Blue Hills Bancorp (BHBK) 10-Q 1 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Blue Hills Bancorp, Inc.
Entity Central Index Key	1,601,545
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	true
Entity Small Business	false
Entity Ex Transition Period	true
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		26,857,844

Consolidated Balance Sheets (un

Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets
Cash and due from banks	$ 15,459	$ 16,149
Short-term investments	32,290	30,018
Total cash and cash equivalents	47,749	46,167
Equity securities, at fair value	5,270	0
Securities available for sale, at fair value	0	9,720
Securities held to maturity, at amortized cost	305,935	303,716
Federal Home Loan Bank stock, at cost	11,815	12,105
Loans held for sale	5,035	8,992
Loans, net of allowance for loan losses of $19,920 at September 30, 2018 and $20,877 at December 31, 2017	2,286,796	2,186,147
Premises and equipment, net	19,882	21,573
Other real estate owned	3,649	0
Accrued interest receivable	7,143	6,438
Goodwill	9,160	9,160
Core deposit intangible	175	557
Net deferred tax asset	6,995	6,000
Bank-owned life insurance	33,889	33,078
Other assets	39,061	24,867
Total assets	2,782,554	2,668,520
Deposits:
Non-interest bearing	240,673	219,984
Interest bearing	1,925,334	1,819,885
Total deposits	2,166,007	2,039,869
Short-term borrowings	98,000	100,000
Long-term debt	80,000	105,000
Accrued expenses and other liabilities	35,471	25,845
Total liabilities	2,379,478	2,270,714
Stockholders' Equity:
Preferred stock, zero par value, (50,000,000 shares authorized; none issued and outstanding)	0	0
Common stock, $0.01 par value, (100,000,000 shares authorized; 26,899,594 and 26,827,660 issued and outstanding at September 30, 2018 and December 31, 2017, respectively)	269	268
Additional paid-in capital	259,892	254,750
Unearned compensation-ESOP	(19,168)	(19,737)
Retained earnings	163,892	163,978
Accumulated other comprehensive loss	(1,809)	(1,453)
Total stockholders' equity	403,076	397,806
Total liabilities and stockholders' equity	$ 2,782,554	$ 2,668,520

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Loans, net of allowance for loan losses of $19,920 at September 30, 2018 and $20,877 at December 31, 2017	$ 19,920	$ 20,877
Preferred stock, par value (dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	26,899,594	26,827,660
Common stock, shares outstanding	26,899,594	26,827,660

Consolidated Statements of Net

Consolidated Statements of Net Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest and dividend income:
Interest and fees on loans	$ 24,455	$ 19,721	$ 69,345	$ 55,818
Interest on securities	1,854	1,565	5,520	5,347
Dividends	210	194	609	544
Other	92	65	232	191
Total interest and dividend income	26,611	21,545	75,706	61,900
Interest expense:
Interest on deposits	6,357	4,089	16,384	10,866
Interest on borrowings	791	502	2,517	1,791
Total interest expense	7,148	4,591	18,901	12,657
Net interest and dividend income	19,463	16,954	56,805	49,243
Provision (credit) for loan losses	(182)	242	(541)	1,417
Net interest and dividend income, after provision (credit) for loan losses	19,645	16,712	57,346	47,826
Non-interest income:
Deposit account fees	473	385	1,250	1,046
Interchange and ATM fees	471	455	1,316	1,191
Mortgage banking	974	1,146	2,747	3,105
Loss on sale of purchased home equity portfolio	0	(118)	0	(118)
Loan level derivative income	1,044	156	1,427	1,687
Net unrealized (losses) gains on equity securities	(61)	0	322	0
Gain (loss) on sales of available for sale securities, net	0	0	0	(94)
Gain on exchange of investment in Northeast Retirement Services	0	0	653	5,947
Bank-owned life insurance income	279	268	811	786
Gain on sale of premises and equipment	0	0	271	0
Miscellaneous	675	534	2,588	602
Total non-interest income	3,855	2,826	11,385	14,152
Non-interest expense:
Salaries and employee benefits	8,874	7,979	25,520	23,206
Occupancy and equipment	2,071	2,024	6,204	6,169
Data processing	1,062	1,016	3,160	3,082
Professional fees	302	340	1,205	1,735
Advertising	509	563	1,312	1,419
FDIC deposit insurance	221	226	684	661
Directors’ fees	383	382	1,154	1,184
Amortization of core deposit intangible	103	199	381	668
Merger expenses	1,321	0	1,321	0
Other general and administrative	677	626	2,144	1,997
Total non-interest expense	15,523	13,355	43,085	40,121
Income before income taxes	7,977	6,183	25,646	21,857
Provision for income taxes	2,188	2,342	6,817	6,661
Net income	$ 5,789	$ 3,841	$ 18,829	$ 15,196
Earnings per common share:
Basic (dollars per share)	$ 0.24	$ 0.16	$ 0.78	$ 0.63
Diluted (dollars per share)	$ 0.23	$ 0.16	$ 0.75	$ 0.62
Weighted average shares outstanding:
Basic (shares)	24,256,902	23,973,116	24,220,055	23,945,885
Diluted (shares)	25,242,737	24,510,092	25,021,158	24,377,662

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 5,789	$ 3,841	$ 18,829	$ 15,196
Securities available for sale:
Change in unrealized holding gains		0	(494)	0	3,499
Reclassification adjustment for net losses realized in net income	[1]	0	0	0	94
Net change in unrealized gains		0	(494)	0	3,593
Tax effect		0	197	0	(1,230)
Net-of-tax amount		0	(297)	0	2,363
Securities held to maturity:
Reclassification adjustment for amortization of amounts previously recorded upon transfer from available-for-sale	[2]	(23)	(22)	(63)	(67)
Tax effect		6	8	17	13
Net-of-tax amount		(17)	(14)	(46)	(54)
Defined benefit pension plan:
Reclassification adjustment for net actuarial loss recognized in net periodic benefit cost	[3]	66	89	199	267
Tax effect		(19)	(31)	(57)	(121)
Net-of-tax amount		47	58	142	146
Other comprehensive income (loss)		30	(253)	96	2,455
Comprehensive income		$ 5,819	$ 3,588	$ 18,925	$ 17,651
[1]	Amounts are included in loss on sales of available for sale securities, net, in the consolidated statements of net income. Income tax benefit associated with the reclassification adjustment for the nine months ended September 30, 2017 was $32,000.
[2]	Amounts are included in interest income on securities in the consolidated statements of net income.
[3]	Amounts are included in salaries and employee benefits expense in the consolidated statements of net income.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Statement of Comprehensive Income [Abstract]
Reclassification adjustment for net losses realized in net income, tax	$ (32)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (unaudited) - USD ($)	Total	Common Stock	Additional paid-in capital	Unearned compensation- ESOP	Retained earnings	Accumulated other comprehensive (loss) income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle ASU 2016-01 (Note 2)			$ 27,000		$ (27,000)
Beginning balance at Dec. 31, 2016		$ 268,000	249,308,000	$ (20,496,000)	161,896,000	$ (4,069,000)
Beginning balance (shares) at Dec. 31, 2016		26,759,953
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	$ 17,651,000				15,196,000	2,455,000
ESOP shares committed to be released	1,041,000		472,000	569,000
Common stock dividends declared ($0.08 and $0.45 per common share for the nine months ended September 30, 2016 and 2017, respectively)	(10,783,000)				(10,783,000)
Restricted stock awards granted (shares)		184,695
Restricted stock awards granted	0
Restricted stock awards forfeited (shares)		(85,317)
Restricted stock awards forfeited	0
Share-based compensation expense	4,108,000		4,108,000
Share redemption for tax withholdings for restricted stock vesting (shares)		(5,903)
Share redemption for tax withholdings for restricted stock vesting			(107,000)
Proceeds from exercise of options (shares)		15,660
Proceeds from exercise of options, net	217,000		217,000
Ending balance at Sep. 30, 2017	399,034,000	$ 268,000	254,025,000	(19,927,000)	166,282,000	(1,614,000)
Ending balance (shares) at Sep. 30, 2017		26,869,088
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle ASU 2016-01 (Note 2) | ASU 2016-01					173,000	(173,000)
Cumulative effect of change in accounting principle ASU 2016-01 (Note 2) | ASU 2018-02					279,000	(279,000)
Beginning balance at Dec. 31, 2017	397,806,000	$ 268,000	254,750,000	(19,737,000)	163,978,000	(1,453,000)
Beginning balance (shares) at Dec. 31, 2017		26,827,660
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	18,925,000				18,829,000	96,000
ESOP shares committed to be released	1,209,000		640,000	569,000
Common stock dividends declared ($0.08 and $0.45 per common share for the nine months ended September 30, 2016 and 2017, respectively)	(19,367,000)				(19,367,000)
Restricted stock awards granted (shares)		59,300
Restricted stock awards forfeited (shares)		(24,890)
Share-based compensation expense	4,129,000		4,129,000
Share redemption for tax withholdings for restricted stock vesting (shares)		(16,860)
Share redemption for tax withholdings for restricted stock vesting	$ (345,000)		(345,000)
Proceeds from exercise of options (shares)	60,500	54,384
Proceeds from exercise of options, net	$ 719,000	$ 1,000	718,000
Ending balance at Sep. 30, 2018	$ 403,076,000	$ 269,000	$ 259,892,000	$ (19,168,000)	$ 163,892,000	$ (1,809,000)
Ending balance (shares) at Sep. 30, 2018		26,899,594

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]
Common stock paid (dollars per share)	$ 0.80	$ 0.45

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 18,829	$ 15,196
Adjustments to reconcile net income to net cash provided by operating activities:
Provision (credit) for loan losses	(541)	1,417
Net amortization of securities	716	1,363
Loss on sales of available for sale securities, net	0	94
Unrealized gains on equity securities, net	(322)	0
Net change in loans held for sale	3,957	(9,507)
Losses (gains) on sales of portfolio loans, net	41	(58)
Loss on sale of purchased home equity portfolio	0	118
Net amortization of net deferred loan origination costs and discounts	(507)	105
Depreciation and amortization of premises and equipment	1,532	1,596
Amortization of core deposit intangible	381	668
Bank-owned life insurance income	(811)	(786)
ESOP expense	1,209	1,041
Deferred income tax benefit	(1,035)	(487)
Share-based compensation expense	4,129	4,108
Gain on exchange of investment in Northeast Retirement Services	(653)	(5,947)
Gain on sale of premises and equipment	(271)	0
Net change in:
Accrued interest receivable	(705)	255
Other assets	(14,501)	(3,350)
Accrued expenses and other liabilities	10,478	3,753
Net cash provided by operating activities	21,926	9,579
Activity in securities available for sale:
Purchases	0	(13,951)
Sales	0	213,084
Principal paydowns	0	5,049
Activity in securities held to maturity:
Purchases	(32,866)	(151,363)
Maturities/calls	0	25,000
Principal paydowns	29,868	23,557
Proceeds from sale of equity securities	4,772	0
Loan originations and purchases, net of paydowns	(110,498)	(219,759)
Net disposals (purchases) of premises and equipment	(430)	1,412
Purchase of FHLBB stock	(10,077)	(4,309)
Redemption of FHLBB stock	10,367	8,251
Proceeds from exchange of investment in Northeast Retirement Services	308	1,595
Net cash used in investing activities	(100,489)	(50,497)
Cash flows from financing activities:
Net change in deposits, excluding brokered deposits	108,553	200,869
Net change in brokered deposits	17,585	(24,003)
Net change in short-term borrowings	(2,000)	(126,000)
Net (repayments) proceeds from long-term debt	(25,000)	5,000
Share redemption for tax withholdings for restricted stock vesting	(345)	(107)
Proceeds from exercise of stock options, net	719	217
Common stock dividends paid	(19,367)	(7,191)
Net cash provided by financing activities	80,145	48,785
Net change in cash and cash equivalents	1,582	7,867
Cash and cash equivalents at beginning of period	46,167	30,496
Cash and cash equivalents at end of period	47,749	38,363
Supplementary information:
Interest paid	18,324	12,354
Income taxes paid, net of refunds	6,473	5,962
Other real estate owned acquired in settlement of loans	3,649	202
Common stock dividends declared	19,367	10,783
1-4 Family Residential
Activity in securities held to maturity:
Proceeds from sales of portfolios	7,207	51,661
Home Equity
Activity in securities held to maturity:
Proceeds from sales of portfolios	$ 0	$ 12,100

Basis of Presentation and Conso

Basis of Presentation and Consolidation	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Consolidation	BASIS OF PRESENTATION AND CONSOLIDATION Basis of Presentation The accompanying unaudited interim consolidated financial statements include the accounts of Blue Hills Bancorp, Inc. (the "Company"), its wholly-owned subsidiaries, Blue Hills Funding Corporation and Blue Hills Bank (the "Bank"), the principal operating entity, and the Bank's wholly-owned subsidiaries, B.H. Security Corporation, HP Security Corporation and 1196 Corporation, which are Massachusetts security corporations, and Nantucket Property Acquisition Company LLC, the Bank's subsidiary that holds other real estate owned. All significant intercompany balances and transactions have been eliminated in consolidation. The unaudited consolidated financial statements of the Company presented herein have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) for interim financial information and pursuant to the rules of the Securities and Exchange Commission ("SEC") for quarterly reports on Form 10-Q and Article 10 of Regulation S-X and do not include all of the information and note disclosures required by GAAP for a complete set of financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) and disclosures necessary for the fair presentation of the accompanying consolidated financial statements have been included. Interim results are not necessarily reflective of the results of the year. The accompanying unaudited financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2017, included in the Company's annual report on Form 10-K. 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 sheet and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the determination of the allowance for loan losses and the valuation of deferred tax assets. Merger On September 20, 2018, the Company entered into an Agreement and Plan of Merger (the "Merger Agreement") with Independent Bank Corp., a Massachusetts corporation ("Independent"), and Rockland Trust Company, a Massachusetts-chartered trust company and wholly owned subsidiary of Independent ("Rockland Trust"). Pursuant to the Merger Agreement, the Company will merge with and into Independent (the "Merger"), with Independent being the surviving corporation. Upon completion of the Merger, each outstanding share of Company common stock will convert into the right to receive 0.2308 shares of Independent common stock and $5.25 in cash (the "Merger Consideration"). Each outstanding option to acquire a share of Company common stock, whether or not vested, will be converted into the right to receive cash in an amount equal to the amount by which $26.25 exceeds the exercise price of the option. In addition, each award of Company restricted stock, whether or not vested, that is outstanding immediately prior to the effective time of the Merger will fully vest and be cancelled and converted into the right to receive the Merger Consideration. Following the merger of the Company with and into Independent, Blue Hills Bank will merge with Rockland Trust, with Rockland Trust being the surviving institution. Completion of the Merger is subject to customary closing conditions, including receipt of regulatory approvals and the approvals of the Company's and Independent's shareholders. The Merger is expected to close in the first half of 2019. Loan policies The Company has historically granted mortgage and consumer loans to its customers and a substantial portion of the loan portfolio consists of mortgage loans in communities including and near the locations of its banking offices. The ability of the Company’s debtors to honor their contracts is dependent upon the real estate and general economic conditions in these areas. The Company’s loan portfolio includes 1-4 family residential real estate, home equity, commercial real estate, construction, commercial business, and consumer segments. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off generally are reported at their outstanding unpaid principal balances adjusted for the allowance for loan losses, charge-offs, deferred origination fees and costs, and discounts on purchased loans. Interest income is accrued on the unpaid principal balance. Deferred loan origination fees/costs and discounts on purchased loans are recognized as an adjustment of the related loan yield using the interest method. It is the policy of the Company to discontinue the accrual of interest on loans past due in excess of 90 days, unless the loan is well-secured and in the process of collection. Accrual may be discontinued sooner when in the judgment of management, the ultimate collectability of the principal or interest becomes doubtful. Upon discontinuance of accrual, all interest previously accrued is reversed against interest income. Past due status is based on contractual terms of the loan. The interest on non-accrual loans is accounted for on the cash-basis until qualifying for return to accrual. Loans are returned to accrual status when all the principal and interest amounts contractually due have been current for six consecutive months and future payments are reasonably assured. Allowance for loan losses The allowance for loan losses is based on the size and the composition of the loan portfolio, delinquency levels, loss experience, economic conditions and other factors related to the collectability of the loan portfolio. Loss experience is updated at least quarterly with consideration given to unusual circumstances in the portfolio. Loan losses are charged against the allowance when management believes the uncollectability of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is evaluated regularly by management and reflects consideration of all significant factors that affect the collectability of the loan portfolio. The evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. It is the intention of management to maintain an allowance that is prudently commensurate with the growth in the loan portfolio. The allowance consists of general and allocated components, as further described below. General component The general component of the allowance for loan losses is based on a combination of the Company's own loss history and an extrapolated historical loss experience based on FDIC data for depository institutions with assets of one billion to five billion dollars dating back to 2010, adjusted for qualitative and environmental factors including changes to lending policies and procedures, economic and business conditions, portfolio characteristics, staff experience, problem loan trends, collateral values, concentrations and the competitive, legal and regulatory environment. The qualitative factors are determined based on the various risk characteristics of each loan segment. Risk characteristics relevant to each portfolio segment are as follows: Residential real estate - The Company does not generally originate loans with a loan-to-value ratio greater than 80 percent and does not generally grant loans that would be classified as subprime upon origination. When the Company does extend credit either on a first- or second-lien basis at a loan-to-value ratio greater than 80 percent , such loans are supported by either mortgage insurance or state guarantee programs. All loans in this segment are collateralized by owner-occupied, 1-4 family residential real estate and repayment is dependent on the credit quality of the individual borrower. The health of the national and state economy, including unemployment rates and housing prices, will have an effect on the credit quality of loans in this segment. Home equity - Loans in this segment are generally secured by first or second liens on residential real estate. Repayment is dependent on the credit quality of the individual borrower. The Company evaluates each loan application based on factors including the borrower’s credit score, income, length of employment, and other factors to establish the creditworthiness of the borrower. Commercial real estate - Loans in this segment include investment real estate and are generally secured by assignments of leases, real estate collateral and owner-occupied properties. In cases where there is a concentration of exposure to a single large tenant, underwriting standards include analysis of the tenant’s ability to support lease payments over the duration of the loan. The underlying cash flows generated by the properties may be adversely impacted by a downturn in the economy due to increased vacancy rates, which in turn can have an effect on the credit quality in this segment. Payments on loans secured by income-producing properties often depend on the successful operation and management of the properties. Management continually monitors the cash flows of these loans. Construction - Loans in this segment primarily include real estate development loans for which payment is derived from permanent financing or sale of the property. Credit risk is affected by cost overruns, time to sell at an adequate price, and market conditions. Commercial business - Loans in this segment are generally secured by business assets, including accounts receivable, inventory, real estate and intangible assets. Strict underwriting standards include considerations of the borrower’s ability to support the debt service requirements from the underlying historical and projected cash flows of the business, collateral values, the borrower’s credit history and the ultimate collectability of the de bt. Economic conditions, real estate values, commodity prices, unemployment trends and other factors will affect the credit quality of loans in these segments. Consumer - Loans in this segment primarily include used classic and collector automobile loans. A significant portion of the used automobile loan portfolio is comprised of geographically diverse loans originated by and purchased from a third party, who also provides collection services and shares equally in any losses incurred. Allocated component The allocated component relates to loans that are considered impaired. Impairment is measured by either the present value of expected future cash flows discounted at the loan’s effective interest rate or the fair value of the collateral if the loan is collateral dependent. An allowance is established when the discounted cash flows or collateral value of the impaired loan is lower than the carrying value of that loan. A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Management reviews all loan types for individual impairment. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. The Company periodically may agree to modify the contractual terms of loans. When a loan is modified and a concession is made to a borrower experiencing financial difficulty, the modification is considered a troubled debt restructuring (“TDR”). All TDRs are initially classified as impaired and generally remain impaired for the remaining life of the loan. The impaired classification may be removed if the borrower demonstrates compliance with the modified terms and the restructuring agreement specifies an interest rate equal to that which would be provided to a borrower with similar credit at the time of restructuring.

