Blue Hills Bancorp (BHBK) 10-K 9 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 04, 2016	Jun. 30, 2015
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-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		27,034,973
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 383,737,000

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$ 10,932	$ 15,345
Short-term investments	22,366	44,801
Total cash and cash equivalents	33,298	60,146
Securities available for sale, at fair value	231,690	416,447
Securities held to maturity, at amortized cost	200,141	0
Federal Home Loan Bank stock, at cost	13,567	11,702
Loans held for sale	12,877	14,591
Loans, net of allowance for loan losses of $17,102 in 2015 and $12,973 in 2014	1,523,275	1,132,914
Premises and equipment, net	20,015	18,788
Accrued interest receivable	5,344	4,433
Goodwill	9,160	9,160
Core deposit intangible	2,625	4,232
Net deferred tax asset	10,665	6,233
Bank-owned life insurance	31,626	30,595
Other assets	20,060	18,907
Assets	2,114,343	1,728,148
Deposits:
Non-interest bearing	153,155	123,392
Interest bearing	1,280,694	1,089,324
Total deposits	1,433,849	1,212,716
Short-term borrowings	205,000	40,000
Long-term debt	55,000	35,000
Accrued expenses and other liabilities	21,665	28,826
Total liabilities	$ 1,715,514	$ 1,316,542
Commitments and contingencies (Note 13)
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, 28,492,732 and 28,466,813 issued and outstanding at December 31, 2015 and 2014 respectively	276	285
Additional paid-in capital	269,078	281,035
Unearned compensation- ESOP	(21,255)	(22,014)
Retained earnings	155,918	149,723
Accumulated other comprehensive income (loss)	(5,188)	2,577
Total Stockholders' equity	398,829	411,606
Liabilities and Equity	$ 2,114,343	$ 1,728,148

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for loan losses	$ 17,102	$ 12,973
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	28,492,732	28,466,813
Common Stock, shares outstanding	28,492,732	28,466,813

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest and dividend income:
Interest and fees on loans	$ 45,342	$ 37,382	$ 21,876
Interest on securities	8,828	7,859	8,821
Dividends	4,068	3,894	2,329
Other	63	140	66
Total interest and dividend income	58,301	49,275	33,092
Interest expense:
Interest on deposits	7,527	5,750	6,803
Interest on borrowings	1,217	1,148	1,168
Total interest expense	8,744	6,898	7,971
Net interest and dividend income	49,557	42,377	25,121
Provision for loan losses	4,090	3,381	4,094
Net interest income, after provision for loan losses	45,467	38,996	21,027
Noninterest income:
Total other than temporary impairment losses	0	(307)	(92)
Portion of impairment losses on debt securities recognized in other comprehensive income	0	0	0
Net impairment losses recognized in earnings	0	(307)	(92)
Deposit account fees	1,314	1,313	579
Interchange and ATM fees	1,511	1,397	821
Mortgage banking	282	784	1,290
Loan level derivative fee income	2,120	660	1,392
Gains on sales and calls of securities, net	1,968	2,822	5,091
Gains on trading assets, net	0	25	505
Bank-owned life insurance income	1,031	1,006	1,023
Bank-owned life insurance death benefit gains	0	182	1,872
Pension curtailment gain	0	1,304	0
Miscellaneous	453	421	530
Total noninterest income	8,679	9,607	13,011
Noninterest expense:
Salaries and employee benefits	22,570	21,308	16,903
Occupancy and equipment	6,267	5,305	3,996
Data processing	3,510	2,989	1,934
Professional fees	2,689	3,551	3,348
Advertising	2,458	2,427	1,823
FDIC deposit insurance	999	1,266	520
Directors’ fees	644	486	688
Amortization of core deposit intangible	1,607	1,808	0
Charitable foundation contribution	0	7,000	120
Other general and administrative	3,338	3,268	2,327
Total noninterest expense	44,082	49,408	31,659
Income (loss) before income taxes	10,064	(805)	2,379
Provision (benefit) for income taxes	2,837	(622)	(284)
Net income (loss)	$ 7,227	$ (183)	$ 2,663
Earnings per common share:
Basic earnings per share (dollars per share)	$ 0.28
Diluted earnings per share (dollars per share)	$ 0.28
Weighted average shares outstanding:
Weighted average common shares (basic) (shares)	26,064,947
Weighted average common shares (diluted) (shares)	26,069,589

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)		$ 7,227	$ (183)	$ 2,663
Securities available for sale:
Change in unrealized holding gains (losses)		(8,332)	4,942	(9,256)
Reclassification adjustment for net gains realized in net income	[1]	(1,968)	(2,515)	(4,999)
Reclassification of unrealized gains on securities transferred to held to maturity		(666)	0	0
Net unrealized gains (losses)		(10,966)	2,427	(14,255)
Tax effect		3,818	(1,018)	5,433
Net-of-tax amount		(7,148)	1,409	(8,822)
Reclassification of unrealized gains on securities transferred from available-for-sale		666	0	0
Amortization of amounts previously recorded upon transfer from available-for-sale	[2]	(95)	0	0
Net change in unrealized gains		571	0	0
Tax effect		(197)	0	0
Net-of-tax amount		374	0	0
Defined benefit pension plan:
Gains (losses) arising during the period		(1,610)	(2,090)	2,033
Reclassification adjustments for losses (gains) recognized in net periodic benefit cost	[3]	110	(70)	104
Net gains (losses)		(1,500)	(2,160)	2,137
Tax effect		509	863	(853)
Net-of-tax amount		(991)	(1,297)	1,284
Other comprehensive income (loss)		(7,765)	112	(7,538)
Comprehensive loss		$ (538)	$ (71)	$ (4,875)
[1]	Amounts are included in gains on sales and calls of securities and net impairment losses, net in noninterest income in the consolidated statements of operations. Income tax expense associated with the reclassification adjustment for the years ended December 31, 2015, 2014 and 2013 was approximately $691,000, $940,000 and $1,680,000, respectively.
[2]	(2)Amounts are included in interest income on securities in the consolidated statements of operations. Income tax expense associated with the amortization amount for the year ended December 31, 2015 was $35,000.
[3]	Amounts are included in salaries and employee benefits, in noninterest expense in the consolidated statements of operations. Income tax expense (benefit) associated with the reclassification adjustment for the years ended December 31, 2015, 2014 and 2013 were $(37,000), $24,000 and $(35,000), respectively.

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Reclassification adjustment for net gains realized in net income, tax	$ 691	$ 940	$ 1,680
Other comprehensive (income) loss, amortization adjustment from AOCI, held-to-maturities, tax	35
Other comprehensive income (loss), reclassification adjustment and other postretirement benefit plans, for net gain (loss), tax expense (benefit)	$ (37)	$ 24	$ (35)

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	SBLF Preferred Stock	Common Stock	Additional paid-in capital	Unearned Compensation- ESOP	Retained Earnings	Accumulated Other Comprehensive Income	IPO	IPOCommon Stock	IPOAdditional paid-in capital	Private Placement	Private PlacementCommon Stock	Private PlacementAdditional paid-in capital
Beginning balance at Dec. 31, 2012	$ 176,938	$ 18,724	$ 0	$ 0	$ 0	$ 148,211	$ 10,003
Beginning balance (in shares) at Dec. 31, 2012			0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(4,875)					2,663	(7,538)
Preferred stock dividends declared	(529)					(529)
Ending balance at Dec. 31, 2013	171,534	18,724	$ 0	0	0	150,345	2,465
Ending balance (in shares) at Dec. 31, 2013			0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(71)					(183)	112
Preferred stock dividends declared	(439)					(439)
Issuance of common stock								$ 274,143	$ 278	$ 273,865	$ 6,943	$ 7	$ 6,936
Issuance of common stock (in shares)									27,772,500			694,313
Stock purchased by the ESOP	(22,773)				(22,773)
ESOP shares committed to be released	993			234	759
Redemption of SBLF preferred stock	(18,724)	(18,724)
Ending balance at Dec. 31, 2014	411,606	0	$ 285	281,035	(22,014)	149,723	2,577
Ending balance (in shares) at Dec. 31, 2014			28,466,813
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(538)					7,227	(7,765)
Preferred stock dividends declared	0
ESOP shares committed to be released	1,063			304	759
Common stock dividends declared ($0.04 per share)	(1,032)					(1,032)
Repurchase of common stock	(13,121)		$ (10)	(13,111)
Repurchase of common stock (in shares)			(929,300)
Share redemption for tax withholdings on deferred compensation obligation	(439)			(439)
Share redemption for tax withholdings on deferred compensation obligation (in shares)			(27,956)
Restricted stock awards granted			$ 1	(1)
Restricted stock awards issued (in shares)			983,175
Stock based compensation expenses	1,124			1,124
Tax benefit from deferred compensation obligation	166			166
Ending balance at Dec. 31, 2015	$ 398,829	$ 0	$ 276	$ 269,078	$ (21,255)	$ 155,918	$ (5,188)
Ending balance (in shares) at Dec. 31, 2015			28,492,732

Consolidated Statements of Cha8

Consolidated Statements of Changes in Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / shares
Common stock dividends declared (dollars per share) | $ / shares	$ 0.04
IPO | Common Stock
IPO Expenses | $	$ 3,583

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ 7,227	$ (183)	$ 2,663
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Provision for loan losses	4,090	3,381	4,094
Net amortization of securities	3,710	2,184	14,112
Gains on sales and calls of securities, net	(1,968)	(2,822)	(5,091)
Impairment losses on securities	0	307	92
Proceeds from sale of loans	31,710	14,315	24,995
Loans originated for sale	(31,802)	(13,282)	(25,050)
Gains on sale of loans, net	(238)	(708)	(1,246)
Net amortization of deferred loan origination costs and discounts	100	(336)	595
Depreciation and amortization of premises and equipment	1,824	1,475	1,449
Issuance of common stock to charitable foundation	0	6,943	0
Amortization of core deposit intangible	1,607	1,808	0
Bank-owned life insurance income	(1,031)	(1,188)	(2,895)
ESOP expense	1,063	993	0
Pension curtailment gain	0	(1,304)	0
Deferred income tax benefit	(302)	(3,557)	(1,416)
Stock based compensation expense	1,124	0	0
Excess tax benefit from SERP	166	0	0
Net change in:
Trading assets	0	750	(266)
Accrued interest receivable	(911)	161	1,131
Other assets	(1,153)	(7,033)	(824)
Accrued expenses and other liabilities	(8,661)	14,220	3,966
Net cash provided by operating activities	6,555	16,124	16,309
Activity in securities available for sale:
Purchases	(153,222)	(367,511)	(335,943)
Sales	99,522	362,941	314,947
Maturities/calls	5,632	9,615	11,616
Principal paydowns	24,487	22,572	78,442
Activity in securities held to maturity:
Purchases	(23,361)	0	0
Maturities/calls	9,000	0	0
Principal paydowns	10,421	0	0
Loan (originations and purchases) net of paydowns	(400,115)	(315,872)	(307,845)
Proceeds from portfolio loan sales	7,608	27,810	27,317
Net purchases of premises and equipment	(3,051)	(2,023)	(1,050)
Purchases of FHLBB stock	(3,296)	(936)	(1,481)
Redemption of FHLBB stock	1,431	0	384
Proceeds from bank-owned life insurance	0	424	6,408
Cash provided by business combination, net of purchase price	0	151,587	0
Net cash used in investing activities	(424,944)	(111,393)	(207,205)
Cash flows from financing activities:
Net change in deposits, excluding brokered	124,670	32,644	17,723
Net change in brokered deposits	96,463	(9,752)	79,623
Net change in short-term borrowings	165,000	(130,000)	60,576
Repayments of long-term debt	0	(10,000)	0
Proceeds from long-term debt	20,000	0	0
Net proceeds from issuance of common stock	0	274,143	0
Acquisition of common stock by ESOP	0	(22,773)	0
Redemption of SBLF preferred stock	0	(18,724)	0
Preferred stock dividends paid	0	(439)	(529)
Repurchase of common stock	(13,121)	0	0
Share redemption for tax withholdings on deferred compensation obligation	(439)	0	0
Common stock dividends paid	(1,032)	0	0
Net cash provided by financing activities	391,541	115,099	157,393
Net change in cash and cash equivalents	(26,848)	19,830	(33,503)
Cash and cash equivalents at beginning of year	60,146	40,316	73,819
Cash and cash equivalents at end of year	33,298	60,146	40,316
Supplementary information:
Interest paid	8,700	6,921	7,923
Income taxes paid, net of refunds	4,280	257	3,292
Securities transferred from available-for-sale to held-to-maturity	196,958	0	0
Preferred stock dividends declared	0	439	529
Fair value of non-cash assets acquired	0	123,733	0
Fair value of liabilities assumed	0	275,320	0
Portfolio loans transferred to loans held for sale designation	$ 11,222	$ 14,591	$ 0

Basis of Presentation and Conso

Basis of Presentation and Consolidation	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Consolidation	BASIS OF PRESENTATION AND CONSOLIDATION Conversion Blue Hills Bancorp, Inc. (the “Company”) is a Maryland corporation formed in February 2014 for the purpose of becoming the holding company for Blue Hills Bank (the “Bank”) concurrent with the conversion of Hyde Park Bancorp, MHC from the mutual holding company to the stock holding company form of organization on July 21, 2014. In connection with the conversion, the Bank became a wholly-owned subsidiary of the Company and the Company sold 27,772,500 shares of its common stock, at $10.00 per share, for gross offering proceeds of approximately $277,725,000 , including the sale of 2,277,345 shares to the employee stock ownership plan (“ESOP”) for $22,773,450 . The purchase of common stock by the ESOP was financed by a loan from Blue Hills Funding Corporation ("the Funding Corporation"), a subsidiary of the Company. Upon the completion of the conversion, Hyde Park Bancorp, MHC and the Bank’s former Massachusetts chartered mid-tier holding company, Hyde Park Bancorp, Inc., ceased to exist. In connection with the plan of conversion, the Company established the Blue Hills Bank Foundation (the “Foundation”). The Foundation was funded with $7.0 million , including 694,313 shares of the Company’s common stock and $57,000 in cash, which was recorded as an expense by the Company in July 2014. At the time of conversion, the Company substantially restricted retained earnings by establishing a liquidation account and the Bank established a parallel liquidation account. The liquidation accounts amounted to $80.7 million and $135.7 million at December 31, 2015 and 2014 respectively, and are maintained for the benefit of eligible deposit account holders who continue to maintain their accounts at the Bank after the conversion. The liquidation accounts will be reduced annually to the extent that eligible account holders have reduced their qualifying deposits. Subsequent increases will not restore an eligible account holder’s interest in the liquidation accounts. In the event of a complete liquidation of the Bank, each account holder will be entitled to receive a distribution from the liquidation accounts as described in the Plan of Conversion. Neither the Company nor the Bank may declare or pay a cash dividend on its common stock if such dividend would cause its regulatory capital to be reduced below the amount required to maintain its respective liquidation account. Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries, Blue Hills Funding Corporation and the Bank, the principal operating entity and its wholly-owned subsidiaries, B.H. Security Corporation and HP Security Corporation, which are Massachusetts security corporations, and 1196 Corporation, which holds a restricted stock. All significant intercompany balances and transactions have been eliminated in consolidation. Prior to the the establishment of the Foundation in 2014, the Company established Blue Hills Bank Charitable Foundation, (the "Charitable Foundation"), a not-for-profit organization, to provide charitable contributions within the Company’s surrounding communities. Neither the Foundation or Charitable Foundation are subsidiaries of the Company. Business The Company provides a variety of financial services to individuals and businesses online and through its offices in Brookline, Dedham, Hyde Park, Milton, Nantucket, Norwood, West Roxbury, and Westwood Massachusetts. Its primary deposit products are checking, savings, money market and term certificate accounts and its primary lending products are residential mortgage loans, home equity loans, commercial real estate loans, commercial business loans and consumer loans. Use of estimates In preparing consolidated financial statements in conformity with accounting principles generally accepted in the United States of America, 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 realizability of deferred tax assets. Cash and cash equivalents For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash on hand, balances due from banks, and short-term investments comprised of federal funds sold, money-market mutual funds, and interest-bearing deposits, all of which mature within ninety days. The Company normally maintains balances on deposit with other financial institutions in excess of the federally insured limit. Restrictions on cash and due from banks The Company is required to maintain average balances on hand or with the Federal Reserve Bank (“FRB”). At December 31, 2015 and 2014 , these reserve balances amounted to $4.0 million and $28.1 million , respectively. Fair value hierarchy The Company groups its assets and liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. Level 1 - Valuation is based on quoted prices in active markets for identical assets or liabilities. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities Level 2 - Valuation is based on observable inputs other than Level 1 prices, such as quoted prices for similar assets and liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets and liabilities. Level 3 - Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include those whose value is determined using unobservable inputs to pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. Securities Debt securities that management has the positive intent and ability to hold to maturity are classified as “held to maturity” and recorded at amortized cost. Securities not classified as held to maturity, including equity securities with readily determinable fair values, are classified as “available for sale” and recorded at fair value, with unrealized gains and losses excluded from earnings and reported in other comprehensive income. Purchase premiums and discounts are recognized in interest income using the interest method over the terms of the securities. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. At least quarterly, and more frequently when warranted by economic or market conditions, management evaluates all securities with a decline in fair value below the amortized cost of the investment to determine whether or not the impairment is deemed to be other-than-temporary (OTTI). OTTI is required to be recognized if: (1) the Company intends to sell the security; (2) it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis; or (3) for debt securities, the present value of expected cash flows is not sufficient to recover the entire amortized cost basis. For all impaired debt securities that the Company intends to sell, or more likely than not will be required to sell, the full amount of the depreciation is recognized as OTTI through earnings. Credit-related OTTI for all other impaired debt securities is recognized through earnings. Non-credit related OTTI for such debt securities is recognized in other comprehensive income, net of applicable taxes. Marketable equity securities are evaluated for OTTI based on the severity and duration of the impairment and, if deemed to be other than temporary, the declines in fair value are reflected in earnings as realized losses. Federal Home Loan Bank stock The Company, as a member of the Federal Home Loan Bank of Boston (FHLBB) system, is required to maintain an investment in capital stock of the FHLBB. Based on the redemption provisions of the FHLBB, the stock has no quoted market value and is carried at cost. At its discretion, the FHLBB may declare dividends on the stock. The Company reviews its investment for impairment based on the ultimate recoverability of the cost basis in the FHLBB stock. As of December 31, 2015 and 2014 , no impairment has been recognized. Loans held for sale Loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Net unrealized losses, if any, are recognized through a valuation allowance by charges to income. Loans 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 and any deferred fees and costs on originated and 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 and to reverse all interest previously accrued against interest income. Past due status is based on contractual terms of the loan. The interest on non-accrual loans is accounted for on the cash-basis until qualifying for return to accrual. Loans are returned to accrual status when all the principal and interest amounts contractually due have been current for six consecutive months and future payments are reasonably assured. Allowance for loan losses The allowance for loan losses is based on the size and the composition of the loan portfolio, delinquency levels, loss experience, economic conditions and other factors related to the collectability of the loan portfolio. For portfolios for which the Company had no prior loss experience, the national peer group losses for relevant portfolios generally over the years 2007-2014 were used. Charge-off factors are updated at least quarterly and management assesses them quantitatively on a quarterly basis. 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; however, because of the increase in risk exposures new to the Company, 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 extrapolated historical loss experience based on FDIC data for depository institutions with assets of $1 billion to $5 billion for periods ranging from 2007-2014, 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 regional 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 1 st or 2 nd 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 primarily include investment real estate and are generally secured by assignments of leases, real estate collateral and guarantees from sponsors or owners. 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 are adversely impacted by a downturn in the economy as evidenced by increased vacancy rates, which in turn, will 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 speculative real estate development loans for which payment is derived from 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 debt. 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 classic and collector automobile loans. A significant portion of the classic and collector automobile loan portfolio is comprised of geographically diverse loans originated by and purchased from a third party, who also provides collection services. While this portfolio generated minimal charge-offs, the provisions for loan losses reflect management’s estimate of inherent losses based on a review of regional and national historical losses of other institutions with similar portfolios. Allocated component The allocated component relates to loans that are on the watch list (non-accruing loans, partially charged-off non-accruing loans and accruing adversely-rated loans) and 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. 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 An unallocated component is maintained to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance reflects the margin of imprecision inherent in the underlying assumptions used in the methodologies for estimating allocated and general reserves in the portfolio. Premises and equipment Land is carried at cost. Buildings, leasehold improvements and equipment are stated at cost, less accumulated depreciation and amortization, computed on the straight-line method over the estimated useful lives of the assets or the expected terms of the leases, if shorter. Expected terms include lease option periods to the extent that the exercise of such options is reasonably assured. Goodwill and identifiable intangible assets Goodwill is the price paid in excess of the fair value of net assets acquired and is not amortized. Goodwill is evaluated for impairment at least annually, or more often if warranted, using a combined qualitative and quantitative impairment approach. The initial qualitative approach assesses whether the existence of events or circumstances led to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events and circumstances, the Company determines it is more likely than not that the fair value is less than carrying value, the two step quantitative impairment test is performed. Step one of the quantitative impairment test compares book value to the fair value of the reporting unit. If test one is failed, a more detailed analysis is performed, which involves measuring the excess of the fair value of the reporting unit, as determined in step one, over the aggregate fair value of the individual assets, liabilities, and identifiable intangibles as if the reporting unit was being acquired in a business combination. Identifiable intangible assets subject to amortization consist of the core deposit intangible acquired in the acquisition of Nantucket Bank which has an estimated life of approximately 5.5 years. Identifiable intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. The core deposit intangible is being amortized using the sum of the years' digits method over its estimated life. Information related to the core deposit intangible, including the estimated annual amortization expense, is summarized below: (In thousands) Balance at December 31, 2013 $ — Acquisition of Nantucket Bank 6,040 Amortization (1,808 ) Balance at December 31, 2014 4,232 Amortization (1,607 ) Balance at December 31, 2015 $ 2,625 Estimated amortization expense for the years ending December 31, 2016 $ 1,225 2017 843 2018 461 2019 96 Total remaining $ 2,625 Bank-owned life insurance Bank-owned life insurance policies are reflected on the consolidated balance sheets at cash surrender value. Changes in cash surrender value are reflected in noninterest income in the consolidated statements of operations. Non-marketable investments The aggregate carrying amount of all cost and equity method investments included in other assets at December 31, 2015 and 2014 is $ 8.7 million and $ 6.1 million , respectively. The fair values of these investments are not readily available and are not evaluated for impairment unless there are identified events or changes in circumstances that may have a significant adverse effect on the fair value of the investments. Interest rate swap agreements For asset/liability management purposes, the Company periodically uses interest rate swap agreements to hedge various exposures or to modify interest rate characteristics of various balance sheet accounts. All interest rate swap agreements are recorded at fair value. Depending upon the intended use for the interest rate swap at inception, the Company designates the derivative as either an economic hedge of an asset or liability or a hedging instrument subject to the hedge accounting provisions. If the interest rate swap is not designated in a hedge relationship, gains or losses reflecting changes in fair value are recorded in earnings. Certain interest rate swap contracts are utilized to help commercial loan borrowers manage their interest rate risk. The interest rate swap contracts with commercial loan borrowers allow the borrowers to convert floating rate loan payments to fixed rate payments. When the Company enters into an interest rate swap contract with a commercial loan borrower, the Company concurrently enters into a matching interest rate swap with a correspondent bank counterparty in order to minimize interest rate risk to the Company. These interest rate derivative instruments are recorded on the consolidated balance sheets as either an asset or liability measured at fair value. These derivatives do not qualify for hedge accounting. As such, all changes in fair value of these derivative instruments are included in miscellaneous income. The Company pays and receives fees for entering into these contracts. The net fees are recognized in loan level derivative income when received. Transfers of financial assets Transfers of an entire financial asset, a group of entire financial assets, or a participating interest in an entire financial asset are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. During the normal course of business, the Company may transfer a portion of a financial asset, for example, a participation loan. In order to be eligible for sales treatment, the transfered portion of the loan must meet the criteria of a participating interest. If it does not meet the criteria of a participating interest, the transfer must be accounted for as a secured borrowing. In order to meet the criteria for a participating interest, all cash flows from the loan must be divided proportionately, the rights of each loan holder must have the same priority, the loan holders must have no recourse to the transferor other than standard representations and warranties and no loan holder has the right to pledge or exchange the entire loan. Retirement plan The Company accounts for its defined benefit pension plan using an actuarial model that allocates pension costs over the service period of employees in the plan. The Company accounts for the over-funded or under-funded status of its defined benefit plan as an asset or liability on its consolidated balance sheets and recognizes changes in the funded status that are not reflected in net periodic pension cost as other comprehensive income or loss. The Company amended its defined benefit pension plan in 2013 freezing the plan to new participants and subsequently amended the plan and froze it for all participants effective October 31, 2014. 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. Dividend rights on unvested options/awards are forfeitable, therefor unvested awards/options are not considered outstanding in the computation of basic earnings per share. Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued, as well as any adjustment to income that would result from the assumed issuance. Potential common shares that may be issued by the Company relate to outstanding stock options and restricted stock awards and are determined using the treasury stock method. Advertising costs Advertising costs are expensed as incurred. Stock-based Compensation Plans The Company measures and recognizes compensation cost relating to stock-based payment transactions based on the grant-date fair value of the equity instruments issued. Stock-based compensation is recognized over the period the employee is required to provide services for the award. The Company uses the Black-Scholes option-pricing model to determine the fair value of stock options granted. Employee Stock Ownership Plan Compensation expense for the Employee Stock Ownership Plan (ESOP) is recorded at an amount equal to the shares allocated by the ESOP multiplied by the average fair market value of the shares during the period. The Company recognizes compensation expense ratably over the year based upon the Company’s estimate of the number of shares expected to be allocated by the ESOP. Unearned compensation applicable to the ESOP is reflected as a reduction of stockholders' equity on the consolidated balance sheet. The difference between the average fair market value and the cost of the shares allocated by the ESOP is recorded as an adjustment to additional paid-in capital. Income taxes Deferred tax assets and liabilities are reflected at currently enacted income tax rates applicable to the period in which the deferred tax assets or liabilities are expected to be realized or settled. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted accordingly through the provision for income taxes. The Company exercises significant judgment in evaluating the amount and timing of recognition of the resulting tax assets and liabilities. These judgments require the Company to make projections of future taxable income. These judgments and estimates, which are inherently subjective, are reviewed periodically as regulatory and business factors change. A valuation allowance related to deferred tax assets is established when, in the judgment of management, it is more likely than not that all or a portion of such deferred tax assets will not be realized. A tax position that meets the more likely than not recognition threshold is initially and subsequently measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position has met the more likely than not recognition threshold considers the facts, circumstances and information available at the reporting date and is subject to management’s judgment. There was no reserve for uncertain tax positions as of December 31, 2015 and 2014 respectively. The Company records interest and penalties as part of income tax expense. Income tax benefits related to stock compensation in excess of grant date fair value less any proceeds on exercise are recognized as an increase to additional paid-in capital upon vesting or exercising and delivery of the stock. Any income tax effects related to stock compensation that are less than grant date fair value less any proceeds on exercise would be recognized as a reduction of additional paid-in capital to the extent of previously recognized income tax benefits and then through income tax expense for the remaining amount. Comprehensive Income Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. Although certain changes in assets and liabilities are reported as a separate component of the equity section of the balance sheet, such items, along with net income, are components of comprehensive income. Reclassification Certain amounts in the 2014 consolidated financial statements have been reclassified to conform to the 2015 presentation.

