Blue Hills Bancorp (BHBK) 10-Q 4 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 01, 2017
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
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		26,864,088

Consolidated Balance Sheets (un

Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 17,292	$ 14,752
Short-term investments	33,819	15,744
Total cash and cash equivalents	51,111	30,496
Securities available-for-sale, at fair value	10,437	204,836
Securities held-to-maturity, at amortized cost	283,672	201,027
Federal Home Loan Bank stock, at cost	11,943	13,352
Loans held for sale	6,789	2,761
Loans, net of allowance for loan losses of $19,917 at June 30, 2017 and $18,750 at December 31, 2016	2,046,177	1,912,871
Premises and equipment, net	22,004	22,034
Accrued interest receivable	5,362	6,057
Goodwill	9,160	9,160
Core deposit intangible	931	1,400
Net deferred tax asset	8,184	10,146
Bank-owned life insurance	32,533	32,015
Other assets	25,606	23,537
Total assets	2,513,909	2,469,692
Deposits:
Non-interest bearing	203,912	184,982
Interest bearing	1,761,351	1,623,705
Total deposits	1,965,263	1,808,687
Short-term borrowings	0	146,000
Long-term debt	130,000	105,000
Accrued expenses and other liabilities	21,328	23,098
Total liabilities	2,116,591	2,082,785
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; 26,860,988 and 26,759,953 issued and outstanding at June 30, 2017 and December 31, 2016, respectively)	259	259
Additional paid-in capital	252,504	249,317
Unearned compensation-ESOP	(20,117)	(20,496)
Retained earnings	166,033	161,896
Accumulated other comprehensive loss	(1,361)	(4,069)
Total stockholders' equity	397,318	386,907
Total liabilities and stockholders' equity	$ 2,513,909	$ 2,469,692

Consolidated Balance Sheets (u3

Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Loans, net of allowance for loan losses of $19,917 at June 30, 2017 and $18,750 at December 31, 2016	$ 19,917	$ 18,750
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	26,860,988	26,759,953
Common stock, shares outstanding	26,860,988	26,759,953

Consolidated Statements of Net

Consolidated Statements of Net Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest and dividend income:
Interest and fees on loans	$ 18,715	$ 14,138	$ 36,097	$ 27,741
Interest on securities	1,572	2,037	3,782	4,332
Dividends	193	155	350	294
Other	94	26	126	52
Total interest and dividend income	20,574	16,356	40,355	32,419
Interest expense:
Interest on deposits	3,523	2,484	6,777	4,776
Interest on borrowings	643	556	1,289	1,126
Total interest expense	4,166	3,040	8,066	5,902
Net interest and dividend income	16,408	13,316	32,289	26,517
Provision for loan losses	1,118	1,113	1,175	1,086
Net interest and dividend income, after provision for loan losses	15,290	12,203	31,114	25,431
Non-interest income:
Deposit account fees	341	307	661	624
Interchange and ATM fees	388	393	736	740
Mortgage banking	1,219	531	1,959	775
Loan level derivative income	1,367	322	1,531	961
Gain (loss) on sales and calls of available-for-sale securities, net	928	664	(94)	420
Gain on exchange of investment in Northeast Retirement Services	0	0	5,947	0
Bank-owned life insurance income	261	257	518	514
Bank-owned life insurance death benefit gains	0	209	0	209
Miscellaneous	6	128	68	(55)
Total non-interest income	4,510	2,811	11,326	4,188
Non-interest expense:
Salaries and employee benefits	7,664	7,138	15,227	14,023
Occupancy and equipment	2,030	1,653	4,145	3,272
Data processing	1,022	803	2,066	1,564
Professional fees	526	678	1,395	1,159
Advertising	489	719	856	1,251
FDIC deposit insurance	223	352	435	698
Directors’ fees	428	399	802	737
Amortization of core deposit intangible	222	318	469	660
Other general and administrative	762	875	1,371	1,639
Total non-interest expense	13,366	12,935	26,766	25,003
Income before income taxes	6,434	2,079	15,674	4,616
Provision for income taxes	2,566	721	4,319	1,591
Net income	$ 3,868	$ 1,358	$ 11,355	$ 3,025
Earnings per common share:
Basic (dollars per share)	$ 0.16	$ 0.06	$ 0.47	$ 0.12
Diluted (dollars per share)	$ 0.16	$ 0.05	$ 0.47	$ 0.12
Weighted average shares outstanding:
Basic (shares)	23,952,443	24,575,211	23,932,044	24,817,260
Diluted (shares)	24,346,553	24,699,794	24,311,222	24,912,729

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income		$ 3,868	$ 1,358	$ 11,355	$ 3,025
Securities available-for-sale:
Change in unrealized holding gains		2,190	3,512	3,993	6,927
Reclassification adjustment for net losses realized in net income	[1]	(928)	(664)	94	(375)
Net change in unrealized gains		1,262	2,848	4,087	6,552
Tax effect		(523)	(994)	(1,427)	(2,288)
Net-of-tax amount		739	1,854	2,660	4,264
Securities held-to-maturity:
Reclassification adjustment for amortization of amounts previously recorded upon transfer from available-for-sale	[2]	(22)	(79)	(45)	(149)
Tax effect		9	28	5	53
Net-of-tax amount		(13)	(51)	(40)	(96)
Defined benefit pension plan:
Reclassification adjustment for net actuarial loss recognized in net periodic benefit cost	[3]	89	68	178	136
Tax effect		(31)	(24)	(90)	(48)
Net-of-tax amount		58	44	88	88
Other comprehensive income		784	1,847	2,708	4,256
Comprehensive income		$ 4,652	$ 3,205	$ 14,063	$ 7,281
[1]	Amounts are included in gain (loss) on sales and calls of available-for-sale securities, net, in the consolidated statements of net income. Income tax expense associated with the reclassification adjustments for the three months ended June 30, 2017 and 2016 was $324,000 and $231,000, respectively. Income tax (benefit) expense associated with the reclassification adjustments for the six months ended June 30, 2017 and 2016 was $(32,000) and $131,000, respectively.
[2]	Amounts are included in interest income on securities in the consolidated statements of net income.
[3]	Amounts are included in salaries and benefits expense in the consolidated statements of net income.

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Reclassification adjustment for net losses realized in net income, tax	$ 324	$ 231	$ (32)	$ 131

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Unearned compensation- ESOP	Retained earnings	Accumulated other comprehensive loss
Beginning balance at Dec. 31, 2015	$ 398,829	$ 276	$ 269,078	$ (21,255)	$ 155,918	$ (5,188)
Beginning balance (shares) at Dec. 31, 2015		28,492,732
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	7,281				3,025	4,256
ESOP shares committed to be released	541		162	379
Common stock dividends paid ($0.05 and $0.30 per common share for the six months ended June 30, 2016 and 2017, respectively)	(1,229)				(1,229)
Repurchase of common stock (shares)		(1,116,940)
Repurchase of common stock	(15,851)	$ (11)	(15,840)
Restricted stock awards granted (shares)		31,450
Restricted stock awards forfeited (shares)		(9,400)
Share-based compensation expense	2,381		2,381
Ending balance at Jun. 30, 2016	391,952	$ 265	255,781	(20,876)	157,714	(932)
Ending balance (shares) at Jun. 30, 2016		27,397,842
Beginning balance at Mar. 31, 2016						(2,779)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	3,205
Ending balance at Jun. 30, 2016	391,952	$ 265	255,781	(20,876)	157,714	(932)
Ending balance (shares) at Jun. 30, 2016		27,397,842
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle (Note 1)			27		(27)
Beginning balance at Dec. 31, 2016	386,907	$ 259	249,317	(20,496)	161,896	(4,069)
Beginning balance (shares) at Dec. 31, 2016		26,759,953
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	14,063				11,355	2,708
ESOP shares committed to be released	684		305	379
Common stock dividends paid ($0.05 and $0.30 per common share for the six months ended June 30, 2016 and 2017, respectively)	(7,191)				(7,191)
Restricted stock awards granted (shares)		175,695
Restricted stock awards forfeited (shares)		(84,417)
Share-based compensation expense	2,745		2,745
Share redemption for tax withholdings for restricted stock vesting (shares)		(5,903)
Share redemption for tax withholdings for restricted stock vesting	$ (107)		(107)
Proceeds from exercise of options (shares)	15,660	15,660
Proceeds from exercise of options	$ 217		217
Ending balance at Jun. 30, 2017	397,318	$ 259	252,504	(20,117)	166,033	(1,361)
Ending balance (shares) at Jun. 30, 2017		26,860,988
Beginning balance at Mar. 31, 2017						(2,145)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	4,652
Ending balance at Jun. 30, 2017	$ 397,318	$ 259	$ 252,504	$ (20,117)	$ 166,033	$ (1,361)
Ending balance (shares) at Jun. 30, 2017		26,860,988

Consolidated Statements of Cha8

Consolidated Statements of Changes in Stockholders' Equity (unaudited) (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Statement of Stockholders' Equity [Abstract]
Common stock paid (dollars per share)	$ 0.30	$ 0.05

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 11,355	$ 3,025
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	1,175	1,086
Net amortization of securities	1,007	1,836
Loss (gain) on sales and calls of available-for-sale securities, net	94	(420)
Net change in loans held for sale	(4,028)	(4,468)
Losses (gains) on sales of portfolio loans, net	74	(169)
Net amortization of net deferred loan origination costs and discounts	31	257
Depreciation and amortization of premises and equipment	1,062	951
Amortization of core deposit intangible	469	660
Bank-owned life insurance income, including death benefit gains	(518)	(723)
ESOP expense	684	541
Deferred income tax provision (benefit)	450	(576)
Share-based compensation expense	2,745	2,381
Gain on exchange of investment in Northeast Retirement Services	(5,947)	0
Net change in:
Accrued interest receivable	695	(296)
Other assets	(3,284)	(12,673)
Accrued expenses and other liabilities	(2,245)	11,374
Net cash provided by operating activities	3,819	2,786
Activity in securities available for sale:
Purchases	(13,951)	(30,305)
Sales	213,084	60,194
Maturities/calls	0	1,450
Principal paydowns	5,049	1,233
Activity in securities held to maturity:
Purchases	(97,591)	(23,366)
Maturities/calls	0	11,085
Principal paydowns	14,324	15,100
Loan originations and purchases, net of paydowns	(166,992)	(144,316)
Proceeds from residential portfolio loan sales	32,406	10,606
Net purchases of premises and equipment	(1,032)	(1,072)
Purchase of FHLBB stock	(4,309)	(2,855)
Redemption of FHLBB stock	5,718	3,589
Proceeds from exchange of investment in Northeast Retirement Services	1,595	0
Proceeds from bank-owned life insurance death benefit	0	791
Net cash used in investing activities	(11,699)	(97,866)
Cash flows from financing activities:
Net change in deposits, excluding brokered deposits	135,405	163,195
Net change in brokered deposits	21,171	3,862
Net change in short-term borrowings	(146,000)	(75,000)
Proceeds from long-term debt	25,000	30,000
Repurchase of common stock	0	(15,851)
Share redemption for tax withholdings for restricted stock vesting	(107)	0
Proceeds from exercise of stock options	217	0
Common stock dividends paid	(7,191)	(1,229)
Net cash provided by financing activities	28,495	104,977
Net change in cash and cash equivalents	20,615	9,897
Cash and cash equivalents at beginning of period	30,496	33,298
Cash and cash equivalents at end of period	51,111	43,195
Supplementary information:
Interest paid	7,978	5,822
Income taxes paid, net of refunds	4,240	2,517
Other real estate owned acquired in settlement of loans	$ 202	$ 0

Basis of Presentation and Conso

Basis of Presentation and Consolidation	6 Months Ended
	Jun. 30, 2017
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. 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, 2016, 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 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, or when in the judgment of management, the ultimate collectability of the principal or interest becomes doubtful, all interest previously accrued against interest income is reversed. 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. Prior to the second quarter of 2016, for portfolios for which the Company had insufficient loss experience, losses from a national peer group of depository institutions with assets between one and five billion dollars for relevant portfolios dating back to 2009 were used. Commencing in the second quarter of 2016, the Company began to phase in its own loss history by loan type based upon the age and loss experience of the loan portfolio. While this change impacted the loss factors used for our residential real estate, home equity, commercial real estate, commercial business and consumer loan portfolios, there was no material impact to the amount of the allowance for loan losses. Loss experience is updated at least quarterly with consideration given to unique 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, allocated and unallocated 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 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 2009, 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 has a loss sharing agreement. 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. Unallocated component The Company previously maintained an unallocated component to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance reflected the margin of imprecision inherent in the underlying assumptions used in the methodologies for estimating allocated and general reserves in the portfolio. As a large portion of the Company's loan portfolios is now seasoned, the unallocated component of the allowance for loan losses was eliminated during the fourth quarter of 2016. Change in accounting principle - Share-based compensation In March 2016, the Financial Accounting Standards Board ("FASB") issued an Accounting Standards Update ("ASU") 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. This Update amends its guidance on certain aspects of accounting for share-based payments to employees. The provisions of this Update became effective on January 1, 2017. The various changes applicable to adopting this Update include the following: Accounting for income taxes The Update states that entities will no longer record the excess tax benefits or deficiencies related to share-based compensation in additional paid in capital. Instead, they will record excess tax benefits or deficiencies in income tax expense or benefit in the income statement as part of the provision for income taxes on a prospective basis. For interim reporting purposes the excess tax benefits or deficiencies will be recorded as discrete items in the period in which they occur. The presentation of the excess tax benefits will be presented as an operating activity in the statement of cash flows. In addition, under the new guidance, when calculating incremental shares for earnings per share, entities exclude from assumed proceeds excess tax benefits that previously would have been recorded in additional paid in capital. The total income tax benefit recorded in the provision for income taxes relating to excess tax benefits on share-based compensation for the three and six months ended June 30, 2017 was $2,000 and $41,000 , respectively. One of the previous requirements for an award to qualify for equity classification was that an entity could not partially settle the award for cash in excess of the employer’s minimum statutory withholding requirements. The determination of an employee's minimum statutory withholding amount has been difficult for some entities. Under this Update, the threshold to qualify for equity classification would permit withholding up to the maximum individual statutory tax rate in the applicable jurisdictions. Also, the Update provides that cash paid by an employer when directly withholding shares for tax-withholding purposes would be classified as a financing activity in the statement of cash flows. Accounting for forfeitures Under this Update, the Company has elected to account for forfeitures of share-based payments by recognizing forfeitures of awards as they occur (e.g., when an award does not vest because the employee leaves the Company or does not meet specific performance measures). The transition to this methodology is applied on a modified retrospective basis, whereby the compensation cost will be calculated as if the entity did not historically record a forfeiture estimate for outstanding awards and instead accounted for forfeitures of outstanding awards as the forfeitures occurred, with a cumulative-effect adjustment to retained earnings. The cumulative effect of changing to this methodology resulted in a $27,000 adjustment to beginning retained earnings in the consolidated statement of changes in stockholders' equity for the six months ended June 30, 2017 .

