Community Bank System (CBU) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 31, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	COMMUNITY BANK SYSTEM, INC.
Entity Central Index Key	723,188
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 2,967,005,765
Entity Common Stock, Shares Outstanding		51,318,005
Entity Small Business	false
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Ex Transition Period	false
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY

CONSOLIDATED STATEMENTS OF COND

CONSOLIDATED STATEMENTS OF CONDITION - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash and cash equivalents	$ 211,834	$ 221,038
Available-for-sale investment securities (cost of $2,952,278 and $3,007,148, respectively)	2,936,049	3,031,088
Equity and other securities (cost of $44,678 and $50,291, respectively)	45,609	50,291
Loans held for sale, at fair value	83	461
Loans	6,281,121	6,256,757
Allowance for loan losses	(49,284)	(47,583)
Net loans	6,231,837	6,209,174
Goodwill, net	733,503	734,430
Core deposit intangibles, net	18,596	25,025
Other intangibles, net	55,250	65,633
Intangible assets, net	807,349	825,088
Premises and equipment, net	119,988	123,393
Accrued interest and fees receivable	31,048	36,177
Other assets	223,498	249,488
Total assets	10,607,295	10,746,198
Liabilities:
Noninterest-bearing deposits	2,312,816	2,293,057
Interest-bearing deposits	6,009,555	6,151,363
Total deposits	8,322,371	8,444,420
Short-term borrowings	54,400	24,000
Securities sold under agreement to repurchase, short-term	259,367	337,011
Other long-term debt	1,976	2,071
Subordinated debt held by unconsolidated subsidiary trusts	97,939	122,814
Accrued interest and other liabilities	157,459	180,567
Total liabilities	8,893,512	9,110,883
Commitments and contingencies (See Note N)
Shareholders' equity:
Preferred stock, $1.00 par value, 500,000 shares authorized, 0 shares issued	0	0
Common stock, $1.00 par value, 75,000,000 shares authorized; 51,576,839 and 51,263,841 shares issued, respectively	51,577	51,264
Additional paid-in capital	911,748	894,879
Retained earnings	795,563	700,557
Accumulated other comprehensive (loss)	(45,305)	(3,699)
Treasury stock, at cost (319,015 shares including 207,403 shares held by deferred compensation arrangements at December 31, 2018, and 567,764 shares including 237,494 shares held by deferred compensation arrangements at December 31, 2017)	(11,528)	(21,014)
Deferred compensation arrangements (207,403 shares at December 31, 2018 and 237,494 shares at December 31, 2017)	11,728	13,328
Total shareholders' equity	1,713,783	1,635,315
Total liabilities and shareholders' equity	$ 10,607,295	$ 10,746,198

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets:
Available-for-sale investment securities, cost	$ 2,952,278	$ 3,007,148
Equity and other securities, cost	$ 44,678	$ 50,291
Shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	500,000	500,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	51,576,839	51,263,841
Treasury stock, at cost (in shares)	319,015	567,764
Shares held by deferred compensation arrangements (in shares)	207,403	237,494

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income:
Interest and fees on loans	$ 286,165	$ 253,949	$ 211,467
Interest and dividends on taxable investments	63,504	60,159	56,201
Interest and dividends on nontaxable investments	13,064	15,347	17,519
Total interest income	362,733	329,455	285,187
Interest expense:
Interest on deposits	10,658	8,031	7,325
Interest on borrowings	2,343	1,845	1,017
Interest on subordinated debt held by unconsolidated subsidiary trusts	4,677	3,904	2,949
Total interest expense	17,678	13,780	11,291
Net interest income	345,055	315,675	273,896
Provision for loan losses	10,837	10,984	8,076
Net interest income after provision for loan losses	334,218	304,691	265,820
Noninterest revenues:
Deposit service fees	70,384	67,896	58,595
Other banking revenues	4,968	5,466	7,477
Employee benefit services	92,279	80,830	46,628
Insurance services	30,317	26,150	23,149
Wealth management services	25,772	22,079	19,776
Unrealized gain on equity securities	657	0	0
Loss on debt extinguishment	(318)	0	0
Gain on sales of investment securities, net	0	2	0
Total noninterest revenues	224,059	202,423	155,625
Noninterest expenses:
Salaries and employee benefits	207,363	186,903	156,396
Occupancy and equipment	39,948	35,561	30,078
Data processing and communications	39,094	37,579	34,501
Amortization of intangible assets	18,155	16,941	5,479
Legal and professional fees	10,644	11,576	8,455
Business development and marketing	9,383	9,994	7,484
Acquisition expenses	(769)	25,986	1,706
Other expenses	21,471	22,609	22,749
Total noninterest expenses	345,289	347,149	266,848
Income before income taxes	212,988	159,965	154,597
Income taxes	44,347	9,248	50,785
Net income	$ 168,641	$ 150,717	$ 103,812
Basic earnings per share (in dollars per share)	$ 3.28	$ 3.07	$ 2.34
Diluted earnings per share (in dollars per share)	3.24	3.03	2.32
Cash dividends declared per share (in dollars per share)	$ 1.44	$ 1.32	$ 1.26

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension and other post retirement obligations:
Amortization of actuarial (losses)/gains included in net periodic pension cost, gross	$ (12,647)	$ (707)	$ 5,514
Tax effect	3,087	263	(2,108)
Amortization of actuarial (losses)/gains included in net periodic pension cost, net	(9,560)	(444)	3,406
Amortization of prior service cost included in net periodic pension cost, gross	(1,398)	(859)	(136)
Tax effect	340	324	52
Amortization of prior service cost included in net periodic pension cost, net	(1,058)	(535)	(84)
Initial projected benefit obligation recognized upon plan adoption, gross	(775)	0	0
Tax effect	189	0	0
Initial projected benefit obligation recognized upon plan adoption, net	(586)	0	0
Unamortized actuarial gain due to plan merger, gross	0	1,858	0
Tax effect	0	(711)	0
Unamortized actuarial gain due to plan merger, net	0	1,147	0
Other comprehensive (loss)/income related to pension and other post retirement obligations, net of taxes	(11,204)	168	3,322
Unrealized (losses)/gains on securities:
Net unrealized holding (losses) arising during period, gross	(39,894)	(17,851)	(24,042)
Tax effect	9,700	6,787	9,328
Net unrealized holding losses arising during period, net	(30,194)	(11,064)	(14,714)
Reclassification of other comprehensive income due to change in accounting principle - equity securities	(208)	0	0
Reclassification adjustment for net (gains) included in net income, gross	0	(2)	0
Tax effect	0	1	0
Reclassification adjustment for net gains included in net income, net	0	(1)	0
Other comprehensive (loss) related to unrealized (losses)/gains on available-for-sale securities, net of taxes	(30,402)	(11,065)	(14,714)
Other comprehensive (loss), net of tax	(41,606)	(10,897)	(11,392)
Net income	168,641	150,717	103,812
Comprehensive income	127,035	139,820	92,420
Accumulated Other Comprehensive Income/(Loss) By Component:
Unrealized (loss) for pension and other postretirement obligations	(43,497)	(28,677)	(28,969)
Tax effect	10,660	7,044	11,008
Net unrealized (loss) for pension and other postretirement obligations	(32,837)	(21,633)	(17,961)
Unrealized (loss) gain on available-for-sale securities	(16,229)	23,940	41,793
Tax effect	3,969	(6,006)	(15,989)
Reclassification of other comprehensive income due to change in accounting principle - equity securities	(208)	0	0
Net unrealized (loss) gain on available-for-sale securities	(12,468)	17,934	25,804
Accumulated other comprehensive (loss)/income	$ (45,305)	$ (3,699)	$ 7,843

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock Outstanding [Member]	Common Stock Amount Issued [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Treasury Stock [Member]	Deferred Compensation Arrangements [Member]	Total
Balance at Dec. 31, 2015		$ 44,443	$ 528,015	$ 566,591	$ 19,235	$ (17,637)	$ 0	$ 1,140,647
Balance (in shares) at Dec. 31, 2015	43,774,860
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				103,812				103,812
Other comprehensive income (loss), net of tax					(11,392)			(11,392)
Dividends declared:
Common				(55,711)				(55,711)
Common stock issued under employee stock plan		507	10,036					10,543
Common stock issued under employee stock plan (in shares)	507,784
Stock-based compensation			4,783					4,783
Treasury stock purchased						(3,470)		(3,470)
Treasury stock purchased (in shares)	(67,826)
Treasury stock issued to benefit plan			2,941			5,947		8,888
Treasury stock issued to benefit plan (in shares)	222,597
Balance at Dec. 31, 2016		44,950	545,775	614,692	7,843	(15,160)	0	1,198,100
Balance (in shares) at Dec. 31, 2016	44,437,415
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				150,717				150,717
Other comprehensive income (loss), net of tax					(10,897)			(10,897)
Reclassification related to tax effect of Tax Cuts and Jobs Act				645	(645)			0
Dividends declared:
Common				(65,497)				(65,497)
Common stock issued under employee stock plan		265	4,298					4,563
Common stock issued under employee stock plan (in shares)	264,640
Stock-based compensation			5,137					5,137
Stock issued for acquisitions		6,049	337,083					343,132
Stock issued for acquisitions (in shares)	6,048,849
Deferred compensation arrangements acquired						(10,022)	10,022	$ 0
Deferred compensation arrangements acquired (in shares)	(179,003)
Treasury stock purchased (in shares)								0
Treasury stock purchased						(3,306)	3,306	$ 0
Treasury stock purchased (in shares)	(58,491)
Treasury stock issued to benefit plan			2,586			7,474	0	10,060
Treasury stock issued to benefit plan (in shares)	182,667
Balance at Dec. 31, 2017		51,264	894,879	700,557	(3,699)	(21,014)	13,328	1,635,315
Balance (in shares) at Dec. 31, 2017	50,696,077
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle - equity securities				208	(208)			0
Net income				168,641				168,641
Other comprehensive income (loss), net of tax					(41,398)			(41,398)
Dividends declared:
Common				(73,843)				(73,843)
Common stock issued under employee stock plan		313	6,130					6,443
Common stock issued under employee stock plan (in shares)	312,998
Stock-based compensation			6,064					6,064
Distribution of stock under deferred compensation arrangements						1,898	(1,898)	$ 0
Distribution of stock under deferred compensation arrangements (in shares)	35,233
Treasury stock purchased (in shares)								0
Treasury stock purchased						(298)	298	$ 0
Treasury stock purchased (in shares)	(5,142)
Treasury stock issued to benefit plan			4,675			7,886	0	12,561
Treasury stock issued to benefit plan (in shares)	218,658
Balance at Dec. 31, 2018		$ 51,577	$ 911,748	$ 795,563	$ (45,305)	$ (11,528)	$ 11,728	$ 1,713,783
Balance (in shares) at Dec. 31, 2018	51,257,824

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / shares
Cash dividends declared:
Dividends declared per common share (in dollars per share) | $ / shares	$ 1.26
Common stock issued under employee stock plan, tax benefits | $	$ 3,091

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities:
Net income	$ 168,641	$ 150,717	$ 103,812
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	15,749	16,024	14,398
Amortization of intangible assets	18,155	16,941	5,479
Net accretion on securities, loans and borrowings	(9,404)	(6,619)	(4,405)
Stock-based compensation	6,064	5,137	4,783
Provision for loan losses	10,837	10,984	8,076
Provision/(benefit) for deferred income taxes	2,663	(28,692)	13,066
Amortization of mortgage servicing rights	449	499	518
Unrealized gain on equity securities	(657)	0	0
Loss on debt extinguishment	318	0	0
Income from bank-owned life insurance policies	(1,579)	(1,586)	(1,505)
Gain on sales of investment securities, net	0	(2)	0
Net (gain)/loss on sale of loans and other assets	(80)	181	(837)
Change in other assets and liabilities	10,252	26,090	(7,614)
Net cash provided by operating activities	221,408	189,674	135,771
Investing activities:
Proceeds from maturities, calls and paydowns of available-for-sale investment securities	140,784	157,278	109,638
Proceeds from maturities and redemptions of other investment securities	5,867	30,116	8,703
Purchases of available-for-sale investment securities	(78,131)	(90,380)	(65,966)
Purchases of equity and other securities	(31)	(13,302)	(4,612)
Net (increase) decrease in loans	(35,414)	164,846	(159,871)
Cash paid for acquisition, net of cash acquired of $16, $52,132, and $0, respectively	(1,737)	(107,414)	(575)
Settlement of bank-owned life insurance policies	0	1,779	3,127
Purchases of premises and equipment, net	(12,646)	(10,819)	(12,442)
Real estate limited partnership investments	(1,197)	(733)	0
Net cash provided by/(used in) investing activities	17,495	131,371	(121,998)
Financing activities:
Net change in deposits	(122,049)	(79,940)	202,480
Net decrease in borrowings, net of payments of $95, $81,544 and $0	(47,339)	(144,809)	(155,100)
Payments on subordinated debt held by unconsolidated subsidiary trusts	(25,207)	0	0
Issuance of common stock	6,443	4,563	10,543
Purchase of treasury stock	(298)	(3,306)	(3,470)
Sale of treasury stock	12,561	10,060	8,888
Increase in deferred compensation arrangements	298	3,306	0
Cash dividends paid	(71,495)	(62,305)	(55,048)
Withholding taxes paid on share-based compensation	(1,021)	(1,433)	(1,419)
Net cash (used in)/provided by financing activities	(248,107)	(273,864)	6,874
Change in cash and cash equivalents	(9,204)	47,181	20,647
Cash and cash equivalents at beginning of year	221,038	173,857	153,210
Cash and cash equivalents at end of year	211,834	221,038	173,857
Supplemental disclosures of cash flow information:
Cash paid for interest	17,926	13,705	11,268
Cash paid for income taxes	30,266	41,231	32,239
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	19,808	17,460	14,268
Transfers from loans to other real estate	3,299	3,518	2,612
Acquisitions:
Common stock issued	0	343,132	0
Fair value of assets acquired, excluding acquired cash and intangibles	115	1,961,246	0
Fair value of liabilities assumed	$ 31	$ 1,870,449	$ 0

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investing activities:
Cash acquired related to acquisition	$ 16	$ 52,132	$ 0
Financing activities:
Payment made on borrowings	$ 95	$ 81,544	$ 0

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2018
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Nature of Operations Community Bank System, Inc. (the “Company”) is a registered financial holding company which wholly-owns two significant consolidated subsidiaries: Community Bank, N.A. (the “Bank” or “CBNA”), and Benefit Plans Administrative Services, Inc. (“BPAS”). As of December 31, 2018, BPAS owns five subsidiaries: Benefit Plans Administrative Services, LLC (“BPA”), a provider of defined benefit contribution plan administration services; Northeast Retirement Services, LLC (“NRS”), a provider of institutional transfer agency, master recordkeeping services, fund administration, trust and retirement plan services; BPAS Actuarial & Pension Services, LLC (“BPAS-APS”), a provider of actuarial and benefit consulting services; BPAS Trust Company of Puerto Rico, a Puerto Rican trust company; and Hand Benefits & Trust Company (“HB&T”), a provider of collective investment fund administration and institutional trust services. NRS owns one subsidiary, Global Trust Company, Inc. (“GTC”), a non-depository trust company which provides fiduciary services for collective investment trusts and other products. HB&T owns one subsidiary, Hand Securities Inc. (“HSI”), an introducing broker-dealer. The Company also wholly-owns two unconsolidated subsidiary business trusts formed for the purpose of issuing mandatorily-redeemable preferred securities which are considered Tier I capital under regulatory capital adequacy guidelines (see Note P). As of December 31, 2018, the Bank operated 224 full service branches operating as Community Bank, N.A. throughout 35 counties of Upstate New York, six counties of Northeastern Pennsylvania, 12 counties of Vermont and one county of Western Massachusetts, offering a range of commercial and retail banking services. The Bank owns the following operating subsidiaries: The Carta Group, Inc. (“Carta Group”), CBNA Preferred Funding Corporation (“PFC”), CBNA Treasury Management Corporation (“TMC”), Community Investment Services, Inc. (“CISI”), NOTCH Investment Fund, LLC (“NOTCH”), Nottingham Advisors, Inc. (“Nottingham”), OneGroup NY, Inc. (“OneGroup”), and Oneida Preferred Funding II LLC (“OPFC II”). OneGroup is a full-service insurance agency offering personal and commercial property insurance and other risk management products and services. NOTCH, PFC and OPFC II primarily act as investors in residential and commercial real estate activities. TMC provides cash management, investment, and treasury services to the Bank. CISI and Carta Group provide broker-dealer and investment advisory services. Nottingham provides asset management services to individuals, corporations, corporate pension and profit sharing plans, and foundations. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Variable Interest Entities (“VIE”) are legal entities in which equity investors do not have the characteristics of a controlling financial interest or do not have sufficient equity at risk for the legal entities to finance its activities without additional subordinated financial support. VIEs may be required to be consolidated by a company if it is determined the company is the primary beneficiary of a VIE. The primary beneficiary of a VIE is the enterprise that has: (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance, and (2) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits of the VIE that could potentially be significant to the VIE. The Company’s VIE’s are described in more detail in Note T to the consolidated financial statements. Critical Accounting Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Critical accounting estimates include the allowance for loan losses, actuarial assumptions associated with the pension, post-retirement and other employee benefit plans, the provision for income taxes, investment valuation and other-than-temporary impairment, the carrying value of goodwill and other intangible assets, and acquired loan valuations. Risk and Uncertainties In the normal course of its business, the Company encounters economic and regulatory risks. There are three main components of economic risk: interest rate risk, credit risk and market risk. The Company is subject to interest rate risk to the degree that its interest-bearing liabilities mature or reprice at different speeds, or on different basis, from its interest-earning assets. The Company’s primary credit risk is the risk of default on the Company’s loan portfolio that results from the borrowers’ inability or unwillingness to make contractually required payments. Market risk reflects potential changes in the value of collateral underlying loans, the fair value of investment securities, and loans held for sale. The Company is subject to regulations of various governmental agencies. These regulations can change significantly from period to period. The Company also undergoes periodic examinations by the regulatory agencies which may subject it to further changes with respect to asset valuations, amounts of required loan loss allowances, and operating restrictions resulting from the regulators’ judgments based on information available to them at the time of their examinations. Revenue Recognition On January 1, 2018, the Company adopted ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities. In addition, certain noninterest income streams such as fees associated with mortgage servicing rights, financial guarantees, derivatives, and certain credit card fees are also not in scope of the newly adopted guidance. Topic 606 is applicable to the Company’s noninterest revenue streams including its deposit related fees, electronic payment interchange fees, merchant income, trust, asset management and other wealth management revenues, insurance commissions and benefit plan services income. However, the recognition of these revenue streams did not change significantly upon adoption of Topic 606. Noninterest revenue streams in-scope of Topic 606 are discussed below. Deposit Service Fees Deposit service fees consist of account activity fees, monthly service fees, check orders, debit and credit card income, ATM fees, Merchant services income and other revenues from processing wire transfers, bill pay service, cashier’s checks and foreign exchange. Debit and credit card income is primarily comprised of interchange fees earned at the time the Company’s debit and credit cards are processed through card payment networks such as Visa. ATM fees are primarily generated when a Company cardholder uses a non-Company ATM or a non-Company cardholder uses a Company ATM. Merchant services income mainly represents fees charged to merchants to process their debit and credit card transactions, in addition to account management fees. The Company’s performance obligation for deposit service fees is generally satisfied, and the related revenue recognized, when the services are rendered or the transaction has been completed. Payment for deposit service fees is typically received at the time it is assessed through a direct charge to customers’ accounts or on a monthly basis. Deposit service fees revenue primarily relates to the Company’s Banking operating segment. Other Banking Services Other banking services consists of other recurring revenue streams such as commissions from sales of credit life insurance, safe deposit box rental fees, mortgage banking income, bank owned life insurance income and other miscellaneous revenue streams. Commissions from the sale of credit life insurance are recognized at the time of sale of the policies. Safe deposit box rental fees are charged to the customer on an annual basis and recognized upon receipt of payment. The Company determined that since rentals and renewals occur fairly consistently over time, revenue is recognized on a basis consistent with the duration of the performance obligation. Mortgage banking income and bank owned life insurance income are not within the scope of Topic 606. Other banking services revenue primarily relates to the Company’s Banking operating segment. Employee Benefit Services Employee benefit services income consists of revenue received from retirement plan services, collective investment fund services, fund administration, transfer agency, consulting and actuarial services. The Company’s performance obligation that relates to plan services are satisfied over time and the resulting fees are recognized monthly or quarterly, based upon the market value of the assets under management and the applicable fee rate or on a time expended basis. Payment is generally received a few days after month end or quarter end. The Company does not earn performance-based incentives. Transactional services such as consulting services, mailings, or other ad hoc services are provided to existing trust and asset management customers. The Company’s performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e., as incurred). Payment is received shortly after services are rendered. Employee benefit services revenue primarily relates to the Company’s Employee Benefit Services operating segment. Insurance Services Insurance services primarily consists of commissions received on insurance product sales and consulting services. The Company acts in the capacity of a broker or agent between the Company’s customer and the insurance carrier. The Company’s performance obligation related to insurance sales for both property and casualty insurance and employee benefit plans is generally satisfied upon the later of the issuance or effective date of the policy. The Company’s performance obligation related to consulting services is considered transactional in nature and is generally satisfied when the services have been completed and related revenue recognized at a point in time. Payment is received at the time services are rendered. The Company earns performance based incentives, commonly known as contingency payments, which usually are based on certain criteria established by the insurance carrier such as premium volume, growth and insured loss ratios. Contingent payments are accrued for based upon management’s expectations for the year. Commission expense associated with sales of insurance products is expensed as incurred. Insurance services revenue primarily relates to the Company’s All Other operating segment. Wealth Management Services Wealth management services income is primarily comprised of fees earned from the management and administration of trusts and other customer assets. The Company generally has two types of performance obligations related to these services. The Company’s performance obligation that relates to advisory and administration services are satisfied over time and the resulting fees are recognized monthly, based upon the market value of the assets under management and the applicable fee rate. Payment is generally received soon after month end or quarter end through a direct charge to customers’ accounts. The Company does not earn performance-based incentives. Transactional services such as tax return preparation services, purchases and sales of investments and insurance products are also available to existing trust and asset management customers. The Company’s performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e. as incurred). Payment is generally received on a monthly basis. Wealth management services revenue primarily relates to the Company’s All Other operating segment. Contract Balances A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration (resulting in a contract receivable) or before payment is due (resulting in a contract asset). A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment (or payment is due) from the customer. The Company’s noninterest revenue streams are largely based on transactional activity, or standard month-end revenue accruals such as asset management fees based on month-end market values. Consideration is often received immediately or shortly after the Company satisfies its performance obligation and revenue is recognized. The Company does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances. As of December 31, 2018, $26.4 million of accounts receivable, including $7.8 million of unbilled fee revenue, and $2.2 million of unearned revenue was recorded in the Consolidated Statements of Condition. As of December 31, 2017, $29.8 million of accounts receivable, including $6.5 million of unbilled fee revenue, and $3.9 million of unearned revenue was recorded in the Consolidated Statements of Condition. Contract Acquisition Costs In connection with the adoption of Topic 606, an entity is required to capitalize, and subsequently amortize into expense, certain incremental costs of obtaining a contract with a customer if these costs are expected to be recovered. The incremental costs of obtaining a contract are those costs that an entity incurs to obtain a contract with a customer that it would not have incurred if the contract had not been obtained (for example, sales commission). The Company utilizes the practical expedient method which allows entities to immediately expense contract acquisition costs when the asset that would have resulted from capitalizing these costs would have been amortized in one year or less. Upon adoption of Topic 606, the Company did not capitalize any contract acquisition costs. Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, and highly liquid investments with original maturities of less than 90 days. The carrying amounts reported in the consolidated statements of condition for cash and cash equivalents approximate those assets’ fair values. As of December 31, 2018 and 2017, cash and cash equivalents reported in the consolidated statements of condition included cash due from banks of $15.0 million and $36.0 million, respectively. Investment Securities The Company can classify its investments in debt securities as held-to-maturity, available-for-sale, or trading. Held-to-maturity securities are those for which the Company has the positive intent and ability to hold until maturity, and are reported at cost, which is adjusted for amortization of premiums and accretion of discounts. The Company did not use the held-to-maturity classification in 2017 or 2018. Available-for-sale debt securities are reported at fair value with net unrealized gains and losses reflected as a separate component of shareholders’ equity, net of applicable income taxes. None of the Company’s investment securities have been classified as trading securities at December 31, 2018. Equity securities with a readily determinable fair value are reported at fair value with net unrealized gains and losses recognized in the consolidated statement of income. Certain equity securities that do not have a readily determinable fair value are stated at cost, less impairment, adjusted for observable price changes in orderly transactions for identical or similar investments of the same issuer. These securities include restricted stock of the Federal Reserve Bank of New York (“Federal Reserve”) and the Federal Home Loan Bank of New York and the Federal Home Loan Bank of Boston (collectively referred to as “FHLB”), as well as other equity securities. Fair values for investment securities are based upon quoted market prices, where available. If quoted market prices are not available, fair values are based upon quoted market prices of comparable instruments, or a discounted cash flow model using market estimates of interest rates and volatility. The Company conducts an assessment of all securities in an unrealized loss An OTTI loss must be recognized for a debt security in an unrealized loss position if there is intent to sell the security or it is more likely than not the Company will be required to sell the security prior to recovery of its amortized cost basis. In this situation, the amount of loss recognized in income is equal to the difference between the fair value and the amortized cost basis of the security. Even if management does not have the intent, and it is not more likely than not that the Company will be required to sell the securities, an evaluation of the expected cash flows to be received is performed to determine if a credit loss has occurred. For debt securities, a critical component of the evaluation for OTTI is the identification of credit-impaired securities, where the Company does not expect to receive cash flows sufficient to recover the entire amortized cost basis of the security. In the event of a credit loss, only the amount of impairment associated with the credit loss would be recognized in income. The portion of the unrealized loss relating to other factors, such as liquidity conditions in the market or changes in market interest rates, is recorded in accumulated other comprehensive loss. The specific identification method is used in determining the realized gains and losses on sales of investment securities and OTTI charges. Premiums and discounts on securities are amortized and accreted, respectively, on the interest method basis over the period to maturity or estimated life of the related security. Purchases and sales of securities are recognized on a trade date basis. Loans Loans are stated at unpaid principal balances, net of unearned income. Mortgage loans held for sale are carried at fair value and are included in loans held for sale on the consolidated statements of condition. Fair values for variable rate loans that reprice frequently are based on carrying values. Fair values for fixed rate loans are estimated using discounted cash flows and interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. The carrying amount of accrued interest approximates its fair value. Interest on loans is accrued and credited to operations based upon the principal amount outstanding. Nonrefundable loan fees and related direct costs are deferred and included in the loan balances where they are amortized over the life of the loan as an adjustment to loan yield using the effective yield method. Premiums and discounts on purchased loans are amortized using the effective yield method over the life of the loans. Acquired loans Acquired loans are initially recorded at their acquisition date fair values. The carryover of allowance for loan losses is prohibited as any credit losses in the loans are included in the determination of the fair value of the loans at the acquisition date. Fair values for acquired loans are based on a discounted cash flow methodology that involves assumptions and judgments as to credit risk, prepayment risk, liquidity risk, default rates, loss severity, payment speeds, collateral values and discount rate. Acquired impaired loans Acquired loans that have evidence of deterioration in credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments are accounted for as impaired loans under ASC 310-30. The excess of undiscounted cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loans using the interest method. The difference between contractually required payments at acquisition and the undiscounted cash flows expected to be collected at acquisition is referred to as the non-accretable discount. The non-accretable discount represents estimated future credit losses and other contractually required payments that the Company does not expect to collect. Subsequent decreases in expected cash flows are recognized as impairments through a charge to the provision for loan losses resulting in an increase in the allowance for loan losses. Subsequent improvements in expected cash flows result in a recovery of previously recorded allowance for loan losses or a reversal of a corresponding amount of the non-accretable discount, which the Company then reclassifies as an accretable discount that is recognized into interest income over the remaining life of the loans using the interest method. Acquired loans that met the criteria for non-accrual of interest prior to acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if the Company can reasonably estimate the timing and amount of the expected cash flows on such loans and if the Company expects to fully collect the new carrying value of the loans. As such, the Company may no longer consider the loan to be non-accrual or non-performing and may accrue interest on these loans, including the impact of any accretable discount. Acquired non-impaired loans Acquired loans that do not meet the requirements under ASC 310-30 are considered acquired non-impaired loans. The difference between the acquisition date fair value and the outstanding balance represents the fair value adjustment for a loan and includes both credit and interest rate considerations. Fair value adjustments may be discounts (or premiums) to a loan’s cost basis and are accreted (or amortized) to net interest income (or expense) over the loan’s remaining life in accordance with ASC 310-20. Fair value adjustments for revolving loans are accreted (or amortized) using a straight line method. Term loans are accreted (or amortized) using the constant effective yield method. Subsequent to the purchase date, the methods used to estimate the allowance for loan losses for the acquired non-impaired loans is consistent with the policy described below. However, the Company compares the net realizable value of the loans to the carrying value, for loans collectively evaluated for impairment. The carrying value represents the net of the loan’s unpaid principal balance and the remaining purchase discount (or premium) that has yet to be accreted (or amortized) into interest income (or interest expense). When the carrying value exceeds the net realizable value, an allowance for loan losses is recognized. Impaired and Other Nonaccrual Loans The Company places a loan on nonaccrual status when the loan becomes 90 days past due (or sooner, if management concludes collection is doubtful), except when, in the opinion of management, it is well-collateralized and in the process of collection. A loan may be placed on nonaccrual status earlier than ninety days past due if there is deterioration in the financial position of the borrower or if other conditions of the loan so warrant. When a loan is placed on nonaccrual status, uncollected accrued interest is reversed against interest income and the amortization of nonrefundable loan fees and related direct costs is discontinued. Interest income during the period the loan is on nonaccrual status is recorded on a cash basis after recovery of principal is reasonably assured. Nonaccrual loans are returned to accrual status when management determines that the borrower’s performance has improved and that both principal and interest are collectible. This generally requires a sustained period of timely principal and interest payments and a well-documented credit evaluation of the borrower’s financial condition. A loan is considered modified in a troubled debt restructuring (“TDR”) when, due to a borrower’s financial difficulties, the Company makes a concession(s) to the borrower that it would not otherwise consider. These modifications may include, among others, an extension for the term of the loan, or granting a period when interest–only payments can be made with the principal payments and interest caught up over the remaining term of the loan or at maturity. Generally, a nonaccrual loan that has been modified in a TDR remains on nonaccrual status for a period of 12 months to demonstrate that the borrower is able to meet the terms of the modified loan. If the borrower’s ability to meet the revised payment schedule is uncertain, the loan remains on nonaccrual status. Regulatory guidance issued by the OCC requires certain loans that have been discharged in Chapter 7 bankruptcy to be reported as TDRs. In accordance with this guidance, loans that have been discharged in Chapter 7 bankruptcy but not reaffirmed by the borrower are classified as TDRs, irrespective of payment history or delinquency status, even if the repayment terms for the loan have not been otherwise modified and the Company’s lien position against the underlying collateral remains unchanged. Pursuant to that guidance, the Company records a charge-off equal to any portion of the carrying value that exceeds the net realizable value of the collateral. Commercial loans greater than $0.5 million are evaluated individually for impairment. A loan is considered impaired, based on current information and events, if it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. The measurement of impaired loans is generally based upon the present value of expected future cash flows or the fair value of the collateral, if the loan is collateral-dependent. The Company’s charge-off policy by loan type is as follows: · Business lending loans are generally charged-off to the extent outstanding principal exceeds the fair value of estimated proceeds from collection efforts, including liquidation of collateral. The charge-off is recognized when the loss becomes reasonably quantifiable. · Consumer installment loans are generally charged-off to the extent outstanding principal exceeds the fair value of collateral, and are recognized by the end of the month in which the loan becomes 90 days past due. · Consumer mortgage and home equity loans are generally charged-off to the extent outstanding principal exceeds the fair value of the property, less estimated costs to sell, and are recognized when the loan becomes 180 days past due. Allowance for Loan Losses Management continually evaluates the credit quality of the Company’s loan portfolio, and performs a formal review of the adequacy of the allowance for loan losses on a quarterly basis. The allowance reflects management’s best estimate of probable losses inherent in the loan portfolio. Determination of the allowance is subjective in nature and requires significant estimates. The Company’s allowance methodology consists of two broad components - general and specific loan loss allocations. The general loan loss allocation is composed of two calculations that are computed on five main loan segments: business lending, consumer direct, consumer indirect, home equity and consumer mortgage. The first calculation is quantitative and determines an allowance level based on the latest 36 months of historical net charge-off data for each loan class (commercial loans exclude balances with specific loan loss allocations). The second calculation is qualitative and takes into consideration eight qualitative environmental factors: levels and trends in delinquencies and impaired loans; levels of and trends in charge-offs and recoveries; trends in volume and terms of loans; effects of any changes in risk selection and underwriting standards, and other changes in lending policies, procedures, and practices; experience, ability, and depth of lending management and other relevant staff; national and local economic trends and conditions; industry conditions; and effects of changes in credit concentrations. A component of the qualitative calculation is the unallocated allowance for loan loss. The qualitative and quantitative calculations are added together to determine the general loan loss allocation. The specific loan loss allocation relates to individual commercial loans that are both greater than $0.5 million and in a nonaccruing status with respect to interest. Specific loan losses are based on discounted estimated cash flows, including any cash flows resulting from the conversion of collateral or collateral shortfalls. The allowance levels computed from the specific and general loan loss allocation methods are combined with unallocated allowances and allowances needed for acquired loans to derive the total required allowance for loan losses to be reflected on the Consolidated Statement of Condition. Loan losses are charged off against the allowance, while recoveries of amounts previously charged off are credited to the allowance. A provision for loan losses is charged to operations based on management’s periodic evaluation of factors previously mentioned. Intangible Assets Intangible assets include core deposit intangibles, customer relationship intangibles and goodwill arising from acquisitions. Core deposit intangibles and customer relationship intangibles are amortized on either an accelerated or straight-line basis over periods ranging from seven to 20 years. The initial and ongoing carrying value of goodwill and other intangible assets is based upon discounted cash flow modeling techniques that require management to make estimates regarding the amount and timing of expected future cash flows. It also requires use of a discount rate that reflects the current return requirements of the market in relation to present risk-free interest rates, required equity market premiums, peer volatility indicators, and company-specific risk indicators. The Company evaluates goodwill for impairment on an annual basis, or more often if events or circumstances indicate there may be impairment. The implied fair value of a reporting unit’s goodwill is compared to its carrying amount and the impairment loss is measured by the excess of the carrying value over fair value. The fair value of each reporting unit is compared to the carrying amount of that reporting unit in order to determine if impairment is indicated. Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation. Computer software costs that are capitalized only include external direct costs of obtaining and installing the software. The Company has not developed any internal use software. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. Useful lives range from three to 10 years for equipment; three to seven years for software and hardware; and 10 to 40 years for building and building improvements. Land improvements are depreciated over 20 years and leasehold improvements are amortized over the shorter of the term of the respective lease plus any optional renewal periods that are reasonably assured or life of the asset. Maintenance and repairs are charged to expense as incurred. Other Real Estate Other real estate owned is comprised of properties acquired through foreclosure, or by deed in lieu of foreclosure. These assets are carried at fair value less estimated costs of disposal. At foreclosure, if the fair value, less estimated costs to sell, of the real estate acquired is less than the Company’s recorded investment in the related loan, a write-down is recognized through a charge to the allowance for loan losses. Any subsequent reduction in value is recognized by a charge to income. Operating costs associated with the properties are charged to expense as incurred. At December 31, 2018 and 2017, other real estate totaled $1.3 million and $1.9 million, respectively, and is included in other assets. Mortgage Servicing Rights Originated mortgage servicing rights are recorded at their fair value at the time of sale of the unde

