Century Bancorp (CNBKA) 10-Q 8 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
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	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	Jun. 30, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 69,317	$ 89,540
Federal funds sold and interest-bearing deposits in other banks	181,409	252,963
Total cash and cash equivalents	250,726	342,503
Securities available-for-sale, amortized cost $291,699 and $336,751, respectively	291,402	336,759
Securities held-to-maturity, fair value $2,184,525 and $1,991,421, respectively	2,178,568	2,046,647
Federal Home Loan Bank of Boston, stock at cost	21,139	17,974
Equity securities, amortized cost $1,635 and $1,635, respectively	1,681	1,596
Loans, net:
Construction and land development	13,751	13,628
Commercial and industrial	764,492	761,625
Municipal	95,682	97,290
Commercial real estate	758,242	750,362
Residential real estate	346,585	348,250
Consumer and overdrafts	22,609	22,083
Home equity	311,210	292,340
Total loans, net	2,312,571	2,285,578
Less: allowance for loan losses	29,070	28,543
Net loans	2,283,501	2,257,035
Bank premises and equipment	25,296	23,921
Accrued interest receivable	14,655	14,406
Goodwill	2,714	2,714
Other assets	130,819	120,380
Total assets	5,200,501	5,163,935
Deposits:
Demand deposits	765,127	813,478
Savings and NOW deposits	1,668,802	1,707,019
Money market accounts	1,172,283	1,325,888
Time deposits	489,948	560,579
Total deposits	4,096,160	4,406,964
Securities sold under agreements to repurchase	219,510	154,240
Other borrowed funds	451,419	202,378
Subordinated debentures	36,083	36,083
Due to broker	800
Other liabilities	77,592	63,831
Total liabilities	4,881,564	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	319,270	301,488
Stockholders' equity before adjustment of accumulated other comprehensive income (loss)	337,130	319,348
Unrealized losses on securities available-for-sale, net of taxes	(224)	6
Unrealized losses on securities transferred to held-to-maturity, net of taxes	(2,146)	(2,565)
Pension liability, net of taxes	(15,823)	(16,350)
Total accumulated other comprehensive loss, net of taxes	(18,193)	(18,909)
Total stockholders' equity	318,937	300,439
Total liabilities and stockholders' equity	5,200,501	5,163,935
Class A Common Stock [Member]
Stockholders' Equity
Common stock value	3,620	3,608
Total stockholders' equity	3,622	3,608
Class B Common Stock [Member]
Stockholders' Equity
Common stock value	1,948	1,960
Total stockholders' equity	$ 1,948	$ 1,960

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Amortized cost	$ 291,699	$ 336,751
Held-to-maturity securities, fair value	2,184,525	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	3,620,449	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	1,947,460	1,959,580

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest income
Loans	$ 21,680	$ 19,179	$ 42,989	$ 37,446
Securities held-to-maturity	14,595	11,135	28,383	21,423
Securities available-for-sale	2,490	2,329	5,121	4,321
Federal funds sold and interest-bearing deposits in other banks	927	765	2,276	1,648
Total interest income	39,692	33,408	78,769	64,838
Interest expense
Savings and NOW deposits	5,877	2,583	11,342	4,806
Money market accounts	5,412	2,934	10,756	5,387
Time deposits	2,893	2,531	5,686	4,894
Securities sold under agreements to repurchase	490	188	875	369
Other borrowed funds and subordinated debentures	1,770	1,973	3,422	3,715
Total interest expense	16,442	10,209	32,081	19,171
Net interest income	23,250	23,199	46,688	45,667
Provision for loan losses	250	450	625	900
Net interest income after provision for loan losses	23,000	22,749	46,063	44,767
Other operating income
Service charges on deposit accounts	2,282	2,064	4,491	4,131
Lockbox fees	992	621	2,081	1,412
Net gains on sales of securities	7		7	197
Gains on sales of mortgage loans	139		154
Other income	1,577	1,037	2,691	2,175
Total other operating income	4,997	3,722	9,424	7,915
Operating expenses
Salaries and employee benefits	10,916	10,536	21,951	21,761
Occupancy	1,522	1,461	3,223	3,098
Equipment	795	780	1,578	1,574
FDIC assessments	349	359	722	742
Other	4,682	4,023	8,980	7,985
Total operating expenses	18,264	17,159	36,454	35,160
Income before income taxes	9,733	9,312	19,033	17,522
Provision for income taxes	267	314	149	815
Net income	$ 9,466	$ 8,998	$ 18,884	$ 16,707
Class A Common Stock [Member]
Share data:
Weighted average number of shares outstanding, basic	3,620,449	3,608,029	3,615,389	3,608,029
Weighted average number of shares outstanding, diluted	5,567,909	5,567,909	5,567,909	5,567,909
Basic earnings per share	$ 2.06	$ 1.96	$ 4.11	$ 3.64
Diluted earnings per share	$ 1.70	$ 1.62	$ 3.39	$ 3
Class B Common Stock [Member]
Share data:
Weighted average number of shares outstanding, basic	1,947,460	1,959,880	1,952,520	1,959,880
Weighted average number of shares outstanding, diluted	1,947,460	1,959,880	1,952,520	1,959,880
Basic earnings per share	$ 1.03	$ 0.98	$ 2.06	$ 1.82
Diluted earnings per share	$ 1.03	$ 0.98	$ 2.06	$ 1.82

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 9,466	$ 8,998	$ 18,884	$ 16,707
Unrealized gains (losses) on securities:
Unrealized (losses) gains arising during period	232	288	(235)	501
Less: reclassification adjustment for gains included in net income			5	(142)
Total unrealized (losses) gains on securities	232	288	(230)	359
Accretion of net unrealized losses transferred	203	253	419	634
Defined benefit pension plans:
Amortization of prior service cost and loss included in net periodic benefit cost	264	292	527	585
Other comprehensive income	699	833	716	1,578
Comprehensive income	$ 10,165	$ 9,831	$ 19,600	$ 18,285

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	16,707				16,707
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	359							359
Accretion of net unrealized losses transferred during the period, net of taxes	634							634
Pension liability adjustment, net of taxes	585							585
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		(866)	(235)			$ (866)	$ (235)
Ending balance at Jun. 30, 2018	277,481	3,608	1,960	12,292	283,084			(23,463)
Beginning balance at Mar. 31, 2018	268,200	3,608	1,960	12,292	274,636			(24,296)
Net income	8,998				8,998
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	288							288
Accretion of net unrealized losses transferred during the period, net of taxes	253							253
Pension liability adjustment, net of taxes	292							292
Cash dividends		(433)	(117)			(433)	(117)
Ending balance at Jun. 30, 2018	277,481	3,608	1,960	12,292	283,084			(23,463)
Beginning balance at Dec. 31, 2018	300,439	3,608	1,960	12,292	301,488			(18,909)
Net income	18,884				18,884
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	(230)							(230)
Accretion of net unrealized losses transferred during the period, net of taxes	419							419
Pension liability adjustment, net of taxes	527							527
Conversion of Class B Common Stock to Class A Common Stock		12	(12)
Cash dividends		(867)	(235)			(867)	(235)
Ending balance at Jun. 30, 2019	318,937	3,622	1,948	12,292	319,270			(18,193)
Beginning balance at Mar. 31, 2019	309,324	3,610	1,958	12,292	310,356			(18,892)
Net income	9,466				9,466			0
Other comprehensive income, net of tax:
Unrealized holding gains arising during period, net of taxes	232							232
Accretion of net unrealized losses transferred during the period, net of taxes	203							203
Pension liability adjustment, net of taxes	264							264
Conversion of Class B Common Stock to Class A Common Stock		12	(12)
Cash dividends		(435)	(117)			$ (435)	$ (117)
Ending balance at Jun. 30, 2019	$ 318,937	$ 3,622	$ 1,948	$ 12,292	$ 319,270			$ (18,193)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Unrealized holding gains arising during period, taxes	$ 92	$ 91	$ 75	$ 100
Realized net gains	7			197
Accretion of net unrealized losses transferred during the period, taxes	73	90	151	229
Pension liability adjustment, taxes	$ 103	$ 114	$ 206	$ 228
Class A Common Stock [Member]
Conversion of Class B Common Stock to Class A Common Stock, shares	12,120		12,120	2,200
Cash dividends, per share	$ 0.12	$ 0.12	$ 0.24	$ 0.24
Class B Common Stock [Member]
Conversion of Class B Common Stock to Class A Common Stock, shares	12,120		12,120	2,200
Cash dividends, per share	$ 0.06	$ 0.06	$ 0.12	$ 0.12

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 18,884	$ 16,707
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	(7)	(197)
Net (gain) loss on equity securities	(85)	22
Provision for loan losses	625	900
Deferred income taxes	(351)	(986)
Net depreciation and amortization	(1,051)	934
Increase in accrued interest receivable	(249)	(1,494)
(Increase) decrease in other assets	(1,192)	1,023
Increase in other liabilities	138	3,100
Net cash provided by operating activities	16,558	20,009
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from redemptions of Federal Home Loan Bank of Boston stock	5,558	4,024
Purchase of Federal Home Loan Bank of Boston stock	(8,723)	(10,257)
Proceeds from calls/maturities of securities available-for-sale	86,367	70,526
Proceeds from sales of securities available-for-sale	12,330	17,871
Purchase of securities available-for-sale	(52,822)	(91,385)
Proceeds from calls/maturities of securities held-to-maturity	196,131	133,295
Purchase of securities held-to-maturity	(324,893)	(288,637)
Proceeds from life insurance policies	5,124	375
Net increase in loans	(35,787)	(45,654)
Proceeds from sales of portfolio loans	8,871
Capital expenditures	(2,896)	(1,026)
Net cash used in investing activities	(110,740)	(210,868)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net decrease in time deposits	(70,631)	(45,371)
Net decrease in demand, savings, money market and NOW deposits	(240,173)	(5,463)
Cash dividends	(1,102)	(1,101)
Net increase (decrease) in securities sold under agreements to repurchase	65,270	(18,410)
Net increase in other borrowed funds	249,041	159,052
Net cash provided by financing activities	2,405	88,707
Net decrease in cash and cash equivalents	(91,777)	(102,152)
Cash and cash equivalents at beginning of period	342,503	356,430
Cash and cash equivalents at end of period	250,726	254,278
Cash paid (received) during the period for:
Interest	31,947	19,093
Income taxes	(990)	465
Change in unrealized gains (losses) on securities available-for-sale, net of taxes	(230)	359
Change in unrealized losses on securities transferred to held-to-maturity, net of taxes	419	634
Pension liability adjustment, net of taxes	527	585
Change in due to (from) to broker	$ 800	$ 3,248