Accounting Standards Updates

Accounting Standards Updates	9 Months Ended
	Sep. 30, 2018
Accounting Changes and Error Corrections [Abstract]
Accounting Standards Updates	ACCOUNTING STANDARDS UPDATES Accounting Standards Adopted in the Period In August 2018, the FASB issued ASU 2018-14, " Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans." The guidance modifies disclosure requirements for defined benefit plans. This guidance is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. The Company is evaluating the provisions of this Update and the impact to the consolidated financial statements upon adoptions is not expected to be material. In August 2018, the FASB issued ASU 2018-13, “ Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement”, which adds disclosure requirements to Topic 820 for the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The Update is effective for all entities for fiscal years beginning after December 15, 2019, including interim periods therein. Early adoption is permitted for any eliminated or modified disclosures upon issuance of this Update. The Company is evaluating the provisions of this Update and the impact to the consolidated financial statements upon adoptions is not expected to be material. In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . The purpose of this Update is to allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The Company adopted the Update on January 1, 2018. The effect of applying the provisions of this Update resulted in an increase to retained earnings and a corresponding decrease in accumulated other comprehensive loss in the amount of $279,000 . Effective January 1, 2018, the Company adopted ASU 2016-01, Financial Instruments – Overall, (Subtopic 825-10) . The amendments in this Update address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. Targeted improvements to generally accepted accounting principles include the requirement for 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 and the elimination of the requirement for public business entities to disclose the methods and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost. The Update also requires Companies to utilize an "exit price" fair value methodology when measuring the fair value of financial instruments. The cumulative effect of applying the provisions of this Update resulted in an increase to retained earnings and a corresponding decrease to accumulated other comprehensive loss in the amount of $173,000 . Effective January 1, 2018, the Company adopted ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory . The amendments in this Update require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The impact to the consolidated financial statements upon adopting was not material. Effective January 1, 2018, the Company adopted ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash . The amendments in this Update require that in the statement of cash flows, amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts. The impact to the consolidated financial statements upon adopting was not material. Effective January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers . This Update provides a revenue recognition framework for any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets unless those contracts are within the scope of other accounting standards. The Company's revenue relates principally to financial instruments, which are explicitly excluded from the scope of the new guidance. The Company adopted this Update on January 1, 2018 and the impact to the consolidated financial statements upon adopting was not material. Effective January 1, 2018, the Company adopted ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting which amends the scope of modification accounting for share-based payment arrangements. The Update provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting. Specifically, an entity would not apply modification accounting if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. The Update should be applied prospectively to awards modified on or after the effective date. The impact to the consolidated financial statements upon adopting was not material. Recently Issued In July 2018, the FASB issued ASU 2018-10, Codification Improvements to Topic 842, Leases and ASU 2018-11, Leases . The guidance provides clarification on the application of ASU 2016-02, specifically on certain narrow aspects of the guidance issued under ASU 2016-02, including comparative reporting requirements for initial adoption and, for lessors only, separating lease and non-lease components in a contract and allocating the consideration in the contract to the separate components. For entities that have not adopted ASU 2016-02 before the issuance of these updates, the amendments in this guidance are the same as the effective date and transition requirements in ASU 2016-02. The adoption of this Update is not expected to have an impact on the Company’s consolidated financial statements. Future Application of Accounting Pronouncements Previously Issued In June 2018 the FASB issued ASU 2018-07 Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. The Updates expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. An entity should apply the requirements of Topic 718 to nonemployee awards except for specific guidance on inputs to an option pricing model and the attribution of cost (that is, the period of time over which share-based payment awards vest and the pattern of cost recognition over that period). The Update is effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The Company does not anticipate the adoption of ASU 2018-07 will have a material impact on its consolidated financial statements. In March 2018, the FASB issued ASU 2018-04, Investments-Debt Securities (Topic 320) and Regulated Operations (Topic 980) . Amendments to SEC paragraph Pursuant to SEC Staff Accounting Bulletin No. 177 and SEC Release No 33-9273, the amendment of ASU 2018-04 adds, amends and supersedes variance paragraphs that contain SEC guidance in ASC 320, Investments-Debt Securities and ASC 980, Regulated Operations. The Company does not anticipate the adoption of ASU 2018-04 will have a material impact on its consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities . The purpose of this Update is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. This Update is effective for public business entities for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period permitted. The Update requires a modified retrospective transition method in which the Company will recognize the cumulative effect of the change on the opening balance of each affected component of equity in the statement of financial position as of the date of adoption. While the Company continues to assess all potential impacts of the standard, the Company currently expects the adoption to have an immaterial impact on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) . This Update is intended to improve financial reporting about leasing transactions and the key provision impacting the Company is the requirement for a lessee to record a right-to-use asset and a liability representing the obligation to make lease payments for long-term operating leases. Additionally, the Update includes additional quantitative and qualitative disclosures required by lessees and lessors to help users better understand the amount, timing, and uncertainty of cash flows arising from leases. This Update is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply as well as transition guidance specific to nonstandard leasing transactions. The Company's assets and liabilities will increase based on the present value of remaining lease payments for leases in place at the adoption date; however, this is not expected to be material to the Company's results of operations or financial position. Future lease commitments as of at September 30, 2018 amounted to $19.9 million . In June, 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which removes the thresholds that companies apply to measure credit losses on financial instruments measured at amortized cost, such as loans, receivables, and held-to-maturity debt securities. Under current U.S. GAAP, companies generally recognize credit losses when it is probable that the loss has been incurred. The revised guidance will remove previously established recognition thresholds based on probability, and will require companies to recognize an allowance for credit losses for the difference between the amortized cost basis of a financial instrument and the net amount that the company expects to collect over the instrument’s contractual life. ASU 2016-13 also amends the credit loss measurement guidance for available-for-sale debt securities and will require that credit losses be recorded through an allowance for credit losses. Additionally, this Update may reduce the carrying value of the Company's held-to-maturity investment securities as it will require an allowance on the expected losses over the life of these securities to be recorded upon adoption. The ASU is effective for public business entities fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. Any increase in our allowance for loan losses or expenses may have a material adverse effect on our financial condition and results of operations. The Company is actively working through the provisions of the Update. Management has established a steering committee which has identified the methodologies and the additional data requirements necessary to implement the Update and has engaged a third-party software service provider to assist in the Company's implementation.

Securities

Securities	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	SECURITIES The amortized cost and estimated fair value of securities available for sale and securities held to maturity, with gross unrealized gains and losses, follows: September 30, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ 30,688 $ — $ (1,358 ) $ 29,330 Government-sponsored mortgage-backed and collateralized mortgage obligations 246,624 6 (9,668 ) 236,962 SBA asset-backed securities 28,623 32 (999 ) 27,656 Total securities held to maturity $ 305,935 $ 38 $ (12,025 ) $ 293,948 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available for Sale: Marketable equity securities $ 9,437 $ 755 $ (472 ) $ 9,720 Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ 30,673 $ — $ (894 ) $ 29,779 Government-sponsored mortgage-backed and collateralized mortgage obligations 244,668 30 (3,437 ) 241,261 SBA asset-backed securities 28,375 28 (329 ) 28,074 Total securities held to maturity $ 303,716 $ 58 $ (4,660 ) $ 299,114 The amortized cost and estimated fair value of debt securities by contractual maturity at September 30, 2018 are included in the following table. Expected maturities will differ from contractual maturities because the issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Based on expected maturities, the mortgage and asset-backed securities and collateralized mortgage obligations, included below, have a 4.0 year weighted average duration. Amortized Cost Fair Value (In thousands) Within 1 year $ 1,098 $ 1,088 After 1 year through 5 years 23,040 22,124 After 5 years through 10 years 6,550 6,118 30,688 29,330 Mortgage and asset-backed securities and collateralized mortgage obligations 275,247 264,618 $ 305,935 $ 293,948 At September 30, 2018 , net unrealized gains on equity securities held at the end of the period are $593,000 . For the three and nine months ended September 30, 2018 , proceeds from the sale of equity securities amounted to $4.8 million . For the three months ended September 30, 2017 , there were no proceeds from the sale of securities available for sale. For the nine months ended September 30, 2017 , proceeds from sales of securities available for sale amounted to $213.1 million , gross realized gains amounted $2.2 million , and gross realized losses amounted to $2.3 million . Information pertaining to securities with gross unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous loss position, follows: September 30, 2018 Less Than Twelve Months More Than Twelve Months Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (In thousands) Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ (65 ) $ 3,031 $ (1,293 ) $ 26,299 Government-sponsored mortgage-backed and collateralized mortgage obligations (1,608 ) 61,656 (8,060 ) 174,794 SBA asset-backed securities (194 ) 6,160 (805 ) 18,486 Total temporarily impaired securities held to maturity $ (1,867 ) $ 70,847 $ (10,158 ) $ 219,579 The Company continually reviews securities for the existence of other-than-temporary impairment ("OTTI"), taking into consideration current market conditions, the extent and nature of changes in fair value, issuer rating changes and trends, the credit worthiness of the obligor of the security, volatility of earnings, current analysts’ evaluations, the Company’s intent to sell the security, or whether it is more likely than not that the Company will be required to sell the security before its anticipated recovery, as well as other qualitative factors. The term “other-than-temporary” is not intended to indicate that the decline is permanent, but indicates that the prospects for a near-term recovery of value is not necessarily favorable, or that there is a lack of evidence to support a realizable value equal to or greater than the carrying value of the investment. At September 30, 2018 , multiple debt securities have unrealized losses with aggregate depreciation of approximately 4.0% from the Company’s amortized cost basis. The unrealized losses were primarily caused by interest rate fluctuations. It is expected that none of these securities would be settled at a price less than the par value of the investment. Because the decline in fair value is attributable to changes in interest rates and not to credit quality and it is more likely than not that the Company will recover their amortized cost bases by maturity, the Company does not consider these securities to be other-than-temporarily impaired at September 30, 2018 . Management has the ability and intent to hold the securities until maturity. December 31, 2017 Less Than Twelve Months More Than Twelve Months Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (In thousands) Securities Available for Sale: Temporarily impaired marketable equity securities $ (449 ) $ 4,310 $ (23 ) $ 443 Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ (109 ) $ 8,521 $ (785 ) $ 21,258 Government-sponsored mortgage-backed and collateralized mortgage obligations (1,563 ) 119,782 (1,874 ) 111,712 SBA asset-backed securities (34 ) 9,897 (295 ) 11,423 Total temporarily impaired securities held to maturity $ (1,706 ) $ 138,200 $ (2,954 ) $ 144,393

Loans and The Allowance for Loa

Loans and The Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2018
Receivables [Abstract]
Loans and The Allowance for Loan Losses	LOANS AND THE ALLOWANCE FOR LOAN LOSSES A summary of the balances of loans follows: September 30, December 31, 2018 2017 (In thousands) Real estate: 1-4 family residential $ 1,003,731 $ 922,627 Home equity 70,071 80,662 Commercial real estate 853,899 834,264 Construction 75,390 91,050 2,003,091 1,928,603 Commercial business 283,200 253,509 Consumer 16,889 21,698 Total loans 2,303,180 2,203,810 Allowance for loan losses (19,920 ) (20,877 ) Discount and fair value adjustments on purchased loans (1,126 ) (1,477 ) Deferred loan costs and fees, net 4,662 4,691 Loans, net $ 2,286,796 $ 2,186,147 Activity in the allowance for loan losses for the three and nine months ended September 30, 2018 and 2017 , by loan segment, follows: 1-4 Family Home Commercial Construction Commercial Consumer Total (In thousands) Three Months Ended September 30, 2018 Allowance at June 30, 2018 $ 5,372 $ 603 $ 8,992 $ 1,479 $ 3,389 $ 290 $ 20,125 Provision (credit) for loan losses (8 ) (27 ) 6 (323 ) 178 (8 ) (182 ) Loans charged-off — — — — — (23 ) (23 ) Recoveries — — — — — — — Allowance at September 30, 2018 $ 5,364 $ 576 $ 8,998 $ 1,156 $ 3,567 $ 259 $ 19,920 Three Months Ended September 30, 2017 Allowance at June 30, 2017 $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ 19,917 Provision (credit) for loan losses (3 ) 61 (153 ) 169 159 9 242 Loans charged-off — — — — — (36 ) (36 ) Recoveries 125 — — — — — 125 Allowance at September 30, 2017 $ 5,095 $ 670 $ 8,834 $ 1,779 $ 3,511 $ 359 $ 20,248 Nine Months Ended September 30, 2018 Allowance at December 31, 2017 $ 5,076 $ 699 $ 9,584 $ 1,708 $ 3,473 $ 337 $ 20,877 Provision (credit) for loan losses 288 (123 ) (392 ) (552 ) 261 (23 ) (541 ) Loans charged-off — — (194 ) — (178 ) (63 ) (435 ) Recoveries — — — — 11 8 19 Allowance at September 30, 2018 $ 5,364 $ 576 $ 8,998 $ 1,156 $ 3,567 $ 259 $ 19,920 Nine Months Ended September 30, 2017 Allowance at December 31, 2016 $ 4,846 $ 537 $ 8,374 $ 1,353 $ 3,206 $ 434 $ 18,750 Provision (credit) for loan losses 102 133 460 426 296 — 1,417 Loans charged-off (52 ) — — — — (75 ) (127 ) Recoveries 199 — — — 9 — 208 Allowance at September 30, 2017 $ 5,095 $ 670 $ 8,834 $ 1,779 $ 3,511 $ 359 $ 20,248 Additional information pertaining to the allowance for loan losses at September 30, 2018 and December 31, 2017 is as follows: 1-4 Family Home Commercial Construction Commercial Consumer Total (In thousands) September 30, 2018 Allowance related to impaired loans $ 45 $ — $ — $ — $ — $ — $ 45 Allowance related to non-impaired loans 5,319 576 8,998 1,156 3,567 259 19,875 Total allowance for loan losses $ 5,364 $ 576 $ 8,998 $ 1,156 $ 3,567 $ 259 $ 19,920 Impaired loans $ 6,801 $ 1,814 $ 3,386 $ — $ 163 $ 99 $ 12,263 Non-impaired loans 996,930 68,257 850,513 75,390 283,037 16,790 2,290,917 Total loans $ 1,003,731 $ 70,071 $ 853,899 $ 75,390 $ 283,200 $ 16,889 $ 2,303,180 December 31, 2017 Allowance related to impaired loans $ 80 $ — $ — $ — $ — $ 1 $ 81 Allowance related to non-impaired loans 4,996 699 9,584 1,708 3,473 336 20,796 Total allowance for loan losses $ 5,076 $ 699 $ 9,584 $ 1,708 $ 3,473 $ 337 $ 20,877 Impaired loans $ 5,949 $ 1,387 $ 4,744 $ — $ — $ 202 $ 12,282 Non-impaired loans 916,678 79,275 829,520 91,050 253,509 21,496 2,191,528 Total loans $ 922,627 $ 80,662 $ 834,264 $ 91,050 $ 253,509 $ 21,698 $ 2,203,810 The following is a summary of past due and non-accrual loans, by loan class, at September 30, 2018 and December 31, 2017 : 30-59 Days Past Due 60-89 Days Past Due Past Due 90 Days or More Total Past Due Loans on Non-accrual (In thousands) September 30, 2018 Real estate: 1-4 family residential $ 970 $ 664 $ 1,607 $ 3,241 $ 6,339 Home equity 483 692 434 1,609 1,814 Commercial real estate — — — — 3,386 Commercial business — — — — 163 Consumer 95 — 25 120 82 Total $ 1,548 $ 1,356 $ 2,066 $ 4,970 $ 11,784 December 31, 2017 Real estate: 1-4 family residential $ 381 $ 348 $ 2,184 $ 2,913 $ 5,190 Home equity 509 13 656 1,178 1,387 Commercial real estate — — 3,893 3,893 4,744 Consumer 107 7 92 206 202 Total $ 997 $ 368 $ 6,825 $ 8,190 $ 11,523 There were no loans past due 90 days or more and still accruing interest at September 30, 2018 and December 31, 2017 . The following is a summary of information pertaining to impaired loans by loan class at the dates indicated: Recorded Investment Unpaid Principal Balance Related Allowance September 30, 2018 (In thousands) Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 5,447 $ 5,844 $ — Home equity 1,814 1,944 — Commercial real estate 3,386 3,543 — Commercial business 163 314 — Consumer 99 113 — Total 10,909 11,758 — Impaired loans with a valuation allowance: 1-4 family residential 1,354 1,354 45 Total impaired loans $ 12,263 $ 13,112 $ 45 December 31, 2017 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,501 $ 4,897 $ — Home equity 1,387 1,523 — Commercial real estate 4,744 5,206 — Commercial business — 11 — Consumer 191 243 — Total 10,823 11,880 — Impaired loans with a valuation allowance: Real estate: 1-4 family residential 1,448 1,448 80 Consumer 11 11 1 Total 1,459 1,459 81 Total impaired loans $ 12,282 $ 13,339 $ 81 The following tables set forth information regarding average balances and interest income recognized (the majority of which is on a cash basis) on impaired loans by class, for the periods indicated: Average Recorded Investment Interest Income Recognized Three Months Ended September 30, 2018 (In thousands) Real estate: 1-4 family residential $ 6,331 $ 75 Home equity 2,019 20 Commercial real estate 2,850 30 Commercial business 171 6 Consumer 97 1 Total $ 11,468 $ 132 Three Months Ended September 30, 2017 Real estate: 1-4 family residential $ 6,041 $ 60 Home equity 1,198 6 Commercial real estate 4,933 172 Commercial business 89 — Consumer 340 2 Total $ 12,601 $ 240 Nine Months Ended September 30, 2018 Real estate: 1-4 family residential $ 6,159 $ 225 Home equity 1,688 65 Commercial real estate 3,210 76 Commercial business 162 14 Consumer 122 4 Total $ 11,341 $ 384 Nine Months Ended September 30, 2017 Real estate: 1-4 family residential $ 6,330 $ 220 Home equity 1,234 35 Commercial real estate 3,970 207 Commercial business 161 5 Consumer 251 7 Total $ 11,946 $ 474 No additional funds are committed to be advanced in connection with impaired loans. There were no troubled debt restructurings entered into during the three months ended September 30, 2018. Troubled debt restructurings entered into during the nine months ended September 30, 2018 are as follows: Nine Months Ended September 30, 2018 Number of contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Real estate: 1-4 family residential 3 $ 469 $ 475 Home equity 1 359 359 Commercial real estate 1 1,563 1,563 Total 5 $ 2,391 $ 2,397 There were no material troubled debt restructurings recorded during the three and nine months ended September 30, 2017 . Loans modified during the three and nine months ended September 30, 2018 were modified to capitalize past due interest for 1-4 family residential and home equity loans and extend interest only periods for commercial real estate loans. Credit Quality Information The Company utilizes a ten-grade internal loan rating system for all loans as follows: Loans rated 1 – 6 are considered “acceptable” rated loans that are performing as agreed, and generally require only routine supervision. Loans rated 7 are considered “special mention.” These loans are starting to show signs of potential weakness and are being closely monitored by management. Loans rated 8 are considered “substandard.” Generally, a loan is considered substandard if it is inadequately protected by the current net worth and paying capacity of the obligors and/or the collateral pledged. There is a distinct possibility that the Company will sustain some loss if the weakness is not corrected. Generally, all loans 90 days delinquent are rated 8. Loans rated 9 are considered “doubtful.” Serious problems exist to the point where a partial loss of principal is likely. Weakness is so pronounced that on the basis of current information, conditions and values, collection in full is highly improbable. Loans rated 10 are considered "loss" and the credit extended to the customer is considered uncollectible or of such little value that it does not warrant consideration as an active asset. The Company assigns a 6 risk-rating to otherwise performing, satisfactorily collateralized consumer and residential loans where the Bank becomes aware of deterioration in a FICO score or other indication of potential inability to service the debt. The Company assigns risk ratings of 7-10 to residential or consumer loans that have a well-defined weakness that may jeopardize the collection of the contractual principal and interest, are contractually past due 90 days or more or legal action has commenced against the borrower. All other residential mortgage and consumer loans have no risk rating. On an annual basis, or more often if needed, the Company formally reviews the ratings on all commercial and commercial construction loans. At least annually, the Company engages an independent third party to review a significant portion of loans within these segments. Management uses the results of these reviews as part of its annual review process. In addition, management utilizes delinquency reports, the watch list and other loan reports to monitor credit quality of other loan segments. The following tables present the Company’s loans by risk rating at September 30, 2018 and December 31, 2017 : 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Total Loans (In thousands) September 30, 2018 Loans rated 1 - 6 $ 994 $ 328 $ 841,437 $ 75,390 $ 266,574 $ 3 $ 1,184,726 Loans rated 7 3,694 1,853 5,316 — 15,534 82 26,479 Loans rated 8 2,750 — 7,146 — 1,092 16 11,004 Loans rated 9 242 — — — — — 242 Loans rated 10 — — — — — — — Loans not rated 996,051 67,890 — — — 16,788 1,080,729 $ 1,003,731 $ 70,071 $ 853,899 $ 75,390 $ 283,200 $ 16,889 $ 2,303,180 December 31, 2017 Loans rated 1 - 6 $ 1,022 $ 270 $ 821,815 $ 91,050 $ 252,765 $ 3 $ 1,166,925 Loans rated 7 2,848 1,523 4,660 — 744 121 9,896 Loans rated 8 2,566 — 7,789 — — — 10,355 Loans rated 9 250 — — — — — 250 Loans rated 10 — — — — — — — Loans not rated 915,941 78,869 — — — 21,574 1,016,384 $ 922,627 $ 80,662 $ 834,264 $ 91,050 $ 253,509 $ 21,698 $ 2,203,810

