Randolph Bancorp (RNDB) 10-Q 8 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 08, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	RNDB
Entity Registrant Name	Randolph Bancorp, Inc.
Entity Central Index Key	1,667,161
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		5,868,544

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 4,073	$ 4,370
Interest-bearing deposits	4,770	10,479
Total cash and cash equivalents	8,843	14,849
Certificates of deposit	3,185	3,675
Securities available for sale, at fair value	67,144	68,637
Loans held for sale, at fair value	32,036	30,452
Loans, net of allowance for loan losses of $3,557 in 2017 and $3,271 in 2016	364,993	332,991
Federal Home Loan Bank stock, at cost	2,588	2,478
Accrued interest receivable	1,240	1,163
Mortgage servicing rights	8,992	8,486
Premises and equipment, net	7,051	6,280
Bank-owned life insurance	7,961	7,884
Other assets	3,906	4,329
Total assets	507,939	481,224
Deposits:
Non-interest bearing	69,834	59,646
Interest bearing	298,754	291,533
Total deposits	368,588	351,179
Federal Home Loan Bank advances	48,464	38,667
Mortgagors' escrow accounts	1,690	1,572
Post-employment benefit obligations	2,754	2,886
Other liabilities	3,104	3,618
Total liabilities	424,600	397,922
Commitments and contingencies (Note 13)
Stockholders' Equity:
Preferred stock, no par value; authorized: 1,000,000 shares; issued: none
Common stock, $.01 par value; authorized: 15,000,000 shares; 5,868,544 shares issued and outstanding at June 30, 2017 and 5,868,726 shares issued and outstanding at December 31, 2016	59	59
Additional paid-in capital	56,421	56,373
Retained earnings	32,064	32,661
ESOP-Unearned compensation	(4,413)	(4,507)
Accumulated other comprehensive loss, net of tax	(792)	(1,284)
Total stockholders' equity	83,339	83,302
Total liabilities and stockholders' equity	$ 507,939	$ 481,224

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Loans, allowance for loan losses	$ 3,557	$ 3,271
Preferred stock, par value
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	15,000,000	15,000,000
Common stock, shares issued	5,868,544	5,868,726
Common stock, shares outstanding	5,868,544	5,868,726

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest and dividend income:
Loans	$ 3,697	$ 2,830	$ 7,113	$ 5,548
Securities-taxable	368	307	726	625
Securities-tax exempt	88	91	177	187
Interest-bearing deposits and certificates of deposit	22	32	43	55
Total interest and dividend income	4,175	3,260	8,059	6,415
Interest expense:
Deposits	381	331	717	645
Federal Home Loan Bank advances	104	57	168	118
Total interest expense	485	388	885	763
Net interest income	3,690	2,872	7,174	5,652
Provision for loan losses	100		335	62
Net interest income after provision for loan losses	3,590	2,872	6,839	5,590
Non-interest income:
Customer service fees	378	396	750	753
Net gain on sales of mortgage loans	2,520	1,058	4,558	1,739
Mortgage servicing fees, net	290	69	950	169
Gain on sales/calls of securities				62
Increase in cash surrender value of life insurance	38	48	76	104
Gain on life insurance settlement		486		486
Other	208	29	510	75
Total non-interest income	3,434	2,086	6,844	3,388
Non-interest expenses:
Salaries and employee benefits	4,715	2,381	9,391	4,583
Occupancy and equipment	619	363	1,275	757
Data processing	179	131	361	386
Professional fees	369	305	671	591
Marketing	199	103	347	172
Foreclosed real estate, net		154		157
FDIC insurance	43	56	86	139
Merger and integration costs	357	33	524	150
Other	947	714	1,902	1,320
Total non-interest expenses	7,428	4,240	14,557	8,255
Income (loss) before income taxes	(404)	718	(874)	723
Income tax expense (benefit)	(254)		(277)	3
Net income (loss)	$ (150)	$ 718	$ (597)	$ 720
Weighted average common shares outstanding (basic and diluted)	5,425,033		5,422,694
Earnings (loss) per common share (basic and diluted)	$ (0.03)		$ (0.11)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income (loss)	$ (150)	$ 718	$ (597)	$ 720
Securities available for sale:
Unrealized holding gains	725	229	799	1,049
Reclassification adjustment for net gains realized in income	0	0	0	(62)
Net unrealized gains	725	229	799	987
Related tax effects	(254)	0	(280)	0
Net-of-tax amount	471	229	519	987
Related tax effects	0	0	0	0
Net-of-tax amount	(14)	2	(27)	5
Total other comprehensive income	457	231	492	992
Comprehensive income (loss)	307	949	(105)	1,712
Supplemental Retirement Plan [Member]
Securities available for sale:
Actuarial losses	9	9	18	18
Prior service credits recognized	(23)	(7)	(45)	(13)
Post-retirement benefit plans	$ (14)	$ 2	$ (27)	$ 5

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Unearned Compensation ESOP [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2015	$ 32,459			$ 32,198		$ 261
Net income (loss)	720			720
Other comprehensive income	992					992
Ending balance at Jun. 30, 2016	34,171			32,918		1,253
Beginning balance at Dec. 31, 2015	32,459			32,198		261
Ending balance at Dec. 31, 2016	83,302	$ 59	$ 56,373	32,661	$ (4,507)	(1,284)
Ending balance, shares at Dec. 31, 2016		5,868,726
Net income (loss)	(597)			(597)
Other comprehensive income	492					492
Repurchase of common stock	(3)		(3)
Repurchase of common stock, shares		(182)
ESOP shares committed to be released	145		51		94
Ending balance at Jun. 30, 2017	$ 83,339	$ 59	$ 56,421	$ 32,064	$ (4,413)	$ (792)
Ending balance, shares at Jun. 30, 2017		5,868,544

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ (597,000)	$ 720,000
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Provision for loan losses	335,000	62,000
Loans originated for sale	(201,423,000)	(60,888,000)
Principal balance of loans sold	199,839,000	58,936,000
Net amortization of securities	140,000	113,000
Net change in deferred loan costs and fees	(165,000)	59,000
Gain on sales/calls of securities		(62,000)
Depreciation and amortization	269,000	238,000
Impairment write-downs on foreclosed real estate		150,000
Gain on life insurance settlements, net		(486,000)
ESOP expense	145,000
Increase in cash surrender value of life insurance	(76,000)	(104,000)
Net increase in mortgage servicing rights	(506,000)	(319,000)
Other, net	(608,000)	(61,000)
Net cash used in operating activities	(2,647,000)	(1,642,000)
Cash flows from investing activities:
Redemptions of certificates of deposit	490,000
Securities available for sale:
Calls/maturities	625,000	7,033,000
Purchases		(2,000,000)
Principal payments on mortgage-backed securities	1,527,000	2,917,000
Loan originations, net of principal repayments	(10,104,000)	(9,711,000)
Loans purchased	(22,068,000)	(859,000)
Redemption (purchases) of Federal Home Loan Bank stock	(110,000)	785,000
Proceeds from sale of building		1,231,000
Purchases of premises and equipment	(1,040,000)	(502,000)
Net cash used in investing activities	(30,680,000)	(1,106,000)
Cash flows from financing activities:
Net increase in deposits	17,409,000	14,947,000
Net increase (decrease) in short-term Federal Home Loan Bank borrowings	14,590,000	(7,401,000)
Proceeds from long-term Federal Home Loan Bank advances		12,264,000
Repayments of long-term Federal Home Loan Bank advances	(4,793,000)	(15,709,000)
Net increase (decrease) in mortgagors' escrow accounts	118,000	(135,000)
Stock subsciptions received		67,442,000
Deferred stock offering costs		(452,000)
Repurchase of common stock	(3,000)
Net cash provided by financing activities	27,321,000	70,956,000
Net change in cash and cash equivalents	(6,006,000)	68,208,000
Cash and cash equivalents at beginning of period	14,849,000	4,646,000
Cash and cash equivalents at end of period	8,843,000	72,854,000
Supplemental cash flow information:
Interest paid on deposits and borrowed funds	888,000	763,000
Income taxes paid	$ 3,000	$ 7,000

Conversion and Basis of Present

Conversion and Basis of Presentation	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Conversion and Basis of Presentation	1. CONVERSION AND BASIS OF PRESENTATION Conversion Randolph Bancorp, a Massachusetts-chartered mutual holding company and the parent company of Randolph Savings Bank (the “Bank”), adopted a plan of conversion (the “Plan of Conversion”) in January 2016 which was subsequently approved by Randolph Bancorp’s Corporators in May 2016. Under the Plan of Conversion, Randolph Bancorp converted from a mutual to a stock holding company in a series of transactions in which Randolph Bancorp, Inc. (“Bancorp”), a recently formed subsidiary of Randolph Bancorp, became the surviving entity. On July 1, 2016, the mutual-to-stock transaction was completed and Bancorp sold 5,686,750 shares of its common stock, representing the adjusted maximum of the offering range, at $10.00 per share, for gross proceeds of $56,867,500, including the sale of 469,498 shares to the Bank’s newly formed employee stock ownership plan (“ESOP”). The ESOP’s shares were funded by a loan from Bancorp to be repaid over 25 years with interest at the prime rate. The direct costs of stock offering were deducted from the proceeds of the offering and amounted to $2,325,000. In connection with the Plan of Conversion, Bancorp established The Randolph Savings Charitable Foundation, Inc. (the “Foundation”). The Foundation was funded with 181,976 shares of Bancorp’s common stock and $455,000 in cash. Bancorp recognized expense of $2,274,700 in the third quarter of 2016 for this contribution. The Bancorp and the Bank are required to restrict their net worth by establishing liquidation accounts (collectively, the “liquidation account”) for the benefit of eligible account holders who continue to maintain deposit accounts at the Bank after the conversion. The liquidation account will be reduced annually to the extent eligible depositors reduce their qualifying deposits and cannot be increased thereafter with additional deposits. In the event of a complete liquidation of the Bank, each eligible account holder would be entitled to receive a distribution from the liquidation account in an amount proportionate to the adjusted qualifying account balances then held. Neither the Bancorp 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 the liquidation account. Basis of Financial Statement Presentation The consolidated financial statements include the accounts of Randolph Bancorp, Inc. and its wholly-owned subsidiary, Randolph Savings Bank (together, the “Company”). The Bank has subsidiaries involved in owning investment securities and foreclosed real estate properties and a subsidiary which provides loan closing services. All intercompany accounts and transactions have been eliminated in consolidation. These financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial reporting and with the instructions to Form 10-Q and Article 10 of Regulation S-X issued by the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying interim financial statements do not include all information required under GAAP for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation of the financial statements, primarily consisting of normal recurring adjustments, have been included. The operating results for the six months ended June 30, 2017 are not necessarily indicative of the results to be expected for the year ending December 31, 2017 or any other interim period. For further information, refer to the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016, as filed with the SEC.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2017
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	1. RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the Financial Accounting Standards Board ("FASB") Accounting Standards Update (“ASU”) Revenue from Contracts with Customers In February 2016, FASB issued ASU 2016-02, Leases In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses In April 2017, the FASB issued ASU 2017-08 Receivables – Non-refundable Fees and Other Costs