Recent Accounting Standards Upd

Recent Accounting Standards Updates	12 Months Ended
	Dec. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Standards Updates	RECENT ACCOUNTING STANDARDS UPDATES In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update Update No. 2014-09 issued to address the previous revenue recognition requirements in GAAP that differ from those in International Financial Reporting Standards (IFRS). Accordingly, the FASB and the International Accounting Standards Board (IASB) initiated a joint project to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and IFRS. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. For public entities, the standard is effective for annual and interim periods beginning after December 15, 2017, and calendar year-end public entities will apply it in the quarter that ends March 31, 2018. Early adoption is not permitted. We are currently assessing the potential impact of this amendment on our consolidated financial statements. In September 2015, FASB issued ASU 2015-16, Business Combinations (Topic 805). The amendments in this Update require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. In addition, the amendments require that the acquirer record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. For public business entities, the amendments are effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2016, and interim periods within fiscal years beginning after December 15, 2017. The amendments should be applied prospectively to adjustments to provisional amounts that occur after the effective date of this Update with earlier application permitted for financial statements that have not yet been made available for issuance. 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. The impact of the change in equity investments will depend on maket conditions but if applied in 2015, would have resulted in a loss of $3.7 million (after tax) being recognized in net income versus other comprehensive income. See the Consolidated Statement of Comprehensive Income (Loss). 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. The Update will be effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Management is currently evaluating the impact to the consolidated financial statements of adopting this Update.

Securities

Securities	12 Months Ended
	Dec. 31, 2015
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, follow: December 31, 2015 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 $ 13,126 $ — $ (195 ) $ 12,931 Other asset-backed securities 11,395 — (142 ) 11,253 Total other mortgage- and asset-backed securities 24,521 — (337 ) 24,184 State and political 16,016 354 (55 ) 16,315 Financial services: Banks 18,813 138 (90 ) 18,861 Diversified financial entities 23,124 349 (173 ) 23,300 Insurance and REITs 16,883 1 (282 ) 16,602 Total financial services 58,820 488 (545 ) 58,763 Other corporate: Industrials 55,470 306 (1,244 ) 54,532 Utilities 31,952 7 (1,639 ) 30,320 Total other corporate 87,422 313 (2,883 ) 84,852 Total debt securities 186,779 1,155 (3,820 ) 184,114 Marketable equity securities: Mutual funds: Global equity 5,000 388 — 5,388 Domestic community 3,216 70 (13 ) 3,273 Global asset allocation 42,396 3 (3,484 ) 38,915 Total marketable equity securities 50,612 461 (3,497 ) 47,576 Total securities available for sale $ 237,391 $ 1,616 $ (7,317 ) $ 231,690 Securities Held to Maturity: Debt securities: U.S. Treasury $ 636 $ — $ (2 ) $ 634 Government-sponsored enterprises 28,256 94 (126 ) 28,224 Government-sponsored mortgage-backed and collateralized mortgage obligations 155,232 10 (832 ) 154,410 SBA asset-backed securities 16,017 — (59 ) 15,958 Total securities held to maturity $ 200,141 $ 104 $ (1,019 ) $ 199,226 December 31, 2014 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available for Sale: Debt securities: U.S. Treasury $ 13,037 $ 182 $ — $ 13,219 Government-sponsored enterprises 26,335 131 (29 ) 26,437 Government-sponsored mortgage-backed and collateralized mortgage obligations 160,091 756 (294 ) 160,553 Other mortgage- and asset-backed: Privately issued commercial mortgage-backed securities 22,100 30 (201 ) 21,929 SBA asset-backed securities 27,765 308 (27 ) 28,046 Other asset-backed securities 16,235 — (43 ) 16,192 Total other mortgage- and asset-backed securities 66,100 338 (271 ) 66,167 State and political 15,619 567 (3 ) 16,183 Financial services: Banks 12,364 531 (6 ) 12,889 Diversified financial entities 15,796 354 (18 ) 16,132 Insurance and REITs 9,387 138 (9 ) 9,516 Total financial services 37,547 1,023 (33 ) 38,537 Other corporate: Industrials 34,408 681 (54 ) 35,035 Utilities 16,873 265 (120 ) 17,018 Total other corporate 51,281 946 (174 ) 52,053 Total debt securities 370,010 3,943 (804 ) 373,149 Marketable equity securities: Mutual funds: Global equity 5,000 623 — 5,623 Domestic community 3,216 86 (5 ) 3,297 Global asset allocation 32,956 1,498 (76 ) 34,378 Total marketable equity securities 41,172 2,207 (81 ) 43,298 Total securities available for sale $ 411,182 $ 6,150 $ (885 ) $ 416,447 During the third quarter of 2015, approximately $196.3 million of securities available for sale, with net unrealized gains of $666,000 , were reclassified to held-to-maturity designation. Held-to-maturity investments are investments that management has the positive intent and ability to hold to maturity. If a security is reclassified from available-for-sale to held-to-maturity, the fair value at the time of transfer becomes the security's new cost basis. The unrealized holding gain at the transfer date continues to be reported in other comprehensive income and is amortized over the security's remaining life as an adjustment of yield in a manner similar to a premium or discount. At December 31, 2015, there are $571,000 of net holding gains remaining in other comprehensive income. The amortized cost and estimated fair value of debt securities by contractual maturity at December 31, 2015 follow. 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. Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value (In thousands) Within 1 year $ 6,572 $ 6,578 $ 5,667 $ 5,667 After 1 year through 5 years 85,860 85,640 14,202 14,109 After 5 years through 10 years 62,163 60,144 9,023 9,082 After 10 years 7,663 7,568 — — 162,258 159,930 28,892 28,858 Mortgage- and asset-backed securities and collateralized mortgage obligations amortizing monthly 24,521 24,184 171,249 170,368 Total debt securities $ 186,779 $ 184,114 $ 200,141 $ 199,226 For the years ended December 31, 2015 , 2014 and 2013 , proceeds from sales and calls of securities available for sale amounted to $99.5 million , $362.9 million and $314.9 million , respectively. Gross realized gains amounted to $2.0 million , $4.5 million and $8.7 million , respectively, and gross realized losses amounted to $56,000 , $1.7 million and $3.6 million , respectively. At December 31, 2015 and 2014 , U.S. Treasury and government-sponsored enterprise obligations with an amortized cost of $46.2 million and $30.4 million , respectively, and a fair value of $46.0 million and $30.6 million , respectively, were pledged to secure borrowings. See note 7. The Company continually reviews investment 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 debt 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. 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: December 31, 2015 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 $ (84 ) $ 5,166 $ (111 ) $ 7,765 Other asset-backed securities (142 ) 11,253 — — Total other mortgage- and asset-backed securities (226 ) 16,419 (111 ) 7,765 State and political (55 ) 3,324 — — Financial services: Banks (90 ) 14,070 — — Diversified financial entities (173 ) 15,397 — — Insurance and REITs (282 ) 14,487 — — Total financial services (545 ) 43,954 — — Other corporate: Industrials (957 ) 43,848 (287 ) 395 Utilities (1,387 ) 25,353 (252 ) 1,618 Total other corporate (2,344 ) 69,201 (539 ) 2,013 Total debt securities (3,170 ) 132,898 (650 ) 9,778 Marketable equity securities: Mutual funds: Domestic community — — (13 ) 453 Global asset allocation (3,484 ) 36,609 — — Total marketable equity securities (3,484 ) 36,609 (13 ) 453 Total temporarily impaired available-for-sale securities $ (6,654 ) $ 169,507 $ (663 ) $ 10,231 Securities Held to Maturity: Debt securities: U.S. Treasury $ (2 ) $ 634 $ — $ — Government-sponsored enterprises (126 ) 14,084 — — Government-sponsored mortgage-backed and collateralized mortgage obligations (832 ) 144,820 — — SBA asset-backed securities (59 ) 15,958 — — Total temporarily impaired held-to-maturity securities $ (1,019 ) $ 175,496 $ — $ — December 31, 2014 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: Government-sponsored enterprises $ (12 ) $ 5,932 $ (17 ) $ 1,080 Government-sponsored mortgage-backed and collateralized mortgage obligations (190 ) 93,364 (104 ) 8,425 Other mortgage- and asset-backed: Privately issued commercial mortgage- backed securities (69 ) 9,412 (132 ) 8,759 SBA asset-backed securities (27 ) 5,529 — — Other asset-backed securities (43 ) 16,192 — — Total other mortgage- and asset-backed securities (139 ) 31,133 (132 ) 8,759 State and political (3 ) 1,955 — Financial services: Banks (6 ) 2,907 — — Diversified financial entities (18 ) 7,676 — — Insurance and REITs (9 ) 4,177 — — Total financial services (33 ) 14,760 — — Other corporate: Industrials (54 ) 9,575 — — Utilities (120 ) 7,291 — — Total other corporate (174 ) 16,866 — — Total debt securities (551 ) 164,010 (253 ) 18,264 Marketable equity securities: Mutual funds: Domestic community — — (5 ) 462 Global asset allocation (76 ) 7,057 — — Total marketable equity securities (76 ) 7,057 (5 ) 462 Total temporarily impaired securities $ (627 ) $ 171,067 $ (258 ) $ 18,726 Management evaluates securities for other-than-temporary impairment at least on a quarterly basis, and more frequently when economic or market concerns warrant such evaluation. At December 31, 2015 , several debt securities have unrealized losses with aggregate depreciation of 2% 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 market value is attributable to changes in interest rates and not to credit quality, and because the Company does not intend to sell the securities and it is more likely than not that the Company will not be required to sell the securities before recovery of their amortized cost bases, which may be maturity, the Company does not consider these securities to be other-than-temporarily impaired at December 31, 2015 . At December 31, 2015 , several mutual funds have aggregate unrealized losses of $3.5 million ; 9% of the Company’s cost basis. No issues have been identified that cause management to believe the declines in market value are other than temporary and the Company has the ability and intent to hold these investments until a recovery of fair value.

Loans and The Allowance for Loa

Loans and The Allowance for Loan Loss	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Loans and The Allowance for Loan Loss	LOANS AND THE ALLOWANCE FOR LOAN LOSS A summary of the balances of loans follows: December 31, 2015 2014 (In thousands) Real estate: 1-4 family residential $ 599,938 $ 460,273 Home equity 77,399 61,750 Commercial real estate 561,203 387,807 Construction 79,773 53,606 1,318,313 963,436 Commercial business 182,677 151,823 Consumer 38,186 31,778 Total loans 1,539,176 1,147,037 Allowance for loan losses (17,102 ) (12,973 ) Discount and fair value adjustments on purchased loans (1,959 ) (2,970 ) Deferred loan costs and fees, net 3,160 1,820 Loans, net $ 1,523,275 $ 1,132,914 The Company has sold residential mortgage loans in the secondary mortgage market, some of which are sold with limited recourse. The Company has retained the servicing responsibility and receives fees for the services provided. The unpaid principal balances of mortgage loans serviced for others were $39.8 million , $56.3 million and $47.6 million at December 31, 2015 , 2014 and 2013 , respectively. The maximum contingent liability associated with loans sold with recourse is $1.2 million at December 31, 2015 . Neither mortgage loans serviced for others nor the contingent liability associated with sold loans is recorded on the consolidated balance sheets. In 2015 and 2014 , the Company transferred a portion of its originated commercial real estate loans to participating lenders. The amounts transferred have been accounted for as sales and are therefore not included on the consolidated balance sheets. The Company and participating lenders share ratably in cash flows and any gains or losses that may result from a borrower’s lack of compliance with contractual terms of the loan. The Company continues to service the loans on behalf of the participating lenders and, as such, collects cash payments from the borrowers, remits payments (net of servicing fees) to participating lenders and disburses required escrow funds to relevant parties. At December 31, 2015 and 2014 , the Company was servicing loans for participants aggregating $30.6 million and $21.9 million , respectively. Activity in the allowance for loan losses for the year ended December 31, 2015 , 2014 and 2013 and allocation of the allowance to loan segments as of December 31, 2015 and 2014 follows: 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Unallocated Total (In thousands) 2015 Beginning balance $ 3,222 $ 340 $ 3,551 $ 1,056 $ 3,410 $ 736 $ 658 $ 12,973 Provision (credit) for loan losses 612 296 3,596 308 (571 ) 79 (230 ) 4,090 Loans charged-off — — — — — (43 ) — (43 ) Recoveries 82 — — — — — — 82 Ending Balance $ 3,916 $ 636 $ 7,147 $ 1,364 $ 2,839 $ 772 $ 428 $ 17,102 2014 Beginning balance $ 2,835 $ 247 $ 2,608 $ 303 $ 2,416 $ 574 $ 688 $ 9,671 Provision (credit) for loan losses 405 93 943 753 994 223 (30 ) 3,381 Loans charged-off (18 ) — — — — (61 ) — (79 ) Recoveries — — — — — — — — Ending Balance $ 3,222 $ 340 $ 3,551 $ 1,056 $ 3,410 $ 736 $ 658 $ 12,973 2013 Beginning balance $ 2,725 $ 316 $ 1,343 $ 106 $ 565 $ 313 $ 182 $ 5,550 Provision (credit) for loan losses 39 (69 ) 1,265 197 1,851 305 506 4,094 Loans charged-off (165 ) — — — — (44 ) — (209 ) Recoveries 236 — — — — — — 236 Ending Balance $ 2,835 $ 247 $ 2,608 $ 303 $ 2,416 $ 574 $ 688 $ 9,671 Additional information pertaining to the allowance for loan losses at December 31, 2015 and December 31, 2014 is as follows: 1-4 Family Home Commercial Construction Commercial Consumer Unallocated Total (In thousands) December 31, 2015 Allowance related to impaired loans $ — $ — $ 384 $ — $ 10 $ 10 $ — $ 404 Allowance related to non-impaired loans 3,916 636 6,763 1,364 2,829 762 428 16,698 Total allowance for loan losses $ 3,916 $ 636 $ 7,147 $ 1,364 $ 2,839 $ 772 $ 428 $ 17,102 Impaired loans $ 6,114 $ 270 $ 4,631 $ — $ 10 $ 145 $ — $ 11,170 Non-impaired loans 593,824 77,129 556,572 79,773 182,667 38,041 — 1,528,006 Total loans $ 599,938 $ 77,399 $ 561,203 $ 79,773 $ 182,677 $ 38,186 $ — $ 1,539,176 December 31, 2014 Allowance related to impaired loans $ — $ — $ — $ — $ — $ — $ — $ — Allowance related to non-impaired loans 3,222 340 3,551 1,056 3,410 736 658 12,973 Total allowance for loan losses $ 3,222 $ 340 $ 3,551 $ 1,056 $ 3,410 $ 736 $ 658 $ 12,973 Impaired loans $ 4,419 $ 578 $ — $ — $ — $ 27 $ — $ 5,024 Non-impaired loans 455,854 61,172 387,807 53,606 151,823 31,751 — 1,142,013 Total loans $ 460,273 $ 61,750 $ 387,807 $ 53,606 $ 151,823 $ 31,778 $ — $ 1,147,037 The following is a summary of past due and non-accrual loans, by loan class, at December 31, 2015 and December 31, 2014 : 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) December 31, 2015 Real estate: 1-4 family residential $ 2,287 $ — $ 990 $ 3,277 $ 5,688 Home equity 1,031 19 176 1,226 270 Commercial real estate — 1,249 — 1,249 4,631 Commercial business 23 — — 23 10 Consumer 3 80 120 203 145 Total $ 3,344 $ 1,348 $ 1,286 $ 5,978 $ 10,744 December 31, 2014 Real estate: 1-4 family residential $ 3,137 $ 522 $ 1,370 $ 5,029 $ 3,876 Home equity 680 — 475 1,155 578 Consumer 217 — 5 222 27 Total $ 4,034 $ 522 $ 1,850 $ 6,406 $ 4,481 There were no loans past due 90 days or more and still accruing at December 31, 2015 and 2014 . The commercial loans in the 60-89 day bucket above are also included in the loans on non-accrual total at December 31, 2015 The following is a summary of information pertaining to impaired loans by loan segment at the dates indicated: Recorded Investment Unpaid Principal Balance Related Allowance December 31, 2015 (In thousands) Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 6,114 $ 6,824 $ — Home equity 270 425 — Consumer 35 39 — Total 6,419 7,288 — Impaired loans with a valuation allowance: Commercial real estate 4,631 4,631 384 Commercial business 10 11 10 Consumer 110 110 10 Total 4,751 4,752 404 Total impaired loans $ 11,170 $ 12,040 $ 404 December 31, 2014 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,419 $ 5,211 $ — Home Equity 578 804 — Consumer 27 25 — Total impaired loans $ 5,024 $ 6,040 $ — The following tables set forth information regarding average balances and interest income recognized (all on a cash basis) on impaired loans, by segment, for the years ended December 31, 2015 , 2014 and 2013 : Average Recorded Investment Interest Income Recognized 2015 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,869 $ 270 Home equity 575 14 Consumer 34 4 Impaired loans with a valuation allowance: Commercial real estate 926 161 Commercial business 2 1 Consumer 44 2 Total $ 6,450 $ 452 2014 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,076 $ 213 Home equity 476 17 Consumer 34 2 Total $ 4,586 $ 232 2013 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 2,586 $ 61 Home equity 32 — Total $ 2,618 $ 61 None of the loans acquired in the acquisition of Nantucket Bank were deemed to be Purchased Credit Impaired ("PCI"). No additional funds are committed to be advanced in connection with impaired loans. Troubled debt restructurings entered into during the years ended December 31, 2015 and 2014: Number of contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment 2015 (Dollars in thousands) Real estate: 1-4 family residential 4 $ 728 $ 750 2014: Real estate: 1-4 family residential 1 $ 181 $ 193 In both 2015 and 2014, residential real estate loans were modified to capitalize past due interest. Management performs a discounted cash flow calculation to determine the amount of impairment reserve required on each of the troubled debt restructurings. Any reserve required is recorded through the provision for loan losses. There were two troubled debt restructurings that defaulted during the year ended December 31, 2015, for which default was within one year of the restructure date. There were no troubled debt restructurings that defaulted during the year ended December 31, 2014. 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 assets. 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 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. Management primarily 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 December 31, 2015 and December 31, 2014 : 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Total Loans (In thousands) December 31, 2015 Loans rated 1 - 6 $ 1,950 $ 465 $ 548,360 $ 79,773 $ 181,792 $ 6 $ 812,346 Loans rated 7 4,461 321 7,765 — 874 — 13,421 Loans rated 8 1,592 144 5,078 — — 149 6,963 Loans rated 9 701 — — — 11 — 712 Loans rated 10 — — — — — — — Loans not rated 591,234 76,469 — — — 38,031 705,734 $ 599,938 $ 77,399 $ 561,203 $ 79,773 $ 182,677 $ 38,186 $ 1,539,176 December 31, 2014 Loans rated 1 - 6 $ 3,381 $ 473 $ 387,651 $ 53,606 $ 150,960 $ 5 $ 596,076 Loans rated 7 3,095 852 156 — 863 — 4,966 Loans rated 8 1,331 — — — — 31 1,362 Loans rated 9 709 — — — — — 709 Loans rated 10 — — — — — — — Loans not rated 451,757 60,425 — — — 31,742 543,924 $ 460,273 $ 61,750 $ 387,807 $ 53,606 $ 151,823 $ 31,778 $ 1,147,037

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Premises and equipment	PREMISES AND EQUIPMENT A summary of the cost and accumulated depreciation and amortization of premises and equipment follows: December 31, Estimated Useful Lives 2015 2014 (In thousands) Land $ 4,087 $ 4,087 Buildings 10,322 10,293 5 to 40 years Leasehold improvements 7,727 6,109 5 to 10 years Furniture and fixtures 2,601 2,014 3 to 5 years Technology equipment 5,088 4,266 1 to 3 years Construction in progress 70 75 Property, plant and equipment, gross 29,895 26,844 Less accumulated depreciation and amortization (9,880 ) (8,056 ) Property, plant and equipment, net $ 20,015 $ 18,788 Depreciation and amortization expense for the years ended December 31, 2015 , 2014 and 2013 amounted to $1.8 million , $1.5 million and $1.4 million , respectively.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2015
Banking and Thrift [Abstract]
Deposits	DEPOSITS A summary of deposit balances, by type, is as follows: December 31, 2015 2014 (In thousands) NOW and demand $ 288,143 $ 245,117 Regular savings 287,344 303,834 Money market 368,050 280,139 Brokered money market 41,807 23,166 Total non-certificate accounts 985,344 852,256 Term certificates of $250,000 or more 65,364 56,325 Term certificates less than $250,000 246,614 245,430 Brokered certificates of deposit 136,527 58,705 Total certificate accounts 448,505 360,460 Total deposits $ 1,433,849 $ 1,212,716 At December 31, 2015 , the scheduled maturities of term certificate accounts, including brokered deposits, are as follows: Amount Weighted Average Rate (Dollars in thousands) 2016 239,134 0.62 % 2017 86,464 1.10 2018 40,570 1.37 2019 44,630 1.90 2020 37,707 1.92 $ 448,505 1.01 %