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2018
ACQUISITIONS [Abstract]
ACQUISITIONS	NOTE B: ACQUISITIONS Subsequent Event/ Pending Acquisition – Kinderhook Bank Corp. On January 22, 2019, the Company announced that it had entered into a definitive agreement to acquire Kinderhook Bank Corp. (“Kinderhook”), parent company of The National Union Bank of Kinderhook headquartered in Kinderhook, New York (See Note V). Subsequent Event – Wealth Resources Network, Inc. On January 2, 2019, the Company, through its subsidiary, CISI, completed its acquisition of certain assets of Wealth Resources Network, Inc. (“Wealth Resources”), a financial services business headquartered in Liverpool, New York (See Note V). On April 2, 2018, the Company, through its subsidiary, BPAS, acquired certain assets of HR Consultants (SA), LLC (“HR Consultants”), a provider of actuarial and benefit consulting services headquartered in Puerto Rico. The Company paid $0.3 million in cash to acquire the assets of HR Consultants and recorded intangible assets of $0.3 million in conjunction with the acquisition. The effects of the acquired assets have been included in the consolidated financial statements since that date. On January 2, 2018, the Company, through its subsidiary, OneGroup, completed its acquisition of certain assets of Penna & Associates Agency, Inc. (“Penna”), an insurance agency headquartered in Johnson City, New York. The Company paid $0.8 million in cash to acquire the assets of Penna, and recorded goodwill in the amount of $0.3 million and a customer list intangible asset of $0.3 million in conjunction with the acquisition. The effects of the acquired assets have been included in the consolidated financial statements since that date. On January 2, 2018, the Company, through its subsidiary, CISI, completed its acquisition of certain assets of Styles Bridges Associates (“Styles Bridges”), a financial services business headquartered in Canton, New York. The Company paid $0.7 million in cash to acquire a customer list from Styles Bridges, and recorded a $0.7 million customer list intangible asset in conjunction with the acquisition. The effects of the acquired assets have been included in the consolidated financial statements since that date. On December 4, 2017, the Company, through its subsidiary, OneGroup, completed its acquisition of Gordon B. Roberts Agency, Inc. (“GBR”), an insurance agency headquartered in Oneonta, New York for $3.7 million in Company stock and cash, comprised of $1.35 million in cash and the issuance of 0.04 million shares of common stock. The transaction resulted in the acquisition of $0.6 million of assets, $0.6 million of other liabilities, goodwill in the amount of $2.1 million and other intangible assets of $1.6 million. The effects of the acquired assets and liabilities have been included in the consolidated financial statements since that date. On November 17, 2017, the Company, through its subsidiary, CISI, completed its acquisition of certain assets of Northeast Capital Management, Inc. (“NECM”), a financial services business headquartered in Wilkes-Barre, Pennsylvania. The Company paid $1.2 million in cash to acquire a customer list from NECM, and recorded a $1.2 million customer list intangible asset in conjunction with the acquisition. The effects of the acquired assets have been included in the consolidated financial statements since that date. On May 12, 2017, the Company completed its acquisition of Merchants Bancshares, Inc. (“Merchants”), parent company of Merchants Bank, headquartered in South Burlington, Vermont, for $345.2 million in Company stock and cash, comprised of $82.9 million in cash and the issuance of 4.68 million shares of common stock. The acquisition extends the Company’s footprint into the Vermont and Western Massachusetts markets with the addition of 31 branch locations in Vermont and one location in Massachusetts. This transaction resulted in the acquisition of $2.0 billion of assets, including $1.49 billion of loans and $370.6 million of investment securities, as well as $1.45 billion of deposits and $189.0 million in goodwill. The effects of the acquired assets and liabilities have been included in the consolidated financial statements since that date. Revenues of approximately $61.2 million and direct expenses, which may not include certain shared expenses, of approximately $30.8 million from Merchants were included in the consolidated income statement for the year ended December 31, 2018. Revenues of approximately $42.6 million and direct expenses, which may not include certain shared expenses, of approximately $19.9 million from Merchants were included in the consolidated income statement for the year ended December 31, 2017. On March 1, 2017, the Company, through its subsidiary, OneGroup, completed its acquisition of certain assets of Dryfoos Insurance Agency, Inc. (“Dryfoos”), an insurance agency headquartered in Hazleton, Pennsylvania. The Company paid $3.0 million in cash to acquire the assets of Dryfoos, and recorded goodwill in the amount of $1.7 million and other intangible assets of $1.7 million in conjunction with the acquisition. The effects of the acquired assets and liabilities have been included in the consolidated financial statements since that date. On February 3, 2017, the Company completed its acquisition of NRS and its subsidiary GTC, headquartered in Woburn, Massachusetts, for $148.6 million in Company stock and cash. NRS was a privately held corporation focused on providing institutional transfer agency, master recordkeeping services, custom target date fund administration, trust product administration and customized reporting services to institutional clients. Its wholly-owned subsidiary, GTC, is chartered in the State of Maine as a non-depository trust company and provides fiduciary services for collective investment trusts and other products. The acquisition of NRS and GTC, hereafter referred to collectively as NRS, strengthens and complements the Company’s existing employee benefit services businesses. Upon the completion of the merger, NRS became a wholly-owned subsidiary of BPAS and operates as Northeast Retirement Services, LLC, a Delaware limited liability company. This transaction resulted in the acquisition of $36.1 million in net tangible assets, principally cash and certificates of deposit, $60.2 million in customer list intangibles that will be amortized using the 150% declining balance method over 10 years, a $23.0 million deferred tax liability associated with the customer list intangible, and $75.3 million in goodwill. The effects of the acquired assets and liabilities have been included in the consolidated financial statements since that date. Revenues of $40.6 million and expenses of $24.6 million from NRS were included in the consolidated statement of income for the year ended December 31, 2018. Revenues of $31.5 million and expenses of $21.5 million from NRS were included in the consolidated statement of income for the year ended December 31, 2017. On January 1, 2017, the Company, through its subsidiary, OneGroup, acquired certain assets of Benefits Advisory Service, Inc. (“BAS”), a benefits consulting group headquartered in Forest Hills, New York. The Company paid $1.2 million in cash to acquire the assets of BAS and recorded intangible assets of $1.2 million in conjunction with the acquisition. The effects of the acquired assets and liabilities have been included in the consolidated financial statements since that date. On January 4, 2016, the Company, through its subsidiary, CBNA Insurance Agency, Inc. (“CBNA Insurance”), completed its acquisition of WJL Agencies Inc. doing business as The Clark Insurance Agencies (“WJL”), an insurance agency operating in Canton, New York. The Company paid $0.6 million in cash for the intangible assets of the company. Goodwill in the amount of $0.3 million and intangible assets in the amount of $0.3 million were recorded in conjunction with the acquisition. The effects of the acquired assets and liabilities have been included in the consolidated financial statements since that date. On August 19, 2016, the Company merged together its insurance subsidiaries and as of that date, the activities of CBNA Insurance were merged into OneGroup. The assets and liabilities assumed in the acquisitions were recorded at their estimated fair values based on management’s best estimates using information available at the dates of the acquisition, and were subject to adjustment based on updated information not available at the time of acquisition. During the first quarter of 2018, the carrying amount of other liabilities associated with the NRS acquisition decreased by $1.2 million as a result of an adjustment to deferred taxes. Goodwill associated with the NRS acquisition decreased $1.2 million as a result of this adjustment. During the second quarter of 2018, the carrying amount of other liabilities associated with the GBR acquisition decreased by $0.09 million as a result of updated information not available at the time of acquisition. Goodwill associated with the GBR acquisition decreased $0.09 million as a result of this adjustment. During the fourth quarter of 2018, the carrying amount of other liabilities associated with the GBR acquisition increased $0.02 million as a result of updated information not available at the time of acquisition. Goodwill associated with the GBR acquisition increased $0.02 million as a result of this adjustment. The above referenced acquisitions generally expanded the Company’s geographical presence in New York, Pennsylvania, Vermont, and Western Massachusetts and management expects that the Company will benefit from greater geographic diversity and the advantages of other synergistic business development opportunities. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed after considering the measurement period adjustments described above: 2018 2017 2016 (000s omitted) Other (1) NRS Merchants Other (2) Total WJL Consideration paid : Cash $ 1,753 $ 70,073 $ 82,898 $ 6,775 $ 159,746 $ 575 Community Bank System, Inc. common stock 0 78,483 262,254 2,395 343,132 0 Total net consideration paid $ 1,753 148,556 345,152 9,170 502,878 575 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 16 11,063 40,730 339 52,132 0 Investment securities 0 20,294 370,648 0 390,942 0 Loans 0 0 1,488,157 0 1,488,157 0 Premises and equipment 10 411 16,608 27 17,046 0 Accrued interest receivable 0 72 4,773 0 4,845 0 Other assets 105 8,088 51,585 583 60,256 0 Core deposit intangibles 0 0 23,214 0 23,214 0 Other intangibles 1,343 60,200 2,857 5,626 68,683 288 Deposits 0 0 (1,448,406 ) 0 (1,448,406 ) 0 Other liabilities (31 ) (26,828 ) (11,750 ) (1,155 ) (39,733 ) 0 Short-term advances 0 0 (80,000 ) 0 (80,000 ) 0 Securities sold under agreement to repurchase, short-term 0 0 (278,076 ) 0 (278,076 ) 0 Long-term debt 0 0 (3,615 ) 0 (3,615 ) 0 Subordinated debt held by unconsolidated subsidiary trusts 0 0 (20,619 ) 0 (20,619 ) 0 Total identifiable assets, net 1,443 73,300 156,106 5,420 234,826 288 Goodwill $ 310 $ 75,256 $ 189,046 $ 3,750 $ 268,052 $ 287 (1) (2) Includes amounts related to the BAS, Dryfoos, NECM and GBR acquisitions. Acquired loans that have evidence of deterioration in credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments were aggregated by comparable characteristics and recorded at fair value without a carryover of the related allowance for loan losses. Cash flows for each loan were determined using an estimate of credit losses and rate of prepayments. Projected monthly cash flows were then discounted to present value using a market-based discount rate. The excess of the undiscounted expected cash flows over the estimated fair value is referred to as the “accretable yield” and is recognized into interest income over the remaining lives of the acquired loans. The following is a summary of the loans acquired from Merchants at the date of acquisition: Acquired Acquired Total Impaired Non-impaired Acquired (000s omitted) Loans Loans Loans Contractually required principal and interest at acquisition $ 15,454 $ 1,872,574 $ 1,888,028 Contractual cash flows not expected to be collected (5,385 ) (14,753 ) (20,138 ) Expected cash flows at acquisition 10,069 1,857,821 1,867,890 Interest component of expected cash flows (793 ) (378,940 ) (379,733 ) Fair value of acquired loans $ 9,276 $ 1,478,881 $ 1,488,157 The fair value of checking, savings and money market deposit accounts acquired were assumed to approximate the carrying value as these accounts have no stated maturity and are payable on demand. Certificate of deposit accounts were valued at the present value of the certificates’ expected contractual payments discounted at market rates for similar certificates. The core deposit intangibles and other intangibles related to the Penna, Styles Bridges, HR Consultants, Merchants, Dryfoos, BAS, NECM, GBR, and WJL acquisitions are being amortized using an accelerated method over their estimated useful life of eight years. The goodwill, which is not amortized for book purposes, was assigned to the Banking segment for the Merchants acquisition, the Employee Benefit Services segment for NRS, and All Other segments for the Penna, Dryfoos, BAS, GBR, and WJL acquisitions. Goodwill arising from the Merchants, NRS, and GBR acquisitions is not deductible for tax purposes. Goodwill arising from the Penna, Dryfoos, BAS, GBR, and WJL acquisitions is deductible for tax purposes. Direct costs related to the acquisitions were expensed as incurred. Merger and acquisition integration-related (recoveries) expenses amount to $(0.8) million, $26.0 million and $1.7 million during 2018, 2017 and 2016, respectively, and have been separately stated in the consolidated statements of income. Supplemental Pro Forma Financial Information The following unaudited condensed pro forma information assumes the Merchants and NRS acquisitions had been completed as of January 1, 2016 for the year ended December 31, 2017 and December 31, 2016. The pro forma information does not include amounts related to BAS, Dryfoos, NECM and GBR as the amounts were immaterial. The table below has been prepared for comparative purposes only and is not necessarily indicative of the actual results that would have been attained had the acquisitions occurred as of the beginning of the year presented, nor is it indicative of the Company’s future results. Furthermore, the unaudited pro forma information does not reflect management’s estimate of any revenue-enhancing opportunities nor anticipated cost savings that may have occurred as a result of the integration and consolidation of the acquisitions. The pro forma information set forth below reflects the historical results of Merchants and NRS combined with the Company’s consolidated statement of income with adjustments related to (a) certain purchase accounting fair value adjustments and (b) amortization of customer lists and core deposit intangibles. Acquisition expenses related to the Merchants and NRS transactions totaling $25.7 million for the year ended December 31, 2017 were included in the pro forma information as if they were incurred in 2016. Pro Forma (Unaudited) Year Ended December 31, (000’s omitted) 2017 2016 Total revenue, net of interest expense $ 546,977 $ 536,183 Net income 176,257 109,186

INVESTMENT SECURITIES

INVESTMENT SECURITIES	12 Months Ended
	Dec. 31, 2018
INVESTMENT SECURITIES [Abstract]
INVESTMENT SECURITIES	NOTE C: INVESTMENT SECURITIES The amortized cost and estimated fair value of investment securities as of December 31 are as follows: 2018 2017 (000’s omitted) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale Portfolio: U.S. Treasury and agency securities $ 2,036 , $ 2,190 $ 14,911 $ 2,023 , $ 2,043,023 $ 15,886 $ 4,838 $ 2,054,071 Obligations of state and political subdivisions 453 , 6 , 1,049 459 , 514,949 14,064 57 528,956 Government agency mortgage-backed securities 390 , 1,526 9,283 382 , 358,180 3,121 3,763 357,538 Corporate debt securities 2,588 0 42 2,546 2,648 0 25 2,623 Government agency collateralized mortgage obligations 69 , 60 1,283 68 , 88,097 155 878 87,374 Marketable equity securities 0 0 0 0 251 275 0 526 Total available-for-sale portfolio $ 2,952,278 $ 10 , $ 26 , $ 2,936,049 $ 3,007,148 $ 33,501 $ 9,561 $ 3,031,088 Equity and other Securities: Equity securities, at fair value $ 251 $ 200 $ 19 $ 432 $ 0 $ 0 $ 0 $ 0 Federal Home Loan Bank common stock 8,768 0 0 8,768 9,896 0 0 9,896 Federal Reserve Bank common stock 30,690 0 0 30,690 30,690 0 0 30,690 Certificates of deposit 0 0 0 0 3,865 0 0 3,865 Other equity securities, at adjusted cost 4 , 750 0 5,719 5,840 0 0 5,840 Total equity and other securities $ 44 , $ 950 $ 19 $ 45 , $ 50,291 $ 0 $ 0 $ 50,291 A summary of investment securities that have been in a continuous unrealized loss position for less than or greater than twelve months is as follows: As of December 31, 2018 Less than 12 Months 12 Months or Longer Total (000’s omitted) # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses Available-for-Sale Portfolio: U.S. Treasury and agency securities 7 $ 473,082 $ 682 64 $ 1,213,276 $ 14,229 71 $ 1,686,358 $ 14,911 Obligations of state and political subdivisions 118 55,671 216 97 51,753 833 215 107,424 1,049 Government agency mortgage-backed securities 43 47,708 258 181 253,931 9,025 224 301,639 9,283 Corporate debt securities 0 0 0 1 2,546 42 1 2,546 42 Government agency collateralized mortgage obligations 1 66 0 41 63,112 1,283 42 63,178 1,283 Total available-for-sale investment portfolio 169 $ 576,527 $ 1,156 384 $ 1,584,618 $ 25,412 553 $ 2,161,145 $ 26,568 Equity and other Securities: Equity securities, at fair value 1 $ 82 $ 19 0 $ 0 $ 0 1 $ 82 $ 19 Total equity and other securities 1 $ 82 $ 19 0 $ 0 $ 0 1 $ 82 $ 19 As of December 31, 2017 Less than 12 Months 12 Months or Longer Total (000’s omitted) # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses Available-for-Sale Portfolio: U.S. Treasury and agency securities 44 $ 699,709 $ 4,838 0 $ 0 $ 0 44 $ 699,709 $ 4,838 Obligations of state and political subdivisions 45 23,432 57 0 0 0 45 23,432 57 Government agency mortgage-backed securities 120 185,716 1,433 55 75,712 2,330 175 261,428 3,763 Corporate debt securities 1 2,623 25 0 0 0 1 2,623 25 Government agency collateralized mortgage obligations 39 80,041 878 1 1 0 40 80,042 878 Total available-for-sale investment portfolio 249 $ 991,521 $ 7,231 56 $ 75,713 $ 2,330 305 $ 1,067,234 $ 9,561 The unrealized losses reported pertaining to securities issued by the U.S. government and its sponsored entities, include treasuries, agencies, and mortgage-backed securities issued by Ginnie Mae, Fannie Mae, and Freddie Mac which are currently rated AAA by Moody’s Investor Services, AA+ by Standard & Poor’s and are guaranteed by the U.S. government. The majority of the obligations of state and political subdivisions and corporations carry a credit rating of A or better. Additionally, a majority of the obligations of state and political subdivisions carry a secondary level of credit enhancement. The Company does not intend to sell these securities, nor is it more likely than not that the Company will be required to sell these securities prior to recovery of the amortized cost. The unrealized losses in the portfolios are primarily attributable to changes in interest rates. As such, management does not believe any individual unrealized loss as of December 31, 2018 represents OTTI. The amortized cost and estimated fair value of debt securities at December 31, 2018, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. Available-for-Sale (000’s omitted) Amortized Cost Fair Value Due in one year or less $ 58 , $ 58 , Due after one through five years 2 , , 2 , , Due after five years through ten years 158 , 160 , Due after ten years 149 , 151 , Subtotal 2,492 , 2,485 , Government agency mortgage-backed securities 390,234 382,477 Government agency collateralized mortgage obligations 69,342 68,119 Total $ 2 , , $ 2 , , Investment securities with a carrying value of $1.447 billion and $1.530 billion at December 31, 2018 and 2017, respectively, were pledged to collateralize certain deposits and borrowings. Securities pledged to collateralize certain deposits and borrowings included $492.4 million and $473.2 million of U.S. Treasury securities that were pledged as collateral for securities sold under agreement to repurchase at December 31, 2018, and 2017, respectively. All securities sold under agreement to repurchase as of December 31, 2018 and 2017 have an overnight and continuous maturity.

LOANS

LOANS	12 Months Ended
	Dec. 31, 2018
LOANS [Abstract]
LOANS	NOTE D: LOANS The segments of the Company’s loan portfolio are disaggregated into the following classes that allow management to monitor risk and performance: · Consumer mortgages consist primarily of fixed rate residential instruments, typically 10 – 30 years in contractual term, secured by first liens on real property. · Business lending is comprised of general purpose commercial and industrial loans including, but not limited to agricultural-related and dealer floor plans, as well as mortgages on commercial property. · Consumer indirect consists primarily of installment loans originated through selected dealerships and are secured by automobiles, marine and other recreational vehicles. · Consumer direct consists of all other loans to consumers such as personal installment loans and lines of credit. · Home equity products are consumer purpose installment loans or lines of credit most often secured by a first or second lien position on residential real estate with terms up to 30 years. The balances of these classes at December 31 are summarized as follows: (000’s omitted) 2018 2017 Business lending $ 2,396,977 $ 2,424,223 Consumer mortgage 2,235,408 2,220,298 Consumer indirect 1,083,207 1,011,978 Consumer direct 178,820 179,929 Home equity 386,709 420,329 Gross loans, including deferred origination costs 6,281,121 6,256,757 Allowance for loan losses (49,284 ) (47,583 ) Loans, net of allowance for loan losses $ 6,231,837 $ 6,209,174 The Company had approximately $28.4 million and $25.3 million of net deferred loan origination costs included in gross loans as of December 31, 2018 and 2017, respectively. Certain directors and executive officers of the Company, as well as associates of such persons, are loan customers. Loans to these individuals were made in the ordinary course of business under normal credit terms and do not have more than a normal risk of collection. Following is a summary of the aggregate amount of such loans during 2018 and 2017. (000’s omitted) 2018 2017 Balance at beginning of year $ 22,344 $ 10,950 New loans 2,600 16,617 Payments (4,283 ) (5,223 ) Balance at end of year $ 20,661 $ 22,344 Acquired loans Acquired loans are recorded at fair value as of the date of purchase with no allowance for loan loss. The outstanding principal balance and the related carrying amount of acquired loans included in the Consolidated Statement of Condition at December 31 are as follows: (000’s omitted) 2018 2017 Credit impaired acquired loans: Outstanding principal balance $ 6,936 $ 13,242 Carrying amount 5,446 10,115 Non-impaired acquired loans: Outstanding principal balance 1,271 , 1,658,780 Carrying amount 1,247 , 1,626,979 Total acquired loans: Outstanding principal balance 1,278 , 1,672,022 Carrying amount 1,253,137 1,637,094 The outstanding balance related to credit impaired acquired loans was $7.0 million and $13.4 million at December 31, 2018 and 2017, respectively. The changes in the accretable discount related to the credit impaired acquired loans are as follows: (000’s omitted) 2018 2017 Balance at beginning of year $ 976 $ 498 Merchants acquisition 0 793 Accretion recognized (783 ) (905 ) Net reclassification to accretable from nonaccretable 244 590 Balance at end of year $ 437 $ 976 Credit Quality Management monitors the credit quality of its loan portfolio on an ongoing basis. Measurement of delinquency and past due status are based on the contractual terms of each loan. Past due loans are reviewed on a monthly basis to identify loans for non-accrual status. The following is an aged analysis of the Company’s past due loans by class as of December 31, 2018: Legacy Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Current Total Loans Business lending $ 5,261 $ 179 $ 4,872 $ 10,312 $ 1,608,515 $ 1,618,827 Consumer mortgage 12,468 1,393 9,872 23,733 1,824,717 1,848,450 Consumer indirect 14,609 258 0 14,867 1,057,525 1,072,392 Consumer direct 1,778 48 0 1,826 173,948 175,774 Home equity 983 228 1,438 2,649 309,892 312,541 Total $ 35,099 $ 2,106 $ 16,182 $ 53,387 $ 4,974,597 $ 5,027,984 Acquired Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Acquired Impaired (1) Current Total Loans Business lending $ 974 $ 0 $ 3,498 $ 4,472 $ 5,446 $ 768,232 $ 778,150 Consumer mortgage 841 232 2,390 3,463 0 383,495 386,958 Consumer indirect 78 34 0 112 0 10,703 10,815 Consumer direct 115 4 0 119 0 2,927 3,046 Home equity 613 79 474 1,166 0 73,002 74,168 Total $ 2,621 $ 349 $ 6,362 $ 9,332 $ 5,446 $ 1,238,359 $ 1,253,137 (1) Acquired impaired loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cashflows, is being recognized on all acquired impaired loans. The following is an aged analysis of the Company’s past due loans by class as of December 31, 2017: Legacy Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Still Accruing Nonaccrual Total Past Due Current Total Loans Business lending $ 2,283 $ 571 $ 3,944 $ 6,798 $ 1,369,801 $ 1,376,599 Consumer mortgage 13,564 1,500 10,722 25,786 1,728,823 1,754,609 Consumer indirect 14,197 295 0 14,492 977,344 991,836 Consumer direct 1,875 48 0 1,923 172,556 174,479 Home equity 1,116 94 1,354 2,564 319,576 322,140 Total $ 33,035 $ 2,508 $ 16,020 $ 51,563 $ 4,568,100 $ 4,619,663 Acquired Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Acquired (1) Current Total Loans Business lending $ 4,661 $ 0 $ 4,328 $ 8,989 $ 10,115 $ 1,028,520 $ 1,047,624 Consumer mortgage 2,603 26 3,066 5,695 0 459,994 465,689 Consumer indirect 245 8 0 253 0 19,889 20,142 Consumer direct 100 0 0 100 0 5,350 5,450 Home equity 634 170 1,326 2,130 0 96,059 98,189 Total $ 8,243 $ 204 $ 8,720 $ 17,167 $ 10,115 $ 1,609,812 $ 1,637,094 (1) Acquired impaired loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cashflows, is being recognized on all acquired impaired loans. The Company uses several credit quality indicators to assess credit risk in an ongoing manner. The Company’s primary credit quality indicator for its business lending portfolio is an internal credit risk rating system that categorizes loans as “pass”, “special mention”, “classified”, or “doubtful”. Credit risk ratings are applied individually to those classes of loans that have significant or unique credit characteristics that benefit from a case-by-case evaluation. In general, the following are the definitions of the Company’s credit quality indicators: Pass The condition of the borrower and the performance of the loans are satisfactory or better. Special Mention The condition of the borrower has deteriorated although the loan performs as agreed. Classified The condition of the borrower has significantly deteriorated and the performance of the loan could further deteriorate if deficiencies are not corrected. Doubtful The condition of the borrower has deteriorated to the point that collection of the balance is improbable based on current facts and conditions. The following table shows the amount of business lending loans by credit quality category: December 31, 2018 December 31, 2017 (000’s omitted) Legacy Acquired Total Legacy Acquired Total Pass $ 1,439,337 $ 702,493 $ 2,141,830 $ 1,170,156 $ 963,981 $ 2,134,137 Special mention 105,065 40,107 145,172 129,076 37,321 166,397 Classified 74,425 28,525 102,950 77,367 34,628 111,995 Doubtful 0 1,579 1,579 0 1,579 1,579 Acquired impaired 0 5,446 5,446 0 10,115 10,115 Total $ 1,618,827 $ 778,150 $ 2,396,977 $ 1,376,599 $ 1,047,624 $ 2,424,223 All other loans are underwritten and structured using standardized criteria and characteristics, primarily payment performance, and are normally risk rated and monitored collectively on a monthly basis. These are typically loans to individuals in the consumer categories and are delineated as either performing or nonperforming. Performing loans include current, 30 – 89 days past due and acquired impaired loans. Nonperforming loans include 90+ days past due and still accruing and nonaccrual loans. The following tables detail the balances in all loan categories except for business lending at December 31, 2018: Legacy loans (000’s omitted) Consumer Mortgage Consumer Consumer Direct Home Equity Total Performing $ 1,837,185 $ 1,072,134 $ 175,726 $ 310,875 $ 3,395,920 Nonperforming 11,265 258 48 1,666 13,237 Total $ 1,848,450 $ 1,072,392 $ 175,774 $ 312,541 $ 3,409,157 Acquired loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 384,336 $ 10,781 $ 3,042 $ 73,615 $ 471,774 Nonperforming 2,622 34 4 553 3,213 Total $ 386,958 $ 10,815 $ 3,046 $ 74,168 $ 474,987 The following table details the balances in all other loan categories at December 31, 2017: Legacy loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 1,742,387 $ 991,541 $ 174,431 $ 320,692 $ 3,229,051 Nonperforming 12,222 295 48 1,448 14,013 Total $ 1,754,609 $ 991,836 $ 174,479 $ 322,140 $ 3,243,064 Acquired loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 462,597 $ 20,134 $ 5,450 $ 96,693 $ 584,874 Nonperforming 3,092 8 0 1,496 4,596 Total $ 465,689 $ 20,142 $ 5,450 $ 98,189 $ 589,470 All loan classes are collectively evaluated for impairment except business lending, as described in Note A. A summary of individually evaluated impaired loans as of December 31, 2018 and 2017 is as follows: (000’s omitted) 2018 2017 Loans with allowance allocation $ 3,956 $ 5,125 Loans without allowance allocation 2,230 884 Carrying balance 6,186 6,009 Contractual balance 12,078 9,165 Specifically allocated allowance 956 804 Average impaired loans 7,618 9,517 Interest income recognized 0 0 In the course of working with borrowers, the Company may choose to restructure the contractual terms of certain loans. In this scenario, the Company attempts to work-out an alternative payment schedule with the borrower in order to optimize collectability of the loan. Any loans that are modified are reviewed by the Company to identify if a troubled debt restructuring (“TDR”) has occurred, which is when, for economic or legal reasons related to a borrower’s financial difficulties, the Company grants a concession to the borrower that it would not otherwise consider. Terms may be modified to fit the ability of the borrower to repay in line with its current financial standing and the restructuring of the loan may include the transfer of assets from the borrower to satisfy the debt, a modification of loan terms, or a combination of the two. With regard to determination of the amount of the allowance for loan losses, troubled debt restructured loans are considered to be impaired. As a result, the determination of the amount of allowance for loan losses related to impaired loans for each portfolio segment within TDRs is the same as detailed previously. In accordance with clarified guidance issued by the OCC, loans that have been discharged in Chapter 7 bankruptcy but not reaffirmed by the borrower, are classified as TDRs, irrespective of payment history or delinquency status, even if the repayment terms for the loan have not been otherwise modified. The Company’s lien position against the underlying collateral remains unchanged. Pursuant to that guidance, the Company records a charge-off equal to any portion of the carrying value that exceeds the net realizable value of the collateral. The amount of loss incurred in 2018, 2017 and 2016 was immaterial. TDRs less than $0.5 million are collectively included in the general loan loss allocation and the qualitative review, if necessary. Commercial loans greater than $0.5 million are individually evaluated for impairment, and if necessary, a specific allocation of the allowance for loan losses is provided. Information regarding TDRs as of December 31, 2018 and December 31, 2017 is as follows December 31, 2018 December 31, 2017 (000’s omitted) Nonaccrual Accruing Total Nonaccrual Accruing Total # Amount # Amount # Amount # Amount # Amount # Amount Business lending 4 $ 162 2 $ 165 6 $ 327 8 $ 218 7 $ 501 15 $ 719 Consumer mortgage 46 1,986 46 1,769 92 3,755 51 2,265 44 1,750 95 4,015 Consumer indirect 0 0 77 857 77 857 0 0 71 883 71 883 Consumer direct 0 0 22 71 22 71 0 0 25 69 25 69 Home equity 12 240 9 275 21 515 13 245 7 204 20 449 Total 62 $ 2,388 156 $ 3,137 218 $ 5,525 72 $ 2,728 154 $ 3,407 226 $ 6,135 The following table presents information related to loans modified in a TDR during the years ended December 31, 2018 and 2017. Of the loans noted in the table below, all loans for the years ended December 31, 2018 and December 31, 2017, were modified due to a Chapter 7 bankruptcy as described previously. The financial effects of these restructurings were immaterial. December 31, 2018 December 31, 2017 (000’s omitted) # Amount # Amount Business lending 2 $ 103 8 $ 412 Consumer mortgage 9 470 23 1,254 Consumer indirect 32 320 33 490 Consumer direct 6 24 6 17 Home equity 3 118 4 95 Total 52 $ 1,035 74 $ 2,268 Allowance for Loan Losses The allowance for loan losses is general in nature and is available to absorb losses from any loan type despite the analysis below. The following presents by class the activity in the allowance for loan losses: (000’s omitted) Business Lending Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Unallocated Acquired Impaired Total Balance at December 31, 2015 $ 15,749 $ 10,198 $ 12,422 $ 2,997 $ 2,666 $ 1,201 $ 168 $ 45,401 Charge-offs (1,872 ) (647 ) (7,643 ) (1,706 ) (218 ) 0 (97 ) (12,183 ) Recoveries 616 115 4,168 901 139 0 0 5,939 Provision 2,727 428 4,835 787 (188 ) (550 ) 37 8,076 Balance at December 31, 2016 17,220 10,094 13,782 2,979 2,399 651 108 47,233 Charge-offs (4,959 ) (707 ) (8,456 ) (2,081 ) (284 ) 0 (270 ) (16,757 ) Recoveries 656 50 4,516 849 52 0 0 6,123 Provision 4,340 1,028 3,626 1,292 (60 ) 449 309 10,984 Balance at December 31, 2017 17,257 10,465 13,468 3,039 2,107 1,100 147 47,583 Charge-offs (3,566 ) (836 ) (8,382 ) (1,777 ) (544 ) 0 (381 ) (15,486 ) Recoveries 485 136 4,874 807 48 0 0 6,350 Provision 4,346 359 4,406 1,026 533 (100 ) 267 10,837 Balance at December 31, 2018 $ 18,522 $ 10,124 $ 14,366 $ 3,095 $ 2,144 $ 1,000 $ 33 $ 49,284

PREMISES AND EQUIPMENT

PREMISES AND EQUIPMENT	12 Months Ended
	Dec. 31, 2018
PREMISES AND EQUIPMENT [Abstract]
PREMISES AND EQUIPMENT	NOTE E: PREMISES AND EQUIPMENT Premises and equipment consist of the following at December 31: (000’s omitted) 2018 2017 Land and land improvements $ 24,340 $ 23,869 Bank premises 133,259 131,647 Equipment and construction in progress 89 , 86,059 Premises and equipment, gross 247,549 241,575 Accumulated depreciation (127 , ) (118,182 ) Premises and equipment, net $ 119 , $ 123,393

GOODWILL AND IDENTIFIABLE INTAN

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2018
GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS [Abstract]
GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	NOTE F: GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS The gross carrying amount and accumulated amortization for each type of identifiable intangible asset are as follows: December 31, 2018 December 31, 2017 (000’s omitted) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizing intangible assets: Core deposit intangibles $ 62,902 $ (44 , ) $ 18 , $ 62,902 $ (37,877 ) $ 25,025 Other intangibles 87,616 (32 , ) 55 , 86,535 (20,902 ) 65,633 Total amortizing intangibles $ 150,518 $ (76 , ) $ 73 , $ 149,437 $ (58,779 ) $ 90,658 The estimated aggregate amortization expense for each of the five succeeding fiscal years ended December 31 is as follows: 2019 $ 15 , 2020 12 , 2021 10 , 2022 9 , 2023 7 , Thereafter 17 , Total $ 73 , Shown below are the components of the Company’s goodwill at December 31, 2018 and 2017: (000’s omitted) Year Ended December 31, 2016 Activity Year Ended December 31, 2017 Activity Year Ended December 31, 2018 Goodwill $ 469,966 $ 269,288 $ 739,254 $ (927 ) $ 738,327 Accumulated impairment (4,824 ) 0 (4,824 ) 0 (4,824 ) Goodwill, net $ 465,142 $ 269,288 $ 734,430 $ (927 ) $ 733,503 During the first quarter of 2018, the Company performed its annual internal valuation of goodwill and impairment analysis by comparing the fair value of each reporting unit to its carrying value. Results of the valuations indicate there was no goodwill impairment. Mortgage Servicing Rights Under certain circumstances, the Company sells consumer residential mortgage loans in the secondary market and typically retains the right to service the loans sold. Generally, the Company’s residential mortgage loans sold to third parties are sold on a non-recourse basis. Upon sale, a mortgage servicing right (“MSR”) is established, which represents the current fair value of future net cash flows expected to be realized for performing the servicing activities. The Company stratifies these assets based on predominant risk characteristics, namely expected term of the underlying financial instruments, and uses a valuation model that calculates the present value of future cash flows to determine the fair value of servicing rights. MSRs are recorded in other assets at the lower of the initial capitalized amount, net of accumulated amortization or fair value. Mortgage loans serviced for others are not included in the accompanying consolidated statements of condition. The following table summarizes the changes in carrying value of MSRs and the associated valuation allowance: (000’s omitted) 2018 2017 Carrying value before valuation allowance at beginning of period $ 1,358 $ 1,435 Additions 228 358 Merchants acquisition 0 64 Amortization (449 ) (499 ) Carrying value before valuation allowance at end of period 1,137 1,358 Valuation allowance balance at beginning of period 0 0 Impairment charges 0 0 Impairment recoveries 0 0 Valuation allowance balance at end of period 0 0 Net carrying value at end of period $ 1,137 $ 1,358 Fair value of MSRs at end of period $ 2,397 $ 2,473 Principal balance of loans sold during the year $ 18,228 $ 32,937 Principal balance of loans serviced for others $ 333,862 $ 358,518 Custodial escrow balances maintained in connection with loans serviced for others $ 4,982 $ 5,363 The following table summarizes the key economic assumptions used to estimate the value of the MSRs at December 31: 2018 2017 Weighted-average contractual life (in years) 21.4 21.3 Weighted-average constant prepayment rate (CPR) 9.3 % 11.1 % Weighted-average discount rate 3.6 % 3.3 %

DEPOSITS

DEPOSITS	12 Months Ended
	Dec. 31, 2018
DEPOSITS [Abstract]
DEPOSITS	NOTE G: DEPOSITS Deposits recorded in the consolidated statements of condition consist of the following at December 31: (000’s omitted) 2018 2017 Noninterest checking $ 2,312 , $ 2,293,057 Interest checking 1,920 , 1,830,914 Savings 1,448,208 1,421,512 Money market 1,901,262 2,124,633 Time 739 , 774,304 Total deposits $ 8,322 , $ 8,444,420 Interest on deposits recorded in the consolidated statements of income consists of the following at December 31: (000’s omitted) 2018 2017 2016 Interest on interest checking $ 1,796 $ 1,032 $ 504 Interest on savings 858 841 863 Interest on money market 3,638 2,981 2,754 Interest on time 4,366 3,177 3,204 Total interest on deposits $ 10,658 $ 8,031 $ 7,325 The approximate maturities of time deposits at December 31, 2018 are as follows: (000’s omitted) All Accounts Accounts $250,000 or Greater 2019 $ 448,708 $ 40,960 2020 94,585 4,886 2021 123,021 20,100 2022 31,786 587 2023 41,223 3,087 Thereafter 217 0 Total $ 739 , $ 69 ,

BORROWINGS

BORROWINGS	12 Months Ended
	Dec. 31, 2018
BORROWINGS [Abstract]
BORROWINGS	NOTE H: BORROWINGS Outstanding borrowings at December 31 are as follows: (000’s omitted) 2018 2017 FHLB overnight advance $ 54 , $ 24,000 Subordinated debt held by unconsolidated subsidiary trusts, net of discount of $0 and $332, respectively 97 , 122,814 Securities sold under agreement to repurchase, short term 259 , 337,011 FHLB Long term advances 1 , 2,071 Total borrowings $ 413,682 $ 485,896 FHLB advances are collateralized by a blanket lien on the Company’s residential real estate loan portfolio and various investment securities. Borrowings at December 31, 2018 have contractual maturity dates as follows: (000’s omitted, except rate) Carrying Value Weighted-average Rate at December 31, 2018 January 2, 2019 $ 313,767 1.01 % July 3, 2023 575 2.25 % October 23, 2023 484 1.50 % October 1, 2025 315 1.50 % March 1, 2029 602 2.50 % December 15, 2034 20,619 4.74 % December 15, 2036 77,320 4.44 % Total $ 413,682 1.84 % The weighted-average interest rate on borrowings for the years ended December 31, 2018 and 2017 was 1.72% and 1.51%, respectively. As of December 31, 2018, the Company sponsors two business trusts, Community Capital Trust IV (“CCT IV”) and MBVT Statutory Trust I (“MBVT I”), of which 100% of the common stock is owned by the Company. The common stock of MBVT Statutory Trust I was acquired in the Merchants acquisition. The Company previously sponsored Community Statutory Trust III (“CST III”) until July 31, 2018 when the Company exercised its right to redeem all of the CST III debentures and associated preferred securities for a total of $25.2 million. The trusts were formed for the purpose of issuing company-obligated mandatorily redeemable preferred securities to third-party investors and investing the proceeds from the sale of such preferred securities solely in junior subordinated debt securities of the Company. The debentures held by each trust are the sole assets of such trust. Distributions on the preferred securities issued by each trust are payable quarterly at a rate per annum equal to the interest rate being earned by the trust on the debentures held by that trust and are recorded as interest expense in the consolidated financial statements. The preferred securities are subject to mandatory redemption, in whole or in part, upon repayment of the debentures. The Company has entered into agreements which, taken collectively, fully and unconditionally guarantee the preferred securities subject to the terms of each of the guarantees. The terms of the preferred securities of each trust are as follows: Trust Issuance Date Par Amount Interest Rate Maturity Date Call Price CCT IV 12/8/2006 $75.0 million 3 month LIBOR plus 1.65% (4.44%) 12/15/2036 Par MBVT I 12/15/2004 $20.6 million 3 month LIBOR plus 1.95% (4.74%) 12/15/2034 Par

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2018
INCOME TAXES [Abstract]
INCOME TAXES	NOTE I: INCOME TAXES The provision for income taxes for the years ended December 31 is as follows: (000’s omitted) 2018 2017 2016 Current: Federal $ 32,504 $ 31,152 $ 32,829 State and other 9,180 6,788 4,890 Deferred: Federal 2,122 (28,146 ) 11,444 State and other 541 (546 ) 1,622 Provision for income taxes $ 44,347 $ 9,248 $ 50,785 Components of the net deferred tax liability, included in other liabilities, as of December 31 are as follows: (000’s omitted) 2018 2017 Allowance for loan losses $ 12,131 $ 11,675 Employee benefits 4,479 4,216 Other, net 541 0 Deferred tax asset 17,151 15,891 Investment securities 14,451 22,690 Tax-deductible goodwill 39,540 39,154 Loan origination costs 6,851 6,109 Depreciation 3,098 2,372 Mortgage servicing rights 277 330 Pension 11,078 13,228 Other, net 0 542 Deferred tax liability 75,295 84,425 Net deferred tax liability $ (58,144 ) $ (68,534 ) The Company has determined that no valuation allowance is necessary as it is more likely than not that the gross deferred tax assets will be realized through future reversals of existing temporary differences and through future taxable income. A reconciliation of the differences between the federal statutory income tax rate and the effective tax rate for the years ended December 31 is shown in the following table: 2018 2017 2016 Federal statutory income tax rate 21.0 % 35.0 % 35.0 % Increase (reduction) in taxes resulting from: Tax-exempt interest (1.6 ) (3.8 ) (4.0 ) State income taxes, net of federal benefit 3.4 2.5 2.7 Stock-based compensation (0.9 ) (2.0 ) 0 Federal deferred tax revaluation adjustment 0 (23.7 ) 0 Federal tax credits (1.4 ) (1.5 ) 0 Other, net 0.3 (0.7 ) (0.9 ) Effective income tax rate 20.8 % 5.8 % 32.8 % A reconciliation of the unrecognized tax benefits for the years ended December 31 is shown in the following table: (000’s omitted) 2018 2017 2016 Unrecognized tax benefits at beginning of year $ 24 $ 92 $ 127 Changes related to: Lapse of statutes of limitations (24 ) (68 ) (35 ) Unrecognized tax benefits at end of year $ 0 $ 24 $ 92 As of December 31, 2018, there was no amount of unrecognized tax benefits that would impact the Company’s effective tax rate if recognized. It is reasonably possible that the amount of unrecognized tax benefits could change in the next twelve months as a result of various examinations and expiration of statutes of limitations on prior tax returns. The Company’s policy is to recognize interest and penalties related to unrecognized tax benefits as part of income taxes in the consolidated statement of income. The accrued interest related to tax positions was immaterial. The Company’s federal and state income tax returns are routinely subject to examination from various governmental taxing authorities. Such examinations may result in challenges to the tax return treatment applied by the Company to specific transactions. Management believes that the assumptions and judgment used to record tax-related assets or liabilities have been appropriate. Future examinations by taxing authorities of the Company’s federal or state tax returns could have a material impact on the Company’s results of operations. The Company’s federal income tax returns for years after 2014 may still be examined by the Internal Revenue Service. New York State income tax returns for years after 2014 may still be examined by the New York Department of Taxation and Finance. It is not possible to estimate, if and when those examinations may be completed. On December 22, 2017, H.R.1, referred to as the “Tax Cuts and Jobs Act,” was signed into law. Among other things, the Tax Cuts and Jobs Act lowered the corporate tax rate to 21% from the existing maximum rate of 35%, effective for tax years including or commencing January 1, 2018. ASC 740, Income Taxes

LIMITS ON DIVIDENDS AND OTHER R

LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES	12 Months Ended
	Dec. 31, 2018
LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES [Abstract]
LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES	NOTE J: LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES The Company’s ability to pay dividends to its shareholders is largely dependent on the Bank’s ability to pay dividends to the Company. In addition to the capital requirements discussed below, the circumstances under which the Bank may pay dividends are limited by federal statutes, regulations, and policies. For example, as a national bank, the Bank must obtain the approval of the Office of the Comptroller of the Currency (“OCC”) for payments of dividends if the total of all dividends declared in any calendar year would exceed the total of the Bank’s net profits, as defined by applicable regulations, for that year, combined with its retained net profits for the preceding two years. Furthermore, the Bank may not pay a dividend in an amount greater than its undivided profits then on hand after deducting its losses and bad debts, as defined by applicable regulations. At December 31, 2018, the Bank had approximately $101.2 million in undivided profits legally available for the payment of dividends. In addition, the Board of Governors of the Federal Reserve System (“FRB”) and the OCC are authorized to determine under certain circumstances that the payment of dividends would be an unsafe or unsound practice and to prohibit payment of such dividends. The FRB has indicated that banking organizations should generally pay dividends only out of current operating earnings. There are also statutory limits on the transfer of funds to the Company by its banking subsidiary, whether in the form of loans or other extensions of credit, investments or assets purchases. Such transfer by the Bank to the Company generally is limited in amount to 10% of the Bank’s capital and surplus, or 20% in the aggregate. Furthermore, such loans and extensions of credit are required to be collateralized in specific amounts.