Accounting Standards Updates

Accounting Standards Updates	6 Months Ended
	Jun. 30, 2017
Accounting Changes and Error Corrections [Abstract]
Accounting Standards Updates	DARDS UPDATES Recently Issued In May 2017, the FASB issued 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 is effective for public business entities for annual periods being after December 15, 2017, including interim periods within those annual periods. Early adoption is permitted including adopting in any interim period. The Update should be applied prospectively to awards modified on or after the effective date. The impact to the consolidated financial statements upon adopting this Update is not expected to be material. Future Application of Accounting Pronouncements Previously Issued In April 2017, the FASB issued ASU 2017-08 Receivables – Non-refundable Fees and Other Costs (Subtopic 310-20) , which shortens the period of amortization of the premium on certain callable debt securities to the earliest call date. Currently, generally accepted accounting principles (“GAAP”) excludes certain callable debt securities from consideration of early repayment of principal even if the holder is certain that the call will be exercised. As a result, upon the exercise of a call on a callable debt security held at a premium, the unamortized premium is recorded as a loss in earnings. This Update requires that premiums on certain callable debt securities be amortized to the shortest call date. Securities within the scope of this paragraph are those that have explicit, noncontingent call features that are callable at fixed prices and on preset dates. This Update is effective for public business entities for annual periods being after December 15, 2018, including interim periods within those annual periods. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity should apply the amendments from this Update on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The premium on all investments within the scope of this Update will need to be recalculated from date of purchase as if the premium was being amortized to the call date. The difference between this recalculated amount and the current remaining premium as of the beginning of the period of adoption is recorded as the cumulative effect decrease to retained earnings. The impact of adopting this update is not anticipated to be material to the financial statements, as of June 30, 2017 there were no premiums on callable debt securities that fall into this guidance. In January 2016, the FASB issued 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. For public business entities, the amendments in this Update are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. While the Company has performed a preliminary evaluation of the provisions of the Update, the effect of the adoption will depend on the Company’s portfolio at the time of transition. The Company does not anticipate that adoption of the Update will materially impact the Company's financial position. The Update also requires Companies to utilize an "exit price" fair value methodology when measuring the fair value of financial instruments. The impact of the change if applied to the equity investments for the six months ended June 30, 2017 would have resulted in a gain of $2,390,000 (pre tax) being recognized in net income, after reclassification for the realized loss on mutual funds, versus other comprehensive income. See the Consolidated Statement of Comprehensive Income. 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 31, 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 is currently evaluating the provisions of the Update to determine the potential impact the new standard will have on the Company's consolidated financial statements. 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 June 30, 2017 were $23.5 million . On June 16, 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. The Company is evaluating the provisions of the Update, and will closely monitor developments and additional guidance to determine the potential impact on the Company's consolidated financial statements. Management has established a steering committee which is in the process of identifying 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. In May 2014, the FASB issued ASU No. 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. This Update is effective for annual periods beginning after December 15, 2017, including interim periods within that reporting period with early adoption permitted. The timing of the Company’s revenue recognition is not expected to materially change. The Company's revenue relates principally to financial instruments, which are explicitly excluded from the scope of the new guidance. The Company will continue to evaluate any impact as additional guidance is issued and as our internal assessment progresses.

Securities

Securities	6 Months Ended
	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Securities	SECURITIES The amortized cost and estimated fair value of securities available-for-sale and held-to-maturity, with gross unrealized gains and losses, follows: June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available-for-Sale: Marketable equity securities $ 9,437 $ 1,247 $ (247 ) $ 10,437 Securities Held-to-Maturity: Debt securities: U.S. Treasury $ 24,990 $ 1 $ — $ 24,991 Government-sponsored enterprises 32,672 6 (678 ) 32,000 Government-sponsored mortgage-backed and collateralized mortgage obligations 202,877 65 (1,737 ) 201,205 SBA asset-backed securities 23,133 — (200 ) 22,933 Total securities held to maturity $ 283,672 $ 72 $ (2,615 ) $ 281,129 December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available-for-Sale: Debt securities: Mortgage- and other asset-backed securities: Privately issued commercial mortgage-backed securities $ 10,530 $ — $ (41 ) $ 10,489 Other asset-backed securities 9,174 6 (195 ) 8,985 Total mortgage- and other asset-backed securities 19,704 6 (236 ) 19,474 Municipal bonds 12,730 120 (157 ) 12,693 Financial services: Banks 20,263 57 (298 ) 20,022 Diversified financials 17,198 190 (198 ) 17,190 Insurance and REITs 18,304 150 (216 ) 18,238 Total financial services 55,765 397 (712 ) 55,450 Other corporate: Industrials 49,217 508 (761 ) 48,964 Utilities 24,895 292 (100 ) 25,087 Total other corporate 74,112 800 (861 ) 74,051 Total debt securities 162,311 1,323 (1,966 ) 161,668 Marketable equity securities: Mutual funds: Domestic community 3,216 25 (19 ) 3,222 Global asset allocation 42,396 48 (2,498 ) 39,946 Total marketable equity securities 45,612 73 (2,517 ) 43,168 Total securities available for sale $ 207,923 $ 1,396 $ (4,483 ) $ 204,836 Securities Held-to-Maturity: Debt securities: Government-sponsored enterprises $ 32,667 $ 4 $ (934 ) $ 31,737 Government-sponsored mortgage-backed and collateralized mortgage obligations 153,938 14 (1,806 ) 152,146 SBA asset-backed securities 14,422 — (212 ) 14,210 Total securities held to maturity $ 201,027 $ 18 $ (2,952 ) $ 198,093 The amortized cost and estimated fair value of debt securities by contractual maturity at June 30, 2017 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. Held to Maturity Amortized Cost Fair Value (In thousands) Within 1 year $ 29,993 $ 29,990 After 1 year through 5 years 9,689 9,534 After 5 years through 10 years 17,980 17,467 57,662 56,991 Mortgage- and asset-backed securities and collateralized mortgage obligations 226,010 224,138 $ 283,672 $ 281,129 For the three months ended June 30, 2017 and 2016 , proceeds from sales of securities available-for-sale amounted to $168.2 million and $44.7 million , respectively. Gross realized gains, for the same periods, amounted to $2.0 million and $1.2 million , respectively, and gross realized losses amounted to $1.0 million and $552,000 , respectively. For the six months ended June 30, 2017 and 2016 , proceeds from sales of securities available-for-sale amounted to $213.1 million and $60.2 million , respectively. Gross realized gains, for the same periods, amounted to $2.2 million and $1.4 million , respectively, and gross realized losses amounted to $2.3 million and $1.0 million , respectively. 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: June 30, 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 $ (226 ) $ 4,533 $ (21 ) $ 446 Securities Held-to-Maturity: Debt securities: Government-sponsored enterprises $ (678 ) $ 27,867 $ — $ — Government-sponsored mortgage-backed and collateralized mortgage obligations (1,701 ) 189,308 (36 ) 3,448 SBA asset-backed securities (89 ) 14,648 (111 ) 8,285 Total temporarily impaired held-to-maturity securities $ (2,468 ) $ 231,823 $ (147 ) $ 11,733 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 June 30, 2017 , multiple debt securities have unrealized losses with aggregate depreciation of approximately 1.0% 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 June 30, 2017 . Management has the ability and intent to hold the securities until maturity. At June 30, 2017 , the Company had two marketable equity securities with unrealized losses of $247,000 , or 4.7% depreciation from the Company’s cost basis. No issues have been identified that cause management to believe the declines in fair value are other than temporary and the Company has the ability and intent to hold these investments until a recovery of fair value. December 31, 2016 Less Than Twelve Months More Than Twelve Months Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (In thousands) Securities Available-for-Sale: Debt securities: Mortgage- and other asset-backed securities: Privately issued commercial mortgage-backed securities $ (11 ) $ 3,163 $ (30 ) $ 7,326 Other asset-backed securities (43 ) 3,924 (152 ) 3,732 Total mortgage- and other asset-backed securities (54 ) 7,087 (182 ) 11,058 Municipal bonds (157 ) 5,301 — — Financial services: Banks (298 ) 14,553 — — Diversified financials (198 ) 9,369 — — Insurance and REITs (216 ) 6,900 — — Total financial services (712 ) 30,822 — — Other corporate: Industrials (655 ) 24,630 (106 ) 2,284 Utilities (99 ) 11,200 (1 ) 794 Total other corporate (754 ) 35,830 (107 ) 3,078 Total debt securities (1,677 ) 79,040 (289 ) 14,136 Marketable equity securities: Mutual funds: Domestic community — — (19 ) 448 Global asset allocation (424 ) 15,153 (2,074 ) 22,442 Total marketable equity securities (424 ) 15,153 (2,093 ) 22,890 Total temporarily impaired available-for-sale securities $ (2,101 ) $ 94,193 $ (2,382 ) $ 37,026 Securities Held-to-Maturity: Debt securities: Government-sponsored enterprises $ (934 ) $ 28,533 $ — $ — Government-sponsored mortgage-backed and collateralized mortgage obligations (1,763 ) 146,098 (43 ) 3,827 SBA asset-backed securities (104 ) 9,157 (108 ) 5,053 Total temporarily impaired held-to-maturity securities $ (2,801 ) $ 183,788 $ (151 ) $ 8,880

Loans and The Allowance for Loa

Loans and The Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Loans and The Allowance for Loan Losses	LOANS AND THE ALLOWANCE FOR LOAN LOSSES A summary of the balances of loans follows: June 30, December 31, 2017 2016 (In thousands) Real estate: 1-4 family residential $ 891,608 $ 851,154 Home equity 84,104 78,719 Commercial real estate 756,474 687,289 Construction 78,320 76,351 1,810,506 1,693,513 Commercial business 227,812 206,234 Consumer 24,786 29,281 Total loans 2,063,104 1,929,028 Allowance for loan losses (19,917 ) (18,750 ) Discount and fair value adjustments on purchased loans (1,694 ) (1,846 ) Deferred loan costs and fees, net 4,684 4,439 Loans, net $ 2,046,177 $ 1,912,871 Activity in the allowance for loan losses for the three and six months ended June 30, 2017 and 2016 , by loan segment, follows: 1-4 Family Home Commercial Construction Commercial Consumer Unallocated Total (In thousands) Three Months Ended June 30, 2017 Allowance at March 31, 2017 $ 5,000 $ 558 $ 8,333 $ 1,457 $ 3,126 $ 401 $ — $ 18,875 Provision (credit) for loan losses 25 51 654 153 226 9 — 1,118 Loans charged-off (52 ) — — — — (24 ) — (76 ) Recoveries — — — — — — — — Allowance at June 30, 2017 $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ — $ 19,917 Three Months Ended June 30, 2016 Allowance at March 31, 2016 $ 3,665 $ 617 $ 7,338 $ 1,622 $ 2,619 $ 699 $ 425 $ 16,985 Provision (credit) for loan losses 275 (78 ) 284 125 671 (192 ) 28 1,113 Loans charged-off — — — — (8 ) (11 ) — (19 ) Recoveries — — — — — — — — Allowance at June 30, 2016 $ 3,940 $ 539 $ 7,622 $ 1,747 $ 3,282 $ 496 $ 453 $ 18,079 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Unallocated Total (In thousands) Six Months Ended June 30, 2017 Allowance at December 31, 2016 $ 4,846 $ 537 $ 8,374 $ 1,353 $ 3,206 $ 434 $ — $ 18,750 Provision (credit) for loan losses 105 72 613 257 137 (9 ) — 1,175 Loans charged-off (52 ) — — — — (39 ) — (91 ) Recoveries 74 — — — 9 — — 83 Allowance at June 30, 2017 $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ — $ 19,917 Six Months Ended June 30, 2016 Allowance at December 31, 2015 $ 3,916 $ 636 $ 7,147 $ 1,364 $ 2,839 $ 772 $ 428 $ 17,102 Provision (credit) for loan losses 24 (97 ) 475 383 523 (247 ) 25 1,086 Loans charged-off — — — — (113 ) (29 ) — (142 ) Recoveries — — — — 33 — — 33 Allowance at June 30, 2016 $ 3,940 $ 539 $ 7,622 $ 1,747 $ 3,282 $ 496 $ 453 $ 18,079 Additional information pertaining to the allowance for loan losses at June 30, 2017 and December 31, 2016 is as follows: 1-4 Family Home Commercial Construction Commercial Consumer Unallocated Total (In thousands) June 30, 2017 Allowance related to impaired loans $ 32 $ — $ — $ — $ — $ — $ — $ 32 Allowance related to non-impaired loans 4,941 609 8,987 1,610 3,352 386 — 19,885 Total allowance for loan losses $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ — $ 19,917 Impaired loans $ 6,277 $ 1,201 $ 5,024 $ — $ 177 $ 418 $ — $ 13,097 Non-impaired loans 885,331 82,903 751,450 78,320 227,635 24,368 — 2,050,007 Total loans $ 891,608 $ 84,104 $ 756,474 $ 78,320 $ 227,812 $ 24,786 $ — $ 2,063,104 December 31, 2016 Allowance related to impaired loans $ 17 $ — $ — $ — $ — $ — $ — $ 17 Allowance related to non-impaired loans 4,829 537 8,374 1,353 3,206 434 — 18,733 Total allowance for loan losses $ 4,846 $ 537 $ 8,374 $ 1,353 $ 3,206 $ 434 $ — $ 18,750 Impaired loans $ 6,726 $ 1,153 $ 941 $ — $ 241 $ 170 $ — $ 9,231 Non-impaired loans 844,428 77,566 686,348 76,351 205,993 29,111 — 1,919,797 Total loans $ 851,154 $ 78,719 $ 687,289 $ 76,351 $ 206,234 $ 29,281 $ — $ 1,929,028 The following is a summary of past due and non-accrual loans, by loan class, at June 30, 2017 and December 31, 2016 : 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) June 30, 2017 Real estate: 1-4 family residential $ 598 $ 653 $ 2,114 $ 3,365 $ 5,757 Home equity 674 14 572 1,260 1,201 Commercial real estate — — 4,126 4,126 5,024 Commercial business — — — — 177 Consumer 149 10 309 468 418 Total $ 1,421 $ 677 $ 7,121 $ 9,219 $ 12,577 December 31, 2016 Real estate: 1-4 family residential $ 584 $ 373 $ 2,322 $ 3,279 $ 6,478 Home equity 452 496 775 1,723 1,153 Commercial real estate 1,393 — — 1,393 941 Commercial business 4,996 13 — 5,009 241 Consumer 175 5 7 187 170 Total $ 7,600 $ 887 $ 3,104 $ 11,591 $ 8,983 There were no loans past due 90 days or more and still accruing interest at June 30, 2017 and December 31, 2016 . 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 June 30, 2017 (In thousands) Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 5,881 $ 6,085 $ — Home equity 1,201 1,305 — Commercial real estate 5,024 5,447 — Commercial business 177 287 — Consumer 418 425 — Total 12,701 13,549 — Impaired loans with a valuation allowance: 1-4 family residential 396 588 32 Total impaired loans $ 13,097 $ 14,137 $ 32 December 31, 2016 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 6,605 $ 7,023 $ — Home equity 1,153 1,225 — Commercial real estate 941 1,207 — Commercial business 241 3,279 — Consumer 170 183 — Total 9,110 12,917 — Impaired loans with a valuation allowance: 1-4 family residential 121 313 17 Total impaired loans $ 9,231 $ 13,230 $ 17 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 June 30, 2017 (In thousands) Real estate: 1-4 family residential $ 6,395 $ 82 Home equity 1,294 15 Commercial real estate 5,048 27 Commercial 200 2 Consumer 287 4 Total $ 13,224 $ 130 Three Months Ended June 30, 2016 Real estate: 1-4 family residential $ 6,508 $ 72 Home equity 381 4 Commercial real estate 4,819 38 Commercial 155 3 Consumer 1,519 — Total $ 13,382 $ 117 Six Months Ended June 30, 2017 Real estate: 1-4 family residential $ 6,505 $ 160 Home equity 1,247 29 Commercial real estate 3,679 35 Consumer 214 5 Commercial 249 5 Total $ 11,894 $ 234 Six Months Ended June 30, 2016 Real estate: 1-4 family residential $ 6,377 $ 145 Home equity 344 8 Commercial real estate 4,756 94 Consumer 151 5 Commercial 2,248 31 Total $ 13,876 $ 283 No additional funds are committed to be advanced in connection with impaired loans. There were no material troubled debt restructurings recorded during the three and six months ended June 30, 2017 or 2016 . 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 June 30, 2017 and December 31, 2016 : 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Total Loans (In thousands) June 30, 2017 Loans rated 1 - 6 $ 1,036 $ 283 $ 750,494 $ 78,320 $ 213,485 $ 4 $ 1,043,622 Loans rated 7 3,498 1,305 753 — 14,138 253 19,947 Loans rated 8 2,399 — 5,227 — 189 — 7,815 Loans rated 9 255 — — — — — 255 Loans rated 10 — — — — — — — Loans not rated 884,420 82,516 — — — 24,529 991,465 $ 891,608 $ 84,104 $ 756,474 $ 78,320 $ 227,812 $ 24,786 $ 2,063,104 December 31, 2016 Loans rated 1 - 6 $ 1,054 $ 293 $ 671,872 $ 76,351 $ 188,706 $ 4 $ 938,280 Loans rated 7 3,514 967 9,720 — 17,510 146 31,857 Loans rated 8 2,442 258 5,697 — 18 37 8,452 Loans rated 9 645 — — — — — 645 Loans rated 10 — — — — — — — Loans not rated 843,499 77,201 — — — 29,094 949,794 $ 851,154 $ 78,719 $ 687,289 $ 76,351 $ 206,234 $ 29,281 $ 1,929,028