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Borrowings	BORROWINGS Federal Home Loan Bank of Boston advances FHLBB advances with an original maturity of less than one year amounted to $205.0 million and $40.0 million at December 31, 2015 and 2014 , respectively, with a weighted average rate of 0.41% and 0.24% , respectively. The Company also had, at both December 31, 2015 and 2014, a $7.7 million line of credit with the FHLBB with an interest rate that adjusts daily. No advances were outstanding on this line at December 31, 2015 and 2014 . All borrowings from the FHLBB are secured by a blanket security agreement on qualified collateral, principally residential and commercial mortgage loans, U.S. Treasury and by U.S. government-sponsored enterprise securities. See notes 3 and 4. Long-term debt consists of the following FHLBB advances: December 31, 2015 December 31, 2014 Amount Weighted Average Rate Amount Weighted Average Rate (Dollars in thousands) Fixed-rate advances maturing: 2016 $ 10,000 2.29 % $ 10,000 2.29 % 2017 15,000 1.99 15,000 1.99 2018 20,000 2.23 10,000 3.16 2020 10,000 1.65 — — $ 55,000 2.07 % $ 35,000 2.41 % Other lines-of-credit At December 31, 2015 and 2014 , the Company had $39.0 million and $32 million respectively, in available unsecured federal funds lines with correspondent banks, which could be drawn upon, as needed. There were no amounts outstanding at December 31, 2015 or 2014 .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Allocation of federal and state income taxes between current and deferred portions is as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Current tax provision: Federal $ 2,933 $ 2,695 $ 960 State 206 240 172 3,139 2,935 1,132 Deferred tax provision (benefit): Federal 7 (3,183 ) (1,609 ) State (148 ) (1,014 ) (502 ) Federal and State (141 ) (4,197 ) (2,111 ) Change in valuation reserve (161 ) 640 695 Deferred income tax benefit (302 ) (3,557 ) (1,416 ) Provision (benefit) for income taxes $ 2,837 $ (622 ) $ (284 ) The reasons for the differences between the statutory federal income tax provision and the actual tax provision (benefit) are summarized as follows: Years Ended December 31, 2015 2014 2013 (Dollars in thousands) Statutory federal tax provision (benefit) at 34% $ 3,429 $ (274 ) $ 809 Increase (decrease) resulting from: State taxes, net of federal tax benefit 39 (511 ) (218 ) Dividends received deduction (211 ) (201 ) (134 ) Tax-exempt bank-owned life insurance (351 ) (404 ) (984 ) Tax-exempt interest (222 ) (277 ) (224 ) Change in valuation reserve (161 ) 640 695 Nondeductible IPO costs — 202 — Other, net 314 203 (228 ) Tax provision (benefit) $ 2,837 $ (622 ) $ (284 ) Effective tax rates 28.2 % 77.3 % (11.9 )% The components of the net deferred tax asset (liability) are as follows: December 31, 2015 2014 (In thousands) Deferred tax assets: Federal $ 12,091 $ 8,453 State 3,188 2,543 Deferred tax assets, gross 15,279 10,996 Valuation reserve (1,966 ) (2,012 ) Deferred tax assets, net 13,313 8,984 Deferred tax liabilities: Federal (2,138 ) (2,429 ) State (510 ) (322 ) Deferred tax liabilities, gross (2,648 ) (2,751 ) Net deferred tax asset $ 10,665 $ 6,233 The tax effects of each item that give rise to deferred tax assets (liabilities) are as follows: December 31, 2015 2014 (In thousands) Deferred tax assets: Depreciation and amortization $ 929 $ 603 Employee benefit plans and share-based compensation plans 901 682 Allowance for loan losses 6,831 5,181 Contribution carryover 2,675 3,281 Net unrealized loss on securities held as, or transferred from, available for sale 1,748 — Net unrealized losses on defined benefit pension plan 1,052 543 Other 159 71 Valuation reserve (1,966 ) (2,012 ) Deferred tax liabilities: Deferred loan origination costs (1,664 ) (243 ) Net unrealized gain on securities available for sale — (1,873 ) Net deferred tax asset $ 10,665 $ 6,233 A summary of the change in the net deferred tax asset (liability) is as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Balance at beginning of year $ 6,233 $ 2,831 $ (3,165 ) Deferred tax benefit 302 3,557 1,416 Tax effect of changes in accumulated other comprehensive income 4,130 (155 ) 4,580 Balance at end of year $ 10,665 $ 6,233 $ 2,831 At December 31, 2015 and 2014, management maintained a valuation reserve in the amount of $2.0 million , related to state deferred tax assets, for which it was more likely than not, that a tax benefit will not be realized due to lack of positive evidence to support future state profitability. In addition, a portion of the valuation allowance relates to federal charitable contribution carryover for which it is more likely than not be utilized in the allowed five years carryforward period. A summary of the change in valuation allowance is as follows: For the Year Ended December 31, 2015 Federal State Total (In thousands) Balance at beginning of year $ (544 ) $ (1,468 ) $ (2,012 ) Change through the income statement 344 (183 ) 161 Change through other comprehensive income — (115 ) (115 ) Balance at end of year $ (200 ) $ (1,766 ) $ (1,966 ) At December 31, 2015, the Company allocated tax expense between the components of the income statement as required by the intraperiod allocation rules. The federal income tax reserve for loan losses at the Company’s base year amounted to $1.3 million. If any portion of the reserve is used for purposes other than to absorb loan losses, approximately 150% of the amount actually used (limited to the amount of the reserve) would be subject to taxation in the year in which used. As the Company intends to use the reserve to only absorb loan losses, a deferred income tax liability of $503,000 has not been provided. The Company’s income tax returns are subject to review and examination by federal and state taxing authorities. The Company is currently open to audit under the applicable statutes of limitations by the Internal Revenue Service and state taxing authorities for the years ended December 31, 2012 through 2015 . Management periodically evaluates the sustainability of tax positions taken. Whenever management estimates the probability of sustaining a tax position is at least more likely than not, the tax position is deemed warranted and is recognized at the largest amount of benefit that is greater than 50% likely of being realized upon settlement. Interest and penalties related to uncertain tax positions are recognized as income tax expense. No interest or penalties were recorded for the years ended December 31, 2015 , 2014 and 2013 .

Equity

Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Equity	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. Effective January 1, 2015, federal banking regulations changed with regard to minimum capital requirements for community banking institutions. The regulations include a new minimum ratio of common equity Tier 1 capital to risk-weighted assets of 4.5% , raise the minimum ratio of Tier 1 capital to risk-weighted assets from 4% to 6% and include a minimum leverage ratio of 4% for all banking organizations. 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 will be phased in over three years , beginning on January 1, 2016. Also, certain new deductions from and adjustments to regulatory capital will be phased in over several years. Management believes that the Company’s capital levels will remain characterized as “well capitalized” throughout the phase in periods. As of December 31, 2015 , 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 December 31, 2015 and 2014 , 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 December 31, 2015 and 2014 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.: December 31, 2015 Total capital (to risk weighted assets) $ 407,444 24.8 % $ 131,231 8.0 % 164,039 10.0 % Tier 1 capital (to risk weighted assets) 390,342 23.8 98,423 6.0 131,231 8.0 Common equity Tier 1(to risk weighted assets) 390,342 23.8 73,818 4.5 106,625 6.5 Tier 1 capital (to average assets) 390,342 19.6 79,658 4.0 99,573 5.0 December 31, 2014 Total capital (to risk weighted assets) 409,545 32.6 100,513 8.0 N/A N/A Tier 1 capital (to risk weighted assets) 395,615 31.5 50,257 4.0 N/A N/A Common equity Tier 1(to risk weighted assets) N/A N/A N/A N/A N/A N/A Tier 1 capital (to average assets) 395,615 23.3 67,820 4.0 N/A N/A Blue Hills Bank: December 31, 2015 Total capital (to risk weighted assets) 296,309 18.1 130,832 8.0 163,540 10.0 Tier 1 capital (to risk weighted assets) 279,207 17.1 98,124 6.0 130,832 8.0 Common equity Tier 1(to risk weighted assets) 279,207 17.1 73,593 4.5 106,301 6.5 Tier 1 capital (to average assets) 279,207 14.0 79,867 4.0 99,608 5.0 December 31, 2014 Total capital (to risk weighted assets) 283,443 22.7 99,973 8.0 124,966 10.0 Tier 1 capital (to risk weighted assets) 269,513 21.6 49,987 4.0 74,980 6.0 Common equity Tier 1(to risk weighted assets) N/A N/A N/A N/A N/A N/A Tier 1 capital (to average assets) 269,513 15.9 67,707 4.0 84,634 5.0 Preferred stock On September 22, 2011, Hyde Park Bancorp, Inc. issued and sold 18,724 shares of senior non-cumulative perpetual preferred stock, Series A (“Series A Preferred”), with a liquidation value of $1,000 per share. Hyde Park Bancorp, Inc. sold the Series A Preferred to the U.S. Treasury as part of the Small Business Lending Fund Program (“SBLF”) for an aggregate purchase price of $18.7 million . On July 11, 2014, the Company redeemed the $18.7 million of Series A Preferred Stock issued to the U.S. Treasury under the Small Business Lending Fund (“SBLF”) preferred stock program. The redemption was completed with a payment to the U.S. Treasury of $18.7 million plus accrued dividends. As part of the conversion, the Board of Directors of the Company authorized 50,000,000 shares, zero par value of Preferred Stock ("Preferred Stock"). As of December 31, 2015 there were no shares issued or outstanding. Restrictions on dividends, loans and advances Federal and state banking regulations place certain restrictions on dividends paid and loans or advances made by the Bank to the Company. The total amount of dividends which may be paid in any calendar year cannot exceed the Bank’s net income for the current year, plus the Bank’s net income retained for the two previous years, without regulatory approval. Loans or advances are limited to 10 percent of the Bank’s capital stock and surplus on a secured basis. The payment of dividends by the Company is subject to Maryland law. The Company can pay dividends on its common stock if, after giving effect to such distribution, (i) it would be able to pay its indebtedness as the indebtedness comes due in the usual course of business and (ii) its total assets exceed the sum of its liabilities and the amount needed, if Blue Hills Bancorp were to be dissolved at the time of the distribution, to satisfy the preferential rights upon dissolution of any holders of capital stock who have a preference in the event of dissolution; provided, however, that even if the Company's assets are less than the amount necessary to satisfy the requirement set forth in (ii) above, the Company may make a distribution from: (A) The Company's net earnings for the fiscal year in which the distribution is made; (B) The Company's net earnings for the preceding fiscal year; or (C) the sum of the Company's net earnings for the preceding eight fiscal quarters. The holders of common stock of the Company will be entitled to receive and share equally in dividends as may be declared by our board of directors out of funds legally available. If the Company issues shares of preferred stock, the holders thereof may have a priority over the holders of the common stock with respect to dividends. At December 31, 2015, the Bank's retained earnings available for the payment of dividends was $157.9 million . Accordingly, $130.8 million of the Company's equity in the net assets of the Bank was restricted at December 31, 2015. Funds available for loans or advances by the Bank to the Company amounted to $29.1 million . In addition, dividends paid by the Bank to the Company would be prohibited if the effect thereof would cause the Bank’s capital to be reduced below applicable capital requirements.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Pension plan The Company has historically provided basic and supplemental pension benefits for eligible employees through the Savings Banks Employees Retirement Association’s (“SBERA”) Pension Plan (the “Plan”). Each employee reaching the age of 21 and having completed at least 1000 hours of service in any one twelve -month period, beginning with such employee’s date of employment were automatically enrolled in the Plan. The Company accounts for its defined benefit pension plan using an actuarial model that allocates pension costs over the service period of employees in the plan. The Company accounts for the over-funded or under-funded status of its defined benefit plan as an asset or liability on its consolidated balance sheets and recognizes changes in the funded status in the year in which the changes occur as other comprehensive income or loss. The Company amended its defined benefit pension plan in 2013 by freezing the plan to new participants and subsequently amended the plan and froze it for all participants effective October 31, 2014. Accumulated benefits for participants earned through the end of October 2014 will remain secured by the Plan assets. Years Ended December 31, 2015 2014 2013 (In thousands) Change in plan assets: Fair value of plan assets at beginning of year $ 9,443 $ 9,535 $ 9,331 Actual return (loss) on plan assets (304 ) 391 1,513 Benefits paid (325 ) (483 ) (1,309 ) Fair value of plan assets at end of year 8,814 9,443 9,535 Change in benefit obligation: Benefit obligation at beginning of year 10,135 9,287 10,818 Service cost — 484 708 Interest cost 401 407 423 Actuarial loss (gain) 561 2,230 (1,353 ) Benefits paid (325 ) (483 ) (1,309 ) Curtailment gain — (1,790 ) — Benefit obligation at end of year 10,772 10,135 9,287 Funded status and prepaid expense (accrued liability) at end of year $ (1,958 ) $ (692 ) $ 248 Accumulated benefit obligation at end of year $ 10,772 $ 10,135 $ 7,507 At December 31, 2015 and 2014, the discount rate used to determine the benefit obligation was as follows: December 31, 2015 2014 Discount rate 4.01 % 4.00 % Rate of compensation increase n/a n/a The components of net periodic pension cost (benefit) are as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Service cost $ — $ 484 $ 708 Interest cost 401 407 423 Expected return on plan assets (745 ) (735 ) (728 ) Amortization of net actuarial loss (gain) 110 (70 ) 104 Settlement gain — — (107 ) Curtailment gain — (1,304 ) — Net periodic pension cost (benefit) $ (234 ) $ (1,218 ) $ 400 The assumptions used to determine net periodic pension cost are as follows: Years Ended December 31, 2015 2014 2013 Discount rate 4.00 % 4.25 % 4.00 % Expected long-term rate of return on plan assets 8.00 % 8.00 % 8.00 % Rate of compensation increase n/a n/a 3.00 % The Company has selected its assumption with respect to the expected long-term rate of return based on prevailing yields on high quality fixed income investments increased by a premium for equity return expectations. SBERA offers a common and collective trust as the underlying investment structure for pension plans participating in SBERA. The target allocation mix for the common and collective trust portfolio calls for an equity-based investment range from 40% to 64% of total portfolio assets. The remainder of the portfolio is allocated to fixed income from 15% to 25% and other investments including global asset allocation and hedge funds from 20% to 36% . The Trustees of SBERA, through the Investment Committee, select investment managers for the common and collective trust portfolio. A professional investment advisory firm is retained by the Investment Committee to provide allocation analysis, performance measurement and to assist with manager searches. The overall investment objective is to diversify equity investments across a spectrum of investment types and styles. The fair value of major categories of the Company’s pension plan assets are summarized below: Level 1 Level 2 Level 3 Total Fair Value (In thousands) December 31, 2015 Collective funds $ 1,126 $ 4,266 $ — $ 5,392 Equity securities 1,566 — — 1,566 Mutual funds 1,046 — — 1,046 Hedge funds — — 660 660 Short-term investments 150 — — 150 $ 3,888 $ 4,266 $ 660 $ 8,814 December 31, 2014 Collective funds $ 770 $ 4,276 $ — $ 5,046 Equity securities 2,178 — — 2,178 Mutual funds 1,330 134 — 1,464 Hedge funds — — 659 659 Short-term investments 96 — — 96 $ 4,374 $ 4,410 $ 659 $ 9,443 The fair value hierarchy above was received from SBERA, the plan administrator. The Plan assets measured at fair value in Level 1 are based on quoted market prices in an active exchange market. Plan assets measured at fair value in Level 2 are 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. Plan assets measured at fair value in Level 3 are based on unobservable inputs, which include the SBERA’s assumptions and the best information available under the circumstance. For the years ended December 31, 2015 and 2014 , there were no significant changes in Plan assets that are measured in Level 3. Estimated future benefit payments, assuming employees retire at age 65 and take normal distribution payments, are as follows: Amount Year Ending December 31, (In thousands) 2016 $ 495 2017 679 2018 934 2019 543 2020 655 2021-2025 3,239 The Company contributed $ 470,000 to the Plan in February 2016. No further contributions are anticipated during 2016. 401(k) Plan The Company has a 401(k) Plan whereby each employee having completed at least three months of service beginning with their date of employment, automatically becomes a participant in the 401(k) Plan. Employees may contribute a portion of their compensation subject to certain limits based on Federal tax laws. Effective December 15, 2013, the Company enhanced its 401(k) Plan to include a 3% guaranteed non-elective contribution and a 2% elective contribution based on the financial performance of the Company. Effective January 1, 2015, the Company amended the 401(k) Plan to incorporate an overall 4% contribution that matches 100% of an employee’s first 3% of deferral and 50% of the next 2% deferral. In 2014, the Bank provided a 3% contribution. For the years ended December 31, 2015 and 2014 expenses related to the plan were $610,000 and $465,000 . Prior to 2014, the Company did not contribute to the 401(k) plan. Supplemental Executive Retirement Plans The Company entered into agreements with various executives and Board members which provided for a fixed dollar amount to be contributed each year to the participant’s supplemental executive retirement account. All benefits under these agreements became fully vested after five years of service, however during 2013 these agreements were terminated and all vesting was accelerated. No further awards have or will be granted under these agreements. Expenses associated with these agreements amounted $873,000 for the year ended December 31, 2013 . The Supplemental Executive Retirement Plan was terminated in a manner that complies with Section 409A of the Internal Revenue Code, whereby benefits could not be distributed for 12 months following the plan’s termination but were required to be distributed in full no later than 24 months following the plan’s termination. To allow participants the opportunity to use their account balances within the plan to purchase Blue Hills Bancorp common stock in the stock offering prior to the date the account is distributed, the plan was amended prior to its termination. All participants elected to invest in employer stock and all participant balances were distributed in Blue Hills Bancorp common stock in December 2015. In connection with the distributions, 27,956 shares were redeemed by the Company for tax withholding. Short-term Incentive Compensation All employees meeting specified service requirements are eligible to participate in the discretionary Short-term Incentive Compensation Plan. The purpose of the plan is to motivate and reward employees for achieving strategic objectives through a goals program. The Company recorded expenses of $2.3 million , $3.0 million , and $1.6 million for achievement of the 2015 , 2014 and 2013 goals, respectively. 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. The Company contributed funds to the Funding Corporation to enable it to grant a loan to the ESOP for the purchase of 2,277,345 shares of the Company’s common stock at a price of $10.00 per share. The loan obtained by the ESOP from the Funding Corporation to purchase Company common stock is payable annually over 30 years at a rate per annum equal to the Prime Rate ( 3.25% at December 31, 2015 ). Loan payments are principally funded by cash contributions from the Company. The loan is secured by the shares purchased, which are held in a suspense account for allocation among participants as the loan is repaid. The balance of the ESOP loan at December 31, 2015 was $21.5 million . 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: December 31, 2015 December 31, 2014 Allocated 75,912 — Committed to be allocated 75,912 75,912 Unallocated 2,124,846 2,201,433 2,276,670 2,277,345 The fair value of unallocated shares was $32.5 million and $29.9 million at December 31, 2015 and 2014, respectively. Total compensation expense recognized in connection with the ESOP for the years ended December 31, 2015 and 2014 amounted to $1.1 million and $993,000 , respectively.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK 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 . 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 . 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. Under the Equity Plan, the option exercise price is based upon the closing value of the stock on the date of grant. Stock option awards granted to date under the Equity Plan expire in 2025. 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 in 2015 : Date of grant October 7, 2015 Options granted 2,434,000 Vesting period (years) 5 Expiration date October 7, 2025 Expected volatility 28.85 % Expected life (years) 6.5 Expected dividend yield 0.54 % Risk free interest rate 1.55 % Fair value per option $ 4.23 A summary of the status of the Company's stock option grants for the year ended December 31, 2015 , is presented in the table below: Options Stock Option Awards Weighted Average Exercise Price Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value Balance at January 1, 2015 — $ — — $ — Granted 2,434,000 14.07 9.78 3,018,160 Balance at December 31, 2015 2,434,000 $ 14.07 9.78 $ 3,018,160 Outstanding and expected to vest at December 31, 2015 2,434,000 $ 14.07 9.78 $ 3,018,160 Exercisable at December 31, 2015 — $ — — $ — Unrecognized compensation cost $9,822,000 Weighted average remaining recognition period (years) 4.77 For the year ended December 31, 2015 , stock-based compensation expense applicable to the stock options was $473,000 and the recognized tax benefit related to this expense was $112,000 . There was no stock-based compensation expense for the years ended December 31, 2014 and 2013 . 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 in 2015 , 40,000 are performance based. The following table presents the activity in non-vested stock awards under the Equity Plan for the year ended December 31, 2015 : Outstanding Restricted Stock Awards Weighted Average Grant Price Non-vested stock awards at January 1, 2015 — $ — Granted 983,175 14.07 Non-vested stock awards at December 31, 2015 983,175 $ 14.07 Unrecognized compensation cost inclusive of directors' fees $13,182,000 Weighted average remaining recognition period (years) 4.77 Total expense for the restricted stock awards was $651,000 for the year ended December 31, 2015 , and the recognized tax benefits related to this expense was $228,000 . There was no expense related to restricted stock awards for the years ended December 31, 2014 and 2013 .

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Earnings per share consisted of the following components for the year ended December 31, 2015. The Company was not publicly traded for all of 2014 and, as a result, earnings per share is not presented for 2014. (Dollars in thousands, except per share amounts) 2015 Net income applicable to common stock $ 7,227 Average number of common shares outstanding 28,228,425 Less: Average unallocated ESOP shares (2,163,478 ) Average number of common shares outstanding used to calculate basic earnings per common share 26,064,947 Effect of dilutive unvested restricted stock awards 4,642 Average number of common shares outstanding used to calculate diluted earnings per common share 26,069,589 Earnings per common share: Basic $ 0.28 Diluted $ 0.28 Options for 2,434,000 shares were not included in the computation of diluted earnings per share because to do so would have been antidilutive for the year ended December 31, 2015.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES In the normal course of business, there are outstanding commitments and contingencies which are not reflected in the accompanying consolidated financial statements. Loan commitments The Company is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit, which involve elements of credit and interest rate risk in excess of the amount recognized in the accompanying consolidated balance sheets. The contract amount of these instruments reflects the extent of involvement the Company has in these particular classes of financial instruments. The Company’s exposure to credit loss is represented by the contractual amount of the instruments. The Company uses the same credit policies in making commitments as it does for on-balance sheet instruments. Financial instruments whose contract amounts represent credit risk consist of: December 31, 2015 2014 (In thousands) Commitments to originate loans $ 69,554 $ 44,504 Letters of credit 3,571 7,133 Unused lines-of-credit: Commercial 128,748 81,607 Home equity 84,374 37,580 Consumer 16,033 16,057 Undisbursed construction loans 4,844 6,679 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments and unadvanced funds on lines-of-credit generally have fixed expiration dates and may expire without being drawn upon. Therefore, the total commitment amount does not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. These financial instruments are primarily secured by mortgage liens on real estate. Operating lease commitments Pursuant to the terms of noncancelable lease agreements in effect at December 31, 2015 , pertaining to premises, future minimum rent commitments are as follows: Year Ending December 31, Amount (In thousands) 2016 $ 1,801 2017 1,859 2018 1,839 2019 1,595 2020 1,499 Thereafter 8,879 $ 17,472 Rent expense for years ended December 31, 2015 , 2014 and 2013 amounted to $1.6 million , $1.1 million and $966,000 , respectively. Certain leases contain renewal options for up to 30 years. The cost of such options is not included above. Other Commitments Effective January 1, 2014, the Bank entered into an agreement for the naming rights of a Boston waterfront music venue. The agreement spans a ten -year period, with an opt-out option at the end of year seven, where the Bank paid $390,000 during the first year with 5% annual increases in subsequent years. Total expenses related to the agreement was $410,000 and $390,000 for the years ended December 31, 2015 and 2014, respectively. Employment and change in control agreements The Company has entered into an employment agreement with its President and Chief Executive Officer that generally provides for a specified minimum annual compensation and the continuation of certain benefits currently received. Employment may be terminated for cause, as defined, or an aggregate cash severance payment that will be determined based on timing of any other future change in control. The agreement has an initial term of three years, with automatic one -year extensions on the anniversary date of the agreement. The Company has also entered into change in control agreements with certain members of management, including the Company’s Chief Financial Officer, the Company’s Executive Vice President, Commercial Lending, and the Company's Senior Vice President, Chief Risk Officer and others, which provide for the continuation of base salaries for specified periods of time in the event of involuntary termination without cause or termination for good reason in the event of a change in control. In March 2015, the Company revised the change in control agreement with its Chief Financial Officer to be a severance and change in control agreement so that it provided a benefit on an involuntary termination without cause (including resignation for good reason), whether or not the termination occurred in connection with or after a change in control. Contingencies The Company is involved in various litigation and other legal claims that arise in the normal course of business. On May 7, 2014, a complaint was filed with the U.S. Department of Labor’s Occupational Safety and Health Administration (“OSHA”) by a former employee terminated by Blue Hills Bank in October 2013 by which the former employee alleged retaliatory employment practices in violation of the whistleblower provisions of the Consumer Financial Protection Act of 2010, the Dodd-Frank Wall Street Reform and Consumer Protection Act, and the Sarbanes-Oxley Act. The OSHA complaint requested reinstatement of the employee, payment with interest of foregone compensation, including bonuses and employee benefits, medical expenses and attorneys’ fees and litigation expenses in unspecified amounts. On December 30, 2014, the same former employee filed a complaint in U.S. Federal District Court of Massachusetts, based on the same general factual allegations, which alleged violations of the Federal Deposit Insurance Act, the False Claims Act, and the Family and Medical Leave Act. By this complaint, the former employee requested payment with interest of foregone compensation, including bonuses and employee benefits, compensatory and punitive damages, and attorneys’ fees and litigation expenses in unspecified amounts. The Company believes the allegations in these complaints to be completely without merit and intends to vigorously defend both actions and any other action initiated by the former employee. In the opinion of management, these matters will have no material effect on the Company’s consolidated financial statements.

