678,877 December 31, 2018 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 202,471 2,799 205,270 — 205,270 Special Mention 415 — 415 — 415 Substandard 62 6 68 374 442 Total 202,948 2,805 205,753 374 206,127 LTV => 60% Pass 19,504 — 19,504 — 19,504 Substandard — — — 246 246 Total 19,504 — 19,504 246 19,750 Total one-to-four family residential 222,452 2,805 225,257 620 225,877 Commercial LTV < 35% Pass 41,071 — 41,071 — 41,071 Special Mention 1,079 — 1,079 — 1,079 Substandard 1,185 151 1,336 281 1,617 Total 43,335 151 43,486 281 43,767 LTV => 35% Pass 73,986 749 74,735 — 74,735 Special Mention 4,315 128 4,443 — 4,443 Substandard 5,772 411 6,183 4,135 10,318 Total 84,073 1,288 85,361 4,135 89,496 Total commercial 127,408 1,439 128,847 4,416 133,263 Construction and land Substandard 12,003 — 12,003 — 12,003 Total construction and land 12,003 — 12,003 — 12,003 Multifamily LTV < 35% Pass 137,141 — 137,141 — 137,141 Special Mention — 52 52 — 52 Substandard — — — 152 152 Total 137,141 52 137,193 152 137,345 LTV => 35% Pass 7,726 — 7,726 — 7,726 Special Mention — — — 414 414 Total 7,726 — 7,726 414 8,140 Total multifamily 144,867 52 144,919 566 145,485 Home equity and lines of credit Pass 17,427 — 17,427 — 17,427 Substandard 79 — 79 77 156 Total home equity and lines of credit 17,506 — 17,506 77 17,583 Commercial and industrial loans Pass 11,888 45 11,933 — 11,933 Total Commercial and industrial loans 11,888 45 11,933 — 11,933 Other loans Pass 6 — 6 — 6 Total loans acquired 536,130 4,341 540,471 5,679 546,150 $ 3,207,270 $ 8,562 $ 3,215,832 $ 9,195 $ 3,225,027 The following table summarizes originated and acquired (subsequent to acquisition) impaired loans as of December 31, 2019 and 2018 (in thousands): At December 31, 2019 December 31, 2018 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 5,582 6,468 — 5,931 6,817 — Substandard 10,438 11,002 — 12,160 15,028 — One-to-four family residential LTV < 60% Pass 1,379 1,463 — 1,532 1,606 — Special Mention 385 385 — — — — Substandard 564 564 — 241 241 — LTV => 60% Pass 122 154 — 129 158 — Substandard 29 29 — 126 278 — Multifamily LTV < 35% Substandard 40 40 — 152 152 — LTV => 35% Pass 26 496 — 38 509 — Substandard 972 972 — 1,229 1,229 — Home Equity Pass 22 22 — 28 28 — Commercial and industrial loans Substandard 39 39 — 52 119 — With a Related Allowance Recorded: Real estate loans: Commercial LTV => 35% Substandard 1,307 1,307 (135 ) — — — One-to-four family residential LTV < 60% Substandard — — — 657 657 (18 ) LTV => 60% Pass — — — — — — Home equity and lines of credit Substandard 33 33 (3 ) 33 33 (5 ) Commercial and industrial loans Special Mention 19 19 (4 ) 21 21 (3 ) Total: Real estate loans: Commercial 17,327 18,916 (135 ) 18,091 21,984 — One-to-four family residential 2,479 2,595 — 2,685 2,940 (18 ) Multifamily 1,038 1,508 — 1,419 1,890 — Home equity and lines of credit 55 55 (3 ) 61 61 (5 ) Commercial and industrial loans 58 $ 58 (4 ) 73 140 (3 ) $ 20,957 $ 23,132 $ (142 ) $ 22,329 $ 27,015 $ (26 ) Included in the table above at December 31, 2019 , are impaired loans with carrying balances of $15.9 million that were not written down by charge-offs or for which there are no specific reserves in our allowance for loan losses. Included in the impaired loans at December 31, 2018 , are loans with carrying balances of $16.6 million that were not written down by charge-offs or for which there are no specific reserves in our allowance for loan losses. Loans not written down by charge-offs or specific reserves at December 31, 2019 and 2018 , have sufficient collateral values, less estimated costs to sell (including any discounts to facilitate a sale), or sufficient future cash flows to support the carrying balances of the loans. The following table summarizes the average recorded investment

Premises and Equipment, Net

Premises and Equipment, Net	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Premises and Equipment, Net	Premises and Equipment, Net At December 31, 2019 and 2018 , premises and equipment, less accumulated depreciation and amortization, consists of the following (in thousands): December 31, 2019 2018 At cost: Land $ 4,018 $ 4,018 Buildings and improvements 10,660 8,905 Capital leases 2,600 2,600 Furniture, fixtures, and equipment 26,179 24,140 Leasehold improvements 27,886 30,115 71,343 69,778 Accumulated depreciation and amortization (45,684 ) (44,173 ) Premises and equipment, net $ 25,659 $ 25,605 Depreciation expense for the years ended December 31, 2019 , 2018 , and 2017 , was $3.6 million , $3.0 million , and $3.2 million , respectively. Included in the depreciation expense for the year ended December 31, 2019 , is $470,000 of impairment charges on leasehold assets related to the consolidation of three branches on December 31, 2019 . There were no sales of premises and equipment in 2019 , 2018 , or 2017

Deposits

Deposits	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Deposits	Deposits Deposit account balances are summarized as follows (dollars in thousands): As of December 31, 2019 2018 Amount Weighted Average Rate Amount Weighted Average Rate Transaction: Negotiable orders of withdrawal and interest-bearing checking $ 573,927 0.87 % $ 458,012 0.68 % Non-interest bearing checking 387,409 — % 395,375 — % Total transaction 961,336 0.52 % 853,387 0.36 % Savings: Money market 651,159 1.18 % 741,939 1.12 % Savings 747,186 1.02 % 594,290 0.90 % Total savings 1,398,345 1.09 % 1,336,229 1.02 % Certificates of deposit: Under $100,000 563,303 1.86 % 599,245 1.91 % $100,000 or more 485,249 1.98 % 497,651 2.01 % Total certificates of deposit 1,048,552 1.92 % 1,096,896 1.96 % Total deposits $ 3,408,233 1.18 % $ 3,286,512 1.16 % The Company had brokered deposits (included in certificates of deposit in the above table) of $259.0 million and $275.4 million at December 31, 2019 and 2018 , respectively. Scheduled maturities of certificates of deposit are summarized as follows (in thousands): December 31, 2019 2020 $ 908,744 2021 46,856 2022 49,075 2023 35,008 2024 8,869 Total $ 1,048,552 Interest expense on deposits is summarized as follows (in thousands): Years Ended December 31, 2019 2018 2017 Transaction $ 4,623 $ 2,175 $ 1,429 Savings 15,850 8,878 6,804 Certificates of deposit 20,855 16,688 8,153 $ 41,328 $ 27,741 $ 16,386

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Borrowings	Borrowings Borrowings consisted of FHLB advances, securities sold under agreements to repurchase (repurchase agreements), and floating rate advances and are summarized as follows (in thousands): December 31, 2019 2018 Repurchase agreements $ 75,000 $ — Other borrowings: FHLB advances 776,000 403,502 Floating rate advances 6,004 5,345 Obligations under capital leases — 44 $ 857,004 $ 408,891 FHLB advances are secured by a blanket lien on unencumbered securities and the Company’s FHLB capital stock. FHLB advances and repurchase agreements have contractual maturities as follows (in thousands): December 31, 2019 FHLB Repurchase Advances Agreements 2020 $ 411,000 $ — 2021 145,000 25,000 2022 95,000 25,000 2023 87,500 — 2024 25,000 25,000 Thereafter 12,500 — $ 776,000 $ 75,000 Further information regarding FHLB advances and repurchase agreements is summarized as follows (in thousands): December 31, 2019 2018 2019 2018 FHLB Advances Repurchase Agreements Average balance during year $ 518,372 $ 448,012 $ 45,342 $ — Maximum outstanding at any month end $ 776,000 $ 475,582 $ 75,000 $ — Weighted average interest rate at end of year 2.04 % 1.95 % 2.30 % — % Weighted average interest rate during year 2.08 % 1.82 % 2.35 % — % All of the repurchase agreements mature after more than 90 days. The repurchase agreements are secured primarily by mortgage-backed securities with an amortized cost of $78.9 million and a fair value of $78.3 million . There were no repurchase agreements at December 31, 2018 . The Company has the ability to obtain additional funding from the FHLB and Federal Reserve Bank discount window of approximately $1.43 billion , utilizing unencumbered and unpledged securities of $284.8 million and multifamily loans of $1.1 billion at December 31, 2019 . 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): Years Ended December 31, 2019 2018 2017 Repurchase agreements $ 1,065 $ 7 $ 137 FHLB advances 10,795 8,172 7,390 Floating rate advances 170 123 33 Obligations under capital leases — 7 30 $ 12,030 $ 8,309 $ 7,590

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense (benefit) consists of the following (in thousands): Years Ended December 31, 2019 2018 2017 Federal tax expense (benefit): Current $ 8,543 $ 8,540 $ 10,113 Deferred 376 (742 ) 14,290 8,919 7,798 24,403 State and local tax expense (benefit): Current 4,067 1,985 1,672 Deferred (199 ) (151 ) 903 3,868 1,834 2,575 Total income tax expense $ 12,787 $ 9,632 $ 26,978 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, 2019 , 2018 , and 2017 , is as follows (dollars in thousands): Years Ended December 31, 2019 2018 2017 Tax expense at statutory rate $ 11,135 $ 10,439 $ 18,111 Applicable statutory federal income tax rate 21 % 21 % 35 % Increase (decrease) in taxes resulting from: State tax, net of federal income tax 3,056 1,448 1,674 Impact of 2017 federal tax reform — — 10,453 Bank owned life insurance (1,475 ) (778 ) (1,885 ) ESOP fair market value adjustment 187 196 404 Incentive stock options 81 146 247 Uncertain tax position — — 132 Excess tax benefits from employee share based payments (110 ) (1,939 ) (2,309 ) Other, net (87 ) 120 151 Income tax expense $ 12,787 $ 9,632 $ 26,978 Federal Tax Reform On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Act”) was signed into law. Among numerous provisions included in the Act was the reduction of the U.S. federal corporate income 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 fourth quarter of 2017, 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 . New Jersey State Taxation On July 1, 2018, the State Of New Jersey enacted new legislation which established a 2.5% surtax on businesses that have New Jersey allocated net income in excess of $1.0 million. The surtax was effective as of January 1, 2018 and will continue through 2019, and will adjust to 1.5% for 2020 and 2021. In addition, effective for taxable years beginning on or after January 1, 2019, banks will be required to file combined reports of taxable income including their parent holding company. In May 2019, the State of New Jersey issued a tax technical bulletin, subsequently revised in December 2019, which gives guidance on the treatment of real estate investment trusts in connection with the combined reporting for New Jersey corporate business tax purposes. Real estate investment trusts and investment companies will be excluded from the combined group and will continue to file separate New Jersey tax returns. As a result of this guidance the Company recorded an additional $889,000 of state tax expense net of federal benefit for the year ended December 31, 2019 . The $889,000 increase was comprised of $1.1 million of current tax expense, partially offset by a write-up of deferred tax assets of $239,000 . The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2019 and 2018 , are as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Allowance for loan losses $ 7,985 $ 7,317 Capitalized leases — 13 Deferred compensation 3,498 3,426 Accrued salaries 738 737 Postretirement benefits 376 375 Equity awards 2,164 3,045 Unrealized actuarial losses on post-retirement benefits (21 ) 18 Straight-line rent 1,277 1,051 Asset retirement obligation 70 67 Reserve for accrued interest receivable 578 602 Reserve for loan commitments 216 146 Employee Stock Ownership Plan 615 551 Other 244 261 Depreciation 2,414 2,383 Fair value adjustments of acquired loans 3,713 3,934 Fair value adjustments of pension benefit obligations 160 154 Unrealized losses on debt securities available-for-sale — 3,575 Total gross deferred tax assets 24,027 27,655 Deferred tax liabilities: Unrealized gains on debt securities available for sale 1,786 — Fair value adjustments of acquired securities 20 28 Fair value adjustments of deposit liabilities 219 285 Deferred loan fees 2,224 1,984 Other 30 33 Total gross deferred tax liabilities 4,279 2,330 Net deferred tax asset $ 19,748 $ 25,325 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 since it is “more likely than not” that the net deferred tax asset 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 asset 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, 2019 and December 31, 2018 , 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, 2019 2018 2017 Beginning balance $ 530 $ 482 $ 459 Settlements based on tax positions related to prior years (530 ) (238 ) (109 ) Additions based on tax positions related to prior years 190 286 132 Ending balance $ 190 $ 530 $ 482 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 2017 through present. • New York State tax filings 2015 through present. The 2015 through 2018 filings are currently under examination. • New York City tax filings 2015 through present. The 2015 filing is currently under examination. • State of New Jersey 2015 through present.

Retirement Benefits

Retirement Benefits	12 Months Ended
	Dec. 31, 2019
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 $426,000 , $394,000 , and $387,000 for the years ended December 31, 2019 , 2018 , and 2017 , respectively. 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, as adjusted. This purchase was funded with a loan from Northfield Bancorp, Inc. to the ESOP. The outstanding balance at December 31, 2019 and 2018 was $10.1 million and $10.8 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 100,841 and 101,514 shares were released and allocated to participants of the ESOP for the years ended December 31, 2019 and 2018 , 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, 2019 and 2018 was $11.8 million and $12.2 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 53,320 and 52,523 shares were released and allocated to participants of the second ESOP for the years ended December 31, 2019 and 2018 , 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, 2019 , 2018 , and 2017 was $1.9 million , $2.0 million , and $2.2 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 ESOP due to legal limitations imposed on tax-qualified plans. The Company's required contributions to the SESOP plan were $41,000 , $76,000 , and $84,000 for the years ended December 31, 2019 , 2018 , and 2017 , 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): 2019 2018 2017 Accumulated postretirement benefit obligation beginning of year $ 1,359 $ 1,645 $ 1,697 Service cost 9 11 11 Interest cost 52 52 57 Actuarial (gain) loss (76 ) (229 ) (8 ) Benefits paid (103 ) (120 ) (112 ) Accumulated postretirement benefit obligation end of year 1,241 1,359 1,645 Accrued liability (included in accrued expenses and other liabilities) $ 1,241 $ 1,359 $ 1,645 The following table sets forth the amounts recognized in accumulated other comprehensive income (loss) (in thousands): December 31, 2019 2018 Net loss $ 132 $ 20 Prior service credit (191 ) — (Gain) loss recognized in accumulated other comprehensive income (loss) $ (59 ) $ 20 The estimated net loss, prior service credit, and transition obligation that will be amortized from accumulated other comprehensive income into net periodic cost in 2019, are $835 , $19,000 , and $0 , respectively. The following table sets forth the components of net periodic postretirement benefit costs for the years ended December 31, 2019 , 2018 , and 2017 (in thousands): December 31, 2019 2018 2017 Service cost $ 9 $ 11 $ 11 Interest cost 52 52 57 Amortization of unrecognized loss 2 25 28 Net postretirement benefit cost included in compensation and employee benefits $ 63 $ 88 $ 96 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: 2019 2018 2017 Assumptions used to determine benefit obligation at period end: Discount rate 2.75 % 4.00 % 3.25 % Rate of increase in compensation 4.00 % 4.00 % 4.00 % Assumptions used to determine net periodic benefit cost for the year: Discount rate 4.00 % 3.25 % 3.50 % Rate of increase in compensation 4.00 % 4.00 % 4.00 % At December 31, 2019 , 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 2019 2018 2019 2018 Effect on benefits earned and interest cost $ 4 $ 4 $ (4 ) $ (3 ) Effect on accumulated postretirement benefit obligation $ 104 $ 109 $ (90 ) $ (94 ) 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 2019 2018 2017 2019 2018 2017 Aggregate of service and interest components of net periodic cost (benefit) $ 4 $ 4 $ 4 $ (4 ) $ (3 ) $ (4 ) Benefit payments of approximately $103,000 , $120,000 , and $112,000 were made in 2019 , 2018 , and 2017 , respectively. The benefits expected to be paid under the postretirement health benefits plan for the next five years are as follows: $108,000 in 2020 ; $108,000 in 2021 ; $107,000 in 2022 ; $88,000 in 2023 ; and $85,000 in 2024 . The benefit payments expected to be paid in the aggregate for the years 2025 through 2029 are $359,000 . The expected benefits are based on the same assumptions used to measure the Company’s benefit obligation at December 31, 2019 , 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 $14.7 million and $12.7 million at December 31, 2019 and 2018 , respectively, and is included in accrued expenses and other liabilities on the consolidated balance sheets. (Loss) income under this plan was $2.0 million , $(879,000) , and $1.1 million for the years ended December 31, 2019 , 2018 , and 2017 , 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, 2019
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 allowed the Company to grant common stock or options to purchase common stock at specific prices to directors and employees of the Company through December 31, 2018 . The 2008 EIP provided 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, 2018, no restricted shares or stock options remained available for issuance under the 2008 EIP. The ability of the Company to make grants under this plan, expired on December 17, 2018. On August 27, 2018 , the Company granted to an employee 3,378 restricted shares. These shares vested on February 27, 2019 . 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. 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 . There were no stock options granted in 2019 or 2018 . The fair value of stock options granted in 2017 was estimated utilizing the Black-Scholes option pricing model using the following assumptions: Year Ended December 31, 2017 Grant Date November 1, 2017 September 19, 2017 August 1, 2017 Stock options granted 40,000 12,500 45,744 Risk-free rate of return 2.06 % 1.89 % 1.86 % Volatility 29.22 % 30.06 % 29.46 % Dividend yield 2.37 % 1.98 % 1.91 % Expected life 5.75 5.75 5.75 Prior to May 22, 2019, the Company also maintained the Northfield Bancorp, Inc. 2014 Equity Incentive Plan (the “2014 EIP”) which allowed 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 provided 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, 2018, 142,154 restricted shares and 348,373 stock options were available for grant under the 2014 EIP. On August 27, 2018, the Company granted to an employee 11,622 restricted shares. These shares vest in three installments over a two year period beginning six months from the date of grant. All stock options and restricted stock granted prior to 2018 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 . On May 22, 2019, the Company's 2019 Equity Incentive Plan (the “2019 EIP”) was approved by stockholders of the Company. Under the 2019 EIP, the maximum number of shares of stock that may be delivered to participants in the form of stock options and stock appreciation rights (“SARs”) is 6,000,000 . To the extent an equity award is issued in the form of a restricted stock grant, or restricted stock unit, the number of stock options/SARs that can be granted is reduced by 4.5 . The maximum number of shares of stock that may be delivered to participants in the form of restricted stock awards and restricted stock units is 1,333,333 shares. As of December 31, 2019, no shares of stock have been granted under the 2019 EIP. Upon approval of the 2019 EIP, the 2014 EIP was frozen and equity awards that would otherwise have been available for issuance are no longer available for grant. As of December 31, 2018, the 142,154 restricted shares and 348,373 stock options which were available for grant are no longer available. During the years ended December 31, 2019 , 2018 , and 2017 , the Company recorded $3.2 million , $5.4 million , and $6.2 million of stock-based compensation, respectively. The following table is a summary of the Company’s non-vested stock options as of December 31, 2019 , 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, 2017 4,620,687 $ 3.51 $ 11.82 5.17 Forfeited (29,378 ) 3.36 11.51 — Exercised (1,339,714 ) 2.49 7.75 — Outstanding- December 31, 2018 3,251,595 3.93 13.51 5.62 Forfeited (15,000 ) 4.07 14.76 — Exercised (1,009,402 ) 3.75 12.54 — Outstanding - December 31, 2019 2,227,193 4.01 13.93 4.96 Exercisable - December 31, 2019 2,046,272 $ 3.99 $ 13.83 4.91 Expected future stock option expense related to the non-vested options outstanding as of December 31, 2019 , is $255,000 over an average period of 0.77 years. The following is a summary of the status of the Company’s restricted shares as of December 31, 2019 , and changes therein during the year then ended: Number of Shares Awarded Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 585,895 $ 14.05 Granted 15,000 16.48 Vested (266,973 ) 13.86 Forfeited (4,960 ) 14.18 Non-vested at December 31, 2018 328,962 14.31 Vested (249,860 ) 13.99 Forfeited (8,000 ) 14.76 Non-vested at December 31, 2019 71,102 $ 15.36 Expected future stock award expense related to the non-vested restricted awards as of December 31, 2019 , is $474,000 over an average period of 0.79 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, 2019
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, 2019 and 2018 , the following commitment and contingent liabilities existed that are not reflected in the accompanying consolidated financial statements (in thousands): December 31, 2019 2018 Commitments to extend credit $ 125,630 $ 39,326 Unused lines of credit 143,164 136,586 Standby letters of credit 6,713 5,352 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 both December 31, 2019 and 2018 . The Company maintains an allowance for estimated losses on commitments to extend credit in other liabilities. At December 31, 2019 and 2018 , the allowance was $756,000 and $523,000 , respectively, and changes to the allowance are recorded as a component of other non-interest expense. At December 31, 2019 , the Company was obligated under non-cancelable operating 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. For further details on leases see Note 18 - "Leases". 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, 2019
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. 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. Under the U.S. Basel III capital framework, both Northfield Bank and the Company must maintain minimum capital requirements which include: (i) a common equity Tier 1 capital to risk-based assets ratio of 4.5% ; (ii) a Tier 1 capital to risk-based assets ratio of 6% ; (iii) a total capital to risk-based assets of 8% ; and (iv) a Tier 1 capital to total assets leverage ratio of 4% . In addition to establishing the minimum regulatory capital requirements, the regulations limit capital distributions and certain discretionary bonus payments to management if the institution 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 increased each year until it was fully implemented at 2.5% on January 1, 2019. Management believes that as of December 31, 2019 and December 31, 2018 , the Bank exceeded all capital adequacy requirements to which it was subject at these dates. 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, 2019 and 2018 , 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, 2019: Common Equity Tier 1 Capital (to risk-weighted assets) $ 598,462 14.99 % $ 179,626 4.50 % $ 259,459 6.50 % Tier 1 Leverage 598,462 12.28 194,954 4.00 243,692 5.00 Tier I capital (to risk-weighted assets) 598,462 14.99 239,501 6.00 319,334 8.00 Total capital (to risk-weighted assets) 627,955 15.73 319,334 8.00 399,168 10.00 As of December 31, 2018: Common Equity Tier 1 Capital (to risk-weighted assets) $ 592,815 16.00 % $ 166,742 4.50 % $ 240,850 6.50 % Tier 1 Leverage 592,815 13.81 171,663 4.00 214,579 5.00 Tier I capital (to risk-weighted assets) 592,815 16.00 222,323 6.00 296,430 8.00 Total capital (to risk-weighted assets) 620,863 16.76 296,430 8.00 370,538 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, 2019 and 2018 , for classification as well-capitalized 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, 2019: Common Equity Tier 1 Capital (to risk-weighted assets) $ 651,974 16.35 % $ 179,439 4.50 % $ 259,189 6.50 % Tier 1 Leverage 651,974 13.37 195,018 4.00 243,772 5.00 Tier I capital (to risk-weighted assets) 651,974 16.35 239,251 6.00 319,002 8.00 Total capital (to risk-weighted assets) 681,467 17.09 319,002 8.00 398,752 10.00 As of December 31, 2018: Common Equity Tier 1 Capital (to risk-weighted assets) $ 636,141 17.17 % $ 166,717 4.50 % $ 240,814 6.50 % Tier 1 Leverage 636,141 14.82 171,724 4.00 214,656 5.00 Tier I capital (to risk-weighted assets) 636,141 17.17 222,290 6.00 296,386 8.00 Total capital (to risk-weighted assets) 664,190 17.93 296,386 8.00 370,483 10.00