Basis of Financial Statement Pr

Basis of Financial Statement Presentation	6 Months Ended
	Jun. 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 independent appraisals and review of other factors, including historical charge-off rates with additional allocations based on 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	6 Months Ended
	Jun. 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 with a corresponding lease liability. 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 April 2019, FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments to improve the Codifications or correct any unintended application. Codification improvements to ASU 2016-13 (Topic 326) will be effective on the same date as requirements in 2016-13. Codification improvements to ASU 2017-12 (Topic 815) will be effective as of the beginning of the first annual period beginning after the issuance date and ASU 2016-01 (Topic 825) will be effective for fiscal years beginning after December 15, 2019. Management believes that this ASU does apply and has not determined the impact, if any, as of June 30, 2019. 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, Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit plans. The amendments in this ASU remove disclosures that no longer are considered cost beneficial, clarify the specific requirements of disclosures, and add disclosure requirements identified as relevant. This ASU is effective for annual reporting periods beginning after December 15, 2020. 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 2018-13, Fair Value Measurement (Topic 820), Disclosure Framework-Changes to the Disclosure Requirements for Fair Value. The amendments in this ASU modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement, based on the concepts in the Concepts Statement, including the consideration of costs and benefits. 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 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. 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 analyzing this ASU, has purchased a software solution and is capturing information needed to implement this update. The Company has started to input information and is in the beginning stages of running the software program and comparing to existing results. The Company also began to identify and address portfolio differences, if any. The Company has not determined the impact, if any, as of June 30, 2019. 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	6 Months Ended
	Jun. 30, 2019
Text Block [Abstract]
Securities Available-for-Sale	Note 3. Securities Available-for-Sale June 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 3,954 20 — 3,974 3,946 — 31 3,915 SBA Backed Securities 64,970 96 54 65,012 70,477 1 284 70,194 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 176,607 187 639 176,155 162,604 536 250 162,890 Privately Issued Residential Mortgage-Backed Securities 622 7 2 627 679 3 10 672 Obligations Issued by States and Political Subdivisions 41,946 56 — 42,002 93,445 58 — 93,503 Other Debt Securities 3,600 65 33 3,632 3,600 37 44 3,593 Total $ 291,699 $ 431 $ 728 $ 291,402 $ 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 $211,916,000 and $197,304,000 at June 30, 2109 and December 31, 2018, respectively. Also included in securities available-for-sale available-for-sale available-for-sale 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 Amortized Fair (in thousands) Within one year $ 39,726 $ 39,725 After one but within five years 123,800 123,830 After five but within ten years 90,050 89,822 More than 10 years 38,123 38,025 Total $ 291,699 $ 291,402 The weighted average remaining life of investment securities available-for-sale As of June 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 change in the unrealized losses on the Obligations Issued by States and Political Subdivisions, Privately Issued Residential Mortgage-Backed Securities and Other Debt Securities was primarily caused by changes in credit spreads and liquidity issues in the marketplace. 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 June 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 June 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 — — 30,790 54 30,790 54 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 66,227 441 28,673 198 94,900 639 Privately Issued Residential Mortgage-Backed Securities — — 296 2 296 2 Obligations Issued by States and Political Subdivisions — — — — — — Other Debt Securities 800 1 467 32 1,267 33 Total temporarily impaired securities $ 67,027 $ 442 $ 60,226 $ 286 $ 127,253 $ 728 The following table shows the temporarily impaired securities of the Company’s available-for-sale 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	6 Months Ended
	Jun. 30, 2019
Text Block [Abstract]
Investment Securities Held-to-Maturity	Note 4. Investment Securities Held-to-Maturity June 30, 2019 December 31, 2018 Amortized Gross Gross Estimated Amortized Gross Gross Estimated (in thousands) U.S. Treasury $ — $ — $ — $ — $ 9,960 $ — $ 2 $ 9,958 U.S. Government Sponsored Enterprises 162,870 770 72 163,568 234,228 336 803 233,761 SBA Backed Securities 48,666 288 224 48,730 52,051 — 2,065 49,986 U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities 1,967,032 20,946 15,751 1,972,227 1,750,408 2,324 55,016 1,697,716 Total $ 2,178,568 $ 22,004 $ 16,047 $ 2,184,525 $ 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 $1,693,719,000 and $1,441,059,000 at June 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 $441,929,000 and $291,190,000 at June 30, 2019 and December 31, 2018, respectively. There were no sales of held-to-maturity At June 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 Amortized Fair (in thousands) Within one year $ 39,249 $ 39,178 After one but within five years 1,831,793 1,836,959 After five but within ten years 294,940 295,580 More than ten years 12,586 12,808 Total $ 2,178,568 $ 2,184,525 The weighted average remaining life of investment securities held-to-maturity As of June 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 June 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 June 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 — — 29,914 72 29,914 72 SBA Backed Securities — — 25,057 224 25,057 224 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 19,919 20 725,439 15,731 745,358 15,751 Total temporarily impaired securities $ 19,919 $ 20 $ 780,410 $ 16,027 $ 800,329 $ 16,047 The following table shows the temporarily impaired securities of the Company’s held-to-maturity 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	6 Months Ended
	Jun. 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 Six months ended 2019 2018 2019 2018 (in thousands) Allowance for loan losses, beginning of period $ 28,848 $ 26,695 $ 28,543 $ 26,255 Loans charged off (75 ) (72 ) (218 ) (159 ) Recoveries on loans previously charged-off 47 71 120 148 Net recoveries (charge-offs) (28 ) (1 ) (98 ) (11 ) Provision charged to expense 250 450 625 900 Allowance for loan losses, end of period $ 29,070 $ 27,144 $ 29,070 $ 27,144 Further information pertaining to the allowance for loan losses for the three months ending June 30, 2019 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at March 31, 2019 $ 1,011 $ 11,156 $ 1,998 $ 10,767 $ 2,135 $ 342 $ 1,101 $ 338 $ 28,848 Charge-offs — (8 ) — — — (67 ) — — (75 ) Recoveries — 7 — — — 40 — — 47 Provision 41 183 (166 ) 81 75 65 19 (48 ) 250 Ending balance at June 30, 2019 $ 1,052 $ 11,338 $ 1,832 $ 10,848 $ 2,210 $ 380 $ 1,120 $ 290 $ 29,070 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 248 $ — $ 85 $ — $ — $ — $ — $ 333 Amount of allowance for loan losses for loans not deemed to be impaired $ 1,052 $ 11,090 $ 1,832 $ 10,763 $ 2,210 $ 380 $ 1,120 $ 290 $ 28,737 Loans: Ending balance $ 13,751 $ 764,492 $ 95,682 $ 758,242 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,312,571 Loans deemed to be impaired $ — $ 548 $ — $ 3,365 $ — $ — $ — $ — $ 3,913 Loans not deemed to be impaired $ 13,751 $ 763,944 $ 95,682 $ 754,877 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,308,658 Further information pertaining to the allowance for loan losses for the six months ending June 30, 2019 follows: 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 — (51 ) — — — (167 ) — — (218 ) Recoveries — 25 — — — 95 — — 120 Provision (40 ) 366 (6 ) 185 20 87 9 4 625 Ending balance at June 30, 2019 $ 1,052 $ 11,338 $ 1,832 $ 10,848 $ 2,210 $ 380 $ 1,120 $ 290 $ 29,070 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 248 $ — $ 85 $ — $ — $ — $ — $ 333 Amount of allowance for loan losses for loans not deemed to be impaired $ 1,052 $ 11,090 $ 1,832 $ 10,763 $ 2,210 $ 380 $ 1,120 $ 290 $ 28,737 Loans: Ending balance $ 13,751 $ 764,492 $ 95,682 $ 758,242 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,312,571 Loans deemed to be impaired $ — $ 548 $ — $ 3,365 $ — $ — $ — $ — $ 3,913 Loans not deemed to be impaired $ 13,751 $ 763,944 $ 95,682 $ 754,877 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,308,658 Further information pertaining to the allowance for loan losses for the three months ending June 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at March 31, 2018 $ 1,438 $ 9,664 $ 1,720 $ 9,787 $ 2,459 $ 321 $ 1,067 $ 239 $ 26,695 Charge-offs — — — — — (72 ) — — (72 ) Recoveries — 10 — — — 61 — — 71 Provision (805 ) 710 (16 ) 422 34 26 11 68 450 Ending balance at June 30, 2018 $ 633 $ 10,384 $ 1,704 $ 10,209 $ 2,493 $ 336 $ 1,078 $ 307 $ 27,144 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 47 $ — $ 91 $ 575 $ — $ — $ — $ 713 Amount of allowance for loan losses for loans not deemed to be impaired $ 633 $ 10,337 $ 1,704 $ 10,118 $ 1,918 $ 336 $ 1,078 $ 307 $ 26,431 Loans: Ending balance $ 7,729 $ 761,467 $ 103,027 $ 735,083 $ 316,248 $ 21,662 $ 276,397 $ — $ 2,221,613 Loans deemed to be impaired $ — $ 592 $ — $ 2,505 $ 2,675 $ — $ — $ — $ 5,772 Loans not deemed to be impaired $ 7,729 $ 760,875 $ 103,027 $ 732,578 $ 313,573 $ 21,662 $ 276,397 $ — $ 2,215,841 Further information pertaining to the allowance for loan losses for the six months ending June 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at December 31, 2107 $ 1,645 $ 9,651 $ 1,720 $ 9,728 $ 1,873 $ 373 $ 989 $ 276 $ 26,255 Charge-offs — (5 ) — — — (154 ) — — (159 ) Recoveries — 33 — — — 115 — — 148 Provision (1,012 ) 705 (16 ) 481 620 2 89 31 900 Ending balance at June 30, 2018 $ 633 $ 10,384 $ 1,704 $ 10,209 $ 2,493 $ 336 $ 1,078 $ 307 $ 27,144 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 47 $ — $ 91 $ 575 $ — $ — $ — $ 713 Amount of allowance for loan losses for loans not deemed to be impaired $ 633 $ 10,337 $ 1,704 $ 10,118 $ 1,918 $ 336 $ 1,078 $ 307 $ 26,431 Loans: Ending balance $ 7,729 $ 761,467 $ 103,027 $ 735,083 $ 316,248 $ 21,662 $ 276,397 $ — $ 2,221,613 Loans deemed to be impaired $ — $ 592 $ — $ 2,505 $ 2,675 $ — $ — $ — $ 5,772 Loans not deemed to be impaired $ 7,729 $ 760,875 $ 103,027 $ 732,578 $ 313,573 $ 21,662 $ 276,397 $ — $ 2,215,841 The Company utilizes a six grade internal loan rating system for commercial real estate, construction and commercial loans as follows: Loans rated 1-3 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 June 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 June 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 June 30, 2019 and December 31, 2018 and are doubtful for full collection. 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 June 30, 2019. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 $ 13,751 $ 759,919 $ 95,682 $ 730,131 4 (Monitor) — 4,025 — 24,746 5 (Substandard) — — — — 6 (Doubtful) — — — — Impaired — 548 — 3,365 Total $ 13,751 $ 764,492 $ 95,682 $ 758,242 The following table presents the Company’s loans by risk rating at December 31, 2018. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 $ 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 June 30, 2019 and are included within the total loan portfolio. Commercial Municipal Commercial Total (in thousands) Credit Rating: Aaa – Aa3 $ 482,138 $ 53,532 $ 41,016 $ 576,686 A1 – A3 188,195 7,480 150,687 346,362 Baa1 – Baa3 — 26,970 120,048 147,018 Ba2 — 5,900 — 5,900 Total $ 670,333 $ 93,882 $ 311,751 $ 1,075,966 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 June 30, 2019 follows: Accruing 30-89 Non Accruing Total Current Total (in thousands) Construction and land development $ — $ — $ — $ — $ 13,751 $ 13,751 Commercial and industrial 173 258 — 431 764,061 764,492 Municipal — — — — 95,682 95,682 Commercial real estate 158 1,140 — 1,298 756,944 758,242 Residential real estate 1,906 518 — 2,424 344,161 346,585 Consumer and overdrafts 7 2 — 9 22,600 22,609 Home equity 1,239 981 — 2,220 308,990 311,210 Total $ 3,483 $ 2,899 $ — $ 6,382 $ 2,306,189 $ 2,312,571 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 charged-off The following is information pertaining to impaired loans for June 30, 2019: Carrying Unpaid Required Average Interest Average Interest (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 78 283 — 83 1 84 2 Municipal — — — — — — — Commercial real estate 1,441 1,585 — 812 5 545 11 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 1,519 $ 1,868 $ — $ 895 $ 6 $ 629 $ 13 With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 470 470 248 349 3 317 6 Municipal — — — — — — — Commercial real estate 1,924 1,924 85 2,213 17 2,409 34 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 2,394 $ 2,394 $ 333 $ 2,562 $ 20 $ 2,726 $ 40 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 548 753 248 432 4 401 8 Municipal — — — — — — — Commercial real estate 3,365 3,509 85 3,025 22 2,954 45 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 3,913 $ 4,262 $ 333 $ 3,457 $ 26 $ 3,355 $ 53 The following is information pertaining to impaired loans for June 30, 2018: Carrying Unpaid Required Average Interest Average Interest (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 162 366 — 170 — 170 — Municipal — — — — — — — Commercial real estate 524 658 — 528 — 534 — Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 686 $ 1,024 $ — $ 698 $ — $ 704 $ — With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 430 430 47 431 7 433 12 Municipal — — — — — — — Commercial real estate 1,981 1,981 91 1,985 40 1,992 63 Residential real estate 2,675 2,675 575 2,675 10 2,675 16 Consumer — — — — — — — Home equity — — — — — — — Total $ 5,086 $ 5,086 $ 713 $ 5,091 $ 57 $ 5,100 $ 91 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 592 796 47 601 7 603 12 Municipal — — — — — — — Commercial real estate 2,505 2,639 91 2,513 40 2,526 63 Residential real estate 2,675 2,675 575 2,675 10 2,675 16 Consumer — — — — — — — Home equity — — — — — — — Total $ 5,772 $ 6,110 $ 713 $ 5,789 $ 57 $ 5,804 $ 91 Troubled debt restructurings are identified as a modification in which a concession was granted to a customer who was having financial difficulties. This concession may be below market rate, longer amortization/term, or a lower payment amount. The present value calculation of the modification did not result in an increase in the allowance for these loans beyond any previously established allocations. There was no troubled debt restructuring that occurred during the six month period ended June 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 six months of 2019. There was one residential real estate loan and one consumer loan that were modified and considered troubled debt restructurings 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 pre-modification