Acquisition

Acquisition	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Acquisition	1. ACQUISITION On July 1, 2016, the Company acquired all of the outstanding common stock of First Eastern Bankshares Corporation (“First Eastern”) for cash of $14.1 million. The results of operations of First Eastern are included in the Company’s consolidated statements of operations beginning on July 1, 2016. The following table presents selected unaudited pro forma financial information assuming the acquisition was completed on January 1, 2016. The pro forma amounts reflect adjustments related to reversal of non-recurring merger and integration costs and amortization and accretion of acquisition accounting fair value adjustments. No benefit for income taxes is included in the determination of the pro forma net loss due to the Company’s determination to establish a full valuation allowance for its deferred tax assets. The unaudited pro forma financial information does not reflect management’s estimate of any revenue enhancement opportunities or anticipated cost savings nor any adjustments related to the stock offering completed on July 1, 2016. The unaudited pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the combined financial results of the Company and First Eastern had the acquisition transaction actually been completed at the beginning of the period presented, nor does it indicate future results for any interim or annual period. Pro forma basic and diluted earnings (loss) per share are not presented as such information is not being presented as part of our historical financial statements for the three and six months ended June 30, 2016 due to the completion of the stock offering subsequent thereto. Unaudited pro forma financial information for the three and six months ended June 30, 2016 is as follows (in thousands): Three Months Ended Six Months Ended June 30, 2016 June 30, 2016 Net Interest Income $ 3,398 $ 6,668 Non-interest Income 5,484 8,714 Net Income 1,246 1,063 Direct acquisition and merger integration costs associated with the First Eastern business combination are being expensed as incurred and are presented separately in the accompanying statements of operations. Costs incurred during the six months ended June 30, 2016 consist principally of legal and consulting fees. Costs incurred during the six months ended June 30, 2017 consist principally of severance obligations, system conversion costs and consulting fees. Additional merger integration costs are expected to be incurred through the third quarter of 2017.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Accumulated Other Comprehensive Loss	1. ACCUMULATED OTHER COMPREHENSIVE LOSS Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income (loss). Although certain changes in assets and liabilities are reported as a separate component of stockholders’ equity, such items, along with net income (loss), are components of comprehensive income (loss). The components of accumulated other comprehensive loss, included in total stockholders’ equity, are as follows: June 30, December 31, 2017 2016 (In thousands) Securities available for sale: Net unrealized gain (loss) $ 100 $ (698 ) Tax effect (703 ) (423 ) Net-of-tax amount (603 ) (1,121 ) Supplemental retirement plan Unrecognized net actuarial loss (661 ) (679 ) Unrecognized net prior service credit 529 573 (132 ) (106 ) Tax effect (57 ) (57 ) Net-of-tax amount (189 ) (163 ) Accumulated other comprehensive loss $ (792 ) $ (1,284 )