Interest Rate Swap Agreements

Interest Rate Swap Agreements	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest Rate Swap Agreements	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 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 and 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 operations. The Company did not have any fair value hedges or cash flow hedges at December 31, 2015 and December 31, 2014 . The table below presents information about derivative financial instruments not designated as hedging instruments at December 31, 2015 and 2014 . Derivative Gains Derivative Losses Notional Amount Fair Value Notional Amount Fair Value (In thousands) December 31, 2015 Economic hedges: Commercial loan level interest rate swap agreements $ 282,546 $ 7,956 $ 282,546 $ 8,411 Other contracts 8,300 6 12,698 78 Total derivatives $ 290,846 $ 7,962 $ 295,244 $ 8,489 December 31, 2014 Economic hedges: Commercial loan level interest rate swap agreements $ 202,970 $ 5,446 $ 202,970 $ 5,759 Other contracts 8,616 8 8,287 83 Total derivatives $ 211,586 $ 5,454 $ 211,257 $ 5,842 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 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.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASURMENTS 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 financial instruments. 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 instrument. 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 available for sale : 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 obligtaions 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 held for sale : Fair values are based on commitments in effect from investors or prevailing market prices. 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. 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 values 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. Derivative instruments : 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. 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 December 31, 2015 and 2014 , 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) December 31, 2015 Assets Securities available for sale: Debt securities $ — $ 184,114 $ — $ 184,114 Marketable equity securities 47,576 — — 47,576 Derivative assets — 7,962 — 7,962 Total assets $ 47,576 $ 192,076 $ — $ 239,652 Liabilities Derivative liabilities $ — $ 8,489 $ — $ 8,489 December 31, 2014 Assets Securities available for sale: Debt securities $ 13,219 $ 359,930 $ — $ 373,149 Marketable equity securities 43,298 — — 43,298 Derivative assets — 5,454 — 5,454 Total assets $ 56,517 $ 365,384 $ — $ 421,901 Liabilities Derivative liabilities $ — $ 5,842 $ — $ 5,842 Assets measured at fair value on a non-recurring basis The Company may also be required, from time to time, to measure certain other assets at fair value on a nonrecurring 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. At December 31, 2015, there were three impaired loans measured at fair value on a non-recurring basis using level 3 inputs, totaling $4.8 million , with losses on these loans for the year ended December 31, 2015 amounting to $404,000 . At December 31, 2014, there was one impaired loan measured at fair value on a non-recurring basis using level 3 inputs, in the amount of $120,000 , with losses on this loan for the year ended December 31, 2014 amounting to $18,000 . At December 31, 2015 and 2014, there were no liabilities measured at fair value on a non-recurring basis. 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 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) December 31, 2015 Financial assets: Cash and cash equivalents $ 33,298 $ 33,298 $ — $ — $ 33,298 Securities available for sale 231,690 47,576 184,114 — 231,690 Securities held to maturity 200,141 634 198,592 — 199,226 Federal Home Loan Bank stock 13,567 — — 13,567 13,567 Loans and loans held for sale, net 1,536,152 — — 1,538,809 1,538,809 Accrued interest receivable 5,344 — — 5,344 5,344 Financial liabilities: Deposits 1,433,849 — — 1,434,179 1,434,179 Borrowings 260,000 — 260,244 — 260,244 On-balance sheet derivative financial instruments: Interest rate swap agreements: Assets 7,962 — 7,962 — 7,962 Liabilities 8,489 — 8,489 — 8,489 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) December 31, 2014 Financial assets: Cash and cash equivalents $ 60,146 $ 60,146 $ — $ — $ 60,146 Securities available for sale 416,447 56,517 359,930 — 416,447 Federal Home Loan Bank stock 11,702 — — 11,702 11,702 Loans and loans held for sale, net 1,147,505 — — 1,132,024 1,132,024 Accrued interest receivable 4,433 — — 4,433 4,433 Financial liabilities: Deposits 1,212,716 — — 1,214,251 1,214,251 Borrowings 75,000 — 76,074 — 76,074 On-balance sheet derivative financial instruments: Interest rate swap agreements: Assets 5,454 — 5,454 — 5,454 Liabilities 5,842 — 5,842 — 5,842

Other Comprehensive Income

Other Comprehensive Income	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Other Comprehensive Income	OTHER 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 equity on the consolidated balance sheets, such items, along with net income, are components of comprehensive income. The components of accumulated other comprehensive income, included in equity, are as follows: December 31, 2015 2014 (In thousands) Securities available for sale: Net unrealized gain (loss) $ (5,701 ) $ 5,265 Tax effect 1,945 (1,873 ) Net-of-tax amount (3,756 ) 3,392 Securities held to maturity: Net unrealized gain on transferred securities 571 — Tax effect (197 ) — Net-of-tax amount 374 — Defined benefit pension plan: Unrecognized net actuarial loss (2,858 ) (1,358 ) Tax effect 1,052 543 Net-of-tax amount (1,806 ) (815 ) $ (5,188 ) $ 2,577 Changes in accumulated other comprehensive income (loss) by component follows: Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total Year Ended December 31, 2015 Beginning balance $ 3,392 $ — $ (815 ) $ 2,577 Other comprehensive income (loss) before reclassifications (8,332 ) — (1,610 ) (9,942 ) Realized gains reclassified (1,968 ) — — (1,968 ) Amortization of actuarial losses — — 110 110 Unrealized gains on securities reclassified as held to maturity (666 ) 666 — — Amortization of amounts previously recorded upon transfer to held-to-maturity from available-for-sale — (95 ) — (95 ) Tax effects 3,818 (197 ) 509 4,130 Net current-period other comprehensive income (loss) (7,148 ) 374 (991 ) (7,765 ) Ending balance $ (3,756 ) $ 374 $ (1,806 ) $ (5,188 ) Year ended December 31, 2014 Beginning balance $ 1,983 $ — $ 482 $ 2,465 Other comprehensive income (loss) before reclassifications 4,942 — (2,090 ) 2,852 Realized gains reclassified (2,515 ) — — (2,515 ) Amortization of actuarial gains — — (70 ) (70 ) Tax effects (1,018 ) — 863 (155 ) Net current-period other comprehensive income (loss) 1,409 — (1,297 ) 112 Ending balance $ 3,392 $ — $ (815 ) $ 2,577 Year Ended December 31, 2013 Beginning balance $ 10,805 $ — $ (802 ) $ 10,003 Other comprehensive income (loss) before reclassifications (9,256 ) — 2,033 (7,223 ) Realized gains reclassified (4,999 ) — — (4,999 ) Amortization of actuarial losses — — 104 104 Tax effects 5,433 — (853 ) 4,580 Net current-period other comprehensive income (loss) (8,822 ) — 1,284 (7,538 ) Ending balance $ 1,983 $ — $ 482 $ 2,465 Actuarial gains of $271,000 , included in accumulated other comprehensive income at December 31, 2015, are expected to be recognized as a component of net periodic pension cost, included in salaries and employee benefits expense, during the year ending December 31, 2016.

Condensed Financial Statements

Condensed Financial Statements of Parent Company	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Financial Statements of Parent Company	CONDENSED FINANCIAL STATEMENTS OF PARENT COMPANY Financial information pertaining only to Blue Hills Bancorp, Inc. is as follows: December 31, BALANCE SHEETS 2015 2014 (In thousands) Assets Cash balances at Blue Hills Bank $ 100,965 $ 121,632 Total cash and cash equivalents 100,965 121,632 Investment in subsidiaries 311,357 308,606 Other assets 7,993 3,561 Total assets $ 420,315 $ 433,799 Liabilities and Stockholders' Equity Liability to ESOP 21,459 21,925 Accrued expenses 27 $ 268 Stockholders' equity 398,829 411,606 Total liabilities and stockholders' equity $ 420,315 $ 433,799 Years Ended December 31, 2015 2014 2013 STATEMENTS OF OPERATIONS (In thousands) Total income $ 713 $ 331 $ — Operating expenses 1,860 9,432 — Loss before income taxes and equity in undistributed net income of subsidiaries (1,147 ) (9,101 ) — Applicable income tax benefit (1,112 ) (3,277 ) — Loss before equity in income of subsidiaries (35 ) (5,824 ) — Equity in undistributed net income of subsidiaries 7,975 5,972 2,663 Net income (loss) $ 7,940 $ 148 $ 2,663 Years Ended December 31, 2015 2014 2013 STATEMENTS OF CASH FLOWS (In thousands) Cash flows from operating activities: Net income (loss) $ 7,940 $ 148 2,663 Adjustments to reconcile net income (loss) to net cash provided by used for operating activities: Equity in undistributed net income of subsidiaries (7,975 ) (5,972 ) (2,663 ) Issuance of common stock to Charitable Foundation — 6,943 — Net change in other assets (2,221 ) (2,062 ) (44 ) Net change in other liabilities (241 ) 267 — Net cash used for operating activities (2,497 ) (676 ) (44 ) Cash flows from investing activities: Investment in Blue Hills Bank (3,929 ) (161,820 ) — Net cash used for investing activities (3,929 ) (161,820 ) — Cash flows from financing activities: Proceeds from the issuance of common stock — 274,143 — Redemption of SBLF preferred stock — (18,724 ) — Repurchase of common stock (13,121 ) — — Common and Preferred Stock dividends paid (1,120 ) (439 ) (529 ) Net cash provided by (used for) financing activities (14,241 ) 254,980 (529 ) Net change in cash and cash equivalents (20,667 ) 92,484 (573 ) Cash and cash equivalents at beginning of year 121,632 29,148 29,721 Cash and cash equivalents at end of year $ 100,965 $ 121,632 $ 29,148

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) First Quarter Second Quarter Third Quarter Fourth Quarter 2015 2014 2015 2014 2015 2014 2015 2014 (In thousands, except share data) Interest and dividend income $ 12,682 $ 10,169 $ 13,130 $ 11,551 $ 15,418 $ 13,070 $ 17,071 $ 14,485 Interest expense 2,017 1,655 2,015 1,674 2,213 1,651 2,499 1,918 Net interest and dividend income 10,665 8,514 11,115 9,877 13,205 11,419 14,572 12,567 Provision for loan losses 279 714 544 959 1,318 1,438 1,949 270 Other noninterest income 866 1,088 2,210 1,119 1,456 3,025 2,179 1,860 Realized securities gains and impairment losses, net 1,318 541 267 1,191 238 349 145 434 Total noninterest income 2,184 1,629 2,477 2,310 1,694 3,374 2,324 2,294 Total noninterest expense 10,626 10,256 10,660 10,662 10,848 17,748 11,948 10,742 Provision (benefit) for income taxes 638 (428 ) 689 137 923 (1,435 ) 587 1,104 Net income (loss) $ 1,306 $ (399 ) $ 1,699 $ 429 $ 1,810 $ (2,958 ) $ 2,412 $ 2,745 Basic earnings per share $ 0.05 n/a $ 0.06 n/a $ 0.07 n/a $ 0.09 $ 0.10 Diluted earnings per share $ 0.05 n/a $ 0.06 n/a $ 0.07 n/a $ 0.09 $ 0.10 Weighted average common shares (basic) 26,274,738 n/a 26,293,560 n/a 26,183,381 n/a 25,500,755 26,243,957 Weighted average common shares (diluted) 26,274,738 n/a 26,293,560 n/a 26,183,381 n/a 25,554,961 26,243,957

Basis of Presentation and Con28

Basis of Presentation and Consolidation (Policies)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries, Blue Hills Funding Corporation and the Bank, the principal operating entity and its wholly-owned subsidiaries, B.H. Security Corporation and HP Security Corporation, which are Massachusetts security corporations, and 1196 Corporation, which holds a restricted stock. All significant intercompany balances and transactions have been eliminated in consolidation. Prior to the the establishment of the Foundation in 2014, the Company established Blue Hills Bank Charitable Foundation, (the "Charitable Foundation"), a not-for-profit organization, to provide charitable contributions within the Company’s surrounding communities. Neither the Foundation or Charitable Foundation are subsidiaries of the Company.
Use of estimates	Use of estimates In preparing consolidated financial statements in conformity with accounting principles generally accepted in the United States of America, 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 realizability of deferred tax assets.
Cash and cash equivalents	Cash and cash equivalents For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash on hand, balances due from banks, and short-term investments comprised of federal funds sold, money-market mutual funds, and interest-bearing deposits, all of which mature within ninety days. The Company normally maintains balances on deposit with other financial institutions in excess of the federally insured limit.
Restrictions on cash and due from banks	Restrictions on cash and due from banks The Company is required to maintain average balances on hand or with the Federal Reserve Bank (“FRB”).
Fair value hierarchy	Fair value hierarchy The Company groups its assets and liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. Level 1 - Valuation is based on quoted prices in active markets for identical assets or liabilities. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities Level 2 - Valuation is based on observable inputs other than Level 1 prices, such as quoted prices for similar assets and liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets and liabilities. Level 3 - Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include those whose value is determined using unobservable inputs to pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation.
Securities	Securities Debt securities that management has the positive intent and ability to hold to maturity are classified as “held to maturity” and recorded at amortized cost. Securities not classified as held to maturity, including equity securities with readily determinable fair values, are classified as “available for sale” and recorded at fair value, with unrealized gains and losses excluded from earnings and reported in other comprehensive income. Purchase premiums and discounts are recognized in interest income using the interest method over the terms of the securities. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. At least quarterly, and more frequently when warranted by economic or market conditions, management evaluates all securities with a decline in fair value below the amortized cost of the investment to determine whether or not the impairment is deemed to be other-than-temporary (OTTI). OTTI is required to be recognized if: (1) the Company intends to sell the security; (2) it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis; or (3) for debt securities, the present value of expected cash flows is not sufficient to recover the entire amortized cost basis. For all impaired debt securities that the Company intends to sell, or more likely than not will be required to sell, the full amount of the depreciation is recognized as OTTI through earnings. Credit-related OTTI for all other impaired debt securities is recognized through earnings. Non-credit related OTTI for such debt securities is recognized in other comprehensive income, net of applicable taxes. Marketable equity securities are evaluated for OTTI based on the severity and duration of the impairment and, if deemed to be other than temporary, the declines in fair value are reflected in earnings as realized losses.
Federal Home Loan Bank stock	Federal Home Loan Bank stock The Company, as a member of the Federal Home Loan Bank of Boston (FHLBB) system, is required to maintain an investment in capital stock of the FHLBB. Based on the redemption provisions of the FHLBB, the stock has no quoted market value and is carried at cost. At its discretion, the FHLBB may declare dividends on the stock. The Company reviews its investment for impairment based on the ultimate recoverability of the cost basis in the FHLBB stock. As of December 31, 2015 and 2014 , no impairment has been recognized.
Loans held for sale	Loans held for sale Loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value in the aggregate. Net unrealized losses, if any, are recognized through a valuation allowance by charges to income.
Loans	Loans 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 and any deferred fees and costs on originated and 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 and to reverse all interest previously accrued against interest income. Past due status is based on contractual terms of the loan. The interest on non-accrual loans is accounted for on the cash-basis until qualifying for return to accrual. Loans are returned to accrual status when all the principal and interest amounts contractually due have been current for six consecutive months and future payments are reasonably assured.
Allowance for loan losses	Allowance for loan losses The allowance for loan losses is based on the size and the composition of the loan portfolio, delinquency levels, loss experience, economic conditions and other factors related to the collectability of the loan portfolio. For portfolios for which the Company had no prior loss experience, the national peer group losses for relevant portfolios generally over the years 2007-2014 were used. Charge-off factors are updated at least quarterly and management assesses them quantitatively on a quarterly basis. 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; however, because of the increase in risk exposures new to the Company, 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 extrapolated historical loss experience based on FDIC data for depository institutions with assets of $1 billion to $5 billion for periods ranging from 2007-2014, 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 regional 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 1 st or 2 nd 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 primarily include investment real estate and are generally secured by assignments of leases, real estate collateral and guarantees from sponsors or owners. 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 are adversely impacted by a downturn in the economy as evidenced by increased vacancy rates, which in turn, will 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 speculative real estate development loans for which payment is derived from 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 debt. 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 classic and collector automobile loans. A significant portion of the classic and collector automobile loan portfolio is comprised of geographically diverse loans originated by and purchased from a third party, who also provides collection services. While this portfolio generated minimal charge-offs, the provisions for loan losses reflect management’s estimate of inherent losses based on a review of regional and national historical losses of other institutions with similar portfolios. Allocated component The allocated component relates to loans that are on the watch list (non-accruing loans, partially charged-off non-accruing loans and accruing adversely-rated loans) and 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. 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 An unallocated component is maintained to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance reflects the margin of imprecision inherent in the underlying assumptions used in the methodologies for estimating allocated and general reserves in the portfolio.
Premises and equipment	Premises and equipment Land is carried at cost. Buildings, leasehold improvements and equipment are stated at cost, less accumulated depreciation and amortization, computed on the straight-line method over the estimated useful lives of the assets or the expected terms of the leases, if shorter. Expected terms include lease option periods to the extent that the exercise of such options is reasonably assured.
Goodwill and identifiable intangible assets	Goodwill and identifiable intangible assets Goodwill is the price paid in excess of the fair value of net assets acquired and is not amortized. Goodwill is evaluated for impairment at least annually, or more often if warranted, using a combined qualitative and quantitative impairment approach. The initial qualitative approach assesses whether the existence of events or circumstances led to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events and circumstances, the Company determines it is more likely than not that the fair value is less than carrying value, the two step quantitative impairment test is performed. Step one of the quantitative impairment test compares book value to the fair value of the reporting unit. If test one is failed, a more detailed analysis is performed, which involves measuring the excess of the fair value of the reporting unit, as determined in step one, over the aggregate fair value of the individual assets, liabilities, and identifiable intangibles as if the reporting unit was being acquired in a business combination. Identifiable intangible assets subject to amortization consist of the core deposit intangible acquired in the acquisition of Nantucket Bank which has an estimated life of approximately 5.5 years. Identifiable intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. The core deposit intangible is being amortized using the sum of the years' digits method over its estimated life.
Bank-owned life insurance	Bank-owned life insurance Bank-owned life insurance policies are reflected on the consolidated balance sheets at cash surrender value. Changes in cash surrender value are reflected in noninterest income in the consolidated statements of operations.
Non-marketable investments	Non-marketable investments The aggregate carrying amount of all cost and equity method investments included in other assets at December 31, 2015 and 2014 is $ 8.7 million and $ 6.1 million , respectively. The fair values of these investments are not readily available and are not evaluated for impairment unless there are identified events or changes in circumstances that may have a significant adverse effect on the fair value of the investments.
Interest rate swap agreements	Interest rate swap agreements For asset/liability management purposes, the Company periodically uses interest rate swap agreements to hedge various exposures or to modify interest rate characteristics of various balance sheet accounts. All interest rate swap agreements are recorded at fair value. Depending upon the intended use for the interest rate swap at inception, the Company designates the derivative as either an economic hedge of an asset or liability or a hedging instrument subject to the hedge accounting provisions. If the interest rate swap is not designated in a hedge relationship, gains or losses reflecting changes in fair value are recorded in earnings. Certain interest rate swap contracts are utilized to help commercial loan borrowers manage their interest rate risk. The interest rate swap contracts with commercial loan borrowers allow the borrowers to convert floating rate loan payments to fixed rate payments. When the Company enters into an interest rate swap contract with a commercial loan borrower, the Company concurrently enters into a matching interest rate swap with a correspondent bank counterparty in order to minimize interest rate risk to the Company. These interest rate derivative instruments are recorded on the consolidated balance sheets as either an asset or liability measured at fair value. These derivatives do not qualify for hedge accounting. As such, all changes in fair value of these derivative instruments are included in miscellaneous income. The Company pays and receives fees for entering into these contracts. The net fees are recognized in loan level derivative income when received.
Transfers of financial assets	Transfers of financial assets Transfers of an entire financial asset, a group of entire financial assets, or a participating interest in an entire financial asset are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. During the normal course of business, the Company may transfer a portion of a financial asset, for example, a participation loan. In order to be eligible for sales treatment, the transfered portion of the loan must meet the criteria of a participating interest. If it does not meet the criteria of a participating interest, the transfer must be accounted for as a secured borrowing. In order to meet the criteria for a participating interest, all cash flows from the loan must be divided proportionately, the rights of each loan holder must have the same priority, the loan holders must have no recourse to the transferor other than standard representations and warranties and no loan holder has the right to pledge or exchange the entire loan.
Retirement plan	Retirement plan The Company accounts for its defined benefit pension plan using an actuarial model that allocates pension costs over the service period of employees in the plan. The Company accounts for the over-funded or under-funded status of its defined benefit plan as an asset or liability on its consolidated balance sheets and recognizes changes in the funded status that are not reflected in net periodic pension cost as other comprehensive income or loss. The Company amended its defined benefit pension plan in 2013 freezing the plan to new participants and subsequently amended the plan and froze it for all participants effective October 31, 2014.
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. Dividend rights on unvested options/awards are forfeitable, therefor unvested awards/options are not considered outstanding in the computation of basic earnings per share. Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued, as well as any adjustment to income that would result from the assumed issuance. Potential common shares that may be issued by the Company relate to outstanding stock options and restricted stock awards and are determined using the treasury stock method.
Advertising costs	Advertising costs Advertising costs are expensed as incurred.
Stock-based Compensation Plans	Stock-based Compensation Plans The Company measures and recognizes compensation cost relating to stock-based payment transactions based on the grant-date fair value of the equity instruments issued. Stock-based compensation is recognized over the period the employee is required to provide services for the award. The Company uses the Black-Scholes option-pricing model to determine the fair value of stock options granted.
Employee Stock Ownership Plan	Employee Stock Ownership Plan Compensation expense for the Employee Stock Ownership Plan (ESOP) is recorded at an amount equal to the shares allocated by the ESOP multiplied by the average fair market value of the shares during the period. The Company recognizes compensation expense ratably over the year based upon the Company’s estimate of the number of shares expected to be allocated by the ESOP. Unearned compensation applicable to the ESOP is reflected as a reduction of stockholders' equity on the consolidated balance sheet. The difference between the average fair market value and the cost of the shares allocated by the ESOP is recorded as an adjustment to additional paid-in capital.
Income taxes	Income taxes Deferred tax assets and liabilities are reflected at currently enacted income tax rates applicable to the period in which the deferred tax assets or liabilities are expected to be realized or settled. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted accordingly through the provision for income taxes. The Company exercises significant judgment in evaluating the amount and timing of recognition of the resulting tax assets and liabilities. These judgments require the Company to make projections of future taxable income. These judgments and estimates, which are inherently subjective, are reviewed periodically as regulatory and business factors change. A valuation allowance related to deferred tax assets is established when, in the judgment of management, it is more likely than not that all or a portion of such deferred tax assets will not be realized. A tax position that meets the more likely than not recognition threshold is initially and subsequently measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position has met the more likely than not recognition threshold considers the facts, circumstances and information available at the reporting date and is subject to management’s judgment. There was no reserve for uncertain tax positions as of December 31, 2015 and 2014 respectively. The Company records interest and penalties as part of income tax expense. Income tax benefits related to stock compensation in excess of grant date fair value less any proceeds on exercise are recognized as an increase to additional paid-in capital upon vesting or exercising and delivery of the stock. Any income tax effects related to stock compensation that are less than grant date fair value less any proceeds on exercise would be recognized as a reduction of additional paid-in capital to the extent of previously recognized income tax benefits and then through income tax expense for the remaining amount.
Comprehensive Income	Comprehensive Income Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. Although certain changes in assets and liabilities are reported as a separate component of the equity section of the balance sheet, such items, along with net income, are components of comprehensive income.
Reclassification	Reclassification Certain amounts in the 2014 consolidated financial statements have been reclassified to conform to the 2015 presentation.
Recent Accounting Standards Updates	RECENT ACCOUNTING STANDARDS UPDATES In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update Update No. 2014-09 issued to address the previous revenue recognition requirements in GAAP that differ from those in International Financial Reporting Standards (IFRS). Accordingly, the FASB and the International Accounting Standards Board (IASB) initiated a joint project to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and IFRS. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. For public entities, the standard is effective for annual and interim periods beginning after December 15, 2017, and calendar year-end public entities will apply it in the quarter that ends March 31, 2018. Early adoption is not permitted. We are currently assessing the potential impact of this amendment on our consolidated financial statements. In September 2015, FASB issued ASU 2015-16, Business Combinations (Topic 805). The amendments in this Update require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. In addition, the amendments require that the acquirer record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. For public business entities, the amendments are effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2016, and interim periods within fiscal years beginning after December 15, 2017. The amendments should be applied prospectively to adjustments to provisional amounts that occur after the effective date of this Update with earlier application permitted for financial statements that have not yet been made available for issuance. 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. The impact of the change in equity investments will depend on maket conditions but if applied in 2015, would have resulted in a loss of $3.7 million (after tax) being recognized in net income versus other comprehensive income. See the Consolidated Statement of Comprehensive Income (Loss). 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. The Update will be effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Management is currently evaluating the impact to the consolidated financial statements of adopting this Update.