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016 . Derivative Gains Derivative Losses Notional Amount Fair Value Notional Amount Fair Value (In thousands) June 30, 2017 Economic hedges: Commercial loan level interest rate swap agreements $ 495,404 $ 9,564 $ 495,404 $ 9,564 Other contracts 28,027 33 42,697 49 Total derivatives $ 523,431 $ 9,597 $ 538,101 $ 9,613 December 31, 2016 Economic hedges: Commercial loan level interest rate swap agreements $ 419,488 $ 9,016 $ 419,488 $ 8,932 Other contracts 15,685 8 33,045 56 Total derivatives $ 435,173 $ 9,024 $ 452,533 $ 8,988 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. The notional amounts of mortgage loan commitments as of June 30, 2017 and December 31, 2016 were $48.6 million and $6.8 million , respectively. The fair values of such commitments as of June 30, 2017 and December 31, 2016 included gains of $707,000 and $111,000 , respectively, recorded in other assets and losses of $24,000 and $3,000 , respectively, recorded in other liabilities on the consolidated balance sheets. To protect against the price risk inherent in derivative loan commitments, the Company utilizes “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. With a “best efforts” contract, 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, 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 forward sale commitments will experience changes in fair value opposite to the change in fair value of derivative loan commitments. The notional amounts of forward loan sale commitments at June 30, 2017 and December 31, 2016 were $55.3 million and $9.5 million , respectively. The fair values of such commitments as of June 30, 2017 and December 31, 2016 included gains of $27,000 and $15,000 , respectively, recorded in other assets and losses of $173,000 and $74,000 , respectively, recorded in other liabilities on the consolidated balance sheets.

Deposits

Deposits	6 Months Ended
	Jun. 30, 2017
Banking and Thrift [Abstract]
Deposits	DEPOSITS A summary of deposit balances, by type, is as follows: June 30, December 31, 2017 2016 (In thousands) NOW and demand $ 359,877 $ 331,508 Regular savings 246,484 262,984 Money market 674,593 573,204 Brokered money market 44,728 53,357 Total non-certificate accounts 1,325,682 1,221,053 Term certificates of $250,000 or more 90,988 77,550 Term certificates less than $250,000 271,273 262,564 Brokered term certificates 277,320 247,520 Total term certificate accounts 639,581 587,634 Total deposits $ 1,965,263 $ 1,808,687 At June 30, 2017 , the scheduled maturities of term certificate accounts, including brokered deposits, are as follows: Amount Weighted Average Rate (Dollars in thousands) Within 1 year $ 408,915 0.91 % 1-2 years 92,654 1.25 2-3 years 94,474 1.84 3-4 years 24,997 1.82 4 years and beyond 18,541 1.64 $ 639,581 1.15 %

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
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. The following methods and assumptions were used by the Company in estimating fair value disclosures for financial instruments: Cash and cash equivalents : The carrying amounts of cash and due from banks and short-term investments approximate 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. Federal Home Loan Bank stock : The carrying value of Federal Home Loan Bank stock approximates fair value based on the redemption provisions of the Federal Home Loan Bank. Loans : Fair values are estimated using discounted cash flow analyses, using market interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. Fair values for non-performing loans are estimated using discounted cash flow analyses or underlying collateral values, where applicable. Loans held for sale : Fair values are based on commitments in effect from investors or prevailing market prices. Accrued interest receivable : The carrying amount of accrued interest receivable approximates fair value. Deposits : The fair values for non-certificate accounts are, by definition, equal to the amount payable on demand at the reporting date (i.e., their carrying amounts). Fair values for certificate accounts are estimated using a discounted cash flow calculation that applies market interest rates currently being offered on certificates to a schedule of aggregated expected monthly maturities on time deposits. Borrowings : The fair value of borrowings are estimated using discounted cash flow analyses based on the current incremental borrowing rates in the market for similar types of borrowing arrangements. 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. Off-balance sheet instruments : Fair values for off-balance sheet lending commitments are based on fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the counterparties’ credit standing. The estimated fair value of off-balance sheet financial instruments at June 30, 2017 and December 31, 2016 , was immaterial since fees charged are not material. 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) June 30, 2017 Assets Securities available for sale: Marketable equity securities $ 10,437 $ — $ — $ 10,437 Derivative assets: Interest rate swap agreements — 9,597 — 9,597 Forward loan sale commitments — — 27 27 Mortgage loan commitments — — 707 707 Total assets $ 10,437 $ 9,597 $ 734 $ 20,768 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 9,604 $ — $ 9,604 Forward loan sale commitments — — 173 173 Mortgage loan commitments — — 24 24 Total liabilities $ — $ 9,604 $ 197 $ 9,801 December 31, 2016 Assets Securities available for sale: Debt securities $ — $ 161,668 $ — $ 161,668 Marketable equity securities 43,168 — — 43,168 Derivative assets: Interest rate swap agreements — 9,024 — 9,024 Forward loan sale commitments — — 15 15 Mortgage loan commitments — — 111 111 Total assets $ 43,168 $ 170,692 $ 126 $ 213,986 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 8,988 $ — $ 8,988 Forward loan sale commitments — — 74 74 Mortgage loan commitments — — 3 3 Total liabilities $ — $ 8,988 $ 77 $ 9,065 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: June 30, 2017 December 31, 2016 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 (In thousands) Impaired loans $ — $ — $ 573 $ — $ — $ 136 The following table summarizes the total losses on assets measured at fair value on a non-recurring basis for the three and six months ended June 30, 2017 and 2016 . Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (In thousands) Impaired loans $ (86 ) $ (528 ) $ (9 ) $ (307 ) 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) June 30, 2017 Financial assets: Cash and cash equivalents $ 51,111 $ 51,111 $ — $ — $ 51,111 Securities available for sale 10,437 10,437 — — 10,437 Securities held to maturity 283,672 24,991 256,138 — 281,129 Federal Home Loan Bank stock 11,943 — — 11,943 11,943 Loans and loans held for sale 2,052,966 — — 2,044,096 2,044,096 Accrued interest receivable 5,362 — — 5,362 5,362 Financial liabilities: Deposits 1,965,263 — — 1,964,672 1,964,672 Borrowings 130,000 — 129,525 — 129,525 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 9,597 — 9,597 — 9,597 Forward loan sale commitments 27 — — 27 27 Mortgage loan commitments 707 — — 707 707 Derivative liabilities: Interest rate swap agreements 9,604 — 9,604 — 9,604 Forward loan sale commitments 173 — — 173 173 Mortgage loan commitments 24 — — 24 24 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) December 31, 2016 Financial assets: Cash and cash equivalents $ 30,496 $ 30,496 $ — $ — $ 30,496 Securities available for sale 204,836 43,168 161,668 — 204,836 Securities held to maturity 201,027 — 198,093 — 198,093 Federal Home Loan Bank stock 13,352 — — 13,352 13,352 Loans and loans held for sale 1,915,632 — — 1,903,978 1,903,978 Accrued interest receivable 6,057 — — 6,057 6,057 Financial liabilities: Deposits 1,808,687 — — 1,808,629 1,808,629 Borrowings 251,000 — 250,648 — 250,648 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 9,024 — 9,024 — 9,024 Forward loan sale commitments 15 — — 15 15 Mortgage loan commitments 111 — — 111 111 Derivative liabilities: Interest rate swap agreements 8,988 — 8,988 — 8,988 Forward loan sale commitments 74 — — 74 74 Mortgage loan commitments 3 — — 3 3

Comprehensive Income

Comprehensive Income	6 Months Ended
	Jun. 30, 2017
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: June 30, December 31, 2017 2016 (In thousands) Securities available for sale: Net unrealized gain (loss) $ 1,000 $ (3,087 ) Tax effect (420 ) 1,007 Net-of-tax amount 580 (2,080 ) Securities held to maturity: Net unrealized gain on transferred securities 292 337 Tax effect (109 ) (114 ) Net-of-tax amount 183 223 Defined benefit pension plan: Unrecognized net actuarial loss (3,304 ) (3,482 ) Tax effect 1,180 1,270 Net-of-tax amount (2,124 ) (2,212 ) $ (1,361 ) $ (4,069 ) Changes in accumulated other comprehensive income (loss), by component, follow: Three Months Ended June 30, 2017 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at March 31, 2017 $ (159 ) $ 196 $ (2,182 ) $ (2,145 ) Other comprehensive income before reclassification adjustments 2,190 — — 2,190 Reclassification adjustments: Net realized gains (928 ) — — (928 ) Amortization of actuarial losses — — 89 89 Amortization of amounts previously recorded upon transfer from available-for-sale — (22 ) — (22 ) Tax effects (523 ) 9 (31 ) (545 ) Net current-period other comprehensive income (loss) 739 (13 ) 58 784 Balance at June 30, 2017 $ 580 $ 183 $ (2,124 ) $ (1,361 ) Three Months Ended June 30, 2016 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at March 31, 2016 $ (1,346 ) $ 329 $ (1,762 ) $ (2,779 ) Other comprehensive income before reclassification adjustments 3,512 — — 3,512 Reclassification adjustments: Net realized gains (664 ) — — (664 ) Amortization of actuarial losses — — 68 68 Amortization of amounts previously recorded upon transfer from available-for-sale — (79 ) — (79 ) Tax effects (994 ) 28 (24 ) (990 ) Net current-period other comprehensive income (loss) 1,854 (51 ) 44 1,847 Balance at June 30, 2016 $ 508 $ 278 $ (1,718 ) $ (932 ) Six Months Ended June 30, 2017 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at December 31, 2016 $ (2,080 ) $ 223 $ (2,212 ) $ (4,069 ) Other comprehensive income before reclassification adjustments 3,993 — — 3,993 Reclassification adjustments: Net realized losses 94 — — 94 Amortization of actuarial losses — — 178 178 Amortization of amounts previously recorded upon transfer from available-for-sale — (45 ) — (45 ) Tax effects (1,427 ) 5 (90 ) (1,512 ) Net current-period other comprehensive income (loss) 2,660 (40 ) 88 2,708 Balance at June 30, 2017 $ 580 $ 183 $ (2,124 ) $ (1,361 ) Six Months Ended June 30, 2016 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at December 31, 2015 $ (3,756 ) $ 374 $ (1,806 ) $ (5,188 ) Other comprehensive income before reclassification adjustments 6,927 — — 6,927 Reclassification adjustments: Net realized gains (375 ) — — (375 ) Amortization of actuarial losses — — 136 136 Amortization of amounts previously recorded upon transfer from available-for-sale — (149 ) — (149 ) Tax effects (2,288 ) 53 (48 ) (2,283 ) Net current-period other comprehensive income (loss) 4,264 (96 ) 88 4,256 Balance at June 30, 2016 $ 508 $ 278 $ (1,718 ) $ (932 )

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2017
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, 2017, the capital conservation buffer is 1.250% . 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 June 30, 2017. As of June 30, 2017 , 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 June 30, 2017 and December 31, 2016 , 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 June 30, 2017 and December 31, 2016 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.: June 30, 2017 Total capital (to risk weighted assets) $ 408,048 21.2 % $ 154,065 8.0 % 192,581 10.0 % Tier 1 capital (to risk weighted assets) 388,131 20.2 115,548 6.0 154,065 8.0 Common equity Tier 1 (to risk weighted assets) 388,131 20.2 86,661 4.5 125,177 6.5 Tier 1 capital (to average assets) 388,131 15.6 99,437 4.0 124,297 5.0 December 31, 2016 Total capital (to risk weighted assets) $ 395,325 20.5 % $ 154,471 8.0 % 193,089 10.0 % Tier 1 capital (to risk weighted assets) 376,575 19.5 115,854 6.0 154,471 8.0 Common equity Tier 1 (to risk weighted assets) 376,575 19.5 86,890 4.5 125,508 6.5 Tier 1 capital (to average assets) 376,575 16.0 94,166 4.0 117,708 5.0 Blue Hills Bank: June 30, 2017 Total capital (to risk weighted assets) $ 332,170 17.3 % $ 153,789 8.0 % $ 192,237 10.0 % Tier 1 capital (to risk weighted assets) 312,253 16.2 115,342 6.0 153,789 8.0 Common equity Tier 1 (to risk weighted assets) 312,253 16.2 86,507 4.5 124,954 6.5 Tier 1 capital (to average assets) 312,253 12.4 100,714 4.0 125,893 5.0 December 31, 2016 Total capital (to risk weighted assets) $ 313,457 16.3 % $ 154,196 8.0 % $ 192,745 10.0 % Tier 1 capital (to risk weighted assets) 294,707 15.3 115,647 6.0 154,196 8.0 Common equity Tier 1 (to risk weighted assets) 294,707 15.3 86,735 4.5 125,284 6.5 Tier 1 capital (to average assets) 294,707 12.5 94,099 4.0 117,623 5.0

Employee Stock Ownership Plan

Employee Stock Ownership Plan	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 December 31, 2016 Allocated 223,469 149,613 Committed to be allocated 37,644 75,912 Unallocated 2,011,964 2,049,608 2,273,077 2,275,133 The fair value of unallocated shares was $36.0 million and $38.4 million at June 30, 2017 and December 31, 2016 , respectively. Total compensation expense recognized in connection with the ESOP for the three months ended June 30, 2017 and 2016 was $343,000 and $276,000 , respectively. Total compensation expense recognized in connection with the ESOP for the six months ended June 30, 2017 and 2016 was $684,000 and 541,000 , respectively.