BENEFIT PLANS

BENEFIT PLANS	12 Months Ended
	Dec. 31, 2018
BENEFIT PLANS [Abstract]
BENEFIT PLANS	NOTE K: BENEFIT PLANS Pension and post-retirement plans The Company provides a qualified defined benefit pension to eligible employees and retirees, other post-retirement health and life insurance benefits to certain retirees, an unfunded supplemental pension plan for certain key executives, and an unfunded stock balance plan for certain of its nonemployee directors. Using a measurement date of December 31, the following table shows the funded status of the Company’s plans reconciled with amounts reported in the Company’s consolidated statements of condition: Pension Benefits Post-retirement Benefits (000’s omitted) 2018 2017 2018 2017 Change in benefit obligation: Benefit obligation at the beginning of year $ 147,450 $ 127,084 $ 1,785 $ 1,806 Service cost 4,561 4,181 0 0 Interest cost 5,676 5,717 69 76 Plan amendment / acquisition 883 11,646 0 0 Participant contributions 0 0 479 467 Deferred actuarial (gain)/loss (4,177 ) 8,978 191 245 Benefits paid (10,182 ) (10,156 ) (867 ) (809 ) Benefit obligation at end of year 144,211 147,450 1,657 1,785 Change in plan assets: Fair value of plan assets at beginning of year 217,107 180,400 0 0 Actual return of plan assets (3,858 ) 22,954 0 0 Participant contributions 0 0 479 467 Employer contributions 605 9,839 388 342 Plan acquisition 0 14,070 0 0 Benefits paid (10,182 ) (10,156 ) (867 ) (809 ) Fair value of plan assets at end of year 203,672 217,107 0 0 Over/(Under) funded status at year end $ 59,461 $ 69,657 $ (1,657 ) $ (1,785 ) Amounts recognized in the consolidated statement of condition were: Other assets $ 72,659 $ 81,000 $ 0 $ 0 Other liabilities (13,198 ) (11,343 ) (1,657 ) (1,785 ) Amounts recognized in accumulated other comprehensive loss/(income) (“AOCI”) were: Net loss $ 39,410 $ 26,935 $ 592 $ 420 Net prior service cost (credit) 4,939 2,944 (1,444 ) (1,622 ) Pre-tax AOCI 44,349 29,879 (852 ) (1,202 ) Taxes (10,870 ) (7,340 ) 210 296 AOCI at year end $ 33,479 $ 22,539 $ (642 ) $ (906 ) The benefit obligation for the defined benefit pension plan was $131.0 million and $136.1 million as of December 31, 2018 and 2017, respectively, and the fair value of plan assets as of December 31, 2018 and 2017 was $203.7 million and $217.1 million, respectively. Effective May 12, 2017, the Merchants Bank Pension Plan was merged into the Community Bank System, Inc. Pension Plan and the combined plan was revalued resulting in an additional unamortized actuarial gain of approximately $1.9 million, due primarily to a gain on plan assets that was partially offset by a decrease in the discount rate from 4.50% to 4.40% as of the valuation date. The defined benefit pension plan was amended effective December 31, 2018 to transfer certain obligations from the Company’s non-qualified supplemental pension plan and restoration plan into the qualified defined benefit pension plan. The Company has unfunded supplemental pension plans for certain key active and retired executives. The projected benefit obligation for the unfunded supplemental pension plan for certain key executives was $13.2 million and $11.3 million for 2018 and 2017, respectively. The Company also has an unfunded stock balance plan for certain of its nonemployee directors. The projected benefit obligation for the unfunded stock balance plan was $0.1 million for 2018 and 2017. The plan was frozen effective December 31, 2009. Effective June 1, 2018, the Company adopted the Community Bank System, Inc. Restoration Plan (“Restoration Plan”). The Restoration Plan is a non-qualified deferred compensation plan for certain employees whose benefits under tax-qualified retirement plans are restricted by the Internal Revenue Code Section 401(a)(17) limitation on compensation. Adoption of the plan resulted in an unfunded initial projected benefit obligation of approximately $0.8 million. The Restoration Plan was amended effective December 31, 2018 to transfer certain obligations into the Company’s qualified defined benefit pension plan. The projected benefit obligation for the unfunded Restoration Plan is immaterial as of December 31, 2018. Effective December 31, 2009, the Company terminated its post-retirement medical program for current and future employees. Remaining plan participants will include only existing retirees as of December 31, 2010. This change was accounted for as a negative plan amendment and a $3.5 million, net of income taxes, benefit for prior service was recognized in AOCI in 2009. This negative plan amendment is being amortized over the expected benefit utilization period of remaining plan participants. Amounts recognized in accumulated other comprehensive income, net of tax, for the year ended December 31, are as follows: Pension Benefits Post-retirement Benefits (000’s omitted) 2018 2017 2018 2017 Prior service cost/(credit) $ 1,509 $ 424 $ 135 $ 111 Net (gain) loss 9,431 (851 ) 129 148 Total $ 10,940 $ (427 ) $ 264 $ 259 The estimated costs, net of tax, that will be amortized from accumulated other comprehensive (income) loss into net periodic (income) cost over the next fiscal year are as follows: (000’s omitted) Pension Benefits Post-retirement Benefits Prior service credit $ 64 $ (179 ) Net loss 2,376 36 Total $ 2,440 $ (143 ) The weighted-average assumptions used to determine the benefit obligations as of December 31 are as follows: Pension Benefits Post-retirement Benefits 2018 2017 2018 2017 Discount rate 4.50 % 4.00 % 4.45 % 4.00 % Expected return on plan assets 7.00 % 7.00 % N/A N/A Rate of compensation increase 3.50 % 3.50 % N/A N/A The net periodic benefit cost as of December 31 is as follows: Pension Benefits Post-retirement Benefits (000’s omitted) 2018 2017 2016 2018 2017 2016 Service cost $ 4,561 $ 4,181 $ 4,106 $ 0 $ 0 $ 0 Interest cost 5,676 5,717 5,624 69 76 82 Expected return on plan assets (14,820 ) (13,354 ) (11,842 ) 0 0 0 Plan amendment 13 0 20 0 0 0 Amortization of unrecognized net loss/(gain) 1,193 767 1,508 21 8 (5 ) Amortization of prior service cost (293 ) 55 43 (179 ) (179 ) (179 ) Net periodic (benefit) $ (3,670 ) $ (2,634 ) $ (541 ) $ (89 ) $ (95 ) $ (102 ) Prior service costs in which all or almost all of the plan’s participants are fully eligible for benefits under the plan are amortized on a straight-line basis over the expected future working years of all active plan participants. Unrecognized gains or losses are amortized using the “corridor approach”, which is the minimum amortization required. Under the corridor approach, the net gain or loss in excess of 10 percent of the greater of the projected benefit obligation or the market-related value of the assets is amortized on a straight-line basis over the expected future working years of all active plan participants. The weighted-average assumptions used to determine the net periodic pension cost for the years ended December 31 are as follows: Pension Benefits Post-retirement Benefits 2018 2017 2016 2018 2017 2016 Discount rate 4.00 % 4.40 % 4.70 % 4.00 % 4.40 % 4.70 % Expected return on plan assets 7.00 % 7.00 % 7.00 % N/A N/A N/A Rate of compensation increase 3.50 % 3.50 % 3.50 % N/A N/A N/A The amount of benefit payments that are expected to be paid over the next ten years are as follows: (000’s omitted) Pension Benefits Post-retirement Benefits 2019 $ 9,250 $ 175 2020 9,547 139 2021 10,142 136 2022 10,607 133 2023 11,092 130 2024-2028 59,372 598 The payments reflect future service and are based on various assumptions including retirement age and form of payment (lump-sum versus annuity). Actual results may differ from these estimates. The assumed discount rate is used to reflect the time value of future benefit obligations. The discount rate was determined based upon the yield on high-quality fixed income investments expected to be available during the period to maturity of the pension benefits. This rate is sensitive to changes in interest rates. A decrease in the discount rate would increase the Company’s obligation and future expense while an increase would have the opposite effect. The expected long-term rate of return was estimated by taking into consideration asset allocation, reviewing historical returns on the type of assets held and current economic factors. Based on the Company’s anticipation of future experience under the defined benefit pension plan, the mortality tables used to determine future benefit obligations under the plan were updated as of December 31, 2018 to the RP-2014 Mortality Table for employees and healthy annuitants, adjusted backward to 2006 with Scale MP-2014, and then adjusted for mortality improvements with the Scale MP-2017 mortality improvement scale on a generational basis. The appropriateness of the assumptions are reviewed annually. Plan Assets The investment objective for the defined benefit pension plan is to achieve an average annual total return over a five-year period equal to the assumed rate of return used in the actuarial calculations. At a minimum performance level, the portfolio should earn the return obtainable on high quality intermediate-term bonds. The Company’s perspective regarding portfolio assets combines both preservation of capital and moderate risk-taking. Asset allocation favors fixed income securities, with a target allocation of approximately 60% equity securities and 40% fixed income securities and money market funds. Due to the volatility in the market, the target allocation is not always desirable and asset allocations will fluctuate between acceptable ranges. Prohibited transactions include purchase of securities on margin, uncovered call options, and short sale transactions. The fair values of the Company’s defined benefit pension plan assets at December 31, 2018 by asset category are as follows: Asset category (000’s omitted) Quoted Prices in Active Markets for Identical Assets Level 1 Significant Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Total Cash equivalents $ 4,856 $ 0 $ 0 $ 4,856 Equity securities: U.S. large-cap 39,122 0 0 39,122 U.S mid/small cap 9,881 0 0 9,881 CBU stock 7,692 0 0 7,692 International 32,506 0 0 32,506 89,201 0 0 89,201 Fixed income securities: Government securities 64,417 11,370 0 75,787 Investment grade bonds 12,054 0 0 12,054 High yield (a) 6,712 0 0 6,712 83,183 11,370 0 94,553 Other investments (b) 14,267 66 0 14,333 Total (c) $ 191,507 $ 11,436 $ 0 $ 202,943 The fair values of the Company’s defined benefit pension plan assets at December 31, 2017 by asset category are as follows: Asset category (000’s omitted) Quoted Prices in Active Markets for Identical Assets Level 1 Significant Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Total Money Market Accounts $ 0 $ 10,381 $ 0 $ 10,381 Equity securities: U.S. large-cap 53,154 0 0 53,154 U.S mid/small cap 26,309 0 0 26,309 CBU stock 8,344 0 0 8,344 International 47,723 0 0 47,723 135,530 0 0 135,530 Fixed income securities: Government securities 13,929 9,686 0 23,615 Investment grade bonds 19,278 0 0 19,278 High yield (a) 16,297 0 0 16,297 49,504 9,686 0 59,190 Other investments (b) 11,302 73 0 11,375 Total (c) $ 196,336 $ 20,140 $ 0 $ 216,476 (a) This category is exchange-traded funds representing a diversified index of high yield corporate bonds. (b) This category is comprised of exchange-traded funds and mutual funds holding non-traditional investment classes including private equity funds and alternative exchange funds. (c) Excludes dividends and interest receivable totaling $0.7 million and $0.6 million at December 31, 2018 and 2017, respectively. The valuation techniques used to measure fair value for the items in the table above are as follows: · Money market funds - Managed portfolios, including commercial paper and other fixed income securities issued by U.S. and foreign corporations, asset-backed commercial paper, U.S. government securities, obligations of foreign governments and U.S. and foreign banks, which are valued at the closing price reported on the market on which the underlying securities are traded. · Equity securities and other investments – Mutual funds, equity securities and common stock of the Company which are valued at the quoted market price of shares held at year-end. · Fixed income securities - U.S. Treasuries, municipal bonds and notes, government sponsored entities, and corporate debt valued at the closing price reported on the active market on which the individual securities are traded or for municipal bonds and notes based on quoted prices for similar assets in the active market. The Company makes contributions to its funded qualified pension plan as required by government regulation or as deemed appropriate by management after considering the fair value of plan assets, expected return on such assets, and the value of the accumulated benefit obligation. The Company funds the payment of benefit obligations for the supplemental pension and post-retirement plans because such plans do not hold assets for investment. 401(k) Employee Stock Ownership Plan The Company has a 401(k) Employee Stock Ownership Plan in which employees can contribute from 1% to 90% of eligible compensation, with the first 3% being eligible for a 100% matching contribution in the form of Company common stock and the next 3% being eligible for a 50% matching contributions in the form of Company common stock. The expense recognized under this plan for the years ended December 31, 2018, 2017 and 2016 was $5.9 million, $5.3 million, and $4.3 million, respectively. Effective January 1, 2010, the defined benefit pension plan was modified to a new plan design that includes an interest credit contribution to be made to the 401(k) plan. The expense recognized for this interest credit contribution for the years ended December 31, 2018, 2017, and 2016 was $0.9 million, $0.8 million, and $0.7 million, respectively. The Company acquired The Merchants Bank 401(k) ESOP Plan with the Merchants acquisition and The Gordon B. Roberts 401(k) Plan with the GBR acquisition. Effective January 1, 2018, The Merchants Bank 401(k) ESOP Plan and The Gordon B. Roberts 401(k) Plan were merged into and became part of the Community Bank System, Inc. 401(k) Employee Stock Ownership Plan. Other Deferred Compensation Arrangements In addition to the supplemental pension plans for certain executives, the Company has nonqualified deferred compensation arrangements for several former directors, officers and key employees. All benefits provided under these plans are unfunded and payments to plan participants are made by the Company. At December 31, 2018 and 2017, the Company has recorded a liability of $2.8 million and $3.1 million, respectively. The expense recognized under these plans for the years ended December 31, 2018, 2017, and 2016 was approximately $0.08 million, $0.3 million, and $0.03 million, respectively. Deferred Compensation Plans for Directors Directors of the Company may defer all or a portion of their director fees under the Deferred Compensation Plan for Directors. Under this plan, there is a separate account for each participating director which is credited with the amount of shares that could have been purchased with the director’s fees as well as any dividends on such shares. On the distribution date, the director will receive common stock equal to the accumulated share balance in their account. As of December 31, 2018 and 2017, there were 151,977 and 150,110 shares credited to the participants’ accounts, for which a liability of $4.6 million and $4.2 million was accrued, respectively. The expense recognized under the plan for the years ended December 31, 2018, 2017 and 2016, was $0.2 million, $0.2 million, and $0.2 million, respectively. The Company acquired deferred compensation plans for certain non-employee directors and trustees of Merchants. Under the terms of these acquired deferred compensation plans,

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS	12 Months Ended
	Dec. 31, 2018
STOCK-BASED COMPENSATION PLANS [Abstract]
STOCK-BASED COMPENSATION PLANS	NOTE L: STOCK-BASED COMPENSATION PLANS The Company has a long-term incentive program for directors, officers and employees. Under this program, the Company initially authorized four million shares of Company common stock for the grant of incentive stock options, nonqualified stock options, restricted stock awards, and retroactive stock appreciation rights. The long-term incentive program was amended effective May 25, 2011, May 14, 2014 and May 17, 2017 to authorize an additional 900,000 shares, 1,000,000 shares and 1,000,000 shares of Company common stock, respectively, for the grant of incentive stock options, nonqualified stock options, restricted stock awards, and retroactive stock appreciation rights. As of December 31, 2018, the Company has authorization to grant up to approximately 1.5 million additional shares of Company common stock for these instruments. The nonqualified (offset) stock options in its Director’s Stock Balance Plan vest and become exercisable immediately and expire one year after the date the director retires or two years in the event of death. The remaining options have a ten-year term, and vest and become exercisable on a grant-by-grant basis, ranging from immediate vesting to ratably over a five-year period. Activity in this long-term incentive program is as follows: Stock Options Outstanding Weighted- average Exercise Price of Shares Outstanding at December 31, 2016 1,755,992 $ 30.85 Granted 197,943 57.02 Exercised (238,499 ) 25.72 Forfeited (7,140 ) 37.47 Outstanding at December 31, 2017 1,708,296 34.57 Granted 213,504 55.92 Exercised (268,004 ) 27.94 Forfeited (9,435 ) 45.54 Outstanding at December 31, 2018 1,644,361 $ 38.36 Exercisable at December 31, 2018 1,010,795 $ 32.66 The following table summarizes the information about stock options outstanding under the Company’s stock option plan at December 31, 2018: Options outstanding Options exercisable Range of Exercise Price Shares Weighted -average Exercise Price Weighted- average Remaining Life (years) Shares Weighted -average Exercise Price $ 0.00 – $18.00 10,978 $ 17.82 0.31 10,978 $ 17.82 $ 18.001 – $28.00 215,014 23.26 2.67 215,014 23.26 $ 28.001 – $29.00 142,691 28.78 3.22 142,691 28.78 $ 29.001 – $30.00 185,866 29.79 4.21 185,866 29.79 $ 30.001 – $40.00 686,103 37.09 6.34 391,658 37.06 $ 40.001 – $60.00 403,709 56.45 8.73 64,588 56.72 TOTAL 1,644,361 $ 38.36 5.90 1,010,795 $ 32.66 The weighted-average remaining contractual term of outstanding and exercisable stock options at December 31, 2018 is 5.90 years and 4.71 years, respectively. The aggregate intrinsic value of outstanding and exercisable stock options at December 31, 2018 is $32.8 million and $25.9 million, respectively. The Company recognized stock-based compensation expense related to non-qualified stock options of $2.6 million, $2.2 million and $2.2 million for the years ended December 31, 2018, 2017 and 2016, respectively. A related income tax benefit was recognized of $0.6 million, $0.8 million and $0.8 million for the 2018, 2017 and 2016 years, respectively. Compensation expense related to restricted stock vesting recognized in the income statement for 2018, 2017 and 2016 was approximately $3.2 million, $2.7 million and $2.4 million, respectively. Management estimated the fair value of options granted using the Black-Scholes option-pricing model. This model was originally developed to estimate the fair value of exchange-traded equity options, which (unlike employee stock options) have no vesting period or transferability restrictions. As a result, the Black-Scholes model is not necessarily a precise indicator of the value of an option, but it is commonly used for this purpose. The Black-Scholes model requires several assumptions, which management developed based on historical trends and current market observations. 2018 2017 2016 Weighted-average Fair Value of Options Granted $ 13.44 $ 12.78 $ 7.90 Assumptions: Weighted-average expected life (in years) 6.50 6.50 6.50 Future dividend yield 2.91 % 3.19 % 3.43 % Share price volatility 29.44 % 29.71 % 30.00 % Weighted-average risk-free interest rate 2.82 % 2.31 % 1.72 % Unrecognized stock-based compensation expense related to non-vested stock options totaled $4.7 million at December 31, 2018. The weighted-average period over which this unrecognized expense would be recognized is 3.3 years. The total fair value of stock options vested during 2018, 2017, and 2016 were $2.3 million, $2.2 million and $2.1 million, respectively. During the 12 months ended December 31, 2018 and 2017, proceeds from stock option exercises totaled $9.4 million and $7.7 million, respectively, and the related tax benefits from exercise were approximately $1.6 million and $2.3 million, respectively. During the twelve months ended December 31, 2018 and 2017, approximately 0.3 million and 0.2 million shares, respectively, were issued in connection with stock option exercises each year. The total intrinsic value of options exercised during 2018, 2017 and 2016 were $8.4 million, $7.6 million and $10.3 million, respectively. A summary of the status of the Company’s unvested restricted stock awards as of December 31, 2018, and changes during the twelve months ended December 31, 2018 and 2017, is presented below: Restricted Shares Weighted-average grant date fair value Unvested at December 31, 2016 253,830 $ 29.98 Awards 46,428 57.02 Forfeitures (4,863 ) 24.78 Vestings (64,522 ) 33.69 Unvested at December 31, 2017 230,873 34.06 Awards 50,133 55.92 Forfeitures (3,429 ) 34.95 Vestings (56,514 ) 39.40 Unvested at December 31, 2018 221,063 $ 37.72 Unrecognized stock-based compensation expense related to unvested restricted stock totaled $4.6 million at December 31, 2018, which will be recognized as expense over the next five years. The weighted-average period over which this unrecognized expense would be recognized is 3.2 years. The total fair value of restricted stock vested during 2018, 2017, and 2016 were $2.3 million, $2.2 million and $2.5 million, respectively.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2018
EARNINGS PER SHARE [Abstract]
EARNINGS PER SHARE	NOTE M: EARNINGS PER SHARE The two class method is used in the calculations of basic and diluted earnings per share. Under the two class method, earnings available to common shareholders for the period are allocated between common shareholders and participating securities according to dividends declared and participation rights in undistributed earnings. The Company has determined that all of its outstanding non-vested stock awards are participating securities as of December 31, 2018. Basic earnings per share are computed based on the weighted-average of the common shares outstanding for the period. Diluted earnings per share are based on the weighted-average of the shares outstanding and the assumed exercise of stock options during the year. The dilutive effect of options is calculated using the treasury stock method of accounting. The treasury stock method determines the number of common shares that would be outstanding if all the dilutive options (those where the average market price is greater than the exercise price) were exercised and the proceeds were used to repurchase common shares in the open market at the average market price for the applicable time period. There were approximately 0.4 million, 0.2 million and 0.3 million weighted-average anti-dilutive stock options outstanding at December 31, 2018, 2017 and 2016, respectively, which were not included in the computation below. The following is a reconciliation of basic to diluted earnings per share for the years ended December 31, 2018, 2017 and 2016. (000’s omitted, except per share data) 2018 2017 2016 Net income $ 168,641 $ 150,717 $ 103,812 Income attributable to unvested stock-based compensation awards (744 ) (597 ) (550 ) Income available to common shareholders $ 167,897 $ 15 0, 0 $ 103,262 Weighted-average common shares outstanding - basic 51 , 48 , 44,091 Basic earnings per share $ 3.28 $ 3 . $ 2.34 Net income $ 168,641 $ 150,717 $ 103,812 Income attributable to unvested stock-based compensation awards (744 ) (597 ) (550 ) Income available to common shareholders $ 167,897 $ 150,12 0 $ 103,262 Weighted-average common shares outstanding 51 , 48 , 44,091 Assumed exercise of stock options 583 627 394 Weighted-average common shares outstanding – diluted 51 , 49,470 44,485 Diluted earnings per share $ 3.24 $ 3.03 $ 2.32 Cash dividends declared per share $ 1.44 $ 1.32 $ 1.26 Stock Repurchase Program At its December 2017 meeting, the Company’s Board of Directors (the “Board”) approved a stock repurchase program authorizing the repurchase of up to 2.5 million shares of the Company’s common stock in accordance with securities laws and regulations, through December 31, 2018. At its December 2018 meeting, the Board approved a similar program for 2019, authorizing the repurchase of up to 2.5 million shares of the Company’s common stock through December 31, 2019. Any repurchased shares will be used for general corporate purposes, including those related to stock plan activities. The timing and extent of repurchases will depend on market conditions and other corporate considerations as determined at the Company’s discretion. There were no stock repurchases pursuant to the announced plans in 2018 or 2017.

COMMITMENTS, CONTINGENT LIABILI

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS	12 Months Ended
	Dec. 31, 2018
COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS [Abstract]
COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS	NOTE N: COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS The Company is a party to financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments consist primarily of commitments to extend credit and standby letters of credit. Commitments to extend credit are agreements to lend to customers, generally having fixed expiration dates or other termination clauses that may require payment of a fee. These commitments consist principally of unused commercial and consumer credit lines. Standby letters of credit generally are contingent upon the failure of the customer to perform according to the terms of an underlying contract with a third party. The credit risks associated with commitments to extend credit and standby letters of credit are essentially the same as that involved with extending loans to customers and are subject to the Company’s normal credit policies. Collateral may be obtained based on management’s assessment of the customer’s creditworthiness. The fair value of the standby letters of credit is immaterial for disclosure. The contract amounts of commitments and contingencies are as follows at December 31: (000’s omitted) 2018 2017 Commitments to extend credit $ 1,134 , $ 1,080,004 Standby letters of credit 33 , 23,782 Total $ 1,167 , $ 1,103,786 The Bank has unused lines of credit of $25.0 million at December 31, 2018. The Bank has unused borrowing capacity of approximately $1.62 billion through collateralized transactions with the FHLB and $23.5 million through collateralized transactions with the Federal Reserve. The Company is required to maintain a reserve balance, as established by the FRB. The required average total reserve for the 14-day maintenance period of December 20, 2018 through January 2, 2019 was with $76.6 million represented by cash on hand and the remaining $13.1 million was required to be on deposit with the Federal Reserve. The Company and its subsidiaries are subject in the normal course of business to various pending and threatened legal proceedings in which claims for monetary damages are asserted. As of December 31, 2018, management, after consultation with legal counsel, does not anticipate that the aggregate ultimate liability arising out of litigation pending or threatened against the Company or its subsidiaries will be material to the Company’s consolidated financial position. On at least a quarterly basis the Company assesses its liabilities and contingencies in connection with such legal proceedings. For those matters where it is probable that the Company will incur losses and the amounts of the losses can be reasonably estimated, the Company records an expense and corresponding liability in its consolidated financial statements. To the extent the pending or threatened litigation could result in exposure in excess of that liability, the amount of such excess is not currently estimable. The range of reasonably possible losses for matters where an exposure is not currently estimable or considered probable, beyond the existing recorded liabilities, is between $0 and $1 million in the aggregate. Although the Company does not believe that the outcome of pending litigation will be material to the Company’s consolidated financial position, it cannot rule out the possibility that such outcomes will be material to the consolidated results of operations for a particular reporting period in the future.

LEASES

LEASES	12 Months Ended
	Dec. 31, 2018
LEASES [Abstract]
LEASES	NOTE O: LEASES The Company leases buildings, office space, and equipment under agreements that expire in various years. Rental expense included in operating expenses amounted to $9.0 million, $7.3 million and $5.8 million in 2018, 2017 and 2016, respectively. The future minimum rental commitments as of December 31, 2018 for all non-cancelable operating leases are as follows: 2019 $ 8,452 2020 7,262 2021 5,673 2022 4,411 2023 2,621 Thereafter 10,390 Total $ 38,809

REGULATORY MATTERS

REGULATORY MATTERS	12 Months Ended
	Dec. 31, 2018
REGULATORY MATTERS [Abstract]
REGULATORY MATTERS	NOTE P: REGULATORY MATTERS The Company and the Bank are subject to various regulatory capital requirements administered by federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of the Company’s and the Bank’s assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The Company’s and the Bank’s capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. Management believes, as of December 31, 2018, that the Company and Bank meet all applicable capital adequacy requirements. Basel III Transitional rules became effective for the Company on January 1, 2015 with all of the requirements being phased in over a multi-year schedule, and fully phased in by January 1, 2019. Beginning in 2016, the Company and the Bank are required to maintain a “capital conservation buffer,” composed entirely of common equity Tier 1 capital, in addition to minimum risk-based capital ratios. The required capital conservation buffer is 1.875% for 2018 and 1.25% for 2017. As of December 31, 2018 and 2017, the amounts, ratios and requirements for the Company are presented below calculated under the Basel III Standardized Transitional Approach. As of December 31, 2018, the OCC categorized the Company and Bank as “well capitalized” under the regulatory framework for prompt corrective action. Actual For capital adequacy purposes For capital adequacy purposes plus Capital Conservation Buffer To be well-capitalized under prompt corrective action (000’s omitted) Amount Ratio Amount Ratio Amount Ratio Amount Ratio Community Bank System, Inc.: 2018 Tier 1 Leverage ratio $ 1,093,166 11.08 % $ 394,700 4.00 % $ 493,375 5.00 % Tier 1 risk-based capital 1,093,166 18.23 % 359,747 6.00 % $ 472,168 7.875 % 479,662 8.00 % Total risk-based capital 1,142,927 19.06 % 479,662 8.00 % 592,083 9.875 % 599,578 10.00 % Common equity tier 1 capital 998,111 16.65 % 269,810 4.50 % 382,231 6.375 % 389,726 6.50 % 2017 Tier 1 Leverage ratio $ 995,860 10.00 % $ 398,183 4.00 % $ 497,729 5.00 % Tier 1 risk-based capital 995,860 16.64 % 358,988 6.00 % $ 433,777 7.25 % 478,651 8.00 % Total risk-based capital 1,043,910 17.45 % 478,651 8.00 % 553,440 9.25 % 598,314 10.00 % Common equity tier 1 capital 876,685 14.65 % 269,241 4.50 % 344,030 5.75 % 388,904 6.50 % Community Bank, N.A.: 2018 Tier 1 Leverage ratio $ 912,995 9.32 % $ 391,953 4.00 % $ 489,941 5.00 % Tier 1 risk-based capital 912,995 15.35 % 356,973 6.00 % $ 468,527 7.875 % 475,964 8.00 % Total risk-based capital 962,756 16.18 % 475,964 8.00 % 587,518 9.875 % 594,955 10.00 % Common equity tier 1 capital 912,940 15.35 % 267,730 4.50 % 379,284 6.375 % 386,721 6.50 % 2017 Tier 1 Leverage ratio $ 859,538 8.71 % $ 394,981 4.00 % $ 493,726 5.00 % Tier 1 risk-based capital 859,538 14.50 % 355,641 6.00 % $ 429,733 7.25 % 474,188 8.00 % Total risk-based capital 907,588 15.31 % 474,188 8.00 % 548,280 9.25 % 592,736 10.00 % Common equity tier 1 capital 859,483 14.50 % 266,731 4.50 % 340,823 5.75 % 385,278 6.50 %

PARENT COMPANY STATEMENTS

PARENT COMPANY STATEMENTS	12 Months Ended
	Dec. 31, 2018
PARENT COMPANY STATEMENTS [Abstract]
PARENT COMPANY STATEMENTS	NOTE Q: PARENT COMPANY STATEMENTS The condensed statements of condition of the parent company, Community Bank System, Inc., at December 31 are as follows: (000’s omitted) 2018 2017 Assets: Cash and cash equivalents $ 116,133 $ 84,460 Investment securities 3,452 4,322 Investment in and advances to: Bank subsidiary 1,522,109 1,511,780 Non-bank subsidiaries 182,617 169,341 Other assets 8,957 9,150 Total assets $ 1,833,268 $ 1,779,053 Liabilities and shareholders’ equity: Accrued interest and other liabilities $ 21,546 $ 20,924 Borrowings 97,939 122,814 Shareholders’ equity 1,713,783 1,635,315 Total liabilities and shareholders’ equity $ 1,833,268 $ 1,779,053 The condensed statements of income of the parent company for the years ended December 31 is as follows: (000’s omitted) 2018 2017 2016 Revenues: Dividends from subsidiaries: Bank subsidiary $ 98,000 $ 91,000 $ 89,000 Non-bank subsidiaries 9,250 35,500 1,750 Interest and dividends on investments 161 133 102 Total revenues 107,411 126,633 90,852 Expenses: Interest on borrowings 4,677 3,904 2,949 Acquisition expenses 0 91 429 Loss on debt prepayment 318 0 0 Other expenses 131 26 11 Total expenses 5,126 4,021 3,389 Income before tax benefit and equity in undistributed net income of subsidiaries 102,285 122,612 87,463 Income tax benefit 1,330 1,930 866 Income before equity in undistributed net income of subsidiaries 103,615 124,542 88,329 Equity in undistributed net income of subsidiaries 65,026 26,175 15,483 Net income $ 168,641 $ 150,717 $ 103,812 Other comprehensive (loss), net of tax: Changes in other comprehensive (loss)/income related to pension and other post retirement obligations (11,204 ) 168 3,322 Changes in other comprehensive loss related to unrealized losses on available-for-sale securities (30,402 ) (11,065 ) (14,714 ) Other comprehensive loss (41,606 ) (10,897 ) (11,392 ) Comprehensive income $ 127,035 $ 139,820 $ 92,420 The statements of cash flows of the parent company for the years ended December 31 is as follows: (000’s omitted) 2018 2017 2016 Operating activities: Net income $ 168 , $ 150,717 $ 103,812 Adjustments to reconcile net income to net cash provided by operating activities Equity in undistributed net income of subsidiaries (65 , ) (26,175 ) (15,483 ) Net change in other assets and other liabilities (1,084 ) 1,870 (215 ) Net cash provided by operating activities 102,531 126,412 88,114 Investing activities: Proceeds from redemption of investment securities 776 0 0 Cash paid for acquisitions, net of cash acquired of $0, $150,534, and $0, respectively 0 (139,471 ) 0 Capital contributions to subsidiaries 0 (11,063 ) 0 Net cash provided by/(used in) investing activities 776 (150,534 ) 0 Financing activities: Repayment of borrowings (25,207 ) 0 0 Issuance of common stock 12 , 0 9,700 15,326 Purchase of treasury stock (298 ) (3,306 ) (3,470 ) Sale of treasury stock 12 , 10,060 8,888 Increase in deferred compensation arrangements 298 3,306 0 Cash dividends paid (71 , ) (62,305 ) (55,048 ) Net cash used in financing activities (71 , ) (42,545 ) (34,304 ) Change in cash and cash equivalents 31,673 (66,667 ) 53,81 0 Cash and cash equivalents at beginning of year 84,460 151,127 97,317 Cash and cash equivalents at end of year $ 116 , $ 84,460 $ 151,127 Supplemental disclosures of cash flow information: Cash paid for interest $ 4 , $ 3,826 $ 2,909 Supplemental disclosures of noncash financing activities Dividends declared and unpaid $ 19 , $ 17,460 $ 14,268 Capital contributions to subsidiaries 0 513,769 0 Common stock issued for acquisition 0 343,132 0