Other Real Estate Owned

Other Real Estate Owned	9 Months Ended
	Sep. 30, 2018
Banking and Thrift [Abstract]
Other Real Estate Owned	OTHER REAL ESTATE OWNED Assets acquired through, or in lieu of, loan foreclosure are held for sale and are initially recorded at fair value, less cost to sell, at the date of foreclosure, establishing a new cost basis. Subsequent to foreclosure, valuations are periodically performed by management and the assets are carried at the lower of carrying amount or fair value less cost to sell. Revenue and expenses from operations, changes in the valuation allowance and any direct writedowns are included in net expenses from foreclosed assets. At September 30, 2018 , other real estate owned consists of one commercial real estate property that the Company foreclosed on during the nine months ended September 30, 2018 . The balance was $3.6 million as of September 30, 2018 . There was no balance as of December 31, 2017 . Noninterest expenses applicable to foreclosed assets were $12,000 and $84,000 during the three and nine months ended September 30, 2018 , respectively. Noninterest expenses applicable to foreclosed assets were $2,000 and $11,000 for the three and nine months ended September 30, 2017 , respectively.

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES Interest Rate Swap Agreements The Company is party to derivative financial instruments in the normal course of business to manage exposure to fluctuations in interest rates and to meet the needs of commercial customers. These financial instruments have been generally limited to loan level interest rate swap agreements, which are entered into with counterparties that meet established credit standards. These transactions involve both credit and market risk. The notional amounts are amounts on which calculations, payments, and the value of the derivatives are based. Notional amounts do not represent direct credit exposures. The fair value of the derivative instruments is reflected on the Company’s consolidated balance sheet as other assets or accrued expenses and other liabilities as appropriate. Changes in the fair value of these agreements are recorded in miscellaneous income in the consolidated statements of net income. The table below presents information about derivative financial instruments not designated as hedging instruments at September 30, 2018 and December 31, 2017 . Derivative Gains Derivative Losses Notional Amount Fair Value Notional Amount Fair Value (In thousands) September 30, 2018 Economic hedges: Commercial loan level interest rate swap agreements $ 629,078 $ 18,458 $ 629,078 $ 18,458 Other contracts 37,212 35 46,507 26 Total derivatives $ 666,290 $ 18,493 $ 675,585 $ 18,484 December 31, 2017 Economic hedges: Commercial loan level interest rate swap agreements $ 582,388 $ 8,741 $ 582,388 $ 8,741 Other contracts 27,689 25 54,293 44 Total derivatives $ 610,077 $ 8,766 $ 636,681 $ 8,785 The Company is exposed to credit-related losses in the event of nonperformance by the counterparties to these agreements. The Company controls the credit risk of its financial contracts through credit approvals, limits and monitoring procedures, and does not expect any counterparties to fail their obligations. The Company has minimum collateral posting thresholds with certain of its interest rate swap derivative counterparties. Other contracts represent risk participation agreements on commercial loan level interest rate swap agreements. The Company has entered into risk participation agreements with the correspondent institutions to share in any interest rate swap gains or losses incurred as a result of the commercial loan customers’ termination of a loan level interest rate swap agreement prior to maturity. The Company records these risk participation agreements at fair value. Mortgage Banking Derivatives The Company enters into commitments to fund residential mortgage loans at specified rates and times in the future, with the intention that loans will subsequently be sold in the secondary market. Mortgage loan commitments are referred to as derivative loan commitments if the loan that will result from exercise of the commitment will be held for sale upon funding. These commitments are recognized at fair value on the consolidated balance sheet in other assets and other liabilities with changes in their fair values recorded in non-interest income. Outstanding loan commitments expose the Company to the risk that the price of the loans arising from exercise of the loan commitment might change from inception of the rate lock to funding of the loan due to changes in mortgage interest rates. If interest rates increase, the value of these loan commitments decreases. Conversely, if interest rates decrease, the value of these loan commitments increases. To protect against the price risk inherent in derivative loan commitments, the Company utilizes both "mandatory delivery" and "best efforts" forward loan sale commitments to mitigate the risk of potential decreases in the values of loans that would result from the exercise of the derivative loan commitments. Mandatory delivery contracts are accounted for as derivative instruments. Included in the mandatory delivery forward commitments are To Be Announced securities (“TBAs”). Mandatory delivery forward loan sale commitments are recognized at fair value on the consolidated balance sheet in other assets and other liabilities with changes in their fair values recorded in mortgage banking income. With best effort contracts, the Company commits to deliver an individual mortgage loan of a specified principal amount and quality to an investor if the loan to the underlying borrower closes. Generally best efforts cash contracts have no pair off risk regardless of market movement. The price the investor will pay the seller for an individual loan is specified prior to the loan being funded (e.g., on the same day the lender commits to lend funds to a potential borrower). The Company expects that these best efforts forward loan sale commitments will experience a net neutral shift in fair value with related derivative loan commitments. With mandatory delivery contracts, the Company commits to deliver a certain principal amount of mortgage loans to an investor at a specified price on or before a specified date. If the Company fails to deliver the amount of mortgages necessary to fulfill the commitment by the specified date, it is obligated to pay a “pair-off” fee, based on then-current market prices, to the investor/counterparty to compensate the investor for the shortfall. Generally the Company makes this type of commitment once mortgage loans have been funded and are held for sale, in order to minimize the risk of failure to deliver the requisite volume of loans to the investor and paying pair-off fees as a result. The Company also sells TBA securities to offset potential changes in the fair value of derivative loan commitments. Generally the Company sells TBA securities upon entering derivative loan commitments for settlement in 30 to 90 days . The Company expects that mandatory delivery contracts, including TBA securities, will experience changes in fair value opposite to the changes in the fair value of derivative loan commitments. At September 30, 2018 , the Company had $10.6 million of interest rate lock commitments to borrowers and loans held for sale of $947,000 with $11.6 million of forward commitments for the future delivery of residential mortgage loans on a best efforts basis. At September 30, 2018 , the Company had $18.3 million of interest rate lock commitments to borrowers and loans held for sale of $4.1 million with $22.4 million of forward commitments for the future delivery of residential mortgage loans on a mandatory delivery basis. Included in the forward commitments are open TBAs with a notional amount of $16.0 million and $12.0 million of closed hedge instruments that are not settled at September 30, 2018 . At December 31, 2017 , the Company had $16.4 million of loan commitments to borrowers and loans held for sale of $8.9 million with $25.3 million of forward commitments for the future delivery of residential mortgage loans on a best efforts basis. The Company did no t have any commitments under mandatory delivery at December 31, 2017 . The fair value of such commitments as of September 30, 2018 and December 31, 2017 are outlined below: Assets Liabilities Balance sheet location Fair Value Balance sheet location Fair Value (In thousands) September 30, 2018 Derivative loan commitments: Mortgage loan commitments best efforts Other assets $ 73 Other liabilities $ 6 Mortgage loan commitments mandatory delivery Other assets 160 Other liabilities 3 Total mortgage derivative commitments $ 233 $ 9 Forward loan sale commitments: Forward loan sale commitments best efforts Other assets $ 8 Other liabilities $ 11 Forward loan sale commitments mandatory delivery Other assets 53 Other liabilities 9 Total forward loan sale commitments $ 61 $ 20 Total $ 294 $ 29 December 31, 2017 Derivative loan commitments: Mortgage loan commitments best efforts Other assets $ 210 Other liabilities $ 36 Total mortgage derivative commitments $ 210 $ 36 Forward loan sale commitments: Forward loan sale commitments best efforts Other assets $ 22 Other liabilities $ 69 Total forward loan sale commitments $ 22 $ 69 Total $ 232 $ 105

Deposits

Deposits	9 Months Ended
	Sep. 30, 2018
Banking and Thrift [Abstract]
Deposits	DEPOSITS A summary of deposit balances, by type, is as follows: September 30, December 31, 2018 2017 (In thousands) NOW and demand $ 415,993 $ 381,316 Regular savings 206,726 221,004 Money market 620,529 646,603 Brokered money market 80,143 92,798 Total non-certificate accounts 1,323,391 1,341,721 Term certificates of $250,000 or more 179,926 134,649 Term certificates less than $250,000 382,684 313,733 Brokered term certificates 280,006 249,766 Total term certificate accounts 842,616 698,148 Total deposits $ 2,166,007 $ 2,039,869 At September 30, 2018 , the scheduled maturities of term certificate accounts, including brokered deposits, are as follows: Amount Weighted Average Rate (Dollars in thousands) Within 1 year $ 515,442 1.79 % 1-2 years 201,257 1.98 2-3 years 92,326 2.49 3-4 years 28,191 2.07 4 years and beyond 5,400 1.67 $ 842,616 1.92 %

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Determination of fair value The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various assets and liabilities. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the asset or liability. Assets and liabilities measured at fair value on a recurring basis Assets and liabilities measured at fair value on a recurring basis are summarized below: Level 1 Level 2 Level 3 Total Fair Value (In thousands) September 30, 2018 Assets Equity securities, at fair value $ 5,270 $ — $ — $ 5,270 Derivative assets: Interest rate swap agreements — 18,493 — 18,493 Forward loan sale commitments - best efforts — — 8 8 Forward loan sale commitments - mandatory delivery — — 53 53 Mortgage loan commitments - best efforts — — 73 73 Mortgage loan commitments - mandatory delivery — — 160 160 Total assets $ 5,270 $ 18,493 $ 294 $ 24,057 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 18,484 $ — $ 18,484 Forward loan sale commitments - best efforts — — 11 11 Forward loan sale commitments - mandatory delivery — — 9 9 Mortgage loan commitments - best efforts — — 6 6 Mortgage loan commitments - mandatory delivery — — 3 3 Total liabilities $ — $ 18,484 $ 29 $ 18,513 December 31, 2017 Assets Securities available for sale: Marketable equity securities $ 9,720 $ — $ — $ 9,720 Derivative assets: Interest rate swap agreements — 8,766 — 8,766 Forward loan sale commitments - best efforts — — 22 22 Mortgage loan commitments - best efforts — — 210 210 Total assets $ 9,720 $ 8,766 $ 232 $ 18,718 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 8,785 $ — $ 8,785 Forward loan sale commitments - best efforts — — 69 69 Mortgage loan commitments - best efforts — — 36 36 Total liabilities $ — $ 8,785 $ 105 $ 8,890 The following methods and assumptions were used by the Company in estimating fair value: Securities : All fair value measurements are obtained from a third-party pricing service and are not adjusted by management. The securities measured at fair value in Level 1 are based on quoted market prices in an active exchange market. These securities include U.S. Treasury securities and marketable equity securities. All other securities are measured at fair value in Level 2 based on pricing models that consider standard input factors such as observable market data, benchmark yields, interest rate volatilities, broker/dealer quotes, credit spreads and new issue data. Interest rate swap agreements : The fair values of interest rate swap agreements are based on a valuation model that uses primarily observable inputs, such as benchmark yield curves and interest rates and also include the value associated with counterparty credit risk. Credit risk adjustments consider factors such as the likelihood of default by the Company and its counterparties, its net exposures and remaining contractual life. To date, the Company has not realized any losses due to a counterparty's inability to pay any net uncollateralized position. Forward loan sale commitments and derivative loan commitments : Fair values of forward loan sale commitments and derivative loan commitments are based on changes in the fair values of the underlying mortgage loans from inception and, for derivative loan commitments, fair values also include the value of servicing, deferred origination fees/costs and the probability of such commitments being exercised. Significant management judgment and estimation is required in determining these fair value measurements. Assets measured at fair value on a non-recurring basis The Company may also be required, from time to time, to measure certain assets at fair value on a non-recurring basis in accordance with generally accepted accounting principles. These adjustments to fair value usually result from application of lower-of-cost-or-market accounting or write-downs of individual assets. There are no liabilities measured at fair value on a non-recurring basis. The following table summarizes the fair value hierarchy applicable to assets measured at fair value on a non-recurring basis: September 30, 2018 December 31, 2017 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 (In thousands) Impaired loans $ — $ — $ 1,517 $ — $ — $ 2,214 Other real estate owned — — 3,649 — — — $ — $ — $ 5,166 $ — $ — $ 2,214 The following table summarizes the total gains (losses) on assets measured at fair value on a non-recurring basis for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Impaired loans $ 4 $ 11 $ (346 ) $ 2 Gains and losses applicable to impaired loans are based on the appraised value of the underlying collateral, discounted as necessary due to management’s estimates of changes in market conditions. The gains and losses applicable to impaired loans are not recorded as a direct adjustment to current earnings or comprehensive income, but rather as a component in determining the overall adequacy of the allowance for loan losses. Adjustments to the estimated fair value of impaired loans may result in increases or decreases to the provision for loan losses. Summary of fair values of financial instruments The estimated fair values, and related carrying amounts, of the Company’s financial instruments are as follows. Certain financial instruments and all nonfinancial instruments are exempt from disclosure requirements. Accordingly, the aggregate fair value amounts presented herein do not represent the underlying fair value of the Company. Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) September 30, 2018 Financial assets: Cash and cash equivalents $ 47,749 $ 47,749 $ — $ — $ 47,749 Equity securities at fair value 5,270 5,270 — — 5,270 Securities held to maturity 305,935 — 293,948 — 293,948 Federal Home Loan Bank stock 11,815 — — 11,815 11,815 Loans and loans held for sale, net 2,291,831 — — 2,267,797 2,267,797 Accrued interest receivable 7,143 — — 7,143 7,143 Financial liabilities: Deposits 2,166,007 — — 2,160,039 2,160,039 Borrowings 178,000 — 176,902 — 176,902 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 18,493 — 18,493 — 18,493 Forward loan sale commitments - best efforts 8 — — 8 8 Forward loan sale commitments - mandatory delivery 53 — — 53 53 Mortgage loan commitments - best efforts 73 — — 73 73 Mortgage loan commitments-mandatory delivery 160 — — 160 160 Derivative liabilities: Interest rate swap agreements 18,484 — 18,484 — 18,484 Forward loan sale commitments - best efforts 11 — — 11 11 Forward loan sale commitments - mandatory delivery 9 — — 9 9 Mortgage loan commitments - best efforts 6 — — 6 6 Mortgage loan commitments - mandatory delivery 3 — — 3 3 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) December 31, 2017 Financial assets: Cash and cash equivalents $ 46,167 $ 46,167 $ — $ — $ 46,167 Securities available for sale 9,720 9,720 — — 9,720 Securities held to maturity 303,716 — 299,114 — 299,114 Federal Home Loan Bank stock 12,105 — — 12,105 12,105 Loans and loans held for sale 2,195,139 — — 2,174,871 2,174,871 Accrued interest receivable 6,438 — — 6,438 6,438 Financial liabilities: Deposits 2,039,869 — — 2,036,150 2,036,150 Borrowings 205,000 — 203,913 — 203,913 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 8,766 — 8,766 — 8,766 Forward loan sale commitments - best efforts 22 — — 22 22 Mortgage loan commitments - best efforts 210 — — 210 210 Derivative liabilities: Interest rate swap agreements 8,785 — 8,785 — 8,785 Forward loan sale commitments - best efforts 69 — — 69 69 Mortgage loan commitments - best efforts 36 — — 36 36