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement The following table presents the assets reported on the consolidated balance sheets at their estimated fair value as of December 31, 2019 and 2018 , 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, 2019 and 2018 , 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, 2019 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: Debt securities available-for-sale: Mortgage-backed securities: Pass-through certificates: GSE $ 329,407 $ — $ 329,407 $ — REMICs: GSE 643,667 — 643,667 — Non-GSE 53 — 53 — 973,127 — 973,127 — Other debt securities: Municipal bonds 299 — 299 Corporate bonds 164,926 — 164,926 — 165,225 — 165,225 — Total debt securities available-for-sale 1,138,352 — 1,138,352 — Trading securities 11,222 11,222 — — Equity securities 250 250 — — Total 1,149,824 11,472 1,138,352 — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 4,871 $ — $ — $ 4,871 Multifamily 26 — — 26 Home equity and lines of credit 30 — — 30 Total impaired real estate loans 4,927 — — 4,927 Commercial and industrial loans 15 — — 15 Total $ 4,942 $ — $ — $ 4,942 Fair Value Measurements at December 31, 2018 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: Debt securities available-for-sale: Mortgage-backed securities: Pass-through certificates: GSE $ 314,788 $ — $ 314,788 $ — REMICs: GSE 250,163 — 250,163 — Non-GSE 58 — 58 — 565,009 — 565,009 — Other debt securities: Municipal Bonds 273 — 273 — Corporate bonds 242,749 — 242,749 — 243,022 — 243,022 — Total debt securities available-for sale 808,031 — 808,031 — Trading securities 8,968 8,968 — — Equity securities - mutual funds 237 237 — — Total $ 817,236 $ 9,205 $ 808,031 $ — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 4,847 $ — $ — $ 4,847 One-to-four family residential mortgage 765 — — 765 Multifamily 39 — — 39 Home equity and lines of credit 28 — — 28 Total impaired real estate loans 5,679 — — 5,679 Commercial and industrial loans 18 — — 18 Total $ 5,697 $ — $ — $ 5,697 The following table presents qualitative information for Level 3 assets measured at fair value on a non-recurring basis at December 31, 2019 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 4,942 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 4.13% - 6.25% The following table presents qualitative information for Level 3 assets measured at fair value on a non-recurring basis at December 31, 2018 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 5,697 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 4.13% - 6.25% Debt Securities Available-for-Sale: The estimated fair values for mortgage-backed securities, corporate and other debt 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. There were no transfers of securities between Level 1 and Level 2 during the years ended December 31, 2019 and 2018 . Trading Securities: Fair values are derived from quoted market prices in active markets. The assets consist of publicly traded mutual funds. Equity Securities: Fair values of equity securities consisting of publicly traded mutual funds are derived from quoted market prices in active markets. Impaired Loans: At December 31, 2019 , and December 31, 2018 , the Company had impaired loans held-for-investment with outstanding principal balances of $7.0 million and $10.2 million that were recorded at their estimated fair value of $4.9 million and $5.7 million , respectively. The Company recorded a net increase in the specific reserve for impaired loans of $116,000 for the year ended December 31, 2019 , as compared to a net decrease in the specific reserve for impaired loans of $56,000 for the year ended December 31, 2018. The Company recorded net recoveries of $1.2 million for the year ended December 31, 2019 , as compared to net charge-offs of $1.3 million for the year ended December 31, 2018, 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. 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) Debt 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) Investments in Equity Securities at Net Asset Value Per Share The Company uses net asset value as a practical expedient to record its investment in a private SBA Loan Fund since the shares in the fund are not publicly traded, do not have a readily determinable fair value and the net asset value per share is calculated in a manner consistent with the measurement principles of an investment company. (d) 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. (e) 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. (f) Loans (Held-for-Sale) Held-for-sale loans are carried at the lower of aggregate cost or estimated fair value, less estimated costs to sell, and therefore fair value is equal to carrying value. (g) Deposits The fair value of deposits with no stated maturity, such as interest and 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. (h) 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. (i) 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. (j) 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, 2019 and 2018 , are presented in the following table (in thousands): December 31, 2019 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 147,818 $ 147,818 $ — $ — $ 147,818 Trading securities 11,222 11,222 — — 11,222 Debt securities available-for-sale 1,138,352 — 1,138,352 — 1,138,352 Debt securities held-to-maturity 8,762 — 8,886 — 8,886 Equity securities (1) 250 250 — — 250 FHLB of New York stock, at cost 39,575 — 39,575 — 39,575 Net loans held-for-investment 3,408,378 — — 3,482,804 3,482,804 Financial liabilities: Deposits $ 3,408,233 $ — $ 3,412,414 $ — $ 3,412,414 Repurchase agreements, FHLB advances and other borrowings 857,004 — 862,980 — 862,980 Advance payments by borrowers 44,069 — 44,069 — 44,069 December 31, 2018 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 77,762 $ 77,762 $ — $ — $ 77,762 Trading securities 8,968 8,968 — — 8,968 Debt securities available-for-sale 808,031 — 808,031 — 808,031 Debt securities held-to-maturity 9,505 — 9,249 — 9,249 Equity securities (1) 237 237 — — 237 FHLB of New York stock, at cost 22,517 — 22,517 — 22,517 Net loans held-for-investment 3,217,673 — — 3,236,136 3,236,136 Financial liabilities: Deposits $ 3,286,512 $ — $ 3,291,085 $ — $ 3,291,085 Repurchase agreements, FHLB advances and other borrowings 408,891 — 403,476 — 403,476 Advance payments by borrowers 18,007 — 18,007 — 18,007 (1) Excludes $3.1 million and $1.0 million of investments measured at net asset value at December 31, 2019 and 2018, respectively, which have not been classified in the fair value hierarchy. 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, 2019
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 (dollars in thousands, except share and per share data): December 31, 2019 2018 2017 Net income available to common stockholders $ 40,235 $ 40,079 $ 24,768 Weighted average shares outstanding-basic 46,783,442 46,319,760 45,325,445 Effect of non-vested restricted stock and stock options outstanding 380,362 787,673 1,550,285 Weighted average shares outstanding-diluted 47,163,804 47,107,433 46,875,730 Earnings per share-basic $ 0.86 $ 0.87 $ 0.55 Earnings per share-diluted $ 0.85 $ 0.85 $ 0.53 Anti-dilutive shares 546,120 765,792 334,927

Stock Repurchase Program

Stock Repurchase Program	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stock Repurchase Program	Stock Repurchase Program On April 24, 2019 , the Company's Board of Directors approved a $37.2 million

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers The Company records revenue from contracts with customers in accordance with ASU 2014-09 (Topic 606), Revenue from Contracts with Customers . The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities, which comprise the majority of the Company’s revenue. The Company’s revenue streams that are within the scope of Topic 606 include service charges on deposit accounts, ATM and card interchange fees, investment services fees, and other miscellaneous income. Fees and service charges for customer services include: (i) service charges on deposit accounts, including account maintenance fees, overdraft fees, insufficient funds fees, wire fees, and other deposit related fees; (ii) ATM and card interchange fees, which include fees generated when a Bank cardholder uses a non-Bank ATM or a non-Bank cardholder uses a Bank ATM, and fees earned whenever the Bank's debit cards are processed through card payment networks such as Visa; and (iii) investment services fees earned through partnering with a third party investment and brokerage service firm to provide insurance and investment products to customers. The Company's performance obligation for fees and service charges is satisfied and related revenue recognized immediately or in the month of performance of services. Other income includes rental income from subleasing one of the Company's branches to a third party and income and gains or losses, net, related to OREO. For these transactions, revenue is recognized at the time the transaction occurs. The following table summarizes non-interest income for the years indicated (dollars in thousands): December 31, 2019 2018 2017 Fees and service charges for customer services: Service charges $ 3,309 $ 3,356 $ 3,320 ATM and card interchange fees 1,310 1,216 1,150 Investment fees 262 305 232 Total fees and service charges for customer services 4,881 4,877 4,702 Income on bank owned life insurance (1) 7,023 3,705 5,386 Gains (losses) on available-for-sale debt securities, net (1) 1,988 (879 ) 1,114 Gains on trading securities, net (1) 514 178 169 Other (1) 402 246 271 Total non-interest income $ 14,808 $ 8,127 $ 11,642 (1) Not within the scope of Topic 606

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases Effective January 1, 2019, the Company adopted ASU 2016-02, Leases ( “ Topic 842 ” ) and all subsequent ASU's that modified Topic 842. The Company’s leases primarily relate to real estate property for branches and office space with terms extending from nine months up to 35.5 years . At December 31, 2019 , all of the Company's leases are classified as operating leases. The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use assets and operating lease liabilities in the consolidated balance sheets. Right-of-use assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recorded at the present value of lease payments over the lease term. As the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate in determining the present value of lease payments. Certain leases include options to renew, with one or more renewal terms ranging from five to 10 years . As these extension options are not generally considered reasonably certain of renewal, they are not included in the lease term. At December 31, 2019 , the Company’s operating lease right-of-use assets and related lease liabilities included in the consolidated balance sheet were $39.5 million and $44.1 million , respectively. Operating lease expense is recognized on a straight-line basis over the lease term, while variable lease payments are recognized as incurred. Variable lease payments include common area maintenance charges, real estate taxes, repairs and maintenance costs and utilities. Operating and variable lease expenses are recorded in occupancy expense in the consolidated statements of income. Supplemental lease information at or for the year ended December 31, 2019 is as follows (dollars in thousands): Operating lease cost $ 6,698 Variable lease cost 2,813 Net lease cost $ 9,511 Cash paid for amounts included in measurement of operating lease liabilities $ 5,901 Right-of-use assets obtained in exchange for new operating lease liabilities $ 1,013 Weighted average remaining lease term (in years) at December 31, 2019 12.77 Weighted average discount rate at December 31, 2019 3.62 % The following table summarizes lease payment obligations for each of the next five years and thereafter in addition to a reconcilement to the Company's current lease liability (dollars in thousands): Year Amount 2020 $ 6,160 2021 5,730 2022 5,068 2023 4,975 2024 4,629 Thereafter 30,668 Total lease payments $ 57,230 Less: imputed interest (13,161 ) Present value of lease liabilities $ 44,069 Net rental expense included in occupancy expense was approximately $6.8 million , $5.7 million , and $5.3 million for the years ended December 31, 2019 , 2018 , and 2017 , respectively. Included in rental expense for the year ended December 31, 2019, is approximately $579,000 of accelerated rental expense related to the consolidation of three branches on December 31, 2019 . As of December 31, 2019 , the Company had not entered into any leases that have not yet commenced.

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives The Company’s derivative financial instruments are used to provide to certain qualified commercial borrowers in loan related transactions and, therefore, are not used to manage interest rate risk. The Company executes interest rate swaps with qualified commercial banking customers to facilitate their respective risk management strategies. Those interest rate swaps are simultaneously hedged by offsetting interest rate swaps that the Company executes with a third-party, such that the Company minimizes its net risk exposure resulting from such transactions. The interest rate swap agreement which the Company executes with the commercial borrower is collateralized by the borrower’s commercial real estate financed by the Company. The collateral exceeds the maximum potential amount of future payments under the credit derivative. As these interest rate swaps do not meet the hedge accounting requirements, changes in the fair value of both the customer swaps and the offsetting swaps are recognized directly in earnings. During the fourth quarter of 2019, the Company entered into its first derivative transaction. At December 31, 2019, the Company had one interest rate swap with a notional amount of $12.0 million , and the fair value of the asset and liability derivative was $79,000 . For the year ended December 31, 2019, the Company recorded fee income of approximately $147,000 . At December 31, 2018, the Company did no t have any derivative assets or liabilities and had not entered into any derivative transactions prior to then.

Parent-only Financial Informati

Parent-only Financial Information	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information 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, 2019 2018 (in thousands) Assets Cash in Northfield Bank $ 32,828 $ 21,884 Interest-earning deposits in other financial institutions 280 21 Investment in Northfield Bank 642,341 623,113 ESOP loan receivable 21,897 22,962 Other assets 132 120 Total assets $ 697,478 $ 668,100 Liabilities and Stockholders' Equity Total liabilities $ 1,625 $ 1,661 Total stockholders' equity 695,853 666,439 Total liabilities and stockholders' equity $ 697,478 $ 668,100 Northfield Bancorp, Inc. Condensed Statements of Comprehensive Income Years Ended December 31, 2019 2018 2017 (in thousands) Interest on ESOP loan $ 1,263 $ 1,081 $ 939 Interest income on deposits in other financial institutions 229 38 31 Gains (losses) gains on securities, net 10 (6 ) 5 Undistributed earnings of Northfield Bank 40,012 40,092 24,887 Total income 41,514 41,205 25,862 Other expenses 863 890 872 Income tax expense 416 236 222 Total expense 1,279 1,126 1,094 Net income $ 40,235 $ 40,079 $ 24,768 Comprehensive income: Net income $ 40,235 $ 40,079 $ 24,768 Other comprehensive income (loss), net of tax 13,846 (3,696 ) (227 ) Comprehensive income $ 54,081 $ 36,383 $ 24,541 Northfield Bancorp, Inc. Condensed Statements of Cash Flows Years Ended December 31, 2019 2018 2017 (in thousands) Cash flows from operating activities Net income $ 40,235 $ 40,079 $ 24,768 Adjustments to reconcile net income to net cash (used in) provided by operating activities: (Increase) decrease in other assets (1,073 ) 3 (2,008 ) (Gains) losses on securities, net (10 ) 6 (5 ) (Decrease) increase in other liabilities (36 ) 846 (980 ) Undistributed earnings of Northfield Bank (40,012 ) (40,092 ) (24,887 ) Net cash (used in) provided by operating activities (896 ) 842 (3,112 ) Cash flows from investing activities Dividends from Northfield Bank 41,277 16,493 28,763 Net cash provided by investing activities 41,277 16,493 28,763 Cash flows from financing activities Principal payments on ESOP loan receivable 1,065 1,059 1,022 Purchase of treasury stock (15,815 ) (5 ) — Dividends paid (20,198 ) (18,673 ) (15,646 ) Exercise of stock options 5,770 2,088 100 Net cash used in financing activities (29,178 ) (15,531 ) (14,524 ) Net increase in cash and cash equivalents 11,203 1,804 11,127 Cash and cash equivalents at beginning of year 21,905 20,101 8,974 Cash and cash equivalents at end of year $ 33,108 $ 21,905 $ 20,101

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 : 2019 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 39,466 $ 40,193 $ 42,847 $ 42,637 Interest expense 12,136 13,034 14,027 14,161 Net interest income 27,330 27,159 28,820 28,476 Provision (recoveries) for loan losses 59 491 (1,300 ) 772 Net interest income after provision for loan losses 27,271 26,668 30,120 27,704 Other income 3,314 2,566 4,733 4,195 Other expenses 19,204 18,750 16,869 18,726 Income before income tax expense 11,381 10,484 17,984 13,173 Income tax expense 2,610 2,280 4,845 3,052 Net income $ 8,771 $ 8,204 $ 13,139 $ 10,121 Net income per basic common share $ 0.19 $ 0.18 $ 0.28 $ 0.22 Net income per diluted common share $ 0.19 $ 0.17 $ 0.28 $ 0.21 2018 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 34,682 $ 35,935 $ 37,727 $ 38,948 Interest expense 7,138 8,165 9,803 10,944 Net interest income 27,544 27,770 27,924 28,004 Provision for loan losses 34 670 1,304 607 Net interest income after provision for loan losses 27,510 27,100 26,620 27,397 Other income 2,405 2,445 2,637 640 Other expenses 17,126 17,040 17,100 15,777 Income before income tax expense 12,789 12,505 12,157 12,260 Income tax expense 2,344 1,893 3,081 2,314 Net income $ 10,445 $ 10,612 $ 9,076 $ 9,946 Net income per basic common share $ 0.23 $ 0.23 $ 0.19 $ 0.21 Net income per diluted common share $ 0.22 $ 0.23 $ 0.19 $ 0.21

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
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 debt securities held-to-maturity, debt securities available-for-sale, trading account securities or equity securities. Debt securities held-to-maturity are those that management has the positive intent and ability to hold until maturity. Debt 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. Debt securities available-for-sale represents all securities not classified as either held-to-maturity, trading, or equity. Debt 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, using quoted prices in active markets, with unrealized holding gains and losses reported as a component of gain (loss) on securities, net in non-interest income. Equity securities with readily determinable fair values are stated at fair value with unrealized gains and losses reported as a component of gain (loss) on securities, net in non-interest income. Equity securities without readily determinable fair values are recorded at net asset value less any impairment, if any.
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 estimated costs 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 consecutive 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 estimated 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 at least 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, 2019 and 2018 .
Operating Leases	Operating Leases During the normal course of business, the Company enters into agreements, and at inception it determines if a particular agreement is a lease. The Company's operating lease agreements relate primarily to its corporate offices and bank branch offices. The agreements are recorded as operating lease right-of-use assets and operating lease liabilities on the consolidated balance sheets. Operating lease right of use assets and operating lease liabilities are recognized at the commencement date based on the present value of lease payments over the lease term, and represent the right to use an underlying asset for the lease term and the obligation to make lease payments arising from the lease. As the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate in determining the present value of lease payments. The Company's lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the term of the lease.
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, 2019 , 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, 2019 , the carrying value of goodwill totaled $38.4 million . The Company performed its annual goodwill impairment test, as of December 31, 2019 , 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 estimated 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 debt 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. 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 Company accounts for forfeitures as they occur. 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 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 was applied prospectively upon adoption. When applying the treasury stock method for the years ended December 31, 2018 and 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 year ended December 31, 2016, 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.
Advertising costs	Advertising costs
Recent Accounting Developments	(t) Derivatives During the fourth quarter of 2019, the Company began offering interest rate swaps to certain qualified commercial borrowers. These interest rate swaps result from a service provided to certain qualifying borrowers in a loan-related transaction and, therefore, are not used to manage interest rate risk in the Company’s assets or liabilities. As such, all changes in the fair value of these derivatives are recognized directly in earnings. The Company records all derivatives on the Consolidated Balance Sheets at fair value. (u) Recent Accounting Pronouncements Adopted ASU No. 2016-02. In February 2016, the FASB issued ASU No. 2016-02, Leases ( “ Topic 842 ” ) , which requires all lessees to recognize a lease liability and a right-of-use asset, measured at the present value of the future minimum lease payments, at the lease commencement date for leases classified as operating leases as well as finance leases. Under this guidance, lessor accounting is largely unchanged. This ASU became effective for annual and interim periods for the Company on January 1, 2019. The Company adopted the standard by applying the alternative transition method whereby comparative periods were not restated, and no cumulative effect adjustment to the opening balance of retained earnings was recognized as of January 1, 2019. The Company also elected the ASU’s package of three practical expedients, which allowed the Company to forego a reassessment of (i) whether any expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases and (iii) the initial direct costs for any existing leases. The Company also elected not to apply the recognition requirements of the ASU to any short-term leases (as defined by related accounting guidance) and will account for lease and non-lease components separately because such amounts are readily determinable under most lease contracts. The adoption of this standard resulted in the Company recognizing operating lease right-of-use assets and related operating lease liabilities totaling $43.6 million and $47.3 million respectively, as of January 1, 2019 . The adoption of this ASU did not have a material impact on the Company’s consolidated results of operations. See Note 18, Leases, for further disclosures. ASU No. 2017-08. In March 2017, the FASB issued ASU No. 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities . The amendments in this update require the premium on callable debt securities to be amortized to the earliest call date rather than the maturity date; however, securities held at a discount continue to be amortized to maturity. The amendments apply only to debt securities purchased at a premium that are callable at fixed prices and on preset dates. The amendments more closely align interest income recorded on debt securities held at a premium or discount with the economics of the underlying instrument. This ASU became effective for the Company on January 1, 2019, and did not have a material impact on the Company's consolidated financial statements. ASU No. 2018-07. In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, which is intended to align the accounting for share-based payment awards issued to employees and nonemployees. The guidance applies to nonemployee awards issued in exchange for goods or services used or consumed in an entity’s own operations and to awards granted by an investor to employees and nonemployees of an equity method investee for goods or services used or consumed in the investee’s operations. There are no new disclosure requirements. This ASU became effective for the Company on January 1, 2019. Adoption of this ASU did not have an impact on the Company's consolidated financial statements, as share-based payment awards to nonemployee Directors are accounted for in the same manner as share-based payment awards for employees. ASU No. 2014-09. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) . The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies generally will be required to use more judgment and make more estimates than under current guidance. These may include identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. Subsequent to the issuance of ASU No. 2014-09, the FASB issued targeted updates to clarify specific implementation issues including ASU No. 2016-08, “Principal versus Agent Considerations (Reporting Revenue Gross versus Net),” ASU No. 2016-10, “Identifying Performance Obligations and Licensing,” ASU No. 2016-12, “Narrow-Scope Improvements and Practical Expedients,” and ASU No. 2016-20 “Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers.” The new standard was effective for the Company on January 1, 2018. The adoption of ASU No. 2014-09 did not have a material impact on the Company’s consolidated financial statements and related disclosures as the Company’s primary sources of revenues are derived from interest income on financial assets that are not within the scope of the guidance. Management conducted an assessment of the revenue streams that were potentially affected by the guidance and reviewed contracts in scope to ensure compliance with the guidance. These contracts included those related to service charges on deposit accounts, ATM and card interchange fees, and investment services fees. The Company’s revenue recognition pattern for these revenue streams did not change from current practice. Additional disclosures required by the standard have been included in Note 17. “Revenue from Contracts with Customers.” ASU No. 2016-01. 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 including the following: 1) Requires equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income; 2) Simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; 3) Requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; 4) Requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value and 5) Reduces diversity in current practice by clarifying that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available for sale securities in combination with the entity’s other deferred tax assets. ASU No. 2016-01 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company adopted ASU No. 2016-01 effective January 1, 2018, which did not have a material impact on the Company’s consolidated financial statements due to the Company's proportionately small portfolio of equity securities and no liabilities that are measured at fair value. The primary impact of the adoption of ASU No. 2016-01 was the reclassification of equity securities from available-for-sale to equity securities on the consolidated balance sheets and the use of an exit price notion for valuing loans at fair value. See Note 4 - “Equity Securities” and Note 14 - “Fair Value Measurement” for further details. ASU No. 2016-15. 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 how certain cash receipts and cash payments should be classified and presented in the statement of cash flows. ASU No. 2016-15 includes guidance on eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. ASU No. 2016-15 is effective for annual and interim reporting periods beginning after December 15, 2017. The Company adopted ASU No. 2016-15 effective January 1, 2018, which did not have a material impact on the Company's consolidated statements of cash flows. ASU No. 2017-07. In March 2017, the FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost , which requires that companies disaggregate the service cost component from other components of net benefit cost. The guidance requires companies that offer postretirement benefits to present the service cost, which is the amount an employer has to set aside each quarter or fiscal year to cover the benefits, in the same line item with other current employee compensation costs. Other components of net benefit cost will be presented in the income statement separately from the service cost component and outside the subtotal of income from operations, if one is presented. The Company adopted ASU No. 2017-07 effective January 1, 2018, which did not have a material impact on the Company’s consolidated financial statements. ASU No. 2018-02. 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 guidance 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. ASU No. 2018-03. In February 2018, the FASB issued ASU No. 2018-03, Technical Corrections and Improvements to Financial Instruments-Overall (Subtopic 825-10), which clarifies certain aspects of the guidance issued in ASU No. 2016-01 including: the ability to irrevocably elect to change the measurement approach for equity securities measured using the practical expedient (at cost plus or minus observable transactions less impairment) to a fair value method in accordance with Topic 820, Fair Value Measurement; clarification that if an observable transaction occurs for such securities, the adjustment is as of the observable transaction date; clarification that the prospective transition approach for equity securities without a readily determinable fair value is meant only for instances in which the practical expedient is elected; and various other clarifications. ASU No. 2018-03 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years beginning after June 15, 2018. The Company adopted ASU No. 2018-03 during the third quarter 2018, which did not have a material impact on the Company’s consolidated financial statements.
Fair Value Measurement	Fair Value Measurement The following table presents the assets reported on the consolidated balance sheets at their estimated fair value as of December 31, 2019 and 2018 , 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) Debt 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) Investments in Equity Securities at Net Asset Value Per Share The Company uses net asset value as a practical expedient to record its investment in a private SBA Loan Fund since the shares in the fund are not publicly traded, do not have a readily determinable fair value and the net asset value per share is calculated in a manner consistent with the measurement principles of an investment company. (d) 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. (e) 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. (f) Loans (Held-for-Sale) Held-for-sale loans are carried at the lower of aggregate cost or estimated fair value, less estimated costs to sell, and therefore fair value is equal to carrying value. (g) Deposits The fair value of deposits with no stated maturity, such as interest and 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. (h) 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. (i) 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. (j) 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.