Basis of Presentation and Con29

Basis of Presentation and Consolidation (Tables)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Finite-Lived Intangible Assets	The core deposit intangible is being amortized using the sum of the years' digits method over its estimated life. Information related to the core deposit intangible, including the estimated annual amortization expense, is summarized below: (In thousands) Balance at December 31, 2013 $ — Acquisition of Nantucket Bank 6,040 Amortization (1,808 ) Balance at December 31, 2014 4,232 Amortization (1,607 ) Balance at December 31, 2015 $ 2,625
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Estimated amortization expense for the years ending December 31, 2016 $ 1,225 2017 843 2018 461 2019 96 Total remaining $ 2,625

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The amortized cost and estimated fair value of securities available for sale and held to maturity, with gross unrealized gains and losses, follow: December 31, 2015 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 $ 13,126 $ — $ (195 ) $ 12,931 Other asset-backed securities 11,395 — (142 ) 11,253 Total other mortgage- and asset-backed securities 24,521 — (337 ) 24,184 State and political 16,016 354 (55 ) 16,315 Financial services: Banks 18,813 138 (90 ) 18,861 Diversified financial entities 23,124 349 (173 ) 23,300 Insurance and REITs 16,883 1 (282 ) 16,602 Total financial services 58,820 488 (545 ) 58,763 Other corporate: Industrials 55,470 306 (1,244 ) 54,532 Utilities 31,952 7 (1,639 ) 30,320 Total other corporate 87,422 313 (2,883 ) 84,852 Total debt securities 186,779 1,155 (3,820 ) 184,114 Marketable equity securities: Mutual funds: Global equity 5,000 388 — 5,388 Domestic community 3,216 70 (13 ) 3,273 Global asset allocation 42,396 3 (3,484 ) 38,915 Total marketable equity securities 50,612 461 (3,497 ) 47,576 Total securities available for sale $ 237,391 $ 1,616 $ (7,317 ) $ 231,690 December 31, 2014 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) Securities Available for Sale: Debt securities: U.S. Treasury $ 13,037 $ 182 $ — $ 13,219 Government-sponsored enterprises 26,335 131 (29 ) 26,437 Government-sponsored mortgage-backed and collateralized mortgage obligations 160,091 756 (294 ) 160,553 Other mortgage- and asset-backed: Privately issued commercial mortgage-backed securities 22,100 30 (201 ) 21,929 SBA asset-backed securities 27,765 308 (27 ) 28,046 Other asset-backed securities 16,235 — (43 ) 16,192 Total other mortgage- and asset-backed securities 66,100 338 (271 ) 66,167 State and political 15,619 567 (3 ) 16,183 Financial services: Banks 12,364 531 (6 ) 12,889 Diversified financial entities 15,796 354 (18 ) 16,132 Insurance and REITs 9,387 138 (9 ) 9,516 Total financial services 37,547 1,023 (33 ) 38,537 Other corporate: Industrials 34,408 681 (54 ) 35,035 Utilities 16,873 265 (120 ) 17,018 Total other corporate 51,281 946 (174 ) 52,053 Total debt securities 370,010 3,943 (804 ) 373,149 Marketable equity securities: Mutual funds: Global equity 5,000 623 — 5,623 Domestic community 3,216 86 (5 ) 3,297 Global asset allocation 32,956 1,498 (76 ) 34,378 Total marketable equity securities 41,172 2,207 (81 ) 43,298 Total securities available for sale $ 411,182 $ 6,150 $ (885 ) $ 416,447
Schedule of Held-to-maturity Securities Reconciliation	Securities Held to Maturity: Debt securities: U.S. Treasury $ 636 $ — $ (2 ) $ 634 Government-sponsored enterprises 28,256 94 (126 ) 28,224 Government-sponsored mortgage-backed and collateralized mortgage obligations 155,232 10 (832 ) 154,410 SBA asset-backed securities 16,017 — (59 ) 15,958 Total securities held to maturity $ 200,141 $ 104 $ (1,019 ) $ 199,226
Investments Classified by Contractual Maturity Date	The amortized cost and estimated fair value of debt securities by contractual maturity at December 31, 2015 follow. 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. Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value (In thousands) Within 1 year $ 6,572 $ 6,578 $ 5,667 $ 5,667 After 1 year through 5 years 85,860 85,640 14,202 14,109 After 5 years through 10 years 62,163 60,144 9,023 9,082 After 10 years 7,663 7,568 — — 162,258 159,930 28,892 28,858 Mortgage- and asset-backed securities and collateralized mortgage obligations amortizing monthly 24,521 24,184 171,249 170,368 Total debt securities $ 186,779 $ 184,114 $ 200,141 $ 199,226
Available-for-sale Securities	December 31, 2014 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: Government-sponsored enterprises $ (12 ) $ 5,932 $ (17 ) $ 1,080 Government-sponsored mortgage-backed and collateralized mortgage obligations (190 ) 93,364 (104 ) 8,425 Other mortgage- and asset-backed: Privately issued commercial mortgage- backed securities (69 ) 9,412 (132 ) 8,759 SBA asset-backed securities (27 ) 5,529 — — Other asset-backed securities (43 ) 16,192 — — Total other mortgage- and asset-backed securities (139 ) 31,133 (132 ) 8,759 State and political (3 ) 1,955 — Financial services: Banks (6 ) 2,907 — — Diversified financial entities (18 ) 7,676 — — Insurance and REITs (9 ) 4,177 — — Total financial services (33 ) 14,760 — — Other corporate: Industrials (54 ) 9,575 — — Utilities (120 ) 7,291 — — Total other corporate (174 ) 16,866 — — Total debt securities (551 ) 164,010 (253 ) 18,264 Marketable equity securities: Mutual funds: Domestic community — — (5 ) 462 Global asset allocation (76 ) 7,057 — — Total marketable equity securities (76 ) 7,057 (5 ) 462 Total temporarily impaired securities $ (627 ) $ 171,067 $ (258 ) $ 18,726 nformation 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: December 31, 2015 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 $ (84 ) $ 5,166 $ (111 ) $ 7,765 Other asset-backed securities (142 ) 11,253 — — Total other mortgage- and asset-backed securities (226 ) 16,419 (111 ) 7,765 State and political (55 ) 3,324 — — Financial services: Banks (90 ) 14,070 — — Diversified financial entities (173 ) 15,397 — — Insurance and REITs (282 ) 14,487 — — Total financial services (545 ) 43,954 — — Other corporate: Industrials (957 ) 43,848 (287 ) 395 Utilities (1,387 ) 25,353 (252 ) 1,618 Total other corporate (2,344 ) 69,201 (539 ) 2,013 Total debt securities (3,170 ) 132,898 (650 ) 9,778 Marketable equity securities: Mutual funds: Domestic community — — (13 ) 453 Global asset allocation (3,484 ) 36,609 — — Total marketable equity securities (3,484 ) 36,609 (13 ) 453 Total temporarily impaired available-for-sale securities $ (6,654 ) $ 169,507 $ (663 ) $ 10,231
Held-to-maturity Securities	Securities Held to Maturity: Debt securities: U.S. Treasury $ (2 ) $ 634 $ — $ — Government-sponsored enterprises (126 ) 14,084 — — Government-sponsored mortgage-backed and collateralized mortgage obligations (832 ) 144,820 — — SBA asset-backed securities (59 ) 15,958 — — Total temporarily impaired held-to-maturity securities $ (1,019 ) $ 175,496 $ — $ —

Loans and The Allowance for L31

Loans and The Allowance for Loan Loss (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	A summary of the balances of loans follows: December 31, 2015 2014 (In thousands) Real estate: 1-4 family residential $ 599,938 $ 460,273 Home equity 77,399 61,750 Commercial real estate 561,203 387,807 Construction 79,773 53,606 1,318,313 963,436 Commercial business 182,677 151,823 Consumer 38,186 31,778 Total loans 1,539,176 1,147,037 Allowance for loan losses (17,102 ) (12,973 ) Discount and fair value adjustments on purchased loans (1,959 ) (2,970 ) Deferred loan costs and fees, net 3,160 1,820 Loans, net $ 1,523,275 $ 1,132,914
Activity in Allowance for Loan Losses	Activity in the allowance for loan losses for the year ended December 31, 2015 , 2014 and 2013 and allocation of the allowance to loan segments as of December 31, 2015 and 2014 follows: 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Unallocated Total (In thousands) 2015 Beginning balance $ 3,222 $ 340 $ 3,551 $ 1,056 $ 3,410 $ 736 $ 658 $ 12,973 Provision (credit) for loan losses 612 296 3,596 308 (571 ) 79 (230 ) 4,090 Loans charged-off — — — — — (43 ) — (43 ) Recoveries 82 — — — — — — 82 Ending Balance $ 3,916 $ 636 $ 7,147 $ 1,364 $ 2,839 $ 772 $ 428 $ 17,102 2014 Beginning balance $ 2,835 $ 247 $ 2,608 $ 303 $ 2,416 $ 574 $ 688 $ 9,671 Provision (credit) for loan losses 405 93 943 753 994 223 (30 ) 3,381 Loans charged-off (18 ) — — — — (61 ) — (79 ) Recoveries — — — — — — — — Ending Balance $ 3,222 $ 340 $ 3,551 $ 1,056 $ 3,410 $ 736 $ 658 $ 12,973 2013 Beginning balance $ 2,725 $ 316 $ 1,343 $ 106 $ 565 $ 313 $ 182 $ 5,550 Provision (credit) for loan losses 39 (69 ) 1,265 197 1,851 305 506 4,094 Loans charged-off (165 ) — — — — (44 ) — (209 ) Recoveries 236 — — — — — — 236 Ending Balance $ 2,835 $ 247 $ 2,608 $ 303 $ 2,416 $ 574 $ 688 $ 9,671
Allowance for Credit Losses on Financing Receivables	Additional information pertaining to the allowance for loan losses at December 31, 2015 and December 31, 2014 is as follows: 1-4 Family Home Commercial Construction Commercial Consumer Unallocated Total (In thousands) December 31, 2015 Allowance related to impaired loans $ — $ — $ 384 $ — $ 10 $ 10 $ — $ 404 Allowance related to non-impaired loans 3,916 636 6,763 1,364 2,829 762 428 16,698 Total allowance for loan losses $ 3,916 $ 636 $ 7,147 $ 1,364 $ 2,839 $ 772 $ 428 $ 17,102 Impaired loans $ 6,114 $ 270 $ 4,631 $ — $ 10 $ 145 $ — $ 11,170 Non-impaired loans 593,824 77,129 556,572 79,773 182,667 38,041 — 1,528,006 Total loans $ 599,938 $ 77,399 $ 561,203 $ 79,773 $ 182,677 $ 38,186 $ — $ 1,539,176 December 31, 2014 Allowance related to impaired loans $ — $ — $ — $ — $ — $ — $ — $ — Allowance related to non-impaired loans 3,222 340 3,551 1,056 3,410 736 658 12,973 Total allowance for loan losses $ 3,222 $ 340 $ 3,551 $ 1,056 $ 3,410 $ 736 $ 658 $ 12,973 Impaired loans $ 4,419 $ 578 $ — $ — $ — $ 27 $ — $ 5,024 Non-impaired loans 455,854 61,172 387,807 53,606 151,823 31,751 — 1,142,013 Total loans $ 460,273 $ 61,750 $ 387,807 $ 53,606 $ 151,823 $ 31,778 $ — $ 1,147,037
Past Due Financing Receivables	The following is a summary of past due and non-accrual loans, by loan class, at December 31, 2015 and December 31, 2014 : 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) December 31, 2015 Real estate: 1-4 family residential $ 2,287 $ — $ 990 $ 3,277 $ 5,688 Home equity 1,031 19 176 1,226 270 Commercial real estate — 1,249 — 1,249 4,631 Commercial business 23 — — 23 10 Consumer 3 80 120 203 145 Total $ 3,344 $ 1,348 $ 1,286 $ 5,978 $ 10,744 December 31, 2014 Real estate: 1-4 family residential $ 3,137 $ 522 $ 1,370 $ 5,029 $ 3,876 Home equity 680 — 475 1,155 578 Consumer 217 — 5 222 27 Total $ 4,034 $ 522 $ 1,850 $ 6,406 $ 4,481
Impaired Financing Receivables	The following is a summary of information pertaining to impaired loans by loan segment at the dates indicated: Recorded Investment Unpaid Principal Balance Related Allowance December 31, 2015 (In thousands) Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 6,114 $ 6,824 $ — Home equity 270 425 — Consumer 35 39 — Total 6,419 7,288 — Impaired loans with a valuation allowance: Commercial real estate 4,631 4,631 384 Commercial business 10 11 10 Consumer 110 110 10 Total 4,751 4,752 404 Total impaired loans $ 11,170 $ 12,040 $ 404 December 31, 2014 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,419 $ 5,211 $ — Home Equity 578 804 — Consumer 27 25 — Total impaired loans $ 5,024 $ 6,040 $ — by segment, for the years ended December 31, 2015 , 2014 and 2013 : Average Recorded Investment Interest Income Recognized 2015 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,869 $ 270 Home equity 575 14 Consumer 34 4 Impaired loans with a valuation allowance: Commercial real estate 926 161 Commercial business 2 1 Consumer 44 2 Total $ 6,450 $ 452 2014 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 4,076 $ 213 Home equity 476 17 Consumer 34 2 Total $ 4,586 $ 232 2013 Impaired loans without a valuation allowance: Real estate: 1-4 family residential $ 2,586 $ 61 Home equity 32 — Total $ 2,618 $ 61
Troubled Debt Restructurings on Financing Receivables	Troubled debt restructurings entered into during the years ended December 31, 2015 and 2014: Number of contracts Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment 2015 (Dollars in thousands) Real estate: 1-4 family residential 4 $ 728 $ 750 2014: Real estate: 1-4 family residential 1 $ 181 $ 193
Financing Receivable Credit Quality Indicators	The following tables present the Company’s loans by risk rating at December 31, 2015 and December 31, 2014 : 1-4 Family Residential Home Equity Commercial Real Estate Construction Commercial Business Consumer Total Loans (In thousands) December 31, 2015 Loans rated 1 - 6 $ 1,950 $ 465 $ 548,360 $ 79,773 $ 181,792 $ 6 $ 812,346 Loans rated 7 4,461 321 7,765 — 874 — 13,421 Loans rated 8 1,592 144 5,078 — — 149 6,963 Loans rated 9 701 — — — 11 — 712 Loans rated 10 — — — — — — — Loans not rated 591,234 76,469 — — — 38,031 705,734 $ 599,938 $ 77,399 $ 561,203 $ 79,773 $ 182,677 $ 38,186 $ 1,539,176 December 31, 2014 Loans rated 1 - 6 $ 3,381 $ 473 $ 387,651 $ 53,606 $ 150,960 $ 5 $ 596,076 Loans rated 7 3,095 852 156 — 863 — 4,966 Loans rated 8 1,331 — — — — 31 1,362 Loans rated 9 709 — — — — — 709 Loans rated 10 — — — — — — — Loans not rated 451,757 60,425 — — — 31,742 543,924 $ 460,273 $ 61,750 $ 387,807 $ 53,606 $ 151,823 $ 31,778 $ 1,147,037

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Premises and Equipment	A summary of the cost and accumulated depreciation and amortization of premises and equipment follows: December 31, Estimated Useful Lives 2015 2014 (In thousands) Land $ 4,087 $ 4,087 Buildings 10,322 10,293 5 to 40 years Leasehold improvements 7,727 6,109 5 to 10 years Furniture and fixtures 2,601 2,014 3 to 5 years Technology equipment 5,088 4,266 1 to 3 years Construction in progress 70 75 Property, plant and equipment, gross 29,895 26,844 Less accumulated depreciation and amortization (9,880 ) (8,056 ) Property, plant and equipment, net $ 20,015 $ 18,788

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2015
Banking and Thrift [Abstract]
Schedule of Deposit Balances	A summary of deposit balances, by type, is as follows: December 31, 2015 2014 (In thousands) NOW and demand $ 288,143 $ 245,117 Regular savings 287,344 303,834 Money market 368,050 280,139 Brokered money market 41,807 23,166 Total non-certificate accounts 985,344 852,256 Term certificates of $250,000 or more 65,364 56,325 Term certificates less than $250,000 246,614 245,430 Brokered certificates of deposit 136,527 58,705 Total certificate accounts 448,505 360,460 Total deposits $ 1,433,849 $ 1,212,716
Schedule of Contractual Maturities of Deposits and Weighted Average Rate	At December 31, 2015 , the scheduled maturities of term certificate accounts, including brokered deposits, are as follows: Amount Weighted Average Rate (Dollars in thousands) 2016 239,134 0.62 % 2017 86,464 1.10 2018 40,570 1.37 2019 44,630 1.90 2020 37,707 1.92 $ 448,505 1.01 %

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Maturities of Long-term Debt	Long-term debt consists of the following FHLBB advances: December 31, 2015 December 31, 2014 Amount Weighted Average Rate Amount Weighted Average Rate (Dollars in thousands) Fixed-rate advances maturing: 2016 $ 10,000 2.29 % $ 10,000 2.29 % 2017 15,000 1.99 15,000 1.99 2018 20,000 2.23 10,000 3.16 2020 10,000 1.65 — — $ 55,000 2.07 % $ 35,000 2.41 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Allocation of federal and state income taxes between current and deferred portions is as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Current tax provision: Federal $ 2,933 $ 2,695 $ 960 State 206 240 172 3,139 2,935 1,132 Deferred tax provision (benefit): Federal 7 (3,183 ) (1,609 ) State (148 ) (1,014 ) (502 ) Federal and State (141 ) (4,197 ) (2,111 ) Change in valuation reserve (161 ) 640 695 Deferred income tax benefit (302 ) (3,557 ) (1,416 ) Provision (benefit) for income taxes $ 2,837 $ (622 ) $ (284 )
Schedule of Effective Income Tax Rate Reconciliation	The reasons for the differences between the statutory federal income tax provision and the actual tax provision (benefit) are summarized as follows: Years Ended December 31, 2015 2014 2013 (Dollars in thousands) Statutory federal tax provision (benefit) at 34% $ 3,429 $ (274 ) $ 809 Increase (decrease) resulting from: State taxes, net of federal tax benefit 39 (511 ) (218 ) Dividends received deduction (211 ) (201 ) (134 ) Tax-exempt bank-owned life insurance (351 ) (404 ) (984 ) Tax-exempt interest (222 ) (277 ) (224 ) Change in valuation reserve (161 ) 640 695 Nondeductible IPO costs — 202 — Other, net 314 203 (228 ) Tax provision (benefit) $ 2,837 $ (622 ) $ (284 ) Effective tax rates 28.2 % 77.3 % (11.9 )%
Schedule of Deferred Tax Assets and Liabilities	he components of the net deferred tax asset (liability) are as follows: December 31, 2015 2014 (In thousands) Deferred tax assets: Federal $ 12,091 $ 8,453 State 3,188 2,543 Deferred tax assets, gross 15,279 10,996 Valuation reserve (1,966 ) (2,012 ) Deferred tax assets, net 13,313 8,984 Deferred tax liabilities: Federal (2,138 ) (2,429 ) State (510 ) (322 ) Deferred tax liabilities, gross (2,648 ) (2,751 ) Net deferred tax asset $ 10,665 $ 6,233 The tax effects of each item that give rise to deferred tax assets (liabilities) are as follows: December 31, 2015 2014 (In thousands) Deferred tax assets: Depreciation and amortization $ 929 $ 603 Employee benefit plans and share-based compensation plans 901 682 Allowance for loan losses 6,831 5,181 Contribution carryover 2,675 3,281 Net unrealized loss on securities held as, or transferred from, available for sale 1,748 — Net unrealized losses on defined benefit pension plan 1,052 543 Other 159 71 Valuation reserve (1,966 ) (2,012 ) Deferred tax liabilities: Deferred loan origination costs (1,664 ) (243 ) Net unrealized gain on securities available for sale — (1,873 ) Net deferred tax asset $ 10,665 $ 6,233 A summary of the change in the net deferred tax asset (liability) is as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Balance at beginning of year $ 6,233 $ 2,831 $ (3,165 ) Deferred tax benefit 302 3,557 1,416 Tax effect of changes in accumulated other comprehensive income 4,130 (155 ) 4,580 Balance at end of year $ 10,665 $ 6,233 $ 2,831
Schedule of Changes in Deferred Tax Assets Valuation Allowance	A summary of the change in valuation allowance is as follows: For the Year Ended December 31, 2015 Federal State Total (In thousands) Balance at beginning of year $ (544 ) $ (1,468 ) $ (2,012 ) Change through the income statement 344 (183 ) 161 Change through other comprehensive income — (115 ) (115 ) Balance at end of year $ (200 ) $ (1,766 ) $ (1,966 )

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2015
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 December 31, 2015 and 2014 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.: December 31, 2015 Total capital (to risk weighted assets) $ 407,444 24.8 % $ 131,231 8.0 % 164,039 10.0 % Tier 1 capital (to risk weighted assets) 390,342 23.8 98,423 6.0 131,231 8.0 Common equity Tier 1(to risk weighted assets) 390,342 23.8 73,818 4.5 106,625 6.5 Tier 1 capital (to average assets) 390,342 19.6 79,658 4.0 99,573 5.0 December 31, 2014 Total capital (to risk weighted assets) 409,545 32.6 100,513 8.0 N/A N/A Tier 1 capital (to risk weighted assets) 395,615 31.5 50,257 4.0 N/A N/A Common equity Tier 1(to risk weighted assets) N/A N/A N/A N/A N/A N/A Tier 1 capital (to average assets) 395,615 23.3 67,820 4.0 N/A N/A Blue Hills Bank: December 31, 2015 Total capital (to risk weighted assets) 296,309 18.1 130,832 8.0 163,540 10.0 Tier 1 capital (to risk weighted assets) 279,207 17.1 98,124 6.0 130,832 8.0 Common equity Tier 1(to risk weighted assets) 279,207 17.1 73,593 4.5 106,301 6.5 Tier 1 capital (to average assets) 279,207 14.0 79,867 4.0 99,608 5.0 December 31, 2014 Total capital (to risk weighted assets) 283,443 22.7 99,973 8.0 124,966 10.0 Tier 1 capital (to risk weighted assets) 269,513 21.6 49,987 4.0 74,980 6.0 Common equity Tier 1(to risk weighted assets) N/A N/A N/A N/A N/A N/A Tier 1 capital (to average assets) 269,513 15.9 67,707 4.0 84,634 5.0

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan	Years Ended December 31, 2015 2014 2013 (In thousands) Change in plan assets: Fair value of plan assets at beginning of year $ 9,443 $ 9,535 $ 9,331 Actual return (loss) on plan assets (304 ) 391 1,513 Benefits paid (325 ) (483 ) (1,309 ) Fair value of plan assets at end of year 8,814 9,443 9,535 Change in benefit obligation: Benefit obligation at beginning of year 10,135 9,287 10,818 Service cost — 484 708 Interest cost 401 407 423 Actuarial loss (gain) 561 2,230 (1,353 ) Benefits paid (325 ) (483 ) (1,309 ) Curtailment gain — (1,790 ) — Benefit obligation at end of year 10,772 10,135 9,287 Funded status and prepaid expense (accrued liability) at end of year $ (1,958 ) $ (692 ) $ 248 Accumulated benefit obligation at end of year $ 10,772 $ 10,135 $ 7,507
Schedule of Assumptions Used	The assumptions used to determine net periodic pension cost are as follows: Years Ended December 31, 2015 2014 2013 Discount rate 4.00 % 4.25 % 4.00 % Expected long-term rate of return on plan assets 8.00 % 8.00 % 8.00 % Rate of compensation increase n/a n/a 3.00 % At December 31, 2015 and 2014, the discount rate used to determine the benefit obligation was as follows: December 31, 2015 2014 Discount rate 4.01 % 4.00 % Rate of compensation increase n/a n/a
Schedule of Net Benefit Costs	The components of net periodic pension cost (benefit) are as follows: Years Ended December 31, 2015 2014 2013 (In thousands) Service cost $ — $ 484 $ 708 Interest cost 401 407 423 Expected return on plan assets (745 ) (735 ) (728 ) Amortization of net actuarial loss (gain) 110 (70 ) 104 Settlement gain — — (107 ) Curtailment gain — (1,304 ) — Net periodic pension cost (benefit) $ (234 ) $ (1,218 ) $ 400
Schedule of Allocation of Plan Assets	The fair value of major categories of the Company’s pension plan assets are summarized below: Level 1 Level 2 Level 3 Total Fair Value (In thousands) December 31, 2015 Collective funds $ 1,126 $ 4,266 $ — $ 5,392 Equity securities 1,566 — — 1,566 Mutual funds 1,046 — — 1,046 Hedge funds — — 660 660 Short-term investments 150 — — 150 $ 3,888 $ 4,266 $ 660 $ 8,814 December 31, 2014 Collective funds $ 770 $ 4,276 $ — $ 5,046 Equity securities 2,178 — — 2,178 Mutual funds 1,330 134 — 1,464 Hedge funds — — 659 659 Short-term investments 96 — — 96 $ 4,374 $ 4,410 $ 659 $ 9,443
Schedule of Expected Benefit Payments	Estimated future benefit payments, assuming employees retire at age 65 and take normal distribution payments, are as follows: Amount Year Ending December 31, (In thousands) 2016 $ 495 2017 679 2018 934 2019 543 2020 655 2021-2025 3,239
Employee Stock Ownership Plan (ESOP) Disclosures	Shares held by the ESOP include the following: December 31, 2015 December 31, 2014 Allocated 75,912 — Committed to be allocated 75,912 75,912 Unallocated 2,124,846 2,201,433 2,276,670 2,277,345

