Century Bancorp (CNBKA) 10-Q 8 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Trading Symbol	CNBKA
Entity Registrant Name	CENTURY BANCORP INC
Entity Central Index Key	0000812348
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Address, State or Province	MA
Title of 12(b) Security	Class A Common Stock
Security Exchange Name	NASDAQ
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,650,449
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,917,460

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 85,014	$ 89,540
Federal funds sold and interest-bearing deposits in other banks	249,091	252,963
Total cash and cash equivalents	334,105	342,503
Securities available-for-sale, amortized cost $261,939 and $336,751, respectively	261,739	336,759
Securities held-to-maturity, fair value $2,188,465 and $1,991,421, respectively	2,164,135	2,046,647
Federal Home Loan Bank of Boston, stock at cost	14,025	17,974
Equity securities, amortized cost $1,635 and $1,635, respectively	1,672	1,596
Loans, net:
Total loans, net	2,375,661	2,285,578
Less: allowance for loan losses	29,097	28,543
Net loans	2,346,564	2,257,035
Bank premises and equipment	31,520	23,921
Accrued interest receivable	13,275	14,406
Goodwill	2,714	2,714
Other assets	129,432	120,380
Total assets	5,299,181	5,163,935
Deposits:
Demand deposits	797,455	813,478
Savings and NOW deposits	1,759,401	1,707,019
Money market accounts	1,249,923	1,325,888
Time deposits	533,074	560,579
Total deposits	4,339,853	4,406,964
Securities sold under agreements to repurchase	307,235	154,240
Other borrowed funds	209,188	202,378
Subordinated debentures	36,083	36,083
Other liabilities	77,862	63,831
Total liabilities	4,970,221	4,863,496
Stockholders' Equity
Preferred Stock – $1.00 par value; 100,000 shares authorized; no shares issued and outstanding
Additional paid-in capital	12,292	12,292
Retained earnings	328,801	301,488
Stockholders' equity before adjustment of accumulated other comprehensive income (loss)	346,661	319,348
Unrealized losses on securities available-for-sale, net of taxes	(150)	6
Unrealized losses on securities transferred to held-to-maturity, net of taxes	(1,991)	(2,565)
Pension liability, net of taxes	(15,560)	(16,350)
Total accumulated other comprehensive loss, net of taxes	(17,701)	(18,909)
Total stockholders' equity	328,960	300,439
Total liabilities and stockholders' equity	5,299,181	5,163,935
Construction and land development [Member]
Loans, net:
Total loans, net	7,824	13,628
Commercial and industrial [Member]
Loans, net:
Total loans, net	783,950	761,625
Municipal [Member]
Loans, net:
Total loans, net	121,802	97,290
Commercial real estate [Member]
Loans, net:
Total loans, net	765,385	750,362
Residential real estate [Member]
Loans, net:
Total loans, net	364,317	348,250
Consumer and overdrafts [Member]
Loans, net:
Total loans, net	21,748	22,083
Home equity [Member]
Loans, net:
Total loans, net	310,635	292,340
Class A Common Stock [Member]
Stockholders' Equity
Common stock value	3,650	3,608
Total stockholders' equity	3,650	3,608
Class B Common Stock [Member]
Stockholders' Equity
Common stock value	1,918	1,960
Total stockholders' equity	$ 1,918	$ 1,960

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Amortized cost	$ 261,939	$ 336,751
Held-to-maturity securities, fair value	2,188,465	1,991,421
Equity securities, amortized cost	$ 1,635	$ 1,635
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	100,000	100,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A Common Stock [Member]
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	3,650,449	3,608,329
Class B Common Stock [Member]
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	5,000,000	5,000,000
Common stock, shares issued	1,917,460	1,959,580

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest income
Loans	$ 22,117	$ 20,167	$ 65,106	$ 57,613
Securities held-to-maturity	14,623	11,507	43,006	32,930
Securities available-for-sale	2,184	2,500	7,305	6,821
Federal funds sold and interest-bearing deposits in other banks	928	591	3,204	2,239
Total interest income	39,852	34,765	118,621	99,603
Interest expense
Savings and NOW deposits	5,445	2,972	16,788	7,778
Money market accounts	5,050	3,652	15,805	9,039
Time deposits	3,038	2,571	8,724	7,465
Securities sold under agreements to repurchase	697	288	1,572	657
Other borrowed funds and subordinated debentures	1,852	2,078	5,274	5,793
Total interest expense	16,082	11,561	48,163	30,732
Net interest income	23,770	23,204	70,458	68,871
Provision for loan losses	75		700	900
Net interest income after provision for loan losses	23,695	23,204	69,758	67,971
Other operating income
Service charges on deposit accounts	2,310	2,137	6,801	6,268
Lockbox fees	937	892	3,018	2,304
Net gains on sales of securities	53	105	61	302
Gains on sales of mortgage loans	0		154
Other income	986	1,035	3,676	3,210
Total other operating income	4,286	4,169	13,710	12,084
Operating expenses
Salaries and employee benefits	10,670	10,570	32,621	32,331
Occupancy	1,463	1,481	4,686	4,579
Equipment	862	781	2,440	2,355
Other	4,467	4,516	14,170	13,243
Total operating expenses	17,462	17,348	53,917	52,508
Income before income taxes	10,519	10,025	29,551	27,547
Provision for income taxes	435	444	584	1,259
Net income	$ 10,084	$ 9,581	$ 28,967	$ 26,288
Class A Common Stock [Member]
Share data:
Weighted average number of shares outstanding, basic	3,650,449	3,608,329	3,627,076	3,608,129
Weighted average number of shares outstanding, diluted	5,567,909	5,567,909	5,567,909	5,567,909
Basic earnings per share	$ 2.19	$ 2.09	$ 6.30	$ 5.73
Diluted earnings per share	$ 1.81	$ 1.72	$ 5.20	$ 4.72
Class B Common Stock [Member]
Share data:
Weighted average number of shares outstanding, basic	1,917,460	1,959,580	1,940,833	1,959,780
Weighted average number of shares outstanding, diluted	1,917,460	1,959,580	1,940,833	1,959,780
Basic earnings per share	$ 1.09	$ 1.04	$ 3.15	$ 2.86
Diluted earnings per share	$ 1.09	$ 1.04	$ 3.15	$ 2.86

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 10,084	$ 9,581	$ 28,967	$ 26,288
Unrealized gains (losses) on securities:
Unrealized gains (losses) arising during period	113	(88)	(112)	412
Less: reclassification adjustment for gains included in net income	(39)	(76)	(44)	(217)
Total unrealized gains (losses) on securities	74	(164)	(156)	195
Accretion of net unrealized losses transferred	155	238	574	872
Defined benefit pension plans:
Amortization of prior service cost and loss included in net periodic benefit cost	263	292	790	877
Other comprehensive income	492	366	1,208	1,944
Comprehensive income	$ 10,576	$ 9,947	$ 30,175	$ 28,232

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Class A Common Stock [Member]	Class B Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Class A Common Stock [Member]	Retained Earnings [Member]Class B Common Stock [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning balance at Dec. 31, 2017	$ 260,297	$ 3,606	$ 1,962	$ 12,292	$ 263,666			$ (21,229)
Net income	26,288				26,288
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	195							195
Accretion of net unrealized losses transferred during the period, net of taxes	872							872
Pension liability adjustment, net of taxes	877							877
Adoption of ASU 2018-2, Income Statement-Reporting Comprehensive Income (Topic 220)-Reclassification of Certain Tax Effects from AOCI					3,783			(3,783)
Adoption of ASU 2016-1, Financial Instruments-Overall (Subtopic 825-10) Recognition and Measurement of Financial Assets and Financial Liabilities					29			(29)
Conversion of Class B Common Stock to Class A Common Stock		2	(2)
Cash dividends		(1,299)	(353)			$ (1,299)	$ (353)
Ending balance at Sep. 30, 2018	286,877	3,608	1,960	12,292	292,114			(23,097)
Beginning balance at Jun. 30, 2018	277,481	3,608	1,960	12,292	283,084			(23,463)
Net income	9,581				9,581
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	(164)							(164)
Accretion of net unrealized losses transferred during the period, net of taxes	238							238
Pension liability adjustment, net of taxes	292							292
Cash dividends		(432)	(119)			(432)	(119)
Ending balance at Sep. 30, 2018	286,877	3,608	1,960	12,292	292,114			(23,097)
Beginning balance at Dec. 31, 2018	300,439	3,608	1,960	12,292	301,488			(18,909)
Net income	28,967				28,967
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	(156)							(156)
Accretion of net unrealized losses transferred during the period, net of taxes	574							574
Pension liability adjustment, net of taxes	790							790
Conversion of Class B Common Stock to Class A Common Stock		42	(42)
Cash dividends		(1,304)	(350)			(1,304)	(350)
Ending balance at Sep. 30, 2019	328,960	3,650	1,918	12,292	328,801			(17,701)
Beginning balance at Jun. 30, 2019	318,937	3,620	1,948	12,292	319,270			(18,193)
Net income	10,084			0	10,084			0
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	74							74
Accretion of net unrealized losses transferred during the period, net of taxes	155							155
Pension liability adjustment, net of taxes	263							263
Conversion of Class B Common Stock to Class A Common Stock		30	(30)
Cash dividends		(438)	(115)			$ (438)	$ (115)
Ending balance at Sep. 30, 2019	$ 328,960	$ 3,650	$ 1,918	$ 12,292	$ 328,801			$ (17,701)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Unrealized holding gains arising during period, taxes	$ 23	$ 30	$ 52	$ 39
Realized net gains	53		61	302
Accretion of net unrealized losses transferred during the period, taxes	54	85	205	314
Pension liability adjustment, taxes	$ 103	$ 114	$ 309	$ 342
Class A Common Stock [Member]
Conversion of Class B Common Stock to Class A Common Stock, shares	30,000		42,120	2,500
Cash dividends, per share	$ 0.12	$ 0.12	$ 0.36	$ 0.36
Class B Common Stock [Member]
Conversion of Class B Common Stock to Class A Common Stock, shares	30,000		42,120	2,500
Cash dividends, per share	$ 0.06	$ 0.06	$ 0.18	$ 0.18

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 28,967	$ 26,288
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Gain on sales of mortgage loans	(154)
Net gains on sales of securities	(61)	(302)
Net (gain) loss on equity securities	(76)	47
Provision for loan losses	700	900
Deferred income taxes	(593)	(1,270)
Net depreciation and amortization	(1,693)	1,116
Decrease (increase) in accrued interest receivable	1,131	(1,699)
(Increase) decrease in other assets	(1,037)	1,542
Increase in other liabilities	2,029	4,825
Net cash provided by operating activities	29,213	31,447
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from redemptions of Federal Home Loan Bank of Boston stock	13,801	13,619
Purchase of Federal Home Loan Bank of Boston stock	(9,852)	(14,583)
Proceeds from calls/maturities of securities available-for-sale	115,574	111,922
Proceeds from sales of securities available-for-sale	16,285	27,517
Purchase of securities available-for-sale	(57,005)	(108,871)
Proceeds from calls/maturities of securities held-to-maturity	313,358	187,009
Purchase of securities held-to-maturity	(427,124)	(358,824)
Proceeds from sales of securities held-to-maturity	1,194
Proceeds from life insurance policies	5,124	375
Net increase in loans	(98,915)	(83,967)
Proceeds from sales of portfolio loans	8,871
Capital expenditures	(9,962)	(2,900)
Net cash used in investing activities	(128,651)	(228,703)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net decrease in time deposits	(27,505)	(45,475)
Net decrease (increase) in demand, savings, money market and NOW deposits	(39,606)	92,915
Cash dividends	(1,654)	(1,652)
Net increase (decrease) in securities sold under agreements to repurchase	152,995	(18,500)
Net increase in other borrowed funds	6,810	24,828
Net cash provided by financing activities	91,040	52,116
Net decrease in cash and cash equivalents	(8,398)	(145,140)
Cash and cash equivalents at beginning of period	342,503	356,430
Cash and cash equivalents at end of period	334,105	211,290
Cash paid (received) during the period for:
Interest	48,127	30,680
Income tax refunds	(6,604)
Income taxes		590
Change in unrealized gains (losses) on securities available-for-sale, net of taxes	(156)	195
Change in unrealized losses on securities transferred to held-to-maturity, net of taxes	574	872
Pension liability adjustment, net of taxes	$ 790	877
Change in due to (from) to broker		$ 897

Basis of Financial Statement Pr

Basis of Financial Statement Presentation	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial Statement Presentation	Note 1. Basis of Financial Statement Presentation The consolidated financial statements include the accounts of Century Bancorp, Inc. (the “Company”) and its wholly owned subsidiary, Century Bank and Trust Company (the “Bank”). The consolidated financial statements also include the accounts of the Bank’s wholly owned subsidiaries, Century Subsidiary Investments, Inc. (“CSII”), Century Subsidiary Investments, Inc. II (“CSII II”), Century Subsidiary Investments, Inc. III (“CSII III”) and Century Financial Services Inc. (“CFSI”). CSII, CSII II, and CSII III are engaged in buying, selling and holding investment securities. CFSI has the power to engage in financial agency, securities brokerage, and investment and financial advisory services and related securities credit. The Company also owns 100% of Century Bancorp Capital Trust II (“CBCT II”). The entity is an unconsolidated subsidiary of the Company. All significant intercompany accounts and transactions have been eliminated in consolidation. The Company provides a full range of banking services to individual, business and municipal customers in Massachusetts, New Hampshire, Rhode Island, Connecticut, and New York. As a bank holding company, the Company is subject to the regulation and supervision of the Federal Reserve Board. The Bank, a state chartered financial institution, is subject to supervision and regulation by applicable state and federal banking agencies, including the Federal Reserve Board, the Federal Deposit Insurance Corporation (the “FDIC”) and the Commonwealth of Massachusetts Commissioner of Banks. The Bank is also subject to various requirements and restrictions under federal and state law, including requirements to maintain reserves against deposits, restrictions on the types and amounts of loans that may be granted and the interest that may be charged thereon, and limitations on the types of investments that may be made and the types of services that may be offered. Various consumer laws and regulations also affect the operations of the Bank. In addition to the impact of regulation, commercial banks are affected significantly by the actions of the Federal Reserve Board as it attempts to control the money supply and credit availability in order to influence the economy. All aspects of the Company’s business are highly competitive. The Company faces aggressive competition from other lending institutions and from numerous other providers of financial services. The Company has one reportable operating segment. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America and general practices within the banking industry. In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and revenues and expenses for the period. Actual results could differ from those estimates. The Company’s quarterly report on Form 10-Q should be read in conjunction with the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018, as filed with the Securities and Exchange Commission. Material estimates that are susceptible to change in the near term relate to the allowance for loan losses. Management believes that the allowance for loan losses is adequate based on a qualitative risk factors for each category and general economic factors. While management uses available information to recognize loan losses, future additions to the allowance for loan losses may be necessary based on changes in economic conditions. In addition, regulatory agencies periodically review the Company’s allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance for loan losses based on their judgments about information available to them at the time of their examination. Certain reclassifications are made to prior-year amounts whenever necessary to conform with the current-year presentation.