FAIR VALUE

FAIR VALUE	12 Months Ended
	Dec. 31, 2018
FAIR VALUE [Abstract]
FAIR VALUE	NOTE R: FAIR VALUE Accounting standards allow entities an irrevocable option to measure certain financial assets and financial liabilities at fair value. Unrealized gains and losses on items for which the fair value option has been elected are reported in earnings. The Company has elected to value mortgage loans held for sale at fair value in order to more closely match the gains and losses associated with loans held for sale with the gains and losses on forward sales contracts. Accordingly, the impact on the valuation will be recognized in the Company’s consolidated statement of income. All mortgage loans held for sale are current and in performing status. Accounting standards establish a framework for measuring fair value and require certain disclosures about such fair value instruments. It defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e. exit price). Inputs used to measure fair value are classified into the following hierarchy: · Level 1 – Quoted prices in active markets for identical assets or liabilities. · Level 2 – Quoted prices in active markets for similar assets or liabilities, or quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability. · Level 3 – Significant valuation assumptions not readily observable in a market. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The following tables set forth the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis. There were no transfers between any of the levels for the periods presented. December 31, 2018 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,896,931 $ 126,822 $ 0 $ 2,023,753 Obligations of state and political subdivisions 0 459,154 0 459,154 Government agency mortgage-backed securities 0 382,477 0 382,477 Corporate debt securities 0 2,546 0 2,546 Government agency collateralized mortgage obligations 0 68,119 0 68,119 Total available-for-sale investment securities 1,896,931 1,039,118 0 2,936,049 Equity securities 432 0 0 432 Mortgage loans held for sale 0 83 0 83 Interest rate swap agreements asset 0 793 0 793 Interest rate swap agreements liability 0 (742 ) 0 (742 ) Total $ 1,897,363 $ 1,039,252 $ 0 $ 2,936,615 December 31, 2017 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,909,290 $ 144,781 $ 0 $ 2,054,071 Obligations of state and political subdivisions 0 528,956 0 528,956 Government agency mortgage-backed securities 0 357,538 0 357,538 Corporate debt securities 0 2,623 0 2,623 Government agency collateralized mortgage obligations 0 87,374 0 87,374 Marketable equity securities 526 0 0 526 Total available-for-sale investment securities 1,909,816 1,121,272 0 3,031,088 Mortgage loans held for sale 0 461 0 461 Commitments to originate real estate loans for sale 0 0 89 89 Forward sales commitments 0 4 0 4 Interest rate swap agreements asset 0 1,064 0 1,064 Interest rate swap agreements liability 0 (904 ) 0 (904 ) Total $ 1,909,816 $ 1,121,897 $ 89 $ 3,031,802 The valuation techniques used to measure fair value for the items in the table above are as follows: · Available for sale investment securities – The fair value of available-for-sale investment securities is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using quoted market prices for similar securities or model-based valuation techniques. Level 1 securities include U.S. Treasury obligations and marketable equity securities that are traded by dealers or brokers in active over-the-counter markets. Level 2 securities include U.S. agency securities, mortgage-backed securities issued by government-sponsored entities, municipal securities and corporate debt securities that are valued by reference to prices for similar securities or through model-based techniques in which all significant inputs, such as reported trades, trade execution data, LIBOR swap yield curve, market prepayment speeds, credit information, market spreads, and security’s terms and conditions, are observable. See Note C for further disclosure of the fair value of investment securities. · Mortgage loans held for sale – Mortgage loans held for sale are carried at fair value, which is determined using quoted secondary-market prices of loans with similar characteristics and, as such, have been classified as a Level 2 valuation. The unpaid principal value of mortgage loans held for sale at December 31, 2018 is approximately $0.1 million. The unrealized gain on mortgage loans was recognized in other banking services revenues in the Consolidated Statement of Income for the year ended December 31, 2018 and was immaterial. · Forward sales commitments – The Company enters into forward sales commitments to sell certain residential real estate loans. Such commitments are considered to be derivative financial instruments and, therefore, are carried at estimated fair value in the other asset or other liability section of the consolidated statement of condition. The fair value of these forward sales commitments is primarily measured by obtaining pricing from certain government-sponsored entities and reflects the underlying price the entity would pay the Company for an immediate sale on these mortgages. As such, these instruments are classified as Level 2 in the fair value hierarchy. · Commitments to originate real estate loans for sale – The Company enters into various commitments to originate residential real estate loans for sale. Such commitments are considered to be derivative financial instruments and, therefore, are carried at estimated fair value in the other asset or other liability section of the consolidated statement of condition. The estimated fair value of these commitments is determined using quoted secondary market prices obtained from certain government-sponsored entities. Additionally, accounting guidance requires the expected net future cash flows related to the associated servicing of the loan to be included in the fair value measurement of the derivative. The expected net future cash flows are based on a valuation model that calculates the present value of estimated net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income. Such assumptions include estimates of the cost of servicing loans, appropriate discount rate and prepayment speeds. The determination of expected net cash flows is considered a significant unobservable input contributing to the Level 3 classification of commitments to originate real estate loans for sale. · Interest rate swap agreements – The interest rate swaps are reported at their fair value utilizing Level 2 inputs from third parties. The fair value of our interest rate swaps are determined using prices obtained from a third party advisor. The fair value measurement of the interest rate swap is determined by netting the discounted future fixed cash payments and the discounted expected variable cash receipts. The variable cash receipts are based on the expectation of future interest rates derived from observed market interest rate curves. The changes in Level 3 assets measured at fair value on a recurring basis are immaterial. Assets and liabilities measured on a non-recurring basis: December 31, 2018 December 31, 2017 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Impaired loans $ 0 $ 0 $ 1,102 $ 1,102 $ 0 $ 0 $ 0 $ 0 Other real estate owned 0 0 1,320 1,320 0 0 1,915 1,915 Total $ 0 $ 0 $ 2,422 $ 2,422 $ 0 $ 0 $ 1,915 $ 1,915 Loans are generally not recorded at fair value on a recurring basis. Periodically, the Company records nonrecurring adjustments to the carrying value of loans based on fair value measurements for partial charge-offs of the uncollectible portions of those loans. Nonrecurring adjustments also include certain impairment amounts for collateral-dependent loans calculated when establishing the allowance for credit losses. Such amounts are generally based on the fair value of the underlying collateral supporting the loan and, as a result, the carrying value of the loan less the calculated valuation amount does not necessarily represent the fair value of the loan. Real estate collateral is typically valued using independent appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace, adjusted for non-observable inputs. Thus, the resulting nonrecurring fair value measurements are generally classified as Level 3. Estimates of fair value used for other collateral supporting commercial loans generally are based on assumptions not observable in the marketplace and, therefore, such valuations classify as Level 3. Other real estate owned (“OREO”) is valued at the time the loan is foreclosed upon and the asset is transferred to OREO. The value is based primarily on third party appraisals, less estimated costs to sell. The appraisals are sometimes further discounted based on management’s historical knowledge, changes in market conditions from the time of valuation, and/or management’s expertise and knowledge of the customer and customer’s business. Such discounts are significant, ranging from 9% to 69% at December 31, 2018, and result in a Level 3 classification of the inputs for determining fair value. OREO is reviewed and evaluated on at least a quarterly basis for additional impairment and adjusted accordingly, based on the same factors identified above. The Company recovers the carrying value of OREO through the sale of the property. The ability to affect future sales prices is subject to market conditions and factors beyond the Company’s control and may impact the estimated fair value of a property. Originated mortgage servicing rights are recorded at their fair value at the time of sale of the underlying loan, and are amortized in proportion to and over the estimated period of net servicing income. The fair value of mortgage servicing rights is based on a valuation model incorporating inputs that market participants would use in estimating future net servicing income. Such inputs include estimates of the cost of servicing loans, appropriate discount rate, and prepayment speeds and are considered to be unobservable and contribute to the Level 3 classification of mortgage servicing rights. In accordance with GAAP, the Company must record impairment charges, on a nonrecurring basis, when the carrying value of a stratum exceeds its estimated fair value. Impairment is recognized through a valuation allowance. There is no valuation allowance at December 31, 2018 as the fair value of mortgage servicing rights of approximately $2.4 million exceeded the carrying value of approximately $1.1 million. The Company evaluates goodwill for impairment on an annual basis, or more often if events or circumstances indicate there may be impairment. The fair value of each reporting unit is compared to the carrying amount of that reporting unit in order to determine if impairment is indicated. If so, the implied fair value of the reporting unit’s goodwill is compared to its carrying amount and the impairment loss is measured by the excess of the carrying value of the goodwill over fair value of the goodwill. In such situations, the Company performs a discounted cash flow modeling technique that requires management to make estimates regarding the amount and timing of expected future cash flows of the assets and liabilities of the reporting unit that enable the Company to calculate the implied fair value of the goodwill. It also requires use of a discount rate that reflects the current return expectation of the market in relation to present risk-free interest rates, expected equity market premiums, peer volatility indicators and company-specific risk indicators. The Company did not recognize an impairment charge during 2018 or 2017. The significant unobservable inputs used in the determination of fair value of assets classified as Level 3 on a recurring or non-recurring basis as of December 31, 2018 are as follows: (000's omitted) Fair Value Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Impaired loans $ 1,102 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 35.4% (28.8 %) Other real estate owned 1,320 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 69 . . %) The significant unobservable inputs used in the determination of fair value of assets classified as Level 3 on a recurring or non-recurring basis as of December 31, 2017 are as follows: (000's omitted) Fair Value Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Other real estate owned $ 1,915 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 99.0% (38.5 %) Commitments to originate real estate loans for sale 89 Discounted cash flow Embedded servicing value 1 % The Company determines fair values based on quoted market values, where available, estimates of present values, or other valuation techniques. Those techniques are significantly affected by the assumptions used, including, but not limited to, the discount rate and estimates of future cash flows. In that regard, the derived fair value estimates cannot be substantiated by comparison to independent markets and, in many cases, may not be realized in immediate settlement of the instrument. Certain financial instruments and all nonfinancial instruments are excluded from fair value disclosure requirements. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company. The carrying amounts and estimated fair values of the Company’s other financial instruments that are not accounted for at fair value at December 31, 2018 and 2017 are as follows: December 31, 2018 December 31, 2017 (000's omitted) Carrying Value Fair Value Carrying Value Fair Value Financial assets: Net loans $ 6,231,837 $ 6,247,939 $ 6,209,174 $ 6,244,941 Financial liabilities: Deposits 8,322,371 8,308,765 8,444,420 8,431,481 Short-term borrowings 54,400 54,400 24,000 24,000 Securities sold under agreement to repurchase, short-term 259,367 259,367 337,011 337,011 Other long-term debt 1,976 1,921 2,071 2,021 Subordinated debt held by unconsolidated subsidiary trusts 97,939 97,939 122,814 122,814 The following is a further description of the principal valuation methods used by the Company to estimate the fair values of its financial instruments. Loans have been classified as a Level 3 valuation. Fair values for variable rate loans that reprice frequently are based on carrying values. Fair values for fixed rate loans are estimated using discounted cash flows and interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. Deposits have been classified as a Level 2 valuation. The fair value of demand deposits, interest-bearing checking deposits, savings accounts and money market deposits is the amount payable on demand at the reporting date. The fair value of time deposit obligations are based on current market rates for similar products. Borrowings and subordinated debt held by unconsolidated subsidiary trusts have been classified as a Level 2 valuation. The fair value of FHLB overnight advances and securities sold under agreement to repurchase, short-term, is the amount payable on demand at the reporting date. Fair values for long-term borrowings and subordinated debt held by unconsolidated subsidiary trusts are estimated using discounted cash flows and interest rates currently being offered on similar securities. The difference between the carrying values of long-term borrowings and subordinated debt held by unconsolidated subsidiary trusts, and their fair values, are not material as of the reporting dates. Other financial assets and liabilities – Cash and cash equivalents have been classified as a Level 1 valuation, while accrued interest receivable and accrued interest payable have been classified as a Level 2 valuation. The fair values of each approximate the respective carrying values because the instruments are payable on demand or have short-term maturities and present relatively low credit risk and interest rate risk.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2018
DERIVATIVE INSTRUMENTS [Abstract]
DERIVATIVE INSTRUMENTS	NOTE S: DERIVATIVE INSTRUMENTS The Company is party to derivative financial instruments in the normal course of its business to meet the financing needs of its customers and to manage its own exposure to fluctuations in interest rates. These financial instruments have been limited to interest rate swap agreements, commitments to originate real estate loans held for sale and forward sales commitments. The Company does not hold or issue derivative financial instruments for trading or other speculative purposes. The Company enters into forward sales commitments for the future delivery of residential mortgage loans, and interest rate lock commitments to fund loans at a specified interest rate. The forward sales commitments are utilized to reduce interest rate risk associated with interest rate lock commitments and loans held for sale. Changes in the estimated fair value of the forward sales commitments and interest rate lock commitments subsequent to inception are based on changes in the fair value of the underlying loan resulting from the fulfillment of the commitment and changes in the probability that the loan will fund within the terms of the commitment, which is affected primarily by changes in interest rates and the passage of time. At inception and during the life of the interest rate lock commitment, the Company includes the expected net future cash flows related to the associated servicing of the loan as part of the fair value measurement of the interest rate lock commitments. These derivatives are recorded at fair value, which were immaterial at December 31, 2018. The effect of the changes to these derivatives for the year then ended was also immaterial. The Company acquired interest rate swaps from the Merchants acquisition with notional amounts with certain commercial customers which totaled $37.0 million at December 31, 2018. In order to minimize the Company’s risk, these customer derivatives (pay floating/receive fixed swaps) have been offset with essentially matching interest rate swaps (pay fixed/receive floating swaps) with the Company’s counterparty totaling $37.0 million. The weighted average receive rate of these interest rate swaps was 4.34%, the weighted average pay rate was 3.84% and the weighted average maturity was 5.5 years. The fair values of $0.7 million and $0.7 million were reflected in other assets and other liabilities, respectively, in the accompanying consolidated statement of condition at December 31, 2018. Hedge accounting has not been applied for these derivatives. Since the terms of the swaps with our customer and the other financial institution offset each other, with the only difference being counterparty credit risk, changes in the fair value of the underlying derivative contracts are not materially different and do not significantly impact our results of operations. The Company also acquired interest rate swaps from the Merchants acquisition with notional amounts totaling $6.6 million at December 31, 2018 that were designated as fair value hedges of certain fixed rate loans with municipalities. At December 31, 2018, the weighted average receive rate of these interest rate swaps was 2.92%, the weighted average pay rate was 3.11% and the weighted average maturity was 14.5 years. The fair value of $0.1 million at December 31, 2018, was reflected as a reduction to loans and an increase to other assets. The ineffective portion of the interest swaps was immaterial and as such, amounts are not recognized in earnings. The Company assessed its counterparty risk at December 31, 2018 and determined any credit risk inherent in our derivative contracts was not material. Information about the fair value of derivative financial instruments can be found in Note R to these consolidated financial statements.

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES	12 Months Ended
	Dec. 31, 2018
VARIABLE INTEREST ENTITIES [Abstract]
VARIABLE INTEREST ENTITIES	NOTE T: VARIABLE INTEREST ENTITIES The Company’s wholly-owned subsidiaries, Community Capital Trust IV and MBVT Statutory Trust I, are VIEs for which the Company is not the primary beneficiary. Accordingly, the accounts of these entities are not included in the Company’s consolidated financial statements. See further information regarding Community Capital Trust IV and MBVT Statutory Trust I in Note H: Borrowings. In connection with the Company’s acquisition of Oneida Financial Corp, the Company acquired OPFC II which holds a 50% membership interest in 706 North Clinton, LLC (“706 North Clinton”), an entity formed for the purpose of acquiring and rehabilitating real property. The real property held by 706 North Clinton is principally occupied by subsidiaries of the Company. The Company analyzed the operating agreement and capital structure of 706 North Clinton and determined that it was the primary beneficiary and therefore should consolidate 706 North Clinton in its financial statements. This conclusion was based on the determination that the Company has a de facto agency relationship because of the financing arrangement between the other member of 706 North Clinton and the Bank which provides OPFC II with both the power to direct the activities of 706 North Clinton and the obligation to absorb any losses of 706 North Clinton. The carrying amount of the assets and liabilities of 706 North Clinton and the classification of these assets and liabilities in the Company’s consolidated statements of condition at December 31 is as follows: (000’s omitted) 2018 2017 Cash and cash equivalents $ 104 $ 74 Premises and equipment, net 6,109 6,266 Other assets 33 5 Total assets $ 6,246 $ 6,345 Total liabilities $ 0 $ 0 In addition to the assets and liabilities of 706 North Clinton, the minority interest in 706 North Clinton of $3.1 million at December 31, 2018 is included in the Company’s consolidated statement of condition. The creditors of 706 North Clinton do not have a claim on the general assets of the Company. The Company’s maximum loss exposure net of minority interest in 706 North Clinton is approximately $4.8 million as of December 31, 2018, including a $1.7 million loss exposure related to the financing agreement between the other member of 706 North Clinton and the Bank.

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2018
SEGMENT INFORMATION [Abstract]
SEGMENT INFORMATION	NOTE U: SEGMENT INFORMATION Operating segments are components of an enterprise, which are evaluated regularly by the “chief operating decision maker” in deciding how to allocate resources and assess performance. The Company’s chief operating decision maker is the President and Chief Executive Officer of the Company. The Company has identified Banking, Employee Benefit Services and All Other as its reportable operating business segments. CBNA operates the Banking segment that provides full-service banking to consumers, businesses, and governmental units in Upstate New York as well as Northeastern Pennsylvania, Vermont and Western Massachusetts. Employee Benefit Services, which includes operating subsidiaries of BPAS, BPAS-APS, BPAS Trust Company of Puerto Rico, NRS and HB&T, management services including trust services provided by the personal trust unit within the Bank, broker-dealer and investment advisory services provided by CISI and The Carta Group, and asset management provided by Nottingham, and (b) full-service insurance, risk management and employee benefit services provided by OneGroup. The accounting policies used in the disclosure of business segments are the same as those described in the summary of significant accounting policies (See Note A). Information about reportable segments and reconciliation of the information to the consolidated financial statements follows: (000’s omitted) Banking Employee Benefit Services All Other Eliminations Consolidated Total 2018 Net interest income $ 344,551 $ 376 $ 128 $ 0 $ 345,055 Provision for loan losses 10,837 0 0 0 10,837 Noninterest revenue 75,399 94,449 57,204 (2,993 ) 224,059 Amortization of intangible assets 6,429 8,015 3,711 0 18,155 Acquisition expenses (782 ) 7 6 0 (769 ) Other operating expenses 231,362 56,275 43,259 (2,993 ) 327,903 Income before income taxes $ 172,104 $ 30,528 $ 10,356 $ 0 $ 212,988 Assets $ 10,397,623 $ 207,460 $ 68,288 $ (66,076 ) $ 10,607,295 Goodwill $ 629,916 $ 83,275 $ 20,312 $ 0 $ 733,503 Core deposit intangibles & Other intangibles $ 18,596 $ 44,545 $ 10,705 $ 0 $ 73,846 2017 Net interest income $ 315,025 $ 396 $ 254 $ 0 $ 315,675 Provision for loan losses 10,984 0 0 0 10,984 Noninterest revenue 73,337 82,743 49,201 (2,858 ) 202,423 Amortization of intangible assets 5,296 8,578 3,067 0 16,941 Acquisition expenses 24,549 1,194 243 0 25,986 Other operating expenses 218,608 51,138 37,334 (2,858 ) 304,222 Income before income taxes $ 128,925 $ 22,229 $ 8,811 $ 0 $ 159,965 Assets $ 10,505,919 $ 203,369 $ 66,548 $ (29,638 ) $ 10,746,198 Goodwill $ 629,916 $ 84,449 $ 20,065 $ 0 $ 734,430 Core deposit intangibles & Other intangibles $ 25,025 $ 52,288 $ 13,345 $ 0 $ 90,658 2016 Net interest income $ 273,542 $ 162 $ 192 $ 0 $ 273,896 Provision for loan losses 8,076 0 0 0 8,076 Noninterest revenue 66,059 48,261 43,747 (2,442 ) 155,625 Amortization of intangible assets 2,682 420 2,377 0 5,479 Acquisition expenses 1,005 445 256 0 1,706 Other operating expenses 190,263 36,892 34,950 (2,442 ) 259,663 Income before income taxes $ 137,575 $ 10,666 $ 6,356 $ 0 $ 154,597 Assets $ 8,598,057 $ 38,742 $ 71,428 $ (41,790 ) $ 8,666,437 Goodwill $ 440,870 $ 8,019 $ 16,253 $ 0 $ 465,142 Core deposit intangibles & Other intangibles $ 7,107 $ 666 $ 7,929 $ 0 $ 15,702

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2018
SUBSEQUENT EVENTS [Abstract]
SUBSEQUENT EVENTS	NOTE V: SUBSEQUENT EVENTS Companies are required to evaluate events and transactions that occur after the balance sheet date but before the date the financial statements are issued, or available to be issued in the case of non-public entities. They must recognize in the financial statements the effect of all events or transactions that provide additional evidence of conditions that existed at the balance sheet date, including the estimates inherent in the financial preparation process. Entities do not recognize the impact of events or transactions that provide evidence about conditions that did not exist at the balance sheet date but arose after that date. On January 22, 2019, the Company announced that it had entered into a definitive agreement to acquire Kinderhook Bank Corp. (“Kinderhook”), parent company of The National Union Bank of Kinderhook headquartered in Kinderhook, New York, for approximately $93.4 million in cash. The acquisition will extend the Company’s footprint into the Capital District of Upstate New York. Upon the completion of the merger, the Bank will add 11 branch locations across a five county area in the Capital District of Upstate New York. The acquisition is expected to close during the third quarter of 2019, pending both customary regulatory and Kinderhook shareholder approval. The Company expects to incur certain one-time, transaction-related costs in 2019. On January 2, 2019, the Company, through its subsidiary, Community Investment Services, Inc. (“CISI”), completed its acquisition of certain assets of Wealth Resources Network, Inc. (“Wealth Resources”), a financial services business headquartered in Liverpool, New York. The Company paid $1.2 million in cash to acquire the assets of Wealth Resources and recorded a $1.2 million customer list intangible asset in conjunction with the acquisition.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2018
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Nature of Operations	Nature of Operations Community Bank System, Inc. (the “Company”) is a registered financial holding company which wholly-owns two significant consolidated subsidiaries: Community Bank, N.A. (the “Bank” or “CBNA”), and Benefit Plans Administrative Services, Inc. (“BPAS”). As of December 31, 2018, BPAS owns five subsidiaries: Benefit Plans Administrative Services, LLC (“BPA”), a provider of defined benefit contribution plan administration services; Northeast Retirement Services, LLC (“NRS”), a provider of institutional transfer agency, master recordkeeping services, fund administration, trust and retirement plan services; BPAS Actuarial & Pension Services, LLC (“BPAS-APS”), a provider of actuarial and benefit consulting services; BPAS Trust Company of Puerto Rico, a Puerto Rican trust company; and Hand Benefits & Trust Company (“HB&T”), a provider of collective investment fund administration and institutional trust services. NRS owns one subsidiary, Global Trust Company, Inc. (“GTC”), a non-depository trust company which provides fiduciary services for collective investment trusts and other products. HB&T owns one subsidiary, Hand Securities Inc. (“HSI”), an introducing broker-dealer. The Company also wholly-owns two unconsolidated subsidiary business trusts formed for the purpose of issuing mandatorily-redeemable preferred securities which are considered Tier I capital under regulatory capital adequacy guidelines (see Note P). As of December 31, 2018, the Bank operated 224 full service branches operating as Community Bank, N.A. throughout 35 counties of Upstate New York, six counties of Northeastern Pennsylvania, 12 counties of Vermont and one county of Western Massachusetts, offering a range of commercial and retail banking services. The Bank owns the following operating subsidiaries: The Carta Group, Inc. (“Carta Group”), CBNA Preferred Funding Corporation (“PFC”), CBNA Treasury Management Corporation (“TMC”), Community Investment Services, Inc. (“CISI”), NOTCH Investment Fund, LLC (“NOTCH”), Nottingham Advisors, Inc. (“Nottingham”), OneGroup NY, Inc. (“OneGroup”), and Oneida Preferred Funding II LLC (“OPFC II”). OneGroup is a full-service insurance agency offering personal and commercial property insurance and other risk management products and services. NOTCH, PFC and OPFC II primarily act as investors in residential and commercial real estate activities. TMC provides cash management, investment, and treasury services to the Bank. CISI and Carta Group provide broker-dealer and investment advisory services. Nottingham provides asset management services to individuals, corporations, corporate pension and profit sharing plans, and foundations.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Variable Interest Entities (“VIE”) are legal entities in which equity investors do not have the characteristics of a controlling financial interest or do not have sufficient equity at risk for the legal entities to finance its activities without additional subordinated financial support. VIEs may be required to be consolidated by a company if it is determined the company is the primary beneficiary of a VIE. The primary beneficiary of a VIE is the enterprise that has: (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance, and (2) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits of the VIE that could potentially be significant to the VIE. The Company’s VIE’s are described in more detail in Note T to the consolidated financial statements.
Critical Accounting Estimates in the Preparation of Financial Statements	Critical Accounting Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Critical accounting estimates include the allowance for loan losses, actuarial assumptions associated with the pension, post-retirement and other employee benefit plans, the provision for income taxes, investment valuation and other-than-temporary impairment, the carrying value of goodwill and other intangible assets, and acquired loan valuations.
Risk and Uncertainties	Risk and Uncertainties In the normal course of its business, the Company encounters economic and regulatory risks. There are three main components of economic risk: interest rate risk, credit risk and market risk. The Company is subject to interest rate risk to the degree that its interest-bearing liabilities mature or reprice at different speeds, or on different basis, from its interest-earning assets. The Company’s primary credit risk is the risk of default on the Company’s loan portfolio that results from the borrowers’ inability or unwillingness to make contractually required payments. Market risk reflects potential changes in the value of collateral underlying loans, the fair value of investment securities, and loans held for sale. The Company is subject to regulations of various governmental agencies. These regulations can change significantly from period to period. The Company also undergoes periodic examinations by the regulatory agencies which may subject it to further changes with respect to asset valuations, amounts of required loan loss allowances, and operating restrictions resulting from the regulators’ judgments based on information available to them at the time of their examinations.
Revenue Recognition	Revenue Recognition On January 1, 2018, the Company adopted ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities. In addition, certain noninterest income streams such as fees associated with mortgage servicing rights, financial guarantees, derivatives, and certain credit card fees are also not in scope of the newly adopted guidance. Topic 606 is applicable to the Company’s noninterest revenue streams including its deposit related fees, electronic payment interchange fees, merchant income, trust, asset management and other wealth management revenues, insurance commissions and benefit plan services income. However, the recognition of these revenue streams did not change significantly upon adoption of Topic 606. Noninterest revenue streams in-scope of Topic 606 are discussed below. Deposit Service Fees Deposit service fees consist of account activity fees, monthly service fees, check orders, debit and credit card income, ATM fees, Merchant services income and other revenues from processing wire transfers, bill pay service, cashier’s checks and foreign exchange. Debit and credit card income is primarily comprised of interchange fees earned at the time the Company’s debit and credit cards are processed through card payment networks such as Visa. ATM fees are primarily generated when a Company cardholder uses a non-Company ATM or a non-Company cardholder uses a Company ATM. Merchant services income mainly represents fees charged to merchants to process their debit and credit card transactions, in addition to account management fees. The Company’s performance obligation for deposit service fees is generally satisfied, and the related revenue recognized, when the services are rendered or the transaction has been completed. Payment for deposit service fees is typically received at the time it is assessed through a direct charge to customers’ accounts or on a monthly basis. Deposit service fees revenue primarily relates to the Company’s Banking operating segment. Other Banking Services Other banking services consists of other recurring revenue streams such as commissions from sales of credit life insurance, safe deposit box rental fees, mortgage banking income, bank owned life insurance income and other miscellaneous revenue streams. Commissions from the sale of credit life insurance are recognized at the time of sale of the policies. Safe deposit box rental fees are charged to the customer on an annual basis and recognized upon receipt of payment. The Company determined that since rentals and renewals occur fairly consistently over time, revenue is recognized on a basis consistent with the duration of the performance obligation. Mortgage banking income and bank owned life insurance income are not within the scope of Topic 606. Other banking services revenue primarily relates to the Company’s Banking operating segment. Employee Benefit Services Employee benefit services income consists of revenue received from retirement plan services, collective investment fund services, fund administration, transfer agency, consulting and actuarial services. The Company’s performance obligation that relates to plan services are satisfied over time and the resulting fees are recognized monthly or quarterly, based upon the market value of the assets under management and the applicable fee rate or on a time expended basis. Payment is generally received a few days after month end or quarter end. The Company does not earn performance-based incentives. Transactional services such as consulting services, mailings, or other ad hoc services are provided to existing trust and asset management customers. The Company’s performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e., as incurred). Payment is received shortly after services are rendered. Employee benefit services revenue primarily relates to the Company’s Employee Benefit Services operating segment. Insurance Services Insurance services primarily consists of commissions received on insurance product sales and consulting services. The Company acts in the capacity of a broker or agent between the Company’s customer and the insurance carrier. The Company’s performance obligation related to insurance sales for both property and casualty insurance and employee benefit plans is generally satisfied upon the later of the issuance or effective date of the policy. The Company’s performance obligation related to consulting services is considered transactional in nature and is generally satisfied when the services have been completed and related revenue recognized at a point in time. Payment is received at the time services are rendered. The Company earns performance based incentives, commonly known as contingency payments, which usually are based on certain criteria established by the insurance carrier such as premium volume, growth and insured loss ratios. Contingent payments are accrued for based upon management’s expectations for the year. Commission expense associated with sales of insurance products is expensed as incurred. Insurance services revenue primarily relates to the Company’s All Other operating segment. Wealth Management Services Wealth management services income is primarily comprised of fees earned from the management and administration of trusts and other customer assets. The Company generally has two types of performance obligations related to these services. The Company’s performance obligation that relates to advisory and administration services are satisfied over time and the resulting fees are recognized monthly, based upon the market value of the assets under management and the applicable fee rate. Payment is generally received soon after month end or quarter end through a direct charge to customers’ accounts. The Company does not earn performance-based incentives. Transactional services such as tax return preparation services, purchases and sales of investments and insurance products are also available to existing trust and asset management customers. The Company’s performance obligation for these transactional-based services is generally satisfied, and related revenue recognized, at a point in time (i.e. as incurred). Payment is generally received on a monthly basis. Wealth management services revenue primarily relates to the Company’s All Other operating segment. Contract Balances A contract asset balance occurs when an entity performs a service for a customer before the customer pays consideration (resulting in a contract receivable) or before payment is due (resulting in a contract asset). A contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment (or payment is due) from the customer. The Company’s noninterest revenue streams are largely based on transactional activity, or standard month-end revenue accruals such as asset management fees based on month-end market values. Consideration is often received immediately or shortly after the Company satisfies its performance obligation and revenue is recognized. The Company does not typically enter into long-term revenue contracts with customers, and therefore, does not experience significant contract balances. As of December 31, 2018, $26.4 million of accounts receivable, including $7.8 million of unbilled fee revenue, and $2.2 million of unearned revenue was recorded in the Consolidated Statements of Condition. As of December 31, 2017, $29.8 million of accounts receivable, including $6.5 million of unbilled fee revenue, and $3.9 million of unearned revenue was recorded in the Consolidated Statements of Condition. Contract Acquisition Costs In connection with the adoption of Topic 606, an entity is required to capitalize, and subsequently amortize into expense, certain incremental costs of obtaining a contract with a customer if these costs are expected to be recovered. The incremental costs of obtaining a contract are those costs that an entity incurs to obtain a contract with a customer that it would not have incurred if the contract had not been obtained (for example, sales commission). The Company utilizes the practical expedient method which allows entities to immediately expense contract acquisition costs when the asset that would have resulted from capitalizing these costs would have been amortized in one year or less. Upon adoption of Topic 606, the Company did not capitalize any contract acquisition costs.
Cash and Cash Equivalents	Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, and highly liquid investments with original maturities of less than 90 days. The carrying amounts reported in the consolidated statements of condition for cash and cash equivalents approximate those assets’ fair values. As of December 31, 2018 and 2017, cash and cash equivalents reported in the consolidated statements of condition included cash due from banks of $15.0 million and $36.0 million, respectively.
Investment Securities	Investment Securities The Company can classify its investments in debt securities as held-to-maturity, available-for-sale, or trading. Held-to-maturity securities are those for which the Company has the positive intent and ability to hold until maturity, and are reported at cost, which is adjusted for amortization of premiums and accretion of discounts. The Company did not use the held-to-maturity classification in 2017 or 2018. Available-for-sale debt securities are reported at fair value with net unrealized gains and losses reflected as a separate component of shareholders’ equity, net of applicable income taxes. None of the Company’s investment securities have been classified as trading securities at December 31, 2018. Equity securities with a readily determinable fair value are reported at fair value with net unrealized gains and losses recognized in the consolidated statement of income. Certain equity securities that do not have a readily determinable fair value are stated at cost, less impairment, adjusted for observable price changes in orderly transactions for identical or similar investments of the same issuer. These securities include restricted stock of the Federal Reserve Bank of New York (“Federal Reserve”) and the Federal Home Loan Bank of New York and the Federal Home Loan Bank of Boston (collectively referred to as “FHLB”), as well as other equity securities. Fair values for investment securities are based upon quoted market prices, where available. If quoted market prices are not available, fair values are based upon quoted market prices of comparable instruments, or a discounted cash flow model using market estimates of interest rates and volatility. The Company conducts an assessment of all securities in an unrealized loss An OTTI loss must be recognized for a debt security in an unrealized loss position if there is intent to sell the security or it is more likely than not the Company will be required to sell the security prior to recovery of its amortized cost basis. In this situation, the amount of loss recognized in income is equal to the difference between the fair value and the amortized cost basis of the security. Even if management does not have the intent, and it is not more likely than not that the Company will be required to sell the securities, an evaluation of the expected cash flows to be received is performed to determine if a credit loss has occurred. For debt securities, a critical component of the evaluation for OTTI is the identification of credit-impaired securities, where the Company does not expect to receive cash flows sufficient to recover the entire amortized cost basis of the security. In the event of a credit loss, only the amount of impairment associated with the credit loss would be recognized in income. The portion of the unrealized loss relating to other factors, such as liquidity conditions in the market or changes in market interest rates, is recorded in accumulated other comprehensive loss. The specific identification method is used in determining the realized gains and losses on sales of investment securities and OTTI charges. Premiums and discounts on securities are amortized and accreted, respectively, on the interest method basis over the period to maturity or estimated life of the related security. Purchases and sales of securities are recognized on a trade date basis.
Loans	Loans Loans are stated at unpaid principal balances, net of unearned income. Mortgage loans held for sale are carried at fair value and are included in loans held for sale on the consolidated statements of condition. Fair values for variable rate loans that reprice frequently are based on carrying values. Fair values for fixed rate loans are estimated using discounted cash flows and interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. The carrying amount of accrued interest approximates its fair value. Interest on loans is accrued and credited to operations based upon the principal amount outstanding. Nonrefundable loan fees and related direct costs are deferred and included in the loan balances where they are amortized over the life of the loan as an adjustment to loan yield using the effective yield method. Premiums and discounts on purchased loans are amortized using the effective yield method over the life of the loans.
Acquired Loans	Acquired loans Acquired loans are initially recorded at their acquisition date fair values. The carryover of allowance for loan losses is prohibited as any credit losses in the loans are included in the determination of the fair value of the loans at the acquisition date. Fair values for acquired loans are based on a discounted cash flow methodology that involves assumptions and judgments as to credit risk, prepayment risk, liquidity risk, default rates, loss severity, payment speeds, collateral values and discount rate. Acquired impaired loans Acquired loans that have evidence of deterioration in credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all contractually required payments are accounted for as impaired loans under ASC 310-30. The excess of undiscounted cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loans using the interest method. The difference between contractually required payments at acquisition and the undiscounted cash flows expected to be collected at acquisition is referred to as the non-accretable discount. The non-accretable discount represents estimated future credit losses and other contractually required payments that the Company does not expect to collect. Subsequent decreases in expected cash flows are recognized as impairments through a charge to the provision for loan losses resulting in an increase in the allowance for loan losses. Subsequent improvements in expected cash flows result in a recovery of previously recorded allowance for loan losses or a reversal of a corresponding amount of the non-accretable discount, which the Company then reclassifies as an accretable discount that is recognized into interest income over the remaining life of the loans using the interest method. Acquired loans that met the criteria for non-accrual of interest prior to acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if the Company can reasonably estimate the timing and amount of the expected cash flows on such loans and if the Company expects to fully collect the new carrying value of the loans. As such, the Company may no longer consider the loan to be non-accrual or non-performing and may accrue interest on these loans, including the impact of any accretable discount. Acquired non-impaired loans Acquired loans that do not meet the requirements under ASC 310-30 are considered acquired non-impaired loans. The difference between the acquisition date fair value and the outstanding balance represents the fair value adjustment for a loan and includes both credit and interest rate considerations. Fair value adjustments may be discounts (or premiums) to a loan’s cost basis and are accreted (or amortized) to net interest income (or expense) over the loan’s remaining life in accordance with ASC 310-20. Fair value adjustments for revolving loans are accreted (or amortized) using a straight line method. Term loans are accreted (or amortized) using the constant effective yield method. Subsequent to the purchase date, the methods used to estimate the allowance for loan losses for the acquired non-impaired loans is consistent with the policy described below. However, the Company compares the net realizable value of the loans to the carrying value, for loans collectively evaluated for impairment. The carrying value represents the net of the loan’s unpaid principal balance and the remaining purchase discount (or premium) that has yet to be accreted (or amortized) into interest income (or interest expense). When the carrying value exceeds the net realizable value, an allowance for loan losses is recognized.
Impaired and Other Nonaccrual Loans	Impaired and Other Nonaccrual Loans The Company places a loan on nonaccrual status when the loan becomes 90 days past due (or sooner, if management concludes collection is doubtful), except when, in the opinion of management, it is well-collateralized and in the process of collection. A loan may be placed on nonaccrual status earlier than ninety days past due if there is deterioration in the financial position of the borrower or if other conditions of the loan so warrant. When a loan is placed on nonaccrual status, uncollected accrued interest is reversed against interest income and the amortization of nonrefundable loan fees and related direct costs is discontinued. Interest income during the period the loan is on nonaccrual status is recorded on a cash basis after recovery of principal is reasonably assured. Nonaccrual loans are returned to accrual status when management determines that the borrower’s performance has improved and that both principal and interest are collectible. This generally requires a sustained period of timely principal and interest payments and a well-documented credit evaluation of the borrower’s financial condition. A loan is considered modified in a troubled debt restructuring (“TDR”) when, due to a borrower’s financial difficulties, the Company makes a concession(s) to the borrower that it would not otherwise consider. These modifications may include, among others, an extension for the term of the loan, or granting a period when interest–only payments can be made with the principal payments and interest caught up over the remaining term of the loan or at maturity. Generally, a nonaccrual loan that has been modified in a TDR remains on nonaccrual status for a period of 12 months to demonstrate that the borrower is able to meet the terms of the modified loan. If the borrower’s ability to meet the revised payment schedule is uncertain, the loan remains on nonaccrual status. Regulatory guidance issued by the OCC requires certain loans that have been discharged in Chapter 7 bankruptcy to be reported as TDRs. In accordance with this guidance, loans that have been discharged in Chapter 7 bankruptcy but not reaffirmed by the borrower are classified as TDRs, irrespective of payment history or delinquency status, even if the repayment terms for the loan have not been otherwise modified and the Company’s lien position against the underlying collateral remains unchanged. Pursuant to that guidance, the Company records a charge-off equal to any portion of the carrying value that exceeds the net realizable value of the collateral. Commercial loans greater than $0.5 million are evaluated individually for impairment. A loan is considered impaired, based on current information and events, if it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. The measurement of impaired loans is generally based upon the present value of expected future cash flows or the fair value of the collateral, if the loan is collateral-dependent. The Company’s charge-off policy by loan type is as follows: · Business lending loans are generally charged-off to the extent outstanding principal exceeds the fair value of estimated proceeds from collection efforts, including liquidation of collateral. The charge-off is recognized when the loss becomes reasonably quantifiable. · Consumer installment loans are generally charged-off to the extent outstanding principal exceeds the fair value of collateral, and are recognized by the end of the month in which the loan becomes 90 days past due. · Consumer mortgage and home equity loans are generally charged-off to the extent outstanding principal exceeds the fair value of the property, less estimated costs to sell, and are recognized when the loan becomes 180 days past due.
Allowance for Loan Losses	Allowance for Loan Losses Management continually evaluates the credit quality of the Company’s loan portfolio, and performs a formal review of the adequacy of the allowance for loan losses on a quarterly basis. The allowance reflects management’s best estimate of probable losses inherent in the loan portfolio. Determination of the allowance is subjective in nature and requires significant estimates. The Company’s allowance methodology consists of two broad components - general and specific loan loss allocations. The general loan loss allocation is composed of two calculations that are computed on five main loan segments: business lending, consumer direct, consumer indirect, home equity and consumer mortgage. The first calculation is quantitative and determines an allowance level based on the latest 36 months of historical net charge-off data for each loan class (commercial loans exclude balances with specific loan loss allocations). The second calculation is qualitative and takes into consideration eight qualitative environmental factors: levels and trends in delinquencies and impaired loans; levels of and trends in charge-offs and recoveries; trends in volume and terms of loans; effects of any changes in risk selection and underwriting standards, and other changes in lending policies, procedures, and practices; experience, ability, and depth of lending management and other relevant staff; national and local economic trends and conditions; industry conditions; and effects of changes in credit concentrations. A component of the qualitative calculation is the unallocated allowance for loan loss. The qualitative and quantitative calculations are added together to determine the general loan loss allocation. The specific loan loss allocation relates to individual commercial loans that are both greater than $0.5 million and in a nonaccruing status with respect to interest. Specific loan losses are based on discounted estimated cash flows, including any cash flows resulting from the conversion of collateral or collateral shortfalls. The allowance levels computed from the specific and general loan loss allocation methods are combined with unallocated allowances and allowances needed for acquired loans to derive the total required allowance for loan losses to be reflected on the Consolidated Statement of Condition. Loan losses are charged off against the allowance, while recoveries of amounts previously charged off are credited to the allowance. A provision for loan losses is charged to operations based on management’s periodic evaluation of factors previously mentioned.
Intangible Assets	Intangible Assets Intangible assets include core deposit intangibles, customer relationship intangibles and goodwill arising from acquisitions. Core deposit intangibles and customer relationship intangibles are amortized on either an accelerated or straight-line basis over periods ranging from seven to 20 years. The initial and ongoing carrying value of goodwill and other intangible assets is based upon discounted cash flow modeling techniques that require management to make estimates regarding the amount and timing of expected future cash flows. It also requires use of a discount rate that reflects the current return requirements of the market in relation to present risk-free interest rates, required equity market premiums, peer volatility indicators, and company-specific risk indicators. The Company evaluates goodwill for impairment on an annual basis, or more often if events or circumstances indicate there may be impairment. The implied fair value of a reporting unit’s goodwill is compared to its carrying amount and the impairment loss is measured by the excess of the carrying value over fair value. The fair value of each reporting unit is compared to the carrying amount of that reporting unit in order to determine if impairment is indicated.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation. Computer software costs that are capitalized only include external direct costs of obtaining and installing the software. The Company has not developed any internal use software. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. Useful lives range from three to 10 years for equipment; three to seven years for software and hardware; and 10 to 40 years for building and building improvements. Land improvements are depreciated over 20 years and leasehold improvements are amortized over the shorter of the term of the respective lease plus any optional renewal periods that are reasonably assured or life of the asset. Maintenance and repairs are charged to expense as incurred.
Other Real Estate	Other Real Estate Other real estate owned is comprised of properties acquired through foreclosure, or by deed in lieu of foreclosure. These assets are carried at fair value less estimated costs of disposal. At foreclosure, if the fair value, less estimated costs to sell, of the real estate acquired is less than the Company’s recorded investment in the related loan, a write-down is recognized through a charge to the allowance for loan losses. Any subsequent reduction in value is recognized by a charge to income. Operating costs associated with the properties are charged to expense as incurred. At December 31, 2018 and 2017, other real estate totaled $1.3 million and $1.9 million, respectively, and is included in other assets.
Mortgage Servicing Rights	Mortgage Servicing Rights Originated mortgage servicing rights are recorded at their fair value at the time of sale of the underlying loan, and are amortized in proportion to and over the period of estimated net servicing income or loss. The Company uses a valuation model that calculates the present value of future cash flows to determine the fair value of servicing rights. In using this valuation method, the Company incorporates assumptions that market participants would use in estimating future net servicing income, which includes estimates of the servicing cost per loan, the discount rate, and prepayment speeds. The carrying value of the originated mortgage servicing rights is included in other assets and is evaluated quarterly for impairment using these same market assumptions. The amount of impairment recognized is the amount by which the carrying value of the capitalized servicing rights for a stratum exceeds estimated fair value. Impairment is recognized through a valuation allowance.
Treasury Stock	Treasury Stock Repurchases of shares of the Company’s common stock are recorded at cost as a reduction of shareholders’ equity. Reissuance of shares of treasury stock is recorded at average cost.
Income Taxes	Income Taxes The Company and its subsidiaries file a consolidated federal income tax return. Provisions for income taxes are based on taxes currently payable or refundable as well as deferred taxes that are based on temporary differences between the tax basis of assets and liabilities and their reported amounts in the consolidated financial statements. Deferred tax assets and liabilities are reported in the consolidated financial statements at currently enacted income tax rates applicable to the period in which the deferred tax assets and liabilities are expected to be realized or settled. Benefits from tax positions should be recognized in the financial statements only when it is more likely than not that the tax position will be sustained upon examination by the appropriate taxing authority having full knowledge of all relevant information. A tax position meeting the more-likely-than-not recognition threshold should be measured at the largest amount of benefit for which the likelihood of realization upon ultimate settlement exceeds 50 percent. Should tax laws change or the taxing authorities determine that management’s assumptions were inappropriate, an adjustment may be required which could have a material effect on the Company’s results of operations.
Investments in Real Estate Limited Partnerships	Investments in Real Estate Limited Partnerships The Company has investments in various real estate limited partnerships that acquire, develop, own and operate low and moderate-income housing. The Company’s ownership interest in these limited partnerships ranges from 5.00% to 99.99% as of December 31, 2018. These investments are made directly in Low Income Housing Tax Credit, or LIHTC, partnerships formed by third parties. As a limited partner in these operating partnerships, the Company receives tax credits and tax deductions for losses incurred by the underlying properties. The Company accounts for its ownership interest in LIHTC partnerships in accordance with Accounting Standards Update (“ASU”) 2014-01, Investments – Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects
Repurchase Agreements	Repurchase Agreements The Company sells certain securities under agreements to repurchase. These agreements are treated as collateralized financing transactions. These secured borrowings are reflected as liabilities in the accompanying consolidated statements of condition and are recorded at the amount of cash received in connection with the transaction. Short-term securities sold under agreements to repurchase generally mature within one day from the transaction date. Securities, generally U.S. government and federal agency securities, pledged as collateral under these financing arrangements can be repledged by the secured party. Additional collateral may be required based on the fair value of the underlying securities.
Retirement Benefits	Retirement Benefits The Company provides defined benefit pension benefits to eligible employees and post-retirement health and life insurance benefits to certain eligible retirees. The Company also provides deferred compensation and supplemental executive retirement plans for selected current and former employees, officers, and directors. Expense under these plans is charged to current operations and consists of several components of net periodic benefit cost based on various actuarial assumptions regarding future experience under the plans, including discount rate, rate of future compensation increases and expected return on plan assets.
Derivative Financial Instruments and Hedging Activities	Derivative Financial Instruments and Hedging Activities The Company accounts for derivative financial instruments at fair value. If certain conditions are met, a derivative may be specifically designated as (1) a hedge of the exposure to changes in the fair value of a recognized asset or liability or an unrecognized firm commitment (“fair value hedge”), (2) a hedge of the exposure to variable cash flows of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (“cash flow hedge”), or (3) an instrument with no hedging designation (“stand-alone derivative”). For a fair value hedge, the gain or loss on the derivative, as well as the offsetting loss or gain on the hedged item, are recognized in current earnings as fair values change. For a cash flow hedge, the gain or loss on the derivative is reported in other comprehensive income and is reclassified into earnings in the same periods during which the hedged transaction affects earnings. For both types of hedges, changes in the fair value of derivatives that are not highly effective in hedging the changes in fair value or expected cash flows of the hedged item are recognized immediately in current earnings. Changes in the fair value of derivatives that do not qualify for hedge accounting are reported currently in earnings, as noninterest income. Net cash settlements on derivatives that qualify for hedge accounting are recorded in interest income or interest expense, based on the item being hedged. Net cash settlements on derivatives that do not qualify for hedge accounting are reported in noninterest income. Cash flows on hedges are classified in the consolidated statement of cash flow statement the same as the cash flows of the items being hedged. The Company formally documents the relationship between derivatives and hedged items, as well as the risk-management objective and strategy for undertaking hedge transactions at the inception of the hedging relationship. This documentation includes linking the fair value or cash flow hedges to specific assets and liabilities on the statement of condition or to specific commitments or forecasted transactions. The Company also formally assesses, both at the hedge’s inception and on an ongoing basis, whether the derivative instruments that are used are highly effective in offsetting changes in fair values or cash flows of the hedged items. When hedge accounting is discontinued, subsequent changes in fair value of the derivative are recorded in noninterest income. When a fair value hedge is discontinued, the hedged asset or liability is no longer adjusted for changes in fair value and the existing basis adjustment is amortized or accreted over the remaining life of the asset or liability. When a cash flow hedge is discontinued, but the hedged cash flows or forecasted transactions are still expected to occur, gains or losses that were accumulated in other comprehensive income are amortized into earnings over the same periods which the hedged transactions will affect earnings.
Assets Under Management or Administration	Assets Under Management or Administration Assets held in fiduciary or agency capacities for customers are not included in the accompanying consolidated statements of condition as they are not assets of the Company. All fees associated with providing asset management services are recorded on an accrual basis of accounting and are included in noninterest income.
Advertising	Advertising Advertising costs amounting to approximately $5.1 million, $5.7 million and $3.9 million for the years ending December 31, 2018, 2017 and 2016, respectively, are nondirect response in nature and expensed as incurred.
Bank Owned Life Insurance	Bank Owned Life Insurance The Company owns life insurance policies on certain current and former employees and directors where the Bank is the beneficiary. Bank owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value (“CSV”) adjusted for other charges or other amounts due that are probable at settlement. Increases in the CSV of the policies, as well as the death benefits received, net of any CSV, are recorded in noninterest income, and are not subject to income taxes.
Earnings Per Share	Earnings Per Share Using the two-class method, basic earnings per common share is computed based upon net income available to common shareholders divided by the weighted average number of common shares outstanding during each period, which excludes the outstanding unvested restricted stock. Diluted earnings per share is computed using the weighted average number of common shares determined for the basic earnings per common share computation plus the dilutive effect of stock options using the treasury stock method. Stock options where the exercise price is greater than the average market price of common shares were not included in the computation of earnings per diluted share as they would have been anti-dilutive. Shares held in rabbi trusts related to deferred compensation plans are considered outstanding for purposes of computing earnings per share.
Stock-based Compensation	Stock-based Compensation Companies are required to measure and record compensation expense for stock options and other share-based payments on the instruments’ fair value on the date of grant. Stock-based compensation expense is recognized ratably over the requisite service period for all awards (see Note L).
Fair Values of Financial Instruments	Fair Values of Financial Instruments The Company determines fair values based on quoted market values where available or on estimates using present values or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. In that regard, the derived fair value estimates cannot be substantiated by comparison to independent markets and, in many cases, could not be realized in immediate settlement of the instrument. Certain financial instruments and all nonfinancial instruments are excluded from this disclosure requirement. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company. The fair values of investment securities, loans, deposits, and borrowings have been disclosed in Note R.
Reclassifications	Reclassifications Certain reclassifications have been made to prior years’ balances to conform to the current year presentation.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. The Company adopted this guidance on January 1, 2018. The impact of the adoption of this guidance resulted in the reclassification of $0.2 million of other comprehensive income to retained earnings. See the Consolidated Statements of Comprehensive Income and Consolidated Statement of Changes in Shareholders’ Equity. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230) In March 2017, the FASB issued ASU No. 2017-07, Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.
New Accounting Pronouncements	New Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Topic 840, Leases In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326) In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other (Topic 350) In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2018
ACQUISITIONS [Abstract]
Estimated Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair value of the assets acquired and liabilities assumed after considering the measurement period adjustments described above: 2018 2017 2016 (000s omitted) Other (1) NRS Merchants Other (2) Total WJL Consideration paid : Cash $ 1,753 $ 70,073 $ 82,898 $ 6,775 $ 159,746 $ 575 Community Bank System, Inc. common stock 0 78,483 262,254 2,395 343,132 0 Total net consideration paid $ 1,753 148,556 345,152 9,170 502,878 575 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 16 11,063 40,730 339 52,132 0 Investment securities 0 20,294 370,648 0 390,942 0 Loans 0 0 1,488,157 0 1,488,157 0 Premises and equipment 10 411 16,608 27 17,046 0 Accrued interest receivable 0 72 4,773 0 4,845 0 Other assets 105 8,088 51,585 583 60,256 0 Core deposit intangibles 0 0 23,214 0 23,214 0 Other intangibles 1,343 60,200 2,857 5,626 68,683 288 Deposits 0 0 (1,448,406 ) 0 (1,448,406 ) 0 Other liabilities (31 ) (26,828 ) (11,750 ) (1,155 ) (39,733 ) 0 Short-term advances 0 0 (80,000 ) 0 (80,000 ) 0 Securities sold under agreement to repurchase, short-term 0 0 (278,076 ) 0 (278,076 ) 0 Long-term debt 0 0 (3,615 ) 0 (3,615 ) 0 Subordinated debt held by unconsolidated subsidiary trusts 0 0 (20,619 ) 0 (20,619 ) 0 Total identifiable assets, net 1,443 73,300 156,106 5,420 234,826 288 Goodwill $ 310 $ 75,256 $ 189,046 $ 3,750 $ 268,052 $ 287 (1) (2) Includes amounts related to the BAS, Dryfoos, NECM and GBR acquisitions.
Loans Acquired	The following is a summary of the loans acquired from Merchants at the date of acquisition: Acquired Acquired Total Impaired Non-impaired Acquired (000s omitted) Loans Loans Loans Contractually required principal and interest at acquisition $ 15,454 $ 1,872,574 $ 1,888,028 Contractual cash flows not expected to be collected (5,385 ) (14,753 ) (20,138 ) Expected cash flows at acquisition 10,069 1,857,821 1,867,890 Interest component of expected cash flows (793 ) (378,940 ) (379,733 ) Fair value of acquired loans $ 9,276 $ 1,478,881 $ 1,488,157
Pro Forma Financial Information	The pro forma information set forth below reflects the historical results of Merchants and NRS combined with the Company’s consolidated statement of income with adjustments related to (a) certain purchase accounting fair value adjustments and (b) amortization of customer lists and core deposit intangibles. Acquisition expenses related to the Merchants and NRS transactions totaling $25.7 million for the year ended December 31, 2017 were included in the pro forma information as if they were incurred in 2016. Pro Forma (Unaudited) Year Ended December 31, (000’s omitted) 2017 2016 Total revenue, net of interest expense $ 546,977 $ 536,183 Net income 176,257 109,186