Comprehensive Income

Comprehensive Income	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Comprehensive Income	COMPREHENSIVE INCOME Accounting principles generally require that recognized revenues, expenses, gains and losses be included in net income. Although certain changes in assets and liabilities are reported as a separate component of stockholders' equity on the consolidated balance sheets, such items, along with net income, are components of comprehensive income. The components of accumulated other comprehensive loss, included in stockholders' equity, are as follows: September 30, December 31, 2018 2017 (In thousands) Securities available for sale: Net unrealized gain $ — $ 283 Tax effect — (140 ) Net-of-tax amount — 143 Securities held to maturity: Net unrealized gain on transferred securities 187 250 Tax effect (15 ) (66 ) Net-of-tax amount 172 184 Defined benefit pension plan: Unrecognized net actuarial loss (2,495 ) (2,694 ) Tax effect 514 914 Net-of-tax amount (1,981 ) (1,780 ) $ (1,809 ) $ (1,453 )

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS' EQUITY Minimum regulatory capital requirements The Company (on a consolidated basis) and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory, and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s and the Bank’s consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of their assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. Prompt corrective action provisions are not applicable to bank holding companies. Federal banking regulations include minimum capital ratios as displayed in the following table. Additionally, community banking institutions must maintain a capital conservation buffer of common equity Tier 1 capital in an amount greater than 2.5% of total risk-weighted assets to avoid being subject to limitations on capital distributions and discretionary bonuses. The capital conservation buffer is being phased in over multiple years, with an initial phase-in of 0.625% . Beginning on January 1, 2018, the capital conservation buffer is 1.875% . Also, certain deductions from and adjustments to regulatory capital are being phased in over several years. Management believes that the Company will remain characterized as “well capitalized” throughout the phase-in periods. The application of the capital conservation buffer resulted in no limitations to payout of retained earnings as of September 30, 2018 . As of September 30, 2018 , the most recent notification from the Federal Deposit Insurance Corporation categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized, an institution must maintain minimum ratios as set forth in the following tables. There are no conditions or events since the notification that management believes have changed the Bank's category. Management believes, as of September 30, 2018 and December 31, 2017 , that the Company and the Bank meet all capital adequacy requirements to which they are subject. The Company's and the Bank's actual capital amounts and ratios as of September 30, 2018 and December 31, 2017 are also presented in the following table. Actual Minimum Capital Requirement Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) Blue Hills Bancorp, Inc.: September 30, 2018 Total capital (to risk weighted assets) $ 415,901 18.3 % $ 182,234 8.0 % $ 227,793 10.0 % Tier 1 capital (to risk weighted assets) 395,981 17.4 136,676 6.0 182,234 8.0 Common equity Tier 1 (to risk weighted assets) 395,981 17.4 102,507 4.5 148,065 6.5 Tier 1 capital (to average assets) 395,981 14.4 109,770 4.0 137,212 5.0 December 31, 2017 Total capital (to risk weighted assets) $ 410,088 19.7 % $ 166,635 8.0 % $ 208,294 10.0 % Tier 1 capital (to risk weighted assets) 389,211 18.7 124,977 6.0 166,635 8.0 Common equity Tier 1 (to risk weighted assets) 389,211 18.7 93,732 4.5 135,391 6.5 Tier 1 capital (to average assets) 389,211 14.9 104,278 4.0 130,348 5.0 Blue Hills Bank: September 30, 2018 Total capital (to risk weighted assets) $ 365,926 16.1 % $ 182,059 8.0 % $ 227,574 10.0 % Tier 1 capital (to risk weighted assets) 346,006 15.2 136,544 6.0 182,059 8.0 Common equity Tier 1 (to risk weighted assets) 346,006 15.2 102,408 4.5 147,923 6.5 Tier 1 capital (to average assets) 346,006 12.6 109,664 4.0 137,080 5.0 December 31, 2017 Total capital (to risk weighted assets) $ 341,175 16.4 % $ 166,391 8.0 % $ 207,988 10.0 % Tier 1 capital (to risk weighted assets) 320,298 15.4 124,793 6.0 166,391 8.0 Common equity Tier 1 (to risk weighted assets) 320,298 15.4 93,595 4.5 135,192 6.5 Tier 1 capital (to average assets) 320,298 12.3 104,137 4.0 130,171 5.0 As a result of the recently enacted Economic Growth, Regulatory Relief, and Consumer Protection Act (the “Act”), banking regulatory agencies must adopt a revised definition of “well capitalized” for financial institutions and holding companies with assets of less than $10 billion and that are not determined to be ineligible by their primary federal regulator due to their risk profile (a “qualifying community bank”). The new definition will expand the ways that a qualifying community bank may meet its capital requirements and be deemed “well capitalized.” The new rule will establish a “community bank leverage ratio” equal to the tangible equity capital divided by the average total consolidated assets. A qualifying community bank that exceeds a to-be-determined threshold for this new leverage ratio, which regulators must set at between 8% and 10%, will be considered to be well capitalized and to have met generally applicable leverage capital requirements, generally applicable risk-based capital requirements, and any other capital or leverage requirements to which such financial institution or holding company is subject. In addition, as a result of the Act, the Federal Reserve Board is required to amend its small bank holding company and savings and loan holding company policy statement to provide that holding companies with consolidated assets of less than $3 billion that are (i) not engaged in significant nonbanking activities, (ii) do not conduct significant off-balance sheet activities, and (3) do not have a material amount of SEC-registered debt or equity securities, other than trust preferred securities, that contribute to an organization’s complexity, will no longer be subject to regulatory capital requirements, effective no later than November 2018.

Employee Stock Ownership Plan

Employee Stock Ownership Plan	9 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Employee Stock Ownership Plan	EMPLOYEE STOCK OWNERSHIP PLAN The Company maintains an Employee Stock Ownership Plan (“ESOP”) to provide eligible employees the opportunity to own Company stock. This plan is a tax-qualified retirement plan for the benefit of Company employees. Contributions are allocated to eligible participants on the basis of compensation, subject to federal tax limits. The number of shares committed to be released per year is 75,912 through 2043. Shares held by the ESOP include the following: September 30, 2018 December 31, 2017 Allocated 291,617 219,860 Committed to be allocated 56,778 75,912 Unallocated 1,916,919 1,973,699 2,265,314 2,269,471 The fair value of unallocated shares was $46.2 million and $39.7 million at September 30, 2018 and December 31, 2017 , respectively. Total compensation expense recognized in connection with the ESOP for the three months ended September 30, 2018 and 2017 was $434,000 and $357,000 , respectively. Total compensation expense recognized in connection with the ESOP for the nine months ended September 30, 2018 and 2017 was $1.2 million and $1.0 million , respectively.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Common Share	EARNINGS PER COMMON SHARE Basic earnings per common share represents income available to common stockholders divided by the weighted-average number of common shares outstanding during the period. Unallocated ESOP shares are not deemed outstanding for earnings per share calculations. Three Months Ended September 30, 2018 2017 (In thousands, except share amounts) Net income applicable to common stock $ 5,789 $ 3,841 Average number of common shares outstanding 26,894,607 26,865,148 Less: Average unallocated ESOP shares (1,926,486 ) (2,002,397 ) Less: Average unvested restricted stock awards (711,219 ) (889,635 ) Average number of common shares outstanding used to calculate basic earnings per common share 24,256,902 23,973,116 Effect of dilutive stock options 664,345 240,806 Effect of dilutive unvested restricted stock awards 321,490 296,170 Average number of common shares outstanding used to calculate diluted earnings per common share 25,242,737 24,510,092 Earnings per common share: Basic $ 0.24 $ 0.16 Diluted $ 0.23 $ 0.16 Nine Months Ended September 30, 2018 2017 (In thousands, except share amounts) Net income applicable to common stock $ 18,829 $ 15,196 Average number of common shares outstanding 26,875,768 26,855,598 Less: Average unallocated ESOP shares (1,945,309 ) (2,021,219 ) Less: Average unvested restricted stock awards (710,404 ) (888,494 ) Average number of common shares outstanding used to calculate basic earnings per common share 24,220,055 23,945,885 Effect of dilutive stock options 534,257 178,712 Effect of dilutive unvested restricted stock awards 266,846 253,065 Average number of common shares outstanding used to calculate diluted earnings per common share 25,021,158 24,377,662 Earnings per common share: Basic $ 0.78 $ 0.63 Diluted $ 0.75 $ 0.62 Options for 236,056 and 589,746 shares were not included in the computation of diluted earnings per common share because to do so would have been anti-dilutive for the three and nine months ended September 30, 2018 , respectively. Options for 407,950 shares were not included in the computation of diluted earnings per common share because to do so would have been anti-dilutive for the three and nine months ended September 30, 2017 .

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	SHARE-BASED COMPENSATION Under the Blue Hills Bancorp, Inc. 2015 Equity Incentive Plan (the "Equity Plan"), the Company may grant options, restricted stock, restricted units or performance awards to its directors, officers and employees. Both incentive stock options and non-qualified stock options may be granted under the Equity Plan, with the total shares reserved for options equaling 2,846,681 . Board members may only receive non-qualified stock options. The exercise price of each option equals the market price of the Company’s stock on the date of grant and the maximum term of each option is ten years. A total of 1,138,673 shares are reserved for awards of restricted stock or restricted units. The vast majority of options and awards vest ratably over five years. The fair value of shares awarded is based on the market price at the date of grant. Expense related to options and restricted stock granted to directors is recognized as directors' fees within noninterest expense. The Company has standard form agreements used for stock option and restricted stock awards. The standard form agreements used for the Chief Executive Officer and all other Executive Officers have previously been disclosed in Securities and Exchange Commission filings and generally provide that: (1) any unvested options or unvested restricted stock vest upon a Change in Control; and, that (2) any stock options which vest pursuant to a Change in Control, which is an event described in Section 280G of the Internal Revenue Code of 1986, will be cashed out at the difference between the acquisition price and the exercise price of the stock option. Stock Options The fair value of each option grant is estimated on the date of the grant using the Black-Scholes option-pricing model with the following assumptions: • Volatility is based on peer group volatility because the Company does not have a sufficient trading history. • Expected life represents the period of time that the option is expected to be outstanding, taking into account the contractual term, and the vesting period. • Expected dividend yield is based on the Company's history and expectation of dividend payouts. • The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for a period equivalent to the expected life of the option. The Company made the following awards of options to purchase shares of common stock during the nine months ended September 30, 2018 : Options granted 214,500 Vesting period (years) 5 Term (years) 10 Fair value calculation assumptions: Expected volatility 25.40%-26.47% Expected life (years) 6.5 Expected dividend yield 3.21%-3.47% Risk free interest rate 2.39%-2.80% Weighted average grant date fair value $4.12-$4.13 A summary of the status of the Company's stock option grants for the nine months ended September 30, 2018 , is presented in the table below: Stock Option Awards Weighted Average Exercise Price Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at December 31, 2017 2,684,650 $ 14.70 Granted 214,500 21.04 Forfeited (79,120 ) 14.31 Exercised (60,500 ) 14.10 426,000 Outstanding at September 30, 2018 2,759,530 $ 15.21 7.42 $ 24,522,000 Exercisable at September 30, 2018 963,080 $ 14.42 7.14 $ 9,326,000 Unrecognized compensation cost inclusive of directors' options at September 30, 2018 $ 5,769,000 Weighted average remaining recognition period (years) 2.69 For the three months ended September 30, 2018 and 2017 , share-based compensation expense applicable to the stock options was $589,000 and $ 574,000 , respectively, and the recognized tax benefit related to this expense was $113,000 and $159,000 , respectively. For the nine months ended September 30, 2018 and 2017 , share-based compensation expense applicable to the stock options was $1.7 million and $1.8 million , respectively, and the recognized tax benefit related to this expense was $332,000 and $475,000 . Restricted Stock Shares issued upon vesting may be either authorized but unissued shares or reacquired shares held by the Company. Any shares not issued because vesting requirements are not met will again be available for issuance under the plan. The fair market value of shares awarded, based on the market price at the date of grant, is recorded as unearned compensation and amortized over the applicable vesting period. Of the restricted shares granted to date, 40,000 are performance based, of which 12,000 have vested, 4,000 have been forfeited and 24,000 remain unvested. There were 2,000 performance shares forfeited during the nine months ended September 30, 2018 . The following table presents the activity in non-vested stock awards under the Equity Plan for the nine months ended September 30, 2018 : Outstanding Restricted Stock Awards Weighted Average Grant Price Nonvested stock awards at December 31, 2017 730,420 $ 15.11 Granted 59,300 21.10 Vested (50,882 ) 17.09 Forfeited (24,890 ) 14.31 Nonvested stock awards at September 30, 2018 713,948 $ 15.50 Unrecognized compensation cost inclusive of directors' awards at September 30, 2018 $8,211,000 Weighted average remaining recognition period (years) 2.70 For the three months ended September 30, 2018 and 2017 , share-based compensation expense applicable to restricted stock awards was $ 825,000 and $789,000 , respectively, and the recognized tax benefit related to this expense was $232,000 and $322,000 , respectively. For both the nine months ended September 30, 2018 and 2017 , share-based compensation expense applicable to restricted stock awards in both years was $2.4 million , and the recognized tax benefit related to this expense was $674,000 and $962,000 , respectively.