Debt Securities Available-for_2

Debt Securities Available-for-Sale (Tables)	12 Months Ended
	Dec. 31, 2019
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 and other debt securities available-for-sale at December 31, 2019 and 2018 (in thousands): 2019 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: Government sponsored enterprises (GSE) $ 324,080 $ 6,081 $ 754 $ 329,407 Real estate mortgage investment conduits (REMICs): GSE 643,816 2,076 2,225 643,667 Non-GSE 53 — — 53 967,949 8,157 2,979 973,127 Other debt securities: Municipal bonds 296 3 — 299 Corporate bonds 163,725 1,214 13 164,926 164,021 1,217 13 165,225 Total debt securities available-for-sale $ 1,131,970 $ 9,374 $ 2,992 $ 1,138,352 2018 Gross Gross Estimated Amortized unrealized unrealized fair cost gains losses value Mortgage-backed securities: Pass-through certificates: GSE $ 317,530 $ 800 $ 3,542 $ 314,788 REMICs: GSE 258,050 92 7,979 250,163 Non-GSE 59 — 1 58 575,639 892 11,522 565,009 Other debt securities: Municipal bonds 270 3 — 273 Corporate bonds 244,892 72 2,215 242,749 245,162 75 2,215 243,022 Total debt securities available-for-sale $ 820,801 $ 967 $ 13,737 $ 808,031
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, 2019 (in thousands): Available-for-sale Amortized cost Estimated fair value Due in one year or less $ 75,115 $ 75,353 Due after one year through five years 88,906 89,872 $ 164,021 $ 165,225
Gross Unrealized Losses on Mortgage-Backed Securities	Gross unrealized losses on mortgage-backed securities and other debt 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, 2019 and 2018 , were as follows (in thousands): December 31, 2019 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 $ 25 $ 3,404 $ 729 $ 55,184 $ 754 $ 58,588 REMICs: GSE 950 197,634 1,275 54,555 2,225 252,189 Non-GSE — — — 53 — 53 Other debt securities: Corporate bonds — — 13 15,586 13 15,586 Total $ 975 $ 201,038 $ 2,017 $ 125,378 $ 2,992 $ 326,416 December 31, 2018 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 $ 404 $ 82,781 $ 3,138 $ 100,109 $ 3,542 $ 182,890 REMICs: GSE 269 46,921 7,710 181,512 7,979 228,433 Non-GSE — — 1 58 1 58 Other debt securities: Corporate bonds 1,703 173,219 512 25,675 2,215 198,894 Total $ 2,376 $ 302,921 $ 11,361 $ 307,354 $ 13,737 $ 610,275

Debt Securities Held-to-Matur_2

Debt Securities Held-to-Maturity (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 (in thousands): 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 8,762 $ 129 $ 5 $ 8,886 Total securities held-to-maturity $ 8,762 $ 129 $ 5 $ 8,886 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Mortgage-backed securities: Pass-through certificates: GSEs $ 9,505 $ — $ 256 $ 9,249 Total securities held-to-maturity $ 9,505 $ — $ 256 $ 9,249
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, 2019 and 2018 , were as follows (in thousands): December 31, 2019 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 $ — $ — $ 5 $ 378 $ 5 $ 378 Total $ — $ — $ 5 $ 378 $ 5 $ 378 December 31, 2018 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 $ 34 $ 2,133 $ 222 $ 7,116 $ 256 $ 9,249 Total $ 34 $ 2,133 $ 222 $ 7,116 $ 256 $ 9,249

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Net Loans Held-For-Investment	Loans held-for-investment, net, consists of the following (in thousands): December 31, 2019 2018 Originated loans: Real estate loans: Multifamily $ 2,196,407 $ 1,930,535 Commercial mortgage 528,681 499,311 One-to-four family residential mortgage 83,742 91,371 Home equity and lines of credit 84,928 78,593 Construction and land 38,284 26,552 Total real estate loans 2,932,042 2,626,362 Commercial and industrial loans 45,328 44,104 Other loans 2,083 1,519 Total commercial and industrial and other loans 47,411 45,623 Deferred loan cost, net 7,614 6,892 Originated loans held-for-investment, net 2,987,067 2,678,877 PCI Loans 17,365 20,143 Loans acquired: One-to-four family residential mortgage 187,975 225,877 Multifamily 108,417 145,485 Commercial mortgage 113,027 133,263 Home equity and lines of credit 12,008 17,583 Construction and land 2,537 12,003 Total acquired real estate loans 423,964 534,211 Commercial and industrial loans 8,689 11,933 Other loans — 6 Total loans acquired 432,653 546,150 Loans held for investment, net 3,437,085 3,245,170 Allowance for loan losses (28,707 ) (27,497 ) Net loans held-for-investment $ 3,408,378 $ 3,217,673
Summary of Changes in Accretable Yields of Acquired Loans	The following details the accretable yield (in thousands): For The Year Ended December 31, 2019 2018 Balance at the beginning of year $ 21,846 $ 24,502 Accretion into interest income (4,142 ) (4,176 ) Net reclassification from non-accretable difference (1) (618 ) 1,520 Balance at end of year $ 17,086 $ 21,846 (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, 2019 , 2018 , and 2017 follows (in thousands): Year Ended December 31, 2019 2018 2017 Balance at beginning of year $ 27,497 $ 26,160 $ 24,595 Provision for loan losses 22 2,615 1,411 Recoveries 2,175 112 556 Charge-offs (987 ) (1,390 ) (402 ) Balance at end of year $ 28,707 $ 27,497 $ 26,160 The following table sets forth activity in our allowance for loan losses, by loan type, for the years ended December 31, 2019 and 2018 . 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): Year Ended December 31, 2019 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 5,630 $ 342 $ 463 $ 18,084 $ 291 $ 1,569 $ 108 $ 26,487 $ 1,010 $ — $ 27,497 Charge-offs (520 ) — — — — (100 ) (123 ) (743 ) — (244 ) (987 ) Recoveries 98 72 — 1,818 — 20 1 2,009 — 166 2,175 Provisions (credit) (452 ) (234 ) 73 301 26 151 165 30 (221 ) 213 22 Ending Balance $ 4,756 $ 180 $ 536 $ 20,203 $ 317 $ 1,640 $ 151 $ 27,783 $ 789 $ 135 $ 28,707 Ending balance: individually evaluated for impairment $ — $ — $ — $ — $ 3 $ 4 $ — $ 7 $ — $ 135 $ 142 Ending balance: collectively evaluated for impairment $ 4,756 $ 180 $ 536 $ 20,203 $ 314 $ 1,636 $ 151 $ 27,776 $ 789 $ — $ 28,565 Loans, net: Ending Balance $ 529,287 $ 85,355 $ 38,303 $ 2,199,734 $ 86,848 $ 45,456 $ 2,084 $ 2,987,067 $ 17,365 $ 432,653 $ 3,437,085 Ending balance: individually evaluated for impairment $ 13,226 $ 1,841 $ — $ 997 $ 55 $ 58 $ — $ 16,177 $ — $ 4,780 $ 20,957 Ending balance: collectively evaluated for impairment $ 516,061 $ 83,514 $ 38,303 $ 2,198,737 $ 86,793 $ 45,398 $ 2,084 $ 2,970,890 $ 17,365 $ 427,873 $ 3,416,128 Year Ended December 31, 2018 Real Estate Commercial One-to-Four Family Construction and Land Multifamily Home Equity and Lines of Credit Commercial and Industrial Other Originated Loans Total PCI Acquired Loans Total Allowance for loan losses: Beginning Balance $ 5,196 $ 503 $ 610 $ 17,374 $ 122 $ 1,273 $ 94 $ 25,172 $ 951 $ 37 $ 26,160 Charge-offs (1,256 ) (3 ) — — (60 ) (70 ) — (1,389 ) — (1 ) (1,390 ) Recoveries 49 4 — 26 — 20 — 99 — 13 112 Provisions (credit) 1,641 (162 ) (147 ) 684 229 346 14 2,605 59 (49 ) 2,615 Ending Balance $ 5,630 $ 342 $ 463 $ 18,084 $ 291 $ 1,569 $ 108 $ 26,487 $ 1,010 $ — $ 27,497 Ending balance: individually evaluated for impairment $ — $ 18 $ — $ — $ 5 $ 3 $ — $ 26 $ — $ — $ 26 Ending balance: collectively evaluated for impairment $ 5,630 $ 324 $ 463 $ 18,084 $ 286 $ 1,566 $ 108 $ 26,461 $ 1,010 $ — $ 27,471 Loans, net: Ending Balance $ 499,860 $ 92,433 $ 26,613 $ 1,933,946 $ 80,315 $ 44,190 $ 1,520 $ 2,678,877 $ 20,143 $ 546,150 $ 3,245,170 Ending balance: individually evaluated for impairment $ 15,252 $ 1,893 $ — $ 1,268 $ 61 $ 73 $ — $ 18,547 $ — $ 3,782 $ 22,329 Ending balance: collectively evaluated for impairment $ 484,608 $ 90,540 $ 26,613 $ 1,932,678 $ 80,254 $ 44,117 $ 1,520 $ 2,660,330 $ 20,143 $ 542,368 $ 3,222,841
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, 2019 and 2018 (in thousands): At December 31, 2019 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 $ 232,950 $ 1,960,984 $ 79,485 $ 440,065 $ 52,886 $ 29,967 $ 38,303 $ 86,547 $ 45,075 $ 2,084 $ 2,968,346 Special Mention — 296 370 1,092 777 — — 14 301 — 2,850 Substandard 301 5,203 — 8,275 1,397 328 — 287 80 — 15,871 Originated loans held-for-investment, net $ 233,251 $ 1,966,483 $ 79,855 $ 449,432 $ 55,060 $ 30,295 $ 38,303 $ 86,848 $ 45,456 $ 2,084 $ 2,987,067 At December 31, 2018 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 $ 170,832 $ 1,756,882 $ 78,917 $ 409,155 $ 54,912 $ 34,808 $ 26,613 $ 80,077 $ 43,640 $ 1,520 $ 2,657,356 Special Mention — 613 395 1,137 747 — — 27 430 — 3,349 Substandard — 5,619 — 10,256 1,406 560 — 211 120 — 18,172 Originated loans held-for-investment, net $ 170,832 $ 1,763,114 $ 79,312 $ 420,548 $ 57,065 $ 35,368 $ 26,613 $ 80,315 $ 44,190 $ 1,520 $ 2,678,877
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, 2019 and 2018 (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, 2019 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 $ — $ — $ 2,416 $ 2,416 $ — $ 2,416 Total commercial — — 2,416 2,416 — 2,416 One-to-four family residential LTV < 60% Substandard — — 493 493 114 607 Total — — 493 493 114 607 LTV => 60% Substandard — 29 — 29 — 29 Total one-to-four family residential — 29 493 522 114 636 Construction and land Home equity and lines of credit Substandard — 67 89 156 — 156 Total home equity and lines of credit — 67 89 156 — 156 Total non-performing loans held-for-investment, originated — 96 2,998 3,094 114 3,208 Loans acquired: Real Estate Loans: Commercial LTV < 35% Substandard 79 — 188 267 66 333 LTV => 35% Substandard 3,530 — 1,709 5,239 187 5,426 Total commercial 3,609 — 1,897 5,506 253 5,759 One-to-four family residential LTV < 60% Substandard 190 — 85 275 151 426 Total 190 — 85 275 151 426 LTV => 60% Substandard — — 93 93 — 93 Total one-to-four family residential 190 — 178 368 151 519 Multifamily LTV < 35% Substandard 40 — — 40 — 40 LTV => 35% Substandard — 397 — 397 — 397 Total multifamily 40 397 — 437 — 437 Home equity and lines of credit Substandard — — 28 28 — 28 Total home equity and lines of credit — — 28 28 — 28 Total non-performing loans acquired 3,839 397 2,103 6,339 404 6,743 Total non-performing loans $ 3,839 $ 493 $ 5,101 $ 9,433 $ 518 $ 9,951 At December 31, 2018 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 $ — $ 287 $ 2,588 $ 2,875 $ — $ 2,875 Total commercial — 287 2,588 2,875 — 2,875 One-to-four family residential LTV < 60% Substandard — 432 77 509 — 509 LTV => 60% Substandard — 32 — 32 — 32 Total one-to-four family residential — 464 77 541 — 541 Home equity and lines of credit Substandard 75 — — 75 — 75 Total home equity and lines of credit 75 — — 75 — 75 Commercial and industrial loans Substandard — — 25 25 — 25 Total commercial and industrial loans — — 25 25 — 25 Total non-performing loans held-for-investment, originated 75 751 2,690 3,516 — 3,516 Loans acquired: Real Estate Loans: Commercial LTV < 35% Substandard 87 — 194 281 — 281 LTV => 35% Substandard — 764 3,371 4,135 — 4,135 Total commercial 87 764 3,565 4,416 — 4,416 One-to-four family residential LTV < 60% Substandard — 199 169 368 6 374 LTV => 60% Substandard 126 — 93 219 27 246 Total one-to-four family residential 126 199 262 587 33 620 Multifamily LTV < 35% Substandard 152 — — 152 — 152 LTV => 35% Substandard — 414 — 414 — 414 Total multifamily 152 414 — 566 — 566 Home equity and lines of credit Substandard — — 77 77 — 77 Total home equity and lines of credit — — 77 77 — 77 Total non-performing loans acquired 365 1,377 3,904 5,646 33 5,679 Total non-performing loans $ 440 $ 2,128 $ 6,594 $ 9,162 $ 33 $ 9,195
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, 2019 and 2018 (in thousands): December 31, 2019 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 $ 79,383 $ 102 $ 79,485 $ — $ 79,485 Special Mention 370 — 370 — 370 Total 79,753 102 79,855 — 79,855 LTV => 35% Pass 439,253 812 440,065 — 440,065 Special Mention 1,092 — 1,092 — 1,092 Substandard 5,228 631 5,859 2,416 8,275 Total 445,573 1,443 447,016 2,416 449,432 Total commercial 525,326 1,545 526,871 2,416 529,287 One-to-four family residential LTV < 60% Pass 52,757 129 52,886 — 52,886 Special Mention — 777 777 — 777 Substandard 790 — 790 607 1,397 Total 53,547 906 54,453 607 55,060 LTV => 60% Pass 29,741 226 29,967 — 29,967 Substandard 299 — 299 29 328 Total 30,040 226 30,266 29 30,295 Total one-to-four family residential 83,587 1,132 84,719 636 85,355 Construction and land Pass 38,156 147 38,303 — 38,303 Total construction and land 38,156 147 38,303 — 38,303 Multifamily LTV < 35% Pass 232,658 292 232,950 — 232,950 Substandard 301 — 301 — 301 Total 232,959 292 233,251 — 233,251 LTV= > 35% Pass 1,960,729 255 1,960,984 — 1,960,984 Special Mention 296 — 296 — 296 Substandard 5,203 — 5,203 — 5,203 Total 1,966,228 255 1,966,483 — 1,966,483 Total multifamily 2,199,187 547 2,199,734 — 2,199,734 Home equity and lines of credit Pass 86,380 167 86,547 — 86,547 Special Mention 14 — 14 — 14 Substandard 131 — 131 156 287 Total home equity and lines of credit 86,525 167 86,692 156 86,848 Commercial and industrial loans Pass 44,886 189 45,075 — 45,075 Special Mention 301 — 301 — 301 Substandard 80 — 80 — 80 Total commercial and industrial loans 45,267 189 45,456 — 45,456 December 31, 2019 Performing (Accruing) Loans 0-29 Days Past Due 30-89 Days Past Due Total Non-Performing Loans Total Loans Receivable, net Other loans Pass 2,058 26 2,084 — 2,084 Total other loans 2,058 26 2,084 — 2,084 Total originated loans held-for-investment 2,980,106 3,753 2,983,859 3,208 2,987,067 Acquired loans: One-to-four family residential LTV < 60% Pass 172,882 73 172,955 — 172,955 Special Mention — 385 385 — 385 Substandard — — — 426 426 Total 172,882 458 173,340 426 173,766 LTV => 60% Pass 14,116 — 14,116 — 14,116 Substandard — — — 93 93 Total 14,116 — 14,116 93 14,209 Total one-to-four family residential 186,998 458 187,456 519 187,975 Commercial LTV < 35% Pass 35,173 287 35,460 — 35,460 Special Mention 994 194 1,188 — 1,188 Substandard 369 — 369 334 703 Total 36,536 481 37,017 334 37,351 LTV => 35% Pass 60,311 — 60,311 — 60,311 Special Mention 134 464 598 — 598 Substandard 6,382 2,960 9,342 5,425 14,767 Total 66,827 3,424 70,251 5,425 75,676 Total commercial 103,363 3,905 107,268 5,759 113,027 Construction and land Pass 2,537 — 2,537 — 2,537 Total construction and land 2,537 — 2,537 — 2,537 Multifamily LTV < 35% Pass 105,327 — 105,327 — 105,327 Substandard — — — 40 40 Total 105,327 — 105,327 40 105,367 LTV => 35% Pass 2,653 — 2,653 — 2,653 Substandard — — — 397 397 Total 2,653 — 2,653 397 3,050 Total multifamily 107,980 — 107,980 437 108,417 Home equity and lines of credit Pass 11,842 50 11,892 — 11,892 Substandard 88 — 88 28 116 Total home equity and lines of credit 11,930 50 11,980 28 12,008 Commercial and industrial Pass 8,649 40 8,689 — 8,689 Total commercial and industrial 8,649 40 8,689 — 8,689 Other — — — — — Total loans acquired 421,457 4,453 425,910 6,743 432,653 $ 3,401,563 $ 8,206 $ 3,409,769 $ 9,951 $ 3,419,720 December 31, 2018 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 $ 78,699 $ 218 $ 78,917 $ — $ 78,917 Special Mention — 395 395 — 395 Total 78,699 613 79,312 — 79,312 LTV => 35% Pass 408,830 325 409,155 — 409,155 Special Mention 1,137 — 1,137 — 1,137 Substandard 7,381 — 7,381 2,875 10,256 Total 417,348 325 417,673 2,875 420,548 Total commercial 496,047 938 496,985 2,875 499,860 One-to-four family residential LTV < 60% Pass 54,576 336 54,912 — 54,912 Special Mention — 747 747 — 747 Substandard 896 — 896 510 1,406 Total 55,472 1,083 56,555 510 57,065 LTV => 60% Pass 34,576 232 34,808 — 34,808 Substandard 528 — 528 32 560 Total 35,104 232 35,336 32 35,368 Total one-to-four family residential 90,576 1,315 91,891 542 92,433 Construction and land Pass 26,613 — 26,613 — 26,613 Total construction and land 26,613 — 26,613 — 26,613 Multifamily LTV < 35% Pass 170,534 298 170,832 — 170,832 Total 170,534 298 170,832 — 170,832 LTV => 35% Pass 1,756,443 439 1,756,882 — 1,756,882 Special Mention 613 — 613 — 613 Substandard 4,390 1,229 5,619 — 5,619 Total 1,761,446 1,668 1,763,114 — 1,763,114 Total multifamily 1,931,980 1,966 1,933,946 — 1,933,946 Home equity and lines of credit Pass 80,077 — 80,077 — 80,077 Special Mention 27 — 27 — 27 Substandard 137 — 137 74 211 Total home equity and lines of credit 80,241 — 80,241 74 80,315 Commercial and industrial loans Pass 43,640 — 43,640 — 43,640 Special Mention 430 — 430 — 430 Substandard 95 — 95 25 120 Total Commercial and industrial loans 44,165 — 44,165 25 44,190 Other loans Pass 1,518 2 1,520 — 1,520 Total other loans 1,518 2 1,520 — 1,520 Total originated loans held-for-investment 2,671,140 4,221 2,675,361 3,516 2,678,877 December 31, 2018 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 202,471 2,799 205,270 — 205,270 Special Mention 415 — 415 — 415 Substandard 62 6 68 374 442 Total 202,948 2,805 205,753 374 206,127 LTV => 60% Pass 19,504 — 19,504 — 19,504 Substandard — — — 246 246 Total 19,504 — 19,504 246 19,750 Total one-to-four family residential 222,452 2,805 225,257 620 225,877 Commercial LTV < 35% Pass 41,071 — 41,071 — 41,071 Special Mention 1,079 — 1,079 — 1,079 Substandard 1,185 151 1,336 281 1,617 Total 43,335 151 43,486 281 43,767 LTV => 35% Pass 73,986 749 74,735 — 74,735 Special Mention 4,315 128 4,443 — 4,443 Substandard 5,772 411 6,183 4,135 10,318 Total 84,073 1,288 85,361 4,135 89,496 Total commercial 127,408 1,439 128,847 4,416 133,263 Construction and land Substandard 12,003 — 12,003 — 12,003 Total construction and land 12,003 — 12,003 — 12,003 Multifamily LTV < 35% Pass 137,141 — 137,141 — 137,141 Special Mention — 52 52 — 52 Substandard — — — 152 152 Total 137,141 52 137,193 152 137,345 LTV => 35% Pass 7,726 — 7,726 — 7,726 Special Mention — — — 414 414 Total 7,726 — 7,726 414 8,140 Total multifamily 144,867 52 144,919 566 145,485 Home equity and lines of credit Pass 17,427 — 17,427 — 17,427 Substandard 79 — 79 77 156 Total home equity and lines of credit 17,506 — 17,506 77 17,583 Commercial and industrial loans Pass 11,888 45 11,933 — 11,933 Total Commercial and industrial loans 11,888 45 11,933 — 11,933 Other loans Pass 6 — 6 — 6 Total loans acquired 536,130 4,341 540,471 5,679 546,150 $ 3,207,270 $ 8,562 $ 3,215,832 $ 9,195 $ 3,225,027
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, 2019 , and December 31, 2018 (in thousands): December 31, 2019 December 31, 2018 Average Recorded Investment Interest Income Average Recorded Investment Interest Income With No Allowance Recorded: Real estate loans: Commercial LTV => 35% Pass $ 5,757 $ 312 $ 5,218 $ 255 Substandard 11,012 237 10,582 404 One-to-four family residential LTV < 60% Pass 1,586 66 1,403 62 Special Mention 155 23 — Substandard 302 29 246 12 One-to-four family residential LTV => 60% Pass 125 4 186 7 Substandard 81 8 129 13 Multifamily LTV < 35% Substandard 64 2 152 6 LTV => 35% Pass 32 15 296 16 Substandard 1,075 61 987 67 Home equity and lines of credit Pass 25 1 31 2 Commercial and industrial loans Substandard 45 — 100 — With a Related Allowance Recorded: Real estate loans: Commercial LTV => 35% Pass — — 880 76 Substandard 991 17 267 — One-to-four family residential LTV < 60% Pass — 164 Substandard 338 — 733 19 LTV => 60% Pass — — 54 Home equity and lines of credit Substandard 33 2 34 2 Commercial and industrial loans Special Mention 20 1 23 1 Total: Real estate loans: Commercial 17,760 566 16,947 735 One-to-four family residential 2,587 130 2,915 113 Multifamily 1,171 78 1,435 89 Home equity and lines of credit 58 3 65 4 Commercial and industrial loans 65 1 123 1 $ 21,641 $ 778 $ 21,485 $ 942 The following table summarizes originated and acquired (subsequent to acquisition) impaired loans as of December 31, 2019 and 2018 (in thousands): At December 31, 2019 December 31, 2018 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 5,582 6,468 — 5,931 6,817 — Substandard 10,438 11,002 — 12,160 15,028 — One-to-four family residential LTV < 60% Pass 1,379 1,463 — 1,532 1,606 — Special Mention 385 385 — — — — Substandard 564 564 — 241 241 — LTV => 60% Pass 122 154 — 129 158 — Substandard 29 29 — 126 278 — Multifamily LTV < 35% Substandard 40 40 — 152 152 — LTV => 35% Pass 26 496 — 38 509 — Substandard 972 972 — 1,229 1,229 — Home Equity Pass 22 22 — 28 28 — Commercial and industrial loans Substandard 39 39 — 52 119 — With a Related Allowance Recorded: Real estate loans: Commercial LTV => 35% Substandard 1,307 1,307 (135 ) — — — One-to-four family residential LTV < 60% Substandard — — — 657 657 (18 ) LTV => 60% Pass — — — — — — Home equity and lines of credit Substandard 33 33 (3 ) 33 33 (5 ) Commercial and industrial loans Special Mention 19 19 (4 ) 21 21 (3 ) Total: Real estate loans: Commercial 17,327 18,916 (135 ) 18,091 21,984 — One-to-four family residential 2,479 2,595 — 2,685 2,940 (18 ) Multifamily 1,038 1,508 — 1,419 1,890 — Home equity and lines of credit 55 55 (3 ) 61 61 (5 ) Commercial and industrial loans 58 $ 58 (4 ) 73 140 (3 ) $ 20,957 $ 23,132 $ (142 ) $ 22,329 $ 27,015 $ (26 )
Troubled Debt Restructurings on Financing Receivables	The following table summarizes loans that were modified in a TDR during the year ended December 31, 2019 : Number of Relationships Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment (1) (Dollars in thousands) Troubled Debt Restructurings Consumer 1 $ 2 $ 2 Commercial real estate 1 2,834 2,834 Total Troubled Debt Restructurings 2 $ 2,836 $ 2,836 (1) Amounts are at time of modification