Recent Accounting Developments

Recent Accounting Developments	9 Months Ended
	Sep. 30, 2019
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Developments	Note 2. Recent Accounting Developments Recently Adopted Accounting Standards Updates In July 2017, FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815): I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interest with a Scope Exception. For public entities, this ASU is effective for annual reporting periods beginning after December 15, 2018. The effect of this update did not have a material impact on the Company’s consolidated financial position. In March 2017, the FASB issued ASU 2017-08, Receivables — Nonrefundable Fees and Other Costs (Subtopic 310-20) Premium Amortization of Purchased Callable Debt. The FASB is issuing this ASU to amend the amortization period for certain purchased callable debt securities held at a premium. The FASB is shortening the amortization period for the premium to the earliest call date. Under current generally accepted accounting principles (GAAP), entities generally amortize the premium as an adjustment of yield over the contractual life of the instrument. For public business entities, the amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The effect of this update did not have a material impact on the Company’s consolidated financial position. In February 2016, the FASB issued ASU 2016-02, Leases. This ASU required lessees to put most leases on their balance sheet but recognize expenses on their income statements in a manner similar to today’s accounting. This ASU also eliminated today’s real estate-specific provisions for all companies. For lessors, this ASU modified the classification criteria and the accounting for sales-type and direct financing leases. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods therein. The Company also reviewed contracts to determine if they contain embedded leases. The Company’s balance sheet impact was $15.1 million as of January 1, 2019. This amount was recorded as a right of use asset , included in other assets, with a corresponding lease liability , included in other liabilities . In July 2018, ASU 2018-10, “Codification Improvements to Topic 842, Leases” (“ASU 2018-10”) was issued to provide more detailed guidance and additional clarification for implementing ASU 2016-02. Also in July 2018, ASU 2018-11, “Targeted Improvements” (“ASU 2018-11”) was issued and allows for an optional transition method in which the provisions of Topic 842 would be applied upon the adoption date and would not have to be retroactively applied to the earliest reporting period presented in the consolidated financial statements.” The Company used this optional transition method for the adoption of Topic 842. Accounting Standards Issued but not yet Adopted The following list identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU was issued to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this ASU replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company is in the process of implementing this ASU, has purchased a software solution and is capturing information needed to implement this ASU. As part of the FASB ASC 326 implementation process the company is using two models: a rating migration model and a probability of default model. The probability of default model is based primarily on four components: loss history, product lifecycle, behavioral attributes and the economic environment. The ratings migration model is designed to estimate loss reserves according to the CECL standard for rated loans or similar instruments. The model structure follows a grade migration approach, where the default rate is based on the probability of each grade transition which is modeled using historical data. The Company has started to input information into the models, and is running the software program and comparing to existing results. In addition, the Company has also begun developing accounting policies, as well as designing and implementing new internal controls relevant to the updated methodologies and models. The Company has not determined the dollar impact as of September 30, 2019. The securities held-to-maturity 2016-13 Since ASU 2016-13, the FASB has issued amendments intended on improving the clarification of the amendment, ASU 2018-19 Codification Improvements to Topic 326, Financial Instruments – Credit Losses and ASU 2019-04 Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging. The amendment in ASU 2018-19 was issued in November 2018 and was intended to clarify that receivables arising from operating leases are not within the scope of Subtopic 326-20. Instead, impairment of receivables arising from operating leases should be accounted for in accordance with Topic 842, Leases. The amendment in ASU 2019-04 was issued in April 2019 and was intended to clarify stakeholders’ specific issues about certain aspects of the amendments in ASU 2016-13. ASU 2019-05 Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief was also issued in May 2019. This ASU provides entities the option to irrevocably elect the fair value option for certain financial assets previously measured at amortized costs basis. The fair value option election does not apply to held-to-maturity debt securities. An entity that elects the fair value option should subsequently apply the guidance in Subtopics 820-10, Fair Value Measurement—Overall. The amendments in this ASU should be applied on a modified-retrospective basis by means of a cumulative-effect adjustment to the opening balance of retained earnings balance in the statement of financial position as of the date that an entity early adopted the amendments in ASU 2016-13. In August 2018, FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force) The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). This ASU is effective for annual reporting periods beginning after December 15, 2019. The effect of this update is not expected to have a material impact on the Company’s consolidated financial position. In August 2018, FASB issued ASU 2018-14, 715-20): In August 2018, FASB issued ASU 2018-13, In January 2017, the FASB issued ASU 2017-04, Intangibles — Goodwill and Other (Topic 350). This ASU was issued to simplify the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. For public entities, this ASU is effective for the fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted and application should be on a prospective basis. The effect of this update is not expected to have a material impact on the Company’s consolidated financial position. Securities and Exchange Commission (SEC) ruling: In August 2018, the SEC issued a final rule that amends certain of the Commission’s disclosure requirements “that have become redundant, duplicative, overlapping, outdated, or superseded, in light of other Commission disclosure requirements, U.S. GAAP, or changes in the information environment.” The financial reporting implications of the final rule’s amendments may vary by company, but the changes are generally expected to reduce or eliminate some of an SEC registrant’s disclosure requirements. In limited circumstances, however, the amendments may expand those requirements, including those related to interim disclosures about changes in stockholders’ equity. Under the requirements, registrants must now analyze changes in stockholders’ equity, in the form of a reconciliation, for “the current and comparative year-to-date periods, with subtotals for each interim period.” Beginning with its March 31, 2019 filing, the Company included a reconciliation for the current quarter and year-to-date interim periods as well as the comparative periods of the prior years (i.e., a reconciliation covering each period for which an income statement is presented).

Securities Available-for-Sale

Securities Available-for-Sale	9 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Securities Available-for-Sale	Note 3. Securities Available-for-Sale September 30, 2019 December 31, 2018 Amortized Gross Gross Fair Amortized Gross Gross Fair (in thousands) U.S. Treasury $ — $ — $ — $ — $ 2,000 $ — $ 8 $ 1,992 U.S. Government Sponsored Enterprises — — — — 3,946 — 31 3,915 SBA Backed Securities 58,714 51 101 58,664 70,477 1 284 70,194 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 170,532 189 439 170,282 162,604 536 250 162,890 Privately Issued Residential Mortgage-Backed Securities 574 6 1 579 679 3 10 672 Obligations Issued by States and Political Subdivisions 28,519 57 — 28,576 93,445 58 — 93,503 Other Debt Securities 3,600 64 26 3,638 3,600 37 44 3,593 Total $ 261,939 $ 367 $ 567 $ 261,739 $ 336,751 $ 635 $ 627 $ 336,759 Included in SBA Backed Securities, U.S. Government Sponsored Enterprise Securities and U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities are securities at fair value pledged to secure public deposits and repurchase agreements amounting to $196,356,000 and $197,304,000 at September 30, 2019 Debt securities of U.S. Government Sponsored Enterprises and U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities primarily refer to debt securities of Fannie Mae and Freddie Mac. The following table shows the maturity distribution of the Company’s securities available-for-sale at September 30, 2019. Amortized Fair (in thousands) Within one year $ 26,187 $ 26,184 After one but within five years 134,881 134,811 After five but within ten years 85,551 85,378 More than 10 years 15,320 15,366 Total $ 261,939 $ 261,739 The weighted average remaining life of investment securities available-for-sale at September 30, 2019 was 5.1 years. The contractual maturities, which were used in the table above, of mortgage-backed securities, will differ from the actual maturities, due to the ability of the issuers to prepay underlying obligations. Also $234,949,000 of the securities are floating rate or adjustable rate and reprice prior to maturity. As of September 30, 2019 and December 31, 2018, management concluded that the unrealized losses of its investment securities are temporary in nature since they are not related to the underlying credit quality of the issuers, and the Company does not intend to sell these debt securities and it is not more likely than not that it will be required to sell these debt securities before the anticipated recovery of its remaining amortized cost. In making its other-than-temporary impairment evaluation, the Company considered that the principal and interest on these securities are from issuers that are investment grade. The unrealized loss on SBA Backed Securities, U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities related primarily to interest rates and not credit quality, and because the Company has the ability and intent to hold these investments until recovery of fair value, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired at September 30, 2019 or December 31, 2018. In evaluating the underlying credit quality of a security, management considers several factors such as the credit rating of the obligor and the issuer, if applicable. Internal reviews of issuer financial statements are performed as deemed necessary. In the case of privately issued mortgage-backed securities, the performance of the underlying loans is analyzed as deemed necessary to determine the estimated future cash flows of the securities. Factors considered include the level of subordination, current and estimated future default rates, current and estimated prepayment rates, estimated loss severity rates, geographic concentrations and origination dates of underlying loans. The following table shows the temporarily impaired securities of the Company’s available-for-sale portfolio at September 30, 2019. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for less than 12 months and a continuous loss position for 12 months or longer. There are 24 and 18 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 134 holdings at September 30, 2019. September 30, 2019 Less than 12 months 12 months or longer Total Temporarily Impaired Investments Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ — $ — $ — $ — $ — $ — U.S. Government Sponsored Enterprises — — — — — — SBA Backed Securities 11,133 11 24,944 90 36,077 101 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 81,305 264 27,872 175 109,177 439 Privately Issued Residential Mortgage-Backed Securities — — 282 1 282 1 Obligations Issued by States and Political Subdivisions — — — — — — Other Debt Securities 800 1 475 25 1,275 26 Total temporarily impaired securities $ 93,238 $ 276 $ 53,573 $ 291 $ 146,811 $ 567 The following table shows the temporarily impaired securities of the Company’s available-for-sale portfolio at December 31, 2018. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for less than 12 months and a continuous loss position for 12 months or longer. There are 10 and 30 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 190 holdings at December 31, 2018. December 31, 2018 Less than 12 months 12 months or longer Total Temporarily Impaired Investments Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ — $ — $ 1,992 $ 8 $ 1,992 $ 8 U.S. Government Sponsored Enterprises 3,914 31 — — 3,914 31 SBA Backed Securities 17,950 28 44,323 256 62,273 284 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 19,244 21 45,782 229 65,026 250 Privately Issued Residential Mortgage-Backed Securities — — 495 10 495 10 Obligations Issued by States and Political Subdivisions — — — — — — Other Debt Securities — — 455 44 455 44 Total temporarily impaired securities $ 41,108 $ 80 $ 93,047 $ 547 $ 134,155 $ 627

Investment Securities Held-to-M

Investment Securities Held-to-Maturity	9 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Investment Securities Held-to-Maturity	Note 4. Investment Securities Held-to-Maturity September 30, 2019 December 31, 2018 Amortized Gross Gross Losses Estimated Amortized Gross Gross Estimated (in thousands) U.S. Treasury $ — $ — $ — $ — $ 9,960 $ — $ 2 $ 9,958 U.S. Government Sponsored Enterprises 121,516 653 67 122,102 234,228 336 803 233,761 SBA Backed Securities 47,126 452 66 47,512 52,051 — 2,065 49,986 U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities 1,995,493 29,911 6,553 2,018,851 1,750,408 2,324 55,016 1,697,716 Total $ 2,164,135 $ 31,016 $ 6,686 $ 2,188,465 $ 2,046,647 $ 2,660 $ 57,886 $ 1,991,421 Included in U.S. Government and Agency Securities are securities pledged to secure public deposits and repurchase agreements at fair value amounting to $1,692,033,000 and $1,441,059,000 at September 30, 2019 and December 31, 2018, respectively. Also included are securities pledged for borrowing at the Federal Home Loan Bank of Boston at fair value amounting to $427,425,000 and $291,190,000 at September 30, 2019 and December 31, 2018, respectively. The Company realized gross gains of $48,000 from the proceeds of $1,194,000 from the sales of held-to-maturity securities for the nine months ended September 30, 2019. The sales of securities held-to-maturity relate to certain mortgage backed securities for which the company has previously collected a substantial portion of its principal investment. There were no sales of held-to-maturity securities for the nine months ended September 30, 2018. At September 30, 2019 and December 31, 2018, all mortgage-backed securities are obligations of U.S. Government Agencies and Government Sponsored Enterprises. Debt securities of U.S. Government Sponsored Enterprises and U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities primarily refer to debt securities of Fannie Mae and Freddie Mac. The following table shows the maturity distribution of the Company’s securities held-to-maturity at September 30, 2019. Amortized Fair (in thousands) Within one year $ 70,980 $ 71,260 After one but within five years 1,809,564 1,829,087 After five but within ten years 271,068 275,192 More than ten years 12,523 12,926 Total $ 2,164,135 $ 2,188,465 The weighted average remaining life of investment securities held-to-maturity at September 30, 2019 was 3.6 years. Included in the weighted average remaining life calculation at September 30, 2019 were $66,196,000 of U.S. Government Sponsored Enterprises obligations that are callable at the discretion of the issuer. The contractual maturities, which were used in the table above, of mortgage-backed securities, will differ from the actual maturities, due to the ability of the issuers to prepay underlying obligations. Also $111,000 of the securities are floating rate or adjustable rate and reprice prior to maturity. As of September 30, 2019 and December 31, 2018, management concluded that the unrealized losses of its investment securities are temporary in nature since they are not related to the underlying credit quality of the issuers, and the Company does not intend to sell these debt securities and it is not more likely than not that it will be required to sell these debt securities before the anticipated recovery of their remaining amortized costs. In making its other-than-temporary impairment evaluation, the Company considered the fact that the principal and interest on these securities are from issuers that are investment grade. The unrealized loss on U.S. Government Sponsored Enterprises, SBA Backed Securities, and U.S. Government Sponsored Enterprises Mortgage-Backed Securities related primarily to interest rates and not credit quality, and because the Company does not intend to sell any of these securities and it is not more likely than not that it will be required to sell these securities before the anticipated recovery of the remaining amortized cost, the Company does not consider these investments to be other-than-temporarily impaired at September 30, 2019 or December 31, 2018. In evaluating the underlying credit quality of a security, management considers several factors such as the credit rating of the obligor and the issuer, if applicable. Internal reviews of issuer financial statements are performed as deemed necessary. The following table shows the temporarily impaired securities of the Company’s held-to-maturity portfolio September 30, 2019. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for 12 months or less and a continuous loss position for 12 months or longer. There are 44 and 112 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 505 holdings at September 30, 2019. September 30, 2019 Less Than 12 Months 12 Months or Longer Total Temporarily Impaired Investments Fair Value Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ — $ — $ — $ — $ — $ — U.S. Government Sponsored Enterprises 9,976 22 9,954 45 19,930 67 SBA Backed Securities 13,673 66 — — 13,673 66 U.S. Government Agency and Sponsored Enterprise Mortgage- Backed Securities 163,889 816 430,714 5,737 594,603 6,553 Total temporarily impaired securities $ 187,538 $ 904 $ 440,668 $ 5,782 $ 628,206 $ 6,686 The following table shows the temporarily impaired securities of the Company’s held-to-maturity portfolio at December 31, 2018. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for less than 12 months and a continuous loss position for 12 months or longer. There are 56 and 315 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 475 holdings at December 31, 2018. December 31, 2018 Less Than 12 Months 12 Months or Longer Total Temporarily Impaired Investments Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ 9,958 $ 2 $ — $ — $ 9,958 $ 2 U.S. Government Sponsored Enterprises 9,849 42 69,499 761 79,348 803 SBA Backed Securities — — 49,987 2,065 49,987 2,065 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 188,125 2,032 1,249,689 52,984 1,437,814 55,016 Total temporarily impaired securities $ 207,932 $ 2,076 $ 1,369,175 $ 55,810 $ 1,577,107 $ 57,886