INVESTMENT SECURITIES (Tables)

INVESTMENT SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2018
INVESTMENT SECURITIES [Abstract]
Amortized Cost and Estimated Fair Value of Investment Securities	The amortized cost and estimated fair value of investment securities as of December 31 are as follows: 2018 2017 (000’s omitted) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Available-for-Sale Portfolio: U.S. Treasury and agency securities $ 2,036 , $ 2,190 $ 14,911 $ 2,023 , $ 2,043,023 $ 15,886 $ 4,838 $ 2,054,071 Obligations of state and political subdivisions 453 , 6 , 1,049 459 , 514,949 14,064 57 528,956 Government agency mortgage-backed securities 390 , 1,526 9,283 382 , 358,180 3,121 3,763 357,538 Corporate debt securities 2,588 0 42 2,546 2,648 0 25 2,623 Government agency collateralized mortgage obligations 69 , 60 1,283 68 , 88,097 155 878 87,374 Marketable equity securities 0 0 0 0 251 275 0 526 Total available-for-sale portfolio $ 2,952,278 $ 10 , $ 26 , $ 2,936,049 $ 3,007,148 $ 33,501 $ 9,561 $ 3,031,088 Equity and other Securities: Equity securities, at fair value $ 251 $ 200 $ 19 $ 432 $ 0 $ 0 $ 0 $ 0 Federal Home Loan Bank common stock 8,768 0 0 8,768 9,896 0 0 9,896 Federal Reserve Bank common stock 30,690 0 0 30,690 30,690 0 0 30,690 Certificates of deposit 0 0 0 0 3,865 0 0 3,865 Other equity securities, at adjusted cost 4 , 750 0 5,719 5,840 0 0 5,840 Total equity and other securities $ 44 , $ 950 $ 19 $ 45 , $ 50,291 $ 0 $ 0 $ 50,291
Investment Securities That Have Been in a Continuous Unrealized Loss Position for Less Than or Greater Than Twelve Months	A summary of investment securities that have been in a continuous unrealized loss position for less than or greater than twelve months is as follows: As of December 31, 2018 Less than 12 Months 12 Months or Longer Total (000’s omitted) # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses Available-for-Sale Portfolio: U.S. Treasury and agency securities 7 $ 473,082 $ 682 64 $ 1,213,276 $ 14,229 71 $ 1,686,358 $ 14,911 Obligations of state and political subdivisions 118 55,671 216 97 51,753 833 215 107,424 1,049 Government agency mortgage-backed securities 43 47,708 258 181 253,931 9,025 224 301,639 9,283 Corporate debt securities 0 0 0 1 2,546 42 1 2,546 42 Government agency collateralized mortgage obligations 1 66 0 41 63,112 1,283 42 63,178 1,283 Total available-for-sale investment portfolio 169 $ 576,527 $ 1,156 384 $ 1,584,618 $ 25,412 553 $ 2,161,145 $ 26,568 Equity and other Securities: Equity securities, at fair value 1 $ 82 $ 19 0 $ 0 $ 0 1 $ 82 $ 19 Total equity and other securities 1 $ 82 $ 19 0 $ 0 $ 0 1 $ 82 $ 19 As of December 31, 2017 Less than 12 Months 12 Months or Longer Total (000’s omitted) # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses # Fair Value Gross Unrealized Losses Available-for-Sale Portfolio: U.S. Treasury and agency securities 44 $ 699,709 $ 4,838 0 $ 0 $ 0 44 $ 699,709 $ 4,838 Obligations of state and political subdivisions 45 23,432 57 0 0 0 45 23,432 57 Government agency mortgage-backed securities 120 185,716 1,433 55 75,712 2,330 175 261,428 3,763 Corporate debt securities 1 2,623 25 0 0 0 1 2,623 25 Government agency collateralized mortgage obligations 39 80,041 878 1 1 0 40 80,042 878 Total available-for-sale investment portfolio 249 $ 991,521 $ 7,231 56 $ 75,713 $ 2,330 305 $ 1,067,234 $ 9,561
Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity	The amortized cost and estimated fair value of debt securities at December 31, 2018, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. Available-for-Sale (000’s omitted) Amortized Cost Fair Value Due in one year or less $ 58 , $ 58 , Due after one through five years 2 , , 2 , , Due after five years through ten years 158 , 160 , Due after ten years 149 , 151 , Subtotal 2,492 , 2,485 , Government agency mortgage-backed securities 390,234 382,477 Government agency collateralized mortgage obligations 69,342 68,119 Total $ 2 , , $ 2 , ,

LOANS (Tables)

LOANS (Tables)	12 Months Ended
	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Line Items]
Loans Receivable, Net	The balances of these classes at December 31 are summarized as follows: (000’s omitted) 2018 2017 Business lending $ 2,396,977 $ 2,424,223 Consumer mortgage 2,235,408 2,220,298 Consumer indirect 1,083,207 1,011,978 Consumer direct 178,820 179,929 Home equity 386,709 420,329 Gross loans, including deferred origination costs 6,281,121 6,256,757 Allowance for loan losses (49,284 ) (47,583 ) Loans, net of allowance for loan losses $ 6,231,837 $ 6,209,174
Aggregate Amounts Loaned to Related Parties	Following is a summary of the aggregate amount of such loans during 2018 and 2017. (000’s omitted) 2018 2017 Balance at beginning of year $ 22,344 $ 10,950 New loans 2,600 16,617 Payments (4,283 ) (5,223 ) Balance at end of year $ 20,661 $ 22,344
Outstanding Principal Balance and Related Carrying Amount of Acquired Loans	The outstanding principal balance and the related carrying amount of acquired loans included in the Consolidated Statement of Condition at December 31 are as follows: (000’s omitted) 2018 2017 Credit impaired acquired loans: Outstanding principal balance $ 6,936 $ 13,242 Carrying amount 5,446 10,115 Non-impaired acquired loans: Outstanding principal balance 1,271 , 1,658,780 Carrying amount 1,247 , 1,626,979 Total acquired loans: Outstanding principal balance 1,278 , 1,672,022 Carrying amount 1,253,137 1,637,094
Accretable Discount Related to Credit Impaired Acquired Loans	The changes in the accretable discount related to the credit impaired acquired loans are as follows: (000’s omitted) 2018 2017 Balance at beginning of year $ 976 $ 498 Merchants acquisition 0 793 Accretion recognized (783 ) (905 ) Net reclassification to accretable from nonaccretable 244 590 Balance at end of year $ 437 $ 976
Aged Analysis of Past Due Loans by Class	The following is an aged analysis of the Company’s past due loans by class as of December 31, 2018: Legacy Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Current Total Loans Business lending $ 5,261 $ 179 $ 4,872 $ 10,312 $ 1,608,515 $ 1,618,827 Consumer mortgage 12,468 1,393 9,872 23,733 1,824,717 1,848,450 Consumer indirect 14,609 258 0 14,867 1,057,525 1,072,392 Consumer direct 1,778 48 0 1,826 173,948 175,774 Home equity 983 228 1,438 2,649 309,892 312,541 Total $ 35,099 $ 2,106 $ 16,182 $ 53,387 $ 4,974,597 $ 5,027,984 Acquired Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Acquired Impaired (1) Current Total Loans Business lending $ 974 $ 0 $ 3,498 $ 4,472 $ 5,446 $ 768,232 $ 778,150 Consumer mortgage 841 232 2,390 3,463 0 383,495 386,958 Consumer indirect 78 34 0 112 0 10,703 10,815 Consumer direct 115 4 0 119 0 2,927 3,046 Home equity 613 79 474 1,166 0 73,002 74,168 Total $ 2,621 $ 349 $ 6,362 $ 9,332 $ 5,446 $ 1,238,359 $ 1,253,137 (1) Acquired impaired loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cashflows, is being recognized on all acquired impaired loans. The following is an aged analysis of the Company’s past due loans by class as of December 31, 2017: Legacy Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Still Accruing Nonaccrual Total Past Due Current Total Loans Business lending $ 2,283 $ 571 $ 3,944 $ 6,798 $ 1,369,801 $ 1,376,599 Consumer mortgage 13,564 1,500 10,722 25,786 1,728,823 1,754,609 Consumer indirect 14,197 295 0 14,492 977,344 991,836 Consumer direct 1,875 48 0 1,923 172,556 174,479 Home equity 1,116 94 1,354 2,564 319,576 322,140 Total $ 33,035 $ 2,508 $ 16,020 $ 51,563 $ 4,568,100 $ 4,619,663 Acquired Loans (000’s omitted) Past Due 30 - 89 days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Acquired (1) Current Total Loans Business lending $ 4,661 $ 0 $ 4,328 $ 8,989 $ 10,115 $ 1,028,520 $ 1,047,624 Consumer mortgage 2,603 26 3,066 5,695 0 459,994 465,689 Consumer indirect 245 8 0 253 0 19,889 20,142 Consumer direct 100 0 0 100 0 5,350 5,450 Home equity 634 170 1,326 2,130 0 96,059 98,189 Total $ 8,243 $ 204 $ 8,720 $ 17,167 $ 10,115 $ 1,609,812 $ 1,637,094 (1) Acquired impaired loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cashflows, is being recognized on all acquired impaired loans.
Non-Business Impaired Loans	A summary of individually evaluated impaired loans as of December 31, 2018 and 2017 is as follows: (000’s omitted) 2018 2017 Loans with allowance allocation $ 3,956 $ 5,125 Loans without allowance allocation 2,230 884 Carrying balance 6,186 6,009 Contractual balance 12,078 9,165 Specifically allocated allowance 956 804 Average impaired loans 7,618 9,517 Interest income recognized 0 0
Troubled Debt Restructurings on Financing Receivables	Information regarding TDRs as of December 31, 2018 and December 31, 2017 is as follows December 31, 2018 December 31, 2017 (000’s omitted) Nonaccrual Accruing Total Nonaccrual Accruing Total # Amount # Amount # Amount # Amount # Amount # Amount Business lending 4 $ 162 2 $ 165 6 $ 327 8 $ 218 7 $ 501 15 $ 719 Consumer mortgage 46 1,986 46 1,769 92 3,755 51 2,265 44 1,750 95 4,015 Consumer indirect 0 0 77 857 77 857 0 0 71 883 71 883 Consumer direct 0 0 22 71 22 71 0 0 25 69 25 69 Home equity 12 240 9 275 21 515 13 245 7 204 20 449 Total 62 $ 2,388 156 $ 3,137 218 $ 5,525 72 $ 2,728 154 $ 3,407 226 $ 6,135 The following table presents information related to loans modified in a TDR during the years ended December 31, 2018 and 2017. Of the loans noted in the table below, all loans for the years ended December 31, 2018 and December 31, 2017, were modified due to a Chapter 7 bankruptcy as described previously. The financial effects of these restructurings were immaterial. December 31, 2018 December 31, 2017 (000’s omitted) # Amount # Amount Business lending 2 $ 103 8 $ 412 Consumer mortgage 9 470 23 1,254 Consumer indirect 32 320 33 490 Consumer direct 6 24 6 17 Home equity 3 118 4 95 Total 52 $ 1,035 74 $ 2,268
Allowance for Loan Losses by Class	The allowance for loan losses is general in nature and is available to absorb losses from any loan type despite the analysis below. The following presents by class the activity in the allowance for loan losses: (000’s omitted) Business Lending Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Unallocated Acquired Impaired Total Balance at December 31, 2015 $ 15,749 $ 10,198 $ 12,422 $ 2,997 $ 2,666 $ 1,201 $ 168 $ 45,401 Charge-offs (1,872 ) (647 ) (7,643 ) (1,706 ) (218 ) 0 (97 ) (12,183 ) Recoveries 616 115 4,168 901 139 0 0 5,939 Provision 2,727 428 4,835 787 (188 ) (550 ) 37 8,076 Balance at December 31, 2016 17,220 10,094 13,782 2,979 2,399 651 108 47,233 Charge-offs (4,959 ) (707 ) (8,456 ) (2,081 ) (284 ) 0 (270 ) (16,757 ) Recoveries 656 50 4,516 849 52 0 0 6,123 Provision 4,340 1,028 3,626 1,292 (60 ) 449 309 10,984 Balance at December 31, 2017 17,257 10,465 13,468 3,039 2,107 1,100 147 47,583 Charge-offs (3,566 ) (836 ) (8,382 ) (1,777 ) (544 ) 0 (381 ) (15,486 ) Recoveries 485 136 4,874 807 48 0 0 6,350 Provision 4,346 359 4,406 1,026 533 (100 ) 267 10,837 Balance at December 31, 2018 $ 18,522 $ 10,124 $ 14,366 $ 3,095 $ 2,144 $ 1,000 $ 33 $ 49,284
Business Lending [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans by Credit Quality Indicator	The following table shows the amount of business lending loans by credit quality category: December 31, 2018 December 31, 2017 (000’s omitted) Legacy Acquired Total Legacy Acquired Total Pass $ 1,439,337 $ 702,493 $ 2,141,830 $ 1,170,156 $ 963,981 $ 2,134,137 Special mention 105,065 40,107 145,172 129,076 37,321 166,397 Classified 74,425 28,525 102,950 77,367 34,628 111,995 Doubtful 0 1,579 1,579 0 1,579 1,579 Acquired impaired 0 5,446 5,446 0 10,115 10,115 Total $ 1,618,827 $ 778,150 $ 2,396,977 $ 1,376,599 $ 1,047,624 $ 2,424,223
All Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans by Credit Quality Indicator	The following tables detail the balances in all loan categories except for business lending at December 31, 2018: Legacy loans (000’s omitted) Consumer Mortgage Consumer Consumer Direct Home Equity Total Performing $ 1,837,185 $ 1,072,134 $ 175,726 $ 310,875 $ 3,395,920 Nonperforming 11,265 258 48 1,666 13,237 Total $ 1,848,450 $ 1,072,392 $ 175,774 $ 312,541 $ 3,409,157 Acquired loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 384,336 $ 10,781 $ 3,042 $ 73,615 $ 471,774 Nonperforming 2,622 34 4 553 3,213 Total $ 386,958 $ 10,815 $ 3,046 $ 74,168 $ 474,987 The following table details the balances in all other loan categories at December 31, 2017: Legacy loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 1,742,387 $ 991,541 $ 174,431 $ 320,692 $ 3,229,051 Nonperforming 12,222 295 48 1,448 14,013 Total $ 1,754,609 $ 991,836 $ 174,479 $ 322,140 $ 3,243,064 Acquired loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 462,597 $ 20,134 $ 5,450 $ 96,693 $ 584,874 Nonperforming 3,092 8 0 1,496 4,596 Total $ 465,689 $ 20,142 $ 5,450 $ 98,189 $ 589,470

PREMISES AND EQUIPMENT (Tables)

PREMISES AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2018
PREMISES AND EQUIPMENT [Abstract]
Premises and Equipment	Premises and equipment consist of the following at December 31: (000’s omitted) 2018 2017 Land and land improvements $ 24,340 $ 23,869 Bank premises 133,259 131,647 Equipment and construction in progress 89 , 86,059 Premises and equipment, gross 247,549 241,575 Accumulated depreciation (127 , ) (118,182 ) Premises and equipment, net $ 119 , $ 123,393

GOODWILL AND IDENTIFIABLE INT_2

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2018
GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS [Abstract]
Gross Carrying Amount and Accumulated Amortization for Each Type of Identifiable Intangible Asset	The gross carrying amount and accumulated amortization for each type of identifiable intangible asset are as follows: December 31, 2018 December 31, 2017 (000’s omitted) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizing intangible assets: Core deposit intangibles $ 62,902 $ (44 , ) $ 18 , $ 62,902 $ (37,877 ) $ 25,025 Other intangibles 87,616 (32 , ) 55 , 86,535 (20,902 ) 65,633 Total amortizing intangibles $ 150,518 $ (76 , ) $ 73 , $ 149,437 $ (58,779 ) $ 90,658
Estimated Aggregate Amortization Expense for Each of Five Succeeding Fiscal Years	The estimated aggregate amortization expense for each of the five succeeding fiscal years ended December 31 is as follows: 2019 $ 15 , 2020 12 , 2021 10 , 2022 9 , 2023 7 , Thereafter 17 , Total $ 73 ,
Components of Goodwill	Shown below are the components of the Company’s goodwill at December 31, 2018 and 2017: (000’s omitted) Year Ended December 31, 2016 Activity Year Ended December 31, 2017 Activity Year Ended December 31, 2018 Goodwill $ 469,966 $ 269,288 $ 739,254 $ (927 ) $ 738,327 Accumulated impairment (4,824 ) 0 (4,824 ) 0 (4,824 ) Goodwill, net $ 465,142 $ 269,288 $ 734,430 $ (927 ) $ 733,503
Changes in Carrying Value of MSRs and Associated Valuation Allowance	The following table summarizes the changes in carrying value of MSRs and the associated valuation allowance: (000’s omitted) 2018 2017 Carrying value before valuation allowance at beginning of period $ 1,358 $ 1,435 Additions 228 358 Merchants acquisition 0 64 Amortization (449 ) (499 ) Carrying value before valuation allowance at end of period 1,137 1,358 Valuation allowance balance at beginning of period 0 0 Impairment charges 0 0 Impairment recoveries 0 0 Valuation allowance balance at end of period 0 0 Net carrying value at end of period $ 1,137 $ 1,358 Fair value of MSRs at end of period $ 2,397 $ 2,473 Principal balance of loans sold during the year $ 18,228 $ 32,937 Principal balance of loans serviced for others $ 333,862 $ 358,518 Custodial escrow balances maintained in connection with loans serviced for others $ 4,982 $ 5,363
Key Economic Assumptions Used to Estimate Value of MSRs	The following table summarizes the key economic assumptions used to estimate the value of the MSRs at December 31: 2018 2017 Weighted-average contractual life (in years) 21.4 21.3 Weighted-average constant prepayment rate (CPR) 9.3 % 11.1 % Weighted-average discount rate 3.6 % 3.3 %

DEPOSITS (Tables)

DEPOSITS (Tables)	12 Months Ended
	Dec. 31, 2018
DEPOSITS [Abstract]
Deposits	Deposits recorded in the consolidated statements of condition consist of the following at December 31: (000’s omitted) 2018 2017 Noninterest checking $ 2,312 , $ 2,293,057 Interest checking 1,920 , 1,830,914 Savings 1,448,208 1,421,512 Money market 1,901,262 2,124,633 Time 739 , 774,304 Total deposits $ 8,322 , $ 8,444,420
Interest on Deposits	Interest on deposits recorded in the consolidated statements of income consists of the following at December 31: (000’s omitted) 2018 2017 2016 Interest on interest checking $ 1,796 $ 1,032 $ 504 Interest on savings 858 841 863 Interest on money market 3,638 2,981 2,754 Interest on time 4,366 3,177 3,204 Total interest on deposits $ 10,658 $ 8,031 $ 7,325
Maturities of Time Deposits	The approximate maturities of time deposits at December 31, 2018 are as follows: (000’s omitted) All Accounts Accounts $250,000 or Greater 2019 $ 448,708 $ 40,960 2020 94,585 4,886 2021 123,021 20,100 2022 31,786 587 2023 41,223 3,087 Thereafter 217 0 Total $ 739 , $ 69 ,

BORROWINGS (Tables)

BORROWINGS (Tables)	12 Months Ended
	Dec. 31, 2018
BORROWINGS [Abstract]
Outstanding Borrowings	Outstanding borrowings at December 31 are as follows: (000’s omitted) 2018 2017 FHLB overnight advance $ 54 , $ 24,000 Subordinated debt held by unconsolidated subsidiary trusts, net of discount of $0 and $332, respectively 97 , 122,814 Securities sold under agreement to repurchase, short term 259 , 337,011 FHLB Long term advances 1 , 2,071 Total borrowings $ 413,682 $ 485,896
Borrowings by Contractual Maturity Dates	Borrowings at December 31, 2018 have contractual maturity dates as follows: (000’s omitted, except rate) Carrying Value Weighted-average Rate at December 31, 2018 January 2, 2019 $ 313,767 1.01 % July 3, 2023 575 2.25 % October 23, 2023 484 1.50 % October 1, 2025 315 1.50 % March 1, 2029 602 2.50 % December 15, 2034 20,619 4.74 % December 15, 2036 77,320 4.44 % Total $ 413,682 1.84 %
Terms of Preferred Securities	The terms of the preferred securities of each trust are as follows: Trust Issuance Date Par Amount Interest Rate Maturity Date Call Price CCT IV 12/8/2006 $75.0 million 3 month LIBOR plus 1.65% (4.44%) 12/15/2036 Par MBVT I 12/15/2004 $20.6 million 3 month LIBOR plus 1.95% (4.74%) 12/15/2034 Par

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2018
INCOME TAXES [Abstract]
Provision for Income Taxes	The provision for income taxes for the years ended December 31 is as follows: (000’s omitted) 2018 2017 2016 Current: Federal $ 32,504 $ 31,152 $ 32,829 State and other 9,180 6,788 4,890 Deferred: Federal 2,122 (28,146 ) 11,444 State and other 541 (546 ) 1,622 Provision for income taxes $ 44,347 $ 9,248 $ 50,785
Net Deferred Tax Liability	Components of the net deferred tax liability, included in other liabilities, as of December 31 are as follows: (000’s omitted) 2018 2017 Allowance for loan losses $ 12,131 $ 11,675 Employee benefits 4,479 4,216 Other, net 541 0 Deferred tax asset 17,151 15,891 Investment securities 14,451 22,690 Tax-deductible goodwill 39,540 39,154 Loan origination costs 6,851 6,109 Depreciation 3,098 2,372 Mortgage servicing rights 277 330 Pension 11,078 13,228 Other, net 0 542 Deferred tax liability 75,295 84,425 Net deferred tax liability $ (58,144 ) $ (68,534 )
Reconciliation of Differences between Federal Statutory Income Tax Rate and Effective Tax Rate	A reconciliation of the differences between the federal statutory income tax rate and the effective tax rate for the years ended December 31 is shown in the following table: 2018 2017 2016 Federal statutory income tax rate 21.0 % 35.0 % 35.0 % Increase (reduction) in taxes resulting from: Tax-exempt interest (1.6 ) (3.8 ) (4.0 ) State income taxes, net of federal benefit 3.4 2.5 2.7 Stock-based compensation (0.9 ) (2.0 ) 0 Federal deferred tax revaluation adjustment 0 (23.7 ) 0 Federal tax credits (1.4 ) (1.5 ) 0 Other, net 0.3 (0.7 ) (0.9 ) Effective income tax rate 20.8 % 5.8 % 32.8 %
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the unrecognized tax benefits for the years ended December 31 is shown in the following table: (000’s omitted) 2018 2017 2016 Unrecognized tax benefits at beginning of year $ 24 $ 92 $ 127 Changes related to: Lapse of statutes of limitations (24 ) (68 ) (35 ) Unrecognized tax benefits at end of year $ 0 $ 24 $ 92

BENEFIT PLANS (Tables)

BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2018
BENEFIT PLANS [Abstract]
Funded Status of Plans Reconciled with Amounts Reported in Consolidated Statements of Condition	Using a measurement date of December 31, the following table shows the funded status of the Company’s plans reconciled with amounts reported in the Company’s consolidated statements of condition: Pension Benefits Post-retirement Benefits (000’s omitted) 2018 2017 2018 2017 Change in benefit obligation: Benefit obligation at the beginning of year $ 147,450 $ 127,084 $ 1,785 $ 1,806 Service cost 4,561 4,181 0 0 Interest cost 5,676 5,717 69 76 Plan amendment / acquisition 883 11,646 0 0 Participant contributions 0 0 479 467 Deferred actuarial (gain)/loss (4,177 ) 8,978 191 245 Benefits paid (10,182 ) (10,156 ) (867 ) (809 ) Benefit obligation at end of year 144,211 147,450 1,657 1,785 Change in plan assets: Fair value of plan assets at beginning of year 217,107 180,400 0 0 Actual return of plan assets (3,858 ) 22,954 0 0 Participant contributions 0 0 479 467 Employer contributions 605 9,839 388 342 Plan acquisition 0 14,070 0 0 Benefits paid (10,182 ) (10,156 ) (867 ) (809 ) Fair value of plan assets at end of year 203,672 217,107 0 0 Over/(Under) funded status at year end $ 59,461 $ 69,657 $ (1,657 ) $ (1,785 ) Amounts recognized in the consolidated statement of condition were: Other assets $ 72,659 $ 81,000 $ 0 $ 0 Other liabilities (13,198 ) (11,343 ) (1,657 ) (1,785 ) Amounts recognized in accumulated other comprehensive loss/(income) (“AOCI”) were: Net loss $ 39,410 $ 26,935 $ 592 $ 420 Net prior service cost (credit) 4,939 2,944 (1,444 ) (1,622 ) Pre-tax AOCI 44,349 29,879 (852 ) (1,202 ) Taxes (10,870 ) (7,340 ) 210 296 AOCI at year end $ 33,479 $ 22,539 $ (642 ) $ (906 )
Amounts Recognized in Accumulated Other Comprehensive Income, Net of Tax	Amounts recognized in accumulated other comprehensive income, net of tax, for the year ended December 31, are as follows: Pension Benefits Post-retirement Benefits (000’s omitted) 2018 2017 2018 2017 Prior service cost/(credit) $ 1,509 $ 424 $ 135 $ 111 Net (gain) loss 9,431 (851 ) 129 148 Total $ 10,940 $ (427 ) $ 264 $ 259
Estimated Costs, Net of Tax, That Will Be Amortized from Accumulated Other Comprehensive (Income) Loss into Net Periodic (Income) Cost over Next Fiscal Year	The estimated costs, net of tax, that will be amortized from accumulated other comprehensive (income) loss into net periodic (income) cost over the next fiscal year are as follows: (000’s omitted) Pension Benefits Post-retirement Benefits Prior service credit $ 64 $ (179 ) Net loss 2,376 36 Total $ 2,440 $ (143 )
Weighted Average Assumptions Used To Determine Benefit Obligations	Pension Benefits Post-retirement Benefits 2018 2017 2018 2017 Discount rate 4.50 % 4.00 % 4.45 % 4.00 % Expected return on plan assets 7.00 % 7.00 % N/A N/A Rate of compensation increase 3.50 % 3.50 % N/A N/A
Net Periodic Benefit Cost	The net periodic benefit cost as of December 31 is as follows: Pension Benefits Post-retirement Benefits (000’s omitted) 2018 2017 2016 2018 2017 2016 Service cost $ 4,561 $ 4,181 $ 4,106 $ 0 $ 0 $ 0 Interest cost 5,676 5,717 5,624 69 76 82 Expected return on plan assets (14,820 ) (13,354 ) (11,842 ) 0 0 0 Plan amendment 13 0 20 0 0 0 Amortization of unrecognized net loss/(gain) 1,193 767 1,508 21 8 (5 ) Amortization of prior service cost (293 ) 55 43 (179 ) (179 ) (179 ) Net periodic (benefit) $ (3,670 ) $ (2,634 ) $ (541 ) $ (89 ) $ (95 ) $ (102 )
Weighted-Average Assumptions Used to Determine Benefit Obligations and Net Periodic Pension Cost	The weighted-average assumptions used to determine the net periodic pension cost for the years ended December 31 are as follows: Pension Benefits Post-retirement Benefits 2018 2017 2016 2018 2017 2016 Discount rate 4.00 % 4.40 % 4.70 % 4.00 % 4.40 % 4.70 % Expected return on plan assets 7.00 % 7.00 % 7.00 % N/A N/A N/A Rate of compensation increase 3.50 % 3.50 % 3.50 % N/A N/A N/A
Amount of Expected Benefit Payments	The amount of benefit payments that are expected to be paid over the next ten years are as follows: (000’s omitted) Pension Benefits Post-retirement Benefits 2019 $ 9,250 $ 175 2020 9,547 139 2021 10,142 136 2022 10,607 133 2023 11,092 130 2024-2028 59,372 598
Fair Value of Defined Benefit Plan Assets by Asset Category	The fair values of the Company’s defined benefit pension plan assets at December 31, 2018 by asset category are as follows: Asset category (000’s omitted) Quoted Prices in Active Markets for Identical Assets Level 1 Significant Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Total Cash equivalents $ 4,856 $ 0 $ 0 $ 4,856 Equity securities: U.S. large-cap 39,122 0 0 39,122 U.S mid/small cap 9,881 0 0 9,881 CBU stock 7,692 0 0 7,692 International 32,506 0 0 32,506 89,201 0 0 89,201 Fixed income securities: Government securities 64,417 11,370 0 75,787 Investment grade bonds 12,054 0 0 12,054 High yield (a) 6,712 0 0 6,712 83,183 11,370 0 94,553 Other investments (b) 14,267 66 0 14,333 Total (c) $ 191,507 $ 11,436 $ 0 $ 202,943 The fair values of the Company’s defined benefit pension plan assets at December 31, 2017 by asset category are as follows: Asset category (000’s omitted) Quoted Prices in Active Markets for Identical Assets Level 1 Significant Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Total Money Market Accounts $ 0 $ 10,381 $ 0 $ 10,381 Equity securities: U.S. large-cap 53,154 0 0 53,154 U.S mid/small cap 26,309 0 0 26,309 CBU stock 8,344 0 0 8,344 International 47,723 0 0 47,723 135,530 0 0 135,530 Fixed income securities: Government securities 13,929 9,686 0 23,615 Investment grade bonds 19,278 0 0 19,278 High yield (a) 16,297 0 0 16,297 49,504 9,686 0 59,190 Other investments (b) 11,302 73 0 11,375 Total (c) $ 196,336 $ 20,140 $ 0 $ 216,476 (a) This category is exchange-traded funds representing a diversified index of high yield corporate bonds. (b) This category is comprised of exchange-traded funds and mutual funds holding non-traditional investment classes including private equity funds and alternative exchange funds. (c) Excludes dividends and interest receivable totaling $0.7 million and $0.6 million at December 31, 2018 and 2017, respectively.