Securities Available for Sale

Securities Available for Sale	6 Months Ended
	Jun. 30, 2017
Investments Debt And Equity Securities [Abstract]
Securities Available for Sale	1. SECURITIES AVAILABLE FOR SALE The amortized cost and fair value of securities available for sale, including gross unrealized gains and losses, are as follows: Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) June 30, 2017 Debt securities: U.S. Government-sponsored enterprises $ 3,999 $ 85 $ (4 ) $ 4,080 Corporate 3,024 45 (6 ) 3,063 Municipal 13,694 342 (3 ) 14,033 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 20,005 180 (344 ) 19,841 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 14,564 85 (300 ) 14,349 U.S. Government-guaranteed 8,882 53 (71 ) 8,864 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 2,001 42 — 2,043 U.S. Government-guaranteed 330 4 — 334 Total debt securities 66,499 836 (728 ) 66,607 Mutual fund 545 — (8 ) 537 Total securities available for sale $ 67,044 $ 836 $ (736 ) $ 67,144 December 31, 2016 Debt securities: U.S. Government-sponsored enterprises $ 3,999 $ 92 $ (10 ) $ 4,081 Corporate 3,044 54 (18 ) 3,080 Municipal 13,857 254 (56 ) 14,055 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 21,130 172 (580 ) 20,722 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 14,676 56 (554 ) 14,178 U.S. Government-guaranteed 9,589 12 (144 ) 9,457 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 2,127 28 — 2,155 U.S. Government-guaranteed 368 3 — 371 Total debt securities 68,790 671 (1,362 ) 68,099 Mutual fund 545 — (7 ) 538 Total securities available for sale $ 69,335 $ 671 $ (1,369 ) $ 68,637 The amortized cost and fair value of debt securities by contractual maturity at June 30, 2017 are presented below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Fair Cost Value (In thousands) Within 1 year $ 3,309 $ 3,333 After 1 year through 5 years 12,180 12,450 After 5 years through 10 years 5,228 5,393 20,717 21,176 Mortgage-backed securities 45,782 45,431 $ 66,499 $ 66,607 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: Less Over Twelve Months Gross Gross Unrealized Fair Unrealized Fair Losses Value Losses Value June 30, 2017 (In thousands) Debt securities: U.S. Government-sponsored enterprises $ (4 ) $ 1,996 $ — $ — Corporate (4 ) 1,034 (2 ) 474 Municipal (1 ) 454 (2 ) 483 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (344 ) 14,129 — — Commercial mortgage-backed securities: U.S. Government-sponsored enterprises (300 ) 8,964 — — U.S. Government-guaranteed (71 ) 4,100 — — Total debt securities (724 ) 30,677 (4 ) 957 Mutual Fund (8 ) 537 — — $ (732 ) $ 31,214 $ (4 ) $ 957 December 31, 2016 Debt securities: U.S. Government-sponsored enterprises $ (10 ) $ 1,990 $ — $ — Corporate (14 ) 519 (4 ) 996 Municipal (46 ) 3,310 (10 ) 477 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (580 ) 16,261 — — Commercial mortgage-backed securities: U.S. Government-sponsored enterprises (554 ) 8,766 — — U.S. Government-guaranteed (144 ) 5,927 — — Total debt securities (1,348 ) 36,773 (14 ) 1,473 Mutual Fund (7 ) 538 — — $ (1,355 ) $ 37,311 $ (14 ) $ 1,473 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 June 30, 2017, 28 debt securities had unrealized losses with aggregate depreciation of less than 2.3% from the Company’s amortized cost basis. The Company currently does not believe it is probable that it will be unable to collect all amounts due according to the contractual terms of these investments. Therefore, it is expected that the bonds would not be settled at a price less than the par value of the investment. Because the Company does not intend to sell any debt securities and it is more likely than not that the Company will not be required to sell any debt securities before recovery of its amortized cost basis, it does not consider these investments to be other-than-temporarily impaired at June 30, 2017. When possible, management actively monitors the credit rating of the underlying issuer of the debt security. As of June 30, 2017 management did not identify any securities for which the credit rating had deteriorated since purchase.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Loans and Allowance for Loan Losses	1. LOANS AND ALLOWANCE FOR LOAN LOSSES A summary of loan portfolio is as follows: June 30, 2017 December 31, 2016 (In thousands) Mortgage loans on real estate: Residential: One-to-four family $ 182,323 $ 179,025 Home equity loans and lines of credit 38,681 35,393 Commercial 93,007 88,394 Construction 24,805 23,629 338,816 326,441 Commercial and industrial 17,181 2,067 Consumer 11,212 6,578 Total loans 367,209 335,086 Allowance for loan losses (3,557 ) (3,271 ) Net deferred loan costs and fees, and purchase premiums 1,341 1,176 $ 364,993 $ 332,991 During the six months ended June 30, 2017, the Company purchased $15.4 million in loan participations originated through a super-regional bank. These loans are to local franchisees of a major international fast food retailer and are classified with commercial and industrial loans in the accompanying table. The Company also purchased $5.0 million of refinanced student loans from an on-line lender specializing in the origination and refinancing of such loans. The following table summarizes the changes in the allowance for loan losses by portfolio segment for the three and six months ended June 30, 2017 and 2016: Second Residential Mortgages Commercial Commercial 1-4 Family and Real Estate Construction and Industrial Consumer Total (In thousands) Three Months Ended June 30, 2017 Allowance at March 31, 2017 $ 821 $ 395 $ 1,519 $ 351 $ 195 $ 156 $ 3,437 Provision (credit) for loan losses (9 ) (57 ) 17 38 47 64 100 Loans charged-off — — — — — (32 ) (32 ) Recoveries 8 — — — 34 10 52 Balance at June 30, 2017 $ 820 $ 338 $ 1,536 $ 389 $ 276 $ 198 $ 3,557 Three Months Ended June 30, 2016 Allowance at March 31, 2016 $ 1,054 $ 431 $ 1,559 $ 121 $ 36 $ 84 $ 3,285 Provision (credit) for loan losses (9 ) 13 (39 ) 14 — 21 — Loans charged-off — — — — — (34 ) (34 ) Recoveries 1 — — — — 7 8 Balance at June 30, 2016 $ 1,046 $ 444 $ 1,520 $ 135 $ 36 $ 78 $ 3,259 Six Months Ended June 30, 2017 Allowance at December 31, 2016 $ 1,018 $ 436 $ 1,410 $ 225 $ 37 $ 145 $ 3,271 Provision (credit) for loan losses (210 ) (98 ) 126 164 204 149 335 Loans charged-off — — — — — (109 ) (109 ) Recoveries 12 — — — 35 13 60 Balance at June 30, 2017 $ 820 $ 338 $ 1,536 $ 389 $ 276 $ 198 $ 3,557 Six Months Ended June 30, 2016 Allowance at December 31, 2015 $ 1,076 $ 512 $ 1,402 $ 159 $ 37 $ 53 $ 3,239 Provision (credit) for loan losses (32 ) (68 ) 118 (24 ) (1 ) 69 62 Loans charged-off — — — — — (60 ) (60 ) Recoveries 2 — — — — 16 18 Balance at June 30, 2016 $ 1,046 $ 444 $ 1,520 $ 135 $ 36 $ 78 $ 3,259 Additional information pertaining to the allowance for loan losses at June 30, 2017 and December 31, 2016 is as follows: Second Residential Mortgages Commercial Commercial 1-4 Family and Real Estate Construction and Industrial Consumer Total June 30, 2017 (In thousands) Allowance for impaired loans $ 177 $ 1 $ 14 $ — $ — $ — $ 192 Allowance for non-impaired loans 643 337 1,522 389 276 198 3,365 Total allowance for loan losses $ 820 $ 338 $ 1,536 $ 389 $ 276 $ 198 $ 3,557 Impaired loans $ 5,145 $ 276 $ 757 $ — $ — $ — $ 6,178 Non-impaired loans 177,178 38,405 92,250 24,805 17,181 11,212 361,031 Total loans $ 182,323 $ 38,681 $ 93,007 $ 24,805 $ 17,181 $ 11,212 $ 367,209 December 31, 2016 Allowance for impaired loans $ 190 $ 2 $ 8 $ — $ — $ — $ 200 Allowance for non-impaired loans 828 434 1,402 225 37 145 3,071 Total allowance for loan losses $ 1,018 $ 436 $ 1,410 $ 225 $ 37 $ 145 $ 3,271 Impaired loans $ 4,506 $ 276 $ 832 $ — $ — $ — $ 5,614 Non-impaired loans 174,519 35,117 87,562 23,629 2,067 6,578 329,472 Total loans $ 179,025 $ 35,393 $ 88,394 $ 23,629 $ 2,067 $ 6,578 $ 335,086 The following is a summary of past due and non-accrual loans at June 30, 2017 and December 31, 2016: 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due Non-accrual Loans (In thousands) June 30, 2017 Residential one-to-four family $ 501 $ 142 $ — $ 643 $ 1,960 Home equity loans and lines of credit 204 — — 204 276 Commercial real estate — — — — — Construction — — — — — Commercial and industrial — — — — — Consumer — — — — — Total $ 705 $ 142 $ — $ 847 $ 2,236 December 31, 2016 Residential one-to-four family $ 1,168 $ 201 $ — $ 1,369 $ 1,945 Home equity loans and lines of credit 258 — — 258 276 Commercial real estate 400 — — 400 — Construction — — — — — Commercial and industrial — — — — — Consumer 59 — — 59 — Total $ 1,885 $ 201 $ - $ 2,086 $ 2,221 At June 30, 2017 and December 31, 2016, there were no loans past due 90 days or more and still accruing interest. The following is a summary of impaired loans at June 30, 2017 and December 31, 2016: Recorded Investment Unpaid Principal Balance Related Allowance (In thousands) June 30, 2017 Impaired loans without a valuation allowance: Residential one-to-four family $ 2,588 $ 2,543 Home equity loans and lines of credit 247 247 Commercial real estate 251 252 Total 3,086 3,042 Impaired loans with a valuation allowance: Residential one-to-four family 2,621 2,602 $ 177 Home equity loans and lines of credit 30 29 1 Commercial real estate 505 505 14 Total 3,156 3,136 192 Total impaired loans $ 6,242 $ 6,178 $ 192 December 31, 2016 Impaired loans without a valuation allowance: Residential one-to-four family $ 1,922 $ 1,877 Home equity loans and lines of credit 246 246 Commercial real estate 270 270 Total 2,438 2,393 Impaired loans with a valuation allowance: Residential one-to-four family 2,648 2,629 $ 190 Home equity loans and lines of credit 31 30 2 Commercial real estate 562 562 8 Total 3,241 3,221 200 Total impaired loans $ 5,679 $ 5,614 $ 200 Additional information pertaining to impaired loans follows: Average Interest Cash Basis Recorded Income Interest Investment Recognized Recognized (In thousands) Six Months Ended June 30, 2017 Residential one-to-four family $ 4,782 $ 99 $ 46 Home equity loans and lines of credit 276 1 1 Commercial real estate 788 18 — Total $ 5,846 $ 118 $ 47 Six Months Ended June 30, 2016 Residential one-to-four family $ 4,942 $ 89 $ 29 Home equity loans and lines of credit 241 1 1 Commercial real estate 1,304 33 — Commercial and industrial 12 — — Total $ 6,499 $ 123 $ 30 Three Months Ended June 30, 2017 Residential one-to-four family $ 4,964 $ 55 $ 27 Home equity loans and lines of credit 276 — — Commercial real estate 770 9 — Total $ 6,010 $ 64 $ 27 Three Months Ended June 30, 2016 Residential one-to-four family $ 4,783 $ 48 $ 16 Home equity loans and lines of credit 288 1 1 Commercial real estate 1,236 17 — Total $ 6,307 $ 66 $ 17 No additional funds are committed to be advanced in connection with impaired loans. Troubled Debt Restructurings The Company periodically grants concessions to borrowers experiencing financial difficulties. At June 30, 2017, the Company had 19 residential real estate loans and 3 commercial real estate loans aggregating $4,449,000 and $553,000, respectively, which were subject to troubled debt restructuring agreements. At June 30, 2016, the Company had 18 residential real estate loans and 5 commercial real estate loans aggregating $4,548,000 and $1,010,000, respectively, which were subject to troubled debt restructuring agreements. As of June 30, 2017 and 2016, $4,006,000 and $3,859,000, respectively, in troubled debt restructurings were performing in accordance with the terms of the modified loan agreements. Included in such amounts are $997,000 and $1,729,000, respectively, that are being accounted for as non-accrual loans. For the six months ended June 30, 2017 and 2016 the Company did not enter into any loan modifications meeting the criteria of a troubled debt restructuring. Management performs a discounted cash flow calculation to determine the amount of valuation reserve required on each of the troubled debt restructurings. Any reserve required is recorded as part of the allowance for loan losses. During the three and six months ended June 30, 2017 and 2016, there were no material changes to the allowance for loan losses as a result of loan modifications made which were considered a troubled debt restructuring. During the three and six months ended June 30, 2017 and 2016, there were no troubled debt restructurings that defaulted (over 30 days past due) within twelve months of the restructure date. Credit Quality Information The Company utilizes an eight-grade internal loan rating system for commercial real estate, construction and commercial loans, as follows: Loans rated 1 – 3A are considered “pass” rated loans with low to average risk. Loans rated 4 are considered “special mention.” These loans are starting to show signs of potential weakness and are being closely monitored by management. Loans rated 5 are considered “substandard” and are 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. Loans rated 6 are considered “doubtful” and have all the weaknesses inherent in those classified substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, highly questionable and improbable. Loans rated 7 are considered uncollectible (“loss”) and of such little value that their continuance as loans is not warranted. On an annual basis, or more often if needed, the Company formally reviews the ratings on all commercial real estate, construction and commercial and industrial loans. 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. The following table presents the Company’s loans by risk rating at the dates indicated: June 30, 2017 December 31, 2016 Commercial Real Construction Commercial and Industrial Commercial Real Construction Commercial and Industrial (In thousands) Loans rated 1 - 3A (Pass rated) $ 92,803 $ 24,805 $ 17,181 $ 88,186 $ 23,286 $ 2,067 Loans rated 4 — — — — 343 — Loans rated 5 204 — — 208 — — $ 93,007 $ 24,805 $ 17,181 $ 88,394 $ 23,629 $ 2,067 Residential mortgages, home equity loans and lines of credit, and consumer loans are monitored for credit quality based primarily on their payment status. When one these loans becomes more than 90 days delinquent it is assigned an internal loan rating. At June 30, 2017, $339,000 in residential mortgages and $29,000 in home equity loans were rated as substandard and $2,098,000 in residential mortgages and $370,000 in home equity loans were rated as special mention. At December 31, 2016, $890,000 in residential mortgages were rated as substandard and $1,471,000 in residential mortgages and $400,000 in home equity loans were rated as special mention.

Loan Servicing

Loan Servicing	6 Months Ended
	Jun. 30, 2017
Transfers And Servicing [Abstract]
Loan Servicing	1. LOAN SERVICING Mortgage loans serviced for others are not included in the accompanying consolidated balance sheets. The unpaid principal balances of residential mortgage loans serviced for others were $1,097,334,000 and $1,046,551,000 at June 30, 2017 and December 31, 2016, respectively. The following table summarizes the activity relating to mortgage servicing rights for the six months ended June 30, 2017 and 2016 (in thousands): June 30, 2017 June 30, 2016 Mortgage servicing rights: Balance at beginning of year $ 8,910 $ 2,601 Additions through originations 946 439 Amortization (671 ) (213 ) Balance at end of period $ 9,185 $ 2,827 Valuation allowance: Balance at beginning of year $ 424 $ 34 Provision (credit) (231 ) 25 Balance at end of period $ 193 $ 59 Amortized cost, net $ 8,992 $ 2,768 Fair value $ 9,014 $ 2,898 During the six months ended June 30, 2017, the Company recorded a partial reversal of the valuation allowance for its mortgage servicing rights of $231,000 due to an increase in fair value caused by lower expected loan prepayments.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	1. INCOME TAXES During the six months ended June 30, 2017 and 2016, the Company recorded a deferred income tax benefit of $280,000 and $0, respectively, and current state tax expense of $3,000 in each period. The deferred income tax benefit for the 2017 period resulted from, and was limited to, an offsetting tax provision attributable to other comprehensive income, specifically, appreciation in the fair value of available-for-sale securities. Since 2014, the Company has maintained a valuation allowance for all of its deferred tax assets based on a determination that it was more likely than not that such assets would not be realized. This determination was based on the Company’s net operating loss (“NOL”) carryforward position, its current period operating results exclusive of non-recurring items and its expectations for the upcoming year. In performing subsequent assessments, management has concluded that no significant changes in the key factors affecting the realizability of the deferred tax asset has occurred and that a valuation allowance for all deferred tax assets should be maintained.