Basis of Presentation and Con_2

Basis of Presentation and Consolidation (Policies)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim consolidated financial statements include the accounts of Blue Hills Bancorp, Inc. (the "Company"), its wholly-owned subsidiaries, Blue Hills Funding Corporation and Blue Hills Bank (the "Bank"), the principal operating entity, and the Bank's wholly-owned subsidiaries, B.H. Security Corporation, HP Security Corporation and 1196 Corporation, which are Massachusetts security corporations, and Nantucket Property Acquisition Company LLC, the Bank's subsidiary that holds other real estate owned. All significant intercompany balances and transactions have been eliminated in consolidation. The unaudited consolidated financial statements of the Company presented herein have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) for interim financial information and pursuant to the rules of the Securities and Exchange Commission ("SEC") for quarterly reports on Form 10-Q and Article 10 of Regulation S-X and do not include all of the information and note disclosures required by GAAP for a complete set of financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) and disclosures necessary for the fair presentation of the accompanying consolidated financial statements have been included. Interim results are not necessarily reflective of the results of the year. The accompanying unaudited financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2017, included in the Company's annual report on Form 10-K. 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 sheet and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the determination of the allowance for loan losses and the valuation of deferred tax assets.
Loan policies	Loan policies The Company has historically granted mortgage and consumer loans to its customers and a substantial portion of the loan portfolio consists of mortgage loans in communities including and near the locations of its banking offices. The ability of the Company’s debtors to honor their contracts is dependent upon the real estate and general economic conditions in these areas. The Company’s loan portfolio includes 1-4 family residential real estate, home equity, commercial real estate, construction, commercial business, and consumer segments. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off generally are reported at their outstanding unpaid principal balances adjusted for the allowance for loan losses, charge-offs, deferred origination fees and costs, and discounts on purchased loans. Interest income is accrued on the unpaid principal balance. Deferred loan origination fees/costs and discounts on purchased loans are recognized as an adjustment of the related loan yield using the interest method. It is the policy of the Company to discontinue the accrual of interest on loans past due in excess of 90 days, unless the loan is well-secured and in the process of collection. Accrual may be discontinued sooner when in the judgment of management, the ultimate collectability of the principal or interest becomes doubtful. Upon discontinuance of accrual, all interest previously accrued is reversed against interest income. Past due status is based on contractual terms of the loan. The interest on non-accrual loans is accounted for on the cash-basis until qualifying for return to accrual. Loans are returned to accrual status when all the principal and interest amounts contractually due have been current for six consecutive months and future payments are reasonably assured.
Allowance for Loan Losses	Allowance for loan losses The allowance for loan losses is based on the size and the composition of the loan portfolio, delinquency levels, loss experience, economic conditions and other factors related to the collectability of the loan portfolio. Loss experience is updated at least quarterly with consideration given to unusual circumstances in the portfolio. Loan losses are charged against the allowance when management believes the uncollectability of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is evaluated regularly by management and reflects consideration of all significant factors that affect the collectability of the loan portfolio. The evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. It is the intention of management to maintain an allowance that is prudently commensurate with the growth in the loan portfolio. The allowance consists of general and allocated components, as further described below. General component The general component of the allowance for loan losses is based on a combination of the Company's own loss history and an extrapolated historical loss experience based on FDIC data for depository institutions with assets of one billion to five billion dollars dating back to 2010, adjusted for qualitative and environmental factors including changes to lending policies and procedures, economic and business conditions, portfolio characteristics, staff experience, problem loan trends, collateral values, concentrations and the competitive, legal and regulatory environment. The qualitative factors are determined based on the various risk characteristics of each loan segment. Risk characteristics relevant to each portfolio segment are as follows: Residential real estate - The Company does not generally originate loans with a loan-to-value ratio greater than 80 percent and does not generally grant loans that would be classified as subprime upon origination. When the Company does extend credit either on a first- or second-lien basis at a loan-to-value ratio greater than 80 percent , such loans are supported by either mortgage insurance or state guarantee programs. All loans in this segment are collateralized by owner-occupied, 1-4 family residential real estate and repayment is dependent on the credit quality of the individual borrower. The health of the national and state economy, including unemployment rates and housing prices, will have an effect on the credit quality of loans in this segment. Home equity - Loans in this segment are generally secured by first or second liens on residential real estate. Repayment is dependent on the credit quality of the individual borrower. The Company evaluates each loan application based on factors including the borrower’s credit score, income, length of employment, and other factors to establish the creditworthiness of the borrower. Commercial real estate - Loans in this segment include investment real estate and are generally secured by assignments of leases, real estate collateral and owner-occupied properties. In cases where there is a concentration of exposure to a single large tenant, underwriting standards include analysis of the tenant’s ability to support lease payments over the duration of the loan. The underlying cash flows generated by the properties may be adversely impacted by a downturn in the economy due to increased vacancy rates, which in turn can have an effect on the credit quality in this segment. Payments on loans secured by income-producing properties often depend on the successful operation and management of the properties. Management continually monitors the cash flows of these loans. Construction - Loans in this segment primarily include real estate development loans for which payment is derived from permanent financing or sale of the property. Credit risk is affected by cost overruns, time to sell at an adequate price, and market conditions. Commercial business - Loans in this segment are generally secured by business assets, including accounts receivable, inventory, real estate and intangible assets. Strict underwriting standards include considerations of the borrower’s ability to support the debt service requirements from the underlying historical and projected cash flows of the business, collateral values, the borrower’s credit history and the ultimate collectability of the de bt. Economic conditions, real estate values, commodity prices, unemployment trends and other factors will affect the credit quality of loans in these segments. Consumer - Loans in this segment primarily include used classic and collector automobile loans. A significant portion of the used automobile loan portfolio is comprised of geographically diverse loans originated by and purchased from a third party, who also provides collection services and shares equally in any losses incurred. Allocated component The allocated component relates to loans that are considered impaired. Impairment is measured by either the present value of expected future cash flows discounted at the loan’s effective interest rate or the fair value of the collateral if the loan is collateral dependent. An allowance is established when the discounted cash flows or collateral value of the impaired loan is lower than the carrying value of that loan. A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Management reviews all loan types for individual impairment. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. The Company periodically may agree to modify the contractual terms of loans. When a loan is modified and a concession is made to a borrower experiencing financial difficulty, the modification is considered a troubled debt restructuring (“TDR”). All TDRs are initially classified as impaired and generally remain impaired for the remaining life of the loan. The impaired classification may be removed if the borrower demonstrates compliance with the modified terms and the restructuring agreement specifies an interest rate equal to that which would be provided to a borrower with similar credit at the time of restructuring.
Recent Accounting Standards Updates	Accounting Standards Adopted in the Period In August 2018, the FASB issued ASU 2018-14, " Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans." The guidance modifies disclosure requirements for defined benefit plans. This guidance is effective for fiscal years ending after December 15, 2020, and early adoption is permitted. The Company is evaluating the provisions of this Update and the impact to the consolidated financial statements upon adoptions is not expected to be material. In August 2018, the FASB issued ASU 2018-13, “ Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement”, which adds disclosure requirements to Topic 820 for the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The Update is effective for all entities for fiscal years beginning after December 15, 2019, including interim periods therein. Early adoption is permitted for any eliminated or modified disclosures upon issuance of this Update. The Company is evaluating the provisions of this Update and the impact to the consolidated financial statements upon adoptions is not expected to be material. In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . The purpose of this Update is to allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The Company adopted the Update on January 1, 2018. The effect of applying the provisions of this Update resulted in an increase to retained earnings and a corresponding decrease in accumulated other comprehensive loss in the amount of $279,000 . Effective January 1, 2018, the Company adopted ASU 2016-01, Financial Instruments – Overall, (Subtopic 825-10) . The amendments in this Update address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. Targeted improvements to generally accepted accounting principles include the requirement for 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 and the elimination of the requirement for public business entities to disclose the methods and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost. The Update also requires Companies to utilize an "exit price" fair value methodology when measuring the fair value of financial instruments. The cumulative effect of applying the provisions of this Update resulted in an increase to retained earnings and a corresponding decrease to accumulated other comprehensive loss in the amount of $173,000 . Effective January 1, 2018, the Company adopted ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory . The amendments in this Update require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The impact to the consolidated financial statements upon adopting was not material. Effective January 1, 2018, the Company adopted ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash . The amendments in this Update require that in the statement of cash flows, amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts. The impact to the consolidated financial statements upon adopting was not material. Effective January 1, 2018, the Company adopted ASU 2014-09, Revenue from Contracts with Customers . This Update provides a revenue recognition framework for any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets unless those contracts are within the scope of other accounting standards. The Company's revenue relates principally to financial instruments, which are explicitly excluded from the scope of the new guidance. The Company adopted this Update on January 1, 2018 and the impact to the consolidated financial statements upon adopting was not material. Effective January 1, 2018, the Company adopted ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting which amends the scope of modification accounting for share-based payment arrangements. The Update provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting. Specifically, an entity would not apply modification accounting if the fair value, vesting conditions, and classification of the awards are the same immediately before and after the modification. The Update should be applied prospectively to awards modified on or after the effective date. The impact to the consolidated financial statements upon adopting was not material. Recently Issued In July 2018, the FASB issued ASU 2018-10, Codification Improvements to Topic 842, Leases and ASU 2018-11, Leases . The guidance provides clarification on the application of ASU 2016-02, specifically on certain narrow aspects of the guidance issued under ASU 2016-02, including comparative reporting requirements for initial adoption and, for lessors only, separating lease and non-lease components in a contract and allocating the consideration in the contract to the separate components. For entities that have not adopted ASU 2016-02 before the issuance of these updates, the amendments in this guidance are the same as the effective date and transition requirements in ASU 2016-02. The adoption of this Update is not expected to have an impact on the Company’s consolidated financial statements. Future Application of Accounting Pronouncements Previously Issued In June 2018 the FASB issued ASU 2018-07 Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. The Updates expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. An entity should apply the requirements of Topic 718 to nonemployee awards except for specific guidance on inputs to an option pricing model and the attribution of cost (that is, the period of time over which share-based payment awards vest and the pattern of cost recognition over that period). The Update is effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The Company does not anticipate the adoption of ASU 2018-07 will have a material impact on its consolidated financial statements. In March 2018, the FASB issued ASU 2018-04, Investments-Debt Securities (Topic 320) and Regulated Operations (Topic 980) . Amendments to SEC paragraph Pursuant to SEC Staff Accounting Bulletin No. 177 and SEC Release No 33-9273, the amendment of ASU 2018-04 adds, amends and supersedes variance paragraphs that contain SEC guidance in ASC 320, Investments-Debt Securities and ASC 980, Regulated Operations. The Company does not anticipate the adoption of ASU 2018-04 will have a material impact on its consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities . The purpose of this Update is to better align a company’s financial reporting for hedging activities with the economic objectives of those activities. This Update is effective for public business entities for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period permitted. The Update requires a modified retrospective transition method in which the Company will recognize the cumulative effect of the change on the opening balance of each affected component of equity in the statement of financial position as of the date of adoption. While the Company continues to assess all potential impacts of the standard, the Company currently expects the adoption to have an immaterial impact on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) . This Update is intended to improve financial reporting about leasing transactions and the key provision impacting the Company is the requirement for a lessee to record a right-to-use asset and a liability representing the obligation to make lease payments for long-term operating leases. Additionally, the Update includes additional quantitative and qualitative disclosures required by lessees and lessors to help users better understand the amount, timing, and uncertainty of cash flows arising from leases. This Update is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that entities may elect to apply as well as transition guidance specific to nonstandard leasing transactions. The Company's assets and liabilities will increase based on the present value of remaining lease payments for leases in place at the adoption date; however, this is not expected to be material to the Company's results of operations or financial position. Future lease commitments as of at September 30, 2018 amounted to $19.9 million . In June, 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which removes the thresholds that companies apply to measure credit losses on financial instruments measured at amortized cost, such as loans, receivables, and held-to-maturity debt securities. Under current U.S. GAAP, companies generally recognize credit losses when it is probable that the loss has been incurred. The revised guidance will remove previously established recognition thresholds based on probability, and will require companies to recognize an allowance for credit losses for the difference between the amortized cost basis of a financial instrument and the net amount that the company expects to collect over the instrument’s contractual life. ASU 2016-13 also amends the credit loss measurement guidance for available-for-sale debt securities and will require that credit losses be recorded through an allowance for credit losses. Additionally, this Update may reduce the carrying value of the Company's held-to-maturity investment securities as it will require an allowance on the expected losses over the life of these securities to be recorded upon adoption. The ASU is effective for public business entities fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. Any increase in our allowance for loan losses or expenses may have a material adverse effect on our financial condition and results of operations. The Company is actively working through the provisions of the Update. Management has established a steering committee which has identified the methodologies and the additional data requirements necessary to implement the Update and has engaged a third-party software service provider to assist in the Company's implementation.

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities	December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available for Sale: Marketable equity securities $ 9,437 $ 755 $ (472 ) $ 9,720 Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ 30,673 $ — $ (894 ) $ 29,779 Government-sponsored mortgage-backed and collateralized mortgage obligations 244,668 30 (3,437 ) 241,261 SBA asset-backed securities 28,375 28 (329 ) 28,074 Total securities held to maturity $ 303,716 $ 58 $ (4,660 ) $ 299,114
Held-to-maturity Securities	December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available for Sale: Marketable equity securities $ 9,437 $ 755 $ (472 ) $ 9,720 Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ 30,673 $ — $ (894 ) $ 29,779 Government-sponsored mortgage-backed and collateralized mortgage obligations 244,668 30 (3,437 ) 241,261 SBA asset-backed securities 28,375 28 (329 ) 28,074 Total securities held to maturity $ 303,716 $ 58 $ (4,660 ) $ 299,114 The amortized cost and estimated fair value of securities available for sale and securities held to maturity, with gross unrealized gains and losses, follows: September 30, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ 30,688 $ — $ (1,358 ) $ 29,330 Government-sponsored mortgage-backed and collateralized mortgage obligations 246,624 6 (9,668 ) 236,962 SBA asset-backed securities 28,623 32 (999 ) 27,656 Total securities held to maturity $ 305,935 $ 38 $ (12,025 ) $ 293,948
Investments Classified by Contractual Maturity Date	The amortized cost and estimated fair value of debt securities by contractual maturity at September 30, 2018 are included in the following table. Expected maturities will differ from contractual maturities because the issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Based on expected maturities, the mortgage and asset-backed securities and collateralized mortgage obligations, included below, have a 4.0 year weighted average duration. Amortized Cost Fair Value (In thousands) Within 1 year $ 1,098 $ 1,088 After 1 year through 5 years 23,040 22,124 After 5 years through 10 years 6,550 6,118 30,688 29,330 Mortgage and asset-backed securities and collateralized mortgage obligations 275,247 264,618 $ 305,935 $ 293,948
Unrealized Gain (Loss) and Fair Value of Investments - Available-for-sale Securities	December 31, 2017 Less Than Twelve Months More Than Twelve Months Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (In thousands) Securities Available for Sale: Temporarily impaired marketable equity securities $ (449 ) $ 4,310 $ (23 ) $ 443
Unrealized Gain (Loss) and Fair Value of Investments - Held-to-maturity Securities	Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ (109 ) $ 8,521 $ (785 ) $ 21,258 Government-sponsored mortgage-backed and collateralized mortgage obligations (1,563 ) 119,782 (1,874 ) 111,712 SBA asset-backed securities (34 ) 9,897 (295 ) 11,423 Total temporarily impaired securities held to maturity $ (1,706 ) $ 138,200 $ (2,954 ) $ 144,393 Information pertaining to securities with gross unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous loss position, follows: September 30, 2018 Less Than Twelve Months More Than Twelve Months Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (In thousands) Securities Held to Maturity: Debt securities: Government-sponsored enterprises $ (65 ) $ 3,031 $ (1,293 ) $ 26,299 Government-sponsored mortgage-backed and collateralized mortgage obligations (1,608 ) 61,656 (8,060 ) 174,794 SBA asset-backed securities (194 ) 6,160 (805 ) 18,486 Total temporarily impaired securities held to maturity $ (1,867 ) $ 70,847 $ (10,158 ) $ 219,579

Loans and The Allowance for L_2

Loans and The Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2018
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	A summary of the balances of loans follows: September 30, December 31, 2018 2017 (In thousands) Real estate: 1-4 family residential $ 1,003,731 $ 922,627 Home equity 70,071 80,662 Commercial real estate 853,899 834,264 Construction 75,390 91,050 2,003,091 1,928,603 Commercial business 283,200 253,509 Consumer 16,889 21,698 Total loans 2,303,180 2,203,810 Allowance for loan losses (19,920 ) (20,877 ) Discount and fair value adjustments on purchased loans (1,126 ) (1,477 ) Deferred loan costs and fees, net 4,662 4,691 Loans, net $ 2,286,796 $ 2,186,147
Activity in Allowance for Loan Losses	Activity in the allowance for loan losses for the three and nine months ended September 30, 2018 and 2017 , by loan segment, follows: 1-4 Family Home Commercial Construction Commercial Consumer Total (In thousands) Three Months Ended September 30, 2018 Allowance at June 30, 2018 $ 5,372 $ 603 $ 8,992 $ 1,479 $ 3,389 $ 290 $ 20,125 Provision (credit) for loan losses (8 ) (27 ) 6 (323 ) 178 (8 ) (182 ) Loans charged-off — — — — — (23 ) (23 ) Recoveries — — — — — — — Allowance at September 30, 2018 $ 5,364 $ 576 $ 8,998 $ 1,156 $ 3,567 $ 259 $ 19,920 Three Months Ended September 30, 2017 Allowance at June 30, 2017 $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ 19,917 Provision (credit) for loan losses (3 ) 61 (153 ) 169 159 9 242 Loans charged-off — — — — — (36 ) (36 ) Recoveries 125 — — — — — 125 Allowance at September 30, 2017 $ 5,095 $ 670 $ 8,834 $ 1,779 $ 3,511 $ 359 $ 20,248 Nine Months Ended September 30, 2018 Allowance at December 31, 2017 $ 5,076 $ 699 $ 9,584 $ 1,708 $ 3,473 $ 337 $ 20,877 Provision (credit) for loan losses 288 (123 ) (392 ) (552 ) 261 (23 ) (541 ) Loans charged-off — — (194 ) — (178 ) (63 ) (435 ) Recoveries — — — — 11 8 19 Allowance at September 30, 2018 $ 5,364 $ 576 $ 8,998 $ 1,156 $ 3,567 $ 259 $ 19,920 Nine Months Ended September 30, 2017 Allowance at December 31, 2016 $ 4,846 $ 537 $ 8,374 $ 1,353 $ 3,206 $ 434 $ 18,750 Provision (credit) for loan losses 102 133 460 426 296 — 1,417 Loans charged-off (52 ) — — — — (75 ) (127 ) Recoveries 199 — — — 9 — 208 Allowance at September 30, 2017 $ 5,095 $ 670 $ 8,834 $ 1,779 $ 3,511 $ 359 $ 20,248
Allowance for Credit Losses on Financing Receivables	Additional information pertaining to the allowance for loan losses at September 30, 2018 and December 31, 2017 is as follows: 1-4 Family Home Commercial Construction Commercial Consumer Total (In thousands) September 30, 2018 Allowance related to impaired loans $ 45 $ — $ — $ — $ — $ — $ 45 Allowance related to non-impaired loans 5,319 576 8,998 1,156 3,567 259 19,875 Total allowance for loan losses $ 5,364 $ 576 $ 8,998 $ 1,156 $ 3,567 $ 259 $ 19,920 Impaired loans $ 6,801 $ 1,814 $ 3,386 $ — $ 163 $ 99 $ 12,263 Non-impaired loans 996,930 68,257 850,513 75,390 283,037 16,790 2,290,917 Total loans $ 1,003,731 $ 70,071 $ 853,899 $ 75,390 $ 283,200 $ 16,889 $ 2,303,180 December 31, 2017 Allowance related to impaired loans $ 80 $ — $ — $ — $ — $ 1 $ 81 Allowance related to non-impaired loans 4,996 699 9,584 1,708 3,473 336 20,796 Total allowance for loan losses $ 5,076 $ 699 $ 9,584 $ 1,708 $ 3,473 $ 337 $ 20,877 Impaired loans $ 5,949 $ 1,387 $ 4,744 $ — $ — $ 202 $ 12,282 Non-impaired loans 916,678 79,275 829,520 91,050 253,509 21,496 2,191,528 Total loans $ 922,627 $ 80,662 $ 834,264 $ 91,050 $ 253,509 $ 21,698 $ 2,203,810
Past Due Financing Receivables	The following is a summary of past due and non-accrual loans, by loan class, at September 30, 2018 and December 31, 2017 : 30-59 Days Past Due 60-89 Days Past Due Past Due 90 Days or More Total Past Due Loans on Non-accrual (In thousands) September 30, 2018 Real estate: 1-4 family residential $ 970 $ 664 $ 1,607 $ 3,241 $ 6,339 Home equity 483 692 434 1,609 1,814 Commercial real estate — — — — 3,386 Commercial business — — — — 163 Consumer 95 — 25 120 82 Total $ 1,548 $ 1,356 $ 2,066 $ 4,970 $ 11,784 December 31, 2017 Real estate: 1-4 family residential $ 381 $ 348 $ 2,184 $ 2,913 $ 5,190 Home equity 509 13 656 1,178 1,387 Commercial real estate — — 3,893 3,893 4,744 Consumer 107 7 92 206 202 Total $ 997 $ 368 $ 6,825 $ 8,190 $ 11,523
Impaired Financing Receivables	The following tables set forth information regarding average balances and interest income recognized (the majority of which is on a cash basis) on impaired loans by class, for the periods indicated: Average Recorded Investment Interest Income Recognized Three Months Ended September 30, 2018 (In thousands) Real estate: 1-4 family residential $ 6,331 $ 75 Home equity 2,019 20 Commercial real estate 2,850 30 Commercial business 171 6 Consumer 97 1 Total $ 11,468 $ 132 Three Months Ended September 30, 2017 Real estate: 1-4 family residential $ 6,041 $ 60 Home equity 1,198 6 Commercial real estate 4,933 172 Commercial business 89 — Consumer 340 2 Total $ 12,601 $ 240 Nine Months Ended September 30, 2018 Real estate: 1-4 family residential $ 6,159 $ 225 Home equity 1,688 65 Commercial real estate 3,210 76 Commercial business 162 14 Consumer 122 4 Total $ 11,341 $ 384 Nine Months Ended September 30, 2017 Real estate: 1-4 family residential $ 6,330 $ 220 Home equity 1,234 35 Commercial real estate 3,970 207 Commercial business 161 5 Consumer 251 7 Total $ 11,946 $ 474 The following is a summary of information pertaining to impaired loans by loan class at the dates indicated: Recorded Investment Unpaid Principal Balance Related Allowance September 30, 2018 (In thousands) Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 5,447 $ 5,844 $ — Home equity 1,814 1,944 — Commercial real estate 3,386 3,543 — Commercial business 163 314 — Consumer 99 113 — Total 10,909 11,758 — Impaired loans with a valuation allowance: 1-4 family residential 1,354 1,354 45 Total impaired loans $ 12,263 $ 13,112 $ 45 December 31, 2017 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,501 $ 4,897 $ — Home equity 1,387 1,523 — Commercial real estate 4,744 5,206 — Commercial business — 11 — Consumer 191 243 — Total 10,823 11,880 — Impaired loans with a valuation allowance: Real estate: 1-4 family residential 1,448 1,448 80 Consumer 11 11 1 Total 1,459 1,459 81 Total impaired loans $ 12,282 $ 13,339 $ 81
Troubled Debt Restructurings	There were no troubled debt restructurings entered into during the three months ended September 30, 2018. Troubled debt restructurings entered into during the nine months ended September 30, 2018 are as follows: Nine Months Ended September 30, 2018 Number of contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Real estate: 1-4 family residential 3 $ 469 $ 475 Home equity 1 359 359 Commercial real estate 1 1,563 1,563 Total 5 $ 2,391 $ 2,397
Financing Receivable Credit Quality Indicators	The following tables present the Company’s loans by risk rating at September 30, 2018 and December 31, 2017 : 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Total Loans (In thousands) September 30, 2018 Loans rated 1 - 6 $ 994 $ 328 $ 841,437 $ 75,390 $ 266,574 $ 3 $ 1,184,726 Loans rated 7 3,694 1,853 5,316 — 15,534 82 26,479 Loans rated 8 2,750 — 7,146 — 1,092 16 11,004 Loans rated 9 242 — — — — — 242 Loans rated 10 — — — — — — — Loans not rated 996,051 67,890 — — — 16,788 1,080,729 $ 1,003,731 $ 70,071 $ 853,899 $ 75,390 $ 283,200 $ 16,889 $ 2,303,180 December 31, 2017 Loans rated 1 - 6 $ 1,022 $ 270 $ 821,815 $ 91,050 $ 252,765 $ 3 $ 1,166,925 Loans rated 7 2,848 1,523 4,660 — 744 121 9,896 Loans rated 8 2,566 — 7,789 — — — 10,355 Loans rated 9 250 — — — — — 250 Loans rated 10 — — — — — — — Loans not rated 915,941 78,869 — — — 21,574 1,016,384 $ 922,627 $ 80,662 $ 834,264 $ 91,050 $ 253,509 $ 21,698 $ 2,203,810