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
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 in 2015 : Date of grant October 7, 2015 Options granted 2,434,000 Vesting period (years) 5 Expiration date October 7, 2025 Expected volatility 28.85 % Expected life (years) 6.5 Expected dividend yield 0.54 % Risk free interest rate 1.55 % Fair value per option $ 4.23
Schedule of Share-based Compensation, Stock Options, Activity	A summary of the status of the Company's stock option grants for the year ended December 31, 2015 , is presented in the table below: Options Stock Option Awards Weighted Average Exercise Price Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value Balance at January 1, 2015 — $ — — $ — Granted 2,434,000 14.07 9.78 3,018,160 Balance at December 31, 2015 2,434,000 $ 14.07 9.78 $ 3,018,160 Outstanding and expected to vest at December 31, 2015 2,434,000 $ 14.07 9.78 $ 3,018,160 Exercisable at December 31, 2015 — $ — — $ — Unrecognized compensation cost $9,822,000 Weighted average remaining recognition period (years) 4.77
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 year ended December 31, 2015 : Outstanding Restricted Stock Awards Weighted Average Grant Price Non-vested stock awards at January 1, 2015 — $ — Granted 983,175 14.07 Non-vested stock awards at December 31, 2015 983,175 $ 14.07 Unrecognized compensation cost inclusive of directors' fees $13,182,000 Weighted average remaining recognition period (years) 4.77

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	(Dollars in thousands, except per share amounts) 2015 Net income applicable to common stock $ 7,227 Average number of common shares outstanding 28,228,425 Less: Average unallocated ESOP shares (2,163,478 ) Average number of common shares outstanding used to calculate basic earnings per common share 26,064,947 Effect of dilutive unvested restricted stock awards 4,642 Average number of common shares outstanding used to calculate diluted earnings per common share 26,069,589 Earnings per common share: Basic $ 0.28 Diluted $ 0.28

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Fair Value, Off-balance Sheet Risks	Financial instruments whose contract amounts represent credit risk consist of: December 31, 2015 2014 (In thousands) Commitments to originate loans $ 69,554 $ 44,504 Letters of credit 3,571 7,133 Unused lines-of-credit: Commercial 128,748 81,607 Home equity 84,374 37,580 Consumer 16,033 16,057 Undisbursed construction loans 4,844 6,679
Schedule of Future Minimum Rental Payments for Operating Leases	Pursuant to the terms of noncancelable lease agreements in effect at December 31, 2015 , pertaining to premises, future minimum rent commitments are as follows: Year Ending December 31, Amount (In thousands) 2016 $ 1,801 2017 1,859 2018 1,839 2019 1,595 2020 1,499 Thereafter 8,879 $ 17,472

Interest Rate Swap Agreements (

Interest Rate Swap Agreements (Tables)	12 Months Ended
	Dec. 31, 2015
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 December 31, 2015 and 2014 . Derivative Gains Derivative Losses Notional Amount Fair Value Notional Amount Fair Value (In thousands) December 31, 2015 Economic hedges: Commercial loan level interest rate swap agreements $ 282,546 $ 7,956 $ 282,546 $ 8,411 Other contracts 8,300 6 12,698 78 Total derivatives $ 290,846 $ 7,962 $ 295,244 $ 8,489 December 31, 2014 Economic hedges: Commercial loan level interest rate swap agreements $ 202,970 $ 5,446 $ 202,970 $ 5,759 Other contracts 8,616 8 8,287 83 Total derivatives $ 211,586 $ 5,454 $ 211,257 $ 5,842

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
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) December 31, 2015 Assets Securities available for sale: Debt securities $ — $ 184,114 $ — $ 184,114 Marketable equity securities 47,576 — — 47,576 Derivative assets — 7,962 — 7,962 Total assets $ 47,576 $ 192,076 $ — $ 239,652 Liabilities Derivative liabilities $ — $ 8,489 $ — $ 8,489 December 31, 2014 Assets Securities available for sale: Debt securities $ 13,219 $ 359,930 $ — $ 373,149 Marketable equity securities 43,298 — — 43,298 Derivative assets — 5,454 — 5,454 Total assets $ 56,517 $ 365,384 $ — $ 421,901 Liabilities Derivative liabilities $ — $ 5,842 $ — $ 5,842
Fair Value, by Balance Sheet Grouping	Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) December 31, 2015 Financial assets: Cash and cash equivalents $ 33,298 $ 33,298 $ — $ — $ 33,298 Securities available for sale 231,690 47,576 184,114 — 231,690 Securities held to maturity 200,141 634 198,592 — 199,226 Federal Home Loan Bank stock 13,567 — — 13,567 13,567 Loans and loans held for sale, net 1,536,152 — — 1,538,809 1,538,809 Accrued interest receivable 5,344 — — 5,344 5,344 Financial liabilities: Deposits 1,433,849 — — 1,434,179 1,434,179 Borrowings 260,000 — 260,244 — 260,244 On-balance sheet derivative financial instruments: Interest rate swap agreements: Assets 7,962 — 7,962 — 7,962 Liabilities 8,489 — 8,489 — 8,489 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (In thousands) December 31, 2014 Financial assets: Cash and cash equivalents $ 60,146 $ 60,146 $ — $ — $ 60,146 Securities available for sale 416,447 56,517 359,930 — 416,447 Federal Home Loan Bank stock 11,702 — — 11,702 11,702 Loans and loans held for sale, net 1,147,505 — — 1,132,024 1,132,024 Accrued interest receivable 4,433 — — 4,433 4,433 Financial liabilities: Deposits 1,212,716 — — 1,214,251 1,214,251 Borrowings 75,000 — 76,074 — 76,074 On-balance sheet derivative financial instruments: Interest rate swap agreements: Assets 5,454 — 5,454 — 5,454 Liabilities 5,842 — 5,842 — 5,842

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The components of accumulated other comprehensive income, included in equity, are as follows: December 31, 2015 2014 (In thousands) Securities available for sale: Net unrealized gain (loss) $ (5,701 ) $ 5,265 Tax effect 1,945 (1,873 ) Net-of-tax amount (3,756 ) 3,392 Securities held to maturity: Net unrealized gain on transferred securities 571 — Tax effect (197 ) — Net-of-tax amount 374 — Defined benefit pension plan: Unrecognized net actuarial loss (2,858 ) (1,358 ) Tax effect 1,052 543 Net-of-tax amount (1,806 ) (815 ) $ (5,188 ) $ 2,577 Changes in accumulated other comprehensive income (loss) by component follows: Securities Available for Sale Securities Held to Maturity Defined Benefit Pension Plan Total Year Ended December 31, 2015 Beginning balance $ 3,392 $ — $ (815 ) $ 2,577 Other comprehensive income (loss) before reclassifications (8,332 ) — (1,610 ) (9,942 ) Realized gains reclassified (1,968 ) — — (1,968 ) Amortization of actuarial losses — — 110 110 Unrealized gains on securities reclassified as held to maturity (666 ) 666 — — Amortization of amounts previously recorded upon transfer to held-to-maturity from available-for-sale — (95 ) — (95 ) Tax effects 3,818 (197 ) 509 4,130 Net current-period other comprehensive income (loss) (7,148 ) 374 (991 ) (7,765 ) Ending balance $ (3,756 ) $ 374 $ (1,806 ) $ (5,188 ) Year ended December 31, 2014 Beginning balance $ 1,983 $ — $ 482 $ 2,465 Other comprehensive income (loss) before reclassifications 4,942 — (2,090 ) 2,852 Realized gains reclassified (2,515 ) — — (2,515 ) Amortization of actuarial gains — — (70 ) (70 ) Tax effects (1,018 ) — 863 (155 ) Net current-period other comprehensive income (loss) 1,409 — (1,297 ) 112 Ending balance $ 3,392 $ — $ (815 ) $ 2,577 Year Ended December 31, 2013 Beginning balance $ 10,805 $ — $ (802 ) $ 10,003 Other comprehensive income (loss) before reclassifications (9,256 ) — 2,033 (7,223 ) Realized gains reclassified (4,999 ) — — (4,999 ) Amortization of actuarial losses — — 104 104 Tax effects 5,433 — (853 ) 4,580 Net current-period other comprehensive income (loss) (8,822 ) — 1,284 (7,538 ) Ending balance $ 1,983 $ — $ 482 $ 2,465

Condensed Financial Statement44

Condensed Financial Statements of Parent Company (Tables)	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheet	Financial information pertaining only to Blue Hills Bancorp, Inc. is as follows: December 31, BALANCE SHEETS 2015 2014 (In thousands) Assets Cash balances at Blue Hills Bank $ 100,965 $ 121,632 Total cash and cash equivalents 100,965 121,632 Investment in subsidiaries 311,357 308,606 Other assets 7,993 3,561 Total assets $ 420,315 $ 433,799 Liabilities and Stockholders' Equity Liability to ESOP 21,459 21,925 Accrued expenses 27 $ 268 Stockholders' equity 398,829 411,606 Total liabilities and stockholders' equity $ 420,315 $ 433,799
Condensed Statements of Operations	Years Ended December 31, 2015 2014 2013 STATEMENTS OF OPERATIONS (In thousands) Total income $ 713 $ 331 $ — Operating expenses 1,860 9,432 — Loss before income taxes and equity in undistributed net income of subsidiaries (1,147 ) (9,101 ) — Applicable income tax benefit (1,112 ) (3,277 ) — Loss before equity in income of subsidiaries (35 ) (5,824 ) — Equity in undistributed net income of subsidiaries 7,975 5,972 2,663 Net income (loss) $ 7,940 $ 148 $ 2,663
Condensed Cash Flow Statement	Years Ended December 31, 2015 2014 2013 STATEMENTS OF CASH FLOWS (In thousands) Cash flows from operating activities: Net income (loss) $ 7,940 $ 148 2,663 Adjustments to reconcile net income (loss) to net cash provided by used for operating activities: Equity in undistributed net income of subsidiaries (7,975 ) (5,972 ) (2,663 ) Issuance of common stock to Charitable Foundation — 6,943 — Net change in other assets (2,221 ) (2,062 ) (44 ) Net change in other liabilities (241 ) 267 — Net cash used for operating activities (2,497 ) (676 ) (44 ) Cash flows from investing activities: Investment in Blue Hills Bank (3,929 ) (161,820 ) — Net cash used for investing activities (3,929 ) (161,820 ) — Cash flows from financing activities: Proceeds from the issuance of common stock — 274,143 — Redemption of SBLF preferred stock — (18,724 ) — Repurchase of common stock (13,121 ) — — Common and Preferred Stock dividends paid (1,120 ) (439 ) (529 ) Net cash provided by (used for) financing activities (14,241 ) 254,980 (529 ) Net change in cash and cash equivalents (20,667 ) 92,484 (573 ) Cash and cash equivalents at beginning of year 121,632 29,148 29,721 Cash and cash equivalents at end of year $ 100,965 $ 121,632 $ 29,148

Selected Quarterly Financial 45

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	First Quarter Second Quarter Third Quarter Fourth Quarter 2015 2014 2015 2014 2015 2014 2015 2014 (In thousands, except share data) Interest and dividend income $ 12,682 $ 10,169 $ 13,130 $ 11,551 $ 15,418 $ 13,070 $ 17,071 $ 14,485 Interest expense 2,017 1,655 2,015 1,674 2,213 1,651 2,499 1,918 Net interest and dividend income 10,665 8,514 11,115 9,877 13,205 11,419 14,572 12,567 Provision for loan losses 279 714 544 959 1,318 1,438 1,949 270 Other noninterest income 866 1,088 2,210 1,119 1,456 3,025 2,179 1,860 Realized securities gains and impairment losses, net 1,318 541 267 1,191 238 349 145 434 Total noninterest income 2,184 1,629 2,477 2,310 1,694 3,374 2,324 2,294 Total noninterest expense 10,626 10,256 10,660 10,662 10,848 17,748 11,948 10,742 Provision (benefit) for income taxes 638 (428 ) 689 137 923 (1,435 ) 587 1,104 Net income (loss) $ 1,306 $ (399 ) $ 1,699 $ 429 $ 1,810 $ (2,958 ) $ 2,412 $ 2,745 Basic earnings per share $ 0.05 n/a $ 0.06 n/a $ 0.07 n/a $ 0.09 $ 0.10 Diluted earnings per share $ 0.05 n/a $ 0.06 n/a $ 0.07 n/a $ 0.09 $ 0.10 Weighted average common shares (basic) 26,274,738 n/a 26,293,560 n/a 26,183,381 n/a 25,500,755 26,243,957 Weighted average common shares (diluted) 26,274,738 n/a 26,293,560 n/a 26,183,381 n/a 25,554,961 26,243,957

Basis of Presentation and Con46

Basis of Presentation and Consolidation (Details) - USD ($)	Jul. 21, 2014	Jul. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Subsidiary or Equity Method Investee [Line Items]
Issuance of common stock (in shares)	27,772,500
Shares issued (in dollars per share)	$ 10		$ 10
Net proceeds from issuance of common stock	$ 277,725,000		$ 0	$ 274,143,000	$ 0
Employee stock ownership plan, shares	2,277,345		2,277,345
Employee stock ownership plan, value	$ 22,773,450
Liquidation account amount			$ 80,700,000	135,700,000
Restricted cash and cash equivalents			$ 4,000,000	28,100,000
Core deposit intangible useful life			5 years 6 months
1-4 Family Residential
Subsidiary or Equity Method Investee [Line Items]
Origination covenants, maximum loan-to-value ratio (greater than)			80.00%
Other Assets
Subsidiary or Equity Method Investee [Line Items]
Non-marketable investments			$ 8,700,000	6,100,000
Blue Hills Bank Foundation
Subsidiary or Equity Method Investee [Line Items]
Issuance of common stock (in shares)	694,313
Capital contribution to affiliate	$ 7,000,000
Cash payment to affiliate		$ 57,000
Federal Home Loan Bank of Boston
Subsidiary or Equity Method Investee [Line Items]
Impairments of investments			$ 0	$ 0

Basis of Presentation and Con47

Basis of Presentation and Consolidation - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 4,232	$ 0
Acquisition of Nantucket Bank		6,040
Amortization	(1,607)	(1,808)	$ 0
Ending balance	$ 2,625	$ 4,232	$ 0

Basis of Presentation and Con48

Basis of Presentation and Consolidation - Estimated Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
2,016	$ 1,225
2,017	843
2,018	461
2,019	96
Total remaining	$ 2,625	$ 4,232	$ 0

Recent Accounting Standards U49

Recent Accounting Standards Update (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net loss	$ (2,412)	$ (1,810)	$ (1,699)	$ (1,306)	$ (2,745)	$ 2,958	$ (429)	$ 399	$ (7,227)	$ 183	$ (2,663)
New Accounting Pronouncement, Early Adoption, Effect | Pro Forma
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net loss									$ 3,700

Securities - Available-for-sale

Securities - Available-for-sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt securities:
Amortized Cost	$ 186,779	$ 370,010
Gross Unrealized Gains	1,155	3,943
Gross Unrealized Losses	(3,820)	(804)
Fair Value	184,114	373,149
Marketable equity securities:
Amortized Cost	50,612	41,172
Gross Unrealized Gains	461	2,207
Gross Unrealized Losses	(3,497)	(81)
Fair Value	47,576	43,298
Available-for-sale securities:
Amortized Cost	237,391	411,182
Gross Unrealized Gains	1,616	6,150
Gross Unrealized Losses	(7,317)	(885)
Fair Value	231,690	416,447
U.S. Treasury
Debt securities:
Amortized Cost		13,037
Gross Unrealized Gains		182
Gross Unrealized Losses		0
Fair Value		13,219
Government-sponsored enterprises
Debt securities:
Amortized Cost		26,335
Gross Unrealized Gains		131
Gross Unrealized Losses		(29)
Fair Value		26,437
Government-sponsored mortgage-backed and collateralized mortgage obligations
Debt securities:
Amortized Cost		160,091
Gross Unrealized Gains		756
Gross Unrealized Losses		(294)
Fair Value		160,553
Privately issued commercial mortgage- backed securities
Debt securities:
Amortized Cost	13,126	22,100
Gross Unrealized Gains	0	30
Gross Unrealized Losses	(195)	(201)
Fair Value	12,931	21,929
SBA asset-backed securities
Debt securities:
Amortized Cost		27,765
Gross Unrealized Gains		308
Gross Unrealized Losses		(27)
Fair Value		28,046
Other asset-backed securities
Debt securities:
Amortized Cost	11,395	16,235
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(142)	(43)
Fair Value	11,253	16,192
Total other mortgage- and asset-backed securities
Debt securities:
Amortized Cost	24,521	66,100
Gross Unrealized Gains	0	338
Gross Unrealized Losses	(337)	(271)
Fair Value	24,184	66,167
State and political
Debt securities:
Amortized Cost	16,016	15,619
Gross Unrealized Gains	354	567
Gross Unrealized Losses	(55)	(3)
Fair Value	16,315	16,183
Global
Marketable equity securities:
Amortized Cost	5,000	5,000
Gross Unrealized Gains	388	623
Gross Unrealized Losses	0	0
Fair Value	5,388	5,623
Domestic community
Marketable equity securities:
Amortized Cost	3,216	3,216
Gross Unrealized Gains	70	86
Gross Unrealized Losses	(13)	(5)
Fair Value	3,273	3,297
Global asset allocation
Marketable equity securities:
Amortized Cost	42,396	32,956
Gross Unrealized Gains	3	1,498
Gross Unrealized Losses	(3,484)	(76)
Fair Value	38,915	34,378
Financial Services | Corporate debt securities
Debt securities:
Amortized Cost	58,820	37,547
Gross Unrealized Gains	488	1,023
Gross Unrealized Losses	(545)	(33)
Fair Value	58,763	38,537
Banks | Corporate debt securities
Debt securities:
Amortized Cost	18,813	12,364
Gross Unrealized Gains	138	531
Gross Unrealized Losses	(90)	(6)
Fair Value	18,861	12,889
Diversified financial entities | Corporate debt securities
Debt securities:
Amortized Cost	23,124	15,796
Gross Unrealized Gains	349	354
Gross Unrealized Losses	(173)	(18)
Fair Value	23,300	16,132
Insurance and REITs | Corporate debt securities
Debt securities:
Amortized Cost	16,883	9,387
Gross Unrealized Gains	1	138
Gross Unrealized Losses	(282)	(9)
Fair Value	16,602	9,516
Other Corporate | Corporate debt securities
Debt securities:
Amortized Cost	87,422	51,281
Gross Unrealized Gains	313	946
Gross Unrealized Losses	(2,883)	(174)
Fair Value	84,852	52,053
Industrials | Corporate debt securities
Debt securities:
Amortized Cost	55,470	34,408
Gross Unrealized Gains	306	681
Gross Unrealized Losses	(1,244)	(54)
Fair Value	54,532	35,035
Utilities | Corporate debt securities
Debt securities:
Amortized Cost	31,952	16,873
Gross Unrealized Gains	7	265
Gross Unrealized Losses	(1,639)	(120)
Fair Value	$ 30,320	$ 17,018

Securities - Held-to-maturity S

Securities - Held-to-maturity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 200,141	$ 0
Gross Unrealized Gains	104
Gross Unrealized Losses	(1,019)
Fair Value	199,226
U.S. Treasury
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	636
Gross Unrealized Gains	0
Gross Unrealized Losses	(2)
Fair Value	634
Government-sponsored enterprises
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	28,256
Gross Unrealized Gains	94
Gross Unrealized Losses	(126)
Fair Value	28,224
Government-sponsored mortgage-backed and collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	155,232
Gross Unrealized Gains	10
Gross Unrealized Losses	(832)
Fair Value	154,410
SBA asset-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	16,017
Gross Unrealized Gains	0
Gross Unrealized Losses	(59)
Fair Value	$ 15,958

Securities - Schedule of Contra

Securities - Schedule of Contractual Maturities of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Within 1 year, Available-for-sale, Amortized Cost	$ 6,572
After 1 year through 5 years, Available-for-sale, Amortized Cost	85,860
After 5 years through 10 years, Available-for-sale, Amortized Cost	62,163
After 10 years, Available-for-sale, Amortized Cost	7,663
Single Maturity Date, Available-for-sale, Amortized Cost	162,258
Mortgage- and asset-backed securities and collateralized mortgage obligations amortizing monthly, Available-for-sale, Amortized Cost	24,521
Amortized Cost	186,779	$ 370,010
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Within 1 year, Available-for-sale, Fair Value	6,578
After 1 year through 5 years, Available-for-sale, Fair Value	85,640
After 5 years through 10 years, Available-for-sale, Fair Value	60,144
After 10 years, Available-for-sale, Fair Value	7,568
Single Maturity Date, Available-for-sale, Fair Value	159,930
Mortgage- and asset-backed securities and collateralized mortgage obligations amortizing monthly , Available-for-sale, Fair Value	24,184
Total debt securities, Available-for-sale, Fair Value	184,114	373,149
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis [Abstract]
Within 1 year, Held-to-maturity, Amortized Cost	5,667
After 1 year through 5 years, Held-to-maturity, Amortized Cost	14,202
After 5 years through 10 years, Held-to-maturity, Amortized Cost	9,023
After 10 years, Held-to-maturity, Amortized Cost	0
Single Maturity Date, Held-to-maturity, Amortized Cost	28,892
Mortgage- and asset-backed securities and collateralized mortgage obligations amortizing monthly, Held-to-maturity, Amortized Cost	171,249
Amortized Cost	200,141	$ 0
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value [Abstract]
Within 1 year, Held-to-maturity, Fair Value	5,667
After 1 year through 5 years, Held-to-maturity, Fair Value	14,109
After 5 years through 10 years, Held-to-maturity, Fair Value	9,082
After 10 years, Held-to-maturity, Fair Value	0
Single Maturity Date, Held-to-maturity, Fair Value	28,858
Mortgage- and asset-backed securities and collateralized mortgage obligations amortizing monthly, Held-to-maturity, Fair Value	170,368
Total debt securities, Held-to-maturity, Fair Value	$ 199,226

Securities - Available-for-sa53

Securities - Available-for-sale Securities Unrealized Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	$ (6,654)	$ (627)
Gross Unrealized Losses - More than twelve months	(663)	(258)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	169,507	171,067
Fair Value - More than twelve months	10,231	18,726
Total debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(3,170)	(551)
Gross Unrealized Losses - More than twelve months	(650)	(253)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	132,898	164,010
Fair Value - More than twelve months	9,778	18,264
Government-sponsored enterprises
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(12)
Gross Unrealized Losses - More than twelve months		(17)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		5,932
Fair Value - More than twelve months		1,080
Government-sponsored mortgage-backed and collateralized mortgage obligations
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(190)
Gross Unrealized Losses - More than twelve months		(104)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months		93,364
Fair Value - More than twelve months		8,425
Privately issued commercial mortgage- backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(84)	(69)
Gross Unrealized Losses - More than twelve months	(111)	(132)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	5,166	9,412
Fair Value - More than twelve months	7,765	8,759
SBA asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months		(27)
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		5,529
Fair Value - More than twelve months		0
Other asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(142)	(43)
Gross Unrealized Losses - More than twelve months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	11,253	16,192
Fair Value - More than twelve months	0	0
Total other mortgage- and asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(226)	(139)
Gross Unrealized Losses - More than twelve months	(111)	(132)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	16,419	31,133
Fair Value - More than twelve months	7,765	8,759
State and political
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(55)	$ (3)
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	3,324	$ 1,955
Fair Value - More than twelve months	0	0
Total marketable equity securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(3,484)	(76)
Gross Unrealized Losses - More than twelve months	(13)	(5)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	36,609	7,057
Fair Value - More than twelve months	453	462
Domestic community
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	0	0
Gross Unrealized Losses - More than twelve months	(13)	(5)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	0	0
Fair Value - More than twelve months	453	462
Global asset allocation
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(3,484)	(76)
Gross Unrealized Losses - More than twelve months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	36,609	7,057
Fair Value - More than twelve months	0	0
Financial Services | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(545)	(33)
Gross Unrealized Losses - More than twelve months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	43,954	14,760
Fair Value - More than twelve months	0	0
Banks | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(90)	(6)
Gross Unrealized Losses - More than twelve months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	14,070	2,907
Fair Value - More than twelve months	0	0
Diversified financial entities | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(173)	(18)
Gross Unrealized Losses - More than twelve months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	15,397	7,676
Fair Value - More than twelve months	0	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	(282)	(9)
Gross Unrealized Losses - More than twelve months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	14,487	4,177
Fair Value - More than twelve months	0	0
Other Corporate | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(2,344)	(174)
Gross Unrealized Losses - More than twelve months	(539)	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	69,201	16,866
Fair Value - More than twelve months	2,013	0
Industrials | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(957)	(54)
Gross Unrealized Losses - More than twelve months	(287)	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	43,848	9,575
Fair Value - More than twelve months	395	0
Utilities | Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(1,387)	(120)
Gross Unrealized Losses - More than twelve months	(252)	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Fair Value - Less than twelve months	25,353	7,291
Fair Value - More than twelve months	$ 1,618	$ 0