On-Balance Sheet Derivative Ins

On-Balance Sheet Derivative Instruments and Hedging Activities	6 Months Ended
	Jun. 30, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
On-Balance Sheet Derivative Instruments and Hedging Activities	1. ON-BALANCE SHEET DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Derivative Loan Commitments Mortgage loan commitments qualify as derivative loan commitments if the loan that will result from exercise of the commitment will be held for sale upon funding. The Company enters into commitments to fund residential mortgage loans at specified rates and times in the future, with the intention that these loans will subsequently be sold in the secondary market. Outstanding derivative loan commitments expose the Company to the risk that the price of the loans arising from exercise of the loan commitment might decline from inception of the rate lock to funding of the loan due to an increase in mortgage interest rates. If interest rates increase, the value of these loan commitments decreases. Conversely, if interest rates decrease, the value of these loan commitments increases. The notional amount of derivative loan commitments was $42,901,000 and $32,904,000 at June 30, 2017 and December 31, 2016, respectively. The fair value of such commitments was an asset of $538,000 and $617,000 as of June 30, 2017 and December 31, 2016, respectively, and is included in other assets in the consolidated balance sheets. Forward Loan Sale Commitments The Company utilizes both “mandatory delivery” and “best efforts” forward loan sale commitments to mitigate the risk of potential decreases in the values of loans that would result from the exercise of the derivative loan commitments. With a “mandatory delivery” contract, the Company commits to deliver a certain principal amount of mortgage loans to an investor at a specified price on or before a specified date. If the Company fails to deliver the amount of mortgages necessary to fulfill the commitment by the specified date, it is obligated to pay a “pair-off” fee, based on then-current market prices, to the investor to compensate the investor for the shortfall. With a “best efforts” contract, the Company commits to deliver an individual mortgage loan of a specified principal amount and quality to an investor if the loan to the underlying borrower closes. Generally, the price the investor will pay the seller for an individual loan is specified prior to the loan being funded (e.g. on the same day the lender commits to lend funds to a potential borrower). The Company does not account for best efforts contracts as derivative instruments, as such contracts do not require payment of a pair-off fee if the underlying mortgage loan does not close. The Company expects that these forward loan sale commitments will experience inverse changes in fair value to the change in fair value of derivative loan commitments. The notional amount of mandatory delivery forward loan sale commitments was $21,445,000 and $18,197,000 at June 30, 2017 and December 31, 2016, at June 30, 2017 and December 31, 2016, at June 30, 2017 and December 31, 2016,

Employee Stock Ownership Plan

Employee Stock Ownership Plan	6 Months Ended
	Jun. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Employee Stock Ownership Plan	1. EMPLOYEE STOCK OWNERSHIP PLAN In connection with our mutual-to-stock conversion and stock offering, the Company established an employee stock ownership plan (“ESOP) which acquired 469,498 shares of the Company’s common stock equaling 8% of the shares issued, including shares issued to the Foundation. The ESOP is a tax-qualified retirement plan providing employees the opportunity to own Company stock. Company contributions to the ESOP are allocated to eligible participants on the basis of compensation, subject to federal tax limits. The number of shares to be allocated annually is 18,780 through 2040. Shares are committed to be released on a monthly basis and allocated as of December 31 each year. During the three and six month periods ended June 30, 2017, 4,695 shares and 9,390 shares, respectively, were committed to be released, resulting in compensation expense, based on the fair value of the Company’s stock, of $73,000 and $145,000, respectively. The fair value of the 441,328 unallocated shares at June 30, 2017 was $7,017,100.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	1. EARNINGS (LOSS) PER SHARE Basic earnings (loss) per share represents net income (loss) divided by the weighted average of common shares outstanding during the period. Unallocated ESOP shares are not considered to be outstanding for purposes of computing earnings (loss) per share. There were no potentially dilutive common stock equivalents outstanding at The cost of shares issued to the ESOP, but not yet allocated or committed to be released to participants, is shown as a reduction of stockholders’ equity. During the three and six months ended June 30, 2017,

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	1. FAIR VALUE OF ASSETS AND LIABILITIES Determination of fair value The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various assets and liabilities. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the asset or liability. Effective July 1, 2016, the Company elected the fair value option pursuant to Accounting Standards Codification (“ASC”) 825, “Financial Instruments” for its residential mortgage loans being held for sale in the secondary market. ASC 825 allows for the irrevocable option to elect fair value accounting for the initial and subsequent measurement for certain financial assets and liabilities on a contract-by-contract basis that may otherwise not be required to be measured at fair value under other accounting standards. The Company elected the fair value option to better match changes in fair values of the loans with changes in the fair value of the forward loan sale commitments which are used to economically hedge them against changes in interest rates between the time an interest rate lock agreement is entered into with the borrower and the time the completed loan is sold. The aggregate fair value of the loans held for sale, the contractual balance of loans held for sale and the gain on loans held for sale totaled $32.0 million, $31.3 million and $703,000, respectively, at June 30, 2017. The gain on loans held for sale is reported as a component of net gain on sales of mortgage loans in the accompanying statement of operations for the three and six months ended June 30, 2017. The following methods and assumptions were used by the Company in estimating fair value disclosures: Cash and cash equivalents Certificates of deposit Securities Federal Home Loan Bank of Boston (“FHLBB”) stock Loans held for sale Fair values are based on commitments in effect from investors or prevailing market prices and include the servicing value of the loans. Loans Mortgage servicing rights Deposit liabilities FHLBB advances Accrued interest On-balance-sheet derivatives Off-balance sheet credit-related instruments 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. Total Level 1 Level 2 Level 3 Fair (In thousands) June 30, 2017 Assets: Securities available for sale: Debt securities $ — $ 66,607 $ — $ 66,607 Mutual fund — 537 — 537 Loans held for sale — 32,036 — 32,036 Derivative loan commitments — 538 — 538 Forward loan sale commitments — 69 — 69 Liabilities: Forward loan sale commitments — 18 — 18 December 31, 2016 Assets: Securities available for sale: Debt securities $ — $ 68,099 $ — $ 68,099 Mutual fund — 538 — 538 Loans held for sale — 30,452 — 30,452 Derivative loan commitments — 617 — 617 Forward loan sale commitments — 65 — 65 Liabilities: Forward loan sale commitments — 47 — 47 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 non-recurring basis in accordance with U.S. 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. The following table summarizes the fair value hierarchy used to determine each adjustment and the carrying value of the related assets as of June 30, 2017 and December 31, 2016. June 30, 2017 Level 1 Level 2 Level 3 (In thousands) Collateral dependent impaired loans $ — $ — $ 1,274 Mortgage servicing rights — 8,992 — $ — $ 8,992 $ 1,274 December 31, 2016 Level 1 Level 2 Level 3 (In thousands) Collateral dependent impaired loans $ — $ — $ 518 Mortgage servicing rights — 8,486 — $ — $ 8,486 $ 518 The fair value of properties associated with collateral dependent impaired loans are based on recent appraisals for which no discounts were applied. The Company recorded a partial reversal of the valuation allowance for its mortgage servicing rights of $231,000 during the six months ended June 30, 2017 There were no liabilities measured at fair value on a non-recurring basis at June 30, 2017 and December 31, 2016. Summary of fair values of financial instruments The estimated fair values, and related carrying amounts, of the Company’s financial instruments are presented below. Certain financial instruments and all non-financial instruments are exempt from disclosure requirements. Accordingly, the aggregate fair value amounts presented herein do not represent the underlying fair value of the Company. This table excludes financial instruments for which the carrying amount approximates fair value. Financial assets for which the fair value approximates carrying value include cash and cash equivalents, and accrued interest receivable. Financial liabilities for which the fair value approximates carrying value include mortgagors’ escrow accounts and accrued interest payable. June 30, 2017 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 3,185 $ 3,195 $ — $ 3,195 $ — Securities available for sale 67,144 67,144 — 67,144 — Loans held for sale 32,036 32,036 — 32,036 — Loans, net 364,993 362,000 — — 362,000 Derivative assets 607 607 — 607 — Financial liabilities: Deposits $ 368,588 $ 368,285 $ — $ 368,285 $ — FHLBB advances 48,464 48,370 — 48,370 — Derivative liabilities 18 18 — 18 — December 31, 2016 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 3,675 $ 3,687 $ — $ 3,687 $ — Securities available for sale 68,637 68,637 — 68,637 — Loans held for sale 30,452 30,452 — 30,452 — Loans, net 332,991 331,132 — — 331,132 Derivative assets 682 682 — 682 — Financial liabilities: Deposits $ 351,179 350,979 $ — $ 350,979 $ — FHLBB advances 38,667 38,531 — 38,531 — Derivative liabilities 47 47 — 47 —

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1. COMMITMENTS AND CONTINGENCIES 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. These instruments involve, to varying degrees, elements of market, credit and interest rate risk which are not recognized in the consolidated financial statements. The Company’s exposure to credit loss is represented by the contractual amount of these commitments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance-sheet instruments. The following financial instruments were outstanding, at the dates indicated, whose contract amounts represent credit risk: June 30, 2017 December 31, 2016 (In thousands) Commitments to originate loans $ 52,333 $ 35,682 Unused lines and letters of credit 37,963 37,045 Unadvanced funds on construction loans 10,867 9,321 Overdraft lines of credit 9,140 9,189 Commitment under master loan participation agreement 4,554 — 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 generally have fixed expiration dates or other termination clauses and may require payment of a fee. The commitments for lines of credit may expire without being drawn upon. Therefore, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The majority of these financial instruments are collateralized by real estate. At June 30, 2017, we had $52.3 million in loan commitments outstanding, including $42.9 million related to loans to be sold in the secondary mortgage market and for which the Company had $30.8 million in forward loan sale commitments from investors. Lease commitments During the six months ended June 30, 2017, the Company entered into a non-cancelable lease related to its lending center in Andover, MA. This lease has an initial lease term of five years, with an option to extend for an additional period of five years. In addition, the Company entered into a non-cancelable lease with a five-year initial lease term and two five-year renewal options for a new branch office in Braintree, MA. This branch is not expected to open until the first quarter of 2018, at which time customers of our North Randolph, MA branch are expected to be transferred to this new branch location. The aggregate future minimum rent commitment associated with these leases was $2.5 million as of June 30, 2017. Other contingencies We are not currently a party to any pending legal proceedings that we believe would have a material adverse effect on our financial condition, results of operations or cash flows.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	1. SUBSEQUENT EVENT On July 31, 2017, the Company sold the servicing rights to a portfolio of $379 million of residential mortgage loans to a third party. All required approvals necessary to complete this transaction have been received. Under the terms of the purchase and sale agreement, the Company received 70% of the selling price, which amounted to $2.4 million, on the sale date. The final selling price will be adjusted for loan prepayments through November 30, 2017. The Company expects the ultimate net gain or loss on this sale to be insignificant. The actual transfer of servicing is scheduled to occur in September 2017.