Premises and Equipment, Net (Ta

Premises and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Premises and Equipment Less Accumulated Depreciation and Amortization	At December 31, 2019 and 2018 , premises and equipment, less accumulated depreciation and amortization, consists of the following (in thousands): December 31, 2019 2018 At cost: Land $ 4,018 $ 4,018 Buildings and improvements 10,660 8,905 Capital leases 2,600 2,600 Furniture, fixtures, and equipment 26,179 24,140 Leasehold improvements 27,886 30,115 71,343 69,778 Accumulated depreciation and amortization (45,684 ) (44,173 ) Premises and equipment, net $ 25,659 $ 25,605

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Deposit Account Balances	Deposit account balances are summarized as follows (dollars in thousands): As of December 31, 2019 2018 Amount Weighted Average Rate Amount Weighted Average Rate Transaction: Negotiable orders of withdrawal and interest-bearing checking $ 573,927 0.87 % $ 458,012 0.68 % Non-interest bearing checking 387,409 — % 395,375 — % Total transaction 961,336 0.52 % 853,387 0.36 % Savings: Money market 651,159 1.18 % 741,939 1.12 % Savings 747,186 1.02 % 594,290 0.90 % Total savings 1,398,345 1.09 % 1,336,229 1.02 % Certificates of deposit: Under $100,000 563,303 1.86 % 599,245 1.91 % $100,000 or more 485,249 1.98 % 497,651 2.01 % Total certificates of deposit 1,048,552 1.92 % 1,096,896 1.96 % Total deposits $ 3,408,233 1.18 % $ 3,286,512 1.16 %
Maturities of Certificates of Deposit	Scheduled maturities of certificates of deposit are summarized as follows (in thousands): December 31, 2019 2020 $ 908,744 2021 46,856 2022 49,075 2023 35,008 2024 8,869 Total $ 1,048,552
Interest Expense on Deposits	Interest expense on deposits is summarized as follows (in thousands): Years Ended December 31, 2019 2018 2017 Transaction $ 4,623 $ 2,175 $ 1,429 Savings 15,850 8,878 6,804 Certificates of deposit 20,855 16,688 8,153 $ 41,328 $ 27,741 $ 16,386

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Summary of Borrowings	Borrowings consisted of FHLB advances, securities sold under agreements to repurchase (repurchase agreements), and floating rate advances and are summarized as follows (in thousands): December 31, 2019 2018 Repurchase agreements $ 75,000 $ — Other borrowings: FHLB advances 776,000 403,502 Floating rate advances 6,004 5,345 Obligations under capital leases — 44 $ 857,004 $ 408,891
Contractual Maturities Repurchase Agreements and FHLB Advances	FHLB advances and repurchase agreements have contractual maturities as follows (in thousands): December 31, 2019 FHLB Repurchase Advances Agreements 2020 $ 411,000 $ — 2021 145,000 25,000 2022 95,000 25,000 2023 87,500 — 2024 25,000 25,000 Thereafter 12,500 — $ 776,000 $ 75,000 Further information regarding FHLB advances and repurchase agreements is summarized as follows (in thousands): December 31, 2019 2018 2019 2018 FHLB Advances Repurchase Agreements Average balance during year $ 518,372 $ 448,012 $ 45,342 $ — Maximum outstanding at any month end $ 776,000 $ 475,582 $ 75,000 $ — Weighted average interest rate at end of year 2.04 % 1.95 % 2.30 % — % Weighted average interest rate during year 2.08 % 1.82 % 2.35 % — %
Summary of Interest Expense on Borrowings	Interest expense on borrowings is summarized as follows (in thousands): Years Ended December 31, 2019 2018 2017 Repurchase agreements $ 1,065 $ 7 $ 137 FHLB advances 10,795 8,172 7,390 Floating rate advances 170 123 33 Obligations under capital leases — 7 30 $ 12,030 $ 8,309 $ 7,590

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	Income tax expense (benefit) consists of the following (in thousands): Years Ended December 31, 2019 2018 2017 Federal tax expense (benefit): Current $ 8,543 $ 8,540 $ 10,113 Deferred 376 (742 ) 14,290 8,919 7,798 24,403 State and local tax expense (benefit): Current 4,067 1,985 1,672 Deferred (199 ) (151 ) 903 3,868 1,834 2,575 Total income tax expense $ 12,787 $ 9,632 $ 26,978
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, 2019 , 2018 , and 2017 , is as follows (dollars in thousands): Years Ended December 31, 2019 2018 2017 Tax expense at statutory rate $ 11,135 $ 10,439 $ 18,111 Applicable statutory federal income tax rate 21 % 21 % 35 % Increase (decrease) in taxes resulting from: State tax, net of federal income tax 3,056 1,448 1,674 Impact of 2017 federal tax reform — — 10,453 Bank owned life insurance (1,475 ) (778 ) (1,885 ) ESOP fair market value adjustment 187 196 404 Incentive stock options 81 146 247 Uncertain tax position — — 132 Excess tax benefits from employee share based payments (110 ) (1,939 ) (2,309 ) Other, net (87 ) 120 151 Income tax expense $ 12,787 $ 9,632 $ 26,978
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, 2019 and 2018 , are as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Allowance for loan losses $ 7,985 $ 7,317 Capitalized leases — 13 Deferred compensation 3,498 3,426 Accrued salaries 738 737 Postretirement benefits 376 375 Equity awards 2,164 3,045 Unrealized actuarial losses on post-retirement benefits (21 ) 18 Straight-line rent 1,277 1,051 Asset retirement obligation 70 67 Reserve for accrued interest receivable 578 602 Reserve for loan commitments 216 146 Employee Stock Ownership Plan 615 551 Other 244 261 Depreciation 2,414 2,383 Fair value adjustments of acquired loans 3,713 3,934 Fair value adjustments of pension benefit obligations 160 154 Unrealized losses on debt securities available-for-sale — 3,575 Total gross deferred tax assets 24,027 27,655 Deferred tax liabilities: Unrealized gains on debt securities available for sale 1,786 — Fair value adjustments of acquired securities 20 28 Fair value adjustments of deposit liabilities 219 285 Deferred loan fees 2,224 1,984 Other 30 33 Total gross deferred tax liabilities 4,279 2,330 Net deferred tax asset $ 19,748 $ 25,325
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the Company’s uncertain tax positions are as follows (in thousands): December 31, 2019 2018 2017 Beginning balance $ 530 $ 482 $ 459 Settlements based on tax positions related to prior years (530 ) (238 ) (109 ) Additions based on tax positions related to prior years 190 286 132 Ending balance $ 190 $ 530 $ 482

Retirement Benefits (Tables)

Retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2019
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): 2019 2018 2017 Accumulated postretirement benefit obligation beginning of year $ 1,359 $ 1,645 $ 1,697 Service cost 9 11 11 Interest cost 52 52 57 Actuarial (gain) loss (76 ) (229 ) (8 ) Benefits paid (103 ) (120 ) (112 ) Accumulated postretirement benefit obligation end of year 1,241 1,359 1,645 Accrued liability (included in accrued expenses and other liabilities) $ 1,241 $ 1,359 $ 1,645
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, 2019 2018 Net loss $ 132 $ 20 Prior service credit (191 ) — (Gain) loss recognized in accumulated other comprehensive income (loss) $ (59 ) $ 20
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, 2019 , 2018 , and 2017 (in thousands): December 31, 2019 2018 2017 Service cost $ 9 $ 11 $ 11 Interest cost 52 52 57 Amortization of unrecognized loss 2 25 28 Net postretirement benefit cost included in compensation and employee benefits $ 63 $ 88 $ 96
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: 2019 2018 2017 Assumptions used to determine benefit obligation at period end: Discount rate 2.75 % 4.00 % 3.25 % Rate of increase in compensation 4.00 % 4.00 % 4.00 % Assumptions used to determine net periodic benefit cost for the year: Discount rate 4.00 % 3.25 % 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 2019 2018 2019 2018 Effect on benefits earned and interest cost $ 4 $ 4 $ (4 ) $ (3 ) Effect on accumulated postretirement benefit obligation $ 104 $ 109 $ (90 ) $ (94 ) 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 2019 2018 2017 2019 2018 2017 Aggregate of service and interest components of net periodic cost (benefit) $ 4 $ 4 $ 4 $ (4 ) $ (3 ) $ (4 )

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Valuation Assumptions	The fair value of stock options granted in 2017 was estimated utilizing the Black-Scholes option pricing model using the following assumptions: Year Ended December 31, 2017 Grant Date November 1, 2017 September 19, 2017 August 1, 2017 Stock options granted 40,000 12,500 45,744 Risk-free rate of return 2.06 % 1.89 % 1.86 % Volatility 29.22 % 30.06 % 29.46 % Dividend yield 2.37 % 1.98 % 1.91 % Expected life 5.75 5.75 5.75
Stock Options Outstanding	The following table is a summary of the Company’s non-vested stock options as of December 31, 2019 , 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, 2017 4,620,687 $ 3.51 $ 11.82 5.17 Forfeited (29,378 ) 3.36 11.51 — Exercised (1,339,714 ) 2.49 7.75 — Outstanding- December 31, 2018 3,251,595 3.93 13.51 5.62 Forfeited (15,000 ) 4.07 14.76 — Exercised (1,009,402 ) 3.75 12.54 — Outstanding - December 31, 2019 2,227,193 4.01 13.93 4.96 Exercisable - December 31, 2019 2,046,272 $ 3.99 $ 13.83 4.91
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, 2019 , and changes therein during the year then ended: Number of Shares Awarded Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 585,895 $ 14.05 Granted 15,000 16.48 Vested (266,973 ) 13.86 Forfeited (4,960 ) 14.18 Non-vested at December 31, 2018 328,962 14.31 Vested (249,860 ) 13.99 Forfeited (8,000 ) 14.76 Non-vested at December 31, 2019 71,102 $ 15.36

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingent Liabilities Not Reflected in Consolidated Financial Statements	At December 31, 2019 and 2018 , the following commitment and contingent liabilities existed that are not reflected in the accompanying consolidated financial statements (in thousands): December 31, 2019 2018 Commitments to extend credit $ 125,630 $ 39,326 Unused lines of credit 143,164 136,586 Standby letters of credit 6,713 5,352

Regulatory Requirements (Tables

Regulatory Requirements (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 , 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, 2019: Common Equity Tier 1 Capital (to risk-weighted assets) $ 598,462 14.99 % $ 179,626 4.50 % $ 259,459 6.50 % Tier 1 Leverage 598,462 12.28 194,954 4.00 243,692 5.00 Tier I capital (to risk-weighted assets) 598,462 14.99 239,501 6.00 319,334 8.00 Total capital (to risk-weighted assets) 627,955 15.73 319,334 8.00 399,168 10.00 As of December 31, 2018: Common Equity Tier 1 Capital (to risk-weighted assets) $ 592,815 16.00 % $ 166,742 4.50 % $ 240,850 6.50 % Tier 1 Leverage 592,815 13.81 171,663 4.00 214,579 5.00 Tier I capital (to risk-weighted assets) 592,815 16.00 222,323 6.00 296,430 8.00 Total capital (to risk-weighted assets) 620,863 16.76 296,430 8.00 370,538 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, 2019 and 2018 , for classification as well-capitalized 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, 2019: Common Equity Tier 1 Capital (to risk-weighted assets) $ 651,974 16.35 % $ 179,439 4.50 % $ 259,189 6.50 % Tier 1 Leverage 651,974 13.37 195,018 4.00 243,772 5.00 Tier I capital (to risk-weighted assets) 651,974 16.35 239,251 6.00 319,002 8.00 Total capital (to risk-weighted assets) 681,467 17.09 319,002 8.00 398,752 10.00 As of December 31, 2018: Common Equity Tier 1 Capital (to risk-weighted assets) $ 636,141 17.17 % $ 166,717 4.50 % $ 240,814 6.50 % Tier 1 Leverage 636,141 14.82 171,724 4.00 214,656 5.00 Tier I capital (to risk-weighted assets) 636,141 17.17 222,290 6.00 296,386 8.00 Total capital (to risk-weighted assets) 664,190 17.93 296,386 8.00 370,483 10.00

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 , 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, 2019 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: Debt securities available-for-sale: Mortgage-backed securities: Pass-through certificates: GSE $ 329,407 $ — $ 329,407 $ — REMICs: GSE 643,667 — 643,667 — Non-GSE 53 — 53 — 973,127 — 973,127 — Other debt securities: Municipal bonds 299 — 299 Corporate bonds 164,926 — 164,926 — 165,225 — 165,225 — Total debt securities available-for-sale 1,138,352 — 1,138,352 — Trading securities 11,222 11,222 — — Equity securities 250 250 — — Total 1,149,824 11,472 1,138,352 — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 4,871 $ — $ — $ 4,871 Multifamily 26 — — 26 Home equity and lines of credit 30 — — 30 Total impaired real estate loans 4,927 — — 4,927 Commercial and industrial loans 15 — — 15 Total $ 4,942 $ — $ — $ 4,942 Fair Value Measurements at December 31, 2018 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: Debt securities available-for-sale: Mortgage-backed securities: Pass-through certificates: GSE $ 314,788 $ — $ 314,788 $ — REMICs: GSE 250,163 — 250,163 — Non-GSE 58 — 58 — 565,009 — 565,009 — Other debt securities: Municipal Bonds 273 — 273 — Corporate bonds 242,749 — 242,749 — 243,022 — 243,022 — Total debt securities available-for sale 808,031 — 808,031 — Trading securities 8,968 8,968 — — Equity securities - mutual funds 237 237 — — Total $ 817,236 $ 9,205 $ 808,031 $ — Measured on a non-recurring basis: Assets: Impaired loans: Real estate loans: Commercial real estate $ 4,847 $ — $ — $ 4,847 One-to-four family residential mortgage 765 — — 765 Multifamily 39 — — 39 Home equity and lines of credit 28 — — 28 Total impaired real estate loans 5,679 — — 5,679 Commercial and industrial loans 18 — — 18 Total $ 5,697 $ — $ — $ 5,697
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, 2018 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 5,697 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 4.13% - 6.25% The following table presents qualitative information for Level 3 assets measured at fair value on a non-recurring basis at December 31, 2019 : Fair Value Valuation Methodology Unobservable Inputs Range of Inputs (in thousands) Impaired loans $ 4,942 Appraisals Discount for costs to sell 7.0% Discount for quick sale 10.0% Discounted cash flows Interest rates 4.13% - 6.25%
Estimated Fair Values of Significant Financial Instruments	The estimated fair values of the Company’s significant financial instruments at December 31, 2019 and 2018 , are presented in the following table (in thousands): December 31, 2019 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 147,818 $ 147,818 $ — $ — $ 147,818 Trading securities 11,222 11,222 — — 11,222 Debt securities available-for-sale 1,138,352 — 1,138,352 — 1,138,352 Debt securities held-to-maturity 8,762 — 8,886 — 8,886 Equity securities (1) 250 250 — — 250 FHLB of New York stock, at cost 39,575 — 39,575 — 39,575 Net loans held-for-investment 3,408,378 — — 3,482,804 3,482,804 Financial liabilities: Deposits $ 3,408,233 $ — $ 3,412,414 $ — $ 3,412,414 Repurchase agreements, FHLB advances and other borrowings 857,004 — 862,980 — 862,980 Advance payments by borrowers 44,069 — 44,069 — 44,069 December 31, 2018 Estimated Fair Value Carrying Value Level 1 Level 2 Level 3 Total Financial assets: Cash and cash equivalents $ 77,762 $ 77,762 $ — $ — $ 77,762 Trading securities 8,968 8,968 — — 8,968 Debt securities available-for-sale 808,031 — 808,031 — 808,031 Debt securities held-to-maturity 9,505 — 9,249 — 9,249 Equity securities (1) 237 237 — — 237 FHLB of New York stock, at cost 22,517 — 22,517 — 22,517 Net loans held-for-investment 3,217,673 — — 3,236,136 3,236,136 Financial liabilities: Deposits $ 3,286,512 $ — $ 3,291,085 $ — $ 3,291,085 Repurchase agreements, FHLB advances and other borrowings 408,891 — 403,476 — 403,476 Advance payments by borrowers 18,007 — 18,007 — 18,007 (1) Excludes $3.1 million and $1.0 million of investments measured at net asset value at December 31, 2019 and 2018, respectively, which have not been classified in the fair value hierarchy.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
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 (dollars in thousands, except share and per share data): December 31, 2019 2018 2017 Net income available to common stockholders $ 40,235 $ 40,079 $ 24,768 Weighted average shares outstanding-basic 46,783,442 46,319,760 45,325,445 Effect of non-vested restricted stock and stock options outstanding 380,362 787,673 1,550,285 Weighted average shares outstanding-diluted 47,163,804 47,107,433 46,875,730 Earnings per share-basic $ 0.86 $ 0.87 $ 0.55 Earnings per share-diluted $ 0.85 $ 0.85 $ 0.53 Anti-dilutive shares 546,120 765,792 334,927