STOCK-BASED COMPENSATION PLANS

STOCK-BASED COMPENSATION PLANS (Tables)	12 Months Ended
	Dec. 31, 2018
STOCK-BASED COMPENSATION PLANS [Abstract]
Activity in Long-Term Incentive Program	Activity in this long-term incentive program is as follows: Stock Options Outstanding Weighted- average Exercise Price of Shares Outstanding at December 31, 2016 1,755,992 $ 30.85 Granted 197,943 57.02 Exercised (238,499 ) 25.72 Forfeited (7,140 ) 37.47 Outstanding at December 31, 2017 1,708,296 34.57 Granted 213,504 55.92 Exercised (268,004 ) 27.94 Forfeited (9,435 ) 45.54 Outstanding at December 31, 2018 1,644,361 $ 38.36 Exercisable at December 31, 2018 1,010,795 $ 32.66
Information about Stock Options Outstanding under Stock Option Plan	The following table summarizes the information about stock options outstanding under the Company’s stock option plan at December 31, 2018: Options outstanding Options exercisable Range of Exercise Price Shares Weighted -average Exercise Price Weighted- average Remaining Life (years) Shares Weighted -average Exercise Price $ 0.00 – $18.00 10,978 $ 17.82 0.31 10,978 $ 17.82 $ 18.001 – $28.00 215,014 23.26 2.67 215,014 23.26 $ 28.001 – $29.00 142,691 28.78 3.22 142,691 28.78 $ 29.001 – $30.00 185,866 29.79 4.21 185,866 29.79 $ 30.001 – $40.00 686,103 37.09 6.34 391,658 37.06 $ 40.001 – $60.00 403,709 56.45 8.73 64,588 56.72 TOTAL 1,644,361 $ 38.36 5.90 1,010,795 $ 32.66
Valuation Assumptions Used to Estimate Value of Stock Options	The Black-Scholes model requires several assumptions, which management developed based on historical trends and current market observations. 2018 2017 2016 Weighted-average Fair Value of Options Granted $ 13.44 $ 12.78 $ 7.90 Assumptions: Weighted-average expected life (in years) 6.50 6.50 6.50 Future dividend yield 2.91 % 3.19 % 3.43 % Share price volatility 29.44 % 29.71 % 30.00 % Weighted-average risk-free interest rate 2.82 % 2.31 % 1.72 %
Activity of Unvested Restricted Stock Awards	A summary of the status of the Company’s unvested restricted stock awards as of December 31, 2018, and changes during the twelve months ended December 31, 2018 and 2017, is presented below: Restricted Shares Weighted-average grant date fair value Unvested at December 31, 2016 253,830 $ 29.98 Awards 46,428 57.02 Forfeitures (4,863 ) 24.78 Vestings (64,522 ) 33.69 Unvested at December 31, 2017 230,873 34.06 Awards 50,133 55.92 Forfeitures (3,429 ) 34.95 Vestings (56,514 ) 39.40 Unvested at December 31, 2018 221,063 $ 37.72

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2018
EARNINGS PER SHARE [Abstract]
Reconciliation of Basic to Diluted Earnings per Share	The following is a reconciliation of basic to diluted earnings per share for the years ended December 31, 2018, 2017 and 2016. (000’s omitted, except per share data) 2018 2017 2016 Net income $ 168,641 $ 150,717 $ 103,812 Income attributable to unvested stock-based compensation awards (744 ) (597 ) (550 ) Income available to common shareholders $ 167,897 $ 15 0, 0 $ 103,262 Weighted-average common shares outstanding - basic 51 , 48 , 44,091 Basic earnings per share $ 3.28 $ 3 . $ 2.34 Net income $ 168,641 $ 150,717 $ 103,812 Income attributable to unvested stock-based compensation awards (744 ) (597 ) (550 ) Income available to common shareholders $ 167,897 $ 150,12 0 $ 103,262 Weighted-average common shares outstanding 51 , 48 , 44,091 Assumed exercise of stock options 583 627 394 Weighted-average common shares outstanding – diluted 51 , 49,470 44,485 Diluted earnings per share $ 3.24 $ 3.03 $ 2.32 Cash dividends declared per share $ 1.44 $ 1.32 $ 1.26

COMMITMENTS, CONTINGENT LIABI_2

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS (Tables)	12 Months Ended
	Dec. 31, 2018
COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS [Abstract]
Off Balance Sheet Financial Instruments Contract Amounts	The contract amounts of commitments and contingencies are as follows at December 31: (000’s omitted) 2018 2017 Commitments to extend credit $ 1,134 , $ 1,080,004 Standby letters of credit 33 , 23,782 Total $ 1,167 , $ 1,103,786

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2018
LEASES [Abstract]
Future Minimum Rental Commitments	The future minimum rental commitments as of December 31, 2018 for all non-cancelable operating leases are as follows: 2019 $ 8,452 2020 7,262 2021 5,673 2022 4,411 2023 2,621 Thereafter 10,390 Total $ 38,809

REGULATORY MATTERS (Tables)

REGULATORY MATTERS (Tables)	12 Months Ended
	Dec. 31, 2018
REGULATORY MATTERS [Abstract]
Capital Ratios and Amounts	Actual For capital adequacy purposes For capital adequacy purposes plus Capital Conservation Buffer To be well-capitalized under prompt corrective action (000’s omitted) Amount Ratio Amount Ratio Amount Ratio Amount Ratio Community Bank System, Inc.: 2018 Tier 1 Leverage ratio $ 1,093,166 11.08 % $ 394,700 4.00 % $ 493,375 5.00 % Tier 1 risk-based capital 1,093,166 18.23 % 359,747 6.00 % $ 472,168 7.875 % 479,662 8.00 % Total risk-based capital 1,142,927 19.06 % 479,662 8.00 % 592,083 9.875 % 599,578 10.00 % Common equity tier 1 capital 998,111 16.65 % 269,810 4.50 % 382,231 6.375 % 389,726 6.50 % 2017 Tier 1 Leverage ratio $ 995,860 10.00 % $ 398,183 4.00 % $ 497,729 5.00 % Tier 1 risk-based capital 995,860 16.64 % 358,988 6.00 % $ 433,777 7.25 % 478,651 8.00 % Total risk-based capital 1,043,910 17.45 % 478,651 8.00 % 553,440 9.25 % 598,314 10.00 % Common equity tier 1 capital 876,685 14.65 % 269,241 4.50 % 344,030 5.75 % 388,904 6.50 % Community Bank, N.A.: 2018 Tier 1 Leverage ratio $ 912,995 9.32 % $ 391,953 4.00 % $ 489,941 5.00 % Tier 1 risk-based capital 912,995 15.35 % 356,973 6.00 % $ 468,527 7.875 % 475,964 8.00 % Total risk-based capital 962,756 16.18 % 475,964 8.00 % 587,518 9.875 % 594,955 10.00 % Common equity tier 1 capital 912,940 15.35 % 267,730 4.50 % 379,284 6.375 % 386,721 6.50 % 2017 Tier 1 Leverage ratio $ 859,538 8.71 % $ 394,981 4.00 % $ 493,726 5.00 % Tier 1 risk-based capital 859,538 14.50 % 355,641 6.00 % $ 429,733 7.25 % 474,188 8.00 % Total risk-based capital 907,588 15.31 % 474,188 8.00 % 548,280 9.25 % 592,736 10.00 % Common equity tier 1 capital 859,483 14.50 % 266,731 4.50 % 340,823 5.75 % 385,278 6.50 %

PARENT COMPANY STATEMENTS (Tabl

PARENT COMPANY STATEMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
PARENT COMPANY STATEMENTS [Abstract]
Condensed Statements of Condition of Parent Company	The condensed statements of condition of the parent company, Community Bank System, Inc., at December 31 are as follows: (000’s omitted) 2018 2017 Assets: Cash and cash equivalents $ 116,133 $ 84,460 Investment securities 3,452 4,322 Investment in and advances to: Bank subsidiary 1,522,109 1,511,780 Non-bank subsidiaries 182,617 169,341 Other assets 8,957 9,150 Total assets $ 1,833,268 $ 1,779,053 Liabilities and shareholders’ equity: Accrued interest and other liabilities $ 21,546 $ 20,924 Borrowings 97,939 122,814 Shareholders’ equity 1,713,783 1,635,315 Total liabilities and shareholders’ equity $ 1,833,268 $ 1,779,053
Condensed Statements of Income of Parent Company	The condensed statements of income of the parent company for the years ended December 31 is as follows: (000’s omitted) 2018 2017 2016 Revenues: Dividends from subsidiaries: Bank subsidiary $ 98,000 $ 91,000 $ 89,000 Non-bank subsidiaries 9,250 35,500 1,750 Interest and dividends on investments 161 133 102 Total revenues 107,411 126,633 90,852 Expenses: Interest on borrowings 4,677 3,904 2,949 Acquisition expenses 0 91 429 Loss on debt prepayment 318 0 0 Other expenses 131 26 11 Total expenses 5,126 4,021 3,389 Income before tax benefit and equity in undistributed net income of subsidiaries 102,285 122,612 87,463 Income tax benefit 1,330 1,930 866 Income before equity in undistributed net income of subsidiaries 103,615 124,542 88,329 Equity in undistributed net income of subsidiaries 65,026 26,175 15,483 Net income $ 168,641 $ 150,717 $ 103,812 Other comprehensive (loss), net of tax: Changes in other comprehensive (loss)/income related to pension and other post retirement obligations (11,204 ) 168 3,322 Changes in other comprehensive loss related to unrealized losses on available-for-sale securities (30,402 ) (11,065 ) (14,714 ) Other comprehensive loss (41,606 ) (10,897 ) (11,392 ) Comprehensive income $ 127,035 $ 139,820 $ 92,420
Statements of Cash Flows of Parent Company	The statements of cash flows of the parent company for the years ended December 31 is as follows: (000’s omitted) 2018 2017 2016 Operating activities: Net income $ 168 , $ 150,717 $ 103,812 Adjustments to reconcile net income to net cash provided by operating activities Equity in undistributed net income of subsidiaries (65 , ) (26,175 ) (15,483 ) Net change in other assets and other liabilities (1,084 ) 1,870 (215 ) Net cash provided by operating activities 102,531 126,412 88,114 Investing activities: Proceeds from redemption of investment securities 776 0 0 Cash paid for acquisitions, net of cash acquired of $0, $150,534, and $0, respectively 0 (139,471 ) 0 Capital contributions to subsidiaries 0 (11,063 ) 0 Net cash provided by/(used in) investing activities 776 (150,534 ) 0 Financing activities: Repayment of borrowings (25,207 ) 0 0 Issuance of common stock 12 , 0 9,700 15,326 Purchase of treasury stock (298 ) (3,306 ) (3,470 ) Sale of treasury stock 12 , 10,060 8,888 Increase in deferred compensation arrangements 298 3,306 0 Cash dividends paid (71 , ) (62,305 ) (55,048 ) Net cash used in financing activities (71 , ) (42,545 ) (34,304 ) Change in cash and cash equivalents 31,673 (66,667 ) 53,81 0 Cash and cash equivalents at beginning of year 84,460 151,127 97,317 Cash and cash equivalents at end of year $ 116 , $ 84,460 $ 151,127 Supplemental disclosures of cash flow information: Cash paid for interest $ 4 , $ 3,826 $ 2,909 Supplemental disclosures of noncash financing activities Dividends declared and unpaid $ 19 , $ 17,460 $ 14,268 Capital contributions to subsidiaries 0 513,769 0 Common stock issued for acquisition 0 343,132 0

FAIR VALUE (Tables)

FAIR VALUE (Tables)	12 Months Ended
	Dec. 31, 2018
FAIR VALUE [Abstract]
Fair Value Measured on a Recurring Basis	The following tables set forth the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis. There were no transfers between any of the levels for the periods presented. December 31, 2018 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,896,931 $ 126,822 $ 0 $ 2,023,753 Obligations of state and political subdivisions 0 459,154 0 459,154 Government agency mortgage-backed securities 0 382,477 0 382,477 Corporate debt securities 0 2,546 0 2,546 Government agency collateralized mortgage obligations 0 68,119 0 68,119 Total available-for-sale investment securities 1,896,931 1,039,118 0 2,936,049 Equity securities 432 0 0 432 Mortgage loans held for sale 0 83 0 83 Interest rate swap agreements asset 0 793 0 793 Interest rate swap agreements liability 0 (742 ) 0 (742 ) Total $ 1,897,363 $ 1,039,252 $ 0 $ 2,936,615 December 31, 2017 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,909,290 $ 144,781 $ 0 $ 2,054,071 Obligations of state and political subdivisions 0 528,956 0 528,956 Government agency mortgage-backed securities 0 357,538 0 357,538 Corporate debt securities 0 2,623 0 2,623 Government agency collateralized mortgage obligations 0 87,374 0 87,374 Marketable equity securities 526 0 0 526 Total available-for-sale investment securities 1,909,816 1,121,272 0 3,031,088 Mortgage loans held for sale 0 461 0 461 Commitments to originate real estate loans for sale 0 0 89 89 Forward sales commitments 0 4 0 4 Interest rate swap agreements asset 0 1,064 0 1,064 Interest rate swap agreements liability 0 (904 ) 0 (904 ) Total $ 1,909,816 $ 1,121,897 $ 89 $ 3,031,802
Assets and Liabilities Measured on a Non-Recurring Basis	Assets and liabilities measured on a non-recurring basis: December 31, 2018 December 31, 2017 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Impaired loans $ 0 $ 0 $ 1,102 $ 1,102 $ 0 $ 0 $ 0 $ 0 Other real estate owned 0 0 1,320 1,320 0 0 1,915 1,915 Total $ 0 $ 0 $ 2,422 $ 2,422 $ 0 $ 0 $ 1,915 $ 1,915
Significant Unobservable Inputs, Fair Value Valuation Techniques	The significant unobservable inputs used in the determination of fair value of assets classified as Level 3 on a recurring or non-recurring basis as of December 31, 2018 are as follows: (000's omitted) Fair Value Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Impaired loans $ 1,102 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 35.4% (28.8 %) Other real estate owned 1,320 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 69 . . %) The significant unobservable inputs used in the determination of fair value of assets classified as Level 3 on a recurring or non-recurring basis as of December 31, 2017 are as follows: (000's omitted) Fair Value Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Other real estate owned $ 1,915 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 99.0% (38.5 %) Commitments to originate real estate loans for sale 89 Discounted cash flow Embedded servicing value 1 %
Carrying Amounts and Estimated Fair Values of Other Financial Instruments	The carrying amounts and estimated fair values of the Company’s other financial instruments that are not accounted for at fair value at December 31, 2018 and 2017 are as follows: December 31, 2018 December 31, 2017 (000's omitted) Carrying Value Fair Value Carrying Value Fair Value Financial assets: Net loans $ 6,231,837 $ 6,247,939 $ 6,209,174 $ 6,244,941 Financial liabilities: Deposits 8,322,371 8,308,765 8,444,420 8,431,481 Short-term borrowings 54,400 54,400 24,000 24,000 Securities sold under agreement to repurchase, short-term 259,367 259,367 337,011 337,011 Other long-term debt 1,976 1,921 2,071 2,021 Subordinated debt held by unconsolidated subsidiary trusts 97,939 97,939 122,814 122,814

VARIABLE INTEREST ENTITIES (Tab

VARIABLE INTEREST ENTITIES (Tables)	12 Months Ended
	Dec. 31, 2018
VARIABLE INTEREST ENTITIES [Abstract]
Carrying Amount and Classification of Assets and Liabilities of 706 North Clinton	The carrying amount of the assets and liabilities of 706 North Clinton and the classification of these assets and liabilities in the Company’s consolidated statements of condition at December 31 is as follows: (000’s omitted) 2018 2017 Cash and cash equivalents $ 104 $ 74 Premises and equipment, net 6,109 6,266 Other assets 33 5 Total assets $ 6,246 $ 6,345 Total liabilities $ 0 $ 0

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2018
SEGMENT INFORMATION [Abstract]
Schedule of Segment Reporting Information by Segment	Information about reportable segments and reconciliation of the information to the consolidated financial statements follows: (000’s omitted) Banking Employee Benefit Services All Other Eliminations Consolidated Total 2018 Net interest income $ 344,551 $ 376 $ 128 $ 0 $ 345,055 Provision for loan losses 10,837 0 0 0 10,837 Noninterest revenue 75,399 94,449 57,204 (2,993 ) 224,059 Amortization of intangible assets 6,429 8,015 3,711 0 18,155 Acquisition expenses (782 ) 7 6 0 (769 ) Other operating expenses 231,362 56,275 43,259 (2,993 ) 327,903 Income before income taxes $ 172,104 $ 30,528 $ 10,356 $ 0 $ 212,988 Assets $ 10,397,623 $ 207,460 $ 68,288 $ (66,076 ) $ 10,607,295 Goodwill $ 629,916 $ 83,275 $ 20,312 $ 0 $ 733,503 Core deposit intangibles & Other intangibles $ 18,596 $ 44,545 $ 10,705 $ 0 $ 73,846 2017 Net interest income $ 315,025 $ 396 $ 254 $ 0 $ 315,675 Provision for loan losses 10,984 0 0 0 10,984 Noninterest revenue 73,337 82,743 49,201 (2,858 ) 202,423 Amortization of intangible assets 5,296 8,578 3,067 0 16,941 Acquisition expenses 24,549 1,194 243 0 25,986 Other operating expenses 218,608 51,138 37,334 (2,858 ) 304,222 Income before income taxes $ 128,925 $ 22,229 $ 8,811 $ 0 $ 159,965 Assets $ 10,505,919 $ 203,369 $ 66,548 $ (29,638 ) $ 10,746,198 Goodwill $ 629,916 $ 84,449 $ 20,065 $ 0 $ 734,430 Core deposit intangibles & Other intangibles $ 25,025 $ 52,288 $ 13,345 $ 0 $ 90,658 2016 Net interest income $ 273,542 $ 162 $ 192 $ 0 $ 273,896 Provision for loan losses 8,076 0 0 0 8,076 Noninterest revenue 66,059 48,261 43,747 (2,442 ) 155,625 Amortization of intangible assets 2,682 420 2,377 0 5,479 Acquisition expenses 1,005 445 256 0 1,706 Other operating expenses 190,263 36,892 34,950 (2,442 ) 259,663 Income before income taxes $ 137,575 $ 10,666 $ 6,356 $ 0 $ 154,597 Assets $ 8,598,057 $ 38,742 $ 71,428 $ (41,790 ) $ 8,666,437 Goodwill $ 440,870 $ 8,019 $ 16,253 $ 0 $ 465,142 Core deposit intangibles & Other intangibles $ 7,107 $ 666 $ 7,929 $ 0 $ 15,702

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)SubsidiaryTrustBranchCountyComponentTypeCalculationSegmentFactor	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 01, 2019USD ($)
Nature of Operations [Abstract]
Number of significant consolidated subsidiaries owned | Subsidiary	2
Number of unconsolidated subsidiary business trusts owned | Trust	2
Number of bank branches | Branch	224
Risks and Uncertainties [Abstract]
Number of main components of economic risk | Component	3
Wealth Management Services [Abstract]
Number of types of performance obligations | Type	2
Contract Balances [Abstract]
Accounts receivable	$ 26,400	$ 29,800
Unbilled fee revenue	7,800	6,500
Unearned revenue	2,200	3,900
Cash and Cash Equivalents [Abstract]
Cash due from banks	$ 15,000	36,000
Impaired and Other Nonaccrual Loans [Abstract]
Number of days past due for loans to be placed on nonaccrual status	90 days
Period for which a nonaccrual TDR loan remains on nonaccrual status	12 months
Allowance for Loan Losses [Abstract]
Number of broad components used in allowance methodology | Component	2
Number of calculations used for general loan loss allocations | Calculation	2
Number of main loan segments | Segment	5
Period of historical net charge-off data for each loan class used in determining allowance level	36 months
Number of qualitative environmental factors used in qualitative calculation for general loan loss allocations | Factor	8
Other Real Estate [Abstract]
Other real estate	$ 1,300	1,900
Advertising [Abstract]
Advertising costs	5,100	5,700	$ 3,900
Recently Adopted Accounting Pronouncements [Abstract]
Reclassification of other comprehensive income to retained earnings		0
Salaries and employee benefits	207,363	186,903	156,396
Other expenses	21,471	22,609	22,749
Retained Earnings [Member]
Recently Adopted Accounting Pronouncements [Abstract]
Reclassification of other comprehensive income to retained earnings		208
Accumulated Other Comprehensive Income/(Loss) [Member]
Recently Adopted Accounting Pronouncements [Abstract]
Reclassification of other comprehensive income to retained earnings		(208)
ASU 2014-01 [Member]
Investments in Real Estate Limited Partnerships [Abstract]
Unfunded commitments	2,000
Impairment losses related to real estate partnerships	0
ASU 2016-01 [Member] | Retained Earnings [Member]
Recently Adopted Accounting Pronouncements [Abstract]
Reclassification of other comprehensive income to retained earnings	208
ASU 2016-01 [Member] | Accumulated Other Comprehensive Income/(Loss) [Member]
Recently Adopted Accounting Pronouncements [Abstract]
Reclassification of other comprehensive income to retained earnings	$ (208)
ASU 2016-02 [Member] | Plan [Member]
Recently Adopted Accounting Pronouncements [Abstract]
Right to use assets				$ 33,500
Lease liability				$ 33,500
ASU 2017-07 [Member]
Recently Adopted Accounting Pronouncements [Abstract]
Salaries and employee benefits		(6,900)	(4,700)
Other expenses		$ 6,900	$ 4,700
Investments in Real Estate Limited Partnerships [Member] | Minimum [Member]
Investments in Real Estate Limited Partnerships [Abstract]
Ownership interest	5.00%
Investments in Real Estate Limited Partnerships [Member] | Maximum [Member]
Investments in Real Estate Limited Partnerships [Abstract]
Ownership interest	99.99%
Upstate New York [Member]
Nature of Operations [Abstract]
Number of counties where the bank has facilities | County	35
Northeastern Pennsylvania [Member]
Nature of Operations [Abstract]
Number of counties where the bank has facilities | County	6
Vermont [Member]
Nature of Operations [Abstract]
Number of counties where the bank has facilities | County	12
Western Massachusetts [Member]
Nature of Operations [Abstract]
Number of counties where the bank has facilities | County	1
Consumer Installment Loans [Member]
Impaired and Other Nonaccrual Loans [Abstract]
Number of days past due after which loans are charged off to the extent outstanding principal balance exceeds fair value of collateral/property	90 days
Consumer Mortgage Loans [Member]
Impaired and Other Nonaccrual Loans [Abstract]
Number of days past due after which loans are charged off to the extent outstanding principal balance exceeds fair value of collateral/property	180 days
Home Equity Loans [Member]
Impaired and Other Nonaccrual Loans [Abstract]
Number of days past due after which loans are charged off to the extent outstanding principal balance exceeds fair value of collateral/property	180 days
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	3 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	10 years
Software [Member] | Minimum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	3 years
Software [Member] | Maximum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	7 years
Hardware [Member] | Minimum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	3 years
Hardware [Member] | Maximum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	7 years
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	10 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	40 years
Land Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Gross [Abstract]
Estimated useful life	20 years
BPAS [Member]
Nature of Operations [Abstract]
Number of significant consolidated subsidiaries owned | Subsidiary	5
Hand Benefits & Trust [Member]
Nature of Operations [Abstract]
Number of significant consolidated subsidiaries owned | Subsidiary	1
NRS [Member]
Nature of Operations [Abstract]
Number of significant consolidated subsidiaries owned | Subsidiary	1
Core Deposits [Member] | Minimum [Member]
Intangible Assets [Abstract]
Intangible asset useful life (amortization period)	7 years
Core Deposits [Member] | Maximum [Member]
Intangible Assets [Abstract]
Intangible asset useful life (amortization period)	20 years
Customer Relationships [Member] | Minimum [Member]
Intangible Assets [Abstract]
Intangible asset useful life (amortization period)	7 years
Customer Relationships [Member] | Maximum [Member]
Intangible Assets [Abstract]
Intangible asset useful life (amortization period)	20 years
Commercial Portfolio Segment [Member] | Minimum [Member]
Impaired and Other Nonaccrual Loans [Abstract]
Threshold balance of loans individually evaluated for impairment	$ 500

ACQUISITIONS (Details)

ACQUISITIONS (Details) shares in Thousands, $ in Thousands

Apr. 02, 2018USD ($)

Jan. 02, 2018USD ($)

Dec. 04, 2017USD ($)shares

Nov. 17, 2017USD ($)

May 12, 2017USD ($)Branchshares

Mar. 01, 2017USD ($)

Feb. 03, 2017USD ($)

Jan. 01, 2017USD ($)

Dec. 31, 2018USD ($)

Jun. 30, 2018USD ($)

Mar. 31, 2018USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Jan. 02, 2017USD ($)

Acquisitions [Abstract]

Cash

$ 1,737

$ 107,414

$ 575

Goodwill

$ 733,503

733,503

734,430

$ 465,142

HR Consultants (SA), LLC [Member]

Acquisitions [Abstract]

Cash

$ 300

HR Consultants (SA), LLC [Member] | Customer Lists [Member]

Acquisitions [Abstract]

Intangibles

$ 300

Penna & Associates Agency, Inc. [Member]

Acquisitions [Abstract]

Cash

$ 800

Goodwill

300

Penna & Associates Agency, Inc. [Member] | Customer Lists [Member]

Acquisitions [Abstract]

Intangibles

300

Styles Bridges Associates [Member]

Acquisitions [Abstract]

Cash

700

Styles Bridges Associates [Member] | Customer Lists [Member]

Acquisitions [Abstract]

Intangibles

$ 700

Gordon B. Roberts Agency, Inc [Member]

Acquisitions [Abstract]

Cash

$ 1,350

Purchase price of acquisition

$ 3,700

Issuance of common shares (in shares) | shares

40

Assets acquired

$ 600

Other liabilities

600

Goodwill

2,100

Increase (decrease) in other liabilities as a result of reclassification and adjustment

20

$ (90)

Increase (decrease) in goodwill as a result of fair value adjustment

$ 20

$ (90)

Gordon B. Roberts Agency, Inc [Member] | Other Intangibles [Member]

Acquisitions [Abstract]

Intangibles

$ 1,600

Northeast Capital Management, Inc [Member]

Acquisitions [Abstract]

Cash

$ 1,200

Northeast Capital Management, Inc [Member] | Customer Lists [Member]

Acquisitions [Abstract]

Intangibles

$ 1,200

Dryfoos [Member]

Acquisitions [Abstract]

Cash

$ 3,000

Goodwill

1,700

Dryfoos [Member] | Other Intangibles [Member]

Acquisitions [Abstract]

Intangibles

$ 1,700

BAS [Member]

Acquisitions [Abstract]

Cash

$ 1,200

BAS [Member] | Other Intangibles [Member]

Acquisitions [Abstract]

Intangibles

$ 1,200

Merchants Bancshares, Inc. [Member]

Acquisitions [Abstract]

Cash

$ 82,898

Purchase price of acquisition

$ 345,152

Issuance of common shares (in shares) | shares

4,680

Assets acquired

$ 2,000,000

Other liabilities

11,750

Goodwill

$ 189,046

Revenue earned

61,200

42,600

Expenses incurred

$ 30,800

19,900

Merchants Bancshares, Inc. [Member] | Vermont [Member]

Acquisitions [Abstract]

Number of branch locations added upon merger | Branch

31

Merchants Bancshares, Inc. [Member] | Massachusetts [Member]

Acquisitions [Abstract]

Number of branch locations added upon merger | Branch

1

Merchants Bancshares, Inc. [Member] | Other Intangibles [Member]

Acquisitions [Abstract]

Intangibles

$ 2,857

Northeast Retirement Services, Inc. [Member]

Acquisitions [Abstract]

Cash

$ 70,073

Purchase price of acquisition

148,556

Tangible assets, net

$ 36,100

Factor of straight-line rate of depreciation used in declining balance depreciation method

150.00%

Period of amortization

10 years

Deferred tax liability

$ 23,000

Other liabilities

26,828

Goodwill

75,256

Revenue earned

$ 40,600

31,500

Expenses incurred

$ 24,600

$ 21,500

Increase (decrease) in other liabilities as a result of reclassification and adjustment

$ (1,200)

Increase (decrease) in goodwill as a result of fair value adjustment

$ (1,200)

Northeast Retirement Services, Inc. [Member] | Other Intangibles [Member]

Acquisitions [Abstract]

Intangibles

$ 60,200

ACQUISITIONS, Estimated Fair Va

ACQUISITIONS, Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Apr. 02, 2018	[1]	May 12, 2017	Feb. 03, 2017	Jan. 04, 2016	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Consideration paid [Abstract]
Cash						$ 1,737		$ 107,414	$ 575
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Goodwill						733,503		$ 734,430	$ 465,142
NRS [Member]
Consideration paid [Abstract]
Cash				$ 70,073
Community Bank System, Inc. common stock				78,483
Total net consideration paid				148,556
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents				11,063
Investment securities				20,294
Loans				0
Premises and equipment				411
Accrued interest receivable				72
Other assets				8,088
Deposits				0
Other liabilities				(26,828)
Short-term advances				0
Securities sold under agreement to repurchase, short-term				0
Long-term debt				0
Subordinated debt held by unconsolidated subsidiary trusts				0
Total identifiable assets, net				73,300
Goodwill				75,256
NRS [Member] | Core Deposits [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles				0
NRS [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles				$ 60,200
Merchants Bancshares, Inc. [Member]
Consideration paid [Abstract]
Cash			$ 82,898
Community Bank System, Inc. common stock			262,254
Total net consideration paid			345,152
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents			40,730
Investment securities			370,648
Loans			1,488,157
Premises and equipment			16,608
Accrued interest receivable			4,773
Other assets			51,585
Deposits			(1,448,406)
Other liabilities			(11,750)
Short-term advances			(80,000)
Securities sold under agreement to repurchase, short-term			(278,076)
Long-term debt			(3,615)
Subordinated debt held by unconsolidated subsidiary trusts			(20,619)
Total identifiable assets, net			156,106
Goodwill			189,046
Merchants Bancshares, Inc. [Member] | Core Deposits [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles			23,214
Merchants Bancshares, Inc. [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles			$ 2,857
WJL Agencies Inc [Member]
Consideration paid [Abstract]
Cash					$ 575
Community Bank System, Inc. common stock					0
Total net consideration paid					575
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents					0
Investment securities					0
Loans					0
Premises and equipment					0
Accrued interest receivable					0
Other assets					0
Deposits					0
Other liabilities					0
Short-term advances					0
Securities sold under agreement to repurchase, short-term					0
Long-term debt					0
Subordinated debt held by unconsolidated subsidiary trusts					0
Total identifiable assets, net					288
Goodwill					287
WJL Agencies Inc [Member] | Core Deposits [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles					0
WJL Agencies Inc [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles					$ 288
Other [Member]
Consideration paid [Abstract]
Cash	$ 1,753					6,775	[2]
Community Bank System, Inc. common stock	0					2,395	[2]
Total net consideration paid	1,753					9,170	[2]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents	16					339	[2]
Investment securities	0					0	[2]
Loans	0					0	[2]
Premises and equipment	10					27	[2]
Accrued interest receivable	0					0	[2]
Other assets	105					583	[2]
Deposits	0					0	[2]
Other liabilities	(31)					(1,155)	[2]
Short-term advances	0					0	[2]
Securities sold under agreement to repurchase, short-term	0					0	[2]
Long-term debt	0					0	[2]
Subordinated debt held by unconsolidated subsidiary trusts	0					0	[2]
Total identifiable assets, net	1,443					5,420	[2]
Goodwill	310					3,750	[2]
Other [Member] | Core Deposits [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles	0					0	[2]
Other [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles	$ 1,343					5,626	[2]
Total [Member]
Consideration paid [Abstract]
Cash						159,746
Community Bank System, Inc. common stock						343,132
Total net consideration paid						502,878
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents						52,132
Investment securities						390,942
Loans						1,488,157
Premises and equipment						17,046
Accrued interest receivable						4,845
Other assets						60,256
Deposits						(1,448,406)
Other liabilities						(39,733)
Short-term advances						(80,000)
Securities sold under agreement to repurchase, short-term						(278,076)
Long-term debt						(3,615)
Subordinated debt held by unconsolidated subsidiary trusts						(20,619)
Total identifiable assets, net						234,826
Goodwill						268,052
Total [Member] | Core Deposits [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles						23,214
Total [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles						$ 68,683
[1]	Includes amounts related to the Penna, Styles Bridges and HR Consultants acquisitions.
[2]	Includes amounts related to the BAS, Dryfoos, NECM and GBR acquisitions.