Conversion and Basis of Prese22

Conversion and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Basis of Financial Statement Presentation	Basis of Financial Statement Presentation The consolidated financial statements include the accounts of Randolph Bancorp, Inc. and its wholly-owned subsidiary, Randolph Savings Bank (together, the “Company”). The Bank has subsidiaries involved in owning investment securities and foreclosed real estate properties and a subsidiary which provides loan closing services. All intercompany accounts and transactions have been eliminated in consolidation. These financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial reporting and with the instructions to Form 10-Q and Article 10 of Regulation S-X issued by the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying interim financial statements do not include all information required under GAAP for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation of the financial statements, primarily consisting of normal recurring adjustments, have been included. The operating results for the six months ended June 30, 2017 are not necessarily indicative of the results to be expected for the year ending December 31, 2017 or any other interim period. For further information, refer to the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016, as filed with the SEC.
Recent Accounting Pronouncements	In February 2016, FASB issued ASU 2016-02, Leases In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses In April 2017, the FASB issued ASU 2017-08 Receivables – Non-refundable Fees and Other Costs

Acquisition (Tables)

Acquisition (Tables)	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Summary of Unaudited Pro Forma Financial Information	Unaudited pro forma financial information for the three and six months ended June 30, 2016 is as follows (in thousands): Three Months Ended Six Months Ended June 30, 2016 June 30, 2016 Net Interest Income $ 3,398 $ 6,668 Non-interest Income 5,484 8,714 Net Income 1,246 1,063

Accumulated Other Comprehensi24

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Components of Accumulated Other Comprehensive Loss and Related Tax Effects	The components of accumulated other comprehensive loss, included in total stockholders’ equity, are as follows: June 30, December 31, 2017 2016 (In thousands) Securities available for sale: Net unrealized gain (loss) $ 100 $ (698 ) Tax effect (703 ) (423 ) Net-of-tax amount (603 ) (1,121 ) Supplemental retirement plan Unrecognized net actuarial loss (661 ) (679 ) Unrecognized net prior service credit 529 573 (132 ) (106 ) Tax effect (57 ) (57 ) Net-of-tax amount (189 ) (163 ) Accumulated other comprehensive loss $ (792 ) $ (1,284 )

Securities Available for Sale (

Securities Available for Sale (Tables)	6 Months Ended
	Jun. 30, 2017
Investments Debt And Equity Securities [Abstract]
Schedule of amortized cost and fair value of securities	The amortized cost and fair value of securities available for sale, including gross unrealized gains and losses, are as follows: Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) June 30, 2017 Debt securities: U.S. Government-sponsored enterprises $ 3,999 $ 85 $ (4 ) $ 4,080 Corporate 3,024 45 (6 ) 3,063 Municipal 13,694 342 (3 ) 14,033 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 20,005 180 (344 ) 19,841 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 14,564 85 (300 ) 14,349 U.S. Government-guaranteed 8,882 53 (71 ) 8,864 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 2,001 42 — 2,043 U.S. Government-guaranteed 330 4 — 334 Total debt securities 66,499 836 (728 ) 66,607 Mutual fund 545 — (8 ) 537 Total securities available for sale $ 67,044 $ 836 $ (736 ) $ 67,144 December 31, 2016 Debt securities: U.S. Government-sponsored enterprises $ 3,999 $ 92 $ (10 ) $ 4,081 Corporate 3,044 54 (18 ) 3,080 Municipal 13,857 254 (56 ) 14,055 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 21,130 172 (580 ) 20,722 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 14,676 56 (554 ) 14,178 U.S. Government-guaranteed 9,589 12 (144 ) 9,457 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 2,127 28 — 2,155 U.S. Government-guaranteed 368 3 — 371 Total debt securities 68,790 671 (1,362 ) 68,099 Mutual fund 545 — (7 ) 538 Total securities available for sale $ 69,335 $ 671 $ (1,369 ) $ 68,637
Investments Classified by Contractual Maturity Date	The amortized cost and fair value of debt securities by contractual maturity at June 30, 2017 are presented below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Fair Cost Value (In thousands) Within 1 year $ 3,309 $ 3,333 After 1 year through 5 years 12,180 12,450 After 5 years through 10 years 5,228 5,393 20,717 21,176 Mortgage-backed securities 45,782 45,431 $ 66,499 $ 66,607
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	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: Less Over Twelve Months Gross Gross Unrealized Fair Unrealized Fair Losses Value Losses Value June 30, 2017 (In thousands) Debt securities: U.S. Government-sponsored enterprises $ (4 ) $ 1,996 $ — $ — Corporate (4 ) 1,034 (2 ) 474 Municipal (1 ) 454 (2 ) 483 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (344 ) 14,129 — — Commercial mortgage-backed securities: U.S. Government-sponsored enterprises (300 ) 8,964 — — U.S. Government-guaranteed (71 ) 4,100 — — Total debt securities (724 ) 30,677 (4 ) 957 Mutual Fund (8 ) 537 — — $ (732 ) $ 31,214 $ (4 ) $ 957 December 31, 2016 Debt securities: U.S. Government-sponsored enterprises $ (10 ) $ 1,990 $ — $ — Corporate (14 ) 519 (4 ) 996 Municipal (46 ) 3,310 (10 ) 477 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (580 ) 16,261 — — Commercial mortgage-backed securities: U.S. Government-sponsored enterprises (554 ) 8,766 — — U.S. Government-guaranteed (144 ) 5,927 — — Total debt securities (1,348 ) 36,773 (14 ) 1,473 Mutual Fund (7 ) 538 — — $ (1,355 ) $ 37,311 $ (14 ) $ 1,473

Loans and Allowance for Loan 26

Loans and Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Summary of Loan Portfolio	A summary of loan portfolio is as follows: June 30, 2017 December 31, 2016 (In thousands) Mortgage loans on real estate: Residential: One-to-four family $ 182,323 $ 179,025 Home equity loans and lines of credit 38,681 35,393 Commercial 93,007 88,394 Construction 24,805 23,629 338,816 326,441 Commercial and industrial 17,181 2,067 Consumer 11,212 6,578 Total loans 367,209 335,086 Allowance for loan losses (3,557 ) (3,271 ) Net deferred loan costs and fees, and purchase premiums 1,341 1,176 $ 364,993 $ 332,991
Summary of Changes in the Allowance for Loan Losses by Portfolio Segment	The following table summarizes the changes in the allowance for loan losses by portfolio segment for the three and six months ended June 30, 2017 and 2016: Second Residential Mortgages Commercial Commercial 1-4 Family and Real Estate Construction and Industrial Consumer Total (In thousands) Three Months Ended June 30, 2017 Allowance at March 31, 2017 $ 821 $ 395 $ 1,519 $ 351 $ 195 $ 156 $ 3,437 Provision (credit) for loan losses (9 ) (57 ) 17 38 47 64 100 Loans charged-off — — — — — (32 ) (32 ) Recoveries 8 — — — 34 10 52 Balance at June 30, 2017 $ 820 $ 338 $ 1,536 $ 389 $ 276 $ 198 $ 3,557 Three Months Ended June 30, 2016 Allowance at March 31, 2016 $ 1,054 $ 431 $ 1,559 $ 121 $ 36 $ 84 $ 3,285 Provision (credit) for loan losses (9 ) 13 (39 ) 14 — 21 — Loans charged-off — — — — — (34 ) (34 ) Recoveries 1 — — — — 7 8 Balance at June 30, 2016 $ 1,046 $ 444 $ 1,520 $ 135 $ 36 $ 78 $ 3,259 Six Months Ended June 30, 2017 Allowance at December 31, 2016 $ 1,018 $ 436 $ 1,410 $ 225 $ 37 $ 145 $ 3,271 Provision (credit) for loan losses (210 ) (98 ) 126 164 204 149 335 Loans charged-off — — — — — (109 ) (109 ) Recoveries 12 — — — 35 13 60 Balance at June 30, 2017 $ 820 $ 338 $ 1,536 $ 389 $ 276 $ 198 $ 3,557 Six Months Ended June 30, 2016 Allowance at December 31, 2015 $ 1,076 $ 512 $ 1,402 $ 159 $ 37 $ 53 $ 3,239 Provision (credit) for loan losses (32 ) (68 ) 118 (24 ) (1 ) 69 62 Loans charged-off — — — — — (60 ) (60 ) Recoveries 2 — — — — 16 18 Balance at June 30, 2016 $ 1,046 $ 444 $ 1,520 $ 135 $ 36 $ 78 $ 3,259
Summary of Additional Information Pertaining to the Allowance for Loan Losses	Additional information pertaining to the allowance for loan losses at June 30, 2017 and December 31, 2016 is as follows: Second Residential Mortgages Commercial Commercial 1-4 Family and Real Estate Construction and Industrial Consumer Total June 30, 2017 (In thousands) Allowance for impaired loans $ 177 $ 1 $ 14 $ — $ — $ — $ 192 Allowance for non-impaired loans 643 337 1,522 389 276 198 3,365 Total allowance for loan losses $ 820 $ 338 $ 1,536 $ 389 $ 276 $ 198 $ 3,557 Impaired loans $ 5,145 $ 276 $ 757 $ — $ — $ — $ 6,178 Non-impaired loans 177,178 38,405 92,250 24,805 17,181 11,212 361,031 Total loans $ 182,323 $ 38,681 $ 93,007 $ 24,805 $ 17,181 $ 11,212 $ 367,209 December 31, 2016 Allowance for impaired loans $ 190 $ 2 $ 8 $ — $ — $ — $ 200 Allowance for non-impaired loans 828 434 1,402 225 37 145 3,071 Total allowance for loan losses $ 1,018 $ 436 $ 1,410 $ 225 $ 37 $ 145 $ 3,271 Impaired loans $ 4,506 $ 276 $ 832 $ — $ — $ — $ 5,614 Non-impaired loans 174,519 35,117 87,562 23,629 2,067 6,578 329,472 Total loans $ 179,025 $ 35,393 $ 88,394 $ 23,629 $ 2,067 $ 6,578 $ 335,086
Schedule of Past Due and Non-Accrual Loans	The following is a summary of past due and non-accrual loans at June 30, 2017 and December 31, 2016: 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due Non-accrual Loans (In thousands) June 30, 2017 Residential one-to-four family $ 501 $ 142 $ — $ 643 $ 1,960 Home equity loans and lines of credit 204 — — 204 276 Commercial real estate — — — — — Construction — — — — — Commercial and industrial — — — — — Consumer — — — — — Total $ 705 $ 142 $ — $ 847 $ 2,236 December 31, 2016 Residential one-to-four family $ 1,168 $ 201 $ — $ 1,369 $ 1,945 Home equity loans and lines of credit 258 — — 258 276 Commercial real estate 400 — — 400 — Construction — — — — — Commercial and industrial — — — — — Consumer 59 — — 59 — Total $ 1,885 $ 201 $ - $ 2,086 $ 2,221
Summary of Impaired Loans and Additional Information Pertaining to Impaired Loans	The following is a summary of impaired loans at June 30, 2017 and December 31, 2016: Recorded Investment Unpaid Principal Balance Related Allowance (In thousands) June 30, 2017 Impaired loans without a valuation allowance: Residential one-to-four family $ 2,588 $ 2,543 Home equity loans and lines of credit 247 247 Commercial real estate 251 252 Total 3,086 3,042 Impaired loans with a valuation allowance: Residential one-to-four family 2,621 2,602 $ 177 Home equity loans and lines of credit 30 29 1 Commercial real estate 505 505 14 Total 3,156 3,136 192 Total impaired loans $ 6,242 $ 6,178 $ 192 December 31, 2016 Impaired loans without a valuation allowance: Residential one-to-four family $ 1,922 $ 1,877 Home equity loans and lines of credit 246 246 Commercial real estate 270 270 Total 2,438 2,393 Impaired loans with a valuation allowance: Residential one-to-four family 2,648 2,629 $ 190 Home equity loans and lines of credit 31 30 2 Commercial real estate 562 562 8 Total 3,241 3,221 200 Total impaired loans $ 5,679 $ 5,614 $ 200 Additional information pertaining to impaired loans follows: Average Interest Cash Basis Recorded Income Interest Investment Recognized Recognized (In thousands) Six Months Ended June 30, 2017 Residential one-to-four family $ 4,782 $ 99 $ 46 Home equity loans and lines of credit 276 1 1 Commercial real estate 788 18 — Total $ 5,846 $ 118 $ 47 Six Months Ended June 30, 2016 Residential one-to-four family $ 4,942 $ 89 $ 29 Home equity loans and lines of credit 241 1 1 Commercial real estate 1,304 33 — Commercial and industrial 12 — — Total $ 6,499 $ 123 $ 30 Three Months Ended June 30, 2017 Residential one-to-four family $ 4,964 $ 55 $ 27 Home equity loans and lines of credit 276 — — Commercial real estate 770 9 — Total $ 6,010 $ 64 $ 27 Three Months Ended June 30, 2016 Residential one-to-four family $ 4,783 $ 48 $ 16 Home equity loans and lines of credit 288 1 1 Commercial real estate 1,236 17 — Total $ 6,307 $ 66 $ 17
Summary of Company's Loans by Risk Rating	The following table presents the Company’s loans by risk rating at the dates indicated: June 30, 2017 December 31, 2016 Commercial Real Construction Commercial and Industrial Commercial Real Construction Commercial and Industrial (In thousands) Loans rated 1 - 3A (Pass rated) $ 92,803 $ 24,805 $ 17,181 $ 88,186 $ 23,286 $ 2,067 Loans rated 4 — — — — 343 — Loans rated 5 204 — — 208 — — $ 93,007 $ 24,805 $ 17,181 $ 88,394 $ 23,629 $ 2,067