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Schedule of Non-Interest Income	The following table summarizes non-interest income for the years indicated (dollars in thousands): December 31, 2019 2018 2017 Fees and service charges for customer services: Service charges $ 3,309 $ 3,356 $ 3,320 ATM and card interchange fees 1,310 1,216 1,150 Investment fees 262 305 232 Total fees and service charges for customer services 4,881 4,877 4,702 Income on bank owned life insurance (1) 7,023 3,705 5,386 Gains (losses) on available-for-sale debt securities, net (1) 1,988 (879 ) 1,114 Gains on trading securities, net (1) 514 178 169 Other (1) 402 246 271 Total non-interest income $ 14,808 $ 8,127 $ 11,642 (1) Not within the scope of Topic 606

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lease, Cost	Supplemental lease information at or for the year ended December 31, 2019 is as follows (dollars in thousands): Operating lease cost $ 6,698 Variable lease cost 2,813 Net lease cost $ 9,511 Cash paid for amounts included in measurement of operating lease liabilities $ 5,901 Right-of-use assets obtained in exchange for new operating lease liabilities $ 1,013 Weighted average remaining lease term (in years) at December 31, 2019 12.77 Weighted average discount rate at December 31, 2019 3.62 %
Lessee, Operating Lease, Liability, Maturity	The following table summarizes lease payment obligations for each of the next five years and thereafter in addition to a reconcilement to the Company's current lease liability (dollars in thousands): Year Amount 2020 $ 6,160 2021 5,730 2022 5,068 2023 4,975 2024 4,629 Thereafter 30,668 Total lease payments $ 57,230 Less: imputed interest (13,161 ) Present value of lease liabilities $ 44,069

Parent-only Financial Informa_2

Parent-only Financial Information (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	Northfield Bancorp, Inc. Condensed Balance Sheets December 31, 2019 2018 (in thousands) Assets Cash in Northfield Bank $ 32,828 $ 21,884 Interest-earning deposits in other financial institutions 280 21 Investment in Northfield Bank 642,341 623,113 ESOP loan receivable 21,897 22,962 Other assets 132 120 Total assets $ 697,478 $ 668,100 Liabilities and Stockholders' Equity Total liabilities $ 1,625 $ 1,661 Total stockholders' equity 695,853 666,439 Total liabilities and stockholders' equity $ 697,478 $ 668,100
Condensed Statements of Comprehensive Income (Loss)	Northfield Bancorp, Inc. Condensed Statements of Comprehensive Income Years Ended December 31, 2019 2018 2017 (in thousands) Interest on ESOP loan $ 1,263 $ 1,081 $ 939 Interest income on deposits in other financial institutions 229 38 31 Gains (losses) gains on securities, net 10 (6 ) 5 Undistributed earnings of Northfield Bank 40,012 40,092 24,887 Total income 41,514 41,205 25,862 Other expenses 863 890 872 Income tax expense 416 236 222 Total expense 1,279 1,126 1,094 Net income $ 40,235 $ 40,079 $ 24,768 Comprehensive income: Net income $ 40,235 $ 40,079 $ 24,768 Other comprehensive income (loss), net of tax 13,846 (3,696 ) (227 ) Comprehensive income $ 54,081 $ 36,383 $ 24,541
Condensed Statements of Cash Flows	Northfield Bancorp, Inc. Condensed Statements of Cash Flows Years Ended December 31, 2019 2018 2017 (in thousands) Cash flows from operating activities Net income $ 40,235 $ 40,079 $ 24,768 Adjustments to reconcile net income to net cash (used in) provided by operating activities: (Increase) decrease in other assets (1,073 ) 3 (2,008 ) (Gains) losses on securities, net (10 ) 6 (5 ) (Decrease) increase in other liabilities (36 ) 846 (980 ) Undistributed earnings of Northfield Bank (40,012 ) (40,092 ) (24,887 ) Net cash (used in) provided by operating activities (896 ) 842 (3,112 ) Cash flows from investing activities Dividends from Northfield Bank 41,277 16,493 28,763 Net cash provided by investing activities 41,277 16,493 28,763 Cash flows from financing activities Principal payments on ESOP loan receivable 1,065 1,059 1,022 Purchase of treasury stock (15,815 ) (5 ) — Dividends paid (20,198 ) (18,673 ) (15,646 ) Exercise of stock options 5,770 2,088 100 Net cash used in financing activities (29,178 ) (15,531 ) (14,524 ) Net increase in cash and cash equivalents 11,203 1,804 11,127 Cash and cash equivalents at beginning of year 21,905 20,101 8,974 Cash and cash equivalents at end of year $ 33,108 $ 21,905 $ 20,101

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	The following tables are a summary of certain quarterly financial data for the years ended December 31, 2019 and 2018 : 2019 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 39,466 $ 40,193 $ 42,847 $ 42,637 Interest expense 12,136 13,034 14,027 14,161 Net interest income 27,330 27,159 28,820 28,476 Provision (recoveries) for loan losses 59 491 (1,300 ) 772 Net interest income after provision for loan losses 27,271 26,668 30,120 27,704 Other income 3,314 2,566 4,733 4,195 Other expenses 19,204 18,750 16,869 18,726 Income before income tax expense 11,381 10,484 17,984 13,173 Income tax expense 2,610 2,280 4,845 3,052 Net income $ 8,771 $ 8,204 $ 13,139 $ 10,121 Net income per basic common share $ 0.19 $ 0.18 $ 0.28 $ 0.22 Net income per diluted common share $ 0.19 $ 0.17 $ 0.28 $ 0.21 2018 Quarter Ended March 31 June 30 September 30 December 31 (Dollars in thousands, except per share data) Selected Operating Data: Interest income $ 34,682 $ 35,935 $ 37,727 $ 38,948 Interest expense 7,138 8,165 9,803 10,944 Net interest income 27,544 27,770 27,924 28,004 Provision for loan losses 34 670 1,304 607 Net interest income after provision for loan losses 27,510 27,100 26,620 27,397 Other income 2,405 2,445 2,637 640 Other expenses 17,126 17,040 17,100 15,777 Income before income tax expense 12,789 12,505 12,157 12,260 Income tax expense 2,344 1,893 3,081 2,314 Net income $ 10,445 $ 10,612 $ 9,076 $ 9,946 Net income per basic common share $ 0.23 $ 0.23 $ 0.19 $ 0.21 Net income per diluted common share $ 0.22 $ 0.23 $ 0.19 $ 0.21

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Schedule Of Significant Accounting Policies [Line Items]
Minimum amount of non-accrual loans individually evaluated for impairment	$ 20,957,000	$ 22,329,000
Delinquent status classification term	90 days
Threshold of membership investment component, percentage	0.125%
Threshold of membership investment component	$ 1,000
Activity based investment component as a percentage of outstanding advances	4.50%
Goodwill	$ 38,411,000	$ 38,411,000
ESOP repayment period (years)	30 years
Effect of non-vested restricted stock and stock options outstanding	380,362	787,673	1,550,285
Operating lease right-of-use assets	$ 39,504,000
Operating lease liabilities	44,069,000
Minimum
Schedule Of Significant Accounting Policies [Line Items]
Minimum amount of non-accrual loans individually evaluated for impairment	$ 500,000
ASU 2018-02
Schedule Of Significant Accounting Policies [Line Items]
Reclassification of tax effects resulting from the adoption of ASU No. 2018-02			$ 0
ASU 2018-02 | Retained Earnings
Schedule Of Significant Accounting Policies [Line Items]
Reclassification of tax effects resulting from the adoption of ASU No. 2018-02			$ 892,000
ASU 2016-02
Schedule Of Significant Accounting Policies [Line Items]
Operating lease right-of-use assets				$ 43,600,000
Operating lease liabilities				$ 47,300,000
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

Debt Securities Available-for_3

Debt Securities Available-for-Sale - Comparative Summary of Mortgage-Backed Securities and Other Securities Available-for-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized cost	$ 1,131,970	$ 820,801
Gross unrealized gains	9,374	967
Gross unrealized losses	2,992	13,737
Estimated fair value	1,138,352	808,031
Pass-through certificates | GSE
Debt Securities, Available-for-sale [Line Items]
Amortized cost	324,080	317,530
Gross unrealized gains	6,081	800
Gross unrealized losses	754	3,542
Estimated fair value	329,407	314,788
REMICs
Debt Securities, Available-for-sale [Line Items]
Amortized cost	967,949	575,639
Gross unrealized gains	8,157	892
Gross unrealized losses	2,979	11,522
Estimated fair value	973,127	565,009
REMICs | GSE
Debt Securities, Available-for-sale [Line Items]
Amortized cost	643,816	258,050
Gross unrealized gains	2,076	92
Gross unrealized losses	2,225	7,979
Estimated fair value	643,667	250,163
REMICs | Non-GSE
Debt Securities, Available-for-sale [Line Items]
Amortized cost	53	59
Gross unrealized gains	0	0
Gross unrealized losses	0	1
Estimated fair value	53	58
Other debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized cost	164,021	245,162
Gross unrealized gains	1,217	75
Gross unrealized losses	13	2,215
Estimated fair value	165,225	243,022
Other debt securities | Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Amortized cost	296	270
Gross unrealized gains	3	3
Gross unrealized losses	0	0
Estimated fair value	299	273
Other debt securities | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized cost	163,725	244,892
Gross unrealized gains	1,214	72
Gross unrealized losses	13	2,215
Estimated fair value	$ 164,926	$ 242,749

Debt Securities Available-for_4

Debt 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, 2019	Dec. 31, 2018
Amortized cost
Amortized cost	$ 1,131,970	$ 820,801
Estimated fair value
Estimated fair value	1,138,352	$ 808,031
Other Than Mortgage Backed Securities
Amortized cost
Due in one year or less	75,115
Due after one year through five years	88,906
Amortized cost	164,021
Estimated fair value
Due in one year or less	75,353
Due after one year through five years	89,872
Estimated fair value	$ 165,225

Debt Securities Available-for_5

Debt Securities Available-for-Sale - Narrative (Details)	12 Months Ended
	Dec. 31, 2019USD ($)security	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Securities, Available-for-sale [Line Items]
Carrying value of securities available-for-sale | $	$ 730,900,000	$ 492,400,000
Gross proceeds on sales of securities | $	79,255,000	32,115,000	$ 4,975,000
Gross realized gains | $	514,000	183,000	173,000
Gross realized losses | $	0	5,000	4,000
Net gains (losses) on trading securities portfolio | $	2,000,000	(879,000)	1,100,000
Other-than-temporary impairment charges on debt securities available-for-sale | $	$ 0	$ 0	$ 0
Non-GSE | REMIC
Debt Securities, Available-for-sale [Line Items]
Number of debt securities, unrealized loss position longer than 12 months	1
Corporate bonds | REMIC
Debt Securities, Available-for-sale [Line Items]
Number of debt securities, unrealized loss position longer than 12 months	4
Pass-through | GSE | REMIC
Debt Securities, Available-for-sale [Line Items]
Number of debt securities, unrealized loss position longer than 12 months	28
Pass-through | GSE | Pass-through certificates
Debt Securities, Available-for-sale [Line Items]
Number of debt securities, unrealized loss position less than 12 months	3
Non Pass-through | GSE | REMIC
Debt Securities, Available-for-sale [Line Items]
Number of debt securities, unrealized loss position longer than 12 months	20
Number of debt securities, unrealized loss position less than 12 months	23
Internal Investment Grade | Non-GSE | REMIC
Debt Securities, Available-for-sale [Line Items]
Number of debt securities, unrealized loss position longer than 12 months	1

Debt Securities Available-for_6

Debt Securities Available-for-Sale - Gross Unrealized Losses on Mortgage-Backed Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Unrealized losses, Less than 12 months	$ 975	$ 2,376
Estimated fair value, Less than 12 months	201,038	302,921
Unrealized losses, 12 months or more	2,017	11,361
Estimated fair value, 12 months or more	125,378	307,354
Unrealized losses, Total	2,992	13,737
Estimated fair value, Total	326,416	610,275
Pass-through certificates | GSE
Debt Securities, Available-for-sale [Line Items]
Unrealized losses, Less than 12 months	25	404
Estimated fair value, Less than 12 months	3,404	82,781
Unrealized losses, 12 months or more	729	3,138
Estimated fair value, 12 months or more	55,184	100,109
Unrealized losses, Total	754	3,542
Estimated fair value, Total	58,588	182,890
REMICs | GSE
Debt Securities, Available-for-sale [Line Items]
Unrealized losses, Less than 12 months	950	269
Estimated fair value, Less than 12 months	197,634	46,921
Unrealized losses, 12 months or more	1,275	7,710
Estimated fair value, 12 months or more	54,555	181,512
Unrealized losses, Total	2,225	7,979
Estimated fair value, Total	252,189	228,433
REMICs | Non-GSE
Debt Securities, Available-for-sale [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	0	1
Estimated fair value, 12 months or more	53	58
Unrealized losses, Total	0	1
Estimated fair value, Total	53	58
Other debt securities | Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Unrealized losses, Less than 12 months	0	1,703
Estimated fair value, Less than 12 months	0	173,219
Unrealized losses, 12 months or more	13	512
Estimated fair value, 12 months or more	15,586	25,675
Unrealized losses, Total	13	2,215
Estimated fair value, Total	$ 15,586	$ 198,894

Debt Securities Held-to-Matur_3

Debt Securities Held-to-Maturity - Summary of Mortgage-Backed Securities Held-to-Maturity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 8,762,000	$ 9,505,000
Gross Unrealized Gains	129,000	0
Gross Unrealized Losses	5,000	256,000
Estimated Fair Value	8,886,000	9,249,000
Sales of held-to-maturity securities	0	0	$ 0
Held-to-maturity securities pledged to secured repurchase agreements and deposits	7,400,000	6,500,000
Mortgage-Backed Securities, Pass-Through Certificates
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	8,762,000	9,505,000
Gross Unrealized Gains	129,000	0
Gross Unrealized Losses	5,000	256,000
Estimated Fair Value	$ 8,886,000	$ 9,249,000

Debt Securities Held-to-Matur_4

Debt Securities Held-to-Maturity - Unrealized Losses and Estimated Fair Value (Details)	12 Months Ended
	Dec. 31, 2019USD ($)security	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Unrealized losses
Less than 12 months	$ 0	$ 34,000
12 months or more	5,000	222,000
Total	5,000	256,000
Estimated fair value
Less than 12 months	0	2,133,000
12 months or more	378,000	7,116,000
Total	378,000	9,249,000
Other-than-temporary impairment charges on securities held-to-maturity	0	0	$ 0
Mortgage-Backed Securities, Pass-Through Certificates
Unrealized losses
Less than 12 months	0	34,000
12 months or more	5,000	222,000
Total	5,000	256,000
Estimated fair value
Less than 12 months	0	2,133,000
12 months or more	378,000	7,116,000
Total	$ 378,000	$ 9,249,000
Number of held-to-maturity securities in an unrealized loss position, greater than twelve months | security	1

Equity Securities (Details)

Equity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt and Equity Securities, FV-NI [Line Items]
Equity securities	$ 3,341	$ 1,280
Equity securities without readily determinable fair value	3,100	1,000
Money Market Funds
Debt and Equity Securities, FV-NI [Line Items]
Equity securities, fair value	250	237
SBA Loan Fund
Debt and Equity Securities, FV-NI [Line Items]
Equity securities without readily determinable fair value	$ 3,100	$ 1,000

Loans - Net Loans Held-for-Inve

Loans - Net Loans Held-for-Investment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Loans held-for-investment, net	$ 3,437,085	$ 3,245,170
PCI Loans	17,365	20,143
Allowance for loan losses	(28,707)	(27,497)	$ (26,160)	$ (24,595)
Net loans held-for-investment	3,408,378	3,217,673
Originated loans
Loans and Leases Receivable Disclosure [Line Items]
Total commercial and industrial and other loans	47,411	45,623
Deferred loan cost, net	7,614	6,892
Loans held-for-investment, net	2,987,067	2,678,877
Allowance for loan losses	(27,783)	(26,487)	(25,172)
Originated loans | Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,932,042	2,626,362
Originated loans | Real Estate | Multifamily
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,196,407	1,930,535
Loans held-for-investment, net	2,199,734	1,933,946
Allowance for loan losses	(20,203)	(18,084)	(17,374)
Originated loans | Real Estate | Commercial mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	528,681	499,311
Loans held-for-investment, net	529,287	499,860
Allowance for loan losses	(4,756)	(5,630)	(5,196)
Originated loans | Real Estate | One-to-four family residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	83,742	91,371
Loans held-for-investment, net	85,355	92,433
Allowance for loan losses	(180)	(342)	(503)
Originated loans | Real Estate | Home equity and lines of credit
Loans and Leases Receivable Disclosure [Line Items]
Loans	84,928	78,593
Loans held-for-investment, net	86,848	80,315
Allowance for loan losses	(317)	(291)	(122)
Originated loans | Real Estate | Construction and land
Loans and Leases Receivable Disclosure [Line Items]
Loans	38,284	26,552
Loans held-for-investment, net	38,303	26,613
Allowance for loan losses	(536)	(463)	(610)
Originated loans | Commercial and Industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	45,328	44,104
Loans held-for-investment, net	45,456	44,190
Allowance for loan losses	(1,640)	(1,569)	(1,273)
Originated loans | Other
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,083	1,519
Loans held-for-investment, net	2,084	1,520
Allowance for loan losses	(151)	(108)	(94)
Acquired Loans
Loans and Leases Receivable Disclosure [Line Items]
Loans	432,653	546,150
Loans held-for-investment, net	432,653	546,150
Allowance for loan losses	(135)	0	$ (37)
Acquired Loans | Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Loans	423,964	534,211
Acquired Loans | Real Estate | Multifamily
Loans and Leases Receivable Disclosure [Line Items]
Loans	108,417	145,485
Acquired Loans | Real Estate | Commercial mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	113,027	133,263
Acquired Loans | Real Estate | One-to-four family residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	187,975	225,877
Acquired Loans | Real Estate | Home equity and lines of credit
Loans and Leases Receivable Disclosure [Line Items]
Loans	12,008	17,583
Acquired Loans | Real Estate | Construction and land
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,537	12,003
Acquired Loans | Commercial and Industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	8,689	11,933
Acquired Loans | Other
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 0	$ 6

Loans - Narrative, PCI Loans (D

Loans - Narrative, PCI Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of loans held for sale	$ 0	$ 0
PCI loans held-for-investment	3,437,085,000	3,245,170,000
Principal balance of loans on non accrual status	$ 2,600,000	$ 3,200,000
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased credit-impaired (PCI) loan percent	29.00%	27.00%
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased credit-impaired (PCI) loan percent	42.00%	50.00%
PCI
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI loans held-for-investment	$ 17,365,000	$ 20,143,000
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance of loans on non accrual status	$ 500,000

Loans - Summary Of Accretable Y

Loans - Summary Of Accretable Yield (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at the beginning of year	$ 21,846	$ 24,502
Accretion into interest income	(4,142)	(4,176)
Net reclassification from non-accretable difference	(618)	1,520
Balance at end of year	$ 17,086	$ 21,846

Loans - Activity In The Allowan

Loans - Activity In The Allowance For Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for loan losses:
Beginning Balance	$ 27,497	$ 26,160	$ 24,595
Provision for loan losses	22	2,615	1,411
Recoveries	2,175	112	556
Charge-offs	(987)	(1,390)	(402)
Ending Balance	$ 28,707	$ 27,497	$ 26,160