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Interest Rate Derivatives	The table below presents information about derivative financial instruments not designated as hedging instruments at September 30, 2018 and December 31, 2017 . Derivative Gains Derivative Losses Notional Amount Fair Value Notional Amount Fair Value (In thousands) September 30, 2018 Economic hedges: Commercial loan level interest rate swap agreements $ 629,078 $ 18,458 $ 629,078 $ 18,458 Other contracts 37,212 35 46,507 26 Total derivatives $ 666,290 $ 18,493 $ 675,585 $ 18,484 December 31, 2017 Economic hedges: Commercial loan level interest rate swap agreements $ 582,388 $ 8,741 $ 582,388 $ 8,741 Other contracts 27,689 25 54,293 44 Total derivatives $ 610,077 $ 8,766 $ 636,681 $ 8,785
Summary of Fair Value and Location of Mortgage Loan and Forward Loan Sale Commitments	The fair value of such commitments as of September 30, 2018 and December 31, 2017 are outlined below: Assets Liabilities Balance sheet location Fair Value Balance sheet location Fair Value (In thousands) September 30, 2018 Derivative loan commitments: Mortgage loan commitments best efforts Other assets $ 73 Other liabilities $ 6 Mortgage loan commitments mandatory delivery Other assets 160 Other liabilities 3 Total mortgage derivative commitments $ 233 $ 9 Forward loan sale commitments: Forward loan sale commitments best efforts Other assets $ 8 Other liabilities $ 11 Forward loan sale commitments mandatory delivery Other assets 53 Other liabilities 9 Total forward loan sale commitments $ 61 $ 20 Total $ 294 $ 29 December 31, 2017 Derivative loan commitments: Mortgage loan commitments best efforts Other assets $ 210 Other liabilities $ 36 Total mortgage derivative commitments $ 210 $ 36 Forward loan sale commitments: Forward loan sale commitments best efforts Other assets $ 22 Other liabilities $ 69 Total forward loan sale commitments $ 22 $ 69 Total $ 232 $ 105

Deposits (Tables)

Deposits (Tables)	9 Months Ended
	Sep. 30, 2018
Banking and Thrift [Abstract]
Schedule of Deposit Balances	A summary of deposit balances, by type, is as follows: September 30, December 31, 2018 2017 (In thousands) NOW and demand $ 415,993 $ 381,316 Regular savings 206,726 221,004 Money market 620,529 646,603 Brokered money market 80,143 92,798 Total non-certificate accounts 1,323,391 1,341,721 Term certificates of $250,000 or more 179,926 134,649 Term certificates less than $250,000 382,684 313,733 Brokered term certificates 280,006 249,766 Total term certificate accounts 842,616 698,148 Total deposits $ 2,166,007 $ 2,039,869
Schedule of Contractual Maturities of Deposits and Weighted Average Rate	At September 30, 2018 , the scheduled maturities of term certificate accounts, including brokered deposits, are as follows: Amount Weighted Average Rate (Dollars in thousands) Within 1 year $ 515,442 1.79 % 1-2 years 201,257 1.98 2-3 years 92,326 2.49 3-4 years 28,191 2.07 4 years and beyond 5,400 1.67 $ 842,616 1.92 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis are summarized below: Level 1 Level 2 Level 3 Total Fair Value (In thousands) September 30, 2018 Assets Equity securities, at fair value $ 5,270 $ — $ — $ 5,270 Derivative assets: Interest rate swap agreements — 18,493 — 18,493 Forward loan sale commitments - best efforts — — 8 8 Forward loan sale commitments - mandatory delivery — — 53 53 Mortgage loan commitments - best efforts — — 73 73 Mortgage loan commitments - mandatory delivery — — 160 160 Total assets $ 5,270 $ 18,493 $ 294 $ 24,057 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 18,484 $ — $ 18,484 Forward loan sale commitments - best efforts — — 11 11 Forward loan sale commitments - mandatory delivery — — 9 9 Mortgage loan commitments - best efforts — — 6 6 Mortgage loan commitments - mandatory delivery — — 3 3 Total liabilities $ — $ 18,484 $ 29 $ 18,513 December 31, 2017 Assets Securities available for sale: Marketable equity securities $ 9,720 $ — $ — $ 9,720 Derivative assets: Interest rate swap agreements — 8,766 — 8,766 Forward loan sale commitments - best efforts — — 22 22 Mortgage loan commitments - best efforts — — 210 210 Total assets $ 9,720 $ 8,766 $ 232 $ 18,718 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 8,785 $ — $ 8,785 Forward loan sale commitments - best efforts — — 69 69 Mortgage loan commitments - best efforts — — 36 36 Total liabilities $ — $ 8,785 $ 105 $ 8,890
Fair Value Measurements, Nonrecurring	The following table summarizes the fair value hierarchy applicable to assets measured at fair value on a non-recurring basis: September 30, 2018 December 31, 2017 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 (In thousands) Impaired loans $ — $ — $ 1,517 $ — $ — $ 2,214 Other real estate owned — — 3,649 — — — $ — $ — $ 5,166 $ — $ — $ 2,214 The following table summarizes the total gains (losses) on assets measured at fair value on a non-recurring basis for the three and nine months ended September 30, 2018 and 2017 . Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 (In thousands) Impaired loans $ 4 $ 11 $ (346 ) $ 2
Fair Value, by Balance Sheet Grouping	The estimated fair values, and related carrying amounts, of the Company’s financial instruments are as follows. Certain financial instruments and all nonfinancial instruments are exempt from disclosure requirements. Accordingly, the aggregate fair value amounts presented herein do not represent the underlying fair value of the Company. Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) September 30, 2018 Financial assets: Cash and cash equivalents $ 47,749 $ 47,749 $ — $ — $ 47,749 Equity securities at fair value 5,270 5,270 — — 5,270 Securities held to maturity 305,935 — 293,948 — 293,948 Federal Home Loan Bank stock 11,815 — — 11,815 11,815 Loans and loans held for sale, net 2,291,831 — — 2,267,797 2,267,797 Accrued interest receivable 7,143 — — 7,143 7,143 Financial liabilities: Deposits 2,166,007 — — 2,160,039 2,160,039 Borrowings 178,000 — 176,902 — 176,902 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 18,493 — 18,493 — 18,493 Forward loan sale commitments - best efforts 8 — — 8 8 Forward loan sale commitments - mandatory delivery 53 — — 53 53 Mortgage loan commitments - best efforts 73 — — 73 73 Mortgage loan commitments-mandatory delivery 160 — — 160 160 Derivative liabilities: Interest rate swap agreements 18,484 — 18,484 — 18,484 Forward loan sale commitments - best efforts 11 — — 11 11 Forward loan sale commitments - mandatory delivery 9 — — 9 9 Mortgage loan commitments - best efforts 6 — — 6 6 Mortgage loan commitments - mandatory delivery 3 — — 3 3 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) December 31, 2017 Financial assets: Cash and cash equivalents $ 46,167 $ 46,167 $ — $ — $ 46,167 Securities available for sale 9,720 9,720 — — 9,720 Securities held to maturity 303,716 — 299,114 — 299,114 Federal Home Loan Bank stock 12,105 — — 12,105 12,105 Loans and loans held for sale 2,195,139 — — 2,174,871 2,174,871 Accrued interest receivable 6,438 — — 6,438 6,438 Financial liabilities: Deposits 2,039,869 — — 2,036,150 2,036,150 Borrowings 205,000 — 203,913 — 203,913 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 8,766 — 8,766 — 8,766 Forward loan sale commitments - best efforts 22 — — 22 22 Mortgage loan commitments - best efforts 210 — — 210 210 Derivative liabilities: Interest rate swap agreements 8,785 — 8,785 — 8,785 Forward loan sale commitments - best efforts 69 — — 69 69 Mortgage loan commitments - best efforts 36 — — 36 36

Comprehensive Income (Tables)

Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive loss, included in stockholders' equity, are as follows: September 30, December 31, 2018 2017 (In thousands) Securities available for sale: Net unrealized gain $ — $ 283 Tax effect — (140 ) Net-of-tax amount — 143 Securities held to maturity: Net unrealized gain on transferred securities 187 250 Tax effect (15 ) (66 ) Net-of-tax amount 172 184 Defined benefit pension plan: Unrecognized net actuarial loss (2,495 ) (2,694 ) Tax effect 514 914 Net-of-tax amount (1,981 ) (1,780 ) $ (1,809 ) $ (1,453 )

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The Company's and the Bank's actual capital amounts and ratios as of September 30, 2018 and December 31, 2017 are also presented in the following table. Actual Minimum Capital Requirement Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) Blue Hills Bancorp, Inc.: September 30, 2018 Total capital (to risk weighted assets) $ 415,901 18.3 % $ 182,234 8.0 % $ 227,793 10.0 % Tier 1 capital (to risk weighted assets) 395,981 17.4 136,676 6.0 182,234 8.0 Common equity Tier 1 (to risk weighted assets) 395,981 17.4 102,507 4.5 148,065 6.5 Tier 1 capital (to average assets) 395,981 14.4 109,770 4.0 137,212 5.0 December 31, 2017 Total capital (to risk weighted assets) $ 410,088 19.7 % $ 166,635 8.0 % $ 208,294 10.0 % Tier 1 capital (to risk weighted assets) 389,211 18.7 124,977 6.0 166,635 8.0 Common equity Tier 1 (to risk weighted assets) 389,211 18.7 93,732 4.5 135,391 6.5 Tier 1 capital (to average assets) 389,211 14.9 104,278 4.0 130,348 5.0 Blue Hills Bank: September 30, 2018 Total capital (to risk weighted assets) $ 365,926 16.1 % $ 182,059 8.0 % $ 227,574 10.0 % Tier 1 capital (to risk weighted assets) 346,006 15.2 136,544 6.0 182,059 8.0 Common equity Tier 1 (to risk weighted assets) 346,006 15.2 102,408 4.5 147,923 6.5 Tier 1 capital (to average assets) 346,006 12.6 109,664 4.0 137,080 5.0 December 31, 2017 Total capital (to risk weighted assets) $ 341,175 16.4 % $ 166,391 8.0 % $ 207,988 10.0 % Tier 1 capital (to risk weighted assets) 320,298 15.4 124,793 6.0 166,391 8.0 Common equity Tier 1 (to risk weighted assets) 320,298 15.4 93,595 4.5 135,192 6.5 Tier 1 capital (to average assets) 320,298 12.3 104,137 4.0 130,171 5.0

Employee Stock Ownership Plan (

Employee Stock Ownership Plan (Tables)	9 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Employee Stock Ownership Plan (ESOP) Disclosures	Shares held by the ESOP include the following: September 30, 2018 December 31, 2017 Allocated 291,617 219,860 Committed to be allocated 56,778 75,912 Unallocated 1,916,919 1,973,699 2,265,314 2,269,471

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Three Months Ended September 30, 2018 2017 (In thousands, except share amounts) Net income applicable to common stock $ 5,789 $ 3,841 Average number of common shares outstanding 26,894,607 26,865,148 Less: Average unallocated ESOP shares (1,926,486 ) (2,002,397 ) Less: Average unvested restricted stock awards (711,219 ) (889,635 ) Average number of common shares outstanding used to calculate basic earnings per common share 24,256,902 23,973,116 Effect of dilutive stock options 664,345 240,806 Effect of dilutive unvested restricted stock awards 321,490 296,170 Average number of common shares outstanding used to calculate diluted earnings per common share 25,242,737 24,510,092 Earnings per common share: Basic $ 0.24 $ 0.16 Diluted $ 0.23 $ 0.16 Nine Months Ended September 30, 2018 2017 (In thousands, except share amounts) Net income applicable to common stock $ 18,829 $ 15,196 Average number of common shares outstanding 26,875,768 26,855,598 Less: Average unallocated ESOP shares (1,945,309 ) (2,021,219 ) Less: Average unvested restricted stock awards (710,404 ) (888,494 ) Average number of common shares outstanding used to calculate basic earnings per common share 24,220,055 23,945,885 Effect of dilutive stock options 534,257 178,712 Effect of dilutive unvested restricted stock awards 266,846 253,065 Average number of common shares outstanding used to calculate diluted earnings per common share 25,021,158 24,377,662 Earnings per common share: Basic $ 0.78 $ 0.63 Diluted $ 0.75 $ 0.62

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The Company made the following awards of options to purchase shares of common stock during the nine months ended September 30, 2018 : Options granted 214,500 Vesting period (years) 5 Term (years) 10 Fair value calculation assumptions: Expected volatility 25.40%-26.47% Expected life (years) 6.5 Expected dividend yield 3.21%-3.47% Risk free interest rate 2.39%-2.80% Weighted average grant date fair value $4.12-$4.13
Schedule of Share-based Compensation, Stock Options, Activity	A summary of the status of the Company's stock option grants for the nine months ended September 30, 2018 , is presented in the table below: Stock Option Awards Weighted Average Exercise Price Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at December 31, 2017 2,684,650 $ 14.70 Granted 214,500 21.04 Forfeited (79,120 ) 14.31 Exercised (60,500 ) 14.10 426,000 Outstanding at September 30, 2018 2,759,530 $ 15.21 7.42 $ 24,522,000 Exercisable at September 30, 2018 963,080 $ 14.42 7.14 $ 9,326,000 Unrecognized compensation cost inclusive of directors' options at September 30, 2018 $ 5,769,000 Weighted average remaining recognition period (years) 2.69
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	The following table presents the activity in non-vested stock awards under the Equity Plan for the nine months ended September 30, 2018 : Outstanding Restricted Stock Awards Weighted Average Grant Price Nonvested stock awards at December 31, 2017 730,420 $ 15.11 Granted 59,300 21.10 Vested (50,882 ) 17.09 Forfeited (24,890 ) 14.31 Nonvested stock awards at September 30, 2018 713,948 $ 15.50 Unrecognized compensation cost inclusive of directors' awards at September 30, 2018 $8,211,000 Weighted average remaining recognition period (years) 2.70

Basis of Presentation and Con_3

Basis of Presentation and Consolidation - Narrative (Details)	9 Months Ended
	Sep. 30, 2018	Sep. 20, 2018$ / shares	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Retained earnings
Subsidiary or Equity Method Investee [Line Items]
Cumulative effect on change in accounting principle				$ (27,000)
ASU 2018-02 | Retained earnings
Subsidiary or Equity Method Investee [Line Items]
Cumulative effect on change in accounting principle			$ 279,000
ASU 2016-01 | Retained earnings
Subsidiary or Equity Method Investee [Line Items]
Cumulative effect on change in accounting principle			$ 173,000
1-4 Family Residential
Subsidiary or Equity Method Investee [Line Items]
Origination covenants, maximum loan-to-value ratio (greater than) (percent)	80.00%
Rockland Trust
Subsidiary or Equity Method Investee [Line Items]
Share conversion ratio		0.2308
Cash received per share (in usd per share) | $ / shares		$ 5.25
Cash received per outstanding option (in usd per share) | $ / shares		$ 26.25

Accounting Standards Updates -

Accounting Standards Updates - Narrative (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future lease commitments	$ 19,900,000
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle ASU 2016-01 (Note 2)			$ (27,000)
Retained earnings | ASU 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle ASU 2016-01 (Note 2)		$ 279,000
Retained earnings | ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting principle ASU 2016-01 (Note 2)		$ 173,000

Securities - Available-for-sale

Securities - Available-for-sale Securities (Details) $ in Thousands	Dec. 31, 2017USD ($)
Marketable equity securities
Amortized Cost	$ 9,437
Gross Unrealized Gains	755
Gross Unrealized Losses	(472)
Fair Value	$ 9,720

Securities - Held-to-maturity S

Securities - Held-to-maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt securities:
Amortized Cost	$ 305,935	$ 303,716
Gross Unrealized Gains	38	58
Gross Unrealized Losses	(12,025)	(4,660)
Fair Value	293,948	299,114
Government-sponsored enterprises
Debt securities:
Amortized Cost	30,688	30,673
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,358)	(894)
Fair Value	29,330	29,779
Government-sponsored mortgage-backed and collateralized mortgage obligations
Debt securities:
Amortized Cost	246,624	244,668
Gross Unrealized Gains	6	30
Gross Unrealized Losses	(9,668)	(3,437)
Fair Value	236,962	241,261
SBA asset-backed securities
Debt securities:
Amortized Cost	28,623	28,375
Gross Unrealized Gains	32	28
Gross Unrealized Losses	(999)	(329)
Fair Value	$ 27,656	$ 28,074

Securities - Schedule of Contra

Securities - Schedule of Contractual Maturities of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Within 1 year, Held to Maturity, Amortized Cost	$ 1,098
After 1 year through 5 years, Held to Maturity, Amortized Cost	23,040
After 5 years through 10 years, Held to Maturity, Amortized Cost	6,550
Single Maturity Date, Held to Maturity, Amortized Cost	30,688
Mortgage- and asset-backed securities and collateralized mortgage obligations - Amortized Basis	275,247
Amortized Cost	305,935	$ 303,716
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value [Abstract]
Within 1 year, Held to Maturity, Fair Value	1,088
After 1 year through 5 years, Held to Maturity, Fair Value	22,124
After 5 years through 10 years, Held to Maturity, Fair Value	6,118
Single Maturity Date, Held to Maturity, Fair Value	29,330
Mortgage- and asset-backed securities and collateralized mortgage obligations - Fair Value	264,618
Held-to-maturity securities, total debt securities	$ 293,948	$ 299,114

Securities - Available-for-sa_2

Securities - Available-for-sale Securities Unrealized Loss (Details) $ in Thousands	Dec. 31, 2017USD ($)
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] (Deprecated 2018-01-31)
Gross Unrealized Losses - Less than twelve months	$ (449)
Gross Unrealized Losses - More than twelve months	(23)
Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract]
Fair Value - Less than twelve months	4,310
Fair Value - More than twelve months	$ 443