Loan Servicing (Tables)

Loan Servicing (Tables)	6 Months Ended
	Jun. 30, 2017
Transfers And Servicing [Abstract]
Summary of Activity Relating to Mortgage Servicing Rights	The following table summarizes the activity relating to mortgage servicing rights for the six months ended June 30, 2017 and 2016 (in thousands): June 30, 2017 June 30, 2016 Mortgage servicing rights: Balance at beginning of year $ 8,910 $ 2,601 Additions through originations 946 439 Amortization (671 ) (213 ) Balance at end of period $ 9,185 $ 2,827 Valuation allowance: Balance at beginning of year $ 424 $ 34 Provision (credit) (231 ) 25 Balance at end of period $ 193 $ 59 Amortized cost, net $ 8,992 $ 2,768 Fair value $ 9,014 $ 2,898

Fair Value of Assets and Liab28

Fair Value of Assets and Liabilities (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of 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. Total Level 1 Level 2 Level 3 Fair (In thousands) June 30, 2017 Assets: Securities available for sale: Debt securities $ — $ 66,607 $ — $ 66,607 Mutual fund — 537 — 537 Loans held for sale — 32,036 — 32,036 Derivative loan commitments — 538 — 538 Forward loan sale commitments — 69 — 69 Liabilities: Forward loan sale commitments — 18 — 18 December 31, 2016 Assets: Securities available for sale: Debt securities $ — $ 68,099 $ — $ 68,099 Mutual fund — 538 — 538 Loans held for sale — 30,452 — 30,452 Derivative loan commitments — 617 — 617 Forward loan sale commitments — 65 — 65 Liabilities: Forward loan sale commitments — 47 — 47
Schedule of Assets Measured at Fair Value on a Non-Recurring Basis	The following table summarizes the fair value hierarchy used to determine each adjustment and the carrying value of the related assets as of June 30, 2017 and December 31, 2016. June 30, 2017 Level 1 Level 2 Level 3 (In thousands) Collateral dependent impaired loans $ — $ — $ 1,274 Mortgage servicing rights — 8,992 — $ — $ 8,992 $ 1,274 December 31, 2016 Level 1 Level 2 Level 3 (In thousands) Collateral dependent impaired loans $ — $ — $ 518 Mortgage servicing rights — 8,486 — $ — $ 8,486 $ 518
Summary of Carrying Values, Estimated Fair Values and Placement in Fair Value Hierarchy of Company's Financial Instruments	Summary of fair values of financial instruments The estimated fair values, and related carrying amounts, of the Company’s financial instruments are presented below. Certain financial instruments and all non-financial instruments are exempt from disclosure requirements. Accordingly, the aggregate fair value amounts presented herein do not represent the underlying fair value of the Company. This table excludes financial instruments for which the carrying amount approximates fair value. Financial assets for which the fair value approximates carrying value include cash and cash equivalents, and accrued interest receivable. Financial liabilities for which the fair value approximates carrying value include mortgagors’ escrow accounts and accrued interest payable. June 30, 2017 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 3,185 $ 3,195 $ — $ 3,195 $ — Securities available for sale 67,144 67,144 — 67,144 — Loans held for sale 32,036 32,036 — 32,036 — Loans, net 364,993 362,000 — — 362,000 Derivative assets 607 607 — 607 — Financial liabilities: Deposits $ 368,588 $ 368,285 $ — $ 368,285 $ — FHLBB advances 48,464 48,370 — 48,370 — Derivative liabilities 18 18 — 18 — December 31, 2016 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 3,675 $ 3,687 $ — $ 3,687 $ — Securities available for sale 68,637 68,637 — 68,637 — Loans held for sale 30,452 30,452 — 30,452 — Loans, net 332,991 331,132 — — 331,132 Derivative assets 682 682 — 682 — Financial liabilities: Deposits $ 351,179 350,979 $ — $ 350,979 $ — FHLBB advances 38,667 38,531 — 38,531 — Derivative liabilities 47 47 — 47 —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2017
Commitments And Contingencies Disclosure [Abstract]
Summary of Financial Instruments Outstanding Contract Amounts Represent Credit Risk	The following financial instruments were outstanding, at the dates indicated, whose contract amounts represent credit risk: June 30, 2017 December 31, 2016 (In thousands) Commitments to originate loans $ 52,333 $ 35,682 Unused lines and letters of credit 37,963 37,045 Unadvanced funds on construction loans 10,867 9,321 Overdraft lines of credit 9,140 9,189 Commitment under master loan participation agreement 4,554 —

Conversion and Basis of Prese30

Conversion and Basis of Presentation - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Jul. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2016	Jun. 30, 2017	Jul. 01, 2016
Plan Of Conversion [Line Items]
Common stock, shares issued				5,868,726	5,868,544	5,686,750
Share issued, price per share						$ 10
Proceeds from issuance of common stock	$ 56,867,500		$ 67,442,000
Direct cost of stock offering			$ 452,000	$ 2,325,000
Contribution to Randolph Charitable Foundation Inc, shares		181,976
Contribution to Randolph Charitable Foundation Inc, cash		$ 455,000
Contribution to Randolph Charitable Foundation Inc, expense recognized		$ 2,274,700
ESOP [Member]
Plan Of Conversion [Line Items]
Common stock, shares issued						469,498
Loan repayment period	25 years

Acquisition - Additional Inform

Acquisition - Additional Information (Detail) - USD ($)	Jul. 03, 2016	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition [Line Items]
Business acquisition, date			Jul. 1, 2016
Income tax expense (benefit)		$ (254,000)	$ (277,000)	$ 3,000
Pro Forma [Member]
Business Acquisition [Line Items]
Income tax expense (benefit)			$ 0
First Eastern Bankshares Corporation [Member]
Business Acquisition [Line Items]
Cash payment to acquisition	$ 14,100,000

Acquisition - Summary of Unaudi

Acquisition - Summary of Unaudited Pro Forma Financial Information (Detail) - First Eastern Bankshares Corporation [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016
Business Acquisition [Line Items]
Net Interest Income	$ 3,398	$ 6,668
Non-interest Income	5,484	8,714
Net Income	$ 1,246	$ 1,063

Accumulated Other Comprehensi33

Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss and Related Tax Effects (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive income	$ 457	$ 231	$ 492	$ 992
Accumulated other comprehensive loss, net of tax	$ (792)		(792)		$ (1,284)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)			100		(698)
Other comprehensive Loss, Tax effect			(703)		(423)
Total other comprehensive income			(603)		(1,121)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)			(661)		(679)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)			529		573
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gain (loss)			(132)		(106)
Other comprehensive Loss, Tax effect			(57)		(57)
Total other comprehensive income			$ (189)		$ (163)