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive Income	6 Months Ended
	Jun. 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 (in thousands) Unrealized gains and losses on available-for-sale $ 7 $ — Net gains on sales of investments Tax (expense) or benefit (2 ) — Provision for income taxes Net of tax $ 5 $ — Net income Accretion of unrealized losses transferred $ (276 ) $ (343 ) Interest on securities held-to-maturity Tax (expense) or benefit 73 90 Provision for income taxes Net of tax $ (203 ) $ (253 ) Net income Amortization of defined benefit pension items Prior-service costs $ (29 )(b) $ (4 )(b) Salaries and employee benefits Actuarial gains (losses) (338 )(b) (402 )(b) Salaries and employee benefits Total before tax (367 ) (406 ) Income before taxes Tax (expense) or benefit 103 114 Provision for income taxes Net of tax $ (264 ) $ (292 ) Net income Details about Accumulated Other Comprehensive Income Components Six Six Affected Line Item in the Statement where Net (in thousands) Unrealized gains and losses on available-for-sale $ 7 $ 197 Net gains on sales of investments Tax (expense) or benefit (2 ) (55 ) Provision for income taxes Net of tax $ 5 $ 142 Net income Accretion of unrealized losses transferred $ (570 ) $ (863 ) Interest on securities held-to-maturity Tax (expense) or benefit 151 229 Provision for income taxes Net of tax $ (419 ) $ (634 ) Net income Amortization of defined benefit pension items Prior-service costs $ (58 )(b) $ (8 )(b) Salaries and employee benefits Actuarial gains (losses) (675 )(b) (805 )(b) Salaries and employee benefits Total before tax (733 ) (813 ) Income before taxes Tax (expense) or benefit 206 228 Provision for income taxes Net of tax $ (527 ) $ (585 ) 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")	6 Months Ended
	Jun. 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 June 30, 2019 and 2018. The following table is a reconciliation of basic EPS and diluted EPS. Three Months Ended Six Months Ended (in thousands except share and per share data) 2019 2018 2019 2018 Basic EPS Computation: Numerator: Net income, Class A $ 7,460 $ 7,076 $ 14,867 $ 13,138 Net income, Class B 2,006 1,922 4,017 3,569 Denominator: Weighted average shares outstanding, Class A 3,620,449 3,608,029 3,615,389 3,608,029 Weighted average shares outstanding, Class B 1,947,460 1,959,880 1,952,520 1,959,880 Basic EPS, Class A $ 2.06 $ 1.96 $ 4.11 $ 3.64 Basic EPS, Class B 1.03 0.98 2.06 1.82 Diluted EPS Computation: Numerator: Net income, Class A $ 7,460 $ 7,076 $ 14,867 $ 13,138 Net income, Class B 2,006 1,922 4,017 3,569 Total net income, for diluted EPS, Class A computation 9,466 8,998 18,884 16,707 Denominator: Weighted average shares outstanding, basic, Class A 3,620,449 3,608,029 3,615,389 3,608,029 Weighted average shares outstanding, Class B 1,947,460 1,959,880 1,952,520 1,959,880 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 1,947,460 1,959,880 1,952,520 1,959,880 Diluted EPS, Class A $ 1.70 $ 1.62 $ 3.39 $ 3.00 Diluted EPS, Class B 1.03 0.98 2.06 1.82

Employee Benefits

Employee Benefits	6 Months Ended
	Jun. 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 June 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 276 $ 353 $ 256 $ 277 Interest 473 370 482 346 Expected return on plan assets (819 ) (954 ) — — Recognized prior service cost (benefit) — (25 ) 28 29 Recognized net actuarial losses 229 227 109 176 Net periodic benefit (credit) cost $ 159 $ (29 ) $ 875 $ 828 Components of Net Periodic Benefit Cost for the Six Months Ended June 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 552 $ 706 $ 512 $ 554 Interest 946 740 964 693 Expected return on plan assets (1,638 ) (1,908 ) — — Recognized prior service cost (benefit) — (50 ) 56 58 Recognized net actuarial losses 458 454 218 352 Net periodic benefit (credit) cost $ 318 $ (58 ) $ 1,750 $ 1,657 Approximately $1,004,000 and $339,000 of costs other than service costs, from the table above, are included in other expenses for the six months ended June 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	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 9. Fair Value Measurements The Company follows FASB ASC 820-10, 2016-1, (Subtopic 825-10) Recognition and Measurement of Financial Assets and Financial Liabilities 820-10 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 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 non-investment The results of the fair value hierarchy as of June 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) U.S. Treasury $ — $ — $ — $ — U.S. Government Sponsored Enterprises 3,974 — 3,974 — SBA Backed Securities 65,012 — 65,012 — U.S. Government Agency and Sponsored Mortgage-Backed Securities 176,155 — 176,155 — Privately Issued Residential Mortgage-Backed Securities 627 — 627 — Obligations Issued by States and Political Subdivisions 42,002 — 4,775 37,227 Other Debt Securities 3,632 — 3,632 — Total $ $ — $ 254,175 $ 37,227 Equity Securities $ 1,681 $ 340 $ 1,341 $ — Financial Instruments Measured at Fair Value on a Non-recurring Other Real Estate Owned $ 2,100 $ — $ — $ 2,100 Impaired Loans $ 1,393 $ — $ — $ 1,393 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 to impaired loans recognized for the three and six month periods ended June 30, 2019 amounted to $244,000 and $242,000, respectively. 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 Valuation Technique Unobservable Input Unobservable Input Securities AFS (4) $ 37,227 Discounted cash flow Discount rate 1.9%-3.4% (3) Other Real Estate Owned $ 2,100 Appraisal of collateral (1) Appraisal adjustments (2) 30% discount Impaired Loans $ 1,393 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 six month period ended June 30, 2019 are shown in the table below: Obligations Total Balance at December 31, 2018 $ 88,728 $ 88,728 Purchases 10,007 10,007 Maturities and calls (61,488 ) (61,488 ) Transfer to Level 2 — — Amortization (20 ) (20 ) Changes in fair value — — Balance at June 30, 2019 $ 37,227 $ 37,227 The amortized cost of Level 3 securities was $37,227,000 at June 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 other real estate owned was reduced by $125,000 for the first six months of 2019. The fair value of impaired loans increased by $1,142,000, for the first six months of 2019, mainly attributable to two loans added to impaired loans. There were no liabilities measured at fair value on a recurring or nonrecurring basis during the six month period ended June 30, 2019. The changes in Level 3 securities for the six month period ended June 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 — 90,701 90,701 Maturities and calls — (42,197 ) (42,197 ) Transfer to Level 2 (4,459 ) (59 ) (4,518 ) Amortization — — — Changes in fair value — — — Balance at June 30, 2018 $ — $ 126,586 $ 126,586 The amortized cost of Level 3 securities was $126,586,000 at June 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 six months ended June 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 six month period ended June 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-Backed Securities 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 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 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	6 Months Ended
	Jun. 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 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 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 June 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 June 30, 2019 Carrying Estimated Fair Value Level 2 Level 3 (in thousands) Financial assets: Securities held-to-maturity $ 2,178,568 $ 2,184,525 $ — $ 2,184,525 $ — Loans (1) 2,283,501 2,371,718 — — 2,371,718 Financial liabilities: Time deposits 489,948 492,970 — 492,970 — Other borrowed funds 451,419 454,905 — 454,905 — 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	6 Months Ended
	Jun. 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 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 six months ended June 30, 2018 and June 30, 2019, respectively, as a result of adopting Topic 606. B. Practical Expedients The Company applies the practical expedient in paragraph 606-10-50-14 The Company applies the practical expedient in paragraph 606-10-32-18 C. Nature of goods and services The vast majority of the Company’s revenue is specifically out-of-scope in-scope, 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. Six Revenue Six Revenue (dollars in thousands) Total net interest income $ 46,688 $ — $ 45,667 $ — Noninterest income: Service charges on deposit accounts 4,491 4,491 4,131 4,131 Lockbox fees 2,081 2,081 1,412 1,412 Net gains on sales of securities 7 — 197 — Gains on sales of mortgage loans 154 — — — Other income 2,691 1,610 2,175 1,464 Total noninterest income 9,424 8,182 7,915 7,007 Total revenues $ 56,112 $ 8,182 $ 53,582 $ 7,007 Three Revenue Three Revenue (dollars in thousands) Total net interest income $ 23,250 $ — $ 23,199 $ — Noninterest income: Service charges on deposit accounts 2,282 2,282 2,064 2,064 Lockbox fees 992 992 621 621 Net gains on sales of securities 7 — — — Gains on sales of mortgage loans 139 — — — Other income 1,577 810 1,037 745 Total noninterest income 4,997 4,084 3,722 3,430 Total revenues $ 28,247 $ 4,084 $ 26,921 $ 3,430 The following table provides information about receivables with customers. June 30, December 31, (dollars in thousands) Receivables, which are included in “Other assets” $ 1,181 $ 1,205