Allowance for Loan Losses

Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Allowance for Loan Losses	Note 5. Allowance for Loan Losses The Company maintains an allowance for loan losses in an amount determined by management on the basis of the character of the loans, loan performance, financial condition of borrowers, the value of collateral securing loans and other relevant factors. The following table summarizes the changes in the Company’s allowance for loan losses for the periods indicated. Three months ended Nine months ended 2019 2018 2019 2018 (in thousands) Allowance for loan losses, beginning of period $ 29,070 $ 27,144 $ 28,543 $ 26,255 Loans charged off (118 ) (89 ) (336 ) (247 ) Recoveries on loans previously charged-off 70 1,490 190 1,637 Net recoveries (charge-offs) (48 ) 1,401 (146 ) 1,390 Provision charged to expense 75 — 700 900 Allowance for loan losses, end of period $ 29,097 $ 28,545 $ 29,097 $ 28,545 Further information pertaining to the allowance for loan losses for the three months ending September 30, 2019 is as Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at June 30, 2019 $ 1,052 $ 11,338 $ 1,832 $ 10,848 $ 2,210 $ 380 $ 1,120 $ 290 $ 29,070 Charge-offs — (57 ) — — — (61 ) — — (118 ) Recoveries — 23 — — — 47 — — 70 Provision (752 ) 9 751 53 (24 ) (84 ) (33 ) 155 75 Ending balance at September 30, 2019 $ 300 $ 11,313 $ 2,583 $ 10,901 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,097 Amount of allowance for loan losses loans deemed to be impaired $ — $ 2 $ — $ 86 $ — $ — $ — $ — $ 88 Amount of allowance for loan losses for loans not deemed to be impaired $ 300 $ 11,311 $ 2,583 $ 10,815 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,009 Loans: Ending balance $ 7,824 $ 783,950 $ 121,802 $ 765,385 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,375,661 Loans deemed to be impaired $ — $ 203 $ — $ 2,373 $ — $ — $ — $ — $ 2,576 Loans not deemed to be impaired $ 7,824 $ 783,747 $ 121,802 $ 763,012 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,373,085 Further information pertaining to the allowance for loan losses for the nine months ending September 30, 2019 is as Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at December 31, 2018 $ 1,092 $ 10,998 $ 1,838 $ 10,663 $ 2,190 $ 365 $ 1,111 $ 286 $ 28,543 Charge-offs — (108 ) — — — (228 ) — — (336 ) Recoveries — 49 — — — 141 — — 190 Provision (792 ) 374 745 238 (4 ) 4 (24 ) 159 700 Ending balance at September 30, 2019 $ 300 $ 11,313 $ 2,583 $ 10,901 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,097 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 2 $ — $ 86 $ — $ — $ — $ — $ 88 Amount of allowance for loan losses for loans not deemed to be impaired $ 300 $ 11,311 $ 2,583 $ 10,815 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,009 Loans: Ending balance $ 7,824 $ 783,950 $ 121,802 $ 765,385 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,375,661 Loans deemed to be impaired $ — $ 203 $ — $ 2,373 $ — $ — $ — $ — $ 2,576 Loans not deemed to be impaired $ 7,824 $ 783,747 $ 121,802 $ 763,012 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,373,085 During the nine months ending September 30, 2019, the Company’s provision was primarily attributable to an increase in municipal, Commercial and industrial, and commercial real estate balances offset, somewhat, by a decrease in construction and land development balances. During the three months ending September 30, 201 9 Overall there were improvements in historical loss rates. Further information pertaining to the allowance for loan losses for the three months ending September 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at June 30, 2018 $ 633 $ 10,384 $ 1,704 $ 10,209 $ 2,493 $ 336 $ 1,078 $ 307 $ 27,144 Charge-offs — (11 ) — — — (78 ) — — (89 ) Recoveries 1,432 16 — — — 42 — — 1,490 Provision (1,155 ) 895 84 415 (182 ) 32 (28 ) (61 ) — Ending balance at September 30, 2018 $ 910 $ 11,284 $ 1,788 $ 10,624 $ 2,311 $ 332 $ 1,050 $ 246 $ 28,545 Amount of allowance for loan losses $ — $ 93 $ — $ 95 $ 350 $ — $ — $ — $ 538 Amount of allowance for loan losses $ 910 $ 11,191 $ 1,788 $ 10,529 $ 1,961 $ 332 $ 1,050 $ 246 $ 28,007 Loans: Ending balance $ 12,434 $ 783,960 $ 94,532 $ 730,265 $ 335,114 $ 21,216 $ 283,818 $ — $ 2,261,339 Loans deemed to be impaired $ — $ 660 $ — $ 2,680 $ 2,675 $ — $ — $ — $ 6,015 Loans not deemed to be impaired $ 12,434 $ 783,300 $ 94,532 $ 727,585 $ 332,439 $ 21,216 $ 283,818 $ — $ 2,255,324 Further information pertaining to the allowance for loan losses for the nine months ending September 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at December 31, 2 017 $ 1,645 $ 9,651 $ 1,720 $ 9,728 $ 1,873 $ 373 $ 989 $ 276 $ 26,255 Charge-offs — (16 ) — — — (231 ) — — (247 ) Recoveries 1,432 49 — — — 156 — — 1,637 Provision (2,167 ) 1,600 68 896 438 34 61 (30 ) 900 Ending balance at September 30, 2018 $ 910 $ 11,284 $ 1,788 $ 10,624 $ 2,311 $ 332 $ 1,050 $ 246 $ 28,545 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 93 $ — $ 95 $ 350 $ — $ — $ — $ 538 Amount of allowance for loan losses for loans not deemed to be impaired $ 910 $ 11,191 $ 1,788 $ 10,529 $ 1,961 $ 332 $ 1,050 $ 246 $ 28,007 Loans: Ending balance $ 12,434 $ 783,960 $ 94,532 $ 730,265 $ 335,114 $ 21,216 $ 283,818 $ — $ 2,261,339 Loans deemed to be impaired $ — $ 660 $ — $ 2,680 $ 2,675 $ — $ — $ — $ 6,015 Loans not deemed to be impaired $ 12,434 $ 783,300 $ 94,532 $ 727,585 $ 332,439 $ 21,216 $ 283,818 $ — $ 2,255,324 During the nine months ending September 30, 2018, the Company’s provision was primarily attributable to an increase in residential real estate balances and increased qualitative allocations for commercial and industrial and commercial real estate loans, offset, somewhat by the recovery of a construction loan previously charged-off and a decrease in construction balances. During the three months ending September 30, 2018, the Company did not require a provision mainly as a result of recoveries of a construction loan previously charged-off and a decrease in construction loan balances offset by increased qualitative allocations for commercial and industrial and commercial real estate loans. The Company monitors the outlook for the industries in which our borrowers operate. Healthcare and higher education are two of the primary industries. In particular the Company utilizes outlooks and forecasts from various sources. Overall a general weakening in the outlook was noted resulting in a general increase in the general economic factors. The Company also monitors the volatility of the losses within the historical data. The Company utilizes a six grade internal loan rating system for commercial real estate, construction and commercial loans as follows: Loans rated 1-3 (Pass): Loans in this category are considered “pass” rated loans with low to average risk. Loans rated 4 (Monitor): These loans represent classified loans that management is closely monitoring for credit quality. These loans have had or may have minor credit quality deterioration as of September 30, 2019 and December 31, 2018. Loans rated 5 (Substandard): Substandard loans represent classified loans that management is closely monitoring for credit quality. These loans have had more significant credit quality deterioration as of September 30, 2019 and December 31, 2018. Loans rated 6 (Doubtful): Doubtful loans represent classified loans that management is closely monitoring for credit quality. These loans had more significant credit quality deterioration as of September 30, 2019 and December 31, 2018 and full collectability is Impaired: Impaired loans represent classified loans that management is closely monitoring for credit quality. A loan is classified as impaired when it is probable that the Company will be unable to collect all amounts due. The following table presents the Company’s loans by risk rating at September 30, 2019. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 (Pass) $ 7,824 $ 779,722 $ 121,802 $ 738,459 4 (Monitor) — 4,025 — 24,553 5 (Substandard) — — — — 6 (Doubtful) — — — — Impaired — 203 — 2,373 Total $ 7,824 $ 783,950 $ 121,802 $ 765,385 The following table presents the Company’s loans by risk rating at December 31, 2018. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 (Pass) $ 13,628 $ 757,089 $ 97,290 $ 723,170 4 (Monitor) — 4,135 — 24,542 5 (Substandard) — — — — 6 (Doubtful) — — — — Impaired — 401 — 2,650 Total $ 13,628 $ 761,625 $ 97,290 $ 750,362 Credit ratings issued by national organizations were utilized as credit quality indicators as presented in the following table at September 30, 2019 and are included within the total loan portfolio. Commercial Municipal Commercial Total (in thousands) Credit Rating: Aaa – Aa3 $ 497,124 $ 54,495 $ 40,759 $ 592,378 A1 – A3 187,970 7,479 148,735 344,184 Baa1 – Baa3 — 51,133 122,288 173,421 Ba2 — 5,895 — 5,895 Total $ 685,094 $ 119,002 $ 311,782 $ 1,115,878 Credit ratings issued by national organizations were utilized as credit quality indicators as presented in the following table at December 31, 2018. Commercial Municipal Commercial Total (in thousands) Credit Rating: Aaa – Aa3 $ 491,247 $ 54,105 $ 42,790 $ 588,142 A1 – A3 172,472 7,605 151,381 331,458 Baa1 – Baa3 — 26,970 118,197 145,167 Ba2 — 6,810 — 6,810 Total $ 663,719 $ 95,490 $ 312,368 $ 1,071,577 The Company utilized payment performance as credit quality indicators for the loan types listed below. The indicators are depicted in the table “aging of past due loans,” below. Further information pertaining to the allowance for loan losses at September 30, 2019 follows: Accruing 30-89 Days Non Accruing Total Current Total (in thousands) Construction and land development $ — $ — $ — $ — $ 7,824 $ 7,824 Commercial and industrial 108 19 — 127 783,823 783,950 Municipal — — — — 121,802 121,802 Commercial real estate 155 167 — 322 765,063 765,385 Residential real estate 1,129 334 — 1,463 362,854 364,317 Consumer and overdrafts 15 — — 15 21,733 21,748 Home equity 1,050 546 — 1,596 309,039 310,635 Total $ 2,457 $ 1,066 $ — $ 3,523 $ 2,372,138 $ 2,375,661 Further information pertaining to the allowance for loan losses at December 31, 2018 follows: Accruing 30-89 Days Non Accruing Total Current Total (in thousands) Construction and land development $ — $ — $ — $ — $ 13,628 $ 13,628 Commercial and industrial 187 115 — 302 761,323 761,625 Municipal — — — — 97,290 97,290 Commercial real estate 774 190 — 964 749,398 750,362 Residential real estate 2,554 569 — 3,123 345,127 348,250 Consumer and overdrafts 24 14 — 38 22,045 22,083 Home equity 1,108 425 — 1,533 290,807 292,340 Total $ 4,647 $ 1,313 $ — $ 5,960 $ 2,279,618 $ 2,285,578 Impaired loans A loan is impaired when, based on current information and events, it is probable that a creditor will be unable to collect all amounts due according to the contractual terms of the loan agreement. When a loan is impaired, the Company measures impairment based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except that as a practical expedient, the Company measures impairment based on a loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. Loans are charged-off when management believes that the collectability of the loan’s principal is not probable. The specific factors that management considers in making the determination that the collectability of the loan’s principal is not probable include: the delinquency status of the loan, the fair value of the collateral, if secured, and the financial strength of the borrower and/or guarantors. For collateral dependent loans, the amount of the recorded investment in a loan that exceeds the fair value of the collateral is charged-off against the allowance for loan losses in lieu of an allocation of a specific allowance amount when such an amount has been identified definitively as uncollectible. The Company’s policy for recognizing interest income on impaired loans is contained within Note 1 of the consolidated financial statements contained in the Company’s Annual Report for the fiscal year ended December 31, 2018. The following is information pertaining to impaired loans for September 30, 2019: Carrying Unpaid Required Average Interest Average Interest (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 87 306 — 89 2 87 6 Municipal — — — — — — — Commercial real estate 167 194 — 729 — 529 — Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 254 $ 500 $ — $ 818 $ 2 $ 616 $ 6 With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 116 116 2 310 2 299 6 Municipal — — — — — — — Commercial real estate 2,206 2,326 86 2,140 23 2,350 67 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 2,322 $ 2,442 $ 88 $ 2,450 $ 25 $ 2,649 $ 73 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 203 422 2 399 4 386 12 Municipal — — — — — — — Commercial real estate 2,373 2,520 86 2,869 23 2,879 67 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 2,576 $ 2,942 $ 88 $ 3,268 $ 27 $ 3,265 $ 79 The following is information pertaining to impaired loans for September 30, 2018: Carrying Unpaid Required Average 9 Interest 9 Average 9 9 Interest 9 9 (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 84 282 — 56 — 47 — Municipal — — — — — — — Commercial real estate 196 219 — 280 — 267 — Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 280 $ 501 $ — $ 336 $ — $ 314 $ — With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 576 593 93 589 5 490 14 Municipal — — — — — — — Commercial real estate 2,484 2,597 95 2,262 24 2,278 71 Residential real estate 2,675 2,675 350 2,675 — 3,136 80 Consumer — — — — — — — Home equity — — — — — — — Total $ 5,735 $ 5,865 $ 538 $ 5,526 $ 29 $ 5,904 $ 165 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 660 875 93 645 5 537 14 Municipal — — — — — — — Commercial real estate 2,680 2,816 95 2,542 24 2,545 71 Residential real estate 2,675 2,675 350 2,675 — 3,136 80 Consumer — — — — — — — Home equity — — — — — — — Total $ 6,015 $ 6,366 $ 538 $ 5,862 $ 29 $ 6,218 $ 165 Troubled debt restructurings are identified as modification s There was no troubled debt restructuring that occurred during the nine month period ended September 30, 2019. Also, there were no commitments to lend additional funds to troubled debt restructuring borrowers. There were no troubled debt restructurings that subsequently defaulted during the first nine months of 2019. There was one residential real estate loan and one consumer loan that were modified during the first quarter of 2018. The loans were modified by reducing the interest rates as well as extending the terms on both loans. The pre-modification and post-modification outstanding recorded investment was $ 2,675 1 2,675,000 This troubled debt restructuring became other real estate owned during the fourth quarter of 2018 and subsequently sold during the third quarter of 2019.

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Reclassifications Out of Accumulated Other Comprehensive Income	Note 6. Reclassifications Out of Accumulated Other Comprehensive Income Amount Reclassified from Accumulated Other Comprehensive Income Details about Accumulated Other Comprehensive Income Components Three Three Affected Line Item in the Statement where Net Income is Presented (in thousands) Unrealized gains and losses on available-for-sale securities $ 54 $ 105 Net gains on sales of Tax (expense) or benefit (15 ) (29 ) Provision for income taxes Net of tax $ 39 $ 76 Net income Accretion of unrealized losses transferred $ (209 ) $ (323 ) Interest on securities Tax (expense) or benefit 54 85 Provision for income taxes Net of tax $ (155 ) $ (238 ) Net income Amortization of defined benefit pension items Prior-service costs $ (29 ) $ (4 )(b) Salaries and employee benefits Actuarial gains (losses) (337 ) (402 )(b) Salaries and employee benefits Total before tax (366 ) (406 ) Income before taxes Tax (expense) or benefit 103 114 Provision for income taxes Net of tax $ (263 ) $ (292 ) Net income Details about Accumulated Other Comprehensive Income Components Nine Nine Affected Line Item in the Statement where Net Income is Presented (in thousands) Unrealized gains and losses on available-for-sale securities $ 61 $ 302 Net gains on sales of Tax (expense) or benefit (17 ) (85 ) Provision for income taxes Net of tax $ 44 $ 217 Net income Accretion of unrealized losses transferred $ (779 ) $ (1,186 ) Interest on securities Tax (expense) or benefit 205 314 Provision for income taxes Net of tax $ (574 ) $ (872 ) Net income Amortization of defined benefit pension items Prior-service costs $ (86 ) $ (12 ) ( b Salaries and employee benefits Actuarial gains (losses) (1,013 ) (1,207 ) ( b Salaries and employee benefits Total before tax (1,099 ) (1,219 ) Income before taxes Tax (expense) or benefit 309 342 Provision for income taxes Net of tax $ (790 ) $ (877 ) Net income (a) Amount in parentheses indicates reductions to net income. (b) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Employee Benefits footnote (Note 8) for additional details).

Earnings per share ("EPS")

Earnings per share ("EPS")	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings per share ("EPS")	Note 7. Earnings per Share (“EPS”) Class A and Class B shares participate equally in undistributed earnings. Under the Company’s Articles of Organization, the holders of Class A Common Stock are entitled to receive dividends per share equal to at least 200% of dividends paid, if any, from time to time, on each share of Class B Common Stock. Diluted EPS includes the dilutive effect of common stock equivalents; basic EPS excludes all common stock equivalents. The Company had no common stock equivalents outstanding for the periods ended September 30, 2019 and 2018. The following table is a reconciliation of basic EPS and diluted EPS. Three Months Ended Nine Months Ended (in thousands except share and per share data) 2019 2018 2019 2018 Basic EPS Computation: Numerator: Net income, Class A $ 7,986 $ 7,535 $ 22,849 $ 20,674 Net income, Class B 2,098 2,046 6,118 5,614 Denominator: Weighted average shares outstanding, Class A 3,650,449 3,608,329 3,627,076 3,608,129 Weighted average shares outstanding, Class B 1,917,460 1,959,580 1,940,833 1,959,780 Basic EPS, Class A $ 2.19 $ 2.09 $ 6.30 $ 5.73 Basic EPS, Class B 1.09 1.04 3.15 2.86 Diluted EPS Computation: Numerator: Net income, Class A $ 7,986 $ 7,535 $ 22,849 $ 20,674 Net income, Class B 2,098 2,046 6,118 5,614 Total net income, for diluted EPS, Class A computation 10,084 9,581 28,967 26,288 Denominator: Weighted average shares outstanding, basic, Class A 3,650,449 3,608,329 3,627,076 3,608,129 Weighted average shares outstanding, Class B 1,917,460 1,959,580 1,940,833 1,959,780 Weighted average shares outstanding diluted, Class A 5,567,909 5,567,909 5,567,909 5,567,909 Weighted average shares outstanding, Class B 1,917,460 1,959,580 1,940,833 1,959,780 Diluted EPS, Class A $ 1.81 $ 1.72 $ 5.20 $ 4.72 Diluted EPS, Class B 1.09 1.04 3.15 2.86