Earnings Per Common Share

Earnings Per Common Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Common Share	EARNINGS PER COMMON SHARE Basic earnings per 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 June 30, 2017 2016 (In thousands, except share amounts) Net income applicable to common stock $ 3,868 $ 1,358 Average number of common shares outstanding 26,859,345 27,678,337 Less: Average unallocated ESOP shares (2,021,427 ) (2,096,794 ) Less: Average unvested restricted stock awards (885,475 ) (1,006,332 ) Average number of common shares outstanding used to calculate basic earnings per common share 23,952,443 24,575,211 Effect of dilutive stock options 155,938 — Effect of dilutive unvested restricted stock awards 238,172 124,583 Average number of common shares outstanding used to calculate diluted earnings per common share 24,346,553 24,699,794 Earnings per common share: Basic $ 0.16 $ 0.06 Diluted $ 0.16 $ 0.05 Six Months Ended June 30, 2017 2016 (In thousands, except share amounts) Net income applicable to common stock $ 11,355 $ 3,025 Average number of common shares outstanding 26,851,143 27,914,044 Less: Average unallocated ESOP shares (2,030,786 ) (2,106,257 ) Less: Average unvested restricted stock awards (888,313 ) (990,527 ) Average number of common shares outstanding used to calculate basic earnings per common share 23,932,044 24,817,260 Effect of dilutive stock options 147,665 — Effect of dilutive unvested restricted stock awards 231,513 95,469 Average number of common shares outstanding used to calculate diluted earnings per common share 24,311,222 24,912,729 Earnings per common share: Basic $ 0.47 $ 0.12 Diluted $ 0.47 $ 0.12 Options for 372,100 and 2,462,350 shares were not included in the computation of diluted earnings per common share for the three months ended June 30, 2017 and 2016 , respectively, because to do so would have been anti-dilutive.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2017
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. The total number of shares reserved for restricted stock or restricted units is 1,138,673 . 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 six months ended June 30, 2017 . Options granted 372,100 Vesting period (years) 5 Term (years) 10 Expected volatility 27.20%-27.43% Expected life (years) 6.5 Expected dividend yield 0.71%-1.11% Risk free interest rate 2.02%-2.16% Fair value per option $4.88-$5.31 A summary of the status of the Company's stock option grants for the six months ended June 30, 2017 , 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, 2016 2,449,670 $ 14.06 — $ — Granted 372,100 18.23 — — Forfeited (150,500 ) 14.07 — — Exercised (15,660 ) 13.88 — 65,000 Outstanding at June 30, 2017 2,655,610 $ 14.65 8.47 $ 8,758,000 Exercisable at June 30, 2017 491,230 $ 14.07 8.28 $ 1,881,000 Unrecognized compensation cost inclusive of directors' options at June 30, 2017 $ 7,983,000 Weighted average remaining recognition period (years) 3.58 For the three months ended June 30, 2017 and 2016, share-based compensation expense applicable to the stock options was $568,000 and $ 485,000 , respectively, and the recognized tax benefit related to this expense was $135,000 and $125,000 . For the six months ended June 30, 2017 and 2016, share-based compensation expense applicable to the stock options was $1,178,000 and $996,000 , respectively, and the recognized tax benefit related to this expense was $290,000 and $250,000 . 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, 40,000 are performance based, of which 6,000 have vested, and 32,000 remain unvested. There were 2,000 performance shares forfeited during the six months ended June 30, 2017 . The following table presents the activity in non-vested stock awards under the Equity Plan for the six months ended June 30, 2017 : Outstanding Restricted Stock Awards Weighted Average Grant Price Nonvested stock awards at December 31, 2016 816,070 $ 14.06 Granted 175,695 18.25 Vested (21,873 ) 14.01 Forfeited (84,417 ) 14.07 Nonvested stock awards at June 30, 2017 885,475 $ 14.89 Unrecognized compensation cost inclusive of directors' awards at June 30, 2017 $11,137,000 Weighted average remaining recognition period (years) 3.65 For the three months ended June 30, 2017 and 2016, share-based compensation expense applicable to restricted stock awards was $ 770,000 and $701,000 , respectively, and the recognized tax benefit related to this expense was $269,000 and $247,000 respectively. For the six months ended June 30, 2017 and 2016, share-based compensation expense applicable to restricted stock awards was $1,567,000 and $1,385,000 , respectively, and the recognized tax benefit related to this expense was $574,000 and $489,000 respectively.

Basis of Presentation and Con22

Basis of Presentation and Consolidation (Policies)	6 Months Ended
	Jun. 30, 2017
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. 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, 2016, 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, or when in the judgment of management, the ultimate collectability of the principal or interest becomes doubtful, all interest previously accrued against interest income is reversed. 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. Prior to the second quarter of 2016, for portfolios for which the Company had insufficient loss experience, losses from a national peer group of depository institutions with assets between one and five billion dollars for relevant portfolios dating back to 2009 were used. Commencing in the second quarter of 2016, the Company began to phase in its own loss history by loan type based upon the age and loss experience of the loan portfolio. While this change impacted the loss factors used for our residential real estate, home equity, commercial real estate, commercial business and consumer loan portfolios, there was no material impact to the amount of the allowance for loan losses. Loss experience is updated at least quarterly with consideration given to unique 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, allocated and unallocated 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 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 2009, 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 has a loss sharing agreement. 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. Unallocated component The Company previously maintained an unallocated component to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance reflected the margin of imprecision inherent in the underlying assumptions used in the methodologies for estimating allocated and general reserves in the portfolio. As a large portion of the Company's loan portfolios is now seasoned, the unallocated component of the allowance for loan losses was eliminated during the fourth quarter of 2016.
Recent Accounting Standards Updates	Change in accounting principle - Share-based compensation In March 2016, the Financial Accounting Standards Board ("FASB") issued an Accounting Standards Update ("ASU") 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. This Update amends its guidance on certain aspects of accounting for share-based payments to employees. The provisions of this Update became effective on January 1, 2017. The various changes applicable to adopting this Update include the following: Accounting for income taxes The Update states that entities will no longer record the excess tax benefits or deficiencies related to share-based compensation in additional paid in capital. Instead, they will record excess tax benefits or deficiencies in income tax expense or benefit in the income statement as part of the provision for income taxes on a prospective basis. For interim reporting purposes the excess tax benefits or deficiencies will be recorded as discrete items in the period in which they occur. The presentation of the excess tax benefits will be presented as an operating activity in the statement of cash flows. In addition, under the new guidance, when calculating incremental shares for earnings per share, entities exclude from assumed proceeds excess tax benefits that previously would have been recorded in additional paid in capital. The total income tax benefit recorded in the provision for income taxes relating to excess tax benefits on share-based compensation for the three and six months ended June 30, 2017 was $2,000 and $41,000 , respectively. One of the previous requirements for an award to qualify for equity classification was that an entity could not partially settle the award for cash in excess of the employer’s minimum statutory withholding requirements. The determination of an employee's minimum statutory withholding amount has been difficult for some entities. Under this Update, the threshold to qualify for equity classification would permit withholding up to the maximum individual statutory tax rate in the applicable jurisdictions. Also, the Update provides that cash paid by an employer when directly withholding shares for tax-withholding purposes would be classified as a financing activity in the statement of cash flows. Accounting for forfeitures Under this Update, the Company has elected to account for forfeitures of share-based payments by recognizing forfeitures of awards as they occur (e.g., when an award does not vest because the employee leaves the Company or does not meet specific performance measures). The transition to this methodology is applied on a modified retrospective basis, whereby the compensation cost will be calculated as if the entity did not historically record a forfeiture estimate for outstanding awards and instead accounted for forfeitures of outstanding awards as the forfeitures occurred, with a cumulative-effect adjustment to retained earnings. The cumulative effect of changing to this methodology resulted in a $27,000 adjustment to beginning retained earnings in the consolidated statement of changes in stockholders' equity for the six months ended June 30, 2017 . DARDS UPDATES Recently Issued In May 2017, the FASB issued 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 is effective for public business entities for annual periods being after December 15, 2017, including interim periods within those annual periods. Early adoption is permitted including adopting in any interim period. The Update should be applied prospectively to awards modified on or after the effective date. The impact to the consolidated financial statements upon adopting this Update is not expected to be material. Future Application of Accounting Pronouncements Previously Issued In April 2017, the FASB issued ASU 2017-08 Receivables – Non-refundable Fees and Other Costs (Subtopic 310-20) , which shortens the period of amortization of the premium on certain callable debt securities to the earliest call date. Currently, generally accepted accounting principles (“GAAP”) excludes certain callable debt securities from consideration of early repayment of principal even if the holder is certain that the call will be exercised. As a result, upon the exercise of a call on a callable debt security held at a premium, the unamortized premium is recorded as a loss in earnings. This Update requires that premiums on certain callable debt securities be amortized to the shortest call date. Securities within the scope of this paragraph are those that have explicit, noncontingent call features that are callable at fixed prices and on preset dates. This Update is effective for public business entities for annual periods being after December 15, 2018, including interim periods within those annual periods. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity should apply the amendments from this Update on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The premium on all investments within the scope of this Update will need to be recalculated from date of purchase as if the premium was being amortized to the call date. The difference between this recalculated amount and the current remaining premium as of the beginning of the period of adoption is recorded as the cumulative effect decrease to retained earnings. The impact of adopting this update is not anticipated to be material to the financial statements, as of June 30, 2017 there were no premiums on callable debt securities that fall into this guidance. In January 2016, the FASB issued 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. For public business entities, the amendments in this Update are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. While the Company has performed a preliminary evaluation of the provisions of the Update, the effect of the adoption will depend on the Company’s portfolio at the time of transition. The Company does not anticipate that adoption of the Update will materially impact the Company's financial position. The Update also requires Companies to utilize an "exit price" fair value methodology when measuring the fair value of financial instruments. The impact of the change if applied to the equity investments for the six months ended June 30, 2017 would have resulted in a gain of $2,390,000 (pre tax) being recognized in net income, after reclassification for the realized loss on mutual funds, versus other comprehensive income. See the Consolidated Statement of Comprehensive Income. 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 31, 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 is currently evaluating the provisions of the Update to determine the potential impact the new standard will have on the Company's consolidated financial statements. 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 June 30, 2017 were $23.5 million . On June 16, 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. The Company is evaluating the provisions of the Update, and will closely monitor developments and additional guidance to determine the potential impact on the Company's consolidated financial statements. Management has established a steering committee which is in the process of identifying 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. In May 2014, the FASB issued ASU No. 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. This Update is effective for annual periods beginning after December 15, 2017, including interim periods within that reporting period with early adoption permitted. The timing of the Company’s revenue recognition is not expected to materially change. The Company's revenue relates principally to financial instruments, which are explicitly excluded from the scope of the new guidance. The Company will continue to evaluate any impact as additional guidance is issued and as our internal assessment progresses.

Securities (Tables)

Securities (Tables)	6 Months Ended
	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities	December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available-for-Sale: Debt securities: Mortgage- and other asset-backed securities: Privately issued commercial mortgage-backed securities $ 10,530 $ — $ (41 ) $ 10,489 Other asset-backed securities 9,174 6 (195 ) 8,985 Total mortgage- and other asset-backed securities 19,704 6 (236 ) 19,474 Municipal bonds 12,730 120 (157 ) 12,693 Financial services: Banks 20,263 57 (298 ) 20,022 Diversified financials 17,198 190 (198 ) 17,190 Insurance and REITs 18,304 150 (216 ) 18,238 Total financial services 55,765 397 (712 ) 55,450 Other corporate: Industrials 49,217 508 (761 ) 48,964 Utilities 24,895 292 (100 ) 25,087 Total other corporate 74,112 800 (861 ) 74,051 Total debt securities 162,311 1,323 (1,966 ) 161,668 Marketable equity securities: Mutual funds: Domestic community 3,216 25 (19 ) 3,222 Global asset allocation 42,396 48 (2,498 ) 39,946 Total marketable equity securities 45,612 73 (2,517 ) 43,168 Total securities available for sale $ 207,923 $ 1,396 $ (4,483 ) $ 204,836 The amortized cost and estimated fair value of securities available-for-sale and held-to-maturity, with gross unrealized gains and losses, follows: June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available-for-Sale: Marketable equity securities $ 9,437 $ 1,247 $ (247 ) $ 10,437 Securities Held-to-Maturity: Debt securities: U.S. Treasury $ 24,990 $ 1 $ — $ 24,991 Government-sponsored enterprises 32,672 6 (678 ) 32,000 Government-sponsored mortgage-backed and collateralized mortgage obligations 202,877 65 (1,737 ) 201,205 SBA asset-backed securities 23,133 — (200 ) 22,933 Total securities held to maturity $ 283,672 $ 72 $ (2,615 ) $ 281,129
Held-to-maturity Securities	The amortized cost and estimated fair value of securities available-for-sale and held-to-maturity, with gross unrealized gains and losses, follows: June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available-for-Sale: Marketable equity securities $ 9,437 $ 1,247 $ (247 ) $ 10,437 Securities Held-to-Maturity: Debt securities: U.S. Treasury $ 24,990 $ 1 $ — $ 24,991 Government-sponsored enterprises 32,672 6 (678 ) 32,000 Government-sponsored mortgage-backed and collateralized mortgage obligations 202,877 65 (1,737 ) 201,205 SBA asset-backed securities 23,133 — (200 ) 22,933 Total securities held to maturity $ 283,672 $ 72 $ (2,615 ) $ 281,129 Securities Held-to-Maturity: Debt securities: Government-sponsored enterprises $ 32,667 $ 4 $ (934 ) $ 31,737 Government-sponsored mortgage-backed and collateralized mortgage obligations 153,938 14 (1,806 ) 152,146 SBA asset-backed securities 14,422 — (212 ) 14,210 Total securities held to maturity $ 201,027 $ 18 $ (2,952 ) $ 198,093
Investments Classified by Contractual Maturity Date	The amortized cost and estimated fair value of debt securities by contractual maturity at June 30, 2017 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. Held to Maturity Amortized Cost Fair Value (In thousands) Within 1 year $ 29,993 $ 29,990 After 1 year through 5 years 9,689 9,534 After 5 years through 10 years 17,980 17,467 57,662 56,991 Mortgage- and asset-backed securities and collateralized mortgage obligations 226,010 224,138 $ 283,672 $ 281,129
Unrealized Gain (Loss) and Fair Value of Investments - Available-for-sale Securities	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: June 30, 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 $ (226 ) $ 4,533 $ (21 ) $ 446 Securities Held-to-Maturity: Debt securities: Government-sponsored enterprises $ (678 ) $ 27,867 $ — $ — Government-sponsored mortgage-backed and collateralized mortgage obligations (1,701 ) 189,308 (36 ) 3,448 SBA asset-backed securities (89 ) 14,648 (111 ) 8,285 Total temporarily impaired held-to-maturity securities $ (2,468 ) $ 231,823 $ (147 ) $ 11,733 December 31, 2016 Less Than Twelve Months More Than Twelve Months Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (In thousands) Securities Available-for-Sale: Debt securities: Mortgage- and other asset-backed securities: Privately issued commercial mortgage-backed securities $ (11 ) $ 3,163 $ (30 ) $ 7,326 Other asset-backed securities (43 ) 3,924 (152 ) 3,732 Total mortgage- and other asset-backed securities (54 ) 7,087 (182 ) 11,058 Municipal bonds (157 ) 5,301 — — Financial services: Banks (298 ) 14,553 — — Diversified financials (198 ) 9,369 — — Insurance and REITs (216 ) 6,900 — — Total financial services (712 ) 30,822 — — Other corporate: Industrials (655 ) 24,630 (106 ) 2,284 Utilities (99 ) 11,200 (1 ) 794 Total other corporate (754 ) 35,830 (107 ) 3,078 Total debt securities (1,677 ) 79,040 (289 ) 14,136 Marketable equity securities: Mutual funds: Domestic community — — (19 ) 448 Global asset allocation (424 ) 15,153 (2,074 ) 22,442 Total marketable equity securities (424 ) 15,153 (2,093 ) 22,890 Total temporarily impaired available-for-sale securities $ (2,101 ) $ 94,193 $ (2,382 ) $ 37,026
Unrealized Gain (Loss) and Fair Value of Investments - Held-to-maturity Securities	Securities Held-to-Maturity: Debt securities: Government-sponsored enterprises $ (934 ) $ 28,533 $ — $ — Government-sponsored mortgage-backed and collateralized mortgage obligations (1,763 ) 146,098 (43 ) 3,827 SBA asset-backed securities (104 ) 9,157 (108 ) 5,053 Total temporarily impaired held-to-maturity securities $ (2,801 ) $ 183,788 $ (151 ) $ 8,880 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: June 30, 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 $ (226 ) $ 4,533 $ (21 ) $ 446 Securities Held-to-Maturity: Debt securities: Government-sponsored enterprises $ (678 ) $ 27,867 $ — $ — Government-sponsored mortgage-backed and collateralized mortgage obligations (1,701 ) 189,308 (36 ) 3,448 SBA asset-backed securities (89 ) 14,648 (111 ) 8,285 Total temporarily impaired held-to-maturity securities $ (2,468 ) $ 231,823 $ (147 ) $ 11,733