Leases

Leases	6 Months Ended
	Jun. 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 Company also has one sublease for part of a data processing center that the Company currently leases from a lessor. The sublease expires in 2022 with an option to terminate and no option to extend. Lease income, for the sublease, totaled approximately $19,000 for the six months ended June 30, 2019. The components of lease expense were as follows: Three Six (in thousands) Operating lease cost $ 563 $ 1,126 Variable lease cost 136 284 Total lease cost $ 699 $ 1,410 Supplemental cash flow information related to leases was as follows: Three Six (in thousands) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 539 $ 1,077 Right-of-use Operating leases $ 442 $ 885 Supplemental balance sheet information related to leases was as follows: 6/30/2019 (in thousands, except lease term and discount rate) Operating Leases: Operating lease right-of-use $ 14,197 Operating lease liabilities $ 14,356 Weighted Average Remaining Lease Term: Operating Leases 11 Years 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 June 30, December 31, (in thousands) Year Ending December 31, 2019 $ 1,117 $ 2,490 2020 2,168 2,170 2021 1,889 1,694 2022 1,733 1,331 2023 1,671 1,104 Thereafter 8,949 1,074 Total lease payments $ 17,527 $ 9,863 Less imputed interest (3,171 ) Present value of lease liability $ 14,356

Recent Accounting Developments

Recent Accounting Developments (Policies)	6 Months Ended
	Jun. 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 with a corresponding lease liability. 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 April 2019, FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments to improve the Codifications or correct any unintended application. Codification improvements to ASU 2016-13 (Topic 326) will be effective on the same date as requirements in 2016-13. Codification improvements to ASU 2017-12 (Topic 815) will be effective as of the beginning of the first annual period beginning after the issuance date and ASU 2016-01 (Topic 825) will be effective for fiscal years beginning after December 15, 2019. Management believes that this ASU does apply and has not determined the impact, if any, as of June 30, 2019. 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, Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit plans. The amendments in this ASU remove disclosures that no longer are considered cost beneficial, clarify the specific requirements of disclosures, and add disclosure requirements identified as relevant. This ASU is effective for annual reporting periods beginning after December 15, 2020. 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 2018-13, Fair Value Measurement (Topic 820), Disclosure Framework-Changes to the Disclosure Requirements for Fair Value. The amendments in this ASU modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement, based on the concepts in the Concepts Statement, including the consideration of costs and benefits. 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 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. 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 analyzing this ASU, has purchased a software solution and is capturing information needed to implement this update. The Company has started to input information and is in the beginning stages of running the software program and comparing to existing results. The Company also began to identify and address portfolio differences, if any. The Company has not determined the impact, if any, as of June 30, 2019. 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)	6 Months Ended
	Jun. 30, 2019
Text Block [Abstract]
Summary of Securities Available-for-Sale	June 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 3,954 20 — 3,974 3,946 — 31 3,915 SBA Backed Securities 64,970 96 54 65,012 70,477 1 284 70,194 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 176,607 187 639 176,155 162,604 536 250 162,890 Privately Issued Residential Mortgage-Backed Securities 622 7 2 627 679 3 10 672 Obligations Issued by States and Political Subdivisions 41,946 56 — 42,002 93,445 58 — 93,503 Other Debt Securities 3,600 65 33 3,632 3,600 37 44 3,593 Total $ 291,699 $ 431 $ 728 $ 291,402 $ 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 Amortized Fair (in thousands) Within one year $ 39,726 $ 39,725 After one but within five years 123,800 123,830 After five but within ten years 90,050 89,822 More than 10 years 38,123 38,025 Total $ 291,699 $ 291,402
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 June 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 — — 30,790 54 30,790 54 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 66,227 441 28,673 198 94,900 639 Privately Issued Residential Mortgage-Backed Securities — — 296 2 296 2 Obligations Issued by States and Political Subdivisions — — — — — — Other Debt Securities 800 1 467 32 1,267 33 Total temporarily impaired securities $ 67,027 $ 442 $ 60,226 $ 286 $ 127,253 $ 728 The following table shows the temporarily impaired securities of the Company’s available-for-sale 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)	6 Months Ended
	Jun. 30, 2019
Text Block [Abstract]
Summary of Held-to-Maturity Securities	June 30, 2019 December 31, 2018 Amortized Gross Gross Estimated Amortized Gross Gross Estimated (in thousands) U.S. Treasury $ — $ — $ — $ — $ 9,960 $ — $ 2 $ 9,958 U.S. Government Sponsored Enterprises 162,870 770 72 163,568 234,228 336 803 233,761 SBA Backed Securities 48,666 288 224 48,730 52,051 — 2,065 49,986 U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities 1,967,032 20,946 15,751 1,972,227 1,750,408 2,324 55,016 1,697,716 Total $ 2,178,568 $ 22,004 $ 16,047 $ 2,184,525 $ 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 Amortized Fair (in thousands) Within one year $ 39,249 $ 39,178 After one but within five years 1,831,793 1,836,959 After five but within ten years 294,940 295,580 More than ten years 12,586 12,808 Total $ 2,178,568 $ 2,184,525
Unrealized Market Loss of Securities	The following table shows the temporarily impaired securities of the Company’s held-to-maturity June 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 — — 29,914 72 29,914 72 SBA Backed Securities — — 25,057 224 25,057 224 U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities 19,919 20 725,439 15,731 745,358 15,751 Total temporarily impaired securities $ 19,919 $ 20 $ 780,410 $ 16,027 $ 800,329 $ 16,047 The following table shows the temporarily impaired securities of the Company’s held-to-maturity 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)	6 Months Ended
	Jun. 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 Six months ended 2019 2018 2019 2018 (in thousands) Allowance for loan losses, beginning of period $ 28,848 $ 26,695 $ 28,543 $ 26,255 Loans charged off (75 ) (72 ) (218 ) (159 ) Recoveries on loans previously charged-off 47 71 120 148 Net recoveries (charge-offs) (28 ) (1 ) (98 ) (11 ) Provision charged to expense 250 450 625 900 Allowance for loan losses, end of period $ 29,070 $ 27,144 $ 29,070 $ 27,144
Summary of Allowance for Loan Losses	Further information pertaining to the allowance for loan losses for the three months ending June 30, 2019 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at March 31, 2019 $ 1,011 $ 11,156 $ 1,998 $ 10,767 $ 2,135 $ 342 $ 1,101 $ 338 $ 28,848 Charge-offs — (8 ) — — — (67 ) — — (75 ) Recoveries — 7 — — — 40 — — 47 Provision 41 183 (166 ) 81 75 65 19 (48 ) 250 Ending balance at June 30, 2019 $ 1,052 $ 11,338 $ 1,832 $ 10,848 $ 2,210 $ 380 $ 1,120 $ 290 $ 29,070 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 248 $ — $ 85 $ — $ — $ — $ — $ 333 Amount of allowance for loan losses for loans not deemed to be impaired $ 1,052 $ 11,090 $ 1,832 $ 10,763 $ 2,210 $ 380 $ 1,120 $ 290 $ 28,737 Loans: Ending balance $ 13,751 $ 764,492 $ 95,682 $ 758,242 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,312,571 Loans deemed to be impaired $ — $ 548 $ — $ 3,365 $ — $ — $ — $ — $ 3,913 Loans not deemed to be impaired $ 13,751 $ 763,944 $ 95,682 $ 754,877 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,308,658 Further information pertaining to the allowance for loan losses for the six months ending June 30, 2019 follows: 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 — (51 ) — — — (167 ) — — (218 ) Recoveries — 25 — — — 95 — — 120 Provision (40 ) 366 (6 ) 185 20 87 9 4 625 Ending balance at June 30, 2019 $ 1,052 $ 11,338 $ 1,832 $ 10,848 $ 2,210 $ 380 $ 1,120 $ 290 $ 29,070 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 248 $ — $ 85 $ — $ — $ — $ — $ 333 Amount of allowance for loan losses for loans not deemed to be impaired $ 1,052 $ 11,090 $ 1,832 $ 10,763 $ 2,210 $ 380 $ 1,120 $ 290 $ 28,737 Loans: Ending balance $ 13,751 $ 764,492 $ 95,682 $ 758,242 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,312,571 Loans deemed to be impaired $ — $ 548 $ — $ 3,365 $ — $ — $ — $ — $ 3,913 Loans not deemed to be impaired $ 13,751 $ 763,944 $ 95,682 $ 754,877 $ 346,585 $ 22,609 $ 311,210 $ — $ 2,308,658 Further information pertaining to the allowance for loan losses for the three months ending June 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at March 31, 2018 $ 1,438 $ 9,664 $ 1,720 $ 9,787 $ 2,459 $ 321 $ 1,067 $ 239 $ 26,695 Charge-offs — — — — — (72 ) — — (72 ) Recoveries — 10 — — — 61 — — 71 Provision (805 ) 710 (16 ) 422 34 26 11 68 450 Ending balance at June 30, 2018 $ 633 $ 10,384 $ 1,704 $ 10,209 $ 2,493 $ 336 $ 1,078 $ 307 $ 27,144 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 47 $ — $ 91 $ 575 $ — $ — $ — $ 713 Amount of allowance for loan losses for loans not deemed to be impaired $ 633 $ 10,337 $ 1,704 $ 10,118 $ 1,918 $ 336 $ 1,078 $ 307 $ 26,431 Loans: Ending balance $ 7,729 $ 761,467 $ 103,027 $ 735,083 $ 316,248 $ 21,662 $ 276,397 $ — $ 2,221,613 Loans deemed to be impaired $ — $ 592 $ — $ 2,505 $ 2,675 $ — $ — $ — $ 5,772 Loans not deemed to be impaired $ 7,729 $ 760,875 $ 103,027 $ 732,578 $ 313,573 $ 21,662 $ 276,397 $ — $ 2,215,841 Further information pertaining to the allowance for loan losses for the six months ending June 30, 2018 follows: Construction Commercial Municipal Commercial Residential Consumer Home Unallocated Total (in thousands) Allowance for loan losses: Balance at December 31, 2107 $ 1,645 $ 9,651 $ 1,720 $ 9,728 $ 1,873 $ 373 $ 989 $ 276 $ 26,255 Charge-offs — (5 ) — — — (154 ) — — (159 ) Recoveries — 33 — — — 115 — — 148 Provision (1,012 ) 705 (16 ) 481 620 2 89 31 900 Ending balance at June 30, 2018 $ 633 $ 10,384 $ 1,704 $ 10,209 $ 2,493 $ 336 $ 1,078 $ 307 $ 27,144 Amount of allowance for loan losses for loans deemed to be impaired $ — $ 47 $ — $ 91 $ 575 $ — $ — $ — $ 713 Amount of allowance for loan losses for loans not deemed to be impaired $ 633 $ 10,337 $ 1,704 $ 10,118 $ 1,918 $ 336 $ 1,078 $ 307 $ 26,431 Loans: Ending balance $ 7,729 $ 761,467 $ 103,027 $ 735,083 $ 316,248 $ 21,662 $ 276,397 $ — $ 2,221,613 Loans deemed to be impaired $ — $ 592 $ — $ 2,505 $ 2,675 $ — $ — $ — $ 5,772 Loans not deemed to be impaired $ 7,729 $ 760,875 $ 103,027 $ 732,578 $ 313,573 $ 21,662 $ 276,397 $ — $ 2,215,841
Loans by Risk Rating	The following table presents the Company’s loans by risk rating at June 30, 2019. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 $ 13,751 $ 759,919 $ 95,682 $ 730,131 4 (Monitor) — 4,025 — 24,746 5 (Substandard) — — — — 6 (Doubtful) — — — — Impaired — 548 — 3,365 Total $ 13,751 $ 764,492 $ 95,682 $ 758,242 The following table presents the Company’s loans by risk rating at December 31, 2018. Construction Commercial Municipal Commercial (in thousands) Grade: 1-3 $ 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 June 30, 2019 and are included within the total loan portfolio. Commercial Municipal Commercial Total (in thousands) Credit Rating: Aaa – Aa3 $ 482,138 $ 53,532 $ 41,016 $ 576,686 A1 – A3 188,195 7,480 150,687 346,362 Baa1 – Baa3 — 26,970 120,048 147,018 Ba2 — 5,900 — 5,900 Total $ 670,333 $ 93,882 $ 311,751 $ 1,075,966 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 June 30, 2019 follows: Accruing 30-89 Non Accruing Total Current Total (in thousands) Construction and land development $ — $ — $ — $ — $ 13,751 $ 13,751 Commercial and industrial 173 258 — 431 764,061 764,492 Municipal — — — — 95,682 95,682 Commercial real estate 158 1,140 — 1,298 756,944 758,242 Residential real estate 1,906 518 — 2,424 344,161 346,585 Consumer and overdrafts 7 2 — 9 22,600 22,609 Home equity 1,239 981 — 2,220 308,990 311,210 Total $ 3,483 $ 2,899 $ — $ 6,382 $ 2,306,189 $ 2,312,571 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 June 30, 2019: Carrying Unpaid Required Average Interest Average Interest (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 78 283 — 83 1 84 2 Municipal — — — — — — — Commercial real estate 1,441 1,585 — 812 5 545 11 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 1,519 $ 1,868 $ — $ 895 $ 6 $ 629 $ 13 With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 470 470 248 349 3 317 6 Municipal — — — — — — — Commercial real estate 1,924 1,924 85 2,213 17 2,409 34 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 2,394 $ 2,394 $ 333 $ 2,562 $ 20 $ 2,726 $ 40 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 548 753 248 432 4 401 8 Municipal — — — — — — — Commercial real estate 3,365 3,509 85 3,025 22 2,954 45 Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 3,913 $ 4,262 $ 333 $ 3,457 $ 26 $ 3,355 $ 53 The following is information pertaining to impaired loans for June 30, 2018: Carrying Unpaid Required Average Interest Average Interest (in thousands) With no required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 162 366 — 170 — 170 — Municipal — — — — — — — Commercial real estate 524 658 — 528 — 534 — Residential real estate — — — — — — — Consumer — — — — — — — Home equity — — — — — — — Total $ 686 $ 1,024 $ — $ 698 $ — $ 704 $ — With required reserve recorded: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 430 430 47 431 7 433 12 Municipal — — — — — — — Commercial real estate 1,981 1,981 91 1,985 40 1,992 63 Residential real estate 2,675 2,675 575 2,675 10 2,675 16 Consumer — — — — — — — Home equity — — — — — — — Total $ 5,086 $ 5,086 $ 713 $ 5,091 $ 57 $ 5,100 $ 91 Total: Construction and land development $ — $ — $ — $ — $ — $ — $ — Commercial and industrial 592 796 47 601 7 603 12 Municipal — — — — — — — Commercial real estate 2,505 2,639 91 2,513 40 2,526 63 Residential real estate 2,675 2,675 575 2,675 10 2,675 16 Consumer — — — — — — — Home equity — — — — — — — Total $ 5,772 $ 6,110 $ 713 $ 5,789 $ 57 $ 5,804 $ 91