Employee Benefits

Employee Benefits	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Employee Benefits	Note 8. Employee Benefits The Company provides pension benefits to its employees under a noncontributory, defined benefit plan which is funded on a current basis in compliance with the requirements of the Employee Retirement Income Security Act of 1974 (“ERISA”) and recognizes costs over the estimated employee service period. The Company also has a Supplemental Executive Insurance/Retirement Plan (the “Supplemental Plan”) which is limited to certain officers and employees of the Company. The Supplemental Plan is accrued on a current basis and recognizes costs over the estimated employee service period. Executive officers of the Company and its subsidiaries who have at least one year of service may participate in the Supplemental Plan. The Supplemental Plan is voluntary, and participants are required to contribute to its cost. Life insurance policies, which are owned by the Company, are purchased covering the lives of each participant. Components of Net Periodic Benefit Cost for the Three Months Ended September 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 276 $ 353 $ 256 $ 277 Interest 473 371 482 346 Expected return on plan assets (819 ) (954 ) — — Recognized prior service cost (benefit) — (25 ) 28 29 Recognized net actuarial losses 229 226 109 176 Net periodic benefit cost (credit) $ 159 $ (29 ) $ 875 $ 828 Components of Net Periodic Benefit Cost for the Nine Months Ended September 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 828 $ 1,059 $ 768 $ 831 Interest 1,419 1,111 1,445 1,040 Expected return on plan assets (2,457 ) (2,863 ) — — Recognized prior service cost (benefit) — (75 ) 86 87 Recognized net actuarial losses 687 680 326 527 Net periodic benefit cost (credit) $ 477 $ (88 ) $ 2,625 $ 2,485 Approximately $1,506,000 and $507,000 of costs other than service costs, from the table above, are included in other expenses for the nine months ended September 30, 2019 and 2018, respectively. Contributions The Company does not intend to contribute to the Defined Benefit Pension Plan in 2019.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 9. Fair Value Measurements The Company follows FASB ASC 820-10, Fair Value Measurements and Disclosures and ASU 2016-1, “Financial Instruments-Overall” (Subtopic 825-10) Recognition and Measurement of Financial Assets and Financial Liabilities Level I – Quoted prices are available in active markets for identical assets or liabilities as of the reported date. The type of financial instruments included in Level I are highly liquid cash instruments with quoted prices such as G-7 government, agency securities, listed equities and money market securities, as well as listed derivative instruments. Level II – Pricing inputs are other than quoted prices in active markets, which are either directly or indirectly observable as of the reported date. The nature of these financial instruments include cash instruments for which quoted prices are available but traded less frequently, derivative instruments whose fair value have been derived using a model where inputs to the model are directly observable in the market, or can be derived principally from or corroborated by observable market data, and instruments that are fair valued using other financial instruments, the parameters of which can be directly observed. Instruments which are generally included in this category are corporate bonds and loans, mortgage whole loans, municipal bonds, and OTC derivatives. Level III – Instruments that have little to no pricing observability as of the reported date. These financial instruments do not have two-way markets and are measured using management’s best estimate of fair value, where the inputs into the determination of fair value require significant management judgment or estimation. Instruments that are included in this category generally include certain commercial mortgage loans, certain private equity investments, and distressed debt and non-investment grade residual interests in securitizations, as well as certain highly structured OTC derivative contracts. The results of the fair value hierarchy as of September 30, 2019, are as follows: Financial Instruments Measured at Fair Value on a Recurring Basis: Securities AFS Fair Value Measurements Using Carrying Quoted Prices Significant Significant (in thousands) SBA Backed Securities $ 58,664 $ — $ 58,664 $ — U.S. Government Agency and Sponsored Mortgage-Backed Securities 170,282 — 170,282 — Privately Issued Residential Mortgage- 579 — 579 — Obligations Issued by States and Political Subdivisions 28,576 — 4,775 23,801 Other Debt Securities 3,638 — 3,638 — Total $ 261,739 $ — $ 237,938 $ 23,801 Equity Securities $ 1,672 $ 324 $ 1,348 $ — Financial Instruments Measured at Fair Value on a Non-recurring Basis: Impaired Loans $ 173 $ — $ — $ 173 Impaired loan balances represent those collateral dependent loans where management has estimated the credit loss by comparing the loan’s carrying value against the expected realizable fair value of the collateral. Fair value is generally determined through a review process that includes independent appraisals, discounted cash flows, or other external assessments of the underlying collateral, which generally include various Level 3 inputs which are not observable. The Company discounts the fair values, as appropriate, based on management’s observations of the local real estate market for loans in this category. Appraisals, discounted cash flows and real estate tax assessments are reviewed quarterly. There is no specific policy regarding how frequently appraisals will be updated. Adjustments are made to appraisals and real estate tax assessments based on management’s estimate of changes in real estate values. All impaired loans have been reviewed during the past quarter using either a discounted cash flow analysis, appraisal of collateral or other type of real estate tax assessment. The types of adjustments that are made to specific provisions relate d The following table presents additional information about assets measured at fair value on a recurring and nonrecurring basis for which the Company has utilized Level 3 inputs to determine fair value (dollars in thousands). Management continues to monitor the assumptions used to value the assets listed below. Asset Fair Value Valuation Technique Unobservable Input Unobservable Input Securities AFS (4) $ 23,801 Discounted cash flow Discount rate 1.7%-3.1% (3) Impaired Loans $ 173 Appraisal of collateral (1) Appraisal adjustments (2) 0%-30% discount (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated expenses. (3) Weighted averages. (4) Municipal securities generally have maturities of one year or less and, therefore, the amortized cost equates to the fair value. The changes in Level 3 securities for the nine month period ended September 30, 2019 are shown in the table below: Obligations (in thousands) Balance at December 31, 2018 $ 88,728 Purchases 13,290 Maturities and calls (78,196 ) Amortization (21 ) Balance at September 30, 2019 $ 23,801 The amortized cost of Level 3 securities was $23,801,000 at September 30, 2019 with an unrealized loss of $0. The securities in this category are generally municipal securities with no readily determinable fair value. Management evaluated the fair value of these securities based on an evaluation of the underlying issuer, prevailing rates and market liquidity. The fair value of impaired loans decreased by $78,000, for the first nine months of 2019, mainly attributable to one loan that was removed from impaired loans. There were no liabilities measured at fair value on a recurring or nonrecurring basis during the nine month period ended September 30, 2019. The changes in Level 3 securities for the nine month period ended September 30, 2018, are shown in the table below: Auction Rate Obligations Total (in thousands) Balance at December 31, 2017 $ 4,459 $ 78,141 $ 82,600 Purchases — 105,837 105,837 Maturities and calls — (72,640 ) (72,640 ) Transfer to Level 2 (4,459 ) — (4,459 ) Amortization — (104 ) (104 ) Changes in fair value — — — Balance at September 30, 2018 $ — $ 111,234 $ 111,234 The amortized cost of Level 3 securities was $111,234,000 at September 30, 2018 with an unrealized loss of $0. The securities in this category are generally municipal securities with no readily determinable fair. Management evaluated the fair value of these securities based on an evaluation of the underlying issuer, prevailing rates and market liquidity. There was one transfer of a security from level 3 to level 2 for the nine months ended September 30, 2018 as a result of increased trading activity and quoted market prices. There were no liabilities measured at fair value on a recurring or nonrecurring basis during the nine month period ended September 30, 2018. The results of the fair value hierarchy as of December 31, 2018, are as follows: Financial Instruments Measured at Fair Value on a Recurring Basis: Securities AFS Fair Value Measurements Using Carrying Quoted Prices Significant Significant (in thousands) U.S. Treasury $ 1,992 $ — $ 1,992 $ — U.S. Government Sponsored Enterprises 3,915 — 3,915 — SBA Backed Securities 70,194 — 70,194 — U.S. Government Agency and Sponsored Mortgage-Backed Securities 162,890 — 162,890 — Privately Issued Residential Mortgage- 672 — 672 — Obligations Issued by States and Political Subdivisions 93,503 — 4,775 88,728 Other Debt Securities 3,593 3,593 Total $ 336,759 $ — $ 248,031 $ 88,728 Equity Securities $ 1,596 $ 293 $ 1,303 $ — Financial Instruments Measured at Fair Value on a Non-recurring Basis: Other Real Estate Owned $ 2,225 $ — $ — $ 2,225 Impaired Loans $ 251 $ — $ — $ 251 Impaired loan balances represent those collateral dependent loans where management has estimated the credit loss by comparing the loan’s carrying value against the expected realizable fair value of the collateral. Fair value is generally determined through a review process that includes independent appraisals, discounted cash flows, or other external assessments of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. The Company discounts the fair values, as appropriate, based on management’s observations of the local real estate market for loans in this category. Appraisals, discounted cash flows and real estate tax assessments are reviewed quarterly. There is no specific policy regarding how frequently appraisals will be updated. Adjustments are made to appraisals and real estate tax assessments based on management’s estimate of changes in real estate values. Within the past twelve months there have been no updated appraisals, however, all impaired loans have been reviewed during the past quarter using either a discounted cash flow analysis, appraisal of collateral or other type of real estate tax assessment. The types of adjustments that are made to specific provisions relate to impaired loans recognized for 2018 for the estimated credit loss amounted to $540,000. There was a transfer of an auction rate security during 2018 from level 3 to level 2. Quoted prices on the auction rate security became available but traded infrequently. There were no other transfers between level 1, 2 and 3 for the year ended December 31, 2018. There were no liabilities measured at fair value on a recurring or nonrecurring basis during the year ended December 31, 2018. The following table presents additional information about assets measured at fair value on a recurring and nonrecurring basis for which the Company has utilized Level 3 inputs to determine fair value (dollars in thousands). Management continues to monitor the assumptions used to value the assets listed below. Asset Fair Value Valuation Technique Unobservable Input Unobservable Input Securities AFS (4) $ 88,728 Discounted cash flow Discount rate 2.1%-4.1% (3) Other Real Estate Owned $ 2,225 Appraisal of collateral (1) Appraisal adjustments (2) 30% discount Impaired Loans $ 251 Appraisal of collateral (1) Appraisal adjustments (2) 0%-30% discount (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated expenses. (3) Weighted averages. (4) Municipal securities generally have maturities of one year or less and, therefore, the amortized cost equates to the fair value.

Fair Values of Financial Instru

Fair Values of Financial Instruments	9 Months Ended
	Sep. 30, 2019
Investments, All Other Investments [Abstract]
Fair Values of Financial Instruments	Note 10. Fair Values of Financial Instruments The following methods and assumptions were used by the Company in estimating fair values of its financial instruments. Excluded from this disclosure are all non-financial instruments. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company. The assumptions used below are expected to approximate those that market participants would use in valuing these financial instruments. Fair value estimates are made at a specific point in time, based on available market information and judgments about the financial instrument, including estimates of timing, amount of expected future cash flows and the credit standing of the issuer. Such estimates do not consider the tax impact of the realization of unrealized gains or losses. In some cases, the fair value estimates cannot be substantiated by comparison to independent markets. In addition, the disclosed fair value may not be realized in the immediate settlement of the financial instrument. Care should be exercised in deriving conclusions about our business, its value or financial position based on the fair value information of financial instruments presented below. Securities Held-to-Maturity The fair values of these securities were based on quoted market prices, where available, as provided by third-party investment portfolio pricing vendors. If quoted market prices were not available, fair values provided by the vendors were based on quoted market prices of comparable instruments in active markets and/or based on a matrix pricing methodology which employs The Bond Market Association’s standard calculations for cash flow and price/yield analysis, live benchmark bond pricing and terms/condition data available from major pricing sources. Management regards the inputs and methods used by third party pricing vendors to be “Level 2 inputs and methods” as defined in the “fair value hierarchy” provided by FASB. Loans The fair value of loans is estimated using the exit price notion consistent with Topic 820, Fair Value Measurement. Fair value is determined based on a discounted cash flow analysis. The discounted cash flow analysis was based on the contractual maturity of the loan and market indications of rates, prepayment speeds, defaults and credit risk. For certain non-performing assets , Time Deposits The fair value of time deposits was estimated using a discounted cash flow approach that applies prevailing market interest rates for similar maturity instruments. The fair values of the Company’s time deposit liabilities do not take into consideration the value of the Company’s long-term relationships with depositors, which may have significant value. Other Borrowed Funds The fair value of other borrowed funds is based on the discounted value of contractual cash flows. The discount rate used is estimated based on the rates currently offered for other borrowed funds of similar remaining maturities. Subordinated Debentures The fair value of subordinated debentures is based on the discounted value of contractual cash flows. The discount rate used is estimated based on the rates currently offered for other subordinated debentures of similar remaining maturities. The following presents (in thousands) the carrying amount, estimated fair value, and placement in the fair value hierarchy of the Company’s financial instruments as of September 30, 2019 and December 31, 2018. 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, short-term investments, FHLBB stock and accrued interest receivable. Financial liabilities for which the fair value approximates carrying value include non-maturity deposits, short-term borrowings and accrued interest payable. September 30, 2019 Carrying Estimated Fair Value Level 2 Level 3 (in thousands) Financial assets: Securities held-to-maturity $ 2,164,135 $ 2,188,465 $ — $ 2,188,465 $ — Loans (1) 2,346,564 2,398,515 — — 2,398,515 Financial liabilities: Time deposits 533,074 532,135 — 532,135 — Other borrowed funds 209,188 209,263 — 209,263 — Subordinated debentures 36,083 36,083 — 36,083 — December 31, 2018 Financial assets: Securities held-to-maturity $ 2,046,647 $ 1,991,421 $ — $ 1,991,421 $ — Loans (1) 2,257,035 2,279,712 — — 2,279,712 Financial liabilities: Time deposits 560,579 559,988 — 559,988 — Other borrowed funds 202,378 203,122 — 203,122 — Subordinated debentures 36,083 36,083 — 36,083 — (1) Comprised of loans (including collateral dependent impaired loans), net of deferred loan costs and the allowance for loan losses. Limitations Fair value estimates are made at a specific point in time, based on relevant market information and information about the type of financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Bank’s entire holdings of a particular financial instrument. Because no active market exists for some of the Bank’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, cash flows, current economic conditions, risk characteristics and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in assumptions and changes in the loan, debt and interest rate markets could significantly affect the estimates. Further, the income tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on the fair value estimates and have not been considered.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Note 11. Revenue from Contracts with Customers Revenue from contracts with customers in the scope of ASC Topic 606 is measured based on the consideration specified in the contract with a customer, and excludes amounts collected on behalf of third parties. The Company recognizes revenue from contracts with customers when it satisfies its performance obligations. The Company’s performance obligations are typically satisfied as services are rendered, and our contracts do not include multiple performance obligations. Payment is generally collected at the time services are rendered, or monthly. Unsatisfied performance obligations at the report date are not material to our consolidated financial statements. The Company pays sales commissions to its employees in accordance with certain incentive plans. The Company expenses sales commissions when incurred if we do not expect to recover these costs from the terms of the contract with the customer. Sales commissions are included in compensation expense. In certain cases, other parties are involved with providing products and services to our customers. If the Company is a principal in the transaction (providing goods or services itself), revenues are reported based on the gross consideration received from the customer and any related expenses are reported gross in noninterest expense. If the Company is an agent in the transaction (arranging for another party to provide goods or services), the Company reports its net fee or commission retained as revenue. Waivers and reversals are recorded as a reduction of revenue either when the revenue is recognized by the Company or at the time the waiver or reversal is earned by the customer. A. Change in accounting policy The Company adopted Topic 606 Revenue from Contracts with Customers third The Company applied Topic 606 using the cumulative effect method. There was no cumulative effect adjustment as of January 1, 2018, and there were no material changes to the financial statements at or for the nine months ended September 30, 2019 and September 30, 2018, respectively, as a result of adopting Topic 606. B. Practical Expedients The Company applies the practical expedient in paragraph 606-10-50-14 and does not disclose information about remaining performance obligations that have original expected durations of one year or less. The Company applies the practical expedient in paragraph 606-10-32-18 and does not adjust the consideration from customers for the effects of a significant financing component if at contract inception the period between when the entity transfers the goods or services and when the customer pays for that good or service will be one year or less. C. Nature of goods and services The vast majority of the Company’s revenue is specifically out-of-scope of Topic 606. For the revenue in-scope, the following is a description of principal activities, separated by the timing of revenue recognition, from which the Company generates its revenue from contracts with customers. a. Revenue earned at a point in time – Examples of revenue earned at a point in time are ATM transaction fees, wire transfer fees, NSF fees, credit and debit card interchange fees and foreign exchange transaction fees. Revenue is generally derived from transactional information accumulated by our systems and is recognized as revenue immediately as the transactions occur or upon providing the service to complete the customer’s transaction. The Company is the principal in each of these contracts, with the exception of credit and debit card interchange fees, in which case we are acting as the agent and record revenue net of expenses paid to the principal. b. Revenue earned over time – The Company earns revenue from contracts with customers in a variety of ways in which the revenue is earned over a period of time – generally monthly or quarterly. Examples of this type of revenue are deposit account service fees, lockbox fees, investment management fees, merchant referral services, and safe deposit box fees. Account service charges, management fees and referral fees are recognized on a monthly basis while any transaction based income is recorded as the activity occurs. Revenue is primarily based on the number and type of transactions or assets managed and is generally derived from transactional information accumulated by our systems. Revenue is recorded in the same period as the related transactions occur or services are rendered to the customer. D. Disaggregation of revenue The following table presents total revenues as presented in the Consolidated Statements of Income and the related amounts which are from contracts with customers within the scope of Topic 606. As illustrated here, the vast majority of our revenues are specifically excluded from the scope of Topic 606. Nine Revenue from Nine Revenue from (dollars in thousands) Net $ 70,458 $ — $ 68,871 $ — Noninterest income: Service charges on deposit accounts 6,801 6,801 6,268 6,268 Lockbox fees 3,018 3,018 2,304 2,304 Net gains on sales of securities 61 — 302 — Gains on sales of mortgage loans 154 — — — Other income 3,676 2,338 3,210 2,215 Total noninterest income 13,710 12,157 12,084 10,787 Total reven ues $ 84,168 $ 12,157 $ 80,955 $ 10,787 Three Revenue from Three Revenue from (dollars in thousands) Net $ 23,770 $ — $ 23,204 $ — Noninterest income: Service charges on deposit accounts 2,310 2,310 2,137 2,137 Lockbox fees 937 937 892 892 Net gains on sales of securities 53 — 105 — Gains on sales of mortgage loans — — — — Other income 986 728 1,035 751 Total noninterest income 4,286 3,975 4,169 3,780 Total revenues $ 28,056 $ 3,975 $ 27,373 $ 3,780 The following table provides information about receivables with customers. September 30, 2019 December 31, 2018 (dollars in thousands) Receivables, which are included in “Other assets” $ 1,142 $ 1,205

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	Note 12. Leases The Company has operating leases primarily for branch locations as well as data processing centers. The Company’s operating leases have remaining lease terms of 1 year to 32 years, some of which include options to extend the leases for up to 10 years, and some of which include options to terminate the leases within 1 year. The sublease expires in 2022 with an option to terminate and no option to extend. Variable lease costs include costs that are not included in the lease liability. The components of lease expense were as follows: Three Months Nine Months (in thousands) Operating lease cost $ 550 $ 1,676 Variable lease cost 121 405 Total lease cost $ 671 $ 2,081 Supplemental cash flow information related to leases was as follows: Three Months Nine Months (in thousands) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 528 $ 1,605 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 433 $ 1,318 Supplemental balance sheet information related to leases was as follows: 9/30/2019 (in thousands, except lease term and discount rate) Operating Leases: Operating lease right-of-use assets $ 12,944 Operating lease liabilities $ 13,101 Weighted Average Remaining Lease Term: Operating Leases 11 Weighted Average Discount Rate: Operating Leases 3.5 % A summary of future minimum rental payments under such leases as the dates indicated follows: Minimum Rental Payments September 30, 2019 December 31, 2018 (in thousands) Year Ending December 31, 2019 $ 459 $ 2,490 2020 2,038 2,170 2021 1,759 1,694 2022 1,603 1,331 2023 1,541 1,104 Thereafter 8,570 1,074 Total lease payments $ 15,970 $ 9,863 Less imputed interest (2,869 ) Present value of lease liability $ 13,101