Loans and The Allowance for L24

Loans and The Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	A summary of the balances of loans follows: June 30, December 31, 2017 2016 (In thousands) Real estate: 1-4 family residential $ 891,608 $ 851,154 Home equity 84,104 78,719 Commercial real estate 756,474 687,289 Construction 78,320 76,351 1,810,506 1,693,513 Commercial business 227,812 206,234 Consumer 24,786 29,281 Total loans 2,063,104 1,929,028 Allowance for loan losses (19,917 ) (18,750 ) Discount and fair value adjustments on purchased loans (1,694 ) (1,846 ) Deferred loan costs and fees, net 4,684 4,439 Loans, net $ 2,046,177 $ 1,912,871
Activity in Allowance for Loan Losses	Activity in the allowance for loan losses for the three and six months ended June 30, 2017 and 2016 , by loan segment, follows: 1-4 Family Home Commercial Construction Commercial Consumer Unallocated Total (In thousands) Three Months Ended June 30, 2017 Allowance at March 31, 2017 $ 5,000 $ 558 $ 8,333 $ 1,457 $ 3,126 $ 401 $ — $ 18,875 Provision (credit) for loan losses 25 51 654 153 226 9 — 1,118 Loans charged-off (52 ) — — — — (24 ) — (76 ) Recoveries — — — — — — — — Allowance at June 30, 2017 $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ — $ 19,917 Three Months Ended June 30, 2016 Allowance at March 31, 2016 $ 3,665 $ 617 $ 7,338 $ 1,622 $ 2,619 $ 699 $ 425 $ 16,985 Provision (credit) for loan losses 275 (78 ) 284 125 671 (192 ) 28 1,113 Loans charged-off — — — — (8 ) (11 ) — (19 ) Recoveries — — — — — — — — Allowance at June 30, 2016 $ 3,940 $ 539 $ 7,622 $ 1,747 $ 3,282 $ 496 $ 453 $ 18,079 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Unallocated Total (In thousands) Six Months Ended June 30, 2017 Allowance at December 31, 2016 $ 4,846 $ 537 $ 8,374 $ 1,353 $ 3,206 $ 434 $ — $ 18,750 Provision (credit) for loan losses 105 72 613 257 137 (9 ) — 1,175 Loans charged-off (52 ) — — — — (39 ) — (91 ) Recoveries 74 — — — 9 — — 83 Allowance at June 30, 2017 $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ — $ 19,917 Six Months Ended June 30, 2016 Allowance at December 31, 2015 $ 3,916 $ 636 $ 7,147 $ 1,364 $ 2,839 $ 772 $ 428 $ 17,102 Provision (credit) for loan losses 24 (97 ) 475 383 523 (247 ) 25 1,086 Loans charged-off — — — — (113 ) (29 ) — (142 ) Recoveries — — — — 33 — — 33 Allowance at June 30, 2016 $ 3,940 $ 539 $ 7,622 $ 1,747 $ 3,282 $ 496 $ 453 $ 18,079
Allowance for Credit Losses on Financing Receivables	Additional information pertaining to the allowance for loan losses at June 30, 2017 and December 31, 2016 is as follows: 1-4 Family Home Commercial Construction Commercial Consumer Unallocated Total (In thousands) June 30, 2017 Allowance related to impaired loans $ 32 $ — $ — $ — $ — $ — $ — $ 32 Allowance related to non-impaired loans 4,941 609 8,987 1,610 3,352 386 — 19,885 Total allowance for loan losses $ 4,973 $ 609 $ 8,987 $ 1,610 $ 3,352 $ 386 $ — $ 19,917 Impaired loans $ 6,277 $ 1,201 $ 5,024 $ — $ 177 $ 418 $ — $ 13,097 Non-impaired loans 885,331 82,903 751,450 78,320 227,635 24,368 — 2,050,007 Total loans $ 891,608 $ 84,104 $ 756,474 $ 78,320 $ 227,812 $ 24,786 $ — $ 2,063,104 December 31, 2016 Allowance related to impaired loans $ 17 $ — $ — $ — $ — $ — $ — $ 17 Allowance related to non-impaired loans 4,829 537 8,374 1,353 3,206 434 — 18,733 Total allowance for loan losses $ 4,846 $ 537 $ 8,374 $ 1,353 $ 3,206 $ 434 $ — $ 18,750 Impaired loans $ 6,726 $ 1,153 $ 941 $ — $ 241 $ 170 $ — $ 9,231 Non-impaired loans 844,428 77,566 686,348 76,351 205,993 29,111 — 1,919,797 Total loans $ 851,154 $ 78,719 $ 687,289 $ 76,351 $ 206,234 $ 29,281 $ — $ 1,929,028
Past Due Financing Receivables	The following is a summary of past due and non-accrual loans, by loan class, at June 30, 2017 and December 31, 2016 : 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) June 30, 2017 Real estate: 1-4 family residential $ 598 $ 653 $ 2,114 $ 3,365 $ 5,757 Home equity 674 14 572 1,260 1,201 Commercial real estate — — 4,126 4,126 5,024 Commercial business — — — — 177 Consumer 149 10 309 468 418 Total $ 1,421 $ 677 $ 7,121 $ 9,219 $ 12,577 December 31, 2016 Real estate: 1-4 family residential $ 584 $ 373 $ 2,322 $ 3,279 $ 6,478 Home equity 452 496 775 1,723 1,153 Commercial real estate 1,393 — — 1,393 941 Commercial business 4,996 13 — 5,009 241 Consumer 175 5 7 187 170 Total $ 7,600 $ 887 $ 3,104 $ 11,591 $ 8,983
Impaired Financing Receivables	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 June 30, 2017 (In thousands) Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 5,881 $ 6,085 $ — Home equity 1,201 1,305 — Commercial real estate 5,024 5,447 — Commercial business 177 287 — Consumer 418 425 — Total 12,701 13,549 — Impaired loans with a valuation allowance: 1-4 family residential 396 588 32 Total impaired loans $ 13,097 $ 14,137 $ 32 December 31, 2016 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 6,605 $ 7,023 $ — Home equity 1,153 1,225 — Commercial real estate 941 1,207 — Commercial business 241 3,279 — Consumer 170 183 — Total 9,110 12,917 — Impaired loans with a valuation allowance: 1-4 family residential 121 313 17 Total impaired loans $ 9,231 $ 13,230 $ 17 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 June 30, 2017 (In thousands) Real estate: 1-4 family residential $ 6,395 $ 82 Home equity 1,294 15 Commercial real estate 5,048 27 Commercial 200 2 Consumer 287 4 Total $ 13,224 $ 130 Three Months Ended June 30, 2016 Real estate: 1-4 family residential $ 6,508 $ 72 Home equity 381 4 Commercial real estate 4,819 38 Commercial 155 3 Consumer 1,519 — Total $ 13,382 $ 117 Six Months Ended June 30, 2017 Real estate: 1-4 family residential $ 6,505 $ 160 Home equity 1,247 29 Commercial real estate 3,679 35 Consumer 214 5 Commercial 249 5 Total $ 11,894 $ 234 Six Months Ended June 30, 2016 Real estate: 1-4 family residential $ 6,377 $ 145 Home equity 344 8 Commercial real estate 4,756 94 Consumer 151 5 Commercial 2,248 31 Total $ 13,876 $ 283
Financing Receivable Credit Quality Indicators	The following tables present the Company’s loans by risk rating at June 30, 2017 and December 31, 2016 : 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Total Loans (In thousands) June 30, 2017 Loans rated 1 - 6 $ 1,036 $ 283 $ 750,494 $ 78,320 $ 213,485 $ 4 $ 1,043,622 Loans rated 7 3,498 1,305 753 — 14,138 253 19,947 Loans rated 8 2,399 — 5,227 — 189 — 7,815 Loans rated 9 255 — — — — — 255 Loans rated 10 — — — — — — — Loans not rated 884,420 82,516 — — — 24,529 991,465 $ 891,608 $ 84,104 $ 756,474 $ 78,320 $ 227,812 $ 24,786 $ 2,063,104 December 31, 2016 Loans rated 1 - 6 $ 1,054 $ 293 $ 671,872 $ 76,351 $ 188,706 $ 4 $ 938,280 Loans rated 7 3,514 967 9,720 — 17,510 146 31,857 Loans rated 8 2,442 258 5,697 — 18 37 8,452 Loans rated 9 645 — — — — — 645 Loans rated 10 — — — — — — — Loans not rated 843,499 77,201 — — — 29,094 949,794 $ 851,154 $ 78,719 $ 687,289 $ 76,351 $ 206,234 $ 29,281 $ 1,929,028

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016 . Derivative Gains Derivative Losses Notional Amount Fair Value Notional Amount Fair Value (In thousands) June 30, 2017 Economic hedges: Commercial loan level interest rate swap agreements $ 495,404 $ 9,564 $ 495,404 $ 9,564 Other contracts 28,027 33 42,697 49 Total derivatives $ 523,431 $ 9,597 $ 538,101 $ 9,613 December 31, 2016 Economic hedges: Commercial loan level interest rate swap agreements $ 419,488 $ 9,016 $ 419,488 $ 8,932 Other contracts 15,685 8 33,045 56 Total derivatives $ 435,173 $ 9,024 $ 452,533 $ 8,988

Deposits (Tables)

Deposits (Tables)	6 Months Ended
	Jun. 30, 2017
Banking and Thrift [Abstract]
Schedule of Deposit Balances	A summary of deposit balances, by type, is as follows: June 30, December 31, 2017 2016 (In thousands) NOW and demand $ 359,877 $ 331,508 Regular savings 246,484 262,984 Money market 674,593 573,204 Brokered money market 44,728 53,357 Total non-certificate accounts 1,325,682 1,221,053 Term certificates of $250,000 or more 90,988 77,550 Term certificates less than $250,000 271,273 262,564 Brokered term certificates 277,320 247,520 Total term certificate accounts 639,581 587,634 Total deposits $ 1,965,263 $ 1,808,687
Schedule of Contractual Maturities of Deposits and Weighted Average Rate	At June 30, 2017 , the scheduled maturities of term certificate accounts, including brokered deposits, are as follows: Amount Weighted Average Rate (Dollars in thousands) Within 1 year $ 408,915 0.91 % 1-2 years 92,654 1.25 2-3 years 94,474 1.84 3-4 years 24,997 1.82 4 years and beyond 18,541 1.64 $ 639,581 1.15 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
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) June 30, 2017 Assets Securities available for sale: Marketable equity securities $ 10,437 $ — $ — $ 10,437 Derivative assets: Interest rate swap agreements — 9,597 — 9,597 Forward loan sale commitments — — 27 27 Mortgage loan commitments — — 707 707 Total assets $ 10,437 $ 9,597 $ 734 $ 20,768 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 9,604 $ — $ 9,604 Forward loan sale commitments — — 173 173 Mortgage loan commitments — — 24 24 Total liabilities $ — $ 9,604 $ 197 $ 9,801 December 31, 2016 Assets Securities available for sale: Debt securities $ — $ 161,668 $ — $ 161,668 Marketable equity securities 43,168 — — 43,168 Derivative assets: Interest rate swap agreements — 9,024 — 9,024 Forward loan sale commitments — — 15 15 Mortgage loan commitments — — 111 111 Total assets $ 43,168 $ 170,692 $ 126 $ 213,986 Liabilities Derivative liabilities: Interest rate swap agreements $ — $ 8,988 $ — $ 8,988 Forward loan sale commitments — — 74 74 Mortgage loan commitments — — 3 3 Total liabilities $ — $ 8,988 $ 77 $ 9,065
Fair Value Measurements, Nonrecurring	The following table summarizes the fair value hierarchy applicable to assets measured at fair value on a non-recurring basis: June 30, 2017 December 31, 2016 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 (In thousands) Impaired loans $ — $ — $ 573 $ — $ — $ 136 The following table summarizes the total losses on assets measured at fair value on a non-recurring basis for the three and six months ended June 30, 2017 and 2016 . Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (In thousands) Impaired loans $ (86 ) $ (528 ) $ (9 ) $ (307 )
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) June 30, 2017 Financial assets: Cash and cash equivalents $ 51,111 $ 51,111 $ — $ — $ 51,111 Securities available for sale 10,437 10,437 — — 10,437 Securities held to maturity 283,672 24,991 256,138 — 281,129 Federal Home Loan Bank stock 11,943 — — 11,943 11,943 Loans and loans held for sale 2,052,966 — — 2,044,096 2,044,096 Accrued interest receivable 5,362 — — 5,362 5,362 Financial liabilities: Deposits 1,965,263 — — 1,964,672 1,964,672 Borrowings 130,000 — 129,525 — 129,525 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 9,597 — 9,597 — 9,597 Forward loan sale commitments 27 — — 27 27 Mortgage loan commitments 707 — — 707 707 Derivative liabilities: Interest rate swap agreements 9,604 — 9,604 — 9,604 Forward loan sale commitments 173 — — 173 173 Mortgage loan commitments 24 — — 24 24 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) December 31, 2016 Financial assets: Cash and cash equivalents $ 30,496 $ 30,496 $ — $ — $ 30,496 Securities available for sale 204,836 43,168 161,668 — 204,836 Securities held to maturity 201,027 — 198,093 — 198,093 Federal Home Loan Bank stock 13,352 — — 13,352 13,352 Loans and loans held for sale 1,915,632 — — 1,903,978 1,903,978 Accrued interest receivable 6,057 — — 6,057 6,057 Financial liabilities: Deposits 1,808,687 — — 1,808,629 1,808,629 Borrowings 251,000 — 250,648 — 250,648 On-balance sheet derivative financial instruments: Derivative assets: Interest rate swap agreements 9,024 — 9,024 — 9,024 Forward loan sale commitments 15 — — 15 15 Mortgage loan commitments 111 — — 111 111 Derivative liabilities: Interest rate swap agreements 8,988 — 8,988 — 8,988 Forward loan sale commitments 74 — — 74 74 Mortgage loan commitments 3 — — 3 3