Securities Available for Sale -

Securities Available for Sale - Schedule of Amortized Cost and Fair Value of Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 67,044	$ 69,335
Gross Unrealized Gains	836	671
Gross Unrealized Losses	(736)	(1,369)
Fair Value	67,144	68,637
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	66,499	68,790
Gross Unrealized Gains	836	671
Gross Unrealized Losses	(728)	(1,362)
Fair Value	66,607	68,099
Debt Securities [Member] | US Government-sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,999	3,999
Gross Unrealized Gains	85	92
Gross Unrealized Losses	(4)	(10)
Fair Value	4,080	4,081
Debt Securities [Member] | Corporate [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,024	3,044
Gross Unrealized Gains	45	54
Gross Unrealized Losses	(6)	(18)
Fair Value	3,063	3,080
Debt Securities [Member] | Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	13,694	13,857
Gross Unrealized Gains	342	254
Gross Unrealized Losses	(3)	(56)
Fair Value	14,033	14,055
Debt Securities [Member] | Residential Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	20,005	21,130
Gross Unrealized Gains	180	172
Gross Unrealized Losses	(344)	(580)
Fair Value	19,841	20,722
Debt Securities [Member] | Commercial Mortgage Backed Securities, U.S. Government-guaranteed [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,882	9,589
Gross Unrealized Gains	53	12
Gross Unrealized Losses	(71)	(144)
Fair Value	8,864	9,457
Debt Securities [Member] | Commercial Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	14,564	14,676
Gross Unrealized Gains	85	56
Gross Unrealized Losses	(300)	(554)
Fair Value	14,349	14,178
Debt Securities [Member] | Collateralized Mortgage Obligations, US Government Guaranteed [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	330	368
Gross Unrealized Gains	4	3
Fair Value	334	371
Debt Securities [Member] | Collateralized Mortgage Obligations, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,001	2,127
Gross Unrealized Gains	42	28
Fair Value	2,043	2,155
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	545	545
Gross Unrealized Losses	(8)	(7)
Fair Value	$ 537	$ 538

Securities Available for Sale35

Securities Available for Sale - Investments Classified by Contractual Maturity Date (Detail) $ in Thousands	Jun. 30, 2017USD ($)
Available-for-sale Securities, Debt Maturities, Amortized Cost
Within 1 year	$ 3,309
After 1 year through 5 years	12,180
After 5 years through 10 years	5,228
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Total	20,717
Mortgage-backed securities	45,782
Available-for-sale Debt Securities, Amortized Cost Basis, Total	66,499
Available-for-sale Securities, Debt Maturities, Fair Value
Within 1 year	3,333
After 1 year through 5 years	12,450
After 5 years through 10 years	5,393
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Fair Value Total	21,176
Mortgage-backed securities	45,431
Available-for-sale Securities, Debt Securities, Fair Value Total	$ 66,607

Securities Available for Sale36

Securities Available for Sale - Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	$ (732)	$ (1,355)
Less Than Twelve Months, Fair Value	31,214	37,311
Over Twelve Months, Gross Unrealized Losses	(4)	(14)
Over Twelve Months, Fair Value	957	1,473
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(724)	(1,348)
Less Than Twelve Months, Fair Value	30,677	36,773
Over Twelve Months, Gross Unrealized Losses	(4)	(14)
Over Twelve Months, Fair Value	957	1,473
Debt Securities [Member] | US Government-sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(4)	(10)
Less Than Twelve Months, Fair Value	1,996	1,990
Debt Securities [Member] | Corporate [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(4)	(14)
Less Than Twelve Months, Fair Value	1,034	519
Over Twelve Months, Gross Unrealized Losses	(2)	(4)
Over Twelve Months, Fair Value	474	996
Debt Securities [Member] | Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(1)	(46)
Less Than Twelve Months, Fair Value	454	3,310
Over Twelve Months, Gross Unrealized Losses	(2)	(10)
Over Twelve Months, Fair Value	483	477
Debt Securities [Member] | Residential Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(344)	(580)
Less Than Twelve Months, Fair Value	14,129	16,261
Debt Securities [Member] | Commercial Mortgage Backed Securities, U.S. Government-guaranteed [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(71)	(144)
Less Than Twelve Months, Fair Value	4,100	5,927
Debt Securities [Member] | Commercial Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(300)	(554)
Less Than Twelve Months, Fair Value	8,964	8,766
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(8)	(7)
Less Than Twelve Months, Fair Value	$ 537	$ 538

Securities Available for Sale37

Securities Available for Sale - Additional Information (Detail)	Jun. 30, 2017Debt_Security
Schedule of Available-for-sale Securities [Line Items]
Number of debt securities with unrealized losses	28
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses debt securities aggregate depreciation percentage	2.30%

Loans and Allowance for Loan 38

Loans and Allowance for Loan Losses - Summary of Loan Portfolio (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 367,209	$ 335,086
Allowance for loan losses	(3,557)	(3,271)
Net deferred loan costs and fees, and purchase premiums	1,341	1,176
Net loans	364,993	332,991
Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	338,816	326,441
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	93,007	88,394
Commercial Real Estate Loans [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	93,007	88,394
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	17,181	2,067
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	11,212	6,578
One-to-Four Family [Member] | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	182,323	179,025
One-to-Four Family [Member] | Residential Real Estate [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	182,323	179,025
Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	38,681	35,393
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	24,805	23,629
Construction [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 24,805	$ 23,629

Loans and Allowance for Loan 39

Loans and Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)TDR	Jun. 30, 2016USD ($)TDR	Dec. 31, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased loan participations originated through super-regional bank	$ 15,400,000		$ 15,400,000
Refinanced student loans purchased	5,000,000		5,000,000
Loans past due 90 days or more	0		0		$ 0
Impaired loans, additional funds committed	0		0
Troubled debt restructuring amount			4,006,000	$ 3,859,000
Changes to allowance for loan losses	0	$ 0	$ 0	0
Minimum past due days for loan rating			90 days
Total loans	367,209,000		$ 367,209,000		335,086,000
Residential Mortgage [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	339,000		339,000		890,000
Residential Mortgage [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,098,000		2,098,000		1,471,000
30 - 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings defaulted over 30 days past due	0	0	0	0
Non Accrual Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring amount			997,000	$ 1,729,000
Home Equity Loans and Lines of Credit [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	29,000		29,000
Home Equity Loans and Lines of Credit [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	370,000		$ 370,000		400,000
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans subject to troubled debt restructurings | TDR			19	18
Loans subject to troubled debt restructurings, amount	4,449,000	4,548,000	$ 4,449,000	$ 4,548,000
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans subject to troubled debt restructurings | TDR			3	5
Loans subject to troubled debt restructurings, amount	553,000	$ 1,010,000	$ 553,000	$ 1,010,000
Total loans	93,007,000		93,007,000		88,394,000
Commercial Real Estate Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 204,000		$ 204,000		$ 208,000

Loans and Allowance for Loan 40

Loans and Allowance for Loan Losses - Summary of Changes in the Allowance for Loan Losses by Portfolio Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 3,437	$ 3,285	$ 3,271	$ 3,239
Provision (credit) for loan losses	100		335	62
Loans charged-off	(32)	(34)	(109)	(60)
Recoveries	52	8	60	18
Ending balance	3,557	3,259	3,557	3,259
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	1,519	1,559	1,410	1,402
Provision (credit) for loan losses	17	(39)	126	118
Ending balance	1,536	1,520	1,536	1,520
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	195	36	37	37
Provision (credit) for loan losses	47		204	(1)
Recoveries	34		35
Ending balance	276	36	276	36
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	156	84	145	53
Provision (credit) for loan losses	64	21	149	69
Loans charged-off	(32)	(34)	(109)	(60)
Recoveries	10	7	13	16
Ending balance	198	78	198	78
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	821	1,054	1,018	1,076
Provision (credit) for loan losses	(9)	(9)	(210)	(32)
Recoveries	8	1	12	2
Ending balance	820	1,046	820	1,046
Second Mortgages and HELOC [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	395	431	436	512
Provision (credit) for loan losses	(57)	13	(98)	(68)
Ending balance	338	444	338	444
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	351	121	225	159
Provision (credit) for loan losses	38	14	164	(24)
Ending balance	$ 389	$ 135	$ 389	$ 135

Loans and Allowance for Loan 41

Loans and Allowance for Loan Losses - Summary of Additional Information Pertaining to the Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for impaired loans	$ 192		$ 200
Allowance for non-impaired loans	3,365		3,071
Total allowance for loan losses	3,557	$ 3,437	3,271	$ 3,259	$ 3,285	$ 3,239
Impaired loans	6,178		5,614
Non-impaired loans	361,031		329,472
Total loans	367,209		335,086
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for impaired loans	14		8
Allowance for non-impaired loans	1,522		1,402
Total allowance for loan losses	1,536	1,519	1,410	1,520	1,559	1,402
Impaired loans	757		832
Non-impaired loans	92,250		87,562
Total loans	93,007		88,394
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for non-impaired loans	276		37
Total allowance for loan losses	276	195	37	36	36	37
Non-impaired loans	17,181		2,067
Total loans	17,181		2,067
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for non-impaired loans	198		145
Total allowance for loan losses	198	156	145	78	84	53
Non-impaired loans	11,212		6,578
Total loans	11,212		6,578
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for impaired loans	177		190
Allowance for non-impaired loans	643		828
Total allowance for loan losses	820	821	1,018	1,046	1,054	1,076
Impaired loans	5,145		4,506
Non-impaired loans	177,178		174,519
Total loans	182,323		179,025
Second Mortgages and HELOC [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for impaired loans	1		2
Allowance for non-impaired loans	337		434
Total allowance for loan losses	338	395	436	444	431	512
Impaired loans	276		276
Non-impaired loans	38,405		35,117
Total loans	38,681		35,393
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for non-impaired loans	389		225
Total allowance for loan losses	389	$ 351	225	$ 135	$ 121	$ 159
Non-impaired loans	24,805		23,629
Total loans	$ 24,805		$ 23,629

Loans and Allowance for Loan 42

Loans and Allowance for Loan Losses - Schedule of Past Due and Non-Accrual Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 847	$ 2,086
Non-accrual Loans	2,236	2,221
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		59
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	643	1,369
Non-accrual Loans	1,960	1,945
Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	204	258
Non-accrual Loans	276	276
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		400
30 - 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	705	1,885
30 - 59 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		59
30 - 59 Days Past Due [Member] | One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	501	1,168
30 - 59 Days Past Due [Member] | Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	204	258
30 - 59 Days Past Due [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		400
60 - 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	142	201
60 - 89 Days Past Due [Member] | One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 142	$ 201