Reclassifications Out of Accu_2

Reclassifications Out of Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 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 (in thousands) Unrealized gains and losses on available-for-sale $ 7 $ — Net gains on sales of investments Tax (expense) or benefit (2 ) — Provision for income taxes Net of tax $ 5 $ — Net income Accretion of unrealized losses transferred $ (276 ) $ (343 ) Interest on securities held-to-maturity Tax (expense) or benefit 73 90 Provision for income taxes Net of tax $ (203 ) $ (253 ) Net income Amortization of defined benefit pension items Prior-service costs $ (29 )(b) $ (4 )(b) Salaries and employee benefits Actuarial gains (losses) (338 )(b) (402 )(b) Salaries and employee benefits Total before tax (367 ) (406 ) Income before taxes Tax (expense) or benefit 103 114 Provision for income taxes Net of tax $ (264 ) $ (292 ) Net income Details about Accumulated Other Comprehensive Income Components Six Six Affected Line Item in the Statement where Net (in thousands) Unrealized gains and losses on available-for-sale $ 7 $ 197 Net gains on sales of investments Tax (expense) or benefit (2 ) (55 ) Provision for income taxes Net of tax $ 5 $ 142 Net income Accretion of unrealized losses transferred $ (570 ) $ (863 ) Interest on securities held-to-maturity Tax (expense) or benefit 151 229 Provision for income taxes Net of tax $ (419 ) $ (634 ) Net income Amortization of defined benefit pension items Prior-service costs $ (58 )(b) $ (8 )(b) Salaries and employee benefits Actuarial gains (losses) (675 )(b) (805 )(b) Salaries and employee benefits Total before tax (733 ) (813 ) Income before taxes Tax (expense) or benefit 206 228 Provision for income taxes Net of tax $ (527 ) $ (585 ) 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)	6 Months Ended
	Jun. 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 Six Months Ended (in thousands except share and per share data) 2019 2018 2019 2018 Basic EPS Computation: Numerator: Net income, Class A $ 7,460 $ 7,076 $ 14,867 $ 13,138 Net income, Class B 2,006 1,922 4,017 3,569 Denominator: Weighted average shares outstanding, Class A 3,620,449 3,608,029 3,615,389 3,608,029 Weighted average shares outstanding, Class B 1,947,460 1,959,880 1,952,520 1,959,880 Basic EPS, Class A $ 2.06 $ 1.96 $ 4.11 $ 3.64 Basic EPS, Class B 1.03 0.98 2.06 1.82 Diluted EPS Computation: Numerator: Net income, Class A $ 7,460 $ 7,076 $ 14,867 $ 13,138 Net income, Class B 2,006 1,922 4,017 3,569 Total net income, for diluted EPS, Class A computation 9,466 8,998 18,884 16,707 Denominator: Weighted average shares outstanding, basic, Class A 3,620,449 3,608,029 3,615,389 3,608,029 Weighted average shares outstanding, Class B 1,947,460 1,959,880 1,952,520 1,959,880 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 1,947,460 1,959,880 1,952,520 1,959,880 Diluted EPS, Class A $ 1.70 $ 1.62 $ 3.39 $ 3.00 Diluted EPS, Class B 1.03 0.98 2.06 1.82

Employee Benefits (Tables)

Employee Benefits (Tables)	6 Months Ended
	Jun. 30, 2019
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost	Components of Net Periodic Benefit Cost for the Three Months Ended June 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 276 $ 353 $ 256 $ 277 Interest 473 370 482 346 Expected return on plan assets (819 ) (954 ) — — Recognized prior service cost (benefit) — (25 ) 28 29 Recognized net actuarial losses 229 227 109 176 Net periodic benefit (credit) cost $ 159 $ (29 ) $ 875 $ 828 Components of Net Periodic Benefit Cost for the Six Months Ended June 30, Pension Benefits Supplemental Insurance/ 2019 2018 2019 2018 (in thousands) Service cost $ 552 $ 706 $ 512 $ 554 Interest 946 740 964 693 Expected return on plan assets (1,638 ) (1,908 ) — — Recognized prior service cost (benefit) — (50 ) 56 58 Recognized net actuarial losses 458 454 218 352 Net periodic benefit (credit) cost $ 318 $ (58 ) $ 1,750 $ 1,657