Comprehensive Income (Tables)

Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive loss, included in stockholders' equity, are as follows: June 30, December 31, 2017 2016 (In thousands) Securities available for sale: Net unrealized gain (loss) $ 1,000 $ (3,087 ) Tax effect (420 ) 1,007 Net-of-tax amount 580 (2,080 ) Securities held to maturity: Net unrealized gain on transferred securities 292 337 Tax effect (109 ) (114 ) Net-of-tax amount 183 223 Defined benefit pension plan: Unrecognized net actuarial loss (3,304 ) (3,482 ) Tax effect 1,180 1,270 Net-of-tax amount (2,124 ) (2,212 ) $ (1,361 ) $ (4,069 ) Changes in accumulated other comprehensive income (loss), by component, follow: Three Months Ended June 30, 2017 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at March 31, 2017 $ (159 ) $ 196 $ (2,182 ) $ (2,145 ) Other comprehensive income before reclassification adjustments 2,190 — — 2,190 Reclassification adjustments: Net realized gains (928 ) — — (928 ) Amortization of actuarial losses — — 89 89 Amortization of amounts previously recorded upon transfer from available-for-sale — (22 ) — (22 ) Tax effects (523 ) 9 (31 ) (545 ) Net current-period other comprehensive income (loss) 739 (13 ) 58 784 Balance at June 30, 2017 $ 580 $ 183 $ (2,124 ) $ (1,361 ) Three Months Ended June 30, 2016 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at March 31, 2016 $ (1,346 ) $ 329 $ (1,762 ) $ (2,779 ) Other comprehensive income before reclassification adjustments 3,512 — — 3,512 Reclassification adjustments: Net realized gains (664 ) — — (664 ) Amortization of actuarial losses — — 68 68 Amortization of amounts previously recorded upon transfer from available-for-sale — (79 ) — (79 ) Tax effects (994 ) 28 (24 ) (990 ) Net current-period other comprehensive income (loss) 1,854 (51 ) 44 1,847 Balance at June 30, 2016 $ 508 $ 278 $ (1,718 ) $ (932 ) Six Months Ended June 30, 2017 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at December 31, 2016 $ (2,080 ) $ 223 $ (2,212 ) $ (4,069 ) Other comprehensive income before reclassification adjustments 3,993 — — 3,993 Reclassification adjustments: Net realized losses 94 — — 94 Amortization of actuarial losses — — 178 178 Amortization of amounts previously recorded upon transfer from available-for-sale — (45 ) — (45 ) Tax effects (1,427 ) 5 (90 ) (1,512 ) Net current-period other comprehensive income (loss) 2,660 (40 ) 88 2,708 Balance at June 30, 2017 $ 580 $ 183 $ (2,124 ) $ (1,361 ) Six Months Ended June 30, 2016 Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total (In thousands) Balance at December 31, 2015 $ (3,756 ) $ 374 $ (1,806 ) $ (5,188 ) Other comprehensive income before reclassification adjustments 6,927 — — 6,927 Reclassification adjustments: Net realized gains (375 ) — — (375 ) Amortization of actuarial losses — — 136 136 Amortization of amounts previously recorded upon transfer from available-for-sale — (149 ) — (149 ) Tax effects (2,288 ) 53 (48 ) (2,283 ) Net current-period other comprehensive income (loss) 4,264 (96 ) 88 4,256 Balance at June 30, 2016 $ 508 $ 278 $ (1,718 ) $ (932 )

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016 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.: June 30, 2017 Total capital (to risk weighted assets) $ 408,048 21.2 % $ 154,065 8.0 % 192,581 10.0 % Tier 1 capital (to risk weighted assets) 388,131 20.2 115,548 6.0 154,065 8.0 Common equity Tier 1 (to risk weighted assets) 388,131 20.2 86,661 4.5 125,177 6.5 Tier 1 capital (to average assets) 388,131 15.6 99,437 4.0 124,297 5.0 December 31, 2016 Total capital (to risk weighted assets) $ 395,325 20.5 % $ 154,471 8.0 % 193,089 10.0 % Tier 1 capital (to risk weighted assets) 376,575 19.5 115,854 6.0 154,471 8.0 Common equity Tier 1 (to risk weighted assets) 376,575 19.5 86,890 4.5 125,508 6.5 Tier 1 capital (to average assets) 376,575 16.0 94,166 4.0 117,708 5.0 Blue Hills Bank: June 30, 2017 Total capital (to risk weighted assets) $ 332,170 17.3 % $ 153,789 8.0 % $ 192,237 10.0 % Tier 1 capital (to risk weighted assets) 312,253 16.2 115,342 6.0 153,789 8.0 Common equity Tier 1 (to risk weighted assets) 312,253 16.2 86,507 4.5 124,954 6.5 Tier 1 capital (to average assets) 312,253 12.4 100,714 4.0 125,893 5.0 December 31, 2016 Total capital (to risk weighted assets) $ 313,457 16.3 % $ 154,196 8.0 % $ 192,745 10.0 % Tier 1 capital (to risk weighted assets) 294,707 15.3 115,647 6.0 154,196 8.0 Common equity Tier 1 (to risk weighted assets) 294,707 15.3 86,735 4.5 125,284 6.5 Tier 1 capital (to average assets) 294,707 12.5 94,099 4.0 117,623 5.0

Employee Stock Ownership Plan (

Employee Stock Ownership Plan (Tables)	6 Months Ended
	Jun. 30, 2017
Retirement Benefits [Abstract]
Employee Stock Ownership Plan (ESOP) Disclosures	Shares held by the ESOP include the following: June 30, 2017 December 31, 2016 Allocated 223,469 149,613 Committed to be allocated 37,644 75,912 Unallocated 2,011,964 2,049,608 2,273,077 2,275,133

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Three Months Ended June 30, 2017 2016 (In thousands, except share amounts) Net income applicable to common stock $ 3,868 $ 1,358 Average number of common shares outstanding 26,859,345 27,678,337 Less: Average unallocated ESOP shares (2,021,427 ) (2,096,794 ) Less: Average unvested restricted stock awards (885,475 ) (1,006,332 ) Average number of common shares outstanding used to calculate basic earnings per common share 23,952,443 24,575,211 Effect of dilutive stock options 155,938 — Effect of dilutive unvested restricted stock awards 238,172 124,583 Average number of common shares outstanding used to calculate diluted earnings per common share 24,346,553 24,699,794 Earnings per common share: Basic $ 0.16 $ 0.06 Diluted $ 0.16 $ 0.05 Six Months Ended June 30, 2017 2016 (In thousands, except share amounts) Net income applicable to common stock $ 11,355 $ 3,025 Average number of common shares outstanding 26,851,143 27,914,044 Less: Average unallocated ESOP shares (2,030,786 ) (2,106,257 ) Less: Average unvested restricted stock awards (888,313 ) (990,527 ) Average number of common shares outstanding used to calculate basic earnings per common share 23,932,044 24,817,260 Effect of dilutive stock options 147,665 — Effect of dilutive unvested restricted stock awards 231,513 95,469 Average number of common shares outstanding used to calculate diluted earnings per common share 24,311,222 24,912,729 Earnings per common share: Basic $ 0.47 $ 0.12 Diluted $ 0.47 $ 0.12

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
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 six months ended June 30, 2017 . Options granted 372,100 Vesting period (years) 5 Term (years) 10 Expected volatility 27.20%-27.43% Expected life (years) 6.5 Expected dividend yield 0.71%-1.11% Risk free interest rate 2.02%-2.16% Fair value per option $4.88-$5.31
Schedule of Share-based Compensation, Stock Options, Activity	A summary of the status of the Company's stock option grants for the six months ended June 30, 2017 , 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, 2016 2,449,670 $ 14.06 — $ — Granted 372,100 18.23 — — Forfeited (150,500 ) 14.07 — — Exercised (15,660 ) 13.88 — 65,000 Outstanding at June 30, 2017 2,655,610 $ 14.65 8.47 $ 8,758,000 Exercisable at June 30, 2017 491,230 $ 14.07 8.28 $ 1,881,000 Unrecognized compensation cost inclusive of directors' options at June 30, 2017 $ 7,983,000 Weighted average remaining recognition period (years) 3.58
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 six months ended June 30, 2017 : Outstanding Restricted Stock Awards Weighted Average Grant Price Nonvested stock awards at December 31, 2016 816,070 $ 14.06 Granted 175,695 18.25 Vested (21,873 ) 14.01 Forfeited (84,417 ) 14.07 Nonvested stock awards at June 30, 2017 885,475 $ 14.89 Unrecognized compensation cost inclusive of directors' awards at June 30, 2017 $11,137,000 Weighted average remaining recognition period (years) 3.65

Basis of Presentation and Con33

Basis of Presentation and Consolidation (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Subsidiary or Equity Method Investee [Line Items]
Tax benefit from adoption of ASU	$ 2	$ 41
1-4 Family Residential
Subsidiary or Equity Method Investee [Line Items]
Origination covenants, maximum loan-to-value ratio (greater than) (percent)		80.00%
Retained earnings
Subsidiary or Equity Method Investee [Line Items]
Cumulative effect on change in accounting principle			$ (27)
ASU 2016-09 | Retained earnings
Subsidiary or Equity Method Investee [Line Items]
Cumulative effect on change in accounting principle			$ 27

Accounting Standards Updates (N

Accounting Standards Updates (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accounting Changes and Error Corrections [Abstract]
Future lease commitments	$ 23,500		$ 23,500
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in unrealized holding gains	$ 2,190	$ 3,512	3,993	$ 6,927
Pro Forma [Member] | Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in unrealized holding gains			$ 2,390

Securities - Available-for-sale

Securities - Available-for-sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Debt securities:
Amortized Cost		$ 162,311
Gross Unrealized Gains		1,323
Gross Unrealized Losses		(1,966)
Fair Value		161,668
Marketable equity securities:
Amortized Cost	$ 9,437	45,612
Gross Unrealized Gains	1,247	73
Gross Unrealized Losses	(247)	(2,517)
Fair Value	10,437	43,168
Available-for-sale securities:
Amortized Cost		207,923
Gross Unrealized Gains		1,396
Gross Unrealized Losses		(4,483)
Fair Value	$ 10,437	204,836
Total mortgage- and other asset-backed securities
Debt securities:
Amortized Cost		19,704
Gross Unrealized Gains		6
Gross Unrealized Losses		(236)
Fair Value		19,474
Privately issued commercial mortgage-backed securities
Debt securities:
Amortized Cost		10,530
Gross Unrealized Gains		0
Gross Unrealized Losses		(41)
Fair Value		10,489
Other asset-backed securities
Debt securities:
Amortized Cost		9,174
Gross Unrealized Gains		6
Gross Unrealized Losses		(195)
Fair Value		8,985
Municipal bonds
Debt securities:
Amortized Cost		12,730
Gross Unrealized Gains		120
Gross Unrealized Losses		(157)
Fair Value		12,693
Domestic community
Marketable equity securities:
Amortized Cost		3,216
Gross Unrealized Gains		25
Gross Unrealized Losses		(19)
Fair Value		3,222
Global asset allocation
Marketable equity securities:
Amortized Cost		42,396
Gross Unrealized Gains		48
Gross Unrealized Losses		(2,498)
Fair Value		39,946
Total other corporate | Corporate debt securities
Debt securities:
Amortized Cost		74,112
Gross Unrealized Gains		800
Gross Unrealized Losses		(861)
Fair Value		74,051
Industrials | Corporate debt securities
Debt securities:
Amortized Cost		49,217
Gross Unrealized Gains		508
Gross Unrealized Losses		(761)
Fair Value		48,964
Utilities | Corporate debt securities
Debt securities:
Amortized Cost		24,895
Gross Unrealized Gains		292
Gross Unrealized Losses		(100)
Fair Value		25,087
Total financial services | Corporate debt securities
Debt securities:
Amortized Cost		55,765
Gross Unrealized Gains		397
Gross Unrealized Losses		(712)
Fair Value		55,450
Banks | Corporate debt securities
Debt securities:
Amortized Cost		20,263
Gross Unrealized Gains		57
Gross Unrealized Losses		(298)
Fair Value		20,022
Diversified financials | Corporate debt securities
Debt securities:
Amortized Cost		17,198
Gross Unrealized Gains		190
Gross Unrealized Losses		(198)
Fair Value		17,190
Insurance and REITs | Corporate debt securities
Debt securities:
Amortized Cost		18,304
Gross Unrealized Gains		150
Gross Unrealized Losses		(216)
Fair Value		$ 18,238

Securities - Held-to-maturity S

Securities - Held-to-maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Debt securities:
Amortized Cost	$ 283,672	$ 201,027
Gross Unrealized Gains	72	18
Gross Unrealized Losses	(2,615)	(2,952)
Fair Value	281,129	198,093
U.S. Treasury
Debt securities:
Amortized Cost	24,990
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Fair Value	24,991
Government-sponsored enterprises
Debt securities:
Amortized Cost	32,672	32,667
Gross Unrealized Gains	6	4
Gross Unrealized Losses	(678)	(934)
Fair Value	32,000	31,737
Government-sponsored mortgage-backed and collateralized mortgage obligations
Debt securities:
Amortized Cost	202,877	153,938
Gross Unrealized Gains	65	14
Gross Unrealized Losses	(1,737)	(1,806)
Fair Value	201,205	152,146
SBA asset-backed securities
Debt securities:
Amortized Cost	23,133	14,422
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(200)	(212)
Fair Value	$ 22,933	$ 14,210

Securities - Schedule of Contra

Securities - Schedule of Contractual Maturities of Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis [Abstract]
Within 1 year, Held to Maturity, Amortized Cost	$ 29,993
After 1 year through 5 years, Held to Maturity, Amortized Cost	9,689
After 5 years through 10 years, Held to Maturity, Amortized Cost	17,980
Single Maturity Date, Held to Maturity, Amortized Cost	57,662
Mortgage- and asset-backed securities and collateralized mortgage obligations - Amortized Basis	226,010
Amortized Cost	283,672	$ 201,027
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value [Abstract]
Within 1 year, Held to Maturity, Fair Value	29,990
After 1 year through 5 years, Held to Maturity, Fair Value	9,534
After 5 years through 10 years, Held to Maturity, Fair Value	17,467
Single Maturity Date, Held to Maturity, Fair Value	56,991
Mortgage- and asset-backed securities and collateralized mortgage obligations - Fair Value	224,138
Held-to-maturity securities, total debt securities	$ 281,129	$ 198,093