Securities - Held-to-maturity_2

Securities - Held-to-maturity Securities Unrealized Loss (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] (Deprecated 2018-01-31)
Gross Unrealized Losses - Less than twelve months	$ (1,867)	$ (1,706)
Gross Unrealized Losses - More than twelve months	(10,158)	(2,954)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	70,847	138,200
Fair Value - More than twelve months	219,579	144,393
Government-sponsored enterprises
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] (Deprecated 2018-01-31)
Gross Unrealized Losses - Less than twelve months	(65)	(109)
Gross Unrealized Losses - More than twelve months	(1,293)	(785)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	3,031	8,521
Fair Value - More than twelve months	26,299	21,258
Government-sponsored mortgage-backed and collateralized mortgage obligations
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] (Deprecated 2018-01-31)
Gross Unrealized Losses - Less than twelve months	(1,608)	(1,563)
Gross Unrealized Losses - More than twelve months	(8,060)	(1,874)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	61,656	119,782
Fair Value - More than twelve months	174,794	111,712
SBA asset-backed securities
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] (Deprecated 2018-01-31)
Gross Unrealized Losses - Less than twelve months	(194)	(34)
Gross Unrealized Losses - More than twelve months	(805)	(295)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	6,160	9,897
Fair Value - More than twelve months	$ 18,486	$ 11,423

Securities - Narrative (Details

Securities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Proceeds from sale of equity securities	$ 4,800	$ 4,772	$ 0
Mortgage and asset-backed securities and collateralized mortgage obligations, weighted average duration		4 years 1 day
Net unrealized gains on equity securities	$ 593
Proceeds from sale of available-for-sale securities		$ 0	213,084
Available-for-sale securities, gross realized gains			2,200
Available-for-sale securities, gross realized losses			$ (2,300)
Held-to-maturity securities, depreciation, percentage of amortized cost basis	4.00%	4.00%

Loans and The Allowance for L_3

Loans and The Allowance for Loan Losses - Summary of Loan Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 2,303,180		$ 2,203,810
Allowance for loan losses	(19,920)	$ (20,125)	(20,877)	$ (20,248)	$ (19,917)	$ (18,750)
Discount and fair value adjustments on purchased loans	(1,126)		(1,477)
Deferred loan costs and fees, net	4,662		4,691
Loans, net	2,286,796		2,186,147
Consumer and Commercial Portfolio Segment | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	75,390		91,050
Allowance for loan losses	(1,156)	(1,479)	(1,708)	(1,779)	(1,610)	(1,353)
Consumer, Excluding Consumer Other Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,003,091		1,928,603
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,003,731		922,627
Allowance for loan losses	(5,364)	(5,372)	(5,076)	(5,095)	(4,973)	(4,846)
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	70,071		80,662
Allowance for loan losses	(576)	(603)	(699)	(670)	(609)	(537)
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	853,899		834,264
Allowance for loan losses	(8,998)	(8,992)	(9,584)	(8,834)	(8,987)	(8,374)
Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	283,200		253,509
Allowance for loan losses	(3,567)	(3,389)	(3,473)	(3,511)	(3,352)	(3,206)
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	16,889		21,698
Allowance for loan losses	$ (259)	$ (290)	$ (337)	$ (359)	$ (386)	$ (434)

Loans and The Allowance for L_4

Loans and The Allowance for Loan Losses - Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	$ 20,125	$ 19,917	$ 20,877	$ 18,750
Provision (credit) for loan losses	(182)	242	(541)	1,417
Loans charged-off	(23)	(36)	(435)	(127)
Recoveries	0	125	19	208
Loans and Leases Receivable, Ending Allowance	19,920	20,248	19,920	20,248
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	5,372	4,973	5,076	4,846
Provision (credit) for loan losses	(8)	(3)	288	102
Loans charged-off	0	0	0	(52)
Recoveries	0	125	0	199
Loans and Leases Receivable, Ending Allowance	5,364	5,095	5,364	5,095
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	603	609	699	537
Provision (credit) for loan losses	(27)	61	(123)	133
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	576	670	576	670
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	8,992	8,987	9,584	8,374
Provision (credit) for loan losses	6	(153)	(392)	460
Loans charged-off	0	0	(194)	0
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	8,998	8,834	8,998	8,834
Consumer and Commercial Portfolio Segment | Construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	1,479	1,610	1,708	1,353
Provision (credit) for loan losses	(323)	169	(552)	426
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	1,156	1,779	1,156	1,779
Commercial business
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	3,389	3,352	3,473	3,206
Provision (credit) for loan losses	178	159	261	296
Loans charged-off	0	0	(178)	0
Recoveries	0	0	11	9
Loans and Leases Receivable, Ending Allowance	3,567	3,511	3,567	3,511
Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	290	386	337	434
Provision (credit) for loan losses	(8)	9	(23)	0
Loans charged-off	(23)	(36)	(63)	(75)
Recoveries	0	0	8	0
Loans and Leases Receivable, Ending Allowance	$ 259	$ 359	$ 259	$ 359

Loans and The Allowance for L_5

Loans and The Allowance for Loan Losses - Additional Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	$ 45		$ 81
Allowance related to non-impaired loans	19,875		20,796
Total allowance for loan losses	19,920	$ 20,125	20,877	$ 20,248	$ 19,917	$ 18,750
Impaired loans	12,263		12,282
Non-impaired loans	2,290,917		2,191,528
Total loans	2,303,180		2,203,810
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	45		80
Allowance related to non-impaired loans	5,319		4,996
Total allowance for loan losses	5,364	5,372	5,076	5,095	4,973	4,846
Impaired loans	6,801		5,949
Non-impaired loans	996,930		916,678
Total loans	1,003,731		922,627
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		0
Allowance related to non-impaired loans	576		699
Total allowance for loan losses	576	603	699	670	609	537
Impaired loans	1,814		1,387
Non-impaired loans	68,257		79,275
Total loans	70,071		80,662
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		0
Allowance related to non-impaired loans	8,998		9,584
Total allowance for loan losses	8,998	8,992	9,584	8,834	8,987	8,374
Impaired loans	3,386		4,744
Non-impaired loans	850,513		829,520
Total loans	853,899		834,264
Consumer and Commercial Portfolio Segment | Construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		0
Allowance related to non-impaired loans	1,156		1,708
Total allowance for loan losses	1,156	1,479	1,708	1,779	1,610	1,353
Impaired loans	0		0
Non-impaired loans	75,390		91,050
Total loans	75,390		91,050
Commercial business
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		0
Allowance related to non-impaired loans	3,567		3,473
Total allowance for loan losses	3,567	3,389	3,473	3,511	3,352	3,206
Impaired loans	163		0
Non-impaired loans	283,037		253,509
Total loans	283,200		253,509
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		1
Allowance related to non-impaired loans	259		336
Total allowance for loan losses	259	$ 290	337	$ 359	$ 386	$ 434
Impaired loans	99		202
Non-impaired loans	16,790		21,496
Total loans	$ 16,889		$ 21,698

Loans and The Allowance for L_6

Loans and The Allowance for Loan Losses - Summary of Past Due and Non-accrual loans, by class (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 4,970	$ 8,190
Loans on Non-accrual	11,784	11,523
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,548	997
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,356	368
Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,066	6,825
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,241	2,913
Loans on Non-accrual	6,339	5,190
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,609	1,178
Loans on Non-accrual	1,814	1,387
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	3,893
Loans on Non-accrual	3,386	4,744
Consumer, Excluding Consumer Other Portfolio Segment | 30-59 Days Past Due | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	970	381
Consumer, Excluding Consumer Other Portfolio Segment | 30-59 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	483	509
Consumer, Excluding Consumer Other Portfolio Segment | 30-59 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Consumer, Excluding Consumer Other Portfolio Segment | 60-89 Days Past Due | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	664	348
Consumer, Excluding Consumer Other Portfolio Segment | 60-89 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	692	13
Consumer, Excluding Consumer Other Portfolio Segment | 60-89 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Past Due 90 Days or More | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,607	2,184
Consumer, Excluding Consumer Other Portfolio Segment | Past Due 90 Days or More | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	434	656
Consumer, Excluding Consumer Other Portfolio Segment | Past Due 90 Days or More | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	3,893
Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Loans on Non-accrual	163
Commercial business | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Commercial business | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Commercial business | Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	120	206
Loans on Non-accrual	82	202
Consumer | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	95	107
Consumer | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	7
Consumer | Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 25	$ 92

Loans and The Allowance for L_7

Loans and The Allowance for Loan Losses - Summary of Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Recorded Investment
Recorded Investment, without valuation allowance	$ 10,909	$ 10,823
Recorded Investment, with a valuation allowance		1,459
Recorded Investment, total	12,263	12,282
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	11,758	11,880
Unpaid Principal Balance, with a valuation allowance		1,459
Unpaid Principal Balance, total	13,112	13,339
Related Allowance	45	81
1-4 Family Residential
Recorded Investment
Recorded Investment, with a valuation allowance	1,354	1,448
Unpaid Principal Balance
Unpaid Principal Balance, with a valuation allowance	1,354	1,448
Related Allowance	45	80
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Recorded Investment
Recorded Investment, without valuation allowance	5,447	4,501
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	5,844	4,897
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Recorded Investment
Recorded Investment, without valuation allowance	1,814	1,387
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	1,944	1,523
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Recorded Investment
Recorded Investment, without valuation allowance	3,386	4,744
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	3,543	5,206
Commercial business
Recorded Investment
Recorded Investment, without valuation allowance	163	0
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	314	11
Consumer
Recorded Investment
Recorded Investment, without valuation allowance	99	191
Recorded Investment, with a valuation allowance		11
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	$ 113	243
Unpaid Principal Balance, with a valuation allowance		11
Related Allowance		$ 1

Loans and The Allowance for L_8

Loans and The Allowance for Loan Losses - Summary of Average Recorded Investments and Interest Income of Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 11,468	$ 12,601	$ 11,341	$ 11,946
Interest Income Recognized	132	240	384	474
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	6,331	6,041	6,159	6,330
Interest Income Recognized	75	60	225	220
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	2,019	1,198	1,688	1,234
Interest Income Recognized	20	6	65	35
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	2,850	4,933	3,210	3,970
Interest Income Recognized	30	172	76	207
Consumer
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	97	340	122	251
Interest Income Recognized	1	2	4	7
Commercial business
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	171	89	162	161
Interest Income Recognized	$ 6	$ 0	$ 14	$ 5

Loans and The Allowance for L_9

Loans and The Allowance for Loan Losses - Summary of Troubled Debt Restructurings (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	5
Pre-Modification Outstanding Recorded Investment	$ 2,391
Post-Modification Outstanding Recorded Investment	$ 2,397
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1
Pre-Modification Outstanding Recorded Investment	$ 1,563
Post-Modification Outstanding Recorded Investment	$ 1,563
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	3
Pre-Modification Outstanding Recorded Investment	$ 469
Post-Modification Outstanding Recorded Investment	$ 475
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1
Pre-Modification Outstanding Recorded Investment	$ 359
Post-Modification Outstanding Recorded Investment	$ 359

Loans and The Allowance for _10

Loans and The Allowance for Loan Losses - Summary of Loan by Risk Rating (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 2,303,180	$ 2,203,810
Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,184,726	1,166,925
Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	26,479	9,896
Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	11,004	10,355
Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	242	250
Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,080,729	1,016,384
Consumer, Excluding Consumer Other Portfolio Segment
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,003,091	1,928,603
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,003,731	922,627
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	70,071	80,662
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	853,899	834,264
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	994	1,022
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	328	270
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	841,437	821,815
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,694	2,848
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,853	1,523
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,316	4,660
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,750	2,566
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,146	7,789
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 9 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	242	250
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 9 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 9 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 10 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 10 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 10 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer, Excluding Consumer Other Portfolio Segment | Loans not rated | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	996,051	915,941
Consumer, Excluding Consumer Other Portfolio Segment | Loans not rated | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	67,890	78,869
Consumer, Excluding Consumer Other Portfolio Segment | Loans not rated | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	75,390	91,050
Consumer and Commercial Portfolio Segment | Loans rated 1 - 6 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	75,390	91,050
Consumer and Commercial Portfolio Segment | Loans rated 7 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans rated 8 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans rated 9 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans rated 10 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer and Commercial Portfolio Segment | Loans not rated | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	283,200	253,509
Commercial business | Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	266,574	252,765
Commercial business | Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	15,534	744
Commercial business | Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,092	0
Commercial business | Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial business | Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial business | Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	16,889	21,698
Consumer | Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	3	3
Consumer | Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	82	121
Consumer | Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	16	0
Consumer | Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer | Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer | Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 16,788	$ 21,574

Other Real Estate Owned - Narra

Other Real Estate Owned - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)property	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)property	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Banking and Thrift [Abstract]
Other real estate owned properties | property	1		1
Other real estate owned	$ 3,649,000		$ 3,649,000		$ 0
Noninterest expenses applicable to foreclosed assets	$ 12,000	$ 2,000	$ 84,000	$ 11,000

Derivatives - Derivative Financ

Derivatives - Derivative Financial Instruments Not Designated as hedging Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative Gains, notional amount	$ 666,290	$ 610,077
Derivative Gains, fair value	18,493	8,766
Derivative Losses, notional amount	675,585	636,681
Derivative Losses, fair value	18,484	8,785
Commercial loan level interest rate swap agreements
Derivatives, Fair Value [Line Items]
Derivative Gains, notional amount	629,078	582,388
Derivative Gains, fair value	18,458	8,741
Derivative Losses, notional amount	629,078	582,388
Derivative Losses, fair value	18,458	8,741
Other contracts
Derivatives, Fair Value [Line Items]
Derivative Gains, notional amount	37,212	27,689
Derivative Gains, fair value	35	25
Derivative Losses, notional amount	46,507	54,293
Derivative Losses, fair value	$ 26	$ 44

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
TBA Securities
Derivative [Line Items]
Notional amount	$ 16,000,000
Closed hedge not settled	12,000,000
Not Designated as Hedging Instrument | Interest Rate Lock Commitments - Best Efforts
Derivative [Line Items]
Notional amount	11,600,000
Not Designated as Hedging Instrument | Interest Rate Lock Commitments - Loans Held-for-sale - Best Efforts
Derivative [Line Items]
Notional amount	900,000
Not Designated as Hedging Instrument | Interest Rate Lock Commitments - Borrowers - Best Efforts
Derivative [Line Items]
Notional amount	$ 10,600,000
Not Designated as Hedging Instrument | Interest Rate Lock Commitments - Mandatory Delivery
Derivative [Line Items]
Notional amount		$ 22,400,000
Not Designated as Hedging Instrument | Interest Rate Lock Commitments - Borrowers - Mandatory Delivery
Derivative [Line Items]
Notional amount		18,300,000
Not Designated as Hedging Instrument | Interest Rate Lock Commitments - Loans Held-for-sale - Mandatory Delivery
Derivative [Line Items]
Notional amount		4,100,000
Not Designated as Hedging Instrument | Mortgage loan commitments best efforts
Derivative [Line Items]
Notional amount		25,300,000
Not Designated as Hedging Instrument | Mortgage Loan Commitments - Borrowers - Best Efforts
Derivative [Line Items]
Notional amount		16,400,000
Not Designated as Hedging Instrument | Mortgage Loan Commitments - Loans Held-for-sale - Best Efforts
Derivative [Line Items]
Notional amount		8,900,000
Not Designated as Hedging Instrument | Mortgage loan commitments mandatory delivery
Derivative [Line Items]
Notional amount		$ 0
Minimum | TBA Securities
Derivative [Line Items]
Settlement term	30 days
Maximum | TBA Securities
Derivative [Line Items]
Settlement term	90 days

Derivatives - Summary of Fair V

Derivatives - Summary of Fair Value and Location for Rate-Lock and Forward Loan Sale Commitments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative assets:	$ 18,493	$ 8,766
Derivative liabilities:	18,484	8,785
Mortgage Banking Derivatives
Derivative [Line Items]
Derivative assets:		232
Derivative liabilities:		105
Other assets
Derivative [Line Items]
Derivative assets:	294
Other assets | Total mortgage derivative commitments
Derivative [Line Items]
Derivative assets:	233	210
Other assets | Mortgage loan commitments best efforts
Derivative [Line Items]
Derivative assets:	73	210
Other assets | Mortgage loan commitments mandatory delivery
Derivative [Line Items]
Derivative assets:	160
Other assets | Total forward loan sale commitments
Derivative [Line Items]
Derivative assets:	61	22
Other assets | Forward loan sale commitments best efforts
Derivative [Line Items]
Derivative assets:	8	22
Other assets | Forward loan sale commitments mandatory delivery
Derivative [Line Items]
Derivative assets:	53
Other liabilities
Derivative [Line Items]
Derivative liabilities:	29
Other liabilities | Total mortgage derivative commitments
Derivative [Line Items]
Derivative liabilities:	9	36
Other liabilities | Mortgage loan commitments best efforts
Derivative [Line Items]
Derivative liabilities:	6	36
Other liabilities | Mortgage loan commitments mandatory delivery
Derivative [Line Items]
Derivative liabilities:	3
Other liabilities | Total forward loan sale commitments
Derivative [Line Items]
Derivative liabilities:	20	69
Other liabilities | Forward loan sale commitments best efforts
Derivative [Line Items]
Derivative liabilities:	11	$ 69
Other liabilities | Forward loan sale commitments mandatory delivery
Derivative [Line Items]
Derivative liabilities:	$ 9

Deposits - Summary of Deposit B

Deposits - Summary of Deposit Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
NOW and demand	$ 415,993	$ 381,316
Regular savings	206,726	221,004
Money market	620,529	646,603
Brokered money market	80,143	92,798
Total non-certificate accounts	1,323,391	1,341,721
Term certificates of $250,000 or more	179,926	134,649
Term certificates less than $250,000	382,684	313,733
Brokered term certificates	280,006	249,766
Total term certificate accounts	842,616	698,148
Total deposits	$ 2,166,007	$ 2,039,869