Loans and Allowance for Loan 43

Loans and Allowance for Loan Losses - Summary of Impaired Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	$ 3,086	$ 2,438
Unpaid Principal Balance without a valuation allowance	3,042	2,393
Recorded Investment with a valuation allowance	3,156	3,241
Unpaid Principal Balance with a valuation allowance	3,136	3,221
Related Allowance, Total impaired loans	192	200
Recorded Investment, Total impaired loans	6,242	5,679
Unpaid Principal Balance, Total impaired loans	6,178	5,614
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	251	270
Unpaid Principal Balance without a valuation allowance	252	270
Recorded Investment with a valuation allowance	505	562
Unpaid Principal Balance with a valuation allowance	505	562
Related Allowance, Total impaired loans	14	8
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	2,588	1,922
Unpaid Principal Balance without a valuation allowance	2,543	1,877
Recorded Investment with a valuation allowance	2,621	2,648
Unpaid Principal Balance with a valuation allowance	2,602	2,629
Related Allowance, Total impaired loans	177	190
Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	247	246
Unpaid Principal Balance without a valuation allowance	247	246
Recorded Investment with a valuation allowance	30	31
Unpaid Principal Balance with a valuation allowance	29	30
Related Allowance, Total impaired loans	$ 1	$ 2

Loans and Allowance for Loan 44

Loans and Allowance for Loan Losses - Summary of Additional Information Pertaining to Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 6,010	$ 6,307	$ 5,846	$ 6,499
Interest Income Recognized	64	66	118	123
Cash Basis Interest Recognized	27	17	47	30
Residential Real Estate [Member] | One-to-Four Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,964	4,783	4,782	4,942
Interest Income Recognized	55	48	99	89
Cash Basis Interest Recognized	27	16	46	29
Residential Real Estate [Member] | Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	276	288	276	241
Interest Income Recognized		1	1	1
Cash Basis Interest Recognized		1	1	1
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	770	1,236	788	1,304
Interest Income Recognized	$ 9	$ 17	$ 18	33
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment				$ 12

Loans and Allowance for Loan 45

Loans and Allowance for Loan Losses - Summary of Company's Loans by Risk Rating (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 367,209	$ 335,086
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	93,007	88,394
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	17,181	2,067
Pass [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	92,803	88,186
Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	17,181	2,067
Substandard [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	204	208
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	24,805	23,629
Construction [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 24,805	23,286
Construction [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans		$ 343

Loan Servicing - Additional Inf

Loan Servicing - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Transfers And Servicing [Abstract]
Unpaid principal balance of residential mortgage loans serviced for others	$ 1,097,334,000	$ 1,046,551,000
Increased in valuation allowance of mortgage servicing rights	$ 231,000

Loan Servicing - Summary of Act

Loan Servicing - Summary of Activity Relating to Mortgage Servicing Rights (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Mortgage servicing rights:
Balance at beginning of year	$ 8,910	$ 2,601
Additions through originations	946	439
Amortization	(671)	(213)
Balance at end of period	9,185	2,827
Valuation allowance:
Balance at beginning of year	424	34
Provision (credit)	(231)	25
Balance at end of period	193	59
Amortized cost, net	8,992	2,768	$ 8,486
Fair value	$ 9,014	$ 2,898

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Deferred income tax benefit	$ 280,000	$ 0
Current state tax expense	$ 3,000	$ 3,000

On-Balance Sheet Derivative I49

On-Balance Sheet Derivative Instruments and Hedging Activities - Additional Information (Detail) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Derivative Loan Commitments [Member]
Derivative [Line Items]
Derivative, Notional amount	$ 42,901,000	$ 32,904,000
Forward Loan Sale Commitments [Member]
Derivative [Line Items]
Derivative, Notional amount	21,445,000	18,197,000
Other Assets [Member] | Derivative Loan Commitments [Member]
Derivative [Line Items]
Derivative fair value, Asset	538,000	617,000
Other Assets [Member] | Forward Loan Sale Commitments [Member]
Derivative [Line Items]
Derivative fair value, Asset	69,000	65,000
Other Liabilities [Member] | Forward Loan Sale Commitments [Member]
Derivative [Line Items]
Derivative fair value, Liability	$ 18,000	$ 47,000

Employee Stock Ownership Plan -

Employee Stock Ownership Plan - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2017USD ($)shares	Jun. 30, 2017USD ($)shares
Employee Stock Ownership Plan E S O P Disclosures [Line Items]
Number of allocated shares	18,780	18,780
Annual allocation of shares, expiration year		2,040
Shares committed to be released	4,695	9,390
Fair value of shares under employee stock ownership plan | $	$ 73,000	$ 145,000
Unallocated shares	441,328	441,328
Unallocated shares, value | $	$ 7,017,100	$ 7,017,100
The Randolph Savings Charitable Foundation, Inc. [Member]
Employee Stock Ownership Plan E S O P Disclosures [Line Items]
Sale of share in employee stock ownership plan		469,498
Percentage of stock issued during period shares employee stock ownership plan		8.00%

Earnings (Loss) Per Share - Add

Earnings (Loss) Per Share - Additional Information (Detail) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Earnings Per Share [Abstract]
Potentially dilutive common stock equivalents outstanding		0
Weighted average number of outstanding shares	5,868,709	5,868,717
Weighted Average Number of Shares, Unallocated and uncommitted ESOP shares	443,676	446,023
Weighted average common shares outstanding (basic and diluted)	5,425,033	5,422,694

Fair Value of Assets and Liab52

Fair Value of Assets and Liabilities - Additional information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net gain on sales of mortgage loans	$ 2,520,000	$ 1,058,000	$ 4,558,000	$ 1,739,000
Increased in valuation allowance of mortgage servicing rights			231,000
Liabilities measured at fair value on nonrecurring basis	0		0		$ 0
Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate fair value of loans held for sale	32,000,000		32,000,000
Contractual balance of loans held for sale	31,300,000		31,300,000
Net gain on sales of mortgage loans	$ 703,000		$ 703,000

Fair Value of Assets and Liab53

Fair Value of Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	$ 67,144	$ 68,637
Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	66,607	68,099
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	537	538
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	67,144	68,637
Fair value, Loans held for sale	32,036	30,452
Derivative assets	607	682
Forward loan sale commitments	18	47
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Loans held for sale	32,036	30,452
Forward loan sale commitments	18	47
Fair Value, Measurements, Recurring [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	66,607	68,099
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	537	538
Fair Value, Measurements, Recurring [Member] | Derivative Loan Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	538	617
Fair Value, Measurements, Recurring [Member] | Forward Loan Sale Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	69	65
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Loans held for sale	32,036	30,452
Forward loan sale commitments	18	47
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	66,607	68,099
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	537	538
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Derivative Loan Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	538	617
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Forward Loan Sale Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 69	$ 65

Fair Value of Assets and Liab54

Fair Value of Assets and Liabilities - Schedule of Assets Measured at Fair Value on a Non-Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights, fair value	$ 9,014		$ 2,898
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights, fair value	8,992	$ 8,486
Assets, Fair Value Disclosure	8,992	8,486
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Collateral dependent impaired loans	1,274	518
Assets, Fair Value Disclosure	$ 1,274	$ 518

Fair Value of Assets and Liab55

Fair Value of Assets and Liabilities - Summary of Carrying Values, Estimated Fair Values and Placement in Fair Value Hierarchy of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financial assets:
Securities available for sale	$ 67,144	$ 68,637
Level 2 [Member]
Financial assets:
Certificates of deposit	3,195	3,687
Securities available for sale	67,144	68,637
Loans held for sale	32,036	30,452
Derivative assets	607	682
Financial liabilities:
Deposits	368,285	350,979
FHLBB advances	48,370	38,531
Derivative liabilities	18	47
Level 3 [Member]
Financial assets:
Loans, net	362,000	331,132
Carrying Amount [Member]
Financial assets:
Certificates of deposit	3,185	3,675
Securities available for sale	67,144	68,637
Loans held for sale	32,036	30,452
Loans, net	364,993	332,991
Derivative assets	607	682
Financial liabilities:
Deposits	368,588	351,179
FHLBB advances	48,464	38,667
Derivative liabilities	18	47
Fair Value [Member]
Financial assets:
Certificates of deposit	3,195	3,687
Securities available for sale	67,144	68,637
Loans held for sale	32,036	30,452
Loans, net	362,000	331,132
Derivative assets	607	682
Financial liabilities:
Deposits	368,285	350,979
FHLBB advances	48,370	38,531
Derivative liabilities	$ 18	$ 47

Commitments and Contingencies -

Commitments and Contingencies - Summary of Financial Instruments Outstanding Contract Amounts Represent Credit Risk (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	$ 52,300
Commitments to Originate Loans [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	52,333	$ 35,682
Unused Lines and Letters of Credit [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	37,963	37,045
Unadvanced Funds on Construction Loans [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	10,867	9,321
Overdraft Lines of Credit [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	9,140	$ 9,189
Commitment Under Master Loan Participation Agreement [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	$ 4,554

Commitments and Contingencies57

Commitments and Contingencies - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2017USD ($)
Commitments And Contingencies [Line Items]
Financial instruments with off-balance-sheet risk	$ 52.3
Initial lease term of non-cancelable leases	5 years
Additional period of lease term of non-cancelable leases	5 years
Aggregate future minimum rent commitment	$ 2.5
Braintree, MA [Member]
Commitments And Contingencies [Line Items]
Initial lease term of non-cancelable leases	5 years
Additional period of lease term of non-cancelable leases	5 years
Number of renewal options	2
Loans to Be Sold in the Secondary Mortgage Market
Commitments And Contingencies [Line Items]
Financial instruments with off-balance-sheet risk	$ 42.9
Forward Loan Sale Commitments [Member]
Commitments And Contingencies [Line Items]
Financial instruments with off-balance-sheet risk	$ 30.8

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event [Member] - Residential Mortgage [Member] $ in Millions	Jul. 31, 2017USD ($)
Subsequent Event [Line Items]
Mortgage servicing rights sold to third party	$ 379
Proceeds from sale of mortgage servicing rights, percentage	70.00%
Proceeds from sale of mortgage servicing rights	$ 2.4