Recent Accounting Developments

Recent Accounting Developments (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Developments	Recently Adopted Accounting Standards Updates In July 2017, FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815): I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interest with a Scope Exception. For public entities, this ASU is effective for annual reporting periods beginning after December 15, 2018. The effect of this update did not have a material impact on the Company’s consolidated financial position. In March 2017, the FASB issued ASU 2017-08, Receivables — Nonrefundable Fees and Other Costs (Subtopic 310-20) Premium Amortization of Purchased Callable Debt. The FASB is issuing this ASU to amend the amortization period for certain purchased callable debt securities held at a premium. The FASB is shortening the amortization period for the premium to the earliest call date. Under current generally accepted accounting principles (GAAP), entities generally amortize the premium as an adjustment of yield over the contractual life of the instrument. For public business entities, the amendments in this ASU are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The effect of this update did not have a material impact on the Company’s consolidated financial position. In February 2016, the FASB issued ASU 2016-02, Leases. This ASU required lessees to put most leases on their balance sheet but recognize expenses on their income statements in a manner similar to today’s accounting. This ASU also eliminated today’s real estate-specific provisions for all companies. For lessors, this ASU modified the classification criteria and the accounting for sales-type and direct financing leases. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods therein. The Company also reviewed contracts to determine if they contain embedded leases. The Company’s balance sheet impact was $15.1 million as of January 1, 2019. This amount was recorded as a right of use asset , included in other assets, with a corresponding lease liability , included in other liabilities . In July 2018, ASU 2018-10, “Codification Improvements to Topic 842, Leases” (“ASU 2018-10”) was issued to provide more detailed guidance and additional clarification for implementing ASU 2016-02. Also in July 2018, ASU 2018-11, “Targeted Improvements” (“ASU 2018-11”) was issued and allows for an optional transition method in which the provisions of Topic 842 would be applied upon the adoption date and would not have to be retroactively applied to the earliest reporting period presented in the consolidated financial statements.” The Company used this optional transition method for the adoption of Topic 842. Accounting Standards Issued but not yet Adopted The following list identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU was issued to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this ASU replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company is in the process of implementing this ASU, has purchased a software solution and is capturing information needed to implement this ASU. As part of the FASB ASC 326 implementation process the company is using two models: a rating migration model and a probability of default model. The probability of default model is based primarily on four components: loss history, product lifecycle, behavioral attributes and the economic environment. The ratings migration model is designed to estimate loss reserves according to the CECL standard for rated loans or similar instruments. The model structure follows a grade migration approach, where the default rate is based on the probability of each grade transition which is modeled using historical data. The Company has started to input information into the models, and is running the software program and comparing to existing results. In addition, the Company has also begun developing accounting policies, as well as designing and implementing new internal controls relevant to the updated methodologies and models. The Company has not determined the dollar impact as of September 30, 2019. The securities held-to-maturity 2016-13 Since ASU 2016-13, the FASB has issued amendments intended on improving the clarification of the amendment, ASU 2018-19 Codification Improvements to Topic 326, Financial Instruments – Credit Losses and ASU 2019-04 Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging. The amendment in ASU 2018-19 was issued in November 2018 and was intended to clarify that receivables arising from operating leases are not within the scope of Subtopic 326-20. Instead, impairment of receivables arising from operating leases should be accounted for in accordance with Topic 842, Leases. The amendment in ASU 2019-04 was issued in April 2019 and was intended to clarify stakeholders’ specific issues about certain aspects of the amendments in ASU 2016-13. ASU 2019-05 Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief was also issued in May 2019. This ASU provides entities the option to irrevocably elect the fair value option for certain financial assets previously measured at amortized costs basis. The fair value option election does not apply to held-to-maturity debt securities. An entity that elects the fair value option should subsequently apply the guidance in Subtopics 820-10, Fair Value Measurement—Overall. The amendments in this ASU should be applied on a modified-retrospective basis by means of a cumulative-effect adjustment to the opening balance of retained earnings balance in the statement of financial position as of the date that an entity early adopted the amendments in ASU 2016-13. In August 2018, FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force) The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). This ASU is effective for annual reporting periods beginning after December 15, 2019. The effect of this update is not expected to have a material impact on the Company’s consolidated financial position. In August 2018, FASB issued ASU 2018-14, 715-20): In August 2018, FASB issued ASU 2018-13, In January 2017, the FASB issued ASU 2017-04, Intangibles — Goodwill and Other (Topic 350). This ASU was issued to simplify the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. For public entities, this ASU is effective for the fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted and application should be on a prospective basis. The effect of this update is not expected to have a material impact on the Company’s consolidated financial position. Securities and Exchange Commission (SEC) ruling: In August 2018, the SEC issued a final rule that amends certain of the Commission’s disclosure requirements “that have become redundant, duplicative, overlapping, outdated, or superseded, in light of other Commission disclosure requirements, U.S. GAAP, or changes in the information environment.” The financial reporting implications of the final rule’s amendments may vary by company, but the changes are generally expected to reduce or eliminate some of an SEC registrant’s disclosure requirements. In limited circumstances, however, the amendments may expand those requirements, including those related to interim disclosures about changes in stockholders’ equity. Under the requirements, registrants must now analyze changes in stockholders’ equity, in the form of a reconciliation, for “the current and comparative year-to-date periods, with subtotals for each interim period.” Beginning with its March 31, 2019 filing, the Company included a reconciliation for the current quarter and year-to-date interim periods as well as the comparative periods of the prior years (i.e., a reconciliation covering each period for which an income statement is presented).

Securities Available-for-Sale (

Securities Available-for-Sale (Tables)	9 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Summary of Securities Available-for-Sale	September 30, 2019 December 31, 2018 Amortized Gross Gross Fair Amortized Gross Gross Fair (in thousands) U.S. Treasury $ — $ — $ — $ — $ 2,000 $ — $ 8 $ 1,992 U.S. Government Sponsored Enterprises — — — — 3,946 — 31 3,915 SBA Backed Securities 58,714 51 101 58,664 70,477 1 284 70,194 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 170,532 189 439 170,282 162,604 536 250 162,890 Privately Issued Residential Mortgage-Backed Securities 574 6 1 579 679 3 10 672 Obligations Issued by States and Political Subdivisions 28,519 57 — 28,576 93,445 58 — 93,503 Other Debt Securities 3,600 64 26 3,638 3,600 37 44 3,593 Total $ 261,939 $ 367 $ 567 $ 261,739 $ 336,751 $ 635 $ 627 $ 336,759
Estimated Maturity Distribution of Securities Available-for-Sale	The following table shows the maturity distribution of the Company’s securities available-for-sale at September 30, 2019. Amortized Fair (in thousands) Within one year $ 26,187 $ 26,184 After one but within five years 134,881 134,811 After five but within ten years 85,551 85,378 More than 10 years 15,320 15,366 Total $ 261,939 $ 261,739
Continuous Unrealized Loss Position for 12 Months or Less and 12 Months and Longer	The following table shows the temporarily impaired securities of the Company’s available-for-sale portfolio at September 30, 2019. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for less than 12 months and a continuous loss position for 12 months or longer. There are 24 and 18 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 134 holdings at September 30, 2019. September 30, 2019 Less than 12 months 12 months or longer Total Temporarily Impaired Investments Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ — $ — $ — $ — $ — $ — U.S. Government Sponsored Enterprises — — — — — — SBA Backed Securities 11,133 11 24,944 90 36,077 101 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 81,305 264 27,872 175 109,177 439 Privately Issued Residential Mortgage-Backed Securities — — 282 1 282 1 Obligations Issued by States and Political Subdivisions — — — — — — Other Debt Securities 800 1 475 25 1,275 26 Total temporarily impaired securities $ 93,238 $ 276 $ 53,573 $ 291 $ 146,811 $ 567 The following table shows the temporarily impaired securities of the Company’s available-for-sale portfolio at December 31, 2018. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for less than 12 months and a continuous loss position for 12 months or longer. There are 10 and 30 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 190 holdings at December 31, 2018. December 31, 2018 Less than 12 months 12 months or longer Total Temporarily Impaired Investments Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ — $ — $ 1,992 $ 8 $ 1,992 $ 8 U.S. Government Sponsored Enterprises 3,914 31 — — 3,914 31 SBA Backed Securities 17,950 28 44,323 256 62,273 284 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 19,244 21 45,782 229 65,026 250 Privately Issued Residential Mortgage-Backed Securities — — 495 10 495 10 Obligations Issued by States and Political Subdivisions — — — — — — Other Debt Securities — — 455 44 455 44 Total temporarily impaired securities $ 41,108 $ 80 $ 93,047 $ 547 $ 134,155 $ 627

Investment Securities Held-to_2

Investment Securities Held-to-Maturity (Tables)	9 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Summary of Held-to-Maturity Securities	September 30, 2019 December 31, 2018 Amortized Gross Gross Losses Estimated Amortized Gross Gross Estimated (in thousands) U.S. Treasury $ — $ — $ — $ — $ 9,960 $ — $ 2 $ 9,958 U.S. Government Sponsored Enterprises 121,516 653 67 122,102 234,228 336 803 233,761 SBA Backed Securities 47,126 452 66 47,512 52,051 — 2,065 49,986 U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities 1,995,493 29,911 6,553 2,018,851 1,750,408 2,324 55,016 1,697,716 Total $ 2,164,135 $ 31,016 $ 6,686 $ 2,188,465 $ 2,046,647 $ 2,660 $ 57,886 $ 1,991,421
Company's Securities Held-to-Maturity	The following table shows the maturity distribution of the Company’s securities held-to-maturity at September 30, 2019. Amortized Fair (in thousands) Within one year $ 70,980 $ 71,260 After one but within five years 1,809,564 1,829,087 After five but within ten years 271,068 275,192 More than ten years 12,523 12,926 Total $ 2,164,135 $ 2,188,465
Unrealized Market Loss of Securities	The following table shows the temporarily impaired securities of the Company’s held-to-maturity portfolio September 30, 2019. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for 12 months or less and a continuous loss position for 12 months or longer. There are 44 and 112 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 505 holdings at September 30, 2019. September 30, 2019 Less Than 12 Months 12 Months or Longer Total Temporarily Impaired Investments Fair Value Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ — $ — $ — $ — $ — $ — U.S. Government Sponsored Enterprises 9,976 22 9,954 45 19,930 67 SBA Backed Securities 13,673 66 — — 13,673 66 U.S. Government Agency and Sponsored Enterprise Mortgage- Backed Securities 163,889 816 430,714 5,737 594,603 6,553 Total temporarily impaired securities $ 187,538 $ 904 $ 440,668 $ 5,782 $ 628,206 $ 6,686 The following table shows the temporarily impaired securities of the Company’s held-to-maturity portfolio at December 31, 2018. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for less than 12 months and a continuous loss position for 12 months or longer. There are 56 and 315 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 475 holdings at December 31, 2018. December 31, 2018 Less Than 12 Months 12 Months or Longer Total Temporarily Impaired Investments Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) U.S. Treasury $ 9,958 $ 2 $ — $ — $ 9,958 $ 2 U.S. Government Sponsored Enterprises 9,849 42 69,499 761 79,348 803 SBA Backed Securities — — 49,987 2,065 49,987 2,065 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 188,125 2,032 1,249,689 52,984 1,437,814 55,016 Total temporarily impaired securities $ 207,932 $ 2,076 $ 1,369,175 $ 55,810 $ 1,577,107 $ 57,886

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Analysis of the allowance for loan losses	The following table summarizes the changes in the Company’s allowance for loan losses for the periods indicated. Three months ended Nine months ended 2019 2018 2019 2018 (in thousands) Allowance for loan losses, beginning of period $ 29,070 $ 27,144 $ 28,543 $ 26,255 Loans charged off (118 ) (89 ) (336 ) (247 ) Recoveries on loans previously charged-off 70 1,490 190 1,637 Net recoveries (charge-offs) (48 ) 1,401 (146 ) 1,390 Provision charged to expense 75 — 700 900 Allowance for loan losses, end of period $ 29,097 $ 28,545 $ 29,097 $ 28,545
Summary of Allowance for Loan Losses	Further information pertaining to the allowance for loan losses for the three months ending September 30, 2019 is as Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at June 30, 2019 $ 1,052 $ 11,338 $ 1,832 $ 10,848 $ 2,210 $ 380 $ 1,120 $ 290 $ 29,070 Charge-offs — (57 ) — — — (61 ) — — (118 ) Recoveries — 23 — — — 47 — — 70 Provision (752 ) 9 751 53 (24 ) (84 ) (33 ) 155 75 Ending balance at September 30, 2019 $ 300 $ 11,313 $ 2,583 $ 10,901 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,097 Amount of allowance for loan losses loans deemed to be impaired $ — $ 2 $ — $ 86 $ — $ — $ — $ — $ 88 Amount of allowance for loan losses for loans not deemed to be impaired $ 300 $ 11,311 $ 2,583 $ 10,815 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,009 Loans: Ending balance $ 7,824 $ 783,950 $ 121,802 $ 765,385 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,375,661 Loans deemed to be impaired $ — $ 203 $ — $ 2,373 $ — $ — $ — $ — $ 2,576 Loans not deemed to be impaired $ 7,824 $ 783,747 $ 121,802 $ 763,012 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,373,085 Further information pertaining to the allowance for loan losses for the nine months ending September 30, 2019 is as Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at December 31, 2018 $ 1,092 $ 10,998 $ 1,838 $ 10,663 $ 2,190 $ 365 $ 1,111 $ 286 $ 28,543 Charge-offs — (108 ) — — — (228 ) — — (336 ) Recoveries — 49 — — — 141 — — 190 Provision (792 ) 374 745 238 (4 ) 4 (24 ) 159 700 Ending balance at September 30, 2019 $ 300 $ 11,313 $ 2,583 $ 10,901 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,097 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 2 $ — $ 86 $ — $ — $ — $ — $ 88 Amount of allowance for loan losses for loans not deemed to be impaired $ 300 $ 11,311 $ 2,583 $ 10,815 $ 2,186 $ 282 $ 1,087 $ 445 $ 29,009 Loans: Ending balance $ 7,824 $ 783,950 $ 121,802 $ 765,385 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,375,661 Loans deemed to be impaired $ — $ 203 $ — $ 2,373 $ — $ — $ — $ — $ 2,576 Loans not deemed to be impaired $ 7,824 $ 783,747 $ 121,802 $ 763,012 $ 364,317 $ 21,748 $ 310,635 $ — $ 2,373,085 Further information pertaining to the allowance for loan losses for the three months ending September 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at June 30, 2018 $ 633 $ 10,384 $ 1,704 $ 10,209 $ 2,493 $ 336 $ 1,078 $ 307 $ 27,144 Charge-offs — (11 ) — — — (78 ) — — (89 ) Recoveries 1,432 16 — — — 42 — — 1,490 Provision (1,155 ) 895 84 415 (182 ) 32 (28 ) (61 ) — Ending balance at September 30, 2018 $ 910 $ 11,284 $ 1,788 $ 10,624 $ 2,311 $ 332 $ 1,050 $ 246 $ 28,545 Amount of allowance for loan losses $ — $ 93 $ — $ 95 $ 350 $ — $ — $ — $ 538 Amount of allowance for loan losses $ 910 $ 11,191 $ 1,788 $ 10,529 $ 1,961 $ 332 $ 1,050 $ 246 $ 28,007 Loans: Ending balance $ 12,434 $ 783,960 $ 94,532 $ 730,265 $ 335,114 $ 21,216 $ 283,818 $ — $ 2,261,339 Loans deemed to be impaired $ — $ 660 $ — $ 2,680 $ 2,675 $ — $ — $ — $ 6,015 Loans not deemed to be impaired $ 12,434 $ 783,300 $ 94,532 $ 727,585 $ 332,439 $ 21,216 $ 283,818 $ — $ 2,255,324 Further information pertaining to the allowance for loan losses for the nine months ending September 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at December 31, 2 017 $ 1,645 $ 9,651 $ 1,720 $ 9,728 $ 1,873 $ 373 $ 989 $ 276 $ 26,255 Charge-offs — (16 ) — — — (231 ) — — (247 ) Recoveries 1,432 49 — — — 156 — — 1,637 Provision (2,167 ) 1,600 68 896 438 34 61 (30 ) 900 Ending balance at September 30, 2018 $ 910 $ 11,284 $ 1,788 $ 10,624 $ 2,311 $ 332 $ 1,050 $ 246 $ 28,545 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 93 $ — $ 95 $ 350 $ — $ — $ — $ 538 Amount of allowance for loan losses for loans not deemed to be impaired $ 910 $ 11,191 $ 1,788 $ 10,529 $ 1,961 $ 332 $ 1,050 $ 246 $ 28,007 Loans: Ending balance $ 12,434 $ 783,960 $ 94,532 $ 730,265 $ 335,114 $ 21,216 $ 283,818 $ — $ 2,261,339 Loans deemed to be impaired $ — $ 660 $ — $ 2,680 $ 2,675 $ — $ — $ — $ 6,015 Loans not deemed to be impaired $ 12,434 $ 783,300 $ 94,532 $ 727,585 $ 332,439 $ 21,216 $ 283,818 $ — $ 2,255,324
Loans by Risk Rating	The following table presents the Company’s loans by risk rating at September 30, 2019. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 (Pass) $ 7,824 $ 779,722 $ 121,802 $ 738,459 4 (Monitor) — 4,025 — 24,553 5 (Substandard) — — — — 6 (Doubtful) — — — — Impaired — 203 — 2,373 Total $ 7,824 $ 783,950 $ 121,802 $ 765,385 The following table presents the Company’s loans by risk rating at December 31, 2018. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 (Pass) $ 13,628 $ 757,089 $ 97,290 $ 723,170 4 (Monitor) — 4,135 — 24,542 5 (Substandard) — — — — 6 (Doubtful) — — — — Impaired — 401 — 2,650 Total $ 13,628 $ 761,625 $ 97,290 $ 750,362
Loans by Credit Rating	Credit ratings issued by national organizations were utilized as credit quality indicators as presented in the following table at September 30, 2019 and are included within the total loan portfolio. Commercial Municipal Commercial Total (in thousands) Credit Rating: Aaa – Aa3 $ 497,124 $ 54,495 $ 40,759 $ 592,378 A1 – A3 187,970 7,479 148,735 344,184 Baa1 – Baa3 — 51,133 122,288 173,421 Ba2 — 5,895 — 5,895 Total $ 685,094 $ 119,002 $ 311,782 $ 1,115,878 Credit ratings issued by national organizations were utilized as credit quality indicators as presented in the following table at December 31, 2018. Commercial Municipal Commercial Total (in thousands) Credit Rating: Aaa – Aa3 $ 491,247 $ 54,105 $ 42,790 $ 588,142 A1 – A3 172,472 7,605 151,381 331,458 Baa1 – Baa3 — 26,970 118,197 145,167 Ba2 — 6,810 — 6,810 Total $ 663,719 $ 95,490 $ 312,368 $ 1,071,577
Aging of Past Due Loan Losses	Further information pertaining to the allowance for loan losses at September 30, 2019 follows: Accruing 30-89 Days Non Accruing Total Current Total (in thousands) Construction and land development $ — $ — $ — $ — $ 7,824 $ 7,824 Commercial and industrial 108 19 — 127 783,823 783,950 Municipal — — — — 121,802 121,802 Commercial real estate 155 167 — 322 765,063 765,385 Residential real estate 1,129 334 — 1,463 362,854 364,317 Consumer and overdrafts 15 — — 15 21,733 21,748 Home equity 1,050 546 — 1,596 309,039 310,635 Total $ 2,457 $ 1,066 $ — $ 3,523 $ 2,372,138 $ 2,375,661 Further information pertaining to the allowance for loan losses at December 31, 2018 follows: Accruing 30-89 Days Non Accruing Total Current Total (in thousands) Construction and land development $ — $ — $ — $ — $ 13,628 $ 13,628 Commercial and industrial 187 115 — 302 761,323 761,625 Municipal — — — — 97,290 97,290 Commercial real estate 774 190 — 964 749,398 750,362 Residential real estate 2,554 569 — 3,123 345,127 348,250 Consumer and overdrafts 24 14 — 38 22,045 22,083 Home equity 1,108 425 — 1,533 290,807 292,340 Total $ 4,647 $ 1,313 $ — $ 5,960 $ 2,279,618 $ 2,285,578
Information Pertaining to Impaired Loans	The following is information pertaining to impaired loans for September 30, 2019: Carrying Unpaid Required Average Interest Average Interest (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 87 306 — 89 2 87 6 Municipal — — — — — — — Commercial real estate 167 194 — 729 — 529 — Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 254 $ 500 $ — $ 818 $ 2 $ 616 $ 6 With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 116 116 2 310 2 299 6 Municipal — — — — — — — Commercial real estate 2,206 2,326 86 2,140 23 2,350 67 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 2,322 $ 2,442 $ 88 $ 2,450 $ 25 $ 2,649 $ 73 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 203 422 2 399 4 386 12 Municipal — — — — — — — Commercial real estate 2,373 2,520 86 2,869 23 2,879 67 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 2,576 $ 2,942 $ 88 $ 3,268 $ 27 $ 3,265 $ 79 The following is information pertaining to impaired loans for September 30, 2018: Carrying Unpaid Required Average 9 Interest 9 Average 9 9 Interest 9 9 (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 84 282 — 56 — 47 — Municipal — — — — — — — Commercial real estate 196 219 — 280 — 267 — Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 280 $ 501 $ — $ 336 $ — $ 314 $ — With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 576 593 93 589 5 490 14 Municipal — — — — — — — Commercial real estate 2,484 2,597 95 2,262 24 2,278 71 Residential real estate 2,675 2,675 350 2,675 — 3,136 80 Consumer — — — — — — — Home equity — — — — — — — Total $ 5,735 $ 5,865 $ 538 $ 5,526 $ 29 $ 5,904 $ 165 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 660 875 93 645 5 537 14 Municipal — — — — — — — Commercial real estate 2,680 2,816 95 2,542 24 2,545 71 Residential real estate 2,675 2,675 350 2,675 — 3,136 80 Consumer — — — — — — — Home equity — — — — — — — Total $ 6,015 $ 6,366 $ 538 $ 5,862 $ 29 $ 6,218 $ 165