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 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 June 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) U.S. Treasury $ — $ — $ — $ — U.S. Government Sponsored Enterprises 3,974 — 3,974 — SBA Backed Securities 65,012 — 65,012 — U.S. Government Agency and Sponsored Mortgage-Backed Securities 176,155 — 176,155 — Privately Issued Residential Mortgage-Backed Securities 627 — 627 — Obligations Issued by States and Political Subdivisions 42,002 — 4,775 37,227 Other Debt Securities 3,632 — 3,632 — Total $ $ — $ 254,175 $ 37,227 Equity Securities $ 1,681 $ 340 $ 1,341 $ — Financial Instruments Measured at Fair Value on a Non-recurring Other Real Estate Owned $ 2,100 $ — $ — $ 2,100 Impaired Loans $ 1,393 $ — $ — $ 1,393 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-Backed Securities 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 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 Valuation Technique Unobservable Input Unobservable Input Securities AFS (4) $ 37,227 Discounted cash flow Discount rate 1.9%-3.4% (3) Other Real Estate Owned $ 2,100 Appraisal of collateral (1) Appraisal adjustments (2) 30% discount Impaired Loans $ 1,393 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 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 six month period ended June 30, 2019 are shown in the table below: Obligations Total Balance at December 31, 2018 $ 88,728 $ 88,728 Purchases 10,007 10,007 Maturities and calls (61,488 ) (61,488 ) Transfer to Level 2 — — Amortization (20 ) (20 ) Changes in fair value — — Balance at June 30, 2019 $ 37,227 $ 37,227 Auction Rate Obligations Total (in thousands) Balance at December 31, 2017 $ 4,459 $ 78,141 $ 82,600 Purchases — 90,701 90,701 Maturities and calls — (42,197 ) (42,197 ) Transfer to Level 2 (4,459 ) (59 ) (4,518 ) Amortization — — — Changes in fair value — — — Balance at June 30, 2018 $ — $ 126,586 $ 126,586

Fair Values of Financial Inst_2

Fair Values of Financial Instruments (Tables)	6 Months Ended
	Jun. 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 June 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 June 30, 2019 Carrying Estimated Fair Value Level 2 Level 3 (in thousands) Financial assets: Securities held-to-maturity $ 2,178,568 $ 2,184,525 $ — $ 2,184,525 $ — Loans (1) 2,283,501 2,371,718 — — 2,371,718 Financial liabilities: Time deposits 489,948 492,970 — 492,970 — Other borrowed funds 451,419 454,905 — 454,905 — 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)	6 Months Ended
	Jun. 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. Six Revenue Six Revenue (dollars in thousands) Total net interest income $ 46,688 $ — $ 45,667 $ — Noninterest income: Service charges on deposit accounts 4,491 4,491 4,131 4,131 Lockbox fees 2,081 2,081 1,412 1,412 Net gains on sales of securities 7 — 197 — Gains on sales of mortgage loans 154 — — — Other income 2,691 1,610 2,175 1,464 Total noninterest income 9,424 8,182 7,915 7,007 Total revenues $ 56,112 $ 8,182 $ 53,582 $ 7,007 Three Revenue Three Revenue (dollars in thousands) Total net interest income $ 23,250 $ — $ 23,199 $ — Noninterest income: Service charges on deposit accounts 2,282 2,282 2,064 2,064 Lockbox fees 992 992 621 621 Net gains on sales of securities 7 — — — Gains on sales of mortgage loans 139 — — — Other income 1,577 810 1,037 745 Total noninterest income 4,997 4,084 3,722 3,430 Total revenues $ 28,247 $ 4,084 $ 26,921 $ 3,430
Information about Receivables with Customers	The following table provides information about receivables with customers. June 30, December 31, (dollars in thousands) Receivables, which are included in “Other assets” $ 1,181 $ 1,205

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Components of lease expense	The components of lease expense were as follows: Three Six (in thousands) Operating lease cost $ 563 $ 1,126 Variable lease cost 136 284 Total lease cost $ 699 $ 1,410
Supplemental cash flow information related to leases	Supplemental cash flow information related to leases was as follows: Three Six (in thousands) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 539 $ 1,077 Right-of-use Operating leases $ 442 $ 885
Supplemental balance sheet information related to leases	Supplemental balance sheet information related to leases was as follows: 6/30/2019 (in thousands, except lease term and discount rate) Operating Leases: Operating lease right-of-use $ 14,197 Operating lease liabilities $ 14,356 Weighted Average Remaining Lease Term: Operating Leases 11 Years 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 June 30, December 31, (in thousands) Year Ending December 31, 2019 $ 1,117 $ 2,490 2020 2,168 2,170 2021 1,889 1,694 2022 1,733 1,331 2023 1,671 1,104 Thereafter 8,949 1,074 Total lease payments $ 17,527 $ 9,863 Less imputed interest (3,171 ) Present value of lease liability $ 14,356

Basis of Financial Statement _2

Basis of Financial Statement Presentation - Additional Information (Detail)	6 Months Ended
	Jun. 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	Jun. 30, 2019USD ($)
Operating Lease, Right-of-Use Asset	$ 14,197
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	Jun. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 291,699	$ 336,751
Gross Unrealized Gains	431	635
Gross Unrealized Losses	728	627
Total, Fair Value	291,402	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	3,954	3,946
Gross Unrealized Gains	20
Gross Unrealized Losses		31
Total, Fair Value	3,974	3,915
SBA Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	64,970	70,477
Gross Unrealized Gains	96	1
Gross Unrealized Losses	54	284
Total, Fair Value	65,012	70,194
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	176,607	162,604
Gross Unrealized Gains	187	536
Gross Unrealized Losses	639	250
Total, Fair Value	176,155	162,890
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	622	679
Gross Unrealized Gains	7	3
Gross Unrealized Losses	2	10
Total, Fair Value	627	672
Obligations Issued by States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	41,946	93,445
Gross Unrealized Gains	56	58
Total, Fair Value	42,002	93,503
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,600	3,600
Gross Unrealized Gains	65	37
Gross Unrealized Losses	33	44
Total, Fair Value	$ 3,632	$ 3,593

Securities Available-for-Sale_2

Securities Available-for-Sale - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)Security	Jun. 30, 2019USD ($)Security	Jun. 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	$ 1,693,719,000	$ 1,693,719,000		$ 1,441,059,000
Securities available-for-sale are securities at fair value pledged for borrowing	33,224,000	33,224,000		34,787,000
Gross gains on sales of securities	7,000	7,000	$ 197,000
Proceeds from sales of securities available-for-sale		12,330,000	$ 17,871,000
Securities at floating rate or adjustable rate	247,572,000	247,572,000
Security available for sale, amortized cost	$ 291,699,000	291,699,000		$ 336,751,000
Federal Home Loan Bank [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross gains on sales of securities		$ 7,000
Securities AFS [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted average remaining life of investment securities available-for-sale		5 years 3 months 18 days
Number of securities, temporarily impaired for less than 12 months | Security	20	20		10
Number of securities, temporarily impaired for 12 months or longer | Security	21	21		30
Number of securities, temporarily impaired, total | Security	160	160		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	$ 211,916,000	$ 211,916,000		$ 197,304,000
Security available for sale, amortized cost	176,607,000	176,607,000		162,604,000
U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Security available for sale, amortized cost	$ 3,954,000	$ 3,954,000		$ 3,946,000

Securities Available-for-Sale_3

Securities Available-for-Sale - Estimated Maturity Distribution of Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Within one year, Amortized Cost	$ 39,726
After one but within five years, Amortized Cost	123,800
After five but within ten years, Amortized Cost	90,050
More than ten years, Amortized Cost	38,123
Amortized Cost	291,699	$ 336,751
Within one year, Fair Value	39,725
After one but within five years, Fair Value	123,830
After five but within ten years, Fair Value	89,822
More than ten years, Fair Value	38,025
Total, Fair Value	$ 291,402	$ 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	Jun. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 67,027	$ 41,108
Less Than 12 Months, Unrealized Losses	442	80
12 Months or Longer, Fair Value	60,226	93,047
12 Months or Longer, Unrealized Losses	286	547
Total, Fair Value	127,253	134,155
Total, Unrealized Losses	728	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		17,950
Less Than 12 Months, Unrealized Losses		28
12 Months or Longer, Fair Value	30,790	44,323
12 Months or Longer, Unrealized Losses	54	256
Total, Fair Value	30,790	62,273
Total, Unrealized Losses	54	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	66,227	19,244
Less Than 12 Months, Unrealized Losses	441	21
12 Months or Longer, Fair Value	28,673	45,782
12 Months or Longer, Unrealized Losses	198	229
Total, Fair Value	94,900	65,026
Total, Unrealized Losses	639	250
Privately Issued Residential Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	296	495
12 Months or Longer, Unrealized Losses	2	10
Total, Fair Value	296	495
Total, Unrealized Losses	2	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	467	455
12 Months or Longer, Unrealized Losses	32	44
Total, Fair Value	1,267	455
Total, Unrealized Losses	$ 33	$ 44

Investment Securities Held-to_3

Investment Securities Held-to-Maturity - Summary of Held-to-Maturity Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 2,178,568	$ 2,046,647
Gross Unrealized Gains	22,004	2,660
Gross Unrealized Losses	16,047	57,886
Estimated Fair Value	2,184,525	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	162,870	234,228
Gross Unrealized Gains	770	336
Gross Unrealized Losses	72	803
Estimated Fair Value	163,568	233,761
SBA Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	48,666	52,051
Gross Unrealized Gains	288
Gross Unrealized Losses	224	2,065
Estimated Fair Value	48,730	49,986
Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1,967,032	1,750,408
Gross Unrealized Gains	20,946	2,324
Gross Unrealized Losses	15,751	55,016
Estimated Fair Value	$ 1,972,227	$ 1,697,716

Investment Securities Held-to_4

Investment Securities Held-to-Maturity - Additional Information (Detail)	6 Months Ended
	Jun. 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	$ 1,693,719,000	$ 1,441,059,000
Securities held to maturity at floating rate or adjustable rate	$ 115,000
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	4	56
Number of securities, temporarily impaired for 12 months or longer | Security	169	315
Number of securities, temporarily impaired, total | Security	502	475
Held-to-Maturity Securities [Member] | U.S. Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Weighted average remaining life	$ 87,619,000
Federal Home Loan Bank [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities pledged for borrowing at the Federal Home Loan Bank	$ 441,929,000	$ 291,190,000

Investment Securities Held-to_5

Investment Securities Held-to-Maturity - Company's Securities Held-to-Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Within one year, Amortized Cost	$ 39,249
After one but within five years, Amortized Cost	1,831,793
After five but within ten years, Amortized Cost	294,940
More than ten years, Amortized Cost	12,586
Amortized Cost	2,178,568	$ 2,046,647
Within one year, Fair Value	39,178
After one but within five years, Fair Value	1,836,959
After five but within ten years, Fair Value	295,580
More than ten years, Fair Value	12,808
Estimated Fair Value	$ 2,184,525	$ 1,991,421

Investment Securities Held-to_6

Investment Securities Held-to-Maturity - Unrealized Market Loss of Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Less Than 12 Months, Fair Value	$ 19,919	$ 207,932
Less Than 12 Months, Unrealized Losses	20	2,076
12 Months or Longer, Fair Value	780,410	1,369,175
12 Months or Longer, Unrealized Losses	16,027	55,810
Total, Fair Value	800,329	1,577,107
Total, Unrealized Losses	16,047	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		9,849
Less Than 12 Months, Unrealized Losses		42
12 Months or Longer, Fair Value	29,914	69,499
12 Months or Longer, Unrealized Losses	72	761
Total, Fair Value	29,914	79,348
Total, Unrealized Losses	72	803
SBA Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
12 Months or Longer, Fair Value	25,057	49,987
12 Months or Longer, Unrealized Losses	224	2,065
Total, Fair Value	25,057	49,987
Total, Unrealized Losses	224	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	19,919	188,125
Less Than 12 Months, Unrealized Losses	20	2,032
12 Months or Longer, Fair Value	725,439	1,249,689
12 Months or Longer, Unrealized Losses	15,731	52,984
Total, Fair Value	745,358	1,437,814
Total, Unrealized Losses	$ 15,751	$ 55,016