Securities - Held-to-maturity54

Securities - Held-to-maturity Securities Unrealized Loss (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	$ (1,019)
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	175,496
Fair Value - More than twelve months	0
U.S. Treasury
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(2)
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	634
Fair Value - More than twelve months	0
Government-sponsored enterprises
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(126)
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	14,084
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	(832)
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	144,820
Fair Value - More than twelve months	0
SBA asset-backed securities
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]
Gross Unrealized Losses - Less than twelve months	(59)
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	15,958
Fair Value - More than twelve months	$ 0

Securities - Narrative (Details

Securities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, transferred security, at carrying value	$ 196,300
Available-for sale securities, transferred security, unrealized gain (loss)	$ 666
Other comprehensive income (loss), held-to-maturity securities adjustment, before tax		$ 571	$ 0	$ 0
Proceeds for securities available for sale		99,522	362,941	314,947
AFS securities, gross realized gain		2,000	4,500	8,700
AFS securities, gross realized loss		$ 56	1,700	$ 3,600
Depreciation, percentage of amortized cost basis (less than)		2.00%
Gross unrealized losses		$ 3,497	81
U.S. Treasury and Government-Sponsored Enterprises
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale pledged as collateral, amortized cost		46,200	30,400
Securities available for sale pledged as collateral, at fair value		$ 46,000	$ 30,600
Mutual funds
Schedule of Available-for-sale Securities [Line Items]
Depreciation, percentage of amortized cost basis (less than)		9.00%
Gross unrealized losses		$ 3,500

Loans and The Allowance for L56

Loans and The Allowance for Loan Loss - Summary of Loan balances (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 1,539,176	$ 1,147,037
Allowance for loan losses	(17,102)	(12,973)
Discount and fair value adjustments on purchased loans	(1,959)	(2,970)
Deferred loan costs and fees, net	3,160	1,820
Loans, net	1,523,275	1,132,914
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,318,313	963,436
1-4 Family Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	599,938	460,273
Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	77,399	61,750
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	561,203	387,807
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	79,773	53,606
Commercial Business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	182,677	151,823
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 38,186	$ 31,778

Loans and The Allowance for L57

Loans and The Allowance for Loan Loss - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 39.8	$ 56.3	$ 47.6
Transferor's continuing involvement, arrangements of financial support, amount	1.2
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 30.6	$ 21.9

Loans and The Allowance for L58

Loans and The Allowance for Loan Loss - Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	$ 12,973	$ 9,671	$ 5,550
Provision (credit) for loan losses	4,090	3,381	4,094
Loans charged-off	(43)	(79)	(209)
Recoveries	82	0	236
Allowance for Credit Losses, ending balance	17,102	12,973	9,671
1-4 Family Residential
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	3,222	2,835	2,725
Provision (credit) for loan losses	612	405	39
Loans charged-off	0	(18)	(165)
Recoveries	82	0	236
Allowance for Credit Losses, ending balance	3,916	3,222	2,835
Home Equity
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	340	247	316
Provision (credit) for loan losses	296	93	(69)
Loans charged-off	0	0	0
Recoveries	0	0	0
Allowance for Credit Losses, ending balance	636	340	247
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	3,551	2,608	1,343
Provision (credit) for loan losses	3,596	943	1,265
Loans charged-off	0	0	0
Recoveries	0	0	0
Allowance for Credit Losses, ending balance	7,147	3,551	2,608
Construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	1,056	303	106
Provision (credit) for loan losses	308	753	197
Loans charged-off	0	0	0
Recoveries	0	0	0
Allowance for Credit Losses, ending balance	1,364	1,056	303
Commercial Business
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	3,410	2,416	565
Provision (credit) for loan losses	(571)	994	1,851
Loans charged-off	0	0	0
Recoveries	0	0	0
Allowance for Credit Losses, ending balance	2,839	3,410	2,416
Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	736	574	313
Provision (credit) for loan losses	79	223	305
Loans charged-off	(43)	(61)	(44)
Recoveries	0	0	0
Allowance for Credit Losses, ending balance	772	736	574
Unallocated
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for Credit Losses, beginning balance	658	688	182
Provision (credit) for loan losses	(230)	(30)	506
Loans charged-off	0	0	0
Recoveries	0	0	0
Allowance for Credit Losses, ending balance	$ 428	$ 658	$ 688

Loans and The Allowance for L59

Loans and The Allowance for Loan Loss - Additional Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	$ 404	$ 0
Allowance related to non-impaired loans	16,698	12,973
Total allowance for loan losses	17,102	12,973	$ 9,671	$ 5,550
Impaired loans	11,170	5,024
Non-impaired loans	1,528,006	1,142,013
Total loans	1,539,176	1,147,037
1-4 Family Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0	0
Allowance related to non-impaired loans	3,916	3,222
Total allowance for loan losses	3,916	3,222	2,835	2,725
Impaired loans	6,114	4,419
Non-impaired loans	593,824	455,854
Total loans	599,938	460,273
Home Equity
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0	0
Allowance related to non-impaired loans	636	340
Total allowance for loan losses	636	340	247	316
Impaired loans	270	578
Non-impaired loans	77,129	61,172
Total loans	77,399	61,750
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	384	0
Allowance related to non-impaired loans	6,763	3,551
Total allowance for loan losses	7,147	3,551	2,608	1,343
Impaired loans	4,631	0
Non-impaired loans	556,572	387,807
Total loans	561,203	387,807
Construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0	0
Allowance related to non-impaired loans	1,364	1,056
Total allowance for loan losses	1,364	1,056	303	106
Impaired loans	0	0
Non-impaired loans	79,773	53,606
Total loans	79,773	53,606
Commercial Business
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	10	0
Allowance related to non-impaired loans	2,829	3,410
Total allowance for loan losses	2,839	3,410	2,416	565
Impaired loans	10	0
Non-impaired loans	182,667	151,823
Total loans	182,677	151,823
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	10	0
Allowance related to non-impaired loans	762	736
Total allowance for loan losses	772	736	574	313
Impaired loans	145	27
Non-impaired loans	38,041	31,751
Total loans	38,186	31,778
Unallocated
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to impaired loans	0	0
Allowance related to non-impaired loans	428	658
Total allowance for loan losses	428	658	$ 688	$ 182
Impaired loans	0	0
Non-impaired loans	0	0
Total loans	$ 0	$ 0

Loans and The Allowance for L60

Loans and The Allowance for Loan Loss - Summary of Past Due and Non-accrual loans, by class (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 5,978	$ 6,406
Loans on Non-accrual	10,744	4,481
1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,277	5,029
Loans on Non-accrual	5,688	3,876
Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,226	1,155
Loans on Non-accrual	270	578
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,249
Loans on Non-accrual	4,631
Commercial Business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	23
Loans on Non-accrual	10
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	203	222
Loans on Non-accrual	145	27
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,344	4,034
30-59 Days Past Due | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,287	3,137
30-59 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,031	680
30-59 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
30-59 Days Past Due | Commercial Business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	23
30-59 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3	217
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,348	522
60-89 Days Past Due | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	522
60-89 Days Past Due | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	19	0
60-89 Days Past Due | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,249
60-89 Days Past Due | Commercial Business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
60-89 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	80	0
Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,286	1,850
Past Due 90 Days or More | 1-4 Family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	990	1,370
Past Due 90 Days or More | Home Equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	176	475
Past Due 90 Days or More | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Past Due 90 Days or More | Commercial Business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0
Past Due 90 Days or More | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 120	$ 5

Loans and The Allowance for L61

Loans and The Allowance for Loan Loss - Summary of Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Recorded Investment
Recorded Investment, without a valuation allowance	$ 6,419	$ 5,024
Recorded investment, with valuation allowance	4,751
Recorded investment, total	11,170
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	7,288	6,040
Unpaid Principal Balance, with a valuation allowance	4,752
Unpaid Principal Balance, total	12,040
Related Allowance	404	0
1-4 Family Residential
Recorded Investment
Recorded Investment, without a valuation allowance	6,114	4,419
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	6,824	5,211
Related Allowance		0
Home Equity
Recorded Investment
Recorded Investment, without a valuation allowance	270	578
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	425	804
Related Allowance		0
Commercial Real Estate
Recorded Investment
Recorded investment, with valuation allowance	4,631
Unpaid Principal Balance
Unpaid Principal Balance, with a valuation allowance	4,631
Related Allowance	384
Commercial Business
Recorded Investment
Recorded investment, with valuation allowance	10
Unpaid Principal Balance
Unpaid Principal Balance, with a valuation allowance	11
Related Allowance	10
Consumer
Recorded Investment
Recorded Investment, without a valuation allowance	35	27
Recorded investment, with valuation allowance	110
Unpaid Principal Balance
Unpaid Principal Balance, without a valuation allowance	39	25
Unpaid Principal Balance, with a valuation allowance	110
Related Allowance	$ 10	$ 0

Loans and The Allowance for L62

Loans and The Allowance for Loan Loss - Summary of Average Recorded Investments and Interest Income of Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Average Recorded Investment, without a valuation allowance		$ 4,586	$ 2,618
Interest Income Recognized, without a valuation allowance		232	61
Average Recorded Investment, with a valuation allowance	$ 6,450
Interest Income Recognized, with a valuation allowance	452
1-4 Family Residential
Financing Receivable, Impaired [Line Items]
Average Recorded Investment, without a valuation allowance	4,869	4,076	2,586
Interest Income Recognized, without a valuation allowance	270	213	61
Home Equity
Financing Receivable, Impaired [Line Items]
Average Recorded Investment, without a valuation allowance	575	476	32
Interest Income Recognized, without a valuation allowance	14	17	$ 0
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Average Recorded Investment, with a valuation allowance	926
Interest Income Recognized, with a valuation allowance	161
Commercial Business
Financing Receivable, Impaired [Line Items]
Average Recorded Investment, with a valuation allowance	2
Interest Income Recognized, with a valuation allowance	1
Consumer
Financing Receivable, Impaired [Line Items]
Average Recorded Investment, without a valuation allowance	34	34
Interest Income Recognized, without a valuation allowance	4	$ 2
Average Recorded Investment, with a valuation allowance	44
Interest Income Recognized, with a valuation allowance	$ 2

Loans and The Allowance for L63

Loans and The Allowance for Loan Loss - Troubled Debt Restructurings (Details) - 1-4 Family Residential $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)contract	Dec. 31, 2014USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	1
Pre-Modification Outstanding Recorded Investment	$ 728	$ 181
Post-Modification Outstanding Recorded Investment	$ 750	$ 193

Loans and The Allowance for L64

Loans and The Allowance for Loan Loss - Summary of Loan by Risk Rating (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1,539,176	$ 1,147,037
1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	599,938	460,273
Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	77,399	61,750
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	561,203	387,807
Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	79,773	53,606
Commercial Business
Financing Receivable, Recorded Investment [Line Items]
Total loans	182,677	151,823
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	38,186	31,778
Loans rated 1 - 6
Financing Receivable, Recorded Investment [Line Items]
Total loans	812,346	596,076
Loans rated 1 - 6 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,950	3,381
Loans rated 1 - 6 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	465	473
Loans rated 1 - 6 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	548,360	387,651
Loans rated 1 - 6 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	79,773	53,606
Loans rated 1 - 6 | Commercial Business
Financing Receivable, Recorded Investment [Line Items]
Total loans	181,792	150,960
Loans rated 1 - 6 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	6	5
Loans rated 7
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,421	4,966
Loans rated 7 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,461	3,095
Loans rated 7 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	321	852
Loans rated 7 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,765	156
Loans rated 7 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 7 | Commercial Business
Financing Receivable, Recorded Investment [Line Items]
Total loans	874	863
Loans rated 7 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 8
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,963	1,362
Loans rated 8 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,592	1,331
Loans rated 8 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	144	0
Loans rated 8 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,078	0
Loans rated 8 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 8 | Commercial Business
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 8 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	149	31
Loans rated 9
Financing Receivable, Recorded Investment [Line Items]
Total loans	712	709
Loans rated 9 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	701	709
Loans rated 9 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 9 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 9 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 9 | Commercial Business
Financing Receivable, Recorded Investment [Line Items]
Total loans	11	0
Loans rated 9 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 10
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 10 | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 10 | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 10 | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 10 | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 10 | Commercial Business
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans rated 10 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans not rated
Financing Receivable, Recorded Investment [Line Items]
Total loans	705,734	543,924
Loans not rated | 1-4 Family Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	591,234	451,757
Loans not rated | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Total loans	76,469	60,425
Loans not rated | Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans not rated | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans not rated | Commercial Business
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Loans not rated | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 38,031	$ 31,742

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 29,895	$ 26,844
Less accumulated depreciation and amortization	(9,880)	(8,056)
Property, plant and equipment, net	20,015	18,788
Depreciation and amortization of premises and equipment	1,800	1,500	$ 1,400
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,087	4,087
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 10,322	10,293
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	40 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 7,727	6,109
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	10 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 2,601	2,014
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Technology equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 5,088	4,266
Technology equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Technology equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 70	$ 75

Deposits - Summary of Deposit B

Deposits - Summary of Deposit Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Banking and Thrift [Abstract]
NOW and demand	$ 288,143	$ 245,117
Regular savings	287,344	303,834
Money market	368,050	280,139
Brokered money market	41,807	23,166
Total non-certificate accounts	985,344	852,256
Term certificates of $250,000 or more	65,364	56,325
Term certificates less than $250,000	246,614	245,430
Brokered certificates of deposit	136,527	58,705
Total certificate accounts	448,505	360,460
Total deposits	$ 1,433,849	$ 1,212,716

Deposits - Schedule of Contract

Deposits - Schedule of Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Time Deposits, Fiscal Year Maturity [Abstract]
Amount - 2016	$ 239,134
Amount - 2017	86,464
Amount - 2018	40,570
Amount - 2019	44,630
Amount - 2020	37,707
Total certificate accounts	$ 448,505	$ 360,460
Weighted Average Rate of Time Deposits [Abstract]
Weighted Average Rate - 2016	0.62%
Weighted Average Rate - 2017	1.10%
Weighted Average Rate - 2018	1.37%
Weighted Average Rate - 2019	1.90%
Weighted Average Rate - 2020	1.92%
Weighted Average Rate	1.01%

Borrowings - FHLB Advances Fisc

Borrowings - FHLB Advances Fiscal Year Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
2,016	$ 10,000	$ 10,000
2,017	15,000	15,000
2,018	20,000	10,000
2,020	10,000	0
Total FHLB advances	$ 55,000	$ 35,000
Federal Home Loan Bank, Advances, Maturities Summary, Average Interest Rate of Amounts Due [Abstract]
2,016	2.29%	2.29%
2,017	1.99%	1.99%
2,018	2.23%	3.16%
2,020	1.65%	0.00%
Weighted average rate	2.07%	2.41%

Borrowings - Additional Informa

Borrowings - Additional Information (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Federal Home Loan Bank of Boston
Debt Instrument [Line Items]
FFHLB advances with an original maturity of less than one year	$ 205,000,000	$ 40,000,000
Weighted average rate (percent)	0.41%	0.24%
Line of Credit | Federal Home Loan Bank of Boston
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 7,700,000	$ 7,700,000
Line of credit, amount outstanding	0
Unsecured Federal Funds Line of Credit | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	39,000,000	$ 32,000,000
Line of credit, amount outstanding	$ 0

Income Taxes - Provisions (Bene

Income Taxes - Provisions (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current tax provision:
Federal									$ 2,933	$ 2,695	$ 960
State									206	240	172
Current income tax provision									3,139	2,935	1,132
Deferred tax provision (benefit):
Federal									7	(3,183)	(1,609)
State									(148)	(1,014)	(502)
Federal and State									(141)	(4,197)	(2,111)
Change in valuation reserve									(161)	640	695
Deferred income tax benefit									(302)	(3,557)	(1,416)
Provision (benefit) for income taxes	$ 587	$ 923	$ 689	$ 638	$ 1,104	$ (1,435)	$ 137	$ (428)	$ 2,837	$ (622)	$ (284)

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal statutory rate									34.00%	34.00%	34.00%
Statutory federal tax provision (benefit) at 34%									$ 3,429	$ (274)	$ 809
Increase (decrease) resulting from:
State taxes, net of federal tax benefit									39	(511)	(218)
Dividends received deduction									(211)	(201)	(134)
Tax-exempt bank-owned life insurance									(351)	(404)	(984)
Tax-exempt interest									(222)	(277)	(224)
Change in valuation reserve									(161)	640	695
Nondeductible IPO costs									0	202	0
Other, net									314	203	(228)
Provision (benefit) for income taxes	$ 587	$ 923	$ 689	$ 638	$ 1,104	$ (1,435)	$ 137	$ (428)	$ 2,837	$ (622)	$ (284)
Effective tax rates									28.20%	77.30%	(11.90%)

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Examination [Line Items]
Deferred tax assets, gross	$ 15,279	$ 10,996
Valuation reserve	(1,966)	(2,012)
Deferred tax assets, net	13,313	8,984
Deferred tax liabilities, gross	(2,648)	(2,751)
Net deferred tax asset	10,665	6,233	$ 2,831	$ (3,165)
Federal
Income Tax Examination [Line Items]
Deferred tax assets, gross	12,091	8,453
Deferred tax liabilities, gross	(2,138)	(2,429)
State
Income Tax Examination [Line Items]
Deferred tax assets, gross	3,188	2,543
Deferred tax liabilities, gross	$ (510)	$ (322)

Income Taxes - Tax Effect on De

Income Taxes - Tax Effect on Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Depreciation and amortization	$ 929	$ 603
Employee benefit plans and share-based compensation plans	901	682
Allowance for loan losses	6,831	5,181
Contribution carryover	2,675	3,281
Net unrealized loss on securities held as, or transferred from, available for sale	1,748	0
Net unrealized losses on defined benefit pension plan	1,052	543
Other	159	71
Valuation reserve	(1,966)	(2,012)
Deferred tax liabilities:
Deferred loan origination costs	(1,664)	(243)
Net unrealized gain on securities available for sale	0	(1,873)
Net deferred tax asset	$ 10,665	$ 6,233	$ 2,831	$ (3,165)

Income Taxes - Changes in Defer

Income Taxes - Changes in Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) In Deferred Taxes [Roll Forward]
Balance at beginning of year	$ 6,233	$ 2,831	$ (3,165)
Deferred tax benefit	302	3,557	1,416
Tax effect of changes in accumulated other comprehensive income	4,130	(155)	4,580
Balance at end of year	$ 10,665	$ 6,233	$ 2,831

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Examination [Line Items]
Deferred tax assets, valuation allowance	$ 1,966,000	$ 2,012,000
Carryforward period (years)	5 years
Bad debt reserve for tax purposes of qualified lender, percentage of reserve subject taxation	150.00%
Income taxes, penalties and interest expense	$ 0	$ 0	$ 0
Federal
Income Tax Examination [Line Items]
Bad debt reserve for tax purposes of qualified lender	1,300,000
Deferred income tax liability not recognized	$ 503,000

Income Taxes - Change in Valuat

Income Taxes - Change in Valuation Allowance (Details) - Valuation Allowance of Deferred Tax Assets $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ (2,012)
Change through the income statement	161
Change through other comprehensive income	(115)
Balance at end of year	(1,966)
Federal
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	(544)
Change through the income statement	344
Change through other comprehensive income	0
Balance at end of year	(200)
State
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	(1,468)
Change through the income statement	(183)
Change through other comprehensive income	(115)
Balance at end of year	$ (1,766)

Equity - Additional Information

Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 11, 2014	Dec. 31, 2015	Jan. 01, 2015	Dec. 31, 2014	Sep. 22, 2011
Class of Stock [Line Items]
Tier 1 capital to risk-weighted assets ratio (percent)			4.50%
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets (percent)		6.00%	6.00%	4.00%
Minimum Capital Requirement - Tier 1 Capital to Average Assets (percent)		4.00%	4.00%	4.00%
Tier 1 capital conservation buffer common equity to RWA (percent) (greater than)			2.50%
Tier 1 capital conservation buffer common equity capital to RWA, phasing period (years)		3 years
Preferred stock, shares issued		0		0	18,724
Liquidation value					$ 1,000
Preferred stock		$ 0		$ 0	$ 18,700
Preferred stock, redemption amount	$ 18,700
Payments for repurchase of redeemable preferred stock	$ 18,700
Preferred stock, shares authorized		50,000,000		50,000,000
Preferred stock, par value (dollars per share)		$ 0		$ 0
Preferred stock, shares outstanding		0		0
Retained earnings, unappropriated		$ 157,900
Funds available for loans or advances from the Bank		$ 29,100
Blue Hills Bank
Class of Stock [Line Items]
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets (percent)		6.00%		4.00%
Minimum Capital Requirement - Tier 1 Capital to Average Assets (percent)		4.00%		4.00%
Equity restrictions		$ 130,800

Equity - Minimum Required Capit

Equity - Minimum Required Capital (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jan. 01, 2015	Dec. 31, 2014
Total capital (to risk weighted assets)
Actual - Total Capital to Risk Weighted Assets	$ 407,444		$ 409,545
Actual - Total Capital to Risk Weighted Assets (percent)	24.80%		32.60%
Minimum Capital Requirement - Total Capital to Risk Weighted Assets	$ 131,231		$ 100,513
Minimum Capital Requirement - Total Capital to Risk Weighted Assets (percent)	8.00%		8.00%
Minimum to Be Well Capitalized - Total Capital to Risk Weighted Assets	$ 164,039
Minimum to Be Well Capitalized - Total Capital to Risk Weighted Assets (percent)	10.00%
Tier 1 capital (to risk weighted assets)
Actual - Tier 1 Capital to Risk Weighted Assets	$ 390,342		$ 395,615
Actual - Tier 1 Capital to Risk Weighted Assets (percent)	23.80%		31.50%
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets	$ 98,423		$ 50,257
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets (percent)	6.00%	6.00%	4.00%
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets	$ 131,231
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets (percent)	8.00%
Common equity Tier 1(to risk weighted assets)
Actual - Common Equity to Risk Weighted Assets	$ 390,342
Actual - Common Equity to Risk Weighted Assets (percent)	23.80%
Minimum Capital Requirement - Common Equity to Risk Weighted Assets	$ 73,818
Minimum Capital Requirement - Common Equity to Risk Weighted Assets (percent)	4.50%
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets	$ 106,625
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets (percent)	6.50%
Tier 1 capital (to average assets)
Actual - Tier 1 Capital to Average Assets	$ 390,342		$ 395,615
Actual - Tier 1 Capital to Average Assets (percent)	19.60%		23.30%
Minimum Capital Requirement - Tier 1 Capital to Average Assets	$ 79,658		$ 67,820
Minimum Capital Requirement - Tier 1 Capital to Average Assets (percent)	4.00%	4.00%	4.00%
Minimum To Be Well Capitalized - Tier 1 Capital to Average Assets	$ 99,573
Minimum To Be Well Capitalized - Tier 1 Capital to Average Assets (percent)	5.00%
Blue Hills Bank
Total capital (to risk weighted assets)
Actual - Total Capital to Risk Weighted Assets	$ 296,309		$ 283,443
Actual - Total Capital to Risk Weighted Assets (percent)	18.10%		22.70%
Minimum Capital Requirement - Total Capital to Risk Weighted Assets	$ 130,832		$ 99,973
Minimum Capital Requirement - Total Capital to Risk Weighted Assets (percent)	8.00%		8.00%
Minimum to Be Well Capitalized - Total Capital to Risk Weighted Assets	$ 163,540		$ 124,966
Minimum to Be Well Capitalized - Total Capital to Risk Weighted Assets (percent)	10.00%		10.00%
Tier 1 capital (to risk weighted assets)
Actual - Tier 1 Capital to Risk Weighted Assets	$ 279,207		$ 269,513
Actual - Tier 1 Capital to Risk Weighted Assets (percent)	17.10%		21.60%
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets	$ 98,124		$ 49,987
Minimum Capital Requirement - Tier 1 Capital to Risk Weighted Assets (percent)	6.00%		4.00%
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets	$ 130,832		$ 74,980
Minimum to Be Well Capitalized - Tier 1 Capital to Risk Weighted Assets (percent)	8.00%		6.00%
Common equity Tier 1(to risk weighted assets)
Actual - Common Equity to Risk Weighted Assets	$ 279,207
Actual - Common Equity to Risk Weighted Assets (percent)	17.10%
Minimum Capital Requirement - Common Equity to Risk Weighted Assets	$ 73,593
Minimum Capital Requirement - Common Equity to Risk Weighted Assets (percent)	4.50%
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets	$ 106,301
Minimum to Be Well Capitalized - Common Equity to Risk Weighted Assets (percent)	6.50%
Tier 1 capital (to average assets)
Actual - Tier 1 Capital to Average Assets	$ 279,207		$ 269,513
Actual - Tier 1 Capital to Average Assets (percent)	14.00%		15.90%
Minimum Capital Requirement - Tier 1 Capital to Average Assets	$ 79,867		$ 67,707
Minimum Capital Requirement - Tier 1 Capital to Average Assets (percent)	4.00%		4.00%
Minimum To Be Well Capitalized - Tier 1 Capital to Average Assets	$ 99,608		$ 84,634
Minimum To Be Well Capitalized - Tier 1 Capital to Average Assets (percent)	5.00%		5.00%