Securities - Available-for-sa38

Securities - Available-for-sale Securities Unrealized Loss (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		$ (2,101)
Gross Unrealized Losses - More than twelve months		(2,382)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		94,193
Fair Value - More than twelve months		37,026
Total debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(1,677)
Gross Unrealized Losses - More than twelve months		(289)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		79,040
Fair Value - More than twelve months		14,136
Total mortgage- and other asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(54)
Gross Unrealized Losses - More than twelve months		(182)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		7,087
Fair Value - More than twelve months		11,058
Privately issued commercial mortgage-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(11)
Gross Unrealized Losses - More than twelve months		(30)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		3,163
Fair Value - More than twelve months		7,326
Other asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(43)
Gross Unrealized Losses - More than twelve months		(152)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		3,924
Fair Value - More than twelve months		3,732
Municipal bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(157)
Gross Unrealized Losses - More than twelve months		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		5,301
Fair Value - More than twelve months		0
Temporarily impaired marketable equity securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	$ (226)
Gross Unrealized Losses - More than twelve months	(21)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	4,533
Fair Value - More than twelve months	$ 446
Total marketable equity securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(424)
Gross Unrealized Losses - More than twelve months		(2,093)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		15,153
Fair Value - More than twelve months		22,890
Domestic community
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		0
Gross Unrealized Losses - More than twelve months		(19)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		0
Fair Value - More than twelve months		448
Global asset allocation
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(424)
Gross Unrealized Losses - More than twelve months		(2,074)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		15,153
Fair Value - More than twelve months		22,442
Total other corporate | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(754)
Gross Unrealized Losses - More than twelve months		(107)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		35,830
Fair Value - More than twelve months		3,078
Industrials | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(655)
Gross Unrealized Losses - More than twelve months		(106)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		24,630
Fair Value - More than twelve months		2,284
Utilities | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(99)
Gross Unrealized Losses - More than twelve months		(1)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		11,200
Fair Value - More than twelve months		794
Total financial services | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(712)
Gross Unrealized Losses - More than twelve months		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		30,822
Fair Value - More than twelve months		0
Banks | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(298)
Gross Unrealized Losses - More than twelve months		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		14,553
Fair Value - More than twelve months		0
Diversified financials | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(198)
Gross Unrealized Losses - More than twelve months		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		9,369
Fair Value - More than twelve months		0
Insurance and REITs | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(216)
Gross Unrealized Losses - More than twelve months		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		6,900
Fair Value - More than twelve months		$ 0

Securities - Held-to-maturity39

Securities - Held-to-maturity Securities Unrealized Loss (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	$ (2,468)	$ (2,801)
Gross Unrealized Losses - More than twelve months	(147)	(151)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	231,823	183,788
Fair Value - More than twelve months	11,733	8,880
Total mortgage- and other asset-backed securities
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(678)
Gross Unrealized Losses - More than twelve months	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	27,867
Fair Value - More than twelve months	0
Municipal bonds
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(1,701)
Gross Unrealized Losses - More than twelve months	(36)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	189,308
Fair Value - More than twelve months	3,448
Government-sponsored enterprises
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(934)
Gross Unrealized Losses - More than twelve months		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		28,533
Fair Value - More than twelve months		0
Government-sponsored mortgage-backed and collateralized mortgage obligations
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(1,763)
Gross Unrealized Losses - More than twelve months		(43)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		146,098
Fair Value - More than twelve months		3,827
SBA asset-backed securities
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(89)	(104)
Gross Unrealized Losses - More than twelve months	(111)	(108)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	14,648	9,157
Fair Value - More than twelve months	$ 8,285	$ 5,053

Securities - Narrative (Details

Securities - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)mutual_fund	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)mutual_fund	Jun. 30, 2016USD ($)
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sale of available-for-sale securities	$ 168,200	$ 44,700	$ 213,084	$ 60,194
Available-for-sale securities, gross realized gains	2,000	1,200	2,200	1,400
Available-for-sale securities, gross realized losses	$ (1,000)	$ (552)	$ (2,300)	$ (1,000)
Held-to-maturity securities, depreciation, percentage of amortized cost basis	1.00%		1.00%
Number of securities in loss positions | mutual_fund	2		2
Marketable equity securities
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	$ 247		$ 247
Available-for-sale securities, depreciation, percentage of amortized cost basis	4.70%		4.70%

Loans and The Allowance for L41

Loans and The Allowance for Loan Losses - Summary of Loan balances (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 2,063,104	$ 1,929,028
Allowance for loan losses	(19,917)	(18,750)
Discount and fair value adjustments on purchased loans	(1,694)	(1,846)
Deferred loan costs and fees, net	4,684	4,439
Loans, net	2,046,177	1,912,871
Consumer and Commercial Portfolio Segment | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	78,320	76,351
Consumer, Excluding Consumer Other Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,810,506	1,693,513
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	891,608	851,154
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	84,104	78,719
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	756,474	687,289
Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	227,812	206,234
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 24,786	$ 29,281

Loans and The Allowance for L42

Loans and The Allowance for Loan Losses - Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	$ 18,875	$ 16,985	$ 18,750	$ 17,102
Provision (credit) for loan losses	1,118	1,113	1,175	1,086
Loans charged-off	(76)	(19)	(91)	(142)
Recoveries	0	0	83	33
Loans and Leases Receivable, Ending Allowance	19,917	18,079	19,917	18,079
Unallocated
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	0	425	0	428
Provision (credit) for loan losses	0	28	0	25
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	0	453	0	453
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	5,000	3,665	4,846	3,916
Provision (credit) for loan losses	25	275	105	24
Loans charged-off	(52)	0	(52)	0
Recoveries	0	0	74	0
Loans and Leases Receivable, Ending Allowance	4,973	3,940	4,973	3,940
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	558	617	537	636
Provision (credit) for loan losses	51	(78)	72	(97)
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	609	539	609	539
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	8,333	7,338	8,374	7,147
Provision (credit) for loan losses	654	284	613	475
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	8,987	7,622	8,987	7,622
Consumer and Commercial Portfolio Segment | Construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	1,457	1,622	1,353	1,364
Provision (credit) for loan losses	153	125	257	383
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	1,610	1,747	1,610	1,747
Commercial business
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	3,126	2,619	3,206	2,839
Provision (credit) for loan losses	226	671	137	523
Loans charged-off	0	(8)	0	(113)
Recoveries	0	0	9	33
Loans and Leases Receivable, Ending Allowance	3,352	3,282	3,352	3,282
Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Beginning Allowance	401	699	434	772
Provision (credit) for loan losses	9	(192)	(9)	(247)
Loans charged-off	(24)	(11)	(39)	(29)
Recoveries	0	0	0	0
Loans and Leases Receivable, Ending Allowance	$ 386	$ 496	$ 386	$ 496

Loans and The Allowance for L43

Loans and The Allowance for Loan Losses - Additional Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	$ 32		$ 17
Allowance related to non-impaired loans	19,885		18,733
Total allowance for loan losses	19,917	$ 18,875	18,750	$ 18,079	$ 16,985	$ 17,102
Impaired loans	13,097		9,231
Non-impaired loans	2,050,007		1,919,797
Total loans	2,063,104		1,929,028
Unallocated
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		0
Allowance related to non-impaired loans	0		0
Total allowance for loan losses	0	0	0	453	425	428
Impaired loans	0		0
Non-impaired loans	0		0
Total loans	0		0
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	32		17
Allowance related to non-impaired loans	4,941		4,829
Total allowance for loan losses	4,973	5,000	4,846	3,940	3,665	3,916
Impaired loans	6,277		6,726
Non-impaired loans	885,331		844,428
Total loans	891,608		851,154
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	609		537
Total allowance for loan losses	609	558	537	539	617	636
Impaired loans	1,201		1,153
Non-impaired loans	82,903		77,566
Total loans	84,104		78,719
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	8,987		8,374
Total allowance for loan losses	8,987	8,333	8,374	7,622	7,338	7,147
Impaired loans	5,024		941
Non-impaired loans	751,450		686,348
Total loans	756,474		687,289
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	1,610		1,353
Total allowance for loan losses	1,610	1,457	1,353	1,747	1,622	1,364
Impaired loans	0		0
Non-impaired loans	78,320		76,351
Total loans	78,320		76,351
Commercial business
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		0
Allowance related to non-impaired loans	3,352		3,206
Total allowance for loan losses	3,352	3,126	3,206	3,282	2,619	2,839
Impaired loans	177		241
Non-impaired loans	227,635		205,993
Total loans	227,812		206,234
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0		0
Allowance related to non-impaired loans	386		434
Total allowance for loan losses	386	$ 401	434	$ 496	$ 699	$ 772
Impaired loans	418		170
Non-impaired loans	24,368		29,111
Total loans	$ 24,786		$ 29,281

Loans and The Allowance for L44

Loans and The Allowance for Loan Losses - Summary of Past Due and Non-accrual loans, by class (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 9,219	$ 11,591
Loans on Non-accrual	12,577	8,983
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,421	7,600
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	677	887
Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7,121	3,104
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,365	3,279
Loans on Non-accrual	5,757	6,478
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,260	1,723
Loans on Non-accrual	1,201	1,153
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,126	1,393
Loans on Non-accrual	5,024	941
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	598	584
Consumer, Excluding Consumer Other Portfolio Segment | 30-59 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	674	452
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	1,393
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	653	373
Consumer, Excluding Consumer Other Portfolio Segment | 60-89 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	14	496
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	2,114	2,322
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	572	775
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	4,126	0
Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	5,009
Loans on Non-accrual	177	241
Commercial business | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	4,996
Commercial business | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	13
Commercial business | Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	468	187
Loans on Non-accrual	418	170
Consumer | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	149	175
Consumer | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	10	5
Consumer | Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 309	$ 7

Loans and The Allowance for L45

Loans and The Allowance for Loan Losses - Summary of Impaired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Recorded Investment
Recorded Investment, without valuation allowance	$ 12,701	$ 9,110
Recorded Investment, total	13,097	9,231
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	13,549	12,917
Unpaid Principal Balance, total	14,137	13,230
Related Allowance	32	17
1-4 Family Residential
Recorded Investment
Recorded Investment, with a valuation allowance	396	121
Unpaid Principal Balance
Unpaid Principal Balance, with a valuation allowance	588	313
Related Allowance	32	17
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Recorded Investment
Recorded Investment, without valuation allowance	5,881	6,605
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	6,085	7,023
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Recorded Investment
Recorded Investment, without valuation allowance	1,201	1,153
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	1,305	1,225
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Recorded Investment
Recorded Investment, without valuation allowance	5,024	941
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	5,447	1,207
Commercial business
Recorded Investment
Recorded Investment, without valuation allowance	177	241
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	287	3,279
Consumer
Recorded Investment
Recorded Investment, without valuation allowance	418	170
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	$ 425	$ 183

Loans and The Allowance for L46

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 13,224	$ 13,382	$ 11,894	$ 13,876
Interest Income Recognized	130	117	234	283
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	6,395	6,508	6,505	6,377
Interest Income Recognized	82	72	160	145
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,294	381	1,247	344
Interest Income Recognized	15	4	29	8
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	5,048	4,819	3,679	4,756
Interest Income Recognized	27	38	35	94
Consumer
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	287	1,519	214	151
Interest Income Recognized	4	0	5	5
Commercial business
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	200	155	249	2,248
Interest Income Recognized	$ 2	$ 3	$ 5	$ 31

Loans and The Allowance for L47

Loans and The Allowance for Loan Losses - Summary of Loan by Risk Rating (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 2,063,104	$ 1,929,028
Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,043,622	938,280
Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	19,947	31,857
Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,815	8,452
Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	255	645
Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	991,465	949,794
Consumer, Excluding Consumer Other Portfolio Segment
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,810,506	1,693,513
Consumer, Excluding Consumer Other Portfolio Segment | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	891,608	851,154
Consumer, Excluding Consumer Other Portfolio Segment | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	84,104	78,719
Consumer, Excluding Consumer Other Portfolio Segment | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	756,474	687,289
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,036	1,054
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	283	293
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 1 - 6 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	750,494	671,872
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,498	3,514
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,305	967
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 7 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	753	9,720
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,399	2,442
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	258
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 8 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,227	5,697
Consumer, Excluding Consumer Other Portfolio Segment | Loans rated 9 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	255	645
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	884,420	843,499
Consumer, Excluding Consumer Other Portfolio Segment | Loans not rated | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	82,516	77,201
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	78,320	76,351
Consumer and Commercial Portfolio Segment | Loans rated 1 - 6 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	78,320	76,351
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	227,812	206,234
Commercial business | Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	213,485	188,706
Commercial business | Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,138	17,510
Commercial business | Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	189	18
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	24,786	29,281
Consumer | Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	4	4
Consumer | Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	253	146
Consumer | Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	37
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	$ 24,529	$ 29,094

Derivatives - Derivative Financ

Derivatives - Derivative Financial Instruments Not Designated as hedging Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Gains, notional amount	$ 523,431	$ 435,173
Derivative Gains, fair value	9,597	9,024
Derivative Losses, notional amount	538,101	452,533
Derivative Losses, fair value	9,613	8,988
Commercial loan level interest rate swap agreements
Derivatives, Fair Value [Line Items]
Derivative Gains, notional amount	495,404	419,488
Derivative Gains, fair value	9,564	9,016
Derivative Losses, notional amount	495,404	419,488
Derivative Losses, fair value	9,564	8,932
Other contracts
Derivatives, Fair Value [Line Items]
Derivative Gains, notional amount	28,027	15,685
Derivative Gains, fair value	33	8
Derivative Losses, notional amount	42,697	33,045
Derivative Losses, fair value	$ 49	$ 56

Derivatives - Additional Inform

Derivatives - Additional Information (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative Gains, fair value	$ 9,597	$ 9,024
Derivative Losses, fair value	9,613	8,988
Mortgage loan commitments
Derivative [Line Items]
Notional amount	48,600	6,800
Derivative Gains, fair value	707	111
Derivative Losses, fair value	24	3
Forward loan sale commitments
Derivative [Line Items]
Notional amount	55,300	9,500
Derivative Gains, fair value	27	15
Derivative Losses, fair value	$ 173	$ 74

Deposits - Summary of Deposit B

Deposits - Summary of Deposit Balances (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
NOW and demand	$ 359,877	$ 331,508
Regular savings	246,484	262,984
Money market	674,593	573,204
Brokered money market	44,728	53,357
Total non-certificate accounts	1,325,682	1,221,053
Term certificates of $250,000 or more	90,988	77,550
Term certificates less than $250,000	271,273	262,564
Brokered term certificates	277,320	247,520
Total term certificate accounts	639,581	587,634
Total deposits	$ 1,965,263	$ 1,808,687