Loans - Amount of Loans Receiva

Loans - Amount of Loans Receivable Held-for-Investment and Related Allowances Per Loan Portfolio Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for loan losses:
Beginning Balance	$ 27,497	$ 26,160	$ 24,595
Charge-offs	(987)	(1,390)	(402)
Recoveries	2,175	112	556
Provisions (credit)	22	2,615	1,411
Ending Balance	28,707	27,497	26,160
Ending balance: individually evaluated for impairment	142	26
Ending balance: collectively evaluated for impairment	28,565	27,471
Loans, net:
Loans held-for-investment, net	3,437,085	3,245,170
Ending balance: individually evaluated for impairment	20,957	22,329
Ending balance: collectively evaluated for impairment	3,416,128	3,222,841
Originated Loans Total
Allowance for loan losses:
Beginning Balance	26,487	25,172
Charge-offs	(743)	(1,389)
Recoveries	2,009	99
Provisions (credit)	30	2,605
Ending Balance	27,783	26,487	25,172
Ending balance: individually evaluated for impairment	7	26
Ending balance: collectively evaluated for impairment	27,776	26,461
Loans, net:
Loans held-for-investment, net	2,987,067	2,678,877
Ending balance: individually evaluated for impairment	16,177	18,547
Ending balance: collectively evaluated for impairment	2,970,890	2,660,330
PCI
Allowance for loan losses:
Beginning Balance	1,010	951
Charge-offs	0	0
Recoveries	0	0
Provisions (credit)	(221)	59
Ending Balance	789	1,010	951
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	789	1,010
Loans, net:
Loans held-for-investment, net	17,365	20,143
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	17,365	20,143
Acquired Loans
Allowance for loan losses:
Beginning Balance	0	37
Charge-offs	(244)	(1)
Recoveries	166	13
Provisions (credit)	213	(49)
Ending Balance	135	0	37
Ending balance: individually evaluated for impairment	135	0
Ending balance: collectively evaluated for impairment	0	0
Loans, net:
Loans held-for-investment, net	432,653	546,150
Ending balance: individually evaluated for impairment	4,780	3,782
Ending balance: collectively evaluated for impairment	427,873	542,368
Real Estate | Commercial mortgage | Originated Loans Total
Allowance for loan losses:
Beginning Balance	5,630	5,196
Charge-offs	(520)	(1,256)
Recoveries	98	49
Provisions (credit)	(452)	1,641
Ending Balance	4,756	5,630	5,196
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	4,756	5,630
Loans, net:
Loans held-for-investment, net	529,287	499,860
Ending balance: individually evaluated for impairment	13,226	15,252
Ending balance: collectively evaluated for impairment	516,061	484,608
Real Estate | One-to-Four Family | Originated Loans Total
Allowance for loan losses:
Beginning Balance	342	503
Charge-offs	0	(3)
Recoveries	72	4
Provisions (credit)	(234)	(162)
Ending Balance	180	342	503
Ending balance: individually evaluated for impairment	0	18
Ending balance: collectively evaluated for impairment	180	324
Loans, net:
Loans held-for-investment, net	85,355	92,433
Ending balance: individually evaluated for impairment	1,841	1,893
Ending balance: collectively evaluated for impairment	83,514	90,540
Real Estate | Construction and Land | Originated Loans Total
Allowance for loan losses:
Beginning Balance	463	610
Charge-offs	0	0
Recoveries	0	0
Provisions (credit)	73	(147)
Ending Balance	536	463	610
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	536	463
Loans, net:
Loans held-for-investment, net	38,303	26,613
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	38,303	26,613
Real Estate | Multifamily | Originated Loans Total
Allowance for loan losses:
Beginning Balance	18,084	17,374
Charge-offs	0	0
Recoveries	1,818	26
Provisions (credit)	301	684
Ending Balance	20,203	18,084	17,374
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	20,203	18,084
Loans, net:
Loans held-for-investment, net	2,199,734	1,933,946
Ending balance: individually evaluated for impairment	997	1,268
Ending balance: collectively evaluated for impairment	2,198,737	1,932,678
Real Estate | Home Equity and Lines of Credit | Originated Loans Total
Allowance for loan losses:
Beginning Balance	291	122
Charge-offs	0	(60)
Recoveries	0	0
Provisions (credit)	26	229
Ending Balance	317	291	122
Ending balance: individually evaluated for impairment	3	5
Ending balance: collectively evaluated for impairment	314	286
Loans, net:
Loans held-for-investment, net	86,848	80,315
Ending balance: individually evaluated for impairment	55	61
Ending balance: collectively evaluated for impairment	86,793	80,254
Commercial and Industrial | Originated Loans Total
Allowance for loan losses:
Beginning Balance	1,569	1,273
Charge-offs	(100)	(70)
Recoveries	20	20
Provisions (credit)	151	346
Ending Balance	1,640	1,569	1,273
Ending balance: individually evaluated for impairment	4	3
Ending balance: collectively evaluated for impairment	1,636	1,566
Loans, net:
Loans held-for-investment, net	45,456	44,190
Ending balance: individually evaluated for impairment	58	73
Ending balance: collectively evaluated for impairment	45,398	44,117
Other | Originated Loans Total
Allowance for loan losses:
Beginning Balance	108	94
Charge-offs	(123)	0
Recoveries	1	0
Provisions (credit)	165	14
Ending Balance	151	108	$ 94
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	151	108
Loans, net:
Loans held-for-investment, net	2,084	1,520
Ending balance: individually evaluated for impairment	0	0
Ending balance: collectively evaluated for impairment	$ 2,084	$ 1,520

Loans - Narrative, Loan-to-Valu

Loans - Narrative, Loan-to-Value Ratios (Details)	Dec. 31, 2019
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 by Loan Type and Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	$ 2,987,067	$ 2,678,877
Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	2,968,346	2,657,356
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	2,850	3,349
Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	15,871	18,172
Real Estate | Multifamily | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	233,251	170,832
Real Estate | Multifamily | Less Than 35% LTV | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	232,950	170,832
Real Estate | Multifamily | Less Than 35% LTV | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Real Estate | Multifamily | Less Than 35% LTV | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	301	0
Real Estate | Multifamily | Equal to or Greater than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,966,483	1,763,114
Real Estate | Multifamily | Equal to or Greater than 35% LTV | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,960,984	1,756,882
Real Estate | Multifamily | Equal to or Greater than 35% LTV | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	296	613
Real Estate | Multifamily | Equal to or Greater than 35% LTV | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	5,203	5,619
Real Estate | Commercial | Less Than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	79,855	79,312
Real Estate | Commercial | Less Than 35% LTV | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	79,485	78,917
Real Estate | Commercial | Less Than 35% LTV | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	370	395
Real Estate | Commercial | Less Than 35% LTV | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Real Estate | Commercial | Equal to or Greater than 35% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	449,432	420,548
Real Estate | Commercial | Equal to or Greater than 35% LTV | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	440,065	409,155
Real Estate | Commercial | Equal to or Greater than 35% LTV | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,092	1,137
Real Estate | Commercial | Equal to or Greater than 35% LTV | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	8,275	10,256
Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	55,060	57,065
Real Estate | One-to-four family residential mortgage | Less Than 60% LTV | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	52,886	54,912
Real Estate | One-to-four family residential mortgage | Less Than 60% LTV | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	777	747
Real Estate | One-to-four family residential mortgage | Less Than 60% LTV | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	1,397	1,406
Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	30,295	35,368
Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	29,967	34,808
Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	328	560
Real Estate | Construction and Land
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	38,303	26,613
Real Estate | Construction and Land | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	38,303	26,613
Real Estate | Construction and Land | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Real Estate | Construction and Land | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Real Estate | Home Equity and Lines of Credit
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	86,848	80,315
Real Estate | Home Equity and Lines of Credit | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	86,547	80,077
Real Estate | Home Equity and Lines of Credit | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	14	27
Real Estate | Home Equity and Lines of Credit | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	287	211
Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	45,456	44,190
Commercial and Industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	45,075	43,640
Commercial and Industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	301	430
Commercial and Industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	80	120
Other
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	2,084	1,520
Other | Pass
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	2,084	1,520
Other | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Originated loans held-for-investment, net	0	0
Other | 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, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment in non accrual loans	$ 9,400,000	$ 9,200,000
Delinquent status classification term	90 days
Impairment of loans	$ 6,800,000	5,900,000
Principal balance of loans on non accrual status	2,600,000	3,200,000
Loans held-for-sale non accrual amount	0	0
Loans past 90 days and still accruing	518,000	33,000
Loans with carrying balances not written down	15,900,000	$ 16,600,000
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance of loans on non accrual status	$ 500,000

Loans - PCI Loan Pools (Details

Loans - PCI Loan Pools (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
90 Days or More Past Due and Accruing	$ 518	$ 33
Total Loans Receivable, net	2,987,067	2,678,877
Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	9,433	9,162
90 Days or More Past Due and Accruing	518	33
Total Non-Performing Loans	9,951	9,195
Non-Performing Loans | Loans held-for-investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,094	3,516
90 Days or More Past Due and Accruing	114	0
Total Non-Performing Loans	3,208	3,516
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	493
90 Days or More Past Due and Accruing	114
Total Non-Performing Loans	607
Non-Performing Loans | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,416
90 Days or More Past Due and Accruing	0
Total Non-Performing Loans	2,416
Non-Performing Loans | Loans held-for-investment | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		2,875
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		2,875
Non-Performing Loans | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	522	541
90 Days or More Past Due and Accruing	114	0
Total Non-Performing Loans	636	541
Non-Performing Loans | Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	156	75
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	156	75
Non-Performing Loans | Loans held-for-investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		25
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		25
Non-Performing Loans | Loans acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	6,339	5,646
90 Days or More Past Due and Accruing	404	33
Total Non-Performing Loans	6,743	5,679
Non-Performing Loans | Loans acquired | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	275
90 Days or More Past Due and Accruing	151
Total Non-Performing Loans	426
Non-Performing Loans | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	5,506	4,416
90 Days or More Past Due and Accruing	253	0
Total Non-Performing Loans	5,759	4,416
Non-Performing Loans | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	368	587
90 Days or More Past Due and Accruing	151	33
Total Non-Performing Loans	519	620
Non-Performing Loans | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	437	566
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	437	566
Non-Performing Loans | Loans acquired | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	28	77
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	28	77
Non-Performing Loans | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,416
90 Days or More Past Due and Accruing	0
Total Non-Performing Loans	2,416
Non-Performing Loans | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		2,875
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		2,875
Non-Performing Loans | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	493	509
90 Days or More Past Due and Accruing	114	0
Total Non-Performing Loans	607	509
Non-Performing Loans | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	29	32
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	29	32
Non-Performing Loans | Substandard | Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	156	75
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	156	75
Non-Performing Loans | Substandard | Loans held-for-investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		25
90 Days or More Past Due and Accruing		0
Total Non-Performing Loans		25
Non-Performing Loans | Substandard | Loans acquired | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	267	281
90 Days or More Past Due and Accruing	66	0
Total Non-Performing Loans	333	281
Non-Performing Loans | Substandard | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	5,239	4,135
90 Days or More Past Due and Accruing	187	0
Total Non-Performing Loans	5,426	4,135
Non-Performing Loans | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	275	368
90 Days or More Past Due and Accruing	151	6
Total Non-Performing Loans	426	374
Non-Performing Loans | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	93	219
90 Days or More Past Due and Accruing	0	27
Total Non-Performing Loans	93	246
Non-Performing Loans | Substandard | Loans acquired | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	40	152
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	40	152
Non-Performing Loans | Substandard | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	397	414
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	397	414
Non-Performing Loans | Substandard | Loans acquired | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	28	77
90 Days or More Past Due and Accruing	0	0
Total Non-Performing Loans	28	77
Non-Performing Loans | 0-29 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,839	440
Non-Performing Loans | 0-29 Days Past Due | Loans held-for-investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	75
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	0
Non-Performing Loans | 0-29 Days Past Due | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% 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 | Real Estate | Commercial mortgage | Equal to or Greater than 35% 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 | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
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 | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	75
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 acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,839	365
Non-Performing Loans | 0-29 Days Past Due | Loans acquired | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	190
Non-Performing Loans | 0-29 Days Past Due | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,609	87
Non-Performing Loans | 0-29 Days Past Due | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	190	126
Non-Performing Loans | 0-29 Days Past Due | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	40	152
Non-Performing Loans | 0-29 Days Past Due | Loans acquired | Real Estate | 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 | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		0
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	75
Non-Performing Loans | 0-29 Days Past Due | Substandard | 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 | Substandard | Loans acquired | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	79	87
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	3,530	0
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	190	0
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	126
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans acquired | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	40	152
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 0-29 Days Past Due | Substandard | Loans acquired | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	493	2,128
Non-Performing Loans | 30-89 Days Past Due | Loans held-for-investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	96	751
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	0
Non-Performing Loans | 30-89 Days Past Due | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% 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 | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		287
Non-Performing Loans | 30-89 Days Past Due | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	29	464
Non-Performing Loans | 30-89 Days Past Due | Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	67	0
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 acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	397	1,377
Non-Performing Loans | 30-89 Days Past Due | Loans acquired | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 30-89 Days Past Due | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	764
Non-Performing Loans | 30-89 Days Past Due | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	199
Non-Performing Loans | 30-89 Days Past Due | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	397	414
Non-Performing Loans | 30-89 Days Past Due | Loans acquired | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		287
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	432
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	29	32
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	67	0
Non-Performing Loans | 30-89 Days Past Due | Substandard | 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 | Substandard | Loans acquired | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	764
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	199
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans acquired | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	397	414
Non-Performing Loans | 30-89 Days Past Due | Substandard | Loans acquired | Real Estate | 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
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	5,101	6,594
Non-Performing Loans | 90 Days or More Past Due | Loans held-for-investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,998	2,690
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	493
Non-Performing Loans | 90 Days or More Past Due | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,416
Non-Performing Loans | 90 Days or More Past Due | Loans held-for-investment | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		2,588
Non-Performing Loans | 90 Days or More Past Due | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	493	77
Non-Performing Loans | 90 Days or More Past Due | Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	89	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		25
Non-Performing Loans | 90 Days or More Past Due | Loans acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,103	3,904
Non-Performing Loans | 90 Days or More Past Due | Loans acquired | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	85
Non-Performing Loans | 90 Days or More Past Due | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	1,897	3,565
Non-Performing Loans | 90 Days or More Past Due | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	178	262
Non-Performing Loans | 90 Days or More Past Due | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Loans acquired | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	28	77
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	2,416
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans held-for-investment | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		2,588
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	493	77
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	89	0
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans held-for-investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans		25
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans acquired | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	188	194
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	1,709	3,371
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	85	169
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	93	93
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans acquired | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	0	0
Non-Performing Loans | 90 Days or More Past Due | Substandard | Loans acquired | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accruing Loans	$ 28	$ 77

Loans - Loans Held-for-Investme

Loans - Loans Held-for-Investment by Performing and Non-Performing Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	$ 2,987,067	$ 2,678,877
Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	9,433	9,162
Non-Performing Loans	9,951	9,195
Total Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	3,419,720	3,225,027
Total Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,409,769	3,215,832
Total Loans | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	9,951	9,195
Loans held-for-investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	2,987,067	2,678,877
Loans held-for-investment | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	2,084	1,520
Loans held-for-investment | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	2,084	1,520
Loans held-for-investment | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	529,287	499,860
Loans held-for-investment | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	79,855	79,312
Loans held-for-investment | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	449,432	420,548
Loans held-for-investment | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	79,485	78,917
Loans held-for-investment | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	440,065	409,155
Loans held-for-investment | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	8,275	10,256
Loans held-for-investment | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	370	395
Loans held-for-investment | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	1,092	1,137
Loans held-for-investment | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	85,355	92,433
Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	55,060	57,065
Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	30,295	35,368
Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	52,886	54,912
Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	29,967	34,808
Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	1,397	1,406
Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	328	560
Loans held-for-investment | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	777	747
Loans held-for-investment | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	38,303	26,613
Loans held-for-investment | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	38,303	26,613
Loans held-for-investment | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	2,199,734	1,933,946
Loans held-for-investment | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	233,251	170,832
Loans held-for-investment | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	1,966,483	1,763,114
Loans held-for-investment | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	232,950	170,832
Loans held-for-investment | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	1,960,984	1,756,882
Loans held-for-investment | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	5,203	5,619
Loans held-for-investment | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	296	613
Loans held-for-investment | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	86,848	80,315
Loans held-for-investment | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	86,547	80,077
Loans held-for-investment | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	287	211
Loans held-for-investment | Real Estate | Home equity and lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	14	27
Loans held-for-investment | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	45,456	44,190
Loans held-for-investment | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	45,075	43,640
Loans held-for-investment | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	80	120
Loans held-for-investment | Commercial and Industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	301	430
Loans held-for-investment | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,983,859	2,675,361
Loans held-for-investment | Performing (Accruing) Loans | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	301
Loans held-for-investment | Performing (Accruing) Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,084	1,520
Loans held-for-investment | Performing (Accruing) Loans | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,084	1,520
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	526,871	496,985
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	79,855	79,312
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	447,016	417,673
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	79,485	78,917
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	440,065	409,155
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	5,859	7,381
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	370	395
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,092	1,137
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	84,719	91,891
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	54,453	56,555
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	30,266	35,336
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	52,886	54,912
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	29,967	34,808
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	790	896
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	299	528
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	777	747
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	38,303	26,613
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	38,303	26,613
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,199,734	1,933,946
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	233,251	170,832
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,966,483	1,763,114
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	232,950	170,832
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,960,984	1,756,882
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	5,203	5,619
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	296	613
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	86,692	80,241
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	86,547	80,077
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	131	137
Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	14	27
Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	45,456	44,165
Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	45,075	43,640
Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	80	95
Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	301	430
Loans held-for-investment | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	3,208	3,516
Loans held-for-investment | Non-Performing Loans | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0
Total Loans Receivable, net	301
Loans held-for-investment | Non-Performing Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	2,416	2,875
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	2,416	2,875
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	2,416	2,875
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	636	542
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	607	510
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	29	32
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	607	510
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	29	32
Loans held-for-investment | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	156	74
Loans held-for-investment | Non-Performing Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	156	74
Loans held-for-investment | Non-Performing Loans | Real Estate | Home equity and lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	25
Loans held-for-investment | Non-Performing Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans held-for-investment | Non-Performing Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	25
Loans held-for-investment | Non-Performing Loans | Commercial and Industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	432,653	546,150
Loans acquired | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net		6
Loans acquired | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	0
Loans acquired | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	113,027	133,263
Loans acquired | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	37,351	43,767
Loans acquired | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	75,676	89,496
Loans acquired | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	35,460	41,071
Loans acquired | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	60,311	74,735
Loans acquired | Real Estate | Commercial mortgage | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	703	1,617
Loans acquired | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	14,767	10,318
Loans acquired | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	1,188	1,079
Loans acquired | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	598	4,443
Loans acquired | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	187,975	225,877
Loans acquired | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	173,766	206,127
Loans acquired | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	14,209	19,750
Loans acquired | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	172,955	205,270
Loans acquired | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	14,116	19,504
Loans acquired | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	426	442
Loans acquired | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	93	246
Loans acquired | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	385	415
Loans acquired | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	2,537	12,003
Loans acquired | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	2,537
Loans acquired | Real Estate | Construction and land | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net		12,003
Loans acquired | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	108,417	145,485
Loans acquired | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	105,367	137,345
Loans acquired | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	3,050	8,140
Loans acquired | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	105,327	137,141
Loans acquired | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	2,653	7,726
Loans acquired | Real Estate | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	40	152
Loans acquired | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	397
Loans acquired | Real Estate | Multifamily | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net		52
Loans acquired | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net		414
Loans acquired | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	12,008	17,583
Loans acquired | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	11,892	17,427
Loans acquired | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	116	156
Loans acquired | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	8,689	11,933
Loans acquired | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable, net	8,689	11,933
Loans acquired | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	425,910	540,471
Loans acquired | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		6
Loans acquired | Performing (Accruing) Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	107,268	128,847
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	37,017	43,486
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	70,251	85,361
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	35,460	41,071
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	60,311	74,735
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	369	1,336
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	9,342	6,183
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,188	1,079
Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	598	4,443
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	187,456	225,257
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	173,340	205,753
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	14,116	19,504
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	172,955	205,270
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	14,116	19,504
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	68
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	385	415
Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,537	12,003
Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,537
Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		12,003
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	107,980	144,919
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	105,327	137,193
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,653	7,726
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	105,327	137,141
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,653	7,726
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		52
Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	11,980	17,506
Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	11,892	17,427
Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	88	79
Loans acquired | Performing (Accruing) Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,689	11,933
Loans acquired | Performing (Accruing) Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,689	11,933
Loans acquired | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	6,743	5,679
Loans acquired | Non-Performing Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Loans acquired | Non-Performing Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	5,759	4,416
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	334	281
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	5,425	4,135
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	334	281
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	5,425	4,135
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	519	620
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	426	374
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	93	246
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	426	374
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	93	246
Loans acquired | Non-Performing Loans | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0
Loans acquired | Non-Performing Loans | Real Estate | Construction and land | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Loans acquired | Non-Performing Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	437	566
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	40	152
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	397	414
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	40	152
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	397
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		0
Loans acquired | Non-Performing Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans		414
Loans acquired | Non-Performing Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	28	77
Loans acquired | Non-Performing Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	28	77
Loans acquired | Non-Performing Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
Loans acquired | Non-Performing Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Performing Loans	0	0
0-29 Days Past Due | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,839	440
0-29 Days Past Due | Total Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,401,563	3,207,270
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,980,106	2,671,140
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	301
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,058	1,518
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,058	1,518
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	525,326	496,047
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	79,753	78,699
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	445,573	417,348
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	79,383	78,699
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	439,253	408,830
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	5,228	7,381
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	370	0
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,092	1,137
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	83,587	90,576
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	53,547	55,472
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	30,040	35,104
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	52,757	54,576
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	29,741	34,576
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	790	896
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	299	528
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | 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 | Performing (Accruing) Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	38,156	26,613
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	38,156	26,613
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,199,187	1,931,980
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	232,959	170,534
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,966,228	1,761,446
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	232,658	170,534
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,960,729	1,756,443
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	5,203	4,390
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	296	613
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	86,525	80,241
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	86,380	80,077
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	131	137
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	14	27
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	45,267	44,165
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	44,886	43,640
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	80	95
0-29 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	301	430
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	421,457	536,130
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		6
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	103,363	127,408
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	36,536	43,335
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	66,827	84,073
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	35,173	41,071
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	60,311	73,986
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	369	1,185
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	6,382	5,772
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	994	1,079
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	134	4,315
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	186,998	222,452
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	172,882	202,948
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	14,116	19,504
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	172,882	202,471
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	14,116	19,504
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	62
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	415
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,537	12,003
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,537
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		12,003
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	107,980	144,867
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	105,327	137,141
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,653	7,726
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	105,327	137,141
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,653	7,726
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	11,930	17,506
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	11,842	17,427
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	88	79
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,649	11,888
0-29 Days Past Due | Loans acquired | Performing (Accruing) Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,649	11,888
30-89 Days Past Due | Non-Performing Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	493	2,128
30-89 Days Past Due | Total Loans | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	8,206	8,562
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,753	4,221
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Multifamily | 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 | Performing (Accruing) Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	26	2
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	26	2
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,545	938
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	102	613
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,443	325
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	102	218
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	812	325
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	631	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	395
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	1,132	1,315
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	906	1,083
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	226	232
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	129	336
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	226	232
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	777	747
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	147	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	147	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	547	1,966
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	292	298
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	255	1,668
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	292	298
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	255	439
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	1,229
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	167	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	167	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	189	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	189	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans held-for-investment | Performing (Accruing) Loans | Commercial and Industrial | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	4,453	4,341
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,905	1,439
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	481	151
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	3,424	1,288
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	287	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	749
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	151
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	2,960	411
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	194	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Commercial mortgage | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	464	128
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	458	2,805
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	458	2,805
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	73	2,799
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Pass | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	6
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Substandard | Equal to or Greater than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | One-to-four family residential mortgage | Special Mention | Less Than 60% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	385	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Construction and land | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	52
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	52
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Pass | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Substandard | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Less Than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		52
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Multifamily | Special Mention | Equal to or Greater than 35% LTV
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans		0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	50	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	50	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Real Estate | Home equity and lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	0	0
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	40	45
30-89 Days Past Due | Loans acquired | Performing (Accruing) Loans | Commercial and Industrial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Performing (Accruing) Loans	$ 40	$ 45