Deposits - Schedule of Contract

Deposits - Schedule of Contractual Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Amount
Amount - Within 1 year	$ 515,442
Amount - 1-2 years	201,257
Amount - 2-3 years	92,326
Amount - 3-4 years	28,191
Amount - 4 years and beyond	5,400
Total term certificate accounts	$ 842,616	$ 698,148
Weighted Average Rate
Weighted Average Rate - Within 1 year	1.79%
Weighted Average Rate - 1-2 years	1.98%
Weighted Average Rate - 2-3 years	2.49%
Weighted Average Rate - 3-4 years	2.07%
Weighted Average Rate - 4 years and beyond	1.67%
Weighted Average Rate	1.92%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets
Equity securities at fair value	$ 5,270	$ 0
Marketable equity securities		9,720
Level 1
Assets
Equity securities at fair value	5,270
Level 2
Assets
Equity securities at fair value	0
Level 3
Assets
Equity securities at fair value	0
Recurring
Assets
Equity securities at fair value	5,270
Marketable equity securities		9,720
Total assets	24,057	18,718
Liabilities
Interest rate swap agreements	18,513	8,890
Recurring | Level 1
Assets
Equity securities at fair value	5,270
Marketable equity securities		9,720
Total assets	5,270	9,720
Liabilities
Interest rate swap agreements	0	0
Recurring | Level 2
Assets
Equity securities at fair value	0
Marketable equity securities		0
Total assets	18,493	8,766
Liabilities
Interest rate swap agreements	18,484	8,785
Recurring | Level 3
Assets
Equity securities at fair value	0
Marketable equity securities		0
Total assets	294	232
Liabilities
Interest rate swap agreements	29	105
Interest rate swap agreements | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Interest rate swap agreements | Level 2
Assets
Interest rate swap agreements	18,493	8,766
Liabilities
Interest rate swap agreements	18,484	8,785
Interest rate swap agreements | Level 3
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Interest rate swap agreements | Recurring
Assets
Interest rate swap agreements	18,493	8,766
Liabilities
Interest rate swap agreements	18,484	8,785
Interest rate swap agreements | Recurring | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Interest rate swap agreements | Recurring | Level 2
Assets
Interest rate swap agreements	18,493	8,766
Liabilities
Interest rate swap agreements	18,484	8,785
Interest rate swap agreements | Recurring | Level 3
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments - best efforts | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments - best efforts | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments - best efforts | Level 3
Assets
Interest rate swap agreements	8	22
Liabilities
Interest rate swap agreements	11	69
Forward loan sale commitments - best efforts | Recurring
Assets
Interest rate swap agreements	8	22
Liabilities
Interest rate swap agreements	11	69
Forward loan sale commitments - best efforts | Recurring | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments - best efforts | Recurring | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments - best efforts | Recurring | Level 3
Assets
Interest rate swap agreements	8	22
Liabilities
Interest rate swap agreements	11	69
Forward loan sale commitments mandatory delivery | Level 1
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Forward loan sale commitments mandatory delivery | Level 2
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Forward loan sale commitments mandatory delivery | Level 3
Assets
Interest rate swap agreements	53
Liabilities
Interest rate swap agreements	9
Forward loan sale commitments mandatory delivery | Recurring
Assets
Interest rate swap agreements	53
Liabilities
Interest rate swap agreements	9
Forward loan sale commitments mandatory delivery | Recurring | Level 1
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Forward loan sale commitments mandatory delivery | Recurring | Level 2
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Forward loan sale commitments mandatory delivery | Recurring | Level 3
Assets
Interest rate swap agreements	53
Liabilities
Interest rate swap agreements	9
Mortgage loan commitments best efforts | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments best efforts | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments best efforts | Level 3
Assets
Interest rate swap agreements	73	210
Liabilities
Interest rate swap agreements	6	36
Mortgage loan commitments best efforts | Recurring
Assets
Interest rate swap agreements	73	210
Liabilities
Interest rate swap agreements	6	36
Mortgage loan commitments best efforts | Recurring | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments best efforts | Recurring | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments best efforts | Recurring | Level 3
Assets
Interest rate swap agreements	73	210
Liabilities
Interest rate swap agreements	6	$ 36
Mortgage loan commitments mandatory delivery | Level 1
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Mortgage loan commitments mandatory delivery | Level 2
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Mortgage loan commitments mandatory delivery | Level 3
Assets
Interest rate swap agreements	160
Liabilities
Interest rate swap agreements	3
Mortgage loan commitments mandatory delivery | Recurring
Assets
Interest rate swap agreements	160
Liabilities
Interest rate swap agreements	3
Mortgage loan commitments mandatory delivery | Recurring | Level 1
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Mortgage loan commitments mandatory delivery | Recurring | Level 2
Assets
Interest rate swap agreements	0
Liabilities
Interest rate swap agreements	0
Mortgage loan commitments mandatory delivery | Recurring | Level 3
Assets
Interest rate swap agreements	160
Liabilities
Interest rate swap agreements	$ 3

Fair Value Measurements - Ass_2

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 4	$ 11	$ (346)	$ 2
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0		$ 0
Other real estate owned	0		0		0
Total assets	0		0		0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0		0
Other real estate owned	0		0		0
Total assets	0		0		0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	1,517		1,517		2,214
Other real estate owned	3,649		3,649		0
Total assets	$ 5,166		$ 5,166		$ 2,214

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value, Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financial assets:
Equity securities at fair value	$ 5,270	$ 0
Equity securities at fair value	0	9,720
Securities held to maturity	305,935	303,716
Estimate of Fair Value Measurement
Financial assets:
Cash and cash equivalents	47,749	46,167
Equity securities at fair value	5,270
Equity securities at fair value		9,720
Securities held to maturity	293,948	299,114
Federal Home Loan Bank stock	11,815	12,105
Loans and loans held for sale, net	2,267,797	2,174,871
Accrued interest receivable	7,143	6,438
Financial liabilities:
Deposits	2,160,039	2,036,150
Borrowings	176,902	203,913
Carrying Amount
Financial assets:
Cash and cash equivalents	47,749	46,167
Equity securities at fair value	5,270
Equity securities at fair value		9,720
Securities held to maturity	305,935	303,716
Federal Home Loan Bank stock	11,815	12,105
Loans and loans held for sale, net	2,291,831	2,195,139
Accrued interest receivable	7,143	6,438
Financial liabilities:
Deposits	2,166,007	2,039,869
Borrowings	178,000	205,000
Level 1
Financial assets:
Cash and cash equivalents	47,749	46,167
Equity securities at fair value	5,270
Equity securities at fair value		9,720
Securities held to maturity	0	0
Federal Home Loan Bank stock	0	0
Loans and loans held for sale, net	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	0	0
Borrowings	0	0
Level 2
Financial assets:
Cash and cash equivalents	0	0
Equity securities at fair value	0
Equity securities at fair value		0
Securities held to maturity	293,948	299,114
Federal Home Loan Bank stock	0	0
Loans and loans held for sale, net	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	0	0
Borrowings	176,902	203,913
Level 3
Financial assets:
Cash and cash equivalents	0	0
Equity securities at fair value	0
Equity securities at fair value		0
Securities held to maturity	0	0
Federal Home Loan Bank stock	11,815	12,105
Loans and loans held for sale, net	2,267,797	2,174,871
Accrued interest receivable	7,143	6,438
Financial liabilities:
Deposits	2,160,039	2,036,150
Borrowings	0	0
Interest rate swap agreements | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	18,493	8,766
Derivative liabilities:	18,484	8,785
Interest rate swap agreements | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	18,493	8,766
Derivative liabilities:	18,484	8,785
Interest rate swap agreements | Level 1
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Interest rate swap agreements | Level 2
On-balance sheet derivative financial instruments:
Derivative assets:	18,493	8,766
Derivative liabilities:	18,484	8,785
Interest rate swap agreements | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Mortgage loan commitments best efforts | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	73	210
Derivative liabilities:	6	36
Mortgage loan commitments best efforts | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	73	210
Derivative liabilities:	6	36
Mortgage loan commitments best efforts | Level 1
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Mortgage loan commitments best efforts | Level 2
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Mortgage loan commitments best efforts | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	73	210
Derivative liabilities:	6	36
Mortgage loan commitments mandatory delivery | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	160
Derivative liabilities:	3
Mortgage loan commitments mandatory delivery | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	160
Derivative liabilities:	3
Mortgage loan commitments mandatory delivery | Level 1
On-balance sheet derivative financial instruments:
Derivative assets:	0
Derivative liabilities:	0
Mortgage loan commitments mandatory delivery | Level 2
On-balance sheet derivative financial instruments:
Derivative assets:	0
Derivative liabilities:	0
Mortgage loan commitments mandatory delivery | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	160
Derivative liabilities:	3
Forward loan sale commitments best efforts | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	8	22
Derivative liabilities:	11	69
Forward loan sale commitments best efforts | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	8	22
Derivative liabilities:	11	69
Forward loan sale commitments best efforts | Level 1
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Forward loan sale commitments best efforts | Level 2
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Forward loan sale commitments best efforts | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	8	22
Derivative liabilities:	11	$ 69
Forward loan sale commitments mandatory delivery | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	53
Derivative liabilities:	9
Forward loan sale commitments mandatory delivery | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	53
Derivative liabilities:	9
Forward loan sale commitments mandatory delivery | Level 1
On-balance sheet derivative financial instruments:
Derivative assets:	0
Derivative liabilities:	0
Forward loan sale commitments mandatory delivery | Level 2
On-balance sheet derivative financial instruments:
Derivative assets:	0
Derivative liabilities:	0
Forward loan sale commitments mandatory delivery | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	53
Derivative liabilities:	$ 9

Comprehensive Income - Componen

Comprehensive Income - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ (1,809)	$ (1,453)
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized actuarial gain (loss)	(2,495)	(2,694)
Tax effect	514	914
Accumulated other comprehensive income	(1,981)	(1,780)
Securities Available for Sale | Accumulated Net Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized actuarial gain (loss)	0	283
Tax effect	0	(140)
Accumulated other comprehensive income	0	143
Securities Held to Maturity | Accumulated Net Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized actuarial gain (loss)	187	250
Tax effect	(15)	(66)
Accumulated other comprehensive income	$ 172	$ 184

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details)	Jan. 01, 2018	Dec. 31, 2017	Jan. 01, 2015
Equity [Abstract]
Tier one capital conservation buffer common equity capital to risk weighted assets (greater than)	1.875%	0.625%	2.50%

Stockholders' Equity - Minimum

Stockholders' Equity - Minimum Required Capital (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Total capital (to risk weighted assets)
Actual - Total Capital to Risk Weighted Assets	$ 415,901	$ 410,088
Actual - Total Capital to Risk Weighted Assets Ratio (percentage)	18.30%	19.70%
Minimum Capital Requirement - Total Capital	$ 182,234	$ 166,635
Minimum Capital Requirement - Total Capital to Risk Weighted Assets Ratio (percentage)	8.00%	8.00%
Minimum to Be Well Capitalized - Total Capital	$ 227,793	$ 208,294
Minimum to Be Well Capitalized - Total Capital to Risk Weighted Assets Ratio (percentage)	10.00%	10.00%
Tier 1 capital (to risk weighted assets)
Actual - Tier 1 Capital to Risk Weighted Assets	$ 395,981	$ 389,211
Actual - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	17.40%	18.70%
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets	$ 136,676	$ 124,977
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	6.00%	6.00%
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets	$ 182,234	$ 166,635
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	8.00%	8.00%
Common equity Tier 1 (to risk weighted assets)
Actual - Common Equity to Risk Weighted Assets	$ 395,981	$ 389,211
Actual - Common Equity to Risk Weighted Assets Ratio (percentage)	17.40%	18.70%
Minimum Capital Requirement - Common Equity to Risk Weighted Assets	$ 102,507	$ 93,732
Minimum Capital Requirement - Common Equity to Risk Weighted Assets Ratio (percentage)	4.50%	4.50%
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets	$ 148,065	$ 135,391
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets Ratio (percentage)	6.50%	6.50%
Tier 1 capital (to average assets)
Actual - Tier 1 Capital to Average Assets	$ 395,981	$ 389,211
Actual - Tier 1 Capital to Average Assets Ratio (percentage)	14.40%	14.90%
Minimum Capital Requirement - Tier 1 Capital to Average Assets	$ 109,770	$ 104,278
Minimum Capital Requirement - Tier 1 Capital to Average Assets Ratio (percentage)	4.00%	4.00%
Minimum to Be Well Capitalized - Tier 1 Capital to Average Assets	$ 137,212	$ 130,348
Minimum to Be Well Capitalized - Tier 1 Capital to Average Assets Ratio (percentage)	5.00%	5.00%
Blue Hills Bank
Total capital (to risk weighted assets)
Actual - Total Capital to Risk Weighted Assets	$ 365,926	$ 341,175
Actual - Total Capital to Risk Weighted Assets Ratio (percentage)	16.10%	16.40%
Minimum Capital Requirement - Total Capital	$ 182,059	$ 166,391
Minimum Capital Requirement - Total Capital to Risk Weighted Assets Ratio (percentage)	8.00%	8.00%
Minimum to Be Well Capitalized - Total Capital	$ 227,574	$ 207,988
Minimum to Be Well Capitalized - Total Capital to Risk Weighted Assets Ratio (percentage)	10.00%	10.00%
Tier 1 capital (to risk weighted assets)
Actual - Tier 1 Capital to Risk Weighted Assets	$ 346,006	$ 320,298
Actual - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	15.20%	15.40%
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets	$ 136,544	$ 124,793
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	6.00%	6.00%
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets	$ 182,059	$ 166,391
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	8.00%	8.00%
Common equity Tier 1 (to risk weighted assets)
Actual - Common Equity to Risk Weighted Assets	$ 346,006	$ 320,298
Actual - Common Equity to Risk Weighted Assets Ratio (percentage)	15.20%	15.40%
Minimum Capital Requirement - Common Equity to Risk Weighted Assets	$ 102,408	$ 93,595
Minimum Capital Requirement - Common Equity to Risk Weighted Assets Ratio (percentage)	4.50%	4.50%
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets	$ 147,923	$ 135,192
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets Ratio (percentage)	6.50%	6.50%
Tier 1 capital (to average assets)
Actual - Tier 1 Capital to Average Assets	$ 346,006	$ 320,298
Actual - Tier 1 Capital to Average Assets Ratio (percentage)	12.60%	12.30%
Minimum Capital Requirement - Tier 1 Capital to Average Assets	$ 109,664	$ 104,137
Minimum Capital Requirement - Tier 1 Capital to Average Assets Ratio (percentage)	4.00%	4.00%
Minimum to Be Well Capitalized - Tier 1 Capital to Average Assets	$ 137,080	$ 130,171
Minimum to Be Well Capitalized - Tier 1 Capital to Average Assets Ratio (percentage)	5.00%	5.00%

Employee Stock Ownership Plan -

Employee Stock Ownership Plan - Employee Stock Ownership Plan (Details) - shares	Sep. 30, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Allocated	291,617	219,860
Committed to be allocated	56,778	75,912
Unallocated	1,916,919	1,973,699
Total	2,265,314	2,269,471

Employee Stock Ownership Plan_2

Employee Stock Ownership Plan - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Retirement Benefits [Abstract]
ESOP, Number of shares committed to be released annually (shares)	75,912		75,912
Fair Value of unallocated shares	$ 46,200		$ 46,200		$ 39,700
ESOP expense	$ 434	$ 357	$ 1,209	$ 1,041

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income applicable to common stock	$ 5,789	$ 3,841	$ 18,829	$ 15,196
Average number of common shares outstanding	26,894,607	26,865,148	26,875,768	26,855,598
Less: Average unallocated ESOP shares	(711,219)	(2,002,397)	(710,404)	(2,021,219)
Less: Average unvested restricted stock awards	(1,926,486)	(889,635)	(1,945,309)	(888,494)
Average number of common shares outstanding used to calculate basic earnings per common share	24,256,902	23,973,116	24,220,055	23,945,885
Average number of common shares outstanding used to calculate diluted earnings per common share	25,242,737	24,510,092	25,021,158	24,377,662
Earnings per common share:
Basic (dollars per share)	$ 0.24	$ 0.16	$ 0.78	$ 0.63
Diluted (dollars per share)	$ 0.23	$ 0.16	$ 0.75	$ 0.62
Antidilutive securities excluded from computation of earnings per share (shares)	236,056	407,950	589,746	407,950
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effect of dilutive share-based compensation awards (in shares)	664,345	240,806	534,257	178,712
Unvested Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effect of dilutive share-based compensation awards (in shares)	321,490	296,170	266,846	253,065

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		45 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	2,846,681		2,846,681		2,846,681
Term (years)			10 years
Vesting period (years)			5 years
Share-based compensation expense	$ 589	$ 574	$ 1,700	$ 1,800
Tax benefit related to share-based compensation expense	$ 113	159	$ 332	475
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,138,673		1,138,673		1,138,673
Share-based compensation expense	$ 825	789	$ 2,400	2,400
Tax benefit related to share-based compensation expense	$ 232	$ 322	$ 674	$ 962
Granted (shares)			59,300
Vested (shares)			50,882
Nonvested (shares)	713,948		713,948		713,948	730,420
Forfeited (shares)			24,890
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)					40,000
Vested (shares)					12,000
Nonvested (shares)	24,000		24,000		24,000
Forfeited (shares)			2,000		4,000
Maximum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term (years)			10 years

Share-Based Compensation - Fair

Share-Based Compensation - Fair Value Assumptions (Details)	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (shares) | shares	214,500
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (shares) | shares	214,500
Vesting period (years)	5 years
Term (years)	10 years
Expected life (years)	6 years 6 months
Minimum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility (percent)	25.40%
Expected dividend yield (percent)	3.21%
Risk free interest rate (percent)	2.39%
Weighted average grant date fair value (dollars per share) | $ / shares	$ 4.12
Maximum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term (years)	10 years
Expected volatility (percent)	26.47%
Expected dividend yield (percent)	3.47%
Risk free interest rate (percent)	2.80%
Weighted average grant date fair value (dollars per share) | $ / shares	$ 4.13

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (shares)	2,684,650
Granted (shares)	214,500
Forfeited (shares)	(79,120)
Exercised (shares)	(60,500)
Ending balance (shares)	2,759,530
Exercisable at end of period (shares)	963,080
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance, weighted average exercise price (dollars per share) | $ / shares	$ 14.70
Granted, weighted average exercise price (dollars per share) | $ / shares	21.04
Forfeited, weighted average exercise price (dollars per share) | $ / shares	14.31
Exercised, weighted average exercise price (dollars per share) | $ / shares	14.10
Ending balance, weighted average exercise price (dollars per share) | $ / shares	15.21
Exercisable at end of period, weighted average exercise price (dollars per share) | $ / shares	$ 14.42
Outstanding, weighted average remaining contractual term (years)	7 years 5 months 1 day
Exercisable at period end, weighted average remaining contractual term (years)	7 years 1 month 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercised, aggregate intrinsic value | $	$ 426,000
Outstanding, aggregate intrinsic value | $	24,522,000
Exercisable, aggregate intrinsic value | $	$ 9,326,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted (shares)	214,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Unrecognized compensation cost | $	$ 5,769,000
Weighted average remaining recognition period (years)	2 years 8 months 9 days

Share-Based Compensation - Rest

Share-Based Compensation - Restricted Stock Activity (Details) - Restricted Stock - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (shares)	730,420
Granted (shares)	59,300
Vested (shares)	(50,882)
Forfeited (shares)	(24,890)
Ending balance (shares)	713,948
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance, weighted average exercise price (dollars per share)	$ 15.11
Granted, weighted average exercise price (dollars per share)	21.10
Vested, weighted average exercise price (dollars per share)	17.09
Forfeited, weighted average exercise price (dollars per share)	14.31
Ending balance, weighted average exercise price (dollars per share)	$ 15.50
Unrecognized compensation cost inclusive of directors' fees	$ 8,211
Weighted average remaining recognition period (years)	2 years 8 months 12 days