Reclassifications Out of Accu_2

Reclassifications Out of Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Reclassifications Out of Accumulated Other Comprehensive Income	Amount Reclassified from Accumulated Other Comprehensive Income Details about Accumulated Other Comprehensive Income Components Three Three Affected Line Item in the Statement where Net Income is Presented (in thousands) Unrealized gains and losses on available-for-sale securities $ 54 $ 105 Net gains on sales of Tax (expense) or benefit (15 ) (29 ) Provision for income taxes Net of tax $ 39 $ 76 Net income Accretion of unrealized losses transferred $ (209 ) $ (323 ) Interest on securities Tax (expense) or benefit 54 85 Provision for income taxes Net of tax $ (155 ) $ (238 ) Net income Amortization of defined benefit pension items Prior-service costs $ (29 ) $ (4 )(b) Salaries and employee benefits Actuarial gains (losses) (337 ) (402 )(b) Salaries and employee benefits Total before tax (366 ) (406 ) Income before taxes Tax (expense) or benefit 103 114 Provision for income taxes Net of tax $ (263 ) $ (292 ) Net income Details about Accumulated Other Comprehensive Income Components Nine Nine Affected Line Item in the Statement where Net Income is Presented (in thousands) Unrealized gains and losses on available-for-sale securities $ 61 $ 302 Net gains on sales of Tax (expense) or benefit (17 ) (85 ) Provision for income taxes Net of tax $ 44 $ 217 Net income Accretion of unrealized losses transferred $ (779 ) $ (1,186 ) Interest on securities Tax (expense) or benefit 205 314 Provision for income taxes Net of tax $ (574 ) $ (872 ) Net income Amortization of defined benefit pension items Prior-service costs $ (86 ) $ (12 ) ( b Salaries and employee benefits Actuarial gains (losses) (1,013 ) (1,207 ) ( b Salaries and employee benefits Total before tax (1,099 ) (1,219 ) Income before taxes Tax (expense) or benefit 309 342 Provision for income taxes Net of tax $ (790 ) $ (877 ) Net income (a) Amount in parentheses indicates reductions to net income. (b) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Employee Benefits footnote (Note 8) for additional details).

Earnings per share ("EPS") (Tab

Earnings per share ("EPS") (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Reconciliation of Basic EPS and Diluted EPS	The following table is a reconciliation of basic EPS and diluted EPS. Three Months Ended Nine Months Ended (in thousands except share and per share data) 2019 2018 2019 2018 Basic EPS Computation: Numerator: Net income, Class A $ 7,986 $ 7,535 $ 22,849 $ 20,674 Net income, Class B 2,098 2,046 6,118 5,614 Denominator: Weighted average shares outstanding, Class A 3,650,449 3,608,329 3,627,076 3,608,129 Weighted average shares outstanding, Class B 1,917,460 1,959,580 1,940,833 1,959,780 Basic EPS, Class A $ 2.19 $ 2.09 $ 6.30 $ 5.73 Basic EPS, Class B 1.09 1.04 3.15 2.86 Diluted EPS Computation: Numerator: Net income, Class A $ 7,986 $ 7,535 $ 22,849 $ 20,674 Net income, Class B 2,098 2,046 6,118 5,614 Total net income, for diluted EPS, Class A computation 10,084 9,581 28,967 26,288 Denominator: Weighted average shares outstanding, basic, Class A 3,650,449 3,608,329 3,627,076 3,608,129 Weighted average shares outstanding, Class B 1,917,460 1,959,580 1,940,833 1,959,780 Weighted average shares outstanding diluted, Class A 5,567,909 5,567,909 5,567,909 5,567,909 Weighted average shares outstanding, Class B 1,917,460 1,959,580 1,940,833 1,959,780 Diluted EPS, Class A $ 1.81 $ 1.72 $ 5.20 $ 4.72 Diluted EPS, Class B 1.09 1.04 3.15 2.86

Employee Benefits (Tables)

Employee Benefits (Tables)	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost	Components of Net Periodic Benefit Cost for the Three Months Ended September 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 276 $ 353 $ 256 $ 277 Interest 473 371 482 346 Expected return on plan assets (819 ) (954 ) — — Recognized prior service cost (benefit) — (25 ) 28 29 Recognized net actuarial losses 229 226 109 176 Net periodic benefit cost (credit) $ 159 $ (29 ) $ 875 $ 828 Components of Net Periodic Benefit Cost for the Nine Months Ended September 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 828 $ 1,059 $ 768 $ 831 Interest 1,419 1,111 1,445 1,040 Expected return on plan assets (2,457 ) (2,863 ) — — Recognized prior service cost (benefit) — (75 ) 86 87 Recognized net actuarial losses 687 680 326 527 Net periodic benefit cost (credit) $ 477 $ (88 ) $ 2,625 $ 2,485

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Financial Instruments Measured at Fair Value on a Recurring and Non-recurring Basis	The results of the fair value hierarchy as of September 30, 2019, are as follows: Financial Instruments Measured at Fair Value on a Recurring Basis: Securities AFS Fair Value Measurements Using Carrying Quoted Prices Significant Significant (in thousands) SBA Backed Securities $ 58,664 $ — $ 58,664 $ — U.S. Government Agency and Sponsored Mortgage-Backed Securities 170,282 — 170,282 — Privately Issued Residential Mortgage- 579 — 579 — Obligations Issued by States and Political Subdivisions 28,576 — 4,775 23,801 Other Debt Securities 3,638 — 3,638 — Total $ 261,739 $ — $ 237,938 $ 23,801 Equity Securities $ 1,672 $ 324 $ 1,348 $ — Financial Instruments Measured at Fair Value on a Non-recurring Basis: Impaired Loans $ 173 $ — $ — $ 173 Financial Instruments Measured at Fair Value on a Recurring Basis: Securities AFS Fair Value Measurements Using Carrying Quoted Prices Significant Significant (in thousands) U.S. Treasury $ 1,992 $ — $ 1,992 $ — U.S. Government Sponsored Enterprises 3,915 — 3,915 — SBA Backed Securities 70,194 — 70,194 — U.S. Government Agency and Sponsored Mortgage-Backed Securities 162,890 — 162,890 — Privately Issued Residential Mortgage- 672 — 672 — Obligations Issued by States and Political Subdivisions 93,503 — 4,775 88,728 Other Debt Securities 3,593 3,593 Total $ 336,759 $ — $ 248,031 $ 88,728 Equity Securities $ 1,596 $ 293 $ 1,303 $ — Financial Instruments Measured at Fair Value on a Non-recurring Basis: Other Real Estate Owned $ 2,225 $ — $ — $ 2,225 Impaired Loans $ 251 $ — $ — $ 251
Assets Measured at Fair Value	The following table presents additional information about assets measured at fair value on a recurring and nonrecurring basis for which the Company has utilized Level 3 inputs to determine fair value (dollars in thousands). Management continues to monitor the assumptions used to value the assets listed below. Asset Fair Value Valuation Technique Unobservable Input Unobservable Input Securities AFS (4) $ 23,801 Discounted cash flow Discount rate 1.7%-3.1% (3) Impaired Loans $ 173 Appraisal of collateral (1) Appraisal adjustments (2) 0%-30% discount (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated expenses. (3) Weighted averages. (4) Municipal securities generally have maturities of one year or less and, therefore, the amortized cost equates to the fair value. The following table presents additional information about assets measured at fair value on a recurring and nonrecurring basis for which the Company has utilized Level 3 inputs to determine fair value (dollars in thousands). Management continues to monitor the assumptions used to value the assets listed below. Asset Fair Value Valuation Technique Unobservable Input Unobservable Input Securities AFS (4) $ 88,728 Discounted cash flow Discount rate 2.1%-4.1% (3) Other Real Estate Owned $ 2,225 Appraisal of collateral (1) Appraisal adjustments (2) 30% discount Impaired Loans $ 251 Appraisal of collateral (1) Appraisal adjustments (2) 0%-30% discount (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various Level 3 inputs which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated expenses. (3) Weighted averages. (4) Municipal securities generally have maturities of one year or less and, therefore, the amortized cost equates to the fair value.
Changes in Level 3 Securities	The changes in Level 3 securities for the nine month period ended September 30, 2019 are shown in the table below: Obligations (in thousands) Balance at December 31, 2018 $ 88,728 Purchases 13,290 Maturities and calls (78,196 ) Amortization (21 ) Balance at September 30, 2019 $ 23,801 Auction Rate Obligations Total (in thousands) Balance at December 31, 2017 $ 4,459 $ 78,141 $ 82,600 Purchases — 105,837 105,837 Maturities and calls — (72,640 ) (72,640 ) Transfer to Level 2 (4,459 ) — (4,459 ) Amortization — (104 ) (104 ) Changes in fair value — — — Balance at September 30, 2018 $ — $ 111,234 $ 111,234

Fair Values of Financial Inst_2

Fair Values of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Investments, All Other Investments [Abstract]
Carrying Amounts and Fair Values of Company's Financial Instruments	The following presents (in thousands) the carrying amount, estimated fair value, and placement in the fair value hierarchy of the Company’s financial instruments as of September 30, 2019 and December 31, 2018. 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, short-term investments, FHLBB stock and accrued interest receivable. Financial liabilities for which the fair value approximates carrying value include non-maturity deposits, short-term borrowings and accrued interest payable. September 30, 2019 Carrying Estimated Fair Value Level 2 Level 3 (in thousands) Financial assets: Securities held-to-maturity $ 2,164,135 $ 2,188,465 $ — $ 2,188,465 $ — Loans (1) 2,346,564 2,398,515 — — 2,398,515 Financial liabilities: Time deposits 533,074 532,135 — 532,135 — Other borrowed funds 209,188 209,263 — 209,263 — Subordinated debentures 36,083 36,083 — 36,083 — December 31, 2018 Financial assets: Securities held-to-maturity $ 2,046,647 $ 1,991,421 $ — $ 1,991,421 $ — Loans (1) 2,257,035 2,279,712 — — 2,279,712 Financial liabilities: Time deposits 560,579 559,988 — 559,988 — Other borrowed funds 202,378 203,122 — 203,122 — Subordinated debentures 36,083 36,083 — 36,083 — (1) Comprised of loans (including collateral dependent impaired loans), net of deferred loan costs and the allowance for loan losses.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Schedule of Revenue From Contracts	The following table presents total revenues as presented in the Consolidated Statements of Income and the related amounts which are from contracts with customers within the scope of Topic 606. As illustrated here, the vast majority of our revenues are specifically excluded from the scope of Topic 606. Nine Revenue from Nine Revenue from (dollars in thousands) Net $ 70,458 $ — $ 68,871 $ — Noninterest income: Service charges on deposit accounts 6,801 6,801 6,268 6,268 Lockbox fees 3,018 3,018 2,304 2,304 Net gains on sales of securities 61 — 302 — Gains on sales of mortgage loans 154 — — — Other income 3,676 2,338 3,210 2,215 Total noninterest income 13,710 12,157 12,084 10,787 Total reven ues $ 84,168 $ 12,157 $ 80,955 $ 10,787 Three Revenue from Three Revenue from (dollars in thousands) Net $ 23,770 $ — $ 23,204 $ — Noninterest income: Service charges on deposit accounts 2,310 2,310 2,137 2,137 Lockbox fees 937 937 892 892 Net gains on sales of securities 53 — 105 — Gains on sales of mortgage loans — — — — Other income 986 728 1,035 751 Total noninterest income 4,286 3,975 4,169 3,780 Total revenues $ 28,056 $ 3,975 $ 27,373 $ 3,780
Information about Receivables with Customers	The following table provides information about receivables with customers. September 30, 2019 December 31, 2018 (dollars in thousands) Receivables, which are included in “Other assets” $ 1,142 $ 1,205

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Components of lease expense	The components of lease expense were as follows: Three Months Nine Months (in thousands) Operating lease cost $ 550 $ 1,676 Variable lease cost 121 405 Total lease cost $ 671 $ 2,081
Supplemental cash flow information related to leases	Supplemental cash flow information related to leases was as follows: Three Months Nine Months (in thousands) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 528 $ 1,605 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 433 $ 1,318
Supplemental balance sheet information related to leases	Supplemental balance sheet information related to leases was as follows: 9/30/2019 (in thousands, except lease term and discount rate) Operating Leases: Operating lease right-of-use assets $ 12,944 Operating lease liabilities $ 13,101 Weighted Average Remaining Lease Term: Operating Leases 11 Weighted Average Discount Rate: Operating Leases 3.5 %
Maturities of lease liabilities	A summary of future minimum rental payments under such leases as the dates indicated follows: Minimum Rental Payments September 30, 2019 December 31, 2018 (in thousands) Year Ending December 31, 2019 $ 459 $ 2,490 2020 2,038 2,170 2021 1,759 1,694 2022 1,603 1,331 2023 1,541 1,104 Thereafter 8,570 1,074 Total lease payments $ 15,970 $ 9,863 Less imputed interest (2,869 ) Present value of lease liability $ 13,101