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2015	Jul. 21, 2014	Dec. 15, 2013	Feb. 29, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
401(k) Plan, minimum service period required to be a participant (months)						3 months
401(k) Employer non-elective contribution based on earnings (percent)			3.00%
401(k) Employer elective contribution based on earnings (percent)			2.00%
401(k) plan expense	4.00%					3.00%
401(k) Employer matching contribution, percent match, first 3%	100.00%
401(k) Employer matching contribution, percent match, remaining 2%	50.00%
401(k) Employer matching contribution (percent)					$ 610	$ 465
Short-term Incentive Compensation expense					$ 2,300	3,000	$ 1,600
Employee stock ownership plan, shares		2,277,345			2,277,345
Shares issued (in dollars per share)		$ 10			$ 10
ESOP, term of loan (years)					30 years
ESOP, interest rate (percent)					3.25%
ESOP, number of annual committed-to-be-released shares					75,912
ESOP, number of suspense shares fair value					$ 32,500	29,900
ESOP expense					$ 1,063	993	0
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, minimum required age					21 years
Defined benefit plan, minimum hours of service required					1000 hours
Defined benefit plan, required period to perform service (years)					12 months
Net periodic pension cost (benefit)					$ (234)	(1,218)	400
SERP
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, required period to perform service (years)					5 years
Net periodic pension cost (benefit)							$ 873
Shares paid for tax withholdings for share based compensation					27,956
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocation, minimum (percent)					40.00%
Target plan asset allocation, maximum (percent)					64.00%
Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocation, minimum (percent)					15.00%
Target plan asset allocation, maximum (percent)					25.00%
Other Investments
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocation, minimum (percent)					20.00%
Target plan asset allocation, maximum (percent)					36.00%
Parent Company
Defined Benefit Plan Disclosure [Line Items]
ESOP, loan balance					$ 21,459	$ 21,925
Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Employer contribution				$ 470

Employee Benefit Plans - Accumu

Employee Benefit Plans - Accumulated Benefit Obligations (Details) - Pension Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in plan assets:
Fair value of plan assets at beginning of year	$ 9,443	$ 9,535	$ 9,331
Actual return (loss) on plan assets	(304)	391	1,513
Benefits paid	(325)	(483)	(1,309)
Fair value of plan assets at end of year	8,814	9,443	9,535
Change in benefit obligation:
Benefit obligation at beginning of year	10,135	9,287	10,818
Service cost	0	484	708
Interest cost	401	407	423
Actuarial loss (gain)	561	2,230	(1,353)
Benefits paid	(325)	(483)	(1,309)
Curtailment gain	0	(1,790)	0
Benefit obligation at end of year	10,772	10,135	9,287
Funded status and prepaid expense (accrued liability) at end of year	(1,958)	(692)	248
Accumulated benefit obligation at end of year	$ 10,772	$ 10,135	$ 7,507

Employee Benefit Plans - Benefi

Employee Benefit Plans - Benefit Obligation Assumptions Used (Details)	Dec. 31, 2015	Dec. 31, 2014
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.01%	4.00%

Employee Benefit Plans - Net Pe

Employee Benefit Plans - Net Periodic Pension Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Curtailment gain	$ 0	$ (1,304)	$ 0
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	484	708
Interest cost	401	407	423
Expected return on plan assets	(745)	(735)	(728)
Amortization of net actuarial loss (gain)	110	(70)	104
Settlement gain	0	0	(107)
Curtailment gain	0	(1,304)	0
Net periodic pension cost (benefit)	$ (234)	$ (1,218)	$ 400

Employee Benefit Plans - Net 83

Employee Benefit Plans - Net Periodic Pension Costs Assumptions Used (Details) - Pension Plan	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.00%	4.25%	4.00%
Expected long-term rate of return on plan assets	8.00%	8.00%	8.00%
Rate of compensation increase			3.00%

Employee Benefit Plans - Fair V

Employee Benefit Plans - Fair Value of Pension Plan Assets (Details) - Pension Plan - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	$ 8,814	$ 9,443	$ 9,535	$ 9,331
Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	3,888	4,374
Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	4,266	4,410
Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	660	659
Collective funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	5,392	5,046
Collective funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	1,126	770
Collective funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	4,266	4,276
Collective funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	0
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	1,566	2,178
Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	1,566	2,178
Equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	0
Equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	0
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	1,046	1,464
Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	1,046	1,330
Mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	134
Mutual funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	0
Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	660	659
Hedge funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	0
Hedge funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	0
Hedge funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	660	659
Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	150	96
Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	150	96
Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	0	0
Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	$ 0	$ 0

Employee Benefit Plans - Expect

Employee Benefit Plans - Expected Benefit Payments (Details) $ in Thousands	Dec. 31, 2015USD ($)
Compensation and Retirement Disclosure [Abstract]
2,016	$ 495
2,017	679
2,018	934
2,019	543
2,020	655
2021-2025	$ 3,239

Employee Benefit Plans - Employ

Employee Benefit Plans - Employee Stock Ownership Plan (Details) - shares	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Allocated	75,912	0
Committed to be allocated	75,912	75,912
Unallocated	2,124,846	2,201,433
Total	2,276,670	2,277,345

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	2,846,681
Expected life (years)	6 years 6 months
Vesting period (years)	5 years
Share-based compensation expense	$ 473,000	$ 0	$ 0
Tax benefit related to share-based compensation expense	$ 112,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,138,673
Share-based compensation expense	$ 651,000	$ 0	$ 0
Tax benefit related to share-based compensation expense	$ 228,000
Granted (shares)	983,175
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	40,000
Maximum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (years)	10 years

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (shares)	2,434,000	0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (shares)	2,434,000
Vesting period (years)	5 years
Expected volatility (percent)	28.85%
Expected life (years)	6 years 6 months
Expected dividend yield (percent)	0.54%
Risk free interest rate (percent)	1.55%
Fair value per option (dollars per share)	$ 4.23

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2015USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (shares)	0
Granted (shares)	2,434,000
Ending balance (shares)	2,434,000
Outstanding and expected to vest at end of period (shares)	2,434,000
Exercisable at end of period (shares)	0
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	$ 0
Granted, weighted average exercise price (dollars per share) | $ / shares	14.07
Ending balance, weighted average exercise price (dollars per share) | $ / shares	14.07
Outstanding and expected to vest at end of period, weighted average exercise price (dollars per share) | $ / shares	14.07
Exercisable at end of period, weighted average exercise price (dollars per share) | $ / shares	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Granted, weighted average remaining contractual term (years)	9 years 9 months 11 days
Outstanding, weighted average remaining contractual term (years)	9 years 9 months 11 days
Outstanding and expected to vest, weighted average remaining contractual term (years)	9 years 9 months 11 days
Granted, aggregate intrinsic value | $	$ 3,018,160
Outstanding, aggregate intrinsic value | $	3,018,160
Outstanding and expected to vest, aggregate intrinsic value | $	3,018,160
Exercisable, aggregate intrinsic value | $	$ 0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Ending balance (shares)	2,434,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Unrecognized compensation cost | $	$ 9,822,000
Weighted average remaining recognition period (years)	4 years 9 months 7 days

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Activity (Details) - Restricted Stock $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / 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	0
Granted (shares) | shares	983,175
Ending balance (shares) | shares	983,175
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	$ 0
Granted, weighted average exercise price (dollars per share) | $ / shares	14.07
Ending balance, weighted average exercise price (dollars per share) | $ / shares	$ 14.07
Unrecognized compensation cost inclusive of directors' fees | $	$ 13,182
Weighted average remaining recognition period (years)	4 years 9 months 7 days

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net income (loss)	$ 2,412	$ 1,810	$ 1,699	$ 1,306	$ 2,745	$ (2,958)	$ 429	$ (399)	$ 7,227	$ (183)	$ 2,663
Average number of common shares outstanding (shares)									28,228,425
Less: Average unallocated ESOP shares (shares)									(2,163,478)
Average number of common shares outstanding used to calculate basic earnings per common share (shares)	25,500,755	26,183,381	26,293,560	26,274,738	26,243,957				26,064,947
Effect of dilutive unvested restricted stock awards (shares)									4,642
Average number of common shares outstanding used to calculate diluted earnings per common share (shares)	25,554,961	26,183,381	26,293,560	26,274,738	26,243,957				26,069,589
Basic earnings per share (dollars per share)	$ 0.09	$ 0.07	$ 0.06	$ 0.05	$ 0.10				$ 0.28
Diluted earnings per share (dollars per share)	$ 0.09	$ 0.07	$ 0.06	$ 0.05	$ 0.10				$ 0.28
Antidilutive securities excluded from computation of earnings per share (shares)									2,434,000

Commitments and Contingencies -

Commitments and Contingencies - Credit Related Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Commitments to originate loans
Other Commitments [Line Items]
Financial instruments with off-balance-sheet risk	$ 69,554	$ 44,504
Letters of credit
Other Commitments [Line Items]
Financial instruments with off-balance-sheet risk	3,571	7,133
Undisbursed construction loans
Other Commitments [Line Items]
Financial instruments with off-balance-sheet risk	4,844	6,679
Commercial Business
Other Commitments [Line Items]
Financial instruments with off-balance-sheet risk	128,748	81,607
Home equity
Other Commitments [Line Items]
Financial instruments with off-balance-sheet risk	84,374	37,580
Consumer
Other Commitments [Line Items]
Financial instruments with off-balance-sheet risk	$ 16,033	$ 16,057

Commitments and Contingencies93

Commitments and Contingencies - Operating Lease Commitments (Details) $ in Thousands	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 1,801
2,017	1,859
2,018	1,839
2,019	1,595
2,020	1,499
Thereafter	8,879
Total future minimum payments due	$ 17,472

Commitments and Contingencies94

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	Jan. 01, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Commitments [Line Items]
Operating leases, rental expense		$ 1,600	$ 1,100	$ 966
Renewal term		30 years
Chief Executive Officer
Other Commitments [Line Items]
Employment agreement, initial term (in years)		3 years
Employment agreement, automatic extension period (in years)		1 year
President
Other Commitments [Line Items]
Employment agreement, initial term (in years)		3 years
Employment agreement, automatic extension period (in years)		1 year
Boston Waterfront Music Venue Naming Rights Agreement
Other Commitments [Line Items]
Contractual obligation, period	10 years
Other commitment contractual obligation	$ 390,000	$ 410	$ 390
Contractual obligation, annual increase (percentage)	5.00%

Interest Rate Swap Agreements95

Interest Rate Swap Agreements (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Asset, notional amount	$ 290,846	$ 211,586
Derivative Asset, fair value	7,962	5,454
Derivative Liability, notional amount	295,244	211,257
Derivative Liability, fair value	8,489	5,842
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Derivative Asset, notional amount	282,546	202,970
Derivative Asset, fair value	7,956	5,446
Derivative Liability, notional amount	282,546	202,970
Derivative Liability, fair value	8,411	5,759
Other Contract
Derivatives, Fair Value [Line Items]
Derivative Asset, notional amount	8,300	8,616
Derivative Asset, fair value	6	8
Derivative Liability, notional amount	12,698	8,287
Derivative Liability, fair value	$ 78	$ 83

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets
Debt securities	$ 184,114	$ 373,149
Marketable equity securities	47,576	43,298
Recurring
Assets
Debt securities	184,114	373,149
Marketable equity securities	47,576	43,298
Derivative assets	7,962	5,454
Total assets	239,652	421,901
Liabilities
Derivative liabilities	8,489	5,842
Recurring | Level 1
Assets
Debt securities	0	13,219
Marketable equity securities	47,576	43,298
Derivative assets	0	0
Total assets	47,576	56,517
Liabilities
Derivative liabilities	0	0
Recurring | Level 2
Assets
Debt securities	184,114	359,930
Marketable equity securities	0	0
Derivative assets	7,962	5,454
Total assets	192,076	365,384
Liabilities
Derivative liabilities	8,489	5,842
Recurring | Level 3
Assets
Debt securities	0	0
Marketable equity securities	0	0
Derivative assets	0	0
Total assets	0	0
Liabilities
Derivative liabilities	$ 0	$ 0

Fair Value Measurements - Ass97

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring - Level 3 $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)loan	Dec. 31, 2014USD ($)loan
Fair Value Inputs, Equity, Quantitative Information [Line Items]
Number of impaired loans | loan	3	1
Impaired financing receivable, fair value disclosure	$ 4,800	$ 120
Impaired financing receivable, loss recognized in earnings	$ 404	$ 18

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value, Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financial assets:
Securities available for sale	$ 231,690	$ 416,447
Securities held to maturity	200,141	0
Carrying Amount
Financial assets:
Cash and cash equivalents	33,298	60,146
Securities available for sale	231,690	416,447
Securities held to maturity	200,141
Federal Home Loan Bank stock	13,567	11,702
Loans and loans held for sale, net	1,536,152	1,147,505
Accrued interest receivable	5,344	4,433
Financial liabilities:
Deposits	1,433,849	1,212,716
Borrowings	260,000	75,000
Estimate of Fair Value Measurement
Financial assets:
Cash and cash equivalents	33,298	60,146
Securities available for sale	231,690	416,447
Securities held to maturity	199,226
Federal Home Loan Bank stock	13,567	11,702
Loans and loans held for sale, net	1,538,809	1,132,024
Accrued interest receivable	5,344	4,433
Financial liabilities:
Deposits	1,434,179	1,214,251
Borrowings	260,244	76,074
Level 1
Financial assets:
Cash and cash equivalents	33,298	60,146
Securities available for sale	47,576	56,517
Securities held to maturity	634
Federal Home Loan Bank stock	0	0
Loans and loans held for sale, net	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	0	0
Borrowings	0	0
Level 2
Financial assets:
Cash and cash equivalents	0	0
Securities available for sale	184,114	359,930
Securities held to maturity	198,592
Federal Home Loan Bank stock	0	0
Loans and loans held for sale, net	0	0
Accrued interest receivable	0	0
Financial liabilities:
Deposits	0	0
Borrowings	260,244	76,074
Level 3
Financial assets:
Cash and cash equivalents	0	0
Securities available for sale	0	0
Securities held to maturity	0
Federal Home Loan Bank stock	13,567	11,702
Loans and loans held for sale, net	1,538,809	1,132,024
Accrued interest receivable	5,344	4,433
Financial liabilities:
Deposits	1,434,179	1,214,251
Borrowings	0	0
Interest Rate Swap | Carrying Amount
Financial liabilities:
Derivative assets	7,962	5,454
Derivative liabilities	8,489	5,842
Interest Rate Swap | Estimate of Fair Value Measurement
Financial liabilities:
Derivative assets	7,962	5,454
Derivative liabilities	8,489	5,842
Interest Rate Swap | Level 1
Financial liabilities:
Derivative assets	0	0
Derivative liabilities	0	0
Interest Rate Swap | Level 2
Financial liabilities:
Derivative assets	7,962	5,454
Derivative liabilities	8,489	5,842
Interest Rate Swap | Level 3
Financial liabilities:
Derivative assets	0	0
Derivative liabilities	$ 0	$ 0

Other Comprehensive Income - Co

Other Comprehensive Income - Components of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net-of-tax amount	$ (5,188)	$ 2,577
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)	(2,858)	(1,358)
Tax effect	1,052	543
Net-of-tax amount	(1,806)	(815)
Available-for-sale Securities | Accumulated Net Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)	(5,701)	5,265
Tax effect	1,945	(1,873)
Net-of-tax amount	(3,756)	3,392	$ 1,983	$ 10,805
Held-to-maturity Securities | Accumulated Net Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)	571	0
Tax effect	(197)	0
Net-of-tax amount	$ 374	$ 0	$ 0	$ 0

Other Comprehensive Income - Ch

Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,577
Unrealized gains on securities reclassified as held to maturity	(666)	$ 0	$ 0
Tax effects	4,130	(155)	4,580
Other comprehensive income (loss)	(7,765)	112	(7,538)
Ending balance	(5,188)	2,577
Actuarial gain expected to be included in AOCI	271
Defined Benefit Pension Plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(815)	482	(802)
Other comprehensive income (loss) before reclassifications	(1,610)	(2,090)	2,033
Realized gains reclassified	0
Amortization of actuarial losses	110	(70)	104
Tax effects	509	863	(853)
Other comprehensive income (loss)	(991)	(1,297)	1,284
Ending balance	(1,806)	(815)	482
Accumulated Other Comprehensive Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	2,577	2,465	10,003
Other comprehensive income (loss) before reclassifications	(9,942)	2,852	(7,223)
Realized gains reclassified	(1,968)	(2,515)	(4,999)
Amortization of actuarial losses	110	(70)	104
Unrealized gains on securities reclassified as held to maturity	0
Amortization of amounts previously recorded upon transfer to held-to-maturity from available-for-sale	(95)
Tax effects	4,130	(155)	4,580
Other comprehensive income (loss)	(7,765)	112	(7,538)
Ending balance	(5,188)	2,577	2,465
Available-for-sale Securities | Accumulated Net Investment Gain (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	3,392	1,983	10,805
Other comprehensive income (loss) before reclassifications	(8,332)	4,942	(9,256)
Realized gains reclassified	(1,968)	(2,515)	(4,999)
Unrealized gains on securities reclassified as held to maturity	(666)
Amortization of amounts previously recorded upon transfer to held-to-maturity from available-for-sale	0
Tax effects	3,818	(1,018)	5,433
Other comprehensive income (loss)	(7,148)	1,409	(8,822)
Ending balance	(3,756)	3,392	1,983
Held-to-maturity Securities | Accumulated Net Investment Gain (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	0	0	0
Other comprehensive income (loss) before reclassifications	0	0	0
Realized gains reclassified	0	0	0
Unrealized gains on securities reclassified as held to maturity	666
Amortization of amounts previously recorded upon transfer to held-to-maturity from available-for-sale	(95)
Tax effects	(197)	0	0
Other comprehensive income (loss)	374	0	0
Ending balance	$ 374	$ 0	$ 0

Condensed Financial Statemen101

Condensed Financial Statements of Parent Company (Condensed Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets [Abstract]
Total cash and cash equivalents	$ 33,298	$ 60,146
Other assets	20,060	18,907
Assets	2,114,343	1,728,148
Liabilities and Equity [Abstract]
Accrued expenses	21,665	28,826
Stockholders' equity	398,829	411,606	$ 171,534	$ 176,938
Liabilities and Equity	2,114,343	1,728,148
Parent Company
Assets [Abstract]
Cash balances at Blue Hills Bank	100,965	121,632
Total cash and cash equivalents	100,965	121,632
Investment in subsidiaries	311,357	308,606
Other assets	7,993	3,561
Assets	420,315	433,799
Liabilities and Equity [Abstract]
Liability to ESOP	21,459	21,925
Accrued expenses	27	268
Stockholders' equity	398,829	411,606
Liabilities and Equity	$ 420,315	$ 433,799

Condensed Financial Statemen102

Condensed Financial Statements of Parent Company (Condensed Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, Captions [Line Items]
Total income	$ 17,071	$ 15,418	$ 13,130	$ 12,682	$ 14,485	$ 13,070	$ 11,551	$ 10,169	$ 58,301	$ 49,275	$ 33,092
Income (loss) before income taxes									10,064	(805)	2,379
Applicable income tax benefit	587	923	689	638	1,104	(1,435)	137	(428)	2,837	(622)	(284)
Net income (loss)	$ 2,412	$ 1,810	$ 1,699	$ 1,306	$ 2,745	$ (2,958)	$ 429	$ (399)	7,227	(183)	2,663
Parent Company
Condensed Income Statements, Captions [Line Items]
Total income									713	331	0
Operating expenses									1,860	9,432	0
Income (loss) before income taxes									(1,147)	(9,101)	0
Applicable income tax benefit									(1,112)	(3,277)	0
Loss before equity in income of subsidiaries									(35)	(5,824)	0
Equity in undistributed net income of subsidiaries									7,975	5,972	2,663
Net income (loss)									$ 7,940	$ 148	$ 2,663

Condensed Financial Statemen103

Condensed Financial Statements of Parent Company (Condensed Statement of Cash Flow) (Details) - USD ($) $ in Thousands	Jul. 21, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss)		$ 2,412	$ 1,810	$ 1,699	$ 1,306	$ 2,745	$ (2,958)	$ 429	$ (399)	$ 7,227	$ (183)	$ 2,663
Issuance of common stock to charitable foundation										0	6,943	0
Net change in other assets										(1,153)	(7,033)	(824)
Net change in other liabilities										(8,661)	14,220	3,966
Net cash provided by operating activities										6,555	16,124	16,309
Cash flows from investing activities:
Net cash used for investing activities										(424,944)	(111,393)	(207,205)
Cash flows from financing activities:
Net proceeds from issuance of common stock	$ 277,725									0	274,143	0
Redemption of SBLF preferred stock										0	(18,724)	0
Repurchase of common stock										(13,121)	0	0
Common and Preferred Stock dividends paid										0	(439)	(529)
Net cash provided by financing activities										391,541	115,099	157,393
Net change in cash and cash equivalents										(26,848)	19,830	(33,503)
Cash and cash equivalents at beginning of year					60,146				40,316	60,146	40,316	73,819
Cash and cash equivalents at end of year		33,298				60,146				33,298	60,146	40,316
Parent Company
Cash flows from operating activities:
Net income (loss)										7,940	148	2,663
Equity in undistributed net income of subsidiaries										(7,975)	(5,972)	(2,663)
Issuance of common stock to charitable foundation										0	6,943	0
Net change in other assets										(2,221)	(2,062)	(44)
Net change in other liabilities										(241)	267	0
Net cash provided by operating activities										(2,497)	(676)	(44)
Cash flows from investing activities:
Investment in Blue Hills Bank										(3,929)	(161,820)	0
Net cash used for investing activities										(3,929)	(161,820)	0
Cash flows from financing activities:
Net proceeds from issuance of common stock										0	274,143	0
Redemption of SBLF preferred stock										0	(18,724)	0
Repurchase of common stock										(13,121)
Common and Preferred Stock dividends paid										(1,120)	(439)	(529)
Net cash provided by financing activities										(14,241)	254,980	(529)
Net change in cash and cash equivalents										(20,667)	92,484	(573)
Cash and cash equivalents at beginning of year					$ 121,632				$ 29,148	121,632	29,148	29,721
Cash and cash equivalents at end of year		$ 100,965				$ 121,632				$ 100,965	$ 121,632	$ 29,148

Selected Quarterly Financial104

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Interest and dividend income	$ 17,071	$ 15,418	$ 13,130	$ 12,682	$ 14,485	$ 13,070	$ 11,551	$ 10,169	$ 58,301	$ 49,275	$ 33,092
Interest expense	2,499	2,213	2,015	2,017	1,918	1,651	1,674	1,655	8,744	6,898	7,971
Net interest and dividend income	14,572	13,205	11,115	10,665	12,567	11,419	9,877	8,514	49,557	42,377	25,121
Provision for loan losses	1,949	1,318	544	279	270	1,438	959	714	4,090	3,381	4,094
Other noninterest income	2,179	1,456	2,210	866	1,860	3,025	1,119	1,088
Realized securities gains and impairment losses, net	145	238	267	1,318	434	349	1,191	541
Total noninterest income	2,324	1,694	2,477	2,184	2,294	3,374	2,310	1,629	8,679	9,607	13,011
Total noninterest expense	11,948	10,848	10,660	10,626	10,742	17,748	10,662	10,256	44,082	49,408	31,659
Provision (benefit) for income taxes	587	923	689	638	1,104	(1,435)	137	(428)	2,837	(622)	(284)
Net income (loss)	$ 2,412	$ 1,810	$ 1,699	$ 1,306	$ 2,745	$ (2,958)	$ 429	$ (399)	$ 7,227	$ (183)	$ 2,663
Basic earnings per share (dollars per share)	$ 0.09	$ 0.07	$ 0.06	$ 0.05	$ 0.10				$ 0.28
Diluted earnings per share (dollars per share)	$ 0.09	$ 0.07	$ 0.06	$ 0.05	$ 0.10				$ 0.28
Weighted average common shares (basic) (shares)	25,500,755	26,183,381	26,293,560	26,274,738	26,243,957				26,064,947
Weighted average common shares (diluted) (shares)	25,554,961	26,183,381	26,293,560	26,274,738	26,243,957				26,069,589