Loans - Summary of Impaired Loa

Loans - Summary of Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 20,957	$ 22,329
Unpaid Principal Balance	23,132	27,015
Related Allowance	(142)	(26)
Real Estate | Commercial mortgage
Financing Receivable, Impaired [Line Items]
Recorded Investment	17,327	18,091
Unpaid Principal Balance	18,916	21,984
Related Allowance	(135)	0
Real Estate | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Recorded Investment	2,479	2,685
Unpaid Principal Balance	2,595	2,940
Related Allowance	0	(18)
Real Estate | Multifamily
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,038	1,419
Unpaid Principal Balance	1,508	1,890
Related Allowance	0	0
Real Estate | Home equity and lines of credit
Financing Receivable, Impaired [Line Items]
Recorded Investment	55	61
Unpaid Principal Balance	55	61
Related Allowance	(3)	(5)
Real Estate | Home equity and lines of credit | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With a Related Allowance Recorded	33	33
Unpaid Principal Balance With a Related Allowance Recorded	33	33
Related Allowance	(3)	(5)
Real Estate | Home equity and lines of credit | Pass
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	22	28
Unpaid Principal Balance With No Related Allowance Recorded	22	28
Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Recorded Investment	58	73
Unpaid Principal Balance	58	140
Related Allowance	(4)	(3)
Commercial and Industrial | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	39	52
Unpaid Principal Balance With No Related Allowance Recorded	39	119
Commercial and Industrial | Special Mention
Financing Receivable, Impaired [Line Items]
Recorded Investment With a Related Allowance Recorded	19	21
Unpaid Principal Balance With a Related Allowance Recorded	19	21
Related Allowance	(4)	(3)
Less Than 35% LTV | Real Estate | Commercial mortgage | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	0	0
Unpaid Principal Balance With No Related Allowance Recorded	139	139
Less Than 35% LTV | Real Estate | Multifamily | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	40	152
Unpaid Principal Balance With No Related Allowance Recorded	40	152
Equal to or Greater than 35% LTV | Real Estate | Commercial mortgage | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	10,438	12,160
Recorded Investment With a Related Allowance Recorded	1,307	0
Unpaid Principal Balance With No Related Allowance Recorded	11,002	15,028
Unpaid Principal Balance With a Related Allowance Recorded	1,307	0
Related Allowance	(135)	0
Equal to or Greater than 35% LTV | Real Estate | Commercial mortgage | Pass
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	5,582	5,931
Unpaid Principal Balance With No Related Allowance Recorded	6,468	6,817
Equal to or Greater than 35% LTV | Real Estate | Multifamily | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	972	1,229
Unpaid Principal Balance With No Related Allowance Recorded	972	1,229
Equal to or Greater than 35% LTV | Real Estate | Multifamily | Pass
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	26	38
Unpaid Principal Balance With No Related Allowance Recorded	496	509
Less Than 60% LTV | One-to-four family residential mortgage | Special Mention
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded		0
Unpaid Principal Balance With No Related Allowance Recorded		0
Less Than 60% LTV | Real Estate | One-to-four family residential mortgage | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	564	241
Recorded Investment With a Related Allowance Recorded	0	657
Unpaid Principal Balance With No Related Allowance Recorded	564	241
Unpaid Principal Balance With a Related Allowance Recorded	0	657
Related Allowance	0	(18)
Less Than 60% LTV | Real Estate | One-to-four family residential mortgage | Pass
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	1,379	1,532
Unpaid Principal Balance With No Related Allowance Recorded	1,463	1,606
Less Than 60% LTV | Real Estate | One-to-four family residential mortgage | Special Mention
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	385
Unpaid Principal Balance With No Related Allowance Recorded	385
Equal to or Greater than 60% LTV | Real Estate | One-to-four family residential mortgage | Substandard
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	29	126
Unpaid Principal Balance With No Related Allowance Recorded	29	278
Equal to or Greater than 60% LTV | Real Estate | One-to-four family residential mortgage | Pass
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Allowance Recorded	122	129
Recorded Investment With a Related Allowance Recorded	0	0
Unpaid Principal Balance With No Related Allowance Recorded	154	158
Unpaid Principal Balance With a Related Allowance Recorded	0	0
Related Allowance	$ 0	$ 0

Loans - Average Recorded Invest

Loans - Average Recorded Investment and Interest Recognized on Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 21,641	$ 21,485
Interest Income	778	942
Real Estate | Commercial mortgage
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	17,760	16,947
Interest Income	566	735
Real Estate | One-to-four family residential mortgage
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	2,587	2,915
Interest Income	130	113
Real Estate | Multifamily
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,171	1,435
Interest Income	78	89
Real Estate | Home equity and lines of credit
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	58	65
Interest Income	3	4
Real Estate | Home equity and lines of credit | Substandard
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With a Related Allowance Recorded	33	34
Interest Income With a Related Allowance Recorded	2	2
Real Estate | Home equity and lines of credit | Pass
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	25	31
Interest Income With No Allowance Recorded	1	2
Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	65	123
Interest Income	1	1
Commercial and Industrial | Substandard
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	45	100
Interest Income With No Allowance Recorded	0	0
Commercial and Industrial | Special Mention
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With a Related Allowance Recorded	20	23
Interest Income With a Related Allowance Recorded	1	1
Less Than 35% LTV | Real Estate | Multifamily | Substandard
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	64	152
Interest Income With No Allowance Recorded	2	6
Equal to or Greater than 35% LTV | Real Estate | Commercial mortgage | Substandard
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	11,012	10,582
Average Recorded Investment With a Related Allowance Recorded	991	267
Interest Income With No Allowance Recorded	237	404
Interest Income With a Related Allowance Recorded	17	0
Equal to or Greater than 35% LTV | Real Estate | Commercial mortgage | Pass
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	5,757	5,218
Average Recorded Investment With a Related Allowance Recorded	0	880
Interest Income With No Allowance Recorded	312	255
Interest Income With a Related Allowance Recorded	0	76
Equal to or Greater than 35% LTV | Real Estate | Multifamily | Substandard
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	1,075	987
Interest Income With No Allowance Recorded	61	67
Equal to or Greater than 35% LTV | Real Estate | Multifamily | Pass
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	32	296
Interest Income With No Allowance Recorded	15	16
Less Than 60% LTV | Real Estate | One-to-four family residential mortgage | Substandard
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	302	246
Average Recorded Investment With a Related Allowance Recorded	338	733
Interest Income With No Allowance Recorded	29	12
Interest Income With a Related Allowance Recorded	0	19
Less Than 60% LTV | Real Estate | One-to-four family residential mortgage | Pass
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	1,586	1,403
Average Recorded Investment With a Related Allowance Recorded	0	164
Interest Income With No Allowance Recorded	66	62
Interest Income With a Related Allowance Recorded
Less Than 60% LTV | Real Estate | One-to-four family residential mortgage | Special Mention
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	155	0
Interest Income With No Allowance Recorded	23
Equal to or Greater than 60% LTV | Real Estate | One-to-four family residential mortgage | Substandard
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	81	129
Interest Income With No Allowance Recorded	8	13
Equal to or Greater than 60% LTV | Real Estate | One-to-four family residential mortgage | Pass
Financing Receivable, Impaired [Line Items]
Average Recorded Investment With No Allowance Recorded	125	186
Average Recorded Investment With a Related Allowance Recorded	0	54
Interest Income With No Allowance Recorded	4	7
Interest Income With a Related Allowance Recorded	$ 0

Loans - Summary of Loans Modifi

Loans - Summary of Loans Modified in a TDR (Details)	12 Months Ended
	Dec. 31, 2019USD ($)contract	Dec. 31, 2018USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Relationships	2	1
Pre-Modification Outstanding Recorded Investment	$ 2,836,000
Post-Modification Outstanding Recorded Investment	$ 2,836,000
One-to-four family residential mortgage
Financing Receivable, Modifications [Line Items]
Number of Relationships | contract	1
Pre-Modification Outstanding Recorded Investment	$ 2,000	$ 6,400
Post-Modification Outstanding Recorded Investment	$ 2,000
Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Relationships | contract	1
Pre-Modification Outstanding Recorded Investment	$ 2,834,000
Post-Modification Outstanding Recorded Investment	$ 2,834,000

Loans - Narrative, TDR (Details

Loans - Narrative, TDR (Details)	12 Months Ended
	Dec. 31, 2019USD ($)contractloan	Dec. 31, 2018USD ($)loan
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	$ 18,500,000	$ 16,900,000
Number of loans modified as TDR that subsequently defaulted | loan	2
Number of loans modified as TDR	2	1
Pre-modification outstanding recorded investment	$ 2,836,000
One-to-four family residential mortgage
Financing Receivable, Modifications [Line Items]
Number of loans modified as TDR | contract	1
Pre-modification outstanding recorded investment	$ 2,000	$ 6,400

Premises and Equipment, Net - P

Premises and Equipment, Net - Premises and Equipment Less Accumulated Depreciation and Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 71,343	$ 69,778
Accumulated depreciation and amortization	(45,684)	(44,173)
Premises and equipment, net	25,659	25,605
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	10,660	8,905
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	26,179	24,140
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 27,886	$ 30,115

Premises and Equipment, Net - N

Premises and Equipment, Net - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 3,600,000	$ 3,000,000	$ 3,200,000
Sales of premises and equipment	0	$ 0	$ 0
Leasehold improvements
Property, Plant and Equipment [Line Items]
Impairment on finite-lived intangible assets	$ 470,000

Deposits - Deposit Account Bala

Deposits - Deposit Account Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amount
Negotiable orders of withdrawal and interest-bearing deposits	$ 573,927	$ 458,012
Non-interest bearing checking	387,409	395,375
Total transaction	961,336	853,387
Money market	651,159	741,939
Savings	747,186	594,290
Total savings	1,398,345	1,336,229
Under $100,000	563,303	599,245
$100,000 or more	485,249	497,651
Total certificates of deposit	1,048,552	1,096,896
Total deposits	$ 3,408,233	$ 3,286,512
Weighted Average Rate
Negotiable orders of withdrawal and interest-bearing deposits	0.87%	0.68%
Total transaction	0.52%	0.36%
Money market	1.18%	1.12%
Savings	1.02%	0.90%
Total savings	1.09%	1.02%
Under $100,000	1.86%	1.91%
$100,000 or more	1.98%	2.01%
Total certificates of deposit	1.92%	1.96%
Total deposits	1.18%	1.16%

Deposits - Narrative (Details)

Deposits - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Certificates of Deposit
Time Deposits [Line Items]
Brokered deposits	$ 259	$ 275.4

Deposits - Maturities of Certif

Deposits - Maturities of Certificates of Deposit (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Banking and Thrift [Abstract]
2020	$ 908,744
2021	46,856
2022	49,075
2023	35,008
2024	8,869
Total certificates of deposit	$ 1,048,552	$ 1,096,896

Deposits - Interest Expense on

Deposits - Interest Expense on Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Transaction	$ 4,623	$ 2,175	$ 1,429
Savings	15,850	8,878	6,804
Certificates of deposit	20,855	16,688	8,153
Total interest expense on deposits	$ 41,328	$ 27,741	$ 16,386

Borrowings - Summary Of Borrowi

Borrowings - Summary Of Borrowings (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Repurchase agreements	$ 75,000,000	$ 0
Other borrowings:
FHLB advances	776,000,000	403,502,000
Floating rate advances	6,004,000	5,345,000
Obligations under capital leases		44,000
Total long term debt	$ 857,004,000	$ 408,891,000

Borrowings - Contractual Maturi

Borrowings - Contractual Maturities Repurchase Agreements And FHLB Advances (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Long Term Debt Maturities Repayments Of Principal [Line Items]
Total long term debt	$ 857,004	$ 408,891
FHLB Advances
Long Term Debt Maturities Repayments Of Principal [Line Items]
2019	411,000
2020	145,000
2021	95,000
2022	87,500
2023	25,000
Thereafter	12,500
Total long term debt	776,000
Repurchase agreements
Long Term Debt Maturities Repayments Of Principal [Line Items]
2019	0
2020	25,000
2021	25,000
2022	0
2023	25,000
Total long term debt	$ 75,000

Borrowings - Summary of FHLB an

Borrowings - Summary of FHLB and Repurchase Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
FHLB Advances
Debt Instrument [Line Items]
Average balance during year	$ 518,372	$ 448,012
Maximum outstanding at any month end	$ 776,000	$ 475,582
Weighted average interest rate at end of year	2.04%	1.95%
Weighted average interest rate during year	2.08%	1.82%
Repurchase Agreements
Debt Instrument [Line Items]
Average balance during year	$ 45,342	$ 0
Maximum outstanding at any month end	$ 75,000	$ 0
Weighted average interest rate at end of year	2.30%	0.00%
Weighted average interest rate during year	2.35%	0.00%

Borrowings - Narrative (Details

Borrowings - Narrative (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Repurchase agreements	$ 75,000,000	$ 0
FHLB advances	1,430,000,000
Unencumbered securities	284,800,000
Multifamily loans held as collateral	$ 1,100,000,000
Repurchase agreements | Mortgage-backed securities
Debt Instrument [Line Items]
Mortgage-backed securities amortized cost		78,900,000
Mortgage-backed securities held for sale fair value		$ 78,300,000

Borrowings - Summary Of Interes

Borrowings - Summary Of Interest Expense On Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest Expense [Line Items]
Interest expense	$ 12,030	$ 8,309	$ 7,590
Obligations under capital leases
Interest Expense [Line Items]
Interest expense	0	7	30
Repurchase Agreements
Interest Expense [Line Items]
Interest expense	1,065	7	137
FHLB advances
Interest Expense [Line Items]
Interest expense	10,795	8,172	7,390
Floating rate advances
Interest Expense [Line Items]
Interest expense	$ 170	$ 123	$ 33

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal tax expense (benefit):
Current									$ 8,543	$ 8,540	$ 10,113
Deferred									376	(742)	14,290
Federal tax expense (benefit)									8,919	7,798	24,403
State and local tax expense (benefit):
Current									4,067	1,985	1,672
Deferred									(199)	(151)	903
State and local tax expense (benefit)									3,868	1,834	2,575
Income tax expense	$ 3,052	$ 4,845	$ 2,280	$ 2,610	$ 2,314	$ 3,081	$ 1,893	$ 2,344	$ 12,787	$ 9,632	$ 26,978

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax expense at statutory rate									$ 11,135	$ 10,439	$ 18,111
Applicable statutory federal income tax rate									21.00%	21.00%	35.00%
Increase (decrease) in taxes resulting from:
State tax, net of federal income tax									$ 3,056	$ 1,448	$ 1,674
Impact of 2017 federal tax reform									0	0	10,453
Bank owned life insurance									(1,475)	(778)	(1,885)
ESOP fair market value adjustment									187	196	404
Incentive stock options									81	146	247
Uncertain tax position									0	0	132
Excess tax benefits from employee share based payments									(110)	(1,939)	(2,309)
Other, net									(87)	120	151
Income tax expense	$ 3,052	$ 4,845	$ 2,280	$ 2,610	$ 2,314	$ 3,081	$ 1,893	$ 2,344	$ 12,787	$ 9,632	$ 26,978

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Re-measurement of our net deferred tax asset	$ 10,500
State tax, net of federal income tax	3,056	$ 1,448	$ 1,674
Current state and local tax expense (benefit)	4,067	1,985	$ 1,672
Deferred tax assets, gross	24,027	27,655
Net deferred tax asset	19,748	25,325
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
New Jersey Division of Taxation
Operating Loss Carryforwards [Line Items]
State tax, net of federal income tax	889
Current state and local tax expense (benefit)	1,100
Deferred tax assets, gross	$ 239

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for loan losses	$ 7,985	$ 7,317
Capitalized leases	0	13
Deferred compensation	3,498	3,426
Accrued salaries	738	737
Postretirement benefits	376	375
Equity awards	2,164	3,045
Unrealized actuarial losses on post-retirement benefits	(21)	18
Straight-line rent	1,277	1,051
Asset retirement obligation	70	67
Reserve for accrued interest receivable	578	602
Reserve for loan commitments	216	146
Employee Stock Ownership Plan	615	551
Other	244	261
Depreciation	2,414	2,383
Fair value adjustments of acquired loans	3,713	3,934
Fair value adjustments of pension benefit obligations	160	154
Unrealized losses on debt securities available-for-sale	0	3,575
Total gross deferred tax assets	24,027	27,655
Deferred tax liabilities:
Unrealized gains on debt securities available for sale	1,786	0
Fair value adjustments of acquired securities	20	28
Fair value adjustments of deposit liabilities	219	285
Deferred loan fees	2,224	1,984
Other	30	33
Total gross deferred tax liabilities	4,279	2,330
Net deferred tax asset	$ 19,748	$ 25,325

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Uncertain Tax Position (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 530	$ 482	$ 459
Settlements based on tax positions related to prior years	(530)	(238)	(109)
Additions based on tax positions related to prior years	190	286	132
Ending balance	$ 530	$ 482	$ 459	$ 190

Retirement Benefits - Narrative

Retirement Benefits - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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	$ 426,000	$ 394,000	$ 387,000
ESOP compensation expense	1,900,000	2,000,000	2,200,000
Estimated loss that will be amortized from accumulated other comprehensive income (loss) into net periodic cost	835
Prior service cost that will be amortized from accumulated other comprehensive income (loss) into net periodic cost	(19,000)
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	$ 103,000	120,000	112,000
Benefits expected to be paid under the postretirement health benefits plan in 2020	108,000
Benefits expected to be paid under the postretirement health benefits plan in 2021	108,000
Benefits expected to be paid under the postretirement health benefits plan in 2022	107,000
Benefits expected to be paid under the postretirement health benefits plan in 2023	88,000
Benefits expected to be paid under the postretirement health benefits plan in 2024	85,000
Benefits expected to be paid under the postretirement health benefits plan in 2025 through 2029	359,000
Supplemental Employee Retirement Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	14,700,000	12,700,000
Net postretirement benefit cost included in compensation and employee benefits	$ 2,000,000	(879,000)	1,100,000
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%
Northfield Bank ESOP
Defined Benefit Plan Disclosure [Line Items]
Employee stock ownership plan, shares authorized and purchased	2,463,884
Initial public offering price (dollars per share)	$ 7.13
Outstanding loan balance	$ 10,100,000	$ 10,800,000
Shares released and allocated to participants (in shares)	100,841	101,514
Second ESOP
Defined Benefit Plan Disclosure [Line Items]
Employee stock ownership plan, shares authorized and purchased	1,422,357
Initial public offering price (dollars per share)	$ 10
Outstanding loan balance	$ 11,800,000	$ 12,200,000
Shares released and allocated to participants (in shares)	53,320	52,523
Supplemental ESOP
Defined Benefit Plan Disclosure [Line Items]
Company contribution to SESOP plan	$ 41,000	$ 76,000	$ 84,000

Retirement Benefits - Funded St

Retirement Benefits - Funded Status and Components of Post Retirement Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid	$ (103)	$ (120)	$ (112)
Other Pension Plans, Defined Benefit
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Accumulated postretirement benefit obligation beginning of year	1,359	1,645	1,697
Service cost	9	11	11
Interest cost	52	52	57
Actuarial (gain) loss	(76)	(229)	(8)
Benefits paid	(103)	(120)	(112)
Accumulated postretirement benefit obligation end of year	1,241	1,359	1,645
Accrued liability (included in accrued expenses and other liabilities)	$ 1,241	$ 1,359	$ 1,645

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, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Net loss	$ 132	$ 20
Prior service credit	(191)	0
(Gain) loss recognized in accumulated other comprehensive income (loss)	$ (59)	$ 20

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, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 9	$ 11	$ 11
Interest cost	52	52	57
Amortization of unrecognized loss	2	25	28
Net postretirement benefit cost included in compensation and employee benefits	$ 63	$ 88	$ 96

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, 2019	Dec. 31, 2018	Dec. 31, 2017
Assumptions used to determine benefit obligation at period end:
Discount rate	2.75%	4.00%	3.25%
Rate of increase in compensation	4.00%	4.00%	4.00%
Assumptions used to determine net periodic benefit cost for the year:
Discount rate	4.00%	3.25%	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, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Aggregate of service and interest components of net periodic cost (benefit), one percentage point increase	$ 4	$ 4	$ 4
Aggregate of service and interest components of net periodic cost (benefit), one percentage point decrease	(4)	(3)	$ (4)
Effect on accumulated postretirement benefit obligation, one percentage point increase	104	109
Effect on accumulated postretirement benefit obligation, one percentage point decrease	$ (90)	$ (94)

Equity Incentive Plan - Narrati

Equity Incentive Plan - Narrative (Details) $ in Thousands	Aug. 27, 2018shares	Nov. 01, 2017shares	Sep. 19, 2017shares	Aug. 01, 2017shares	Dec. 31, 2019USD ($)shares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)shares	May 22, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)						0	0
Allocated stock-based compensation expense | $						$ 3,200	$ 5,400	$ 6,200
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	4,311,796
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	4,978,249
Vesting period (years)						5 years
Expirations in period (in shares)							348,373
2019 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option and non-option shares granted (in shares)					0
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected future stock-based compensation expense | $					$ 474	$ 474
Average period of expected future stock option expense						9 months 14 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	1,231,941
Shares available for issuance under equity incentive plan (in shares)							0
Shares granted (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 | 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	1,422,357
Shares available for issuance under equity incentive plan (in shares)							142,154
Shares granted (in shares)	11,622
Vesting period (years)	2 years
Beginning of vesting period (years)	6 months
Non-option equity expirations (in shares)							142,154
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected future stock-based compensation expense | $					$ 255	$ 255
Average period of expected future stock option expense						9 months 7 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	3,079,855
Shares available for issuance under equity incentive plan (in shares)					0	0
Stock options granted (in shares)		40,000,000	12,500,000	45,744,000
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 | 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	3,555,892
Shares available for issuance under equity incentive plan (in shares)							348,373
Beginning of vesting period (years)						1 year
Stock option expiration period (years)						10 years
Employee Stock Option and Stock Appreciation Rights (SARs) | 2019 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)									6,000,000
Shares authorized under equity incentive plan, issued in form of restricted stock, reduction (in shares)									4.5
Restricted Stock And Restricted Stock Units (RSUs) | 2019 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under equity incentive plan (in shares)									1,333,333