Basis of Financial Statement _2

Basis of Financial Statement Presentation - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2019Segment
Number of Reportable Segments	1
Century Bancorp Capital Trust II [Member]
Equity ownership interest	100.00%

Recent Accounting Development_2

Recent Accounting Developments - Additional Information (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Operating Lease, Right-of-Use Asset	$ 12,944
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset	$ 15,100

Securities Available-for-Sale -

Securities Available-for-Sale - Summary of Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 261,939	$ 336,751
Gross Unrealized Gains	367	635
Gross Unrealized Losses	567	627
Total, Fair Value	261,739	336,759
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,000
Gross Unrealized Losses		8
Total, Fair Value		1,992
U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		3,946
Gross Unrealized Losses		31
Total, Fair Value		3,915
SBA Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	58,714	70,477
Gross Unrealized Gains	51	1
Gross Unrealized Losses	101	284
Total, Fair Value	58,664	70,194
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	170,532	162,604
Gross Unrealized Gains	189	536
Gross Unrealized Losses	439	250
Total, Fair Value	170,282	162,890
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	574	679
Gross Unrealized Gains	6	3
Gross Unrealized Losses	1	10
Total, Fair Value	579	672
Obligations Issued by States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	28,519	93,445
Gross Unrealized Gains	57	58
Total, Fair Value	28,576	93,503
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,600	3,600
Gross Unrealized Gains	64	37
Gross Unrealized Losses	26	44
Total, Fair Value	$ 3,638	$ 3,593

Securities Available-for-Sale_2

Securities Available-for-Sale - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)Security	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)Security	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)Security
Schedule of Available-for-sale Securities [Line Items]
Securities at fair value pledged to secure public deposits and repurchase agreements	$ 1,692,033,000		$ 1,692,033,000		$ 1,441,059,000
Securities available-for-sale are securities at fair value pledged for borrowing	32,590,000		32,590,000		$ 34,787,000
Gross gains on sales of securities	53,000	$ 105,000	61,000	$ 302,000
Proceeds from sales of securities available-for-sale			16,285,000	$ 27,517,000
Securities at floating rate or adjustable rate	$ 234,949,000		234,949,000
Federal Home Loan Bank [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross gains on sales of securities			$ 13,000
Securities AFS [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted average remaining life of investment securities available-for-sale			5 years 1 month 6 days
Number of securities, temporarily impaired for less than 12 months | Security	24		24		10
Number of securities, temporarily impaired for 12 months or longer | Security	18		18		30
Number of securities, temporarily impaired, total | Security	134		134		190
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities at fair value pledged to secure public deposits and repurchase agreements	$ 196,356,000		$ 196,356,000		$ 197,304,000

Securities Available-for-Sale_3

Securities Available-for-Sale - Estimated Maturity Distribution of Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Within one year, Amortized Cost	$ 26,187
After one but within five years, Amortized Cost	134,881
After five but within ten years, Amortized Cost	85,551
More than ten years, Amortized Cost	15,320
Amortized Cost	261,939	$ 336,751
Within one year, Fair Value	26,184
After one but within five years, Fair Value	134,811
After five but within ten years, Fair Value	85,378
More than ten years, Fair Value	15,366
Total, Fair Value	$ 261,739	$ 336,759

Securities Available-for-Sale_4

Securities Available-for-Sale - Continuous Unrealized Loss Position for 12 Months or Less and 12 Months and Longer (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 93,238	$ 41,108
Less Than 12 Months, Unrealized Losses	276	80
12 Months or Longer, Fair Value	53,573	93,047
12 Months or Longer, Unrealized Losses	291	547
Total, Fair Value	146,811	134,155
Total, Unrealized Losses	567	627
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value		1,992
12 Months or Longer, Unrealized Losses		8
Total, Fair Value		1,992
Total, Unrealized Losses		8
U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value		3,914
Less Than 12 Months, Unrealized Losses		31
Total, Fair Value		3,914
Total, Unrealized Losses		31
SBA Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	11,133	17,950
Less Than 12 Months, Unrealized Losses	11	28
12 Months or Longer, Fair Value	24,944	44,323
12 Months or Longer, Unrealized Losses	90	256
Total, Fair Value	36,077	62,273
Total, Unrealized Losses	101	284
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	81,305	19,244
Less Than 12 Months, Unrealized Losses	264	21
12 Months or Longer, Fair Value	27,872	45,782
12 Months or Longer, Unrealized Losses	175	229
Total, Fair Value	109,177	65,026
Total, Unrealized Losses	439	250
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	282	495
12 Months or Longer, Unrealized Losses	1	10
Total, Fair Value	282	495
Total, Unrealized Losses	1	10
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	800
Less Than 12 Months, Unrealized Losses	1
12 Months or Longer, Fair Value	475	455
12 Months or Longer, Unrealized Losses	25	44
Total, Fair Value	1,275	455
Total, Unrealized Losses	$ 26	$ 44

Investment Securities Held-to_3

Investment Securities Held-to-Maturity - Summary of Held-to-Maturity Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 2,164,135	$ 2,046,647
Gross Unrealized Gains	31,016	2,660
Gross Unrealized Losses	6,686	57,886
Estimated Fair Value	2,188,465	1,991,421
U.S. Treasury [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost		9,960
Gross Unrealized Losses		2
Estimated Fair Value		9,958
U.S. Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	121,516	234,228
Gross Unrealized Gains	653	336
Gross Unrealized Losses	67	803
Estimated Fair Value	122,102	233,761
SBA Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	47,126	52,051
Gross Unrealized Gains	452
Gross Unrealized Losses	66	2,065
Estimated Fair Value	47,512	49,986
Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1,995,493	1,750,408
Gross Unrealized Gains	29,911	2,324
Gross Unrealized Losses	6,553	55,016
Estimated Fair Value	$ 2,018,851	$ 1,697,716

Investment Securities Held-to_4

Investment Securities Held-to-Maturity - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2019USD ($)Security	Dec. 31, 2018USD ($)Security
Schedule of Held-to-maturity Securities [Line Items]
Securities at fair value pledged to secure public deposits and repurchase agreements	$ 1,692,033,000	$ 1,441,059,000
Securities held to maturity at floating rate or adjustable rate	111,000
Sales of held-to-maturity securities	1,194,000
Commercial Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Gross realised gains on sale of held to maturity securities	48,000
Sales of held-to-maturity securities	$ 1,194,000
Held-to-Maturity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Weighted average remaining life of investment securities held-to-maturity	3 years 7 months 6 days
Number of securities, temporarily impaired for less than 12 months | Security	44	56
Number of securities, temporarily impaired for 12 months or longer | Security	112	315
Number of securities, temporarily impaired, total | Security	505	475
Held-to-Maturity Securities [Member] | U.S. Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Weighted average remaining life	$ 66,196,000
Federal Home Loan Bank [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities pledged for borrowing at the Federal Home Loan Bank	$ 427,425,000	$ 291,190,000

Investment Securities Held-to_5

Investment Securities Held-to-Maturity - Company's Securities Held-to-Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Within one year, Amortized Cost	$ 70,980
After one but within five years, Amortized Cost	1,809,564
After five but within ten years, Amortized Cost	271,068
More than ten years, Amortized Cost	12,523
Amortized Cost	2,164,135	$ 2,046,647
Within one year, Fair Value	71,260
After one but within five years, Fair Value	1,829,087
After five but within ten years, Fair Value	275,192
More than ten years, Fair Value	12,926
Estimated Fair Value	$ 2,188,465	$ 1,991,421

Investment Securities Held-to_6

Investment Securities Held-to-Maturity - Unrealized Market Loss of Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Less Than 12 Months, Fair Value	$ 187,538	$ 207,932
Less Than 12 Months, Unrealized Losses	904	2,076
12 Months or Longer, Fair Value	440,668	1,369,175
12 Months or Longer, Unrealized Losses	5,782	55,810
Total, Fair Value	628,206	1,577,107
Total, Unrealized Losses	6,686	57,886
U.S. Treasury [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less Than 12 Months, Fair Value		9,958
Less Than 12 Months, Unrealized Losses		2
Total, Fair Value		9,958
Total, Unrealized Losses		2
U.S. Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less Than 12 Months, Fair Value	9,976	9,849
Less Than 12 Months, Unrealized Losses	22	42
12 Months or Longer, Fair Value	9,954	69,499
12 Months or Longer, Unrealized Losses	45	761
Total, Fair Value	19,930	79,348
Total, Unrealized Losses	67	803
SBA Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less Than 12 Months, Fair Value	13,673
Less Than 12 Months, Unrealized Losses	66
12 Months or Longer, Fair Value		49,987
12 Months or Longer, Unrealized Losses		2,065
Total, Fair Value	13,673	49,987
Total, Unrealized Losses	66	2,065
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Less Than 12 Months, Fair Value	163,889	188,125
Less Than 12 Months, Unrealized Losses	816	2,032
12 Months or Longer, Fair Value	430,714	1,249,689
12 Months or Longer, Unrealized Losses	5,737	52,984
Total, Fair Value	594,603	1,437,814
Total, Unrealized Losses	$ 6,553	$ 55,016

Allowance for Loan Losses - Ana

Allowance for Loan Losses - Analysis of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Receivables [Abstract]
Allowance for loan losses, beginning of year	$ 29,070	$ 27,144	$ 28,543	$ 26,255
Loans charged-off	(118)	(89)	(336)	(247)
Recoveries on loans previously charged-off	70	1,490	190	1,637
Net recoveries (charge-offs)	(48)	1,401	(146)	1,390
Provision charged to expense	75		700	900
Allowance for loan losses, end of year	$ 29,097	$ 28,545	$ 29,097	$ 28,545

Allowance for Loan Losses - Sum

Allowance for Loan Losses - Summary of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	$ 29,070	$ 27,144		$ 28,543	$ 26,255
Charge-offs	(118)	(89)		(336)	(247)
Recoveries	70	1,490		190	1,637
Provision	75			700	900
Allowance for loan losses, end of year	29,097	28,545	$ 27,144	29,097	28,545
Amount of allowance for loan losses for loans deemed to be impaired	88	538		88	538
Amount of allowance for loan losses for loans not deemed to be impaired	29,009	28,007		29,009	28,007
Loans:
Total loans, net	2,375,661	2,261,339		2,375,661	2,261,339	$ 2,285,578
Loans deemed to be impaired	2,576	6,015		2,576	6,015
Loans not deemed to be impaired	2,373,085	2,255,324		2,373,085	2,255,324
Construction and Land Development [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	1,052	633		1,092	1,645
Recoveries		1,432			1,432
Provision	(752)	(1,155)		(792)	(2,167)
Allowance for loan losses, end of year	300	910	633	300	910
Amount of allowance for loan losses for loans not deemed to be impaired	300	910		300	910
Loans:
Total loans, net	7,824	12,434		7,824	12,434	13,628
Loans not deemed to be impaired	7,824	12,434		7,824	12,434
Commercial and Industrial [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	11,338	10,384		10,998	9,651
Charge-offs	(57)	(11)		(108)	(16)
Recoveries	23	16		49	49
Provision	9	895		374	1,600
Allowance for loan losses, end of year	11,313	11,284	10,384	11,313	11,284
Amount of allowance for loan losses for loans deemed to be impaired	2	93		2	93
Amount of allowance for loan losses for loans not deemed to be impaired	11,311	11,191		11,311	11,191
Loans:
Total loans, net	783,950	783,960		783,950	783,960	761,625
Loans deemed to be impaired	203	660		203	660
Loans not deemed to be impaired	783,747	783,300		783,747	783,300
Municipal [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	1,832	1,704		1,838	1,720
Provision	751	84		745	68
Allowance for loan losses, end of year	2,583	1,788	1,704	2,583	1,788
Amount of allowance for loan losses for loans not deemed to be impaired	2,583	1,788		2,583	1,788
Loans:
Total loans, net	121,802	94,532		121,802	94,532	97,290
Loans not deemed to be impaired	121,802	94,532		121,802	94,532
Commercial Real Estate [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	10,848	10,209		10,663	9,728
Provision	53	415		238	896
Allowance for loan losses, end of year	10,901	10,624	10,209	10,901	10,624
Amount of allowance for loan losses for loans deemed to be impaired	86	95		86	95
Amount of allowance for loan losses for loans not deemed to be impaired	10,815	10,529		10,815	10,529
Loans:
Total loans, net	765,385	730,265		765,385	730,265	750,362
Loans deemed to be impaired	2,373	2,680		2,373	2,680
Loans not deemed to be impaired	763,012	727,585		763,012	727,585
Residential Real Estate [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	2,210	2,493		2,190	1,873
Provision	(24)	(182)		(4)	438
Allowance for loan losses, end of year	2,186	2,311	2,493	2,186	2,311
Amount of allowance for loan losses for loans deemed to be impaired		350			350
Amount of allowance for loan losses for loans not deemed to be impaired	2,186	1,961		2,186	1,961
Loans:
Total loans, net	364,317	335,114		364,317	335,114	348,250
Loans deemed to be impaired		2,675			2,675
Loans not deemed to be impaired	364,317	332,439		364,317	332,439
Consumer [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	380	336		365	373
Charge-offs	(61)	(78)		(228)	(231)
Recoveries	47	42		141	156
Provision	(84)	32		4	34
Allowance for loan losses, end of year	282	332	336	282	332
Amount of allowance for loan losses for loans not deemed to be impaired	282	332		282	332
Loans:
Total loans, net	21,748	21,216		21,748	21,216	22,083
Loans not deemed to be impaired	21,748	21,216		21,748	21,216
Home Equity [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	1,120	1,078		1,111	989
Provision	(33)	(28)		(24)	61
Allowance for loan losses, end of year	1,087	1,050	1,078	1,087	1,050
Amount of allowance for loan losses for loans not deemed to be impaired	1,087	1,050		1,087	1,050
Loans:
Total loans, net	310,635	283,818		310,635	283,818	$ 292,340
Loans not deemed to be impaired	310,635	283,818		310,635	283,818
Unallocated [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	290	307		286	276
Provision	155	(61)		159	(30)
Allowance for loan losses, end of year	445	$ 246	307	445	246
Amount of allowance for loan losses for loans not deemed to be impaired	445		$ 246	445	$ 246
Loans:
Total loans, net	$ 2,375,661			$ 2,375,661

Allowance for Loan Losses - Loa

Allowance for Loan Losses - Loans by Risk Rating (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Loans by risk rating
Financing Receivable, Net	$ 2,375,661	$ 2,285,578	$ 2,261,339
Construction and Land Development [Member]
Loans by risk rating
Financing Receivable, Net	7,824	13,628	12,434
Commercial and Industrial [Member]
Loans by risk rating
Financing Receivable, Net	783,950	761,625	783,960
Municipal [Member]
Loans by risk rating
Financing Receivable, Net	121,802	97,290	94,532
Commercial Real Estate [Member]
Loans by risk rating
Financing Receivable, Net	765,385	750,362	$ 730,265
1-3 (Pass) [Member] | Construction and Land Development [Member]
Loans by risk rating
Financing Receivable, Net	7,824	13,628
1-3 (Pass) [Member] | Commercial and Industrial [Member]
Loans by risk rating
Financing Receivable, Net	779,722	757,089
1-3 (Pass) [Member] | Municipal [Member]
Loans by risk rating
Financing Receivable, Net	121,802	97,290
1-3 (Pass) [Member] | Commercial Real Estate [Member]
Loans by risk rating
Financing Receivable, Net	738,459	723,170
4 (Monitor) [Member] | Commercial and Industrial [Member]
Loans by risk rating
Financing Receivable, Net	4,025	4,135
4 (Monitor) [Member] | Commercial Real Estate [Member]
Loans by risk rating
Financing Receivable, Net	24,553	24,542
Impaired [Member] | Commercial and Industrial [Member]
Loans by risk rating
Financing Receivable, Net	203	401
Impaired [Member] | Commercial Real Estate [Member]
Loans by risk rating
Financing Receivable, Net	$ 2,373	$ 2,650

Allowance for Loan Losses - L_2

Allowance for Loan Losses - Loans by Credit Rating (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	$ 1,115,878	$ 1,071,577
Aaa - Aa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	592,378	588,142
A1 - A3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	344,184	331,458
Baa1 - Baa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	173,421	145,167
Ba2 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	5,895	6,810
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	685,094	663,719
Commercial and Industrial [Member] | Aaa - Aa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	497,124	491,247
Commercial and Industrial [Member] | A1 - A3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	187,970	172,472
Municipal [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	119,002	95,490
Municipal [Member] | Aaa - Aa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	54,495	54,105
Municipal [Member] | A1 - A3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	7,479	7,605
Municipal [Member] | Baa1 - Baa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	51,133	26,970
Municipal [Member] | Ba2 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	5,895	6,810
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	311,782	312,368
Commercial Real Estate [Member] | Aaa - Aa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	40,759	42,790
Commercial Real Estate [Member] | A1 - A3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	148,735	151,381
Commercial Real Estate [Member] | Baa1 - Baa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	$ 122,288	$ 118,197