ACQUISITIONS, Summary of Loans

ACQUISITIONS, Summary of Loans Acquired (Details) - Merchants Bancshares, Inc. [Member] $ in Thousands	May 12, 2017USD ($)
Summary of loans acquired [Abstract]
Contractually required principal and interest at acquisition	$ 1,888,028
Contractual cash flows not expected to be collected	(20,138)
Expected cash flows at acquisition	1,867,890
Interest component of expected cash flows	(379,733)
Fair value of acquired loans	1,488,157
Acquired Impaired Loans [Member]
Summary of loans acquired [Abstract]
Contractually required principal and interest at acquisition	15,454
Contractual cash flows not expected to be collected	(5,385)
Expected cash flows at acquisition	10,069
Interest component of expected cash flows	(793)
Fair value of acquired loans	9,276
Acquired Non Impaired Loans [Member]
Summary of loans acquired [Abstract]
Contractually required principal and interest at acquisition	1,872,574
Contractual cash flows not expected to be collected	(14,753)
Expected cash flows at acquisition	1,857,821
Interest component of expected cash flows	(378,940)
Fair value of acquired loans	$ 1,478,881

ACQUISITIONS, Intangible Asset,

ACQUISITIONS, Intangible Asset, Goodwill and Acquisition-related Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of loans acquired [Abstract]
Merger and acquisition integration related (recoveries) expenses	$ (769)	$ 25,986	$ 1,706
Penna & Associates Agency, Inc. [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Penna & Associates Agency, Inc. [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Styles Bridges Associates [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Styles Bridges Associates [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
HR Consultants (SA), LLC [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
HR Consultants (SA), LLC [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Merchants Bancshares, Inc. [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Merchants Bancshares, Inc. [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Dryfoos [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Dryfoos [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
BAS [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
BAS [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Northeast Capital Management, Inc [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Northeast Capital Management, Inc [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Gordon B. Roberts Agency, Inc [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
Gordon B. Roberts Agency, Inc [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
WJL Agencies Inc [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years
WJL Agencies Inc [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life	8 years

ACQUISITIONS, Supplemental Pro

ACQUISITIONS, Supplemental Pro Forma Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Supplemental Pro Forma Financial Information [Abstract]
Acquisitions-related expenses	$ 25,700
Total revenue, net of interest expense, pro forma	546,977	$ 536,183
Net income, pro forma	$ 176,257	$ 109,186

INVESTMENT SECURITIES, Availabl

INVESTMENT SECURITIES, Available-for-Sale Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available-for-Sale Portfolio [Abstract]
Amortized cost	$ 2,952,278	$ 3,007,148
Gross unrealized gains	10,339	33,501
Gross unrealized losses	26,568	9,561
Fair value	2,936,049	3,031,088
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	2,952,278
Fair value	2,936,049
U.S. Treasury and Agency Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	2,036,474	2,043,023
Gross unrealized gains	2,190	15,886
Gross unrealized losses	14,911	4,838
Fair value	2,023,753	2,054,071
Obligations of State and Political Subdivisions [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	453,640	514,949
Gross unrealized gains	6,563	14,064
Gross unrealized losses	1,049	57
Fair value	459,154	528,956
Government Agency Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	390,234	358,180
Gross unrealized gains	1,526	3,121
Gross unrealized losses	9,283	3,763
Fair value	382,477	357,538
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	2,588	2,648
Gross unrealized gains	0	0
Gross unrealized losses	42	25
Fair value	2,546	2,623
Government Agency Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	69,342	88,097
Gross unrealized gains	60	155
Gross unrealized losses	1,283	878
Fair value	68,119	87,374
Marketable Equity Security [Member]
Marketable Equity Securities [Abstract]
Amortized cost	0	251
Gross unrealized gains	0	275
Gross unrealized losses	0	0
Fair value	$ 0	$ 526

INVESTMENT SECURITIES, Equity a

INVESTMENT SECURITIES, Equity and Other Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Equity and Other Securities [Abstract]
Amortized cost	$ 44,678	$ 50,291
Gross unrealized gains	950	0
Gross unrealized losses	19	0
Fair value	45,609	50,291
Equity Securities, at Fair Value [Abstract]
Amortized cost	251	0
Gross unrealized gains	200	0
Gross unrealized losses	19	0
Fair value	432	0
Federal Home Loan Bank Common Stock [Member]
Other Securities [Abstract]
Amortized cost	8,768	9,896
Fair value	8,768	9,896
Federal Reserve Bank Common Stock [Member]
Other Securities [Abstract]
Amortized cost	30,690	30,690
Fair value	30,690	30,690
Certificates of Deposit [Member]
Other Securities [Abstract]
Amortized cost	0	3,865
Fair value	0	3,865
Other Equity Securities [Member]
Other Securities [Abstract]
Amortized cost	4,969	5,840
Gross unrealized gains	750	0
Fair value	$ 5,719	$ 5,840

INVESTMENT SECURITIES, Investme

INVESTMENT SECURITIES, Investment Securities in a Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2018USD ($)Position	Dec. 31, 2017USD ($)Position
Available-for-Sale Securities in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	169	249
12 months or longer | Position	384	56
Total | Position	553	305
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 576,527	$ 991,521
12 months or longer	1,584,618	75,713
Total	2,161,145	1,067,234
Available-for-Sale Securities, in Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	1,156	7,231
12 months or longer	25,412	2,330
Total	$ 26,568	$ 9,561
Equity and Other Securities, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	1
12 months or longer | Position	0
Total | Position	1
Equity and Other Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 82
12 months or longer	0
Total	82
Equity and Other Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	19
12 months or longer	0
Total	$ 19
U.S. Treasury and Agency Securities [Member]
Available-for-Sale Securities in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	7	44
12 months or longer | Position	64	0
Total | Position	71	44
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 473,082	$ 699,709
12 months or longer	1,213,276	0
Total	1,686,358	699,709
Available-for-Sale Securities, in Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	682	4,838
12 months or longer	14,229	0
Total	$ 14,911	$ 4,838
Obligations of State and Political Subdivisions [Member]
Available-for-Sale Securities in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	118	45
12 months or longer | Position	97	0
Total | Position	215	45
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 55,671	$ 23,432
12 months or longer	51,753	0
Total	107,424	23,432
Available-for-Sale Securities, in Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	216	57
12 months or longer	833	0
Total	$ 1,049	$ 57
Government Agency Mortgage-Backed Securities [Member]
Available-for-Sale Securities in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	43	120
12 months or longer | Position	181	55
Total | Position	224	175
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 47,708	$ 185,716
12 months or longer	253,931	75,712
Total	301,639	261,428
Available-for-Sale Securities, in Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	258	1,433
12 months or longer	9,025	2,330
Total	$ 9,283	$ 3,763
Corporate Debt Securities [Member]
Available-for-Sale Securities in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	0	1
12 months or longer | Position	1	0
Total | Position	1	1
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 2,623
12 months or longer	2,546	0
Total	2,546	2,623
Available-for-Sale Securities, in Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	0	25
12 months or longer	42	0
Total	$ 42	$ 25
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-Sale Securities in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	1	39
12 months or longer | Position	41	1
Total | Position	42	40
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 66	$ 80,041
12 months or longer	63,112	1
Total	63,178	80,042
Available-for-Sale Securities, in Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	0	878
12 months or longer	1,283	0
Total	$ 1,283	$ 878
Equity Securities, at Fair Value [Member]
Equity and Other Securities, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	1
12 months or longer | Position	0
Total | Position	1
Equity and Other Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 82
12 months or longer	0
Total	82
Equity and Other Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	19
12 months or longer	0
Total	$ 19

INVESTMENT SECURITIES, Amortize

INVESTMENT SECURITIES, Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Due in one year or less	$ 58,214
Due after one through five years	2,126,742
Due after five years through ten years	158,282
Due after ten years	149,464
Subtotal	2,492,702
Amortized cost	2,952,278
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Due in one year or less	58,128
Due after one through five years	2,115,304
Due after five years through ten years	160,694
Due after ten years	151,327
Subtotal	2,485,453
Fair value	2,936,049
Government Agency Mortgage-Backed Securities [Member]
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	390,234
Amortized cost	390,234	$ 358,180
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Without single maturity date	382,477
Fair value	382,477	357,538
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	69,342
Amortized cost	69,342	88,097
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Without single maturity date	68,119
Fair value	68,119	87,374
U.S. Treasury Securities [Member]
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Amortized cost	2,036,474	2,043,023
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Fair value	$ 2,023,753	$ 2,054,071

INVESTMENT SECURITIES, Invest_2

INVESTMENT SECURITIES, Investment Securities Pledged as Collateral (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pledged Financial Instruments, Not Separately Reported, Securities, by Type of Security [Abstract]
Investment securities pledged to collateralize certain deposits and borrowings	$ 1,447	$ 1,530
U.S. Treasury Securities [Member] | Securities Sold under Agreements to Repurchase [Member]
Pledged Financial Instruments, Not Separately Reported, Securities, by Type of Security [Abstract]
Investment securities pledged to collateralize certain deposits and borrowings	$ 492.4	$ 473.2

LOANS, Loan Summary (Details)

LOANS, Loan Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 6,281,121	$ 6,256,757
Allowance for loan losses	(49,284)	(47,583)	$ (47,233)	$ (45,401)
Net loans	6,231,837	6,209,174
Net deferred loan origination costs	28,400	25,300
Loans receivable, related parties [Roll Forward]
Balance at beginning of year	22,344	10,950
New loans	2,600	16,617
Payments	(4,283)	(5,223)
Balance at end of year	20,661	22,344
Business Lending [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 2,396,977	2,424,223
Consumer Mortgage [Member] | Minimum [Member]
Loans receivable, net [Abstract]
Typical contract term	10 years
Consumer Mortgage [Member] | Maximum [Member]
Loans receivable, net [Abstract]
Typical contract term	30 years
Home Equity [Member] | Maximum [Member]
Loans receivable, net [Abstract]
Typical contract term	30 years
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 2,235,408	2,220,298
Allowance for loan losses	(10,124)	(10,465)	(10,094)	(10,198)
Commercial Portfolio Segment [Member] | Business Lending [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	2,396,977	2,424,223
Allowance for loan losses	(18,522)	(17,257)	(17,220)	(15,749)
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	1,083,207	1,011,978
Allowance for loan losses	(14,366)	(13,468)	(13,782)	(12,422)
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	178,820	179,929
Allowance for loan losses	(3,095)	(3,039)	(2,979)	(2,997)
Consumer Portfolio Segment [Member] | Home Equity [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	386,709	420,329
Allowance for loan losses	$ (2,144)	$ (2,107)	$ (2,399)	$ (2,666)

LOANS, Acquired Loans (Details)

LOANS, Acquired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Credit impaired acquired loans [Abstract]
Outstanding principal balance	$ 6,936	$ 13,242
Carrying amount	5,446	10,115
Credit impaired acquired loans, total balance due	7,000	13,400
Non-impaired acquired loans [Abstract]
Outstanding principal balance	1,271,584	1,658,780
Carrying amount	1,247,691	1,626,979
Total acquired loans [Abstract]
Outstanding principal balance	1,278,520	1,672,022
Carrying amount	1,253,137	1,637,094
Accretable discount related to acquired loans [Roll forward]
Balance at beginning of year	976	498
Merchants acquisition	0	793
Accretion recognized	(783)	(905)
Net reclassification between accretable and non-accretable	244	590
Balance at end of year	$ 437	$ 976

LOANS, Credit Quality By Past D

LOANS, Credit Quality By Past Due Status (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Aged analysis of the company's loans [Abstract]
Total loans		$ 6,281,121	$ 6,256,757
Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		2,106	2,508
Nonaccrual		16,182	16,020
Total past due		53,387	51,563
Current		4,974,597	4,568,100
Total loans		5,027,984	4,619,663
Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		35,099	33,035
Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		349	204
Nonaccrual		6,362	8,720
Total past due		9,332	17,167
Acquired impaired	[1]	5,446	10,115
Current		1,238,359	1,609,812
Total loans		1,253,137	1,637,094
Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		2,621	8,243
Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		2,396,977	2,424,223
Business Lending [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,618,827	1,376,599
Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		778,150	1,047,624
Consumer Mortgage [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,848,450	1,754,609
Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		386,958	465,689
Consumer Indirect [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,072,392	991,836
Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		10,815	20,142
Consumer Direct [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		175,774	174,479
Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		3,046	5,450
Home Equity [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		312,541	322,140
Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		74,168	98,189
Commercial Portfolio Segment [Member] | Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		2,396,977	2,424,223
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		179	571
Nonaccrual		4,872	3,944
Total past due		10,312	6,798
Current		1,608,515	1,369,801
Total loans		1,618,827	1,376,599
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		5,261	2,283
Commercial Portfolio Segment [Member] | Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		0	0
Nonaccrual		3,498	4,328
Total past due		4,472	8,989
Acquired impaired	[1]	5,446	10,115
Current		768,232	1,028,520
Total loans		778,150	1,047,624
Commercial Portfolio Segment [Member] | Business Lending [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		974	4,661
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Aged analysis of the company's loans [Abstract]
Total loans		2,235,408	2,220,298
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		1,393	1,500
Nonaccrual		9,872	10,722
Total past due		23,733	25,786
Current		1,824,717	1,728,823
Total loans		1,848,450	1,754,609
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		12,468	13,564
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		232	26
Nonaccrual		2,390	3,066
Total past due		3,463	5,695
Acquired impaired	[1]	0	0
Current		383,495	459,994
Total loans		386,958	465,689
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		841	2,603
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,083,207	1,011,978
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		258	295
Nonaccrual		0	0
Total past due		14,867	14,492
Current		1,057,525	977,344
Total loans		1,072,392	991,836
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		14,609	14,197
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		34	8
Nonaccrual		0	0
Total past due		112	253
Acquired impaired	[1]	0	0
Current		10,703	19,889
Total loans		10,815	20,142
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		78	245
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Aged analysis of the company's loans [Abstract]
Total loans		178,820	179,929
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		48	48
Nonaccrual		0	0
Total past due		1,826	1,923
Current		173,948	172,556
Total loans		175,774	174,479
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,778	1,875
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		4	0
Nonaccrual		0	0
Total past due		119	100
Acquired impaired	[1]	0	0
Current		2,927	5,350
Total loans		3,046	5,450
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		115	100
Consumer Portfolio Segment [Member] | Home Equity [Member]
Aged analysis of the company's loans [Abstract]
Total loans		386,709	420,329
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		228	94
Nonaccrual		1,438	1,354
Total past due		2,649	2,564
Current		309,892	319,576
Total loans		312,541	322,140
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		983	1,116
Consumer Portfolio Segment [Member] | Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		79	170
Nonaccrual		474	1,326
Total past due		1,166	2,130
Acquired impaired	[1]	0	0
Current		73,002	96,059
Total loans		74,168	98,189
Consumer Portfolio Segment [Member] | Home Equity [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		$ 613	$ 634
[1]	Acquired impaired loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cashflows, is being recognized on all acquired impaired loans.

LOANS, Amount of Business Lendi

LOANS, Amount of Business Lending Loans by Credit Quality Category (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Business Lending Loans by Credit Quality Category [Abstract]
Loans	$ 6,281,121	$ 6,256,757
Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	5,027,984	4,619,663
Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,253,137	1,637,094
Business Lending [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	2,396,977	2,424,223
Business Lending [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,618,827	1,376,599
Business Lending [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	778,150	1,047,624
Business Lending [Member] | Pass [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	2,141,830	2,134,137
Business Lending [Member] | Pass [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,439,337	1,170,156
Business Lending [Member] | Pass [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	702,493	963,981
Business Lending [Member] | Special Mention [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	145,172	166,397
Business Lending [Member] | Special Mention [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	105,065	129,076
Business Lending [Member] | Special Mention [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	40,107	37,321
Business Lending [Member] | Classified [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	102,950	111,995
Business Lending [Member] | Classified [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	74,425	77,367
Business Lending [Member] | Classified [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	28,525	34,628
Business Lending [Member] | Doubtful [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,579	1,579
Business Lending [Member] | Doubtful [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	0	0
Business Lending [Member] | Doubtful [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,579	1,579
Business Lending [Member] | Acquired Impaired [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	5,446	10,115
Business Lending [Member] | Acquired Impaired [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	0	0
Business Lending [Member] | Acquired Impaired [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	5,446	10,115
All Other Loans [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	3,409,157	3,243,064
All Other Loans [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	474,987	589,470
All Other Loans [Member] | Performing [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	3,395,920	3,229,051
All Other Loans [Member] | Performing [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	471,774	584,874
All Other Loans [Member] | Nonperforming [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	13,237	14,013
All Other Loans [Member] | Nonperforming [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	3,213	4,596
Consumer Mortgage [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,848,450	1,754,609
Consumer Mortgage [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	386,958	465,689
Consumer Mortgage [Member] | Performing [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,837,185	1,742,387
Consumer Mortgage [Member] | Performing [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	384,336	462,597
Consumer Mortgage [Member] | Nonperforming [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	11,265	12,222
Consumer Mortgage [Member] | Nonperforming [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	2,622	3,092
Consumer Indirect [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,072,392	991,836
Consumer Indirect [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	10,815	20,142
Consumer Indirect [Member] | Performing [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,072,134	991,541
Consumer Indirect [Member] | Performing [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	10,781	20,134
Consumer Indirect [Member] | Nonperforming [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	258	295
Consumer Indirect [Member] | Nonperforming [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	34	8
Consumer Direct [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	175,774	174,479
Consumer Direct [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	3,046	5,450
Consumer Direct [Member] | Performing [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	175,726	174,431
Consumer Direct [Member] | Performing [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	3,042	5,450
Consumer Direct [Member] | Nonperforming [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	48	48
Consumer Direct [Member] | Nonperforming [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	4	0
Home Equity [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	312,541	322,140
Home Equity [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	74,168	98,189
Home Equity [Member] | Performing [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	310,875	320,692
Home Equity [Member] | Performing [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	73,615	96,693
Home Equity [Member] | Nonperforming [Member] | Legacy Loan [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	1,666	1,448
Home Equity [Member] | Nonperforming [Member] | Acquired Loans [Member]
Business Lending Loans by Credit Quality Category [Abstract]
Loans	$ 553	$ 1,496

LOANS, Summary of Impaired Loan

LOANS, Summary of Impaired Loans, Excluding Purchased Impaired (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Impaired loans [Abstract]
Loans with allowance allocation	$ 3,956	$ 5,125
Loans without allowance allocation	2,230	884
Carrying balance	6,186	6,009
Contractual balance	12,078	9,165
Specifically allocated allowance	956	804
Average impaired loans	7,618	9,517
Interest income recognized	$ 0	$ 0

LOANS, Troubled Debt Restructur

LOANS, Troubled Debt Restructuring (TDR) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)Loan	Dec. 31, 2017USD ($)Loan
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	218	226
TDRs, amount	$ 5,225	$ 6,135
Loans modified in TDR during the year, number | Loan	52	74
Loans modified in TDR during the year, amount	$ 1,035	$ 2,268
Maximum [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
Threshold balance of TDR loans collectively included in general loan loss allocation and qualitative review	$ 500
Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	62	72
TDRs, amount	$ 2,388	$ 2,728
Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	156	154
TDRs, amount	$ 3,137	$ 3,407
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	92	95
TDRs, amount	$ 3,755	$ 4,015
Loans modified in TDR during the year, number | Loan	9	23
Loans modified in TDR during the year, amount	$ 470	$ 1,254
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	46	51
TDRs, amount	$ 1,986	$ 2,265
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	46	44
TDRs, amount	$ 1,769	$ 1,750
Commercial Portfolio Segment [Member] | Minimum [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
Threshold balance of loan individually evaluated for impairment	$ 500
Commercial Portfolio Segment [Member] | Business Lending [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	6	15
TDRs, amount	$ 327	$ 719
Loans modified in TDR during the year, number | Loan	2	8
Loans modified in TDR during the year, amount	$ 103	$ 412
Commercial Portfolio Segment [Member] | Business Lending [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	4	8
TDRs, amount	$ 162	$ 218
Commercial Portfolio Segment [Member] | Business Lending [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	2	7
TDRs, amount	$ 165	$ 501
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	77	71
TDRs, amount	$ 857	$ 883
Loans modified in TDR during the year, number | Loan	32	33
Loans modified in TDR during the year, amount	$ 320	$ 490
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	0	0
TDRs, amount	$ 0	$ 0
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	77	71
TDRs, amount	$ 857	$ 883
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	22	25
TDRs, amount	$ 71	$ 69
Loans modified in TDR during the year, number | Loan	6	6
Loans modified in TDR during the year, amount	$ 24	$ 17
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	0	0
TDRs, amount	$ 0	$ 0
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	22	25
TDRs, amount	$ 71	$ 69
Consumer Portfolio Segment [Member] | Home Equity [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	21	20
TDRs, amount	$ 515	$ 449
Loans modified in TDR during the year, number | Loan	3	4
Loans modified in TDR during the year, amount	$ 118	$ 95
Consumer Portfolio Segment [Member] | Home Equity [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	12	13
TDRs, amount	$ 240	$ 245
Consumer Portfolio Segment [Member] | Home Equity [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	9	7
TDRs, amount	$ 275	$ 204

LOANS, Allowance for Loan Losse

LOANS, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for loan losses [Roll Forward]
Balance, beginning of period	$ 47,583	$ 47,233	$ 45,401
Charge-offs	(15,486)	(16,757)	(12,183)
Recoveries	6,350	6,123	5,939
Provision	10,837	10,984	8,076
Balance, end of period	49,284	47,583	47,233
Acquired Impaired [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	147	108	168
Charge-offs	(381)	(270)	(97)
Recoveries	0	0	0
Provision	267	309	37
Balance, end of period	33	147	108
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	10,465	10,094	10,198
Charge-offs	(836)	(707)	(647)
Recoveries	136	50	115
Provision	359	1,028	428
Balance, end of period	10,124	10,465	10,094
Commercial Portfolio Segment [Member] | Business Lending [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	17,257	17,220	15,749
Charge-offs	(3,566)	(4,959)	(1,872)
Recoveries	485	656	616
Provision	4,346	4,340	2,727
Balance, end of period	18,522	17,257	17,220
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	13,468	13,782	12,422
Charge-offs	(8,382)	(8,456)	(7,643)
Recoveries	4,874	4,516	4,168
Provision	4,406	3,626	4,835
Balance, end of period	14,366	13,468	13,782
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	3,039	2,979	2,997
Charge-offs	(1,777)	(2,081)	(1,706)
Recoveries	807	849	901
Provision	1,026	1,292	787
Balance, end of period	3,095	3,039	2,979
Consumer Portfolio Segment [Member] | Home Equity [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	2,107	2,399	2,666
Charge-offs	(544)	(284)	(218)
Recoveries	48	52	139
Provision	533	(60)	(188)
Balance, end of period	2,144	2,107	2,399
Unallocated Financing Receivables [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	1,100	651	1,201
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(100)	449	(550)
Balance, end of period	$ 1,000	$ 1,100	$ 651

PREMISES AND EQUIPMENT (Details

PREMISES AND EQUIPMENT (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net [Abstract]
Premises and equipment, gross	$ 247,549	$ 241,575
Accumulated depreciation	(127,561)	(118,182)
Premises and equipment, net	119,988	123,393
Land and Land Improvements [Member]
Property, Plant and Equipment, Net [Abstract]
Premises and equipment, gross	24,340	23,869
Bank Premises [Member]
Property, Plant and Equipment, Net [Abstract]
Premises and equipment, gross	133,259	131,647
Equipment and Construction in Progress [Member]
Property, Plant and Equipment, Net [Abstract]
Premises and equipment, gross	$ 89,950	$ 86,059

GOODWILL AND IDENTIFIABLE INT_3

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Identifiable Intangible Assets [Abstract]
Gross carrying amount	$ 150,518	$ 149,437
Accumulated amortization	(76,672)	(58,779)
Net carrying amount	73,846	90,658
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
2,019	15,296
2,020	12,722
2,021	10,853
2,022	9,317
2,023	7,814
Thereafter	17,844
Net carrying amount	73,846	90,658
Components of goodwill [Abstract]
Goodwill, beginning of period	739,254	469,966
Goodwill, activity		269,288
Goodwill, activity	(927)
Goodwill, end of period	738,327	739,254
Accumulated impairment, beginning of period	(4,824)	(4,824)
Accumulated impairment, activity	0	0
Accumulated impairment, end of period	(4,824)	(4,824)
Goodwill, net, beginning of period	734,430	465,142
Goodwill, net, activity	(927)	269,288
Goodwill, net, end of period	733,503	734,430
Servicing Asset at Fair Value, Amount [Roll Forward]
Carrying value before valuation allowance at beginning of period	1,358	1,435
Additions	228	358
Merchants acquisition	0	64
Amortization	(449)	(499)
Carrying value before valuation allowance at end of period	1,137	1,358
Valuation allowance balance at beginning of period	0	0
Impairment charges	0	0
Impairment recoveries	0	0
Valuation allowance balance at end of period	0	0
Net carrying value at end of period	1,137	1,358
Fair value of MSRs at end of period	2,397	2,473
Principal balance of loans sold during the year	18,228	32,937
Principal balance of loans serviced for others	333,862	358,518
Custodial escrow balances maintained in connection with loans serviced for others	$ 4,982	$ 5,363
Key economic assumptions used to estimate the value of the MSRs [Abstract]
Weighted-average contractual life	21 years 4 months 24 days	21 years 3 months 18 days
Weighted-average constant prepayment rate (CPR)	9.30%	11.10%
Weighted-average discount rate	3.60%	3.30%
Core Deposit Intangibles [Member]
Identifiable Intangible Assets [Abstract]
Gross carrying amount	$ 62,902	$ 62,902
Accumulated amortization	(44,306)	(37,877)
Net carrying amount	18,596	25,025
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Net carrying amount	18,596	25,025
Other Intangibles [Member]
Identifiable Intangible Assets [Abstract]
Gross carrying amount	87,616	86,535
Accumulated amortization	(32,366)	(20,902)
Net carrying amount	55,250	65,633
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Net carrying amount	$ 55,250	$ 65,633

DEPOSITS (Details)

DEPOSITS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
DEPOSITS [Abstract]
Noninterest checking	$ 2,312,816	$ 2,293,057
Interest checking	1,920,545	1,830,914
Savings	1,448,208	1,421,512
Money market	1,901,262	2,124,633
Time	739,540	774,304
Total deposits	$ 8,322,371	$ 8,444,420

DEPOSITS, Interest on Deposits

DEPOSITS, Interest on Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest on Deposits [Abstract]
Interest on interest checking	$ 1,796	$ 1,032	$ 504
Interest on savings	858	841	863
Interest on money market	3,638	2,981	2,754
Interest on time	4,366	3,177	3,204
Total interest on deposits	$ 10,658	$ 8,031	$ 7,325

DEPOSITS, Maturities of Time De

DEPOSITS, Maturities of Time Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Maturities of time deposits [Abstract]
2,019	$ 448,708
2,020	94,585
2,021	123,021
2,022	31,786
2,023	41,223
Thereafter	217
Total	739,540	$ 774,304
Maturities of time deposits, accounts $250,000 or greater [Abstract]
2,019	40,960
2,020	4,886
2,021	20,100
2,022	587
2,023	3,087
Thereafter	0
Total	$ 69,620

BORROWINGS, Outstanding Borrowi

BORROWINGS, Outstanding Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
BORROWINGS [Abstract]
FHLB overnight advance	$ 54,400	$ 24,000
Subordinated debt held by unconsolidated subsidiary trusts, net of discount of $0 and $332, respectively	97,939	122,814
Securities sold under agreement to repurchase, short term	259,367	337,011
FHLB Long term advances	1,976	2,071
Total borrowings	413,682	485,896
Subordinated debt held by unconsolidated subsidiary trust, discount	$ 0	$ 332

BORROWINGS, Contractual Maturit

BORROWINGS, Contractual Maturity on Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instruments [Abstract]
Carrying value	$ 413,682	$ 485,896
Weighted-average rate	1.84%
Weighted-average interest rate on borrowings during period	1.72%	1.51%
January 2, 2019 [Member]
Debt Instruments [Abstract]
Carrying value	$ 313,767
Weighted-average rate	1.01%
July 3, 2023 [Member]
Debt Instruments [Abstract]
Carrying value	$ 575
Weighted-average rate	2.25%
October 23, 2023 [Member]
Debt Instruments [Abstract]
Carrying value	$ 484
Weighted-average rate	1.50%
October 1, 2025 [Member]
Debt Instruments [Abstract]
Carrying value	$ 315
Weighted-average rate	1.50%
March 1, 2029 [Member]
Debt Instruments [Abstract]
Carrying value	$ 602
Weighted-average rate	2.50%
December 15, 2034 [Member]
Debt Instruments [Abstract]
Carrying value	$ 20,619
Weighted-average rate	4.74%
December 15, 2036 [Member]
Debt Instruments [Abstract]
Carrying value	$ 77,320
Weighted-average rate	4.44%

BORROWINGS, Preferred Securitie

BORROWINGS, Preferred Securities (Details) $ in Millions	Jul. 31, 2018USD ($)	Dec. 31, 2018USD ($)Trust
Mandatorily Redeemable Preferred Securities [Abstract]
Number of unconsolidated subsidiary business trusts owned | Trust		2
Business Trusts [Member]
Mandatorily Redeemable Preferred Securities [Abstract]
Number of unconsolidated subsidiary business trusts owned | Trust		2
Percent ownership of unconsolidated subsidiary trusts		100.00%
Community Statutory Trust III [Member]
Mandatorily Redeemable Preferred Securities [Abstract]
Redemption of debentures and associated preferred securities	$ 25.2
Preferred Debt [Member] | Community Capital Trust IV [Member]
Terms of preferred securities for each trust [Abstract]
Issuance date		Dec. 8, 2006
Par amount		$ 75
Variable interest rate basis		3 month LIBOR
Effective interest rate		4.44%
Maturity date		Dec. 15, 2036
Call price		Par
Preferred Debt [Member] | Community Capital Trust IV [Member] | LIBOR [Member]
Terms of preferred securities for each trust [Abstract]
Term of variable rate		3 months
Variable interest rate, basis spread		1.65%
Preferred Debt [Member] | MBVT Statutory Trust I [Member]
Terms of preferred securities for each trust [Abstract]
Issuance date		Dec. 15, 2004
Par amount		$ 20.6
Variable interest rate basis		3 month LIBOR
Effective interest rate		4.74%
Maturity date		Dec. 15, 2034
Call price		Par
Preferred Debt [Member] | MBVT Statutory Trust I [Member] | LIBOR [Member]
Terms of preferred securities for each trust [Abstract]
Term of variable rate		3 months
Variable interest rate, basis spread		1.95%

INCOME TAXES, Provision for Inc

INCOME TAXES, Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current [Abstract]
Federal	$ 32,504	$ 31,152	$ 32,829
State and other	9,180	6,788	4,890
Deferred [Abstract]
Federal	2,122	(28,146)	11,444
State and other	541	(546)	1,622
Provision for income taxes	$ 44,347	$ 9,248	$ 50,785

INCOME TAXES, Components of Net

INCOME TAXES, Components of Net Deferred Tax Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Components of net deferred tax liability [Abstract]
Allowance for loan losses	$ 12,131	$ 11,675
Employee benefits	4,479	4,216
Other, net	541	0
Deferred tax asset	17,151	15,891
Investment securities	14,451	22,690
Tax-deductible goodwill	39,540	39,154
Loan origination costs	6,851	6,109
Depreciation	3,098	2,372
Mortgage servicing rights	277	330
Pension	11,078	13,228
Other, net	0	542
Deferred tax liability	75,295	84,425
Net deferred tax liability	$ (58,144)	$ (68,534)

INCOME TAXES, Effective Tax Rat

INCOME TAXES, Effective Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective tax rate reconciliation [Abstract]
Federal statutory income tax rate	21.00%	35.00%	35.00%
Increase (reduction) in taxes resulting from [Abstract]
Tax-exempt interest	(1.60%)	(3.80%)	(4.00%)
State income taxes, net of federal benefit	3.40%	2.50%	2.70%
Stock-based compensation	(0.90%)	(2.00%)	(0.00%)
Federal deferred tax revaluation adjustment	0.00%	(23.70%)	0.00%
Federal tax credits	(1.40%)	(1.50%)	(0.00%)
Other, net	0.30%	(0.70%)	(0.90%)
Effective income tax rate	20.80%	5.80%	32.80%

INCOME TAXES, Unrecognized Tax

INCOME TAXES, Unrecognized Tax Benefits and Tax Cuts and Jobs Act (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrecognized tax benefits [Roll forward]
Unrecognized tax benefits at beginning of year	$ 24	$ 92	$ 127
Changes related to [Abstract]
Lapse of statutes of limitations	(24)	(68)	(35)
Unrecognized tax benefits at end of year	0	$ 24	$ 92
Unrecognized tax benefits that would impact effective tax rate, if recognized	$ 0
Federal corporate tax rate	21.00%	35.00%	35.00%
Marginal tax rate	24.29%	37.70%
Deferred tax benefit from write-down of net deferred tax liabilities	$ (38,000)

LIMITS ON DIVIDENDS AND OTHER_2

LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES (Details) $ in Millions	Dec. 31, 2018USD ($)
LIMITS ON DIVIDENDS AND OTHER REVENUE SOURCES [Abstract]
Undivided profits legally available for the payments of dividends	$ 101.2
Percentage of Bank's capital and surplus that can be transferred to Company, maximum	10.00%
Aggregate percentage of Bank's capital and surplus that can be transferred to Company, maximum	20.00%

BENEFIT PLANS, Funded Status an

BENEFIT PLANS, Funded Status and Amounts Recognized in Balance Sheets and AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2009	Jun. 01, 2018	May 12, 2017
Amounts recognized in accumulated other comprehensive loss/(income) ("AOCI") [Abstract]
AOCI at year end	$ 32,837	$ 21,633	$ 17,961
Accumulated other comprehensive income (loss), negative postretirement medical plan amendment, arising during period, net of tax				$ 3,500
Stock Balance Plan [Member] | Nonemployee Directors [Member]
Pension Plan [Abstract]
Defined Benefit Plan, Funding Status [Extensible List]	us-gaap:UnfundedPlanMember
Change in benefit obligation [Roll Forward]
Benefit obligation at the beginning of year	$ 100
Benefit obligation at end of year	100	100
Pension Benefits [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at the beginning of year	147,450	127,084
Service cost	4,561	4,181	4,106
Interest cost	5,676	5,717	5,624
Plan amendment / acquisition	883	11,646
Participant contributions	0	0
Deferred actuarial (gain)/loss	(4,177)	8,978
Benefits paid	(10,182)	(10,156)
Benefit obligation at end of year	144,211	147,450	127,084
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	217,107	180,400
Actual return of plan assets	(3,858)	22,954
Participant contributions	0	0
Employer contributions	605	9,839
Plan acquisition	0	14,070
Benefits paid	(10,182)	(10,156)
Fair value of plan assets at end of year	203,672	217,107	$ 180,400
Over/(Under) funded status at year end	59,461	69,657
Amounts recognized in the consolidated statement of condition [Abstract]
Other assets	72,659	81,000
Other liabilities	(13,198)	(11,343)
Amounts recognized in accumulated other comprehensive loss/(income) ("AOCI") [Abstract]
Net loss	39,410	26,935
Net prior service cost (credit)	4,939	2,944
Pre-tax AOCI	44,349	29,879
Taxes	(10,870)	(7,340)
AOCI at year end	$ 33,479	$ 22,539
Unamortized actuarial gain						$ 1,900
Discount rate	4.50%	4.00%	4.50%			4.40%
Pension Benefits [Member] | Restoration Plan [Member] | Nonqualified Plan [Member] | us-gaap_UnfundedPlanMember
Amounts recognized in accumulated other comprehensive loss/(income) ("AOCI") [Abstract]
Initial projected benefit obligation					$ 800
Post-retirement Benefits [Member]
Change in benefit obligation [Roll Forward]
Benefit obligation at the beginning of year	$ 1,785	$ 1,806
Service cost	0	0	$ 0
Interest cost	69	76	82
Plan amendment / acquisition	0	0
Participant contributions	479	467
Deferred actuarial (gain)/loss	191	245
Benefits paid	(867)	(809)
Benefit obligation at end of year	1,657	1,785	1,806
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return of plan assets	0	0
Participant contributions	479	467
Employer contributions	388	342
Plan acquisition	0	0
Benefits paid	(867)	(809)
Fair value of plan assets at end of year	0	0	$ 0
Over/(Under) funded status at year end	(1,657)	(1,785)
Amounts recognized in the consolidated statement of condition [Abstract]
Other assets	0	0
Other liabilities	(1,657)	(1,785)
Amounts recognized in accumulated other comprehensive loss/(income) ("AOCI") [Abstract]
Net loss	592	420
Net prior service cost (credit)	(1,444)	(1,622)
Pre-tax AOCI	(852)	(1,202)
Taxes	210	296
AOCI at year end	$ (642)	$ (906)
Discount rate	4.45%	4.00%
Supplemental Pension Plans [Member] | Key Executives [Member]
Pension Plan [Abstract]
Defined Benefit Plan, Funding Status [Extensible List]	us-gaap:UnfundedPlanMember
Change in benefit obligation [Roll Forward]
Benefit obligation at the beginning of year	$ 11,300
Benefit obligation at end of year	13,200	$ 11,300
Amounts recognized in accumulated other comprehensive loss/(income) ("AOCI") [Abstract]
Benefit obligation for defined benefit pension plan prior to plan revaluation	$ 131,000	$ 136,100

BENEFIT PLANS, Amounts Recogniz

BENEFIT PLANS, Amounts Recognized in AOCI, Net of Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amounts recognized in AOCI, net of tax [Abstract]
Total	$ 11,204	$ (168)	$ (3,322)
Pension Benefits [Member]
Amounts recognized in AOCI, net of tax [Abstract]
Prior service cost/(credit)	1,509	424
Net (gain) loss	9,431	(851)
Total	10,940	(427)
Post-retirement Benefits [Member]
Amounts recognized in AOCI, net of tax [Abstract]
Prior service cost/(credit)	135	111
Net (gain) loss	129	148
Total	$ 264	$ 259

BENEFIT PLANS, Costs That Will

BENEFIT PLANS, Costs That Will Be Amortized from AOCI in Next Fiscal Year (Details) $ in Thousands	Dec. 31, 2018USD ($)
Pension Benefits [Member]
Costs that will be amortized from accumulated other comprehensive (income) loss in net periodic (income) cost in next fiscal year [Abstract]
Prior service credit	$ 64
Net loss	2,376
Total	2,440
Post-retirement Benefits [Member]
Costs that will be amortized from accumulated other comprehensive (income) loss in net periodic (income) cost in next fiscal year [Abstract]
Prior service credit	(179)
Net loss	36
Total	$ (143)

BENEFIT PLANS, Weighted-average

BENEFIT PLANS, Weighted-average Assumptions Used to Determine Benefit Obligations (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	May 12, 2017	Dec. 31, 2016
Pension Benefits [Member]
Weighed average assumption used in calculating benefit obligations [Abstract]
Discount rate	4.50%	4.00%	4.40%	4.50%
Expected return on plan assets	7.00%	7.00%
Rate of compensation increase	3.50%	3.50%
Post-retirement Benefits [Member]
Weighed average assumption used in calculating benefit obligations [Abstract]
Discount rate	4.45%	4.00%

BENEFIT PLANS, Net Periodic Ben

BENEFIT PLANS, Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Prior service costs [Abstract]
Maximum percentage of net gain or loss over the greater of the projected benefit obligation or the market-related value of assets without requiring amortization	10.00%
Pension Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	$ 4,561	$ 4,181	$ 4,106
Interest cost	5,676	5,717	5,624
Expected return on plan assets	(14,820)	(13,354)	(11,842)
Plan amendment	13	0	20
Amortization of unrecognized net loss/(gain)	1,193	767	1,508
Amortization of prior service cost	(293)	55	43
Net periodic (benefit)	(3,670)	(2,634)	(541)
Post-retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	0	0	0
Interest cost	69	76	82
Expected return on plan assets	0	0	0
Plan amendment	0	0	0
Amortization of unrecognized net loss/(gain)	21	8	(5)
Amortization of prior service cost	(179)	(179)	(179)
Net periodic (benefit)	$ (89)	$ (95)	$ (102)

BENEFIT PLANS, Weighted-avera_2

BENEFIT PLANS, Weighted-average Assumptions Used to Determine Net Periodic Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.00%	4.40%	4.70%
Expected return on plan assets	7.00%	7.00%	7.00%
Rate of compensation increase	3.50%	3.50%	3.50%
Post-retirement Benefits [Member]
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	4.00%	4.40%	4.70%

BENEFIT PLANS, Estimated Future

BENEFIT PLANS, Estimated Future Benefit Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
Pension Benefits [Member]
Estimated Future Benefit Payments [Abstract]
2,019	$ 9,250
2,020	9,547
2,021	10,142
2,022	10,607
2,023	11,092
2024-2028	59,372
Post-retirement Benefits [Member]
Estimated Future Benefit Payments [Abstract]
2,019	175
2,020	139
2,021	136
2,022	133
2,023	130
2024-2028	$ 598

BENEFIT PLANS, Target Plan Asse

BENEFIT PLANS, Target Plan Assets Allocation (Details)	Dec. 31, 2018
Equity Securities [Member]
Plan Assets [Abstract]
Target allocation percentage of assets	60.00%
Fixed Income Securities [Member]
Plan Assets [Abstract]
Target allocation percentage of assets	40.00%

BENEFIT PLANS, Fair Value of Pl

BENEFIT PLANS, Fair Value of Plan Assets by Assets Category (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Total [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[1]	$ 202,943	$ 216,476
Total [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[1]	191,507	196,336
Total [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[1]	11,436	20,140
Total [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[1]	0	0
Money Market Accounts / Cash Equivalents [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		4,856	10,381
Money Market Accounts / Cash Equivalents [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		4,856	0
Money Market Accounts / Cash Equivalents [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	10,381
Money Market Accounts / Cash Equivalents [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
Equity Securities [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		89,201	135,530
Equity Securities [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		89,201	135,530
Equity Securities [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
Equity Securities [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
U.S. Large-Cap [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		39,122	53,154
U.S. Large-Cap [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		39,122	53,154
U.S. Large-Cap [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
U.S. Large-Cap [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
U.S Mid/Small Cap [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		9,881	26,309
U.S Mid/Small Cap [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		9,881	26,309
U.S Mid/Small Cap [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
U.S Mid/Small Cap [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
CBU Stock [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		7,692	8,344
CBU Stock [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		7,692	8,344
CBU Stock [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
CBU Stock [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
International [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		32,506	47,723
International [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		32,506	47,723
International [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
International [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
Fixed Income Securities [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		94,553	59,190
Fixed Income Securities [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		83,183	49,504
Fixed Income Securities [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		11,370	9,686
Fixed Income Securities [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
Government Securities [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		75,787	23,615
Government Securities [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		64,417	13,929
Government Securities [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		11,370	9,686
Government Securities [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
Investment Grade Bonds [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		12,054	19,278
Investment Grade Bonds [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		12,054	19,278
Investment Grade Bonds [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
Investment Grade Bonds [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		0	0
High Yield [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[2]	6,712	16,297
High Yield [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[2]	6,712	16,297
High Yield [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[2]	0	0
High Yield [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[2]	0	0
Other Investments [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[3]	14,333	11,375
Other Investments [Member] | Quoted Prices in Active Markets For Identical Assets, Level 1 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[3]	14,267	11,302
Other Investments [Member] | Significant Observable Inputs, Level 2 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[3]	66	73
Other Investments [Member] | Significant Unobservable Inputs, Level 3 [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets	[3]	0	0
Dividends and Interest Receivable [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		700	600
Pension Benefits [Member]
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Fair value of plan assets		$ 203,672	$ 217,107	$ 180,400
[1]	Excludes dividends and interest receivable totaling $0.7 million and $0.6 million at December 31, 2018 and 2017, respectively.
[2]	This category is exchange-traded funds representing a diversified index of high yield corporate bonds.
[3]	This category is comprised of exchange-traded funds and mutual funds holding non-traditional investment classes including private equity funds and alternative exchange funds.