Allowance for Loan Losses - Ana

Allowance for Loan Losses - Analysis of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Receivables [Abstract]
Allowance for loan losses, beginning of year	$ 28,848	$ 26,695	$ 28,543	$ 26,255
Loans charged-off	(75)	(72)	(218)	(159)
Recoveries on loans previously charged-off	47	71	120	148
Net recoveries (charge-offs)	(28)	(1)	(98)	(11)
Provision charged to expense	250	450	625	900
Allowance for loan losses, end of year	$ 29,070	$ 27,144	$ 29,070	$ 27,144

Allowance for Loan Losses - Sum

Allowance for Loan Losses - Summary of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	$ 28,848	$ 26,695	$ 28,543	$ 26,255
Charge-offs	(75)	(72)	(218)	(159)
Recoveries	47	71	120	148
Provision	250	450	625	900
Allowance for loan losses, end of year	29,070	27,144	29,070	27,144
Amount of allowance for loan losses for loans deemed to be impaired	333	713	333	713
Amount of allowance for loan losses for loans not deemed to be impaired	28,737	26,431	28,737	26,431
Loans:
Total loans, net	2,312,571	2,221,613	2,312,571	2,221,613	$ 2,285,578
Loans deemed to be impaired	3,913	5,772	3,913	5,772
Loans not deemed to be impaired	2,308,658	2,215,841	2,308,658	2,215,841
Construction and Land Development [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	1,011	1,438	1,092	1,645
Provision	41	(805)	(40)	(1,012)
Allowance for loan losses, end of year	1,052	633	1,052	633
Amount of allowance for loan losses for loans not deemed to be impaired	1,052	633	1,052	633
Loans:
Total loans, net	13,751	7,729	13,751	7,729	13,628
Loans not deemed to be impaired	13,751	7,729	13,751	7,729
Commercial and Industrial [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	11,156	9,664	10,998	9,651
Charge-offs	(8)		(51)	(5)
Recoveries	7	10	25	33
Provision	183	710	366	705
Allowance for loan losses, end of year	11,338	10,384	11,338	10,384
Amount of allowance for loan losses for loans deemed to be impaired	248	47	248	47
Amount of allowance for loan losses for loans not deemed to be impaired	11,090	10,337	11,090	10,337
Loans:
Total loans, net	764,492	761,467	764,492	761,467	761,625
Loans deemed to be impaired	548	592	548	592
Loans not deemed to be impaired	763,944	760,875	763,944	760,875
Municipal [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	1,998	1,720	1,838	1,720
Provision	(166)	(16)	(6)	(16)
Allowance for loan losses, end of year	1,832	1,704	1,832	1,704
Amount of allowance for loan losses for loans not deemed to be impaired	1,832	1,704	1,832	1,704
Loans:
Total loans, net	95,682	103,027	95,682	103,027	97,290
Loans not deemed to be impaired	95,682	103,027	95,682	103,027
Commercial Real Estate [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	10,767	9,787	10,663	9,728
Provision	81	422	185	481
Allowance for loan losses, end of year	10,848	10,209	10,848	10,209
Amount of allowance for loan losses for loans deemed to be impaired	85	91	85	91
Amount of allowance for loan losses for loans not deemed to be impaired	10,763	10,118	10,763	10,118
Loans:
Total loans, net	758,242	735,083	758,242	735,083	750,362
Loans deemed to be impaired	3,365	2,505	3,365	2,505
Loans not deemed to be impaired	754,877	732,578	754,877	732,578
Residential Real Estate [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	2,135	2,459	2,190	1,873
Provision	75	34	20	620
Allowance for loan losses, end of year	2,210	2,493	2,210	2,493
Amount of allowance for loan losses for loans deemed to be impaired	575	575	575	575
Amount of allowance for loan losses for loans not deemed to be impaired	2,210	1,918	2,210	1,918
Loans:
Total loans, net	346,585	316,248	346,585	316,248	348,250
Loans deemed to be impaired		2,675		2,675
Loans not deemed to be impaired	346,585	313,573	346,585	313,573
Consumer [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	342	321	365	373
Charge-offs	(67)	(72)	(167)	(154)
Recoveries	40	61	95	115
Provision	65	26	87	2
Allowance for loan losses, end of year	380	336	380	336
Amount of allowance for loan losses for loans not deemed to be impaired	380	336	380	336
Loans:
Total loans, net	22,609	21,662	22,609	21,662	22,083
Loans not deemed to be impaired	22,609	21,662	22,609	21,662
Home Equity [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	1,101	1,067	1,111	989
Provision	19	11	9	89
Allowance for loan losses, end of year	1,120	1,078	1,120	1,078
Amount of allowance for loan losses for loans not deemed to be impaired	1,120	1,078	1,120	1,078
Loans:
Total loans, net	311,210	276,397	311,210	276,397	$ 292,340
Loans not deemed to be impaired	311,210	276,397	311,210	276,397
Unallocated [Member]
Allowance for Loan Losses:
Allowance for loan losses, beginning of year	338	239	286	276
Provision	(48)	68	4	31
Allowance for loan losses, end of year	290	307	290	307
Amount of allowance for loan losses for loans not deemed to be impaired	$ 290	$ 307	$ 290	$ 307

Allowance for Loan Losses - Loa

Allowance for Loan Losses - Loans by Risk Rating (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Loans by risk rating
Financing Receivable, Net	$ 2,312,571	$ 2,285,578	$ 2,221,613
Construction and Land Development [Member]
Loans by risk rating
Financing Receivable, Net	13,751	13,628	7,729
Commercial and Industrial [Member]
Loans by risk rating
Financing Receivable, Net	764,492	761,625	761,467
Municipal [Member]
Loans by risk rating
Financing Receivable, Net	95,682	97,290	103,027
Commercial Real Estate [Member]
Loans by risk rating
Financing Receivable, Net	758,242	750,362	$ 735,083
1-3 (Pass) [Member] | Construction and Land Development [Member]
Loans by risk rating
Financing Receivable, Net	13,751	13,628
1-3 (Pass) [Member] | Commercial and Industrial [Member]
Loans by risk rating
Financing Receivable, Net	759,919	757,089
1-3 (Pass) [Member] | Municipal [Member]
Loans by risk rating
Financing Receivable, Net	95,682	97,290
1-3 (Pass) [Member] | Commercial Real Estate [Member]
Loans by risk rating
Financing Receivable, Net	730,131	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	24,746	24,542
Impaired [Member] | Commercial and Industrial [Member]
Loans by risk rating
Financing Receivable, Net	548	401
Impaired [Member] | Commercial Real Estate [Member]
Loans by risk rating
Financing Receivable, Net	$ 3,365	$ 2,650

Allowance for Loan Losses - L_2

Allowance for Loan Losses - Loans by Credit Rating (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	$ 1,075,966	$ 1,071,577
Aaa - Aa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	576,686	588,142
A1 - A3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	346,362	331,458
Baa1 - Baa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	147,018	145,167
Ba2 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	5,900	6,810
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	670,333	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	482,138	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	188,195	172,472
Municipal [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	93,882	95,490
Municipal [Member] | Aaa - Aa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	53,532	54,105
Municipal [Member] | A1 - A3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	7,480	7,605
Municipal [Member] | Baa1 - Baa3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	26,970	26,970
Municipal [Member] | Ba2 [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	5,900	6,810
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable net of deferred income credit quality	311,751	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	41,016	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	150,687	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	$ 120,048	$ 118,197

Allowance for Loan Losses - Agi

Allowance for Loan Losses - Aging of Past Due Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	$ 3,483	$ 4,647
Non Accrual	2,899	1,313
Total Past Due	6,382	5,960
Current Loans	2,306,189	2,279,618
Total loans, net	2,312,571	2,285,578	$ 2,221,613
Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current Loans	13,751	13,628
Total loans, net	13,751	13,628	7,729
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	173	187
Non Accrual	258	115
Total Past Due	431	302
Current Loans	764,061	761,323
Total loans, net	764,492	761,625	761,467
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Current Loans	95,682	97,290
Total loans, net	95,682	97,290	103,027
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	158	774
Non Accrual	1,140	190
Total Past Due	1,298	964
Current Loans	756,944	749,398
Total loans, net	758,242	750,362	735,083
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	1,906	2,554
Non Accrual	518	569
Total Past Due	2,424	3,123
Current Loans	344,161	345,127
Total loans, net	346,585	348,250	316,248
Consumer and overdrafts [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	7	24
Non Accrual	2	14
Total Past Due	9	38
Current Loans	22,600	22,045
Total loans, net	22,609	22,083	21,662
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Accruing 30-89 Days Past Due	1,239	1,108
Non Accrual	981	425
Total Past Due	2,220	1,533
Current Loans	308,990	290,807
Total loans, net	$ 311,210	$ 292,340	$ 276,397

Allowance for Loan Losses - Inf

Allowance for Loan Losses - Information Pertaining to Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	$ 1,519	$ 686	$ 1,519	$ 686
With no required reserve recorded, Unpaid Balance Principal	1,868	1,024	1,868	1,024
With no required reserve recorded, Average Carrying Value Recognized	895	698	629	704
With no required reserve recorded, Interest Income	6		13
With required reserve recorded, Carrying Value	2,394	5,086	2,394	5,086
With required reserve recorded, Unpaid Balance Principal	2,394	5,086	2,394	5,086
With required reserve recorded, Required Reserve	333	713	333	713
With required reserve recorded, Average Carrying Value Recognized	2,562	5,091	2,726	5,100
With required reserve recorded, Interest Income	20	57	40	91
Carrying Value	3,913	5,772	3,913	5,772
Unpaid Balance Principal	4,262	6,110	4,262	6,110
With required reserve recorded, Required Reserve	333	713	333	713
Average Carrying Value Recognized	3,457	5,789	3,355	5,804
Interest Income	26	57	53	91
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	78	162	78	162
With no required reserve recorded, Unpaid Balance Principal	283	366	283	366
With no required reserve recorded, Average Carrying Value Recognized	83	170	84	170
With no required reserve recorded, Interest Income	1		2
With required reserve recorded, Carrying Value	470	430	470	430
With required reserve recorded, Unpaid Balance Principal	470	430	470	430
With required reserve recorded, Required Reserve	248	47	248	47
With required reserve recorded, Average Carrying Value Recognized	349	431	317	433
With required reserve recorded, Interest Income	3	7	6	12
Carrying Value	548	592	548	592
Unpaid Balance Principal	753	796	753	796
With required reserve recorded, Required Reserve	248	47	248	47
Average Carrying Value Recognized	432	601	401	603
Interest Income	4	7	8	12
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	1,441	524	1,441	524
With no required reserve recorded, Unpaid Balance Principal	1,585	658	1,585	658
With no required reserve recorded, Average Carrying Value Recognized	812	528	545	534
With no required reserve recorded, Interest Income	5		11
With required reserve recorded, Carrying Value	1,924	1,981	1,924	1,981
With required reserve recorded, Unpaid Balance Principal	1,924	1,981	1,924	1,981
With required reserve recorded, Required Reserve	85	91	85	91
With required reserve recorded, Average Carrying Value Recognized	2,213	1,985	2,409	1,992
With required reserve recorded, Interest Income	17	40	34	63
Carrying Value	3,365	2,505	3,365	2,505
Unpaid Balance Principal	3,509	2,639	3,509	2,639
With required reserve recorded, Required Reserve	85	91	85	91
Average Carrying Value Recognized	3,025	2,513	2,954	2,526
Interest Income	22	40	45	63
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	575	575	575	575
With required reserve recorded, Average Carrying Value Recognized		2,675		2,675
With required reserve recorded, Interest Income		10		16
Carrying Value		2,675		2,675
Unpaid Balance Principal		2,675		2,675
With required reserve recorded, Required Reserve	$ 575	575	$ 575	575
Average Carrying Value Recognized		2,675		2,675
Interest Income		$ 10		$ 16