Allowance for Loan Losses - Agi

Allowance for Loan Losses - Aging of Past Due Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	$ 2,457	$ 4,647
Non Accrual	1,066	1,313
Total Past Due	3,523	5,960
Current Loans	2,372,138	2,279,618
Total loans, net	2,375,661	2,285,578	$ 2,261,339
Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current Loans	7,824	13,628
Total loans, net	7,824	13,628	12,434
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	108	187
Non Accrual	19	115
Total Past Due	127	302
Current Loans	783,823	761,323
Total loans, net	783,950	761,625	783,960
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current Loans	121,802	97,290
Total loans, net	121,802	97,290	94,532
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	155	774
Non Accrual	167	190
Total Past Due	322	964
Current Loans	765,063	749,398
Total loans, net	765,385	750,362	730,265
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	1,129	2,554
Non Accrual	334	569
Total Past Due	1,463	3,123
Current Loans	362,854	345,127
Total loans, net	364,317	348,250	335,114
Consumer and overdrafts [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	15	24
Non Accrual		14
Total Past Due	15	38
Current Loans	21,733	22,045
Total loans, net	21,748	22,083	21,216
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	1,050	1,108
Non Accrual	546	425
Total Past Due	1,596	1,533
Current Loans	309,039	290,807
Total loans, net	$ 310,635	$ 292,340	$ 283,818

Allowance for Loan Losses - Inf

Allowance for Loan Losses - Information Pertaining to Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	$ 254	$ 280	$ 254	$ 280
With no required reserve recorded, Unpaid Balance Principal	500	501	500	501
With no required reserve recorded, Average Carrying Value Recognized	818	336	616	314
With no required reserve recorded, Interest Income	2		6
With required reserve recorded, Carrying Value	2,322	5,735	2,322	5,735
With required reserve recorded, Unpaid Balance Principal	2,442	5,865	2,442	5,865
With required reserve recorded, Required Reserve	88	538	88	538
With required reserve recorded, Average Carrying Value Recognized	2,450	5,526	2,649	5,904
With required reserve recorded, Interest Income	25	29	73	165
Carrying Value	2,576	6,015	2,576	6,015
Unpaid Balance Principal	2,942	6,366	2,942	6,366
With required reserve recorded, Required Reserve	88	538	88	538
Average Carrying Value Recognized	3,268		3,265	6,218
Interest Income	27	29	79	165
Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
With no required reserve recorded, Carrying Value		84		84
With no required reserve recorded, Unpaid Balance Principal		282		282
With no required reserve recorded, Average Carrying Value Recognized		56		47
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	87		87
With no required reserve recorded, Unpaid Balance Principal	306		306
With no required reserve recorded, Average Carrying Value Recognized	89		87
With no required reserve recorded, Interest Income	2		6
With required reserve recorded, Carrying Value	116	576	116	576
With required reserve recorded, Unpaid Balance Principal	116	593	116	593
With required reserve recorded, Required Reserve	2	93	2	93
With required reserve recorded, Average Carrying Value Recognized	310	589	299	490
With required reserve recorded, Interest Income	2	5	6	14
Carrying Value	203	660	203	660
Unpaid Balance Principal	422	875	422	875
With required reserve recorded, Required Reserve	2	93	2	93
Average Carrying Value Recognized		645	386	537
Interest Income	4	5	12	14
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Average Carrying Value Recognized	399
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	167	196	167	196
With no required reserve recorded, Unpaid Balance Principal	194	219	194	219
With no required reserve recorded, Average Carrying Value Recognized	729	280	529	267
With required reserve recorded, Carrying Value	2,206	2,484	2,206	2,484
With required reserve recorded, Unpaid Balance Principal	2,326	2,597	2,326	2,597
With required reserve recorded, Required Reserve	86	95	86	95
With required reserve recorded, Average Carrying Value Recognized	2,140	2,262	2,350	2,278
With required reserve recorded, Interest Income	23	24	67	71
Carrying Value	2,373	2,680	2,373	2,680
Unpaid Balance Principal	2,520	2,816	2,520	2,816
With required reserve recorded, Required Reserve	86	95	86	95
Average Carrying Value Recognized	2,869	2,542	2,879	2,545
Interest Income	$ 23	24	$ 67	71
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
With required reserve recorded, Carrying Value		2,675		2,675
With required reserve recorded, Unpaid Balance Principal		2,675		2,675
With required reserve recorded, Required Reserve		350		350
With required reserve recorded, Average Carrying Value Recognized		2,675		3,136
With required reserve recorded, Interest Income				80
Carrying Value		2,675		2,675
Unpaid Balance Principal		2,675		2,675
With required reserve recorded, Required Reserve		350		350
Average Carrying Value Recognized		2,675		3,136
Interest Income				$ 80
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Average Carrying Value Recognized		$ 5,862

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2019USD ($)ContractsContract	Sep. 30, 2018USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Specific reserves	$ 88,000	$ 538,000
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of troubled debt restructurings | Contracts	1
Post-modification outstanding recorded investment		2,675,000
Specific reserves		350,000
Troubled debt restructurings, subsequently defaulted		$ 2,675,000
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of troubled debt restructurings | Contract	1
Pre-modification outstanding recorded investment	$ 17,000
Post-modification outstanding recorded investment	17,000
Specific reserves	$ 1,000

Reclassifications Out of Accu_3

Reclassifications Out of Accumulated Other Comprehensive Income - Reclassifications Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net gains on sales of securities	$ 53	$ 105	$ 61	$ 302
Provision for income taxes	(435)	(444)	(584)	(1,259)
Net income	10,084	9,581	28,967	26,288
Salaries and employee benefits	(10,670)	(10,570)	(32,621)	(32,331)
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net gains on sales of securities	54	105	61	302
Provision for income taxes	(15)	(29)	(17)	(85)
Net income	39	76	44	217
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Accretion of Unrealized Losses Transferred [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net gains on sales of securities	(209)	(323)	(779)	(1,186)
Provision for income taxes	54	85	205	314
Net income	(155)	(238)	(574)	(872)
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Prior-Service Costs [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and employee benefits	(29)	(4)	(86)	(12)
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Actuarial Gains (Losses) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and employee benefits	(337)	(402)	(1,013)	(1,207)
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Amortization of Defined Benefit Pension Items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before taxes	(366)	(406)	(1,099)	(1,219)
Provision for income taxes	103	114	309	342
Net income	$ (263)	$ (292)	$ (790)	$ (877)

Earnings per Share ("EPS") - Ad

Earnings per Share ("EPS") - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2019
Class A Common Stock [Member] | Minimum [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Class A common stock entitled dividend per share percent in comparison to Class B common stock	200.00%

Earnings Per Share ("EPS") - Re

Earnings Per Share ("EPS") - Reconciliation of Basic EPS and Diluted EPS (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 10,084	$ 9,581	$ 28,967	$ 26,288
Class A Common Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 7,986	$ 7,535	$ 22,849	$ 20,674
Weighted average shares outstanding, basic	3,650,449	3,608,329	3,627,076	3,608,129
Basic earnings per share	$ 2.19	$ 2.09	$ 6.30	$ 5.73
Net income	$ 7,986	$ 7,535	$ 22,849	$ 20,674
Weighted average shares outstanding, diluted	5,567,909	5,567,909	5,567,909	5,567,909
Diluted earnings per share	$ 1.81	$ 1.72	$ 5.20	$ 4.72
Class B Common Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 2,098	$ 2,046	$ 6,118	$ 5,614
Weighted average shares outstanding, basic	1,917,460	1,959,580	1,940,833	1,959,780
Basic earnings per share	$ 1.09	$ 1.04	$ 3.15	$ 2.86
Net income	$ 2,098	$ 2,046	$ 6,118	$ 5,614
Weighted average shares outstanding, diluted	1,917,460	1,959,580	1,940,833	1,959,780
Diluted earnings per share	$ 1.09	$ 1.04	$ 3.15	$ 2.86

Employee Benefits - Additional

Employee Benefits - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	$ 0
Accounting Standards Update 2017-07 [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification from salaries and employee benefits to other expenses	$ 1,506,000	$ 507,000

Employee Benefits - Components

Employee Benefits - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Pension Plan [Member]
Components of net periodic benefit cost
Service cost	$ 276	$ 353	$ 828	$ 1,059
Interest cost	473	371	1,419	1,111
Expected return on plan assets	(819)	(954)	(2,457)	(2,863)
Recognized prior service cost		(25)		(75)
Recognized net losses	229	226	687	680
Net periodic benefit cost (credit)	159	(29)	477	(88)
Supplemental Insurance/ Retirement Plan [Member]
Components of net periodic benefit cost
Service cost	256	277	768	831
Interest cost	482	346	1,445	1,040
Recognized prior service cost	28	29	86	87
Recognized net losses	109	176	326	527
Net periodic benefit cost (credit)	$ 875	$ 828	$ 2,625	$ 2,485

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Specific adjustments to impaired loans recognized	$ (204,837)	$ 37,099	$ 540,000
Amortized cost of Level 3 securities	1,635,000	1,635,000	1,635,000
Liabilities measured at fair value on a recurring or nonrecurring basis	0	0	$ 0	$ 0
Unrealized loss				0
Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of loans		(78,000)
Fair Value Measurements, Level 3 Inputs [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized cost of Level 3 securities	23,801,000,000	23,801,000,000		$ 111,234,000,000
Unrealized loss	$ 0	$ 0

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value (Detail) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Fair Value	[1]		$ 88,728
Securities AFS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Fair Value		$ 23,801
Valuation Technique	[1]	Discounted cash flow	Discounted cash flow
Unobservable Input	[1]	Discount rate	Discount rate
Impaired Loans [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Fair Value		$ 173	$ 251
Valuation Technique			Appraisal of collateral
Unobservable Input			Appraisal adjustments
Other Real Estate Owned [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Fair Value			$ 2,225
Valuation Technique		Appraisal of collateral	Appraisal of collateral
Unobservable Input		Appraisal adjustments	Appraisal adjustments
Unobservable Input Value or Range			30.00%
Minimum [Member] | Securities AFS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Securities AFS, Unobservable Input Value or Range		1.7	2.1
Minimum [Member] | Impaired Loans [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Impaired Loans, Unobservable Input Value or Range		0	0
Maximum [Member] | Securities AFS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Securities AFS, Unobservable Input Value or Range		3.1	4.1
Maximum [Member] | Impaired Loans [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Impaired Loans, Unobservable Input Value or Range		30	30
[1]	Municipal securities generally have maturities of one year or less and, therefore, the amortized cost equates to the fair value

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 Securities (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		$ 82,600
Purchases		105,837
Maturities/redemptions		(72,640)
Transfer to Level 2		(4,459)
Amortization		(104)
Ending Balance		111,234
Auction Rate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		4,459
Transfer to Level 2		(4,459)
Obligations Issued by States and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 88,728	78,141
Purchases	13,290	105,837
Maturities/redemptions	(78,196)	(72,640)
Amortization	(21)	(104)
Ending Balance	$ 23,801	$ 111,234

Fair Value Measurements - Finan

Fair Value Measurements - Financial Instruments Measured at Fair Value on a Recurring and Non-recurring Basis (Detail) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		$ 261,739	$ 336,759
Financial Instruments Measured at Fair Value on a Non-recurring Basis Impaired Loans	[1]		88,728
Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		237,938	248,031
Fair Value Measurements, Level 3 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		23,801	88,728
Other Real Estate Owned			2,225
Financial Instruments Measured at Fair Value on a Non-recurring Basis Impaired Loans		173	251
U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS			1,992
U.S. Treasury [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS			1,992
U.S. Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS			3,915
U.S. Government Sponsored Enterprises [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS			3,915
SBA Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		58,664	70,194
SBA Backed Securities [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		58,664	70,194
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		170,282	162,890
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		170,282	162,890
Privately Issued Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		579	672
Privately Issued Residential Mortgage-Backed Securities [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		579	672
Obligations Issued by States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		28,576	93,503
Obligations Issued by States and Political Subdivisions [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		4,775	4,775
Obligations Issued by States and Political Subdivisions [Member] | Fair Value Measurements, Level 3 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		23,801	88,728
Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		3,638	3,593
Other Debt Securities [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		3,638	3,593
Equity Securities [Member] | Fair Value Measurements, Level 1 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments Measured at Fair Value on a Non Recurring Basis Equity Securities		324	293
Equity Securities [Member] | Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments Measured at Fair Value on a Non Recurring Basis Equity Securities		1,348	1,303
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		261,739	336,759
Other Real Estate Owned			2,225
Financial Instruments Measured at Fair Value on a Non-recurring Basis Impaired Loans		173	251
Carrying Value [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS			1,992
Carrying Value [Member] | U.S. Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS			3,915
Carrying Value [Member] | SBA Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		58,664	70,194
Carrying Value [Member] | U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		170,282	162,890
Carrying Value [Member] | Privately Issued Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		579	672
Carrying Value [Member] | Obligations Issued by States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		28,576	93,503
Carrying Value [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS		3,638	3,593
Carrying Value [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Instruments Measured at Fair Value on a Non Recurring Basis Equity Securities		$ 1,672	$ 1,596
[1]	Municipal securities generally have maturities of one year or less and, therefore, the amortized cost equates to the fair value

Fair Values of Financial Inst_3

Fair Values of Financial Instruments - Carrying Amount and Fair Value of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financial assets:
Securities held-to-maturity	$ 2,164,135	$ 2,046,647
Loans	2,346,564	2,257,035
Financial liabilities:
Time deposits	533,074	560,579
Other borrowed funds	209,188	202,378
Subordinated debentures	36,083	36,083
Carrying Value [Member]
Financial assets:
Securities held-to-maturity	2,164,135	2,046,647
Loans	2,346,564	2,257,035	[1]
Financial liabilities:
Time deposits	533,074	560,579
Other borrowed funds	209,188	202,378
Subordinated debentures	36,083	36,083
Estimated Fair Value [Member]
Financial assets:
Securities held-to-maturity	2,188,465	1,991,421
Loans	2,398,515	2,279,712	[1]
Financial liabilities:
Time deposits	532,135	559,988
Other borrowed funds	209,263	203,122
Subordinated debentures	36,083	36,083
Fair Value Measurements, Level 2 Inputs [Member]
Financial assets:
Securities held-to-maturity	2,188,465	1,991,421
Financial liabilities:
Time deposits	532,135	559,988
Other borrowed funds	209,263	203,122
Subordinated debentures	36,083	36,083
Fair Value Measurements, Level 3 Inputs [Member]
Financial assets:
Loans	$ 2,398,515	$ 2,279,712
[1]	Comprised of loans (including collateral dependent impaired loans), net of deferred loan costs and the allowance for loan losses.

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Schedule of Revenue from Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Net interest income	$ 23,770	$ 23,204	$ 70,458	$ 68,871
Noninterest income:
Service charges on deposit accounts	2,310	2,137	6,801	6,268
Lockbox fees	937	892	3,018	2,304
Net gains on sales of securities	53	105	61	302
Gains on sales of mortgage loans	0		154
Other income	986	1,035	3,676	3,210
Total noninterest income	4,286	4,169	13,710	12,084
ASU 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Net interest income	23,770	23,204	70,458	68,871
Noninterest income:
Service charges on deposit accounts	2,310	2,137	6,801	6,268
Lockbox fees	937	892	3,018	2,304
Net gains on sales of securities	53	105	61	302
Gains on sales of mortgage loans			154
Other income	986	1,035	3,676	3,210
Total noninterest income	4,286	4,169	13,710	12,084
Total revenues	28,056	27,373	84,168	80,955
ASU 2014-09 [Member] | Revenue Guidance Contracts in Scope of Topic 606 [Member]
Noninterest income:
Service charges on deposit accounts	2,310	2,137	6,801	6,268
Lockbox fees	937	892	3,018	2,304
Other income	728	751	2,338	2,215
Total noninterest income	3,975	3,780	12,157	10,787
Total revenues	$ 3,975	$ 3,780	$ 12,157	$ 10,787

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Information about Receivables with Customers (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Other Assets [Member]
Disaggregation of Revenue [Line Items]
Receivables, which are included in "Other assets"	$ 1,142	$ 1,205

Leases - Additional Information

Leases - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2019USD ($)
Operating lease option to extend	options to extend the leases for up to 10 years, and some of which include options to terminate the leases within 1 year.
Sublease Income	$ 29,000
Sublease option to terminate	sublease expires in 2022 with an option to terminate and no option to extend.
Maximum [Member]
Operating lease remaining lease term	32 years
Minimum [Member]
Operating lease remaining lease term	1 year

Leases - Components of lease ex

Leases - Components of lease expense (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Operating lease cost	$ 550	$ 1,676
Variable lease cost	121	405
Total lease cost	$ 671	$ 2,081

Leases - Supplemental cash flow

Leases - Supplemental cash flow information related to leases (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 528	$ 1,605
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 433	$ 1,318

Leases - Supplemental balance s

Leases - Supplemental balance sheet information related to leases (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Operating Leases:
Operating lease right-of-use assets, included in other assets	$ 12,944
Operating lease liabilities, included in other liabilities	$ 13,101
Weighted Average Remaining Lease Term:
Operating Leases	11 years
Weighted Average Discount Rate:
Operating Leases	3.50%

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Rental Payments (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Year Ending December 31, 2019	$ 459	$ 2,490
2020	2,038	2,170
2021	1,759	1,694
2022	1,603	1,331
2023	1,541	1,104
Thereafter	8,570	1,074
Total lease payments	15,970	$ 9,863
Less imputed interest	(2,869)
Present value of lease liability	$ 13,101