BENEFIT PLANS, 401(K) Employee

BENEFIT PLANS, 401(K) Employee Stock Ownership Plan (Details) - 401(k) Employee Stock Ownership Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plan [Abstract]
Percentage of first eligible compensation fully matched by employer	3.00%
Percentage of matching contribution in the form of common stock	100.00%
Percentage of the next eligible compensation matched at 50% by employer	3.00%
Percentage of matching contributions for the next eligible compensation in the form of company stock	50.00%
(Income)/expense recognized under plan	$ 5.9	$ 5.3	$ 4.3
Interest credit contribution expense recognized for 401(k) plan	$ 0.9	$ 0.8	$ 0.7
Minimum [Member]
Defined Contribution Plan [Abstract]
Contribution from eligible compensation	1.00%
Maximum [Member]
Defined Contribution Plan [Abstract]
Contribution from eligible compensation	90.00%

BENEFIT PLANS, Other Deferred C

BENEFIT PLANS, Other Deferred Compensation Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Compensation Arrangements [Abstract]
Liability recorded for compensation plan	$ 11,728	$ 13,328
Other Deferred Compensation Arrangements [Member]
Deferred Compensation Arrangements [Abstract]
Liability recorded for compensation plan	2,800	3,100
Expense recognized under plan	$ 80	$ 300	$ 30

BENEFIT PLANS, Deferred Compens

BENEFIT PLANS, Deferred Compensation Plans for Directors (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Compensation Arrangements [Abstract]
Liability accrued for compensation plan	$ 11,728	$ 13,328
Deferred Compensation Plans for Directors [Member] | Directors [Member]
Deferred Compensation Arrangements [Abstract]
Deferred compensation arrangement with individual, shares credited (in shares)	151,977	150,110
Liability accrued for compensation plan	$ 4,600	$ 4,200
Expense recognized under plan	$ 200	$ 200	$ 200

STOCK-BASED COMPENSATION PLANS,

STOCK-BASED COMPENSATION PLANS, Long-Term Incentive Program (Details) - shares	May 17, 2017	May 14, 2014	May 25, 2011	Dec. 31, 2018
Share-based Arrangements with Employees and Nonemployees [Abstract]
Shares of common stock authorized for stock-based compensation plan (in shares)				4,000,000
Additional shares of common stock authorized for stock-based compensation plan (in shares)	1,000,000	1,000,000	900,000
Number of shares available for grant (in shares)				1,500,000
Remaining Stock Options [Member]
Share-based Arrangements with Employees and Nonemployees [Abstract]
Term of options				10 years
Award vesting period				5 years
Director's Stock Balance Plan [Member] | Nonqualified Stock Option [Member]
Share-based Arrangements with Employees and Nonemployees [Abstract]
Term of options				1 year
Term of options in event of death				2 years

STOCK-BASED COMPENSATION PLAN_2

STOCK-BASED COMPENSATION PLANS, Activity in Long-Term Incentive Program (Details) - Stock Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Options, Outstanding [Roll Forward]
Outstanding, beginning of period (in shares)	1,708,296	1,755,992
Granted (in shares)	213,504	197,943
Exercised (in shares)	(268,004)	(238,499)
Forfeited (in shares)	(9,435)	(7,140)
Outstanding, end of period (in shares)	1,644,361	1,708,296
Exercisable, end of period (in shares)	1,010,795
Weighted-average exercise price of shares [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 34.57	$ 30.85
Granted (in dollars per share)	55.92	57.02
Exercised (in dollars per share)	27.94	25.72
Forfeited (in dollars per share)	45.54	37.47
Outstanding, end of period (in dollars per share)	38.36	$ 34.57
Exercisable, end of period (in dollars per share)	$ 32.66

STOCK-BASED COMPENSATION PLAN_3

STOCK-BASED COMPENSATION PLANS, Summary of Stock Options Outstanding (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares
Options [Abstract]
Options outstanding, shares (in shares) | shares	1,644,361
Options outstanding, weighted-average exercise price (in dollars per share)	$ 38.36
Options outstanding, weighted-average remaining life	5 years 10 months 24 days
Options exercisable, shares (in shares) | shares	1,010,795
Options exercisable, weighted-average exercise price (in dollars per share)	$ 32.66
Weighted-average remaining contractual term of outstanding stock options	5 years 10 months 24 days
Weighted-average remaining contractual term of outstanding and exercisable stock options	4 years 8 months 16 days
Aggregate intrinsic value of outstanding stock options | $	$ 32.8
Aggregate intrinsic value of exercisable stock options | $	$ 25.9
$0.00 - $18.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Exercise price range, lower range limit (in dollars per share)	$ 0
Exercise price range, upper range limit (in dollars per share)	$ 18
Options [Abstract]
Options outstanding, shares (in shares) | shares	10,978
Options outstanding, weighted-average exercise price (in dollars per share)	$ 17.82
Options outstanding, weighted-average remaining life	3 months 22 days
Options exercisable, shares (in shares) | shares	10,978
Options exercisable, weighted-average exercise price (in dollars per share)	$ 17.82
$18.001 - $28.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Exercise price range, lower range limit (in dollars per share)	18.001
Exercise price range, upper range limit (in dollars per share)	$ 28
Options [Abstract]
Options outstanding, shares (in shares) | shares	215,014
Options outstanding, weighted-average exercise price (in dollars per share)	$ 23.26
Options outstanding, weighted-average remaining life	2 years 8 months 1 day
Options exercisable, shares (in shares) | shares	215,014
Options exercisable, weighted-average exercise price (in dollars per share)	$ 23.26
$28.001 - $29.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Exercise price range, lower range limit (in dollars per share)	28.001
Exercise price range, upper range limit (in dollars per share)	$ 29
Options [Abstract]
Options outstanding, shares (in shares) | shares	142,691
Options outstanding, weighted-average exercise price (in dollars per share)	$ 28.78
Options outstanding, weighted-average remaining life	3 years 2 months 19 days
Options exercisable, shares (in shares) | shares	142,691
Options exercisable, weighted-average exercise price (in dollars per share)	$ 28.78
$29.001 - $30.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Exercise price range, lower range limit (in dollars per share)	29.001
Exercise price range, upper range limit (in dollars per share)	$ 30
Options [Abstract]
Options outstanding, shares (in shares) | shares	185,866
Options outstanding, weighted-average exercise price (in dollars per share)	$ 29.79
Options outstanding, weighted-average remaining life	4 years 2 months 16 days
Options exercisable, shares (in shares) | shares	185,866
Options exercisable, weighted-average exercise price (in dollars per share)	$ 29.79
$30.001 - $40.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Exercise price range, lower range limit (in dollars per share)	30.001
Exercise price range, upper range limit (in dollars per share)	$ 40
Options [Abstract]
Options outstanding, shares (in shares) | shares	686,103
Options outstanding, weighted-average exercise price (in dollars per share)	$ 37.09
Options outstanding, weighted-average remaining life	6 years 4 months 2 days
Options exercisable, shares (in shares) | shares	391,658
Options exercisable, weighted-average exercise price (in dollars per share)	$ 37.06
$40.001 - $60.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Exercise price range, lower range limit (in dollars per share)	40.001
Exercise price range, upper range limit (in dollars per share)	$ 60
Options [Abstract]
Options outstanding, shares (in shares) | shares	403,709
Options outstanding, weighted-average exercise price (in dollars per share)	$ 56.45
Options outstanding, weighted-average remaining life	8 years 8 months 23 days
Options exercisable, shares (in shares) | shares	64,588
Options exercisable, weighted-average exercise price (in dollars per share)	$ 56.72

STOCK-BASED COMPENSATION PLAN_4

STOCK-BASED COMPENSATION PLANS, Stock-Based Compensation Expense Recognized (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Options [Member]
Compensation Related Costs [Abstract]
Stock-based compensation expense related to incentive and non-qualified stock options recognized	$ 2.6	$ 2.2	$ 2.2
Income tax benefit recognized	0.6	0.8	0.8
Restricted Stock [Member]
Compensation Related Costs [Abstract]
Stock-based compensation expense related to incentive and non-qualified stock options recognized	$ 3.2	$ 2.7	$ 2.4

STOCK-BASED COMPENSATION PLAN_5

STOCK-BASED COMPENSATION PLANS, Assumptions Used to Estimate Value of Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
STOCK-BASED COMPENSATION PLANS [Abstract]
Fair value assumptions, method used	Black-Scholes model
Weighted-average Fair Value of Options Granted (in dollars per share)	$ 13.44	$ 12.78	$ 7.90
Assumptions [Abstract]
Weighted-average expected life	6 years 6 months	6 years 6 months	6 years 6 months
Future dividend yield	2.91%	3.19%	3.43%
Share price volatility	29.44%	29.71%	30.00%
Weighted-average risk-free interest rate	2.82%	2.31%	1.72%

STOCK-BASED COMPENSATION PLAN_6

STOCK-BASED COMPENSATION PLANS, Unrecognized Stock-Based Compensation Expense and Stock Option Exercises (Details) - Stock Options [Member] - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrecognized Stock-Based Compensation Expense and Stock Option Exercises [Abstract]
Unrecognized stock-based compensation expense related to non-vested stock options	$ 4.7
Weighted average period for recognition of unrecognized compensation cost	3 years 3 months 18 days
Total fair value of stock options vested	$ 2.3	$ 2.2	$ 2.1
Proceeds from stock option exercises	9.4	7.7
Related tax benefits from stock option exercises	$ 1.6	$ 2.3
Shares issued in connection with stock option exercise (in shares)	0.3	0.2
Total intrinsic value of options exercised	$ 8.4	$ 7.6	$ 10.3

STOCK-BASED COMPENSATION PLAN_7

STOCK-BASED COMPENSATION PLANS, Activity of Unvested Restricted Stock Awards (Details) - Restricted Stock [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Shares [Roll Forward]
Unvested, beginning of period (in shares)	230,873	253,830
Awards (in shares)	50,133	46,428
Forfeitures (in shares)	(3,429)	(4,863)
Vestings (in shares)	(56,514)	(64,522)
Unvested, end of period (in shares)	221,063	230,873	253,830
Weighted-average grant date fair value [Abstract]
Unvested, beginning of period (in dollars per share)	$ 34.06	$ 29.98
Awards (in dollars per share)	55.92	57.02
Forfeitures (in dollars per share)	34.95	24.78
Vestings (in dollars per share)	39.40	33.69
Unvested, end of period (in dollars per share)	$ 37.72	$ 34.06	$ 29.98
Unrecognized stock-based compensation expense	$ 4.6
Award vesting period	5 years
Weighted-average period for recognition of unrecognized compensation cost	3 years 2 months 12 days
Total fair value of restricted stock vested	$ 2.3	$ 2.2	$ 2.5

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
EARNINGS PER SHARE [Abstract]
Weighted-average anti-dilutive stock options outstanding (in shares)	400	200	300
Basic earnings per share [Abstract]
Net income	$ 168,641	$ 150,717	$ 103,812
Income attributable to unvested stock-based compensation awards	(744)	(597)	(550)
Income available to common shareholders	$ 167,897	$ 150,120	$ 103,262
Weighted-average common shares outstanding - basic (in shares)	51,165	48,843	44,091
Basic earnings per share (in dollars per share)	$ 3.28	$ 3.07	$ 2.34
Diluted earnings per share [Abstract]
Net income	$ 168,641	$ 150,717	$ 103,812
Income attributable to unvested stock-based compensation awards	(744)	(597)	(550)
Income available to common shareholders	$ 167,897	$ 150,120	$ 103,262
Weighted-average common shares outstanding (in shares)	51,165	48,843	44,091
Assumed exercise of stock options (in shares)	583	627	394
Weighted-average common shares outstanding - diluted (in shares)	51,748	49,470	44,485
Diluted earnings per share (in dollars per share)	$ 3.24	$ 3.03	$ 2.32
Cash dividends declared per share (in dollars per share)	$ 1.44	$ 1.32	$ 1.26
Stock Repurchase Program [Abstract]
Number of common shares authorized to be repurchased (in shares)	2,500	2,500
Number of common shares repurchased (in shares)	0	0

COMMITMENTS, CONTINGENT LIABI_3

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loss Contingency, Estimate [Abstract]
Contract amount of commitments and contingencies	$ 1,167,745	$ 1,103,786
Unused lines of credit	25,000
Federal Home Loan Bank unused borrowing capacity	1,620,000
Federal Reserve unused borrowing capacity	23,500
Federal Reserve required average total reserve	89,700
Federal Reserve requirement represented by cash on hand	76,600
Required deposit with Federal Reserve	13,100
Minimum [Member]
Loss Contingency, Estimate [Abstract]
Range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability	0
Maximum [Member]
Loss Contingency, Estimate [Abstract]
Range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability	1,000
Commitments to Extend Credit [Member]
Loss Contingency, Estimate [Abstract]
Contract amount of commitments and contingencies	1,134,576	1,080,004
Standby Letters of Credit [Member]
Loss Contingency, Estimate [Abstract]
Contract amount of commitments and contingencies	$ 33,169	$ 23,782

LEASES (Details)

LEASES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
LEASES [Abstract]
Rental expense	$ 9,000	$ 7,300	$ 5,800
Future minimum rental commitments [Abstract]
2,019	8,452
2,020	7,262
2,021	5,673
2,022	4,411
2,023	2,621
Thereafter	10,390
Total	$ 38,809

REGULATORY MATTERS (Details)

REGULATORY MATTERS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Tier 1 Leverage ratio [Abstract]
Tier 1 Leverage ratio, actual amount	$ 1,093,166	$ 995,860
Tier 1 Leverage ratio, actual ratio	11.08%	10.00%
Tier 1 leverage ratio for capital adequacy purposes, amount	$ 394,700	$ 398,183
Tier 1 leverage ratio for capital adequacy purposes, ratio	4.00%	4.00%
Tier 1 leverage capital to be well-capitalized under prompt corrective action, amount	$ 493,375	$ 497,729
Tier 1 leverage capital to be well-capitalized under prompt corrective action, ratio	5.00%	5.00%
Tier 1 risk-based capital [Abstract]
Tier 1 risk-based capital, actual amount	$ 1,093,166	$ 995,860
Tier 1 risk-based capital, actual ratio	18.23%	16.64%
Tier 1 risk-based capital for capital adequacy purposes, amount	$ 359,747	$ 358,988
Tier 1 risk-based capital for capital adequacy purposes, ratio	6.00%	6.00%
Tier 1 risk-based capital for capital adequacy purposes plus capital conservation buffer, amount	$ 472,168	$ 433,777
Tier 1 risk-based capital for capital adequacy purposes plus capital conservation buffer, ratio	7.875%	7.25%
Tier 1 risk based capital to be well-capitalized under prompt corrective action, amount	$ 479,662	$ 478,651
Tier 1 risk-based capital to be well-capitalized under prompt corrective action, ratio	8.00%	8.00%
Total risk-based capital [Abstract]
Total risk-based capital, actual amount	$ 1,142,927	$ 1,043,910
Total risk-based capital, actual ratio	19.06%	17.45%
Total risk-based capital for capital adequacy purposes, amount	$ 479,662	$ 478,651
Total risk-based capita for capital adequacy purposes, ratio	8.00%	8.00%
Total risk-based capital for capital adequacy purposes plus capital conservation buffer, amount	$ 592,083	$ 553,440
Total risk-based capita for capital adequacy purposes plus capital conservation buffer, ratio	9.875%	9.25%
Total risk based capital to be well-capitalized under prompt corrective action, amount	$ 599,578	$ 598,314
Total risk based capital to be well-capitalized under prompt corrective action, ratio	10.00%	10.00%
Common equity Tier 1 capital [Abstract]
Common equity Tier 1 capital, actual amount	$ 998,111	$ 876,685
Common equity Tier 1 capital, actual ratio	16.65%	14.65%
Common equity Tier 1 capital for capital adequacy purposes, amount	$ 269,810	$ 269,241
Common equity Tier 1 capital for capital adequacy purposes, ratio	4.50%	4.50%
Common equity Tier 1 capital for capital adequacy purposes plus capital conservation buffer, amount	$ 382,231	$ 344,030
Common equity Tier 1 capital for capital adequacy purposes plus capital conservation buffer, ratio	6.375%	5.75%
Common equity Tier 1 capital to be well-capitalized under prompt corrective action, amount	$ 389,726	$ 388,904
Common equity Tier 1 capital to be well-capitalized under prompt corrective action, ratio	6.50%	6.50%
Community Bank, N.A. [Member]
Tier 1 Leverage ratio [Abstract]
Tier 1 Leverage ratio, actual amount	$ 912,995	$ 859,538
Tier 1 Leverage ratio, actual ratio	9.32%	8.71%
Tier 1 leverage ratio for capital adequacy purposes, amount	$ 391,953	$ 394,981
Tier 1 leverage ratio for capital adequacy purposes, ratio	4.00%	4.00%
Tier 1 leverage capital to be well-capitalized under prompt corrective action, amount	$ 489,941	$ 493,726
Tier 1 leverage capital to be well-capitalized under prompt corrective action, ratio	5.00%	5.00%
Tier 1 risk-based capital [Abstract]
Tier 1 risk-based capital, actual amount	$ 912,995	$ 859,538
Tier 1 risk-based capital, actual ratio	15.35%	14.50%
Tier 1 risk-based capital for capital adequacy purposes, amount	$ 356,973	$ 355,641
Tier 1 risk-based capital for capital adequacy purposes, ratio	6.00%	6.00%
Tier 1 risk-based capital for capital adequacy purposes plus capital conservation buffer, amount	$ 468,527	$ 429,733
Tier 1 risk-based capital for capital adequacy purposes plus capital conservation buffer, ratio	7.875%	7.25%
Tier 1 risk based capital to be well-capitalized under prompt corrective action, amount	$ 475,964	$ 474,188
Tier 1 risk-based capital to be well-capitalized under prompt corrective action, ratio	8.00%	8.00%
Total risk-based capital [Abstract]
Total risk-based capital, actual amount	$ 962,756	$ 907,588
Total risk-based capital, actual ratio	16.18%	15.31%
Total risk-based capital for capital adequacy purposes, amount	$ 475,964	$ 474,188
Total risk-based capita for capital adequacy purposes, ratio	8.00%	8.00%
Total risk-based capital for capital adequacy purposes plus capital conservation buffer, amount	$ 587,518	$ 548,280
Total risk-based capita for capital adequacy purposes plus capital conservation buffer, ratio	9.875%	9.25%
Total risk based capital to be well-capitalized under prompt corrective action, amount	$ 594,955	$ 592,736
Total risk based capital to be well-capitalized under prompt corrective action, ratio	10.00%	10.00%
Common equity Tier 1 capital [Abstract]
Common equity Tier 1 capital, actual amount	$ 912,940	$ 859,483
Common equity Tier 1 capital, actual ratio	15.35%	14.50%
Common equity Tier 1 capital for capital adequacy purposes, amount	$ 267,730	$ 266,731
Common equity Tier 1 capital for capital adequacy purposes, ratio	4.50%	4.50%
Common equity Tier 1 capital for capital adequacy purposes plus capital conservation buffer, amount	$ 379,284	$ 340,823
Common equity Tier 1 capital for capital adequacy purposes plus capital conservation buffer, ratio	6.375%	5.75%
Common equity Tier 1 capital to be well-capitalized under prompt corrective action, amount	$ 386,721	$ 385,278
Common equity Tier 1 capital to be well-capitalized under prompt corrective action, ratio	6.50%	6.50%

PARENT COMPANY STATEMENTS, Cond

PARENT COMPANY STATEMENTS, Condensed Statements of Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets [Abstract]
Cash and cash equivalents	$ 211,834	$ 221,038	$ 173,857	$ 153,210
Investment in and advances to [Abstract]
Other assets	223,498	249,488
Total assets	10,607,295	10,746,198	8,666,437
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	157,459	180,567
Borrowings	97,939	122,814
Shareholders' equity	1,713,783	1,635,315	1,198,100	1,140,647
Total liabilities and shareholders' equity	10,607,295	10,746,198
Parent Company [Member]
Assets [Abstract]
Cash and cash equivalents	116,133	84,460	$ 151,127	$ 97,317
Investment securities	3,452	4,322
Investment in and advances to [Abstract]
Bank subsidiary	1,522,109	1,511,780
Non-bank subsidiaries	182,617	169,341
Other assets	8,957	9,150
Total assets	1,833,268	1,779,053
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	21,546	20,924
Borrowings	97,939	122,814
Shareholders' equity	1,713,783	1,635,315
Total liabilities and shareholders' equity	$ 1,833,268	$ 1,779,053

PARENT COMPANY STATEMENTS, Co_2

PARENT COMPANY STATEMENTS, Condensed Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Expenses [Abstract]
Interest on borrowings	$ 4,677	$ 3,904	$ 2,949
Acquisition expenses	(769)	25,986	1,706
Loss on debt prepayment	318	0	0
Other expenses	21,471	22,609	22,749
Income before tax benefit and equity in undistributed net income of subsidiaries	212,988	159,965	154,597
Income tax benefit	(44,347)	(9,248)	(50,785)
Net income	168,641	150,717	103,812
Other comprehensive (loss), net of tax [Abstract]
Changes in other comprehensive (loss)/income related to pension and other post retirement obligations	(11,204)	168	3,322
Changes in other comprehensive loss related to unrealized losses on available-for-sale securities	(30,402)	(11,065)	(14,714)
Other comprehensive (loss), net of tax	(41,398)	(10,897)	(11,392)
Comprehensive income	127,035	139,820	92,420
Parent Company [Member]
Dividends from subsidiaries [Abstract]
Bank subsidiary	98,000	91,000	89,000
Non-bank subsidiaries	9,250	35,500	1,750
Interest and dividends on investments	161	133	102
Total revenues	107,411	126,633	90,852
Expenses [Abstract]
Interest on borrowings	4,677	3,904	2,949
Acquisition expenses	0	91	429
Loss on debt prepayment	318	0	0
Other expenses	131	26	11
Total expenses	5,126	4,021	3,389
Income before tax benefit and equity in undistributed net income of subsidiaries	102,285	122,612	87,463
Income tax benefit	1,330	1,930	866
Income before equity in undistributed net income of subsidiaries	103,615	124,542	88,329
Equity in undistributed net income of subsidiaries	65,026	26,175	15,483
Net income	168,641	150,717	103,812
Other comprehensive (loss), net of tax [Abstract]
Changes in other comprehensive (loss)/income related to pension and other post retirement obligations	(11,204)	168	3,322
Changes in other comprehensive loss related to unrealized losses on available-for-sale securities	(30,402)	(11,065)	(14,714)
Other comprehensive (loss), net of tax	(41,606)	(10,897)	(11,392)
Comprehensive income	$ 127,035	$ 139,820	$ 92,420

PARENT COMPANY STATEMENTS, Co_3

PARENT COMPANY STATEMENTS, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities [Abstract]
Net income	$ 168,641	$ 150,717	$ 103,812
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Net change in other assets and other liabilities	10,252	26,090	(7,614)
Net cash provided by operating activities	221,408	189,674	135,771
Investing activities [Abstract]
Cash paid for acquisitions, net of cash acquired of $0, $150,534, and $0, respectively	(1,737)	(107,414)	(575)
Net cash provided by/(used in) investing activities	17,495	131,371	(121,998)
Financing activities [Abstract]
Repayment of borrowings	(25,207)	0	0
Issuance of common stock	6,443	4,563	10,543
Purchase of treasury stock	(298)	(3,306)	(3,470)
Sale of treasury stock	12,561	10,060	8,888
Increase in deferred compensation arrangements	298	3,306	0
Net cash (used in)/provided by financing activities	(248,107)	(273,864)	6,874
Change in cash and cash equivalents	(9,204)	47,181	20,647
Cash and cash equivalents at beginning of year	221,038	173,857	153,210
Cash and cash equivalents at end of year	211,834	221,038	173,857
Supplemental disclosures of cash flow information [Abstract]
Cash paid for interest	17,926	13,705	11,268
Supplemental disclosures of noncash financing activities [Abstract]
Dividends declared and unpaid	19,808	17,460	14,268
Common stock issued for acquisition	0	343,132	0
Cash acquired from acquisition	16	52,132	0
Parent Company [Member]
Operating activities [Abstract]
Net income	168,641	150,717	103,812
Adjustments to reconcile net income to net cash provided by operating activities [Abstract]
Equity in undistributed net income of subsidiaries	(65,026)	(26,175)	(15,483)
Net change in other assets and other liabilities	(1,084)	1,870	(215)
Net cash provided by operating activities	102,531	126,412	88,114
Investing activities [Abstract]
Proceeds from redemption of investment securities	776	0	0
Cash paid for acquisitions, net of cash acquired of $0, $150,534, and $0, respectively	0	(139,471)	0
Capital contributions to subsidiaries	0	(11,063)	0
Net cash provided by/(used in) investing activities	776	(150,534)	0
Financing activities [Abstract]
Repayment of borrowings	(25,207)	0	0
Issuance of common stock	12,507	9,700	15,326
Purchase of treasury stock	(298)	(3,306)	(3,470)
Sale of treasury stock	12,561	10,060	8,888
Increase in deferred compensation arrangements	298	3,306	0
Cash dividends paid	(71,495)	(62,305)	(55,048)
Net cash (used in)/provided by financing activities	(71,634)	(42,545)	(34,304)
Change in cash and cash equivalents	31,673	(66,667)	53,810
Cash and cash equivalents at beginning of year	84,460	151,127	97,317
Cash and cash equivalents at end of year	116,133	84,460	151,127
Supplemental disclosures of cash flow information [Abstract]
Cash paid for interest	4,857	3,826	2,909
Supplemental disclosures of noncash financing activities [Abstract]
Dividends declared and unpaid	19,808	17,460	14,268
Capital contributions to subsidiaries	0	513,769	0
Common stock issued for acquisition	0	343,132	0
Cash acquired from acquisition	$ 0	$ 150,534	$ 0

FAIR VALUE, Financial Assets an

FAIR VALUE, Financial Assets and Liabilities Accounted for at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	$ 2,936,049
Equity securities	432	$ 0
Available-for-sale investment securities	2,936,049	3,031,088
Derivative asset		89
U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,023,753	2,054,071
Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	459,154	528,956
Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	382,477	357,538
Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,546	2,623
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	68,119	87,374
Recurring [Member]
Available-for-sale investment securities [Abstract]
Equity securities	432
Marketable equity securities		526
Available-for-sale investment securities	2,936,049	3,031,088
Mortgage loans held for sale	83	461
Total	2,936,615	3,031,802
Recurring [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		89
Recurring [Member] | Forward Sales Commitments [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		4
Recurring [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	793	1,064
Derivative liability	(742)	(904)
Recurring [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,023,753	2,054,071
Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	459,154	528,956
Recurring [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	382,477	357,538
Recurring [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,546	2,623
Recurring [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	68,119	87,374
Recurring [Member] | Level 1 [Member]
Available-for-sale investment securities [Abstract]
Equity securities	432
Marketable equity securities		526
Available-for-sale investment securities	1,896,931	1,909,816
Mortgage loans held for sale	0	0
Total	1,897,363	1,909,816
Recurring [Member] | Level 1 [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		0
Recurring [Member] | Level 1 [Member] | Forward Sales Commitments [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		0
Recurring [Member] | Level 1 [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	0	0
Derivative liability	0	0
Recurring [Member] | Level 1 [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	1,896,931	1,909,290
Recurring [Member] | Level 1 [Member] | Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 1 [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 1 [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 1 [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 2 [Member]
Available-for-sale investment securities [Abstract]
Equity securities	0
Marketable equity securities		0
Available-for-sale investment securities	1,039,118	1,121,272
Mortgage loans held for sale	83	461
Total	1,039,252	1,121,897
Mortgage loans held for sale, at principal value	100
Recurring [Member] | Level 2 [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		0
Recurring [Member] | Level 2 [Member] | Forward Sales Commitments [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		4
Recurring [Member] | Level 2 [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	793	1,064
Derivative liability	(742)	(904)
Recurring [Member] | Level 2 [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	126,822	144,781
Recurring [Member] | Level 2 [Member] | Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	459,154	528,956
Recurring [Member] | Level 2 [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	382,477	357,538
Recurring [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,546	2,623
Recurring [Member] | Level 2 [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	68,119	87,374
Recurring [Member] | Level 3 [Member]
Available-for-sale investment securities [Abstract]
Equity securities	0
Marketable equity securities		0
Available-for-sale investment securities	0	0
Mortgage loans held for sale	0	0
Total	0	89
Recurring [Member] | Level 3 [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		89
Recurring [Member] | Level 3 [Member] | Forward Sales Commitments [Member]
Available-for-sale investment securities [Abstract]
Derivative asset		0
Recurring [Member] | Level 3 [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	0	0
Derivative liability	0	0
Recurring [Member] | Level 3 [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 3 [Member] | Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 3 [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 3 [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Recurring [Member] | Level 3 [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	$ 0	$ 0

FAIR VALUE, Assets and Liabilit

FAIR VALUE, Assets and Liabilities Measured on Nonrecurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	$ 1,102
Other real estate owned	1,320	$ 1,915
Valuation allowance	956	804
Fair value of MSRs at end of period	2,397	2,473
Carrying value before valuation allowance at end of period	1,137	1,358	$ 1,435
Mortgage Servicing Rights [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Valuation allowance	0
Fair value of MSRs at end of period	2,400
Carrying value before valuation allowance at end of period	$ 1,100
Level 3 [Member] | Other Real Estate Owned [Member] | us-gaap_MarketApproachValuationTechniqueMember | Minimum [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Discount rate	9.00%
Level 3 [Member] | Other Real Estate Owned [Member] | us-gaap_MarketApproachValuationTechniqueMember | Maximum [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Discount rate	69.00%
Non-recurring [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	$ 1,102	0
Other real estate owned	1,320	1,915
Total	2,422	1,915
Non-recurring [Member] | Level 1 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	0	0
Other real estate owned	0	0
Total	0	0
Non-recurring [Member] | Level 2 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	0	0
Other real estate owned	0	0
Total	0	0
Non-recurring [Member] | Level 3 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	1,102	0
Other real estate owned	1,320	1,915
Total	$ 2,422	$ 1,915

FAIR VALUE, Significant Unobser

FAIR VALUE, Significant Unobservable Inputs (Details) $ in Thousands	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans	$ 1,102
Other real estate owned	$ 1,320	$ 1,915
Other real estate owned, Valuation Technique [Extensible List]	us-gaap:MarketApproachValuationTechniqueMember	us-gaap:MarketApproachValuationTechniqueMember
Other real estate owned, Measurement Input [Extensible List]	us-gaap:MeasurementInputCostToSellMember	us-gaap:MeasurementInputCostToSellMember
Commitments to originate real estate loans for sale		$ 89
Commitments to originate real estate loans for sale, Valuation Technique [Extensible List]		us-gaap:ValuationTechniqueDiscountedCashFlowMember
Commitments to originate real estate loans for sale, measurement input		0.01
Minimum [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Other real estate owned, measurement input	0.090	0.090
Minimum [Member] | Fair Value of Collateral [Member] | Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans measurement input	0.090
Maximum [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Other real estate owned, measurement input	0.693	0.990
Maximum [Member] | Fair Value of Collateral [Member] | Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans measurement input	0.354
Weighted Average [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Other real estate owned, measurement input	0.238	0.385
Weighted Average [Member] | Fair Value of Collateral [Member] | Estimated Cost of Disposal/Market Adjustment [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans measurement input	0.288

FAIR VALUE, Carrying Amounts an

FAIR VALUE, Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Carrying Value [Member]
Financial assets [Abstract]
Net loans	$ 6,231,837	$ 6,209,174
Financial liabilities [Abstract]
Deposits	8,322,371	8,444,420
Short-term borrowings	54,400	24,000
Securities sold under agreement to repurchase, short-term	259,367	337,011
Other long-term debt	1,976	2,071
Subordinated debt held by unconsolidated subsidiary trusts	97,939	122,814
Fair Value [Member]
Financial assets [Abstract]
Net loans	6,247,939	6,244,941
Financial liabilities [Abstract]
Deposits	8,308,765	8,431,481
Short-term borrowings	54,400	24,000
Securities sold under agreement to repurchase, short-term	259,367	337,011
Other long-term debt	1,921	2,021
Subordinated debt held by unconsolidated subsidiary trusts	$ 97,939	$ 122,814

DERIVATIVE INSTRUMENTS (Details

DERIVATIVE INSTRUMENTS (Details) - Interest Rate Swap [Member] $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Derivative Instruments [Abstract]
Derivative, notional amount	$ 37
Derivative weighted average receive rate	4.34%
Derivative weighted average pay rate	3.84%
Weighted average maturity period	5 years 6 months
Other Assets [Member]
Derivative Instruments [Abstract]
Fair value of derivate assets	$ 0.7
Other Liabilities [Member]
Derivative Instruments [Abstract]
Fair value of derivate liability	0.7
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative Instruments [Abstract]
Derivative, notional amount	$ 6.6
Derivative weighted average receive rate	2.92%
Derivative weighted average pay rate	3.11%
Weighted average maturity period	14 years 6 months
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member] | Other Assets [Member]
Derivative Instruments [Abstract]
Fair value of derivate assets	$ 0.1

VARIABLE INTEREST ENTITIES (Det

VARIABLE INTEREST ENTITIES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and cash equivalents	$ 211,834	$ 221,038	$ 173,857	$ 153,210
Premises and equipment, net	119,988	123,393
Other assets	223,498	249,488
Variable Interest Entity, Primary Beneficiary [Member] | 706 North Clinton [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and cash equivalents	104	74
Premises and equipment, net	6,109	6,266
Other assets	33	5
Total assets	6,246	6,345
Total liabilities	0	$ 0
Minority interest	3,100
Loss of minority interest	4,800
Minority interest loss exposure related to financing agreement	$ 1,700
Variable Interest Entity, Primary Beneficiary [Member] | 706 North Clinton [Member] | Oneida Preferred Funding II LLC [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Percentage of membership interest	50.00%

SEGMENT INFORMATION (Details)

SEGMENT INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Information about reportable segments [Abstract]
Net interest income	$ 345,055	$ 315,675	$ 273,896
Provision for loan losses	10,837	10,984	8,076
Noninterest revenue	224,059	202,423	155,625
Amortization of intangible assets	18,155	16,941	5,479
Acquisition expenses	(769)	25,986	1,706
Other operating expenses	327,903	304,222	259,663
Income before income taxes	212,988	159,965	154,597
Assets	10,607,295	10,746,198	8,666,437
Goodwill	733,503	734,430	465,142
Core deposit intangibles & Other intangibles	73,846	90,658	15,702
Eliminations [Member]
Information about reportable segments [Abstract]
Net interest income	0	0	0
Provision for loan losses	0	0	0
Noninterest revenue	(2,993)	(2,858)	(2,442)
Amortization of intangible assets	0	0	0
Acquisition expenses	0	0	0
Other operating expenses	(2,993)	(2,858)	(2,442)
Income before income taxes	0	0	0
Assets	(66,076)	(29,638)	(41,790)
Goodwill	0	0	0
Core deposit intangibles & Other intangibles	0	0	0
Banking [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	344,551	315,025	273,542
Provision for loan losses	10,837	10,984	8,076
Noninterest revenue	75,399	73,337	66,059
Amortization of intangible assets	6,429	5,296	2,682
Acquisition expenses	(782)	24,549	1,005
Other operating expenses	231,362	218,608	190,263
Income before income taxes	172,104	128,925	137,575
Assets	10,397,623	10,505,919	8,598,057
Goodwill	629,916	629,916	440,870
Core deposit intangibles & Other intangibles	18,596	25,025	7,107
Employee Benefit Services [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	376	396	162
Provision for loan losses	0	0	0
Noninterest revenue	94,449	82,743	48,261
Amortization of intangible assets	8,015	8,578	420
Acquisition expenses	7	1,194	445
Other operating expenses	56,275	51,138	36,892
Income before income taxes	30,528	22,229	10,666
Assets	207,460	203,369	38,742
Goodwill	83,275	84,449	8,019
Core deposit intangibles & Other intangibles	44,545	52,288	666
All Other [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	128	254	192
Provision for loan losses	0	0	0
Noninterest revenue	57,204	49,201	43,747
Amortization of intangible assets	3,711	3,067	2,377
Acquisition expenses	6	243	256
Other operating expenses	43,259	37,334	34,950
Income before income taxes	10,356	8,811	6,356
Assets	68,288	66,548	71,428
Goodwill	20,312	20,065	16,253
Core deposit intangibles & Other intangibles	$ 10,705	$ 13,345	$ 7,929

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) $ in Thousands	Jan. 22, 2019USD ($)Branch	Jan. 02, 2019USD ($)	Dec. 31, 2018USD ($)County	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Acquisitions [Abstract]
Cash			$ 1,737	$ 107,414	$ 575
Upstate New York [Member]
Acquisitions [Abstract]
Number of counties where the bank has facilities | County			35
Subsequent Event [Member] | Kinderhook Bank Corp [Member]
Acquisitions [Abstract]
Cash	$ 93,400
Number of branch locations added upon merger | Branch	11
Subsequent Event [Member] | Kinderhook Bank Corp [Member] | Upstate New York [Member]
Acquisitions [Abstract]
Number of counties where the bank has facilities | Branch	5
Subsequent Event [Member] | Wealth Resources Network, Inc [Member]
Acquisitions [Abstract]
Cash		$ 1,200
Subsequent Event [Member] | Wealth Resources Network, Inc [Member] | Customer Lists [Member]
Acquisitions [Abstract]
Intangibles		$ 1,200