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)ContractsContract
Financing Receivable, Allowance for Credit Losses [Line Items]
Specific reserves	$ 713,000	$ 333,000
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	$ 575,000	$ 575,000
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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net gains on sales of securities	$ 7		$ 7	$ 197
Provision for income taxes	(267)	$ (314)	(149)	(815)
Net income	9,466	8,998	18,884	16,707
Salaries and employee benefits	(10,916)	(10,536)	(21,951)	(21,761)
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	7		7	197
Provision for income taxes	(2)		(2)	(55)
Net income	5		5	142
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	(276)	(343)	(570)	(863)
Provision for income taxes	73	90	151	229
Net income	(203)	(253)	(419)	(634)
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)	(58)	(8)
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	(338)	(402)	(675)	(805)
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	(367)	(406)	(733)	(813)
Provision for income taxes	103	114	206	228
Net income	$ (264)	$ (292)	$ (527)	$ (585)

Earnings per Share ("EPS") - Ad

Earnings per Share ("EPS") - Additional Information (Detail)	6 Months Ended
	Jun. 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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 9,466	$ 8,998	$ 18,884	$ 16,707
Class A Common Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 7,460	$ 7,076	$ 14,867	$ 13,138
Weighted average shares outstanding, basic	3,620,449	3,608,029	3,615,389	3,608,029
Basic earnings per share	$ 2.06	$ 1.96	$ 4.11	$ 3.64
Net income	$ 7,460	$ 7,076	$ 14,867	$ 13,138
Weighted average shares outstanding, diluted	5,567,909	5,567,909	5,567,909	5,567,909
Diluted earnings per share	$ 1.70	$ 1.62	$ 3.39	$ 3
Class B Common Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 2,006	$ 1,922	$ 4,017	$ 3,569
Weighted average shares outstanding, basic	1,947,460	1,959,880	1,952,520	1,959,880
Basic earnings per share	$ 1.03	$ 0.98	$ 2.06	$ 1.82
Net income	$ 2,006	$ 1,922	$ 4,017	$ 3,569
Weighted average shares outstanding, diluted	1,947,460	1,959,880	1,952,520	1,959,880
Diluted earnings per share	$ 1.03	$ 0.98	$ 2.06	$ 1.82

Employee Benefits - Additional

Employee Benefits - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 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	$ 1,004,000	$ 339,000

Employee Benefits - Components

Employee Benefits - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Pension Plan [Member]
Components of net periodic benefit cost
Service cost	$ 276	$ 353	$ 552	$ 706
Interest cost	473	370	946	740
Expected return on plan assets	(819)	(954)	(1,638)	(1,908)
Recognized prior service cost		(25)		(50)
Recognized net losses	229	227	458	454
Net periodic cost (benefit)	159	(29)	318	(58)
Supplemental Insurance/ Retirement Plan [Member]
Components of net periodic benefit cost
Service cost	256	277	512	554
Interest cost	482	346	964	693
Recognized prior service cost	28	29	56	58
Recognized net losses	109	176	218	352
Net periodic cost (benefit)	$ 875	$ 828	$ 1,750	$ 1,657

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Specific adjustments to impaired loans recognized	$ 244,000	$ 242,000	$ 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
Real Estate, Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of loans		125,000
Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of loans		1,142,000
Fair Value Measurements, Level 3 Inputs [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Amortized cost of Level 3 securities	37,227,000	37,227,000		$ 126,586,000
Unrealized loss	$ 0	$ 0

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value (Detail) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Securities AFS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Fair Value		$ 37,227	$ 88,728	[1]
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		$ 1,393	$ 251
Valuation Technique		Appraisal of collateral	Appraisal of collateral
Unobservable Input		Appraisal adjustments	Appraisal adjustments
Other Real Estate Owned [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Fair Value		$ 2,100	$ 2,225
Valuation Technique		Appraisal of collateral	Appraisal of collateral
Unobservable Input		Appraisal adjustments	Appraisal adjustments
Unobservable Input Value or Range		30.00%	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		1.9	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		3.4	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	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 88,728	$ 82,600
Purchases	10,007	90,701
Maturities/redemptions	(61,488)	(42,197)
Transfer to Level 2		(4,518)
Amortization	(20)	0
Ending Balance	37,227	126,586
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	10,007	90,701
Maturities/redemptions	(61,488)	(42,197)
Transfer to Level 2		(59)
Amortization	(20)	0
Ending Balance	$ 37,227	$ 126,586

Fair Value Measurements - Finan

Fair Value Measurements - Financial Instruments Measured at Fair Value on a Recurring and Non-recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	$ 291,402	$ 336,759
Fair Value Measurements, Level 2 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	254,175	248,031
Fair Value Measurements, Level 3 Inputs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	37,227	88,728
Other Real Estate Owned	2,100	2,225
Financial Instruments Measured at Fair Value on a Non-recurring Basis Impaired Loans	1,393	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	3,974	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	3,974	3,915
SBA Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	65,012	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	65,012	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	176,155	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	176,155	162,890
Privately Issued Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	627	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	627	672
Obligations Issued by States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	42,002	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	37,227	88,728
Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	3,632	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	3,632	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	340	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	1,341	1,303
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	291,402	336,759
Other Real Estate Owned	2,100	2,225
Financial Instruments Measured at Fair Value on a Non-recurring Basis Impaired Loans	1,393	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	3,974	3,915
Carrying Value [Member] | SBA Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	65,012	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	176,155	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	627	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	42,002	93,503
Carrying Value [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities AFS	3,632	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	$ 1,681	$ 1,596

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	Jun. 30, 2019	Dec. 31, 2018
Financial assets:
Securities held-to-maturity	$ 2,178,568	$ 2,046,647
Loans	2,283,501	2,257,035
Financial liabilities:
Time deposits	489,948	560,579
Other borrowed funds	451,419	202,378
Subordinated debentures	36,083	36,083
Carrying Value [Member]
Financial assets:
Securities held-to-maturity	2,178,568	2,046,647
Loans	2,283,501	2,257,035
Financial liabilities:
Time deposits	489,948	560,579
Other borrowed funds	451,419	202,378
Subordinated debentures	36,083	36,083
Estimated Fair Value [Member]
Financial assets:
Securities held-to-maturity	2,184,525	1,991,421
Loans	2,371,718	2,279,712
Financial liabilities:
Time deposits	492,970	559,988
Other borrowed funds	454,905	203,122
Subordinated debentures	36,083	36,083
Fair Value Measurements, Level 2 Inputs [Member]
Financial assets:
Securities held-to-maturity	2,184,525	1,991,421
Financial liabilities:
Time deposits	492,970	559,988
Other borrowed funds	454,905	203,122
Subordinated debentures	36,083	36,083
Fair Value Measurements, Level 3 Inputs [Member]
Financial assets:
Loans	$ 2,371,718	$ 2,279,712

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Schedule of Revenue from Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total net interest income	$ 23,250	$ 23,199	$ 46,688	$ 45,667
Noninterest income:
Service charges on deposit accounts	2,282	2,064	4,491	4,131
Lockbox fees	992	621	2,081	1,412
Net gains on sales of securities	7		7	197
Gains on sales of mortgage loans	139		154
Other income	1,577	1,037	2,691	2,175
Total noninterest income	4,997	3,722	9,424	7,915
ASU 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Total net interest income	23,250	23,199	46,688	45,667
Noninterest income:
Service charges on deposit accounts	2,282	2,064	4,491	4,131
Lockbox fees	992	621	2,081	1,412
Net gains on sales of securities	7		7	197
Gains on sales of mortgage loans	139		154
Other income	1,577	1,037	2,691	2,175
Total noninterest income	4,997	3,722	9,424	7,915
Total revenues	28,247	26,921	56,112	53,582
ASU 2014-09 [Member] | Revenue Guidance Contracts in Scope of Topic 606 [Member]
Noninterest income:
Service charges on deposit accounts	2,282	2,064	4,491	4,131
Lockbox fees	992	621	2,081	1,412
Other income	810	745	1,610	1,464
Total noninterest income	4,084	3,430	8,182	7,007
Total revenues	$ 4,084	$ 3,430	$ 8,182	$ 7,007

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Information about Receivables with Customers (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Other Assets [Member]
Disaggregation of Revenue [Line Items]
Receivables, which are included in "Other assets"	$ 1,181	$ 1,205

Leases - Additional Information

Leases - Additional Information (Detail)	6 Months Ended
	Jun. 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	$ 19,000
Sublease option to terminate	The 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	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Operating lease cost	$ 563	$ 1,126
Variable lease cost	136	284
Total lease cost	$ 699	$ 1,410

Leases - Supplemental cash flow

Leases - Supplemental cash flow information related to leases (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 539	$ 1,077
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 442	$ 885

Leases - Supplemental balance s

Leases - Supplemental balance sheet information related to leases (Detail) $ in Thousands	Jun. 30, 2019USD ($)
Operating Leases:
Operating lease right-of-use assets, included in other assets	$ 14,197
Operating lease liabilities, included in other liabilities	$ 14,356
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	Jun. 30, 2019	Dec. 31, 2018
Year Ending December 31, 2019	$ 1,117	$ 2,490
2020	2,168	2,170
2021	1,889	1,694
2022	1,733	1,331
2023	1,671	1,104
Thereafter	8,949	1,074
Total lease payments	17,527	$ 9,863
Less imputed interest	(3,171)
Present value of lease liability	$ 14,356