Deposits - Schedule of Contract

Deposits - Schedule of Contractual Maturities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Amount
Amount - Within 1 year	$ 408,915
Amount - 1-2 years	92,654
Amount - 2-3 years	94,474
Amount - 3-4 years	24,997
Amount - 4 years and beyond	18,541
Total term certificate accounts	$ 639,581	$ 587,634
Weighted Average Rate
Weighted Average Rate - Within 1 year	0.91%
Weighted Average Rate - 1-2 years	1.25%
Weighted Average Rate - 2-3 years	1.84%
Weighted Average Rate - 3-4 years	1.82%
Weighted Average Rate - 4 years and beyond	1.64%
Weighted Average Rate	1.15%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Debt securities		$ 161,668
Marketable equity securities	$ 10,437	43,168
Recurring
Assets
Debt securities		161,668
Marketable equity securities	10,437	43,168
Total assets	20,768	213,986
Liabilities
Interest rate swap agreements	9,801	9,065
Recurring | Level 1
Assets
Debt securities		0
Marketable equity securities	10,437	43,168
Total assets	10,437	43,168
Liabilities
Interest rate swap agreements	0	0
Recurring | Level 2
Assets
Debt securities		161,668
Marketable equity securities	0	0
Total assets	9,597	170,692
Liabilities
Interest rate swap agreements	9,604	8,988
Recurring | Level 3
Assets
Debt securities		0
Marketable equity securities	0	0
Total assets	734	126
Liabilities
Interest rate swap agreements	197	77
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	9,597	9,024
Liabilities
Interest rate swap agreements	9,604	8,988
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	9,597	9,024
Liabilities
Interest rate swap agreements	9,604	8,988
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	9,597	9,024
Liabilities
Interest rate swap agreements	9,604	8,988
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 | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments | Level 3
Assets
Interest rate swap agreements	27	15
Liabilities
Interest rate swap agreements	173	74
Forward loan sale commitments | Recurring
Assets
Interest rate swap agreements	27	15
Liabilities
Interest rate swap agreements	173	74
Forward loan sale commitments | Recurring | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments | Recurring | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Forward loan sale commitments | Recurring | Level 3
Assets
Interest rate swap agreements	27	15
Liabilities
Interest rate swap agreements	173	74
Mortgage loan commitments | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments | Level 3
Assets
Interest rate swap agreements	707	111
Liabilities
Interest rate swap agreements	24	3
Mortgage loan commitments | Recurring
Assets
Interest rate swap agreements	707	111
Liabilities
Interest rate swap agreements	24	3
Mortgage loan commitments | Recurring | Level 1
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments | Recurring | Level 2
Assets
Interest rate swap agreements	0	0
Liabilities
Interest rate swap agreements	0	0
Mortgage loan commitments | Recurring | Level 3
Assets
Interest rate swap agreements	707	111
Liabilities
Interest rate swap agreements	$ 24	$ 3

Fair Value Measurements - Ass53

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ (86)	$ (528)	$ (9)	$ (307)
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0		$ 0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0		0		0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 573		$ 573		$ 136

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value, Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial assets:
Securities available for sale	$ 10,437	$ 204,836
Securities held to maturity	283,672	201,027
Estimate of Fair Value Measurement
Financial assets:
Cash and cash equivalents	51,111	30,496
Securities available for sale	10,437	204,836
Securities held to maturity	281,129	198,093
Federal Home Loan Bank stock	11,943	13,352
Loans and loans held for sale	2,044,096	1,903,978
Accrued interest receivable	5,362	6,057
Financial liabilities:
Deposits	1,964,672	1,808,629
Borrowings	129,525	250,648
Carrying Amount
Financial assets:
Cash and cash equivalents	51,111	30,496
Securities available for sale	10,437	204,836
Securities held to maturity	283,672	201,027
Federal Home Loan Bank stock	11,943	13,352
Loans and loans held for sale	2,052,966	1,915,632
Accrued interest receivable	5,362	6,057
Financial liabilities:
Deposits	1,965,263	1,808,687
Borrowings	130,000	251,000
Level 1
Financial assets:
Cash and cash equivalents	51,111	30,496
Securities available for sale	10,437	43,168
Securities held to maturity	24,991	0
Federal Home Loan Bank stock	0	0
Loans and loans held for sale	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
Securities available for sale	0	161,668
Securities held to maturity	256,138	198,093
Federal Home Loan Bank stock	0	0
Loans and loans held for sale	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	0	0
Borrowings	129,525	250,648
Level 3
Financial assets:
Cash and cash equivalents	0	0
Securities available for sale	0	0
Securities held to maturity	0	0
Federal Home Loan Bank stock	11,943	13,352
Loans and loans held for sale	2,044,096	1,903,978
Accrued interest receivable	5,362	6,057
Financial liabilities:
Deposits	1,964,672	1,808,629
Borrowings	0	0
Interest rate swap agreements | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	9,597	9,024
Derivative liabilities:	9,604	8,988
Interest rate swap agreements | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	9,597	9,024
Derivative liabilities:	9,604	8,988
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:	9,597	9,024
Derivative liabilities:	9,604	8,988
Interest rate swap agreements | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Forward loan sale commitments | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	27	15
Derivative liabilities:	173	74
Forward loan sale commitments | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	27	15
Derivative liabilities:	173	74
Forward loan sale commitments | Level 1
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Forward loan sale commitments | Level 2
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Forward loan sale commitments | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	27	15
Derivative liabilities:	173	74
Mortgage loan commitments | Estimate of Fair Value Measurement
On-balance sheet derivative financial instruments:
Derivative assets:	707	111
Derivative liabilities:	24	3
Mortgage loan commitments | Carrying Amount
On-balance sheet derivative financial instruments:
Derivative assets:	707	111
Derivative liabilities:	24	3
Mortgage loan commitments | Level 1
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Mortgage loan commitments | Level 2
On-balance sheet derivative financial instruments:
Derivative assets:	0	0
Derivative liabilities:	0	0
Mortgage loan commitments | Level 3
On-balance sheet derivative financial instruments:
Derivative assets:	707	111
Derivative liabilities:	$ 24	$ 3

Comprehensive Income - Componen

Comprehensive Income - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ (1,361)	$ (4,069)
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized actuarial gain (loss)	(3,304)	(3,482)
Tax effect	1,180	1,270
Accumulated other comprehensive income	(2,124)	(2,212)
Securities Available for Sale | Accumulated Net Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized actuarial gain (loss)	1,000	(3,087)
Tax effect	(420)	1,007
Accumulated other comprehensive income	580	(2,080)
Securities Held to Maturity | Accumulated Net Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized actuarial gain (loss)	292	337
Tax effect	(109)	(114)
Accumulated other comprehensive income	$ 183	$ 223

Comprehensive Income - Changes

Comprehensive Income - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance				$ 386,907	$ 398,829
Reclassification adjustments:
Amortization of amounts previously recorded upon transfer from available-for-sale	[1]	$ (22)	$ (79)	(45)	(149)
Other comprehensive income		784	1,847	2,708	4,256
Ending balance		397,318	391,952	397,318	391,952
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(2,145)	(2,779)	(4,069)	(5,188)
Other comprehensive income before reclassification adjustments		2,190	3,512	3,993	6,927
Reclassification adjustments:
Net realized gains		(928)	(664)	178	136
Amortization of actuarial losses		89	68	(45)
Amortization of amounts previously recorded upon transfer from available-for-sale		(22)	(79)	(1,512)	(149)
Tax effects		(545)	(990)	2,708	(2,283)
Other comprehensive income		784	1,847		4,256
Ending balance		(1,361)	(932)	(1,361)	(932)
Defined Benefit Pension Plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(2,182)	(1,762)	(2,212)	(1,806)
Other comprehensive income before reclassification adjustments		0	0	0	0
Reclassification adjustments:
Net realized gains		0	0	178	136
Amortization of actuarial losses		89	68	0
Amortization of amounts previously recorded upon transfer from available-for-sale		0	0	(90)	0
Tax effects		(31)	(24)	88	(48)
Other comprehensive income		58	44		88
Ending balance		(2,124)	(1,718)	(2,124)	(1,718)
Securities Available for Sale | Accumulated Net Investment Gain (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(159)	(1,346)	(2,080)	(3,756)
Other comprehensive income before reclassification adjustments		2,190	3,512	3,993	6,927
Reclassification adjustments:
Net realized gains		(928)	(664)	0	0
Amortization of amounts previously recorded upon transfer from available-for-sale		0	0	(1,427)	0
Tax effects		(523)	(994)	2,660	(2,288)
Other comprehensive income		739	1,854		4,264
Ending balance		580	508	580	508
Securities Held to Maturity | Accumulated Net Investment Gain (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		196	329	223	374
Other comprehensive income before reclassification adjustments		0	0	0	0
Reclassification adjustments:
Net realized gains		0	0	0	0
Amortization of amounts previously recorded upon transfer from available-for-sale		(22)	(79)	5	(149)
Tax effects		9	28	(40)	53
Other comprehensive income		(13)	(51)		(96)
Ending balance		$ 183	$ 278	$ 183	$ 278
[1]	Amounts are included in interest income on securities in the consolidated statements of net income.

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	Jan. 01, 2017	Dec. 31, 2016	Jan. 01, 2015
Equity [Abstract]
Tier one capital conservation buffer common equity capital to risk weighted assets (greater than)	1.25%	0.625%	2.50%

Stockholders' Equity - Minimum

Stockholders' Equity - Minimum Required Capital (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Total capital (to risk weighted assets)
Actual - Total Capital to Risk Weighted Assets	$ 408,048	$ 395,325
Actual - Total Capital to Risk Weighted Assets Ratio (percentage)	21.20%	20.50%
Minimum Capital Requirement - Total Capital	$ 154,065	$ 154,471
Minimum Capital Requirement - Total Capital to Risk Weighted Assets Ratio (percentage)	8.00%	8.00%
Minimum to Be Well Capitalized - Total Capital	$ 192,581	$ 193,089
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	$ 388,131	$ 376,575
Actual - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	20.20%	19.50%
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets	$ 115,548	$ 115,854
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	$ 154,065	$ 154,471
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	$ 388,131	$ 376,575
Actual - Common Equity to Risk Weighted Assets Ratio (percentage)	20.20%	19.50%
Minimum Capital Requirement - Common Equity to Risk Weighted Assets	$ 86,661	$ 86,890
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	$ 125,177	$ 125,508
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	$ 388,131	$ 376,575
Actual - Tier 1 Capital to Average Assets Ratio (percentage)	15.60%	16.00%
Minimum Capital Requirement - Tier 1 Capital to Average Assets	$ 99,437	$ 94,166
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	$ 124,297	$ 117,708
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	$ 332,170	$ 313,457
Actual - Total Capital to Risk Weighted Assets Ratio (percentage)	17.30%	16.30%
Minimum Capital Requirement - Total Capital	$ 153,789	$ 154,196
Minimum Capital Requirement - Total Capital to Risk Weighted Assets Ratio (percentage)	8.00%	8.00%
Minimum to Be Well Capitalized - Total Capital	$ 192,237	$ 192,745
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	$ 312,253	$ 294,707
Actual - Tier 1 Capital to Risk Weighted Assets Ratio (percentage)	16.20%	15.30%
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets	$ 115,342	$ 115,647
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	$ 153,789	$ 154,196
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	$ 312,253	$ 294,707
Actual - Common Equity to Risk Weighted Assets Ratio (percentage)	16.20%	15.30%
Minimum Capital Requirement - Common Equity to Risk Weighted Assets	$ 86,507	$ 86,735
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	$ 124,954	$ 125,284
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	$ 312,253	$ 294,707
Actual - Tier 1 Capital to Average Assets Ratio (percentage)	12.40%	12.50%
Minimum Capital Requirement - Tier 1 Capital to Average Assets	$ 100,714	$ 94,099
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	$ 125,893	$ 117,623
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	Jun. 30, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Allocated	223,469	149,613
Committed to be allocated	37,644	75,912
Unallocated	2,011,964	2,049,608
Total	2,273,077	2,275,133

Employee Stock Ownership Plan60

Employee Stock Ownership Plan - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Retirement Benefits [Abstract]
ESOP, Number of shares committed to be released annually (shares)	75,912		75,912
Fair Value of unallocated shares	$ 36,000		$ 36,000		$ 38,400
ESOP expense	$ 343	$ 276	$ 684	$ 541

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income applicable to common stock	$ 3,868	$ 1,358	$ 11,355	$ 3,025
Average number of common shares outstanding	26,859,345	27,678,337	26,851,143	27,914,044
Less: Average unallocated ESOP shares	(2,021,427)	(2,096,794)	(2,030,786)	(2,106,257)
Less: Average unvested restricted stock awards	(885,475)	(1,006,332)	(888,313)	(990,527)
Average number of common shares outstanding used to calculate basic earnings per common share	23,952,443	24,575,211	23,932,044	24,817,260
Average number of common shares outstanding used to calculate diluted earnings per common share	24,346,553	24,699,794	24,311,222	24,912,729
Earnings per common share:
Basic (dollars per share)	$ 0.16	$ 0.06	$ 0.47	$ 0.12
Diluted (dollars per share)	$ 0.16	$ 0.05	$ 0.47	$ 0.12
Antidilutive securities excluded from computation of earnings per share (shares)	372,100	2,462,350
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effect of dilutive share-based compensation awards (in shares)	155,938	0	147,665	0
Unvested Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Effect of dilutive share-based compensation awards (in shares)	238,172	124,583	231,513	95,469

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	2,846,681		2,846,681
Term (years)			10 years
Expected life (years)			6 years 6 months
Vesting period (years)			5 years
Share-based compensation expense	$ 568	$ 485	$ 1,178	$ 996
Tax benefit related to share-based compensation expense	$ 135	125	$ 290	250
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,138,673		1,138,673
Share-based compensation expense	$ 770	701	$ 1,567	1,385
Tax benefit related to share-based compensation expense	$ 269	$ 247	$ 574	$ 489
Granted (shares)			175,695
Vested (shares)			21,873
Nonvested (shares)	885,475		885,475		816,070
Forfeited (shares)			84,417
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)			40,000
Vested (shares)			6,000
Nonvested (shares)	32,000		32,000
Forfeited (shares)			2,000
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)	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (shares) | shares	372,100
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (shares) | shares	372,100
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)	27.20%
Expected dividend yield (percent)	0.71%
Risk free interest rate (percent)	2.02%
Fair value per option (dollars per share) | $ / shares	$ 4.88
Maximum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term (years)	10 years
Expected volatility (percent)	27.43%
Expected dividend yield (percent)	1.11%
Risk free interest rate (percent)	2.16%
Fair value per option (dollars per share) | $ / shares	$ 5.31

Share-Based Compensation - Stoc

Share-Based Compensation - Stock Option Activity (Details)	6 Months Ended
	Jun. 30, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (shares)	2,449,670
Granted (shares)	372,100
Forfeited (shares)	(150,500)
Exercised (shares)	(15,660)
Ending balance (shares)	2,655,610
Exercisable at end of period (shares)	491,230
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	$ 14.06
Granted, weighted average exercise price (dollars per share) | $ / shares	18.23
Forfeited, weighted average exercise price (dollars per share) | $ / shares	14.07
Exercised, weighted average exercise price (dollars per share) | $ / shares	13.88
Ending balance, weighted average exercise price (dollars per share) | $ / shares	14.65
Exercisable at end of period, weighted average exercise price (dollars per share) | $ / shares	$ 14.07
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted average remaining contractual term (years)	8 years 5 months 19 days
Exercised, aggregate intrinsic value | $	$ 65,000
Outstanding, aggregate intrinsic value | $	8,758,000
Exercisable, aggregate intrinsic value | $	$ 1,881,000
Exercisable at period end, weighted average remaining contractual term (years)	8 years 3 months 11 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted (shares)	372,100
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Unrecognized compensation cost | $	$ 7,983,000
Weighted average remaining recognition period (years)	3 years 6 months 29 days

Share-Based Compensation - Rest

Share-Based Compensation - Restricted Stock Activity (Details) - Restricted Stock $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (shares) | shares	816,070
Granted (shares) | shares	175,695
Vested (shares) | shares	(21,873)
Forfeited (shares) | shares	(84,417)
Ending balance (shares) | shares	885,475
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) | $ / shares	$ 14.06
Granted, weighted average exercise price (dollars per share) | $ / shares	18.25
Vested, weighted average exercise price (dollars per share) | $ / shares	14.01
Forfeited, weighted average exercise price (dollars per share) | $ / shares	14.07
Ending balance, weighted average exercise price (dollars per share) | $ / shares	$ 14.89
Unrecognized compensation cost inclusive of directors' fees | $	$ 11,137
Weighted average remaining recognition period (years)	3 years 7 months 24 days