Equity Incentive Plan - Valuati

Equity Incentive Plan - Valuation Assumptions (Details) - shares	Nov. 01, 2017	Sep. 19, 2017	Aug. 01, 2017	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)				0	0
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
Risk-free rate of return	2.06%	1.89%	1.86%
Volatility (percent)	29.22%	30.06%	29.46%
Dividend yield (percent)	2.37%	1.98%	1.91%
Expected life	5 years 9 months	5 years 9 months	5 years 9 months

Equity Incentive Plan - Stock O

Equity Incentive Plan - Stock Options Outstanding (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Stock Options
Outstanding (in shares) - Beginning Balance	3,251,595	4,620,687
Forfeited (in shares)	(15,000)	(29,378)
Exercised (in shares)	(1,009,402)	(1,339,714)
Outstanding (in shares) - Ending Balance	2,227,193	3,251,595	4,620,687
Exercisable (in shares)	2,046,272
Weighted Average Grant Date Fair Value
Outstanding (dollars per share) - Beginning Balance	$ 3.93	$ 3.51
Forfeited (dollars per share)	4.07	3.36
Exercised (dollars per share)	3.75	2.49
Outstanding (dollars per share) - Ending Balance	4.01	3.93	$ 3.51
Exercisable (dollars per share)	3.99
Weighted Average Exercise Price
Outstanding (dollars per share) - Beginning Balance	13.51	11.82
Forfeited (dollars per share)	14.76	11.51
Exercised (dollars per share)	12.54	7.75
Outstanding (dollars per share) - Ending Balance	13.93	$ 13.51	$ 11.82
Exercisable (dollars per share)	$ 13.83
Weighted Average Contractual Life (years)
Outstanding, weighted average contractual life (years)	4 years 11 months 15 days	5 years 7 months 13 days	5 years 2 months 1 day
Exercisable, weighted average contractual life (years)	4 years 10 months 28 days

Equity Incentive Plan - Status

Equity Incentive Plan - Status of the Company's Restricted Share Awards (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Number of Shares Awarded
Non-vested (in shares) - Beginning Balance	328,962	585,895
Granted (in shares)		15,000
Vested (in shares)	(249,860)	(266,973)
Forfeited (in shares)	(8,000)	(4,960)
Non-vested (in shares) - Ending Balance	71,102	328,962
Weighted Average Grant Date Fair Value
Non-vested (dollars per share) - Beginning Balance	$ 14.31	$ 14.05
Granted (dollars per share)		16.48
Vested (dollars per share)	13.99	13.86
Forfeited (dollars per share)	14.76	14.18
Non-vested (dollars per share) - Ending Balance	$ 15.36	$ 14.31

Commitments and Contingencies -

Commitments and Contingencies - Commitment and Contingent Liabilities Not Reflected in Consolidated Financial Statements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Commitments to extend credit
Commitments and contingent liabilities	$ 125,630	$ 39,326
Unused lines of credit
Commitments and contingent liabilities	143,164	136,586
Standby letters of credit
Commitments and contingent liabilities	$ 6,713	$ 5,352

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Guarantees extend term period (years)	1 year
Allowance for estimated losses on commitments	$ 756	$ 523
Agreements term (years)	3 years

Regulatory Requirements - Narra

Regulatory Requirements - Narrative (Details)	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2016
Regulatory Requirements [Abstract]
Common equity Tier 1 capital (to risk-weighted assets), for capital adequacy purposes ratio	4.50%	4.50%
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes ratio	6.00%	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	2.50%
Capital conservation buffer			0.625%

Regulatory Requirements - Regul

Regulatory Requirements - Regulatory Capital Amounts And Ratios Compared To Regulatory Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Capital (to risk-weighted assets), amount	$ 651,974	$ 636,141
Common Equity Tier 1 Capital (to risk-weighted assets), ratio	16.35%	17.17%
Common Equity Tier 1 Capital (to risk-weighted assets), for capital adequacy purposes amount	$ 179,439	$ 166,717
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	$ 259,189	$ 240,814
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	$ 651,974	$ 636,141
Tier 1 capital (core) (to adjusted total assets), ratio	13.37%	14.82%
Tier 1 capital (core) (to adjusted total assets), for capital adequacy purposes amount	$ 195,018	$ 171,724
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	$ 243,772	$ 214,656
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	$ 651,974	$ 636,141
Tier 1 capital (to risk-weighted assets), ratio	16.35%	17.17%
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes amount	$ 239,251	$ 222,290
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	$ 319,002	$ 296,386
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	$ 681,467	$ 664,190
Total capital (to risk-weighted assets), ratio	17.09%	17.93%
Total capital (to risk-weighted assets), for capital adequacy purposes amount	$ 319,002	$ 296,386
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	$ 398,752	$ 370,483
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	$ 598,462	$ 592,815
Common Equity Tier 1 Capital (to risk-weighted assets), ratio	14.99%	16.00%
Common Equity Tier 1 Capital (to risk-weighted assets), for capital adequacy purposes amount	$ 179,626	$ 166,742
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	$ 259,459	$ 240,850
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	$ 598,462	$ 592,815
Tier 1 capital (core) (to adjusted total assets), ratio	12.28%	13.81%
Tier 1 capital (core) (to adjusted total assets), for capital adequacy purposes amount	$ 194,954	$ 171,663
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	$ 243,692	$ 214,579
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	$ 598,462	$ 592,815
Tier 1 capital (to risk-weighted assets), ratio	14.99%	16.00%
Tier 1 capital (to risk-weighted assets), for capital adequacy purposes amount	$ 239,501	$ 222,323
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	$ 319,334	$ 296,430
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	$ 627,955	$ 620,863
Total capital (to risk-weighted assets), ratio	15.73%	16.76%
Total capital (to risk-weighted assets), for capital adequacy purposes amount	$ 319,334	$ 296,430
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	$ 399,168	$ 370,538
Total capital (to risk-weighted assets), for well capitalized under prompt corrective action provisions ratio	10.00%	10.00%

Fair Value Measurement - Fair V

Fair Value Measurement - Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	$ 1,138,352	$ 808,031
Impaired loans	4,942	5,697
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	1,138,352	808,031
Trading securities	11,222	8,968
Equity securities	250	237
Total	1,149,824	817,236
Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Trading securities	11,222	8,968
Equity securities	250	237
Total	11,472	9,205
Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	1,138,352	808,031
Trading securities	0	0
Equity securities	0	0
Total	1,138,352	808,031
Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Trading securities	0	0
Equity securities	0	0
Total	0	0
Recurring Basis | Mortgage-backed securities:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	973,127	565,009
Recurring Basis | Mortgage-backed securities: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Mortgage-backed securities: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	973,127	565,009
Recurring Basis | Mortgage-backed securities: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Mortgage-backed securities, Pass-through certificates, GSE
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	329,407	314,788
Recurring Basis | Mortgage-backed securities, Pass-through certificates, GSE | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Mortgage-backed securities, Pass-through certificates, GSE | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	329,407	314,788
Recurring Basis | Mortgage-backed securities, Pass-through certificates, GSE | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Mortgage-backed securities, REMICs, GSE
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	643,667	250,163
Recurring Basis | Mortgage-backed securities, REMICs, GSE | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0
Recurring Basis | Mortgage-backed securities, REMICs, GSE | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	643,667	250,163
Recurring Basis | Mortgage-backed securities, REMICs, GSE | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Mortgage-backed securities, REMICs, Non-GSE
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	53	58
Recurring Basis | Mortgage-backed securities, REMICs, Non-GSE | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Mortgage-backed securities, REMICs, Non-GSE | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	53	58
Recurring Basis | Mortgage-backed securities, REMICs, Non-GSE | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	299	273
Recurring Basis | Municipal bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Municipal bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	299	273
Recurring Basis | Municipal bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale		0
Recurring Basis | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	164,926	242,749
Recurring Basis | Corporate bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Corporate bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	164,926	242,749
Recurring Basis | Corporate bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Other debt obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	165,225	243,022
Recurring Basis | Other debt obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Recurring Basis | Other debt obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	165,225	243,022
Recurring Basis | Other debt obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available-for-sale	0	0
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	4,942	5,697
Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	4,942	5,697
Real Estate | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,927	5,679
Real Estate | Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Real Estate | Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Real Estate | Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,927	5,679
Real Estate | Nonrecurring | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,871	4,847
Real Estate | Nonrecurring | Commercial real estate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Real Estate | Nonrecurring | Commercial real estate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Real Estate | Nonrecurring | Commercial real estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,871	4,847
Real Estate | Nonrecurring | One-to-four family residential mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		765
Real Estate | 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
Real Estate | 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
Real Estate | Nonrecurring | One-to-four family residential mortgage | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans		765
Real Estate | Nonrecurring | Multifamily
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	26	39
Real Estate | Nonrecurring | Multifamily | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Real Estate | Nonrecurring | Multifamily | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Real Estate | Nonrecurring | Multifamily | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	26	39
Real Estate | Nonrecurring | Home equity and lines of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	30	28
Real Estate | 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
Real Estate | 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
Real Estate | Nonrecurring | Home equity and lines of credit | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	30	28
Commercial and Industrial | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	15	18
Commercial and Industrial | Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Commercial and Industrial | Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Commercial and Industrial | Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 15	$ 18

Fair Value Measurement - Qualit

Fair Value Measurement - Qualitative Information for Level 3 Assets Measured at Fair Value on a Non-Recurring Basis (Details) $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans	$ 4,942	$ 5,697
Appraisals | Discount rate | Discount for costs to sell
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, measurement input	0.070	0.070
Appraisals | Discount rate | Discount for quick sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, measurement input	0.100	0.100
Appraisals | Discount rate | Interest rates | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, measurement input		0.0413
Appraisals | Discount rate | Interest rates | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, measurement input		0.0625
Discounted cash flows | Discount rate | Interest rates | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, measurement input	0.0413
Discounted cash flows | Discount rate | Interest rates | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, measurement input	0.0625

Fair Value Measurement - Narrat

Fair Value Measurement - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Impaired loans held-for-investment and held-for-sale with outstanding principal balances	$ 7,000	$ 10,200
Estimated fair value of impaired loans held-for-investment and held-for-sale	4,900	5,700
Decrease in reserve for impaired loans	116	56
Net impairment charge-offs	$ 1,200	$ 1,300

Fair Value Measurement - Estima

Fair Value Measurement - Estimated Fair Values of The Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financial assets:
Debt securities available-for-sale	$ 1,138,352	$ 808,031
Debt securities held-to-maturity	8,886	9,249
Financial liabilities:
Investments measured at net asset value	3,100	1,000
Carrying Value
Financial assets:
Cash and cash equivalents	147,818	77,762
Trading securities	11,222	8,968
Debt securities available-for-sale	1,138,352	808,031
Debt securities held-to-maturity	8,762	9,505
Equity securities	250	237
FHLB of New York stock, at cost	39,575	22,517
Net loans held-for-investment	3,408,378	3,217,673
Financial liabilities:
Deposits	3,408,233	3,286,512
Repurchase agreements, FHLB advances and other borrowings	857,004	408,891
Advance payments by borrowers	44,069	18,007
Estimated Fair Value
Financial assets:
Cash and cash equivalents	147,818	77,762
Trading securities	11,222	8,968
Debt securities available-for-sale	1,138,352	808,031
Debt securities held-to-maturity	8,886	9,249
Equity securities	250	237
FHLB of New York stock, at cost	39,575	22,517
Net loans held-for-investment	3,482,804	3,236,136
Financial liabilities:
Deposits	3,412,414	3,291,085
Repurchase agreements, FHLB advances and other borrowings	862,980	403,476
Advance payments by borrowers	44,069	18,007
Estimated Fair Value | Level 1
Financial assets:
Cash and cash equivalents	147,818	77,762
Trading securities	11,222	8,968
Debt securities available-for-sale	0	0
Debt securities held-to-maturity	0	0
Equity securities	250	237
FHLB of New York stock, at cost	0	0
Net loans held-for-investment	0	0
Financial liabilities:
Deposits	0	0
Repurchase agreements, FHLB advances 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
Debt securities available-for-sale	1,138,352	808,031
Debt securities held-to-maturity	8,886	9,249
Equity securities	0	0
FHLB of New York stock, at cost	39,575	22,517
Net loans held-for-investment	0	0
Financial liabilities:
Deposits	3,412,414	3,291,085
Repurchase agreements, FHLB advances and other borrowings	862,980	403,476
Advance payments by borrowers	44,069	18,007
Estimated Fair Value | Level 3
Financial assets:
Cash and cash equivalents	0	0
Trading securities	0	0
Debt securities available-for-sale	0	0
Debt securities held-to-maturity	0	0
Equity securities	0	0
FHLB of New York stock, at cost	0	0
Net loans held-for-investment	3,482,804	3,236,136
Financial liabilities:
Deposits	0	0
Repurchase agreements, FHLB advances 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	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income available to common stockholders	$ 10,121	$ 13,139	$ 8,204	$ 8,771	$ 9,946	$ 9,076	$ 10,612	$ 10,445	$ 40,235	$ 40,079	$ 24,768
Weighted average shares outstanding-basic (in shares)									46,783,442	46,319,760	45,325,445
Effect of non-vested restricted stock and stock options outstanding (in shares)									380,362	787,673	1,550,285
Weighted average shares outstanding-diluted (in shares)									47,163,804	47,107,433	46,875,730
Earnings per share-basic (dollars per share)	$ 0.22	$ 0.28	$ 0.18	$ 0.19	$ 0.21	$ 0.19	$ 0.23	$ 0.23	$ 0.86	$ 0.87	$ 0.55
Earnings per share-diluted (dollars per share)	$ 0.21	$ 0.28	$ 0.17	$ 0.19	$ 0.21	$ 0.19	$ 0.23	$ 0.22	$ 0.85	$ 0.85	$ 0.53
Anti-dilutive shares (in shares)									546,120	765,792	334,927

Stock Repurchase Program (Detai

Stock Repurchase Program (Details) $ in Millions	Apr. 24, 2019USD ($)
Equity [Abstract]
Stock repurchase program, authorized amount	$ 37.2

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Fees and service charges for customer services									$ 4,881	$ 4,877	$ 4,702
Income on bank owned life insurance									7,023	3,705	5,386
Gains (losses) on securities, net									1,988	(879)	1,114
Gains on available-for-sale debt securities, net									514	178	169
Other									402	246	271
Total non-interest income	$ 4,195	$ 4,733	$ 2,566	$ 3,314	$ 640	$ 2,637	$ 2,445	$ 2,405	14,808	8,127	11,642
Service charges
Disaggregation of Revenue [Line Items]
Fees and service charges for customer services									3,309	3,356	3,320
ATM and card interchange fees
Disaggregation of Revenue [Line Items]
Fees and service charges for customer services									1,310	1,216	1,150
Investment fees
Disaggregation of Revenue [Line Items]
Fees and service charges for customer services									$ 262	$ 305	$ 232

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Lessee, Lease, Description [Line Items]
Operating lease, rent expense	$ 6,800
Operating lease, rent expense		$ 5,700	$ 5,300
Operating lease right-of-use assets	39,504
Operating lease liabilities	44,069
Operating lease, accelerated rent expense	$ 579
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract	9 months
Lessee, operating lease, renewal term	5 years
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract	35 years 6 months
Lessee, operating lease, renewal term	10 years

Leases - Supplemental Lease Inf

Leases - Supplemental Lease Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating lease cost	$ 6,698
Variable lease cost	2,813
Net lease cost	9,511
Cash paid for amounts included in measurement of operating lease liabilities	5,901
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 1,013
Weighted average remaining lease term (in years) at December 31, 2019	12 years 9 months 7 days
Weighted average discount rate at December 31, 2019	3.62%

Leases - Lease Payment Obligati

Leases - Lease Payment Obligations (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
2020	$ 6,160
2021	5,730
2022	5,068
2023	4,975
2024	4,629
Thereafter	30,668
Total lease payments	57,230
Less: imputed interest	(13,161)
Present value of lease liabilities	$ 44,069

Derivatives (Details)

Derivatives (Details) - Interest Rate Swap	12 Months Ended
	Dec. 31, 2019USD ($)instrument	Dec. 31, 2018USD ($)
Derivative [Line Items]
Number of derivative instruments | instrument	1
Derivative notional amount	$ 12,000,000
Derivative assets (liabilities), fair value, net	79,000	$ 0
Interest and fee income, derivative	$ 147,000

Parent-only Financial Informa_3

Parent-only Financial Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS:
Interest-earning deposits in other financial institutions	$ 132,409	$ 62,615
Other assets	26,212	31,586
Total assets	5,055,302	4,408,432
LIABILITIES AND STOCKHOLDERS’ EQUITY:
Total liabilities	4,359,449	3,741,993
Total stockholders' equity	695,853	666,439	$ 638,877	$ 621,196
Total liabilities and stockholders' equity	5,055,302	4,408,432
Parent Company
ASSETS:
Cash in Northfield Bank	32,828	21,884
Interest-earning deposits in other financial institutions	280	21
Investment in Northfield Bank	642,341	623,113
ESOP loan receivable	21,897	22,962
Other assets	132	120
Total assets	697,478	668,100
LIABILITIES AND STOCKHOLDERS’ EQUITY:
Total liabilities	1,625	1,661
Total stockholders' equity	695,853	666,439
Total liabilities and stockholders' equity	$ 697,478	$ 668,100

Parent-only Financial Informa_4

Parent-only Financial Information - Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income tax expense	$ 3,052	$ 4,845	$ 2,280	$ 2,610	$ 2,314	$ 3,081	$ 1,893	$ 2,344	$ 12,787	$ 9,632	$ 26,978
Net income	$ 10,121	$ 13,139	$ 8,204	$ 8,771	$ 9,946	$ 9,076	$ 10,612	$ 10,445	40,235	40,079	24,768
Other comprehensive income (loss), net of tax									13,846	(3,696)	(227)
Comprehensive income									54,081	36,383	24,541
Parent Company
Interest on ESOP loan									1,263	1,081	939
Interest income on deposits in other financial institutions									229	38	31
Gains (losses) gains on securities, net									10	(6)	5
Undistributed earnings of Northfield Bank									40,012	40,092	24,887
Total income									41,514	41,205	25,862
Other expenses									863	890	872
Income tax expense									416	236	222
Total expense									1,279	1,126	1,094
Net income									40,235	40,079	24,768
Other comprehensive income (loss), net of tax									13,846	(3,696)	(227)
Comprehensive income									$ 54,081	$ 36,383	$ 24,541

Parent-only Financial Informa_5

Parent-only Financial Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 10,121	$ 13,139	$ 8,204	$ 8,771	$ 9,946	$ 9,076	$ 10,612	$ 10,445	$ 40,235	$ 40,079	$ 24,768
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
(Increase) decrease in other assets									2,679	3,563	(3,689)
Net cash (used in) provided by operating activities									51,152	52,789	43,624
Cash flows from investing activities:
Net cash provided by investing activities									(522,725)	(406,360)	(190,526)
Cash flows from financing activities:
Exercise of stock options									5,770	2,088	100
Net cash used in financing activities									541,629	373,494	108,656
Net increase (decrease) in cash and cash equivalents									70,056	19,923	(38,246)
Cash and cash equivalents at beginning of period				77,762				57,839	77,762	57,839	96,085
Cash and cash equivalents at end of period	147,818				77,762				147,818	77,762	57,839
Parent Company
Cash flows from operating activities:
Net income									40,235	40,079	24,768
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
(Increase) decrease in other assets									(1,073)	3	(2,008)
(Gains) losses on securities, net									(10)	6	(5)
(Decrease) increase in other liabilities									(36)	846	(980)
Undistributed earnings of Northfield Bank									(40,012)	(40,092)	(24,887)
Net cash (used in) provided by operating activities									(896)	842	(3,112)
Cash flows from investing activities:
Dividends from Northfield Bank									41,277	16,493	28,763
Net cash provided by investing activities									41,277	16,493	28,763
Cash flows from financing activities:
Principal payments on ESOP loan receivable									1,065	1,059	1,022
Purchase of treasury stock									(15,815)	(5)	0
Dividends paid									(20,198)	(18,673)	(15,646)
Exercise of stock options									5,770	2,088	100
Net cash used in financing activities									(29,178)	(15,531)	(14,524)
Net increase (decrease) in cash and cash equivalents									11,203	1,804	11,127
Cash and cash equivalents at beginning of period				$ 21,905				$ 20,101	21,905	20,101	8,974
Cash and cash equivalents at end of period	$ 33,108				$ 21,905				$ 33,108	$ 21,905	$ 20,101

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 42,637	$ 42,847	$ 40,193	$ 39,466	$ 38,948	$ 37,727	$ 35,935	$ 34,682	$ 165,143	$ 147,292	$ 132,869
Interest expense	14,161	14,027	13,034	12,136	10,944	9,803	8,165	7,138	53,358	36,050	23,976
Net interest income	28,476	28,820	27,159	27,330	28,004	27,924	27,770	27,544	111,785	111,242	108,893
Provision for loan losses	772	(1,300)	491	59	607	1,304	670	34	22	2,615	1,411
Net interest income after provision for loan losses	27,704	30,120	26,668	27,271	27,397	26,620	27,100	27,510	111,763	108,627	107,482
Other income	4,195	4,733	2,566	3,314	640	2,637	2,445	2,405	14,808	8,127	11,642
Other expenses	18,726	16,869	18,750	19,204	15,777	17,100	17,040	17,126	73,549	67,043	67,378
Income before income tax expense	13,173	17,984	10,484	11,381	12,260	12,157	12,505	12,789	53,022	49,711	51,746
Income tax expense	3,052	4,845	2,280	2,610	2,314	3,081	1,893	2,344	12,787	9,632	26,978
Net income	$ 10,121	$ 13,139	$ 8,204	$ 8,771	$ 9,946	$ 9,076	$ 10,612	$ 10,445	$ 40,235	$ 40,079	$ 24,768
Net income per basic common share (dollars per share)	$ 0.22	$ 0.28	$ 0.18	$ 0.19	$ 0.21	$ 0.19	$ 0.23	$ 0.23	$ 0.86	$ 0.87	$ 0.55
Net income per diluted common share (dollars per share)	$ 0.21	$ 0.28	$ 0.17	$ 0.19	$ 0.21	$ 0.19	$ 0.23	$ 0.22	$ 0.85	$ 0.85	$ 0.53

Uncategorized Items - nfbk20191

Label	Element	Value
Accounting Standards Update 2016-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 0
Accounting Standards Update 2016-09 [Member] | Additional Paid-in Capital [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(2,898,000)
Accounting Standards Update 2016-09 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 2,898,000