Community Bank System (CBU) 10-Q 11 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Cover [Abstract]
Entity Registrant Name	COMMUNITY BANK SYSTEM, INC.
Entity Central Index Key	0000723188
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		52,094,944
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-13695
Entity Tax Identification Number	16-1213679
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	5790 Widewaters Parkway
Entity Address, City or Town	DeWitt
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	13214
City Area Code	315
Local Phone Number	445-2282
Title of 12(b) Security	Common Stock, $1.00 par value per share
Trading Symbol	CBU
Security Exchange Name	NYSE

CONSOLIDATED STATEMENTS OF COND

CONSOLIDATED STATEMENTS OF CONDITION (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Cash and cash equivalents	$ 529,336	$ 205,030
Available-for-sale investment securities (cost of $2,986,577 and $3,011,551, respectively)	3,141,882	3,044,428
Equity and other securities (cost of $42,579 and $42,965, respectively)	43,499	43,915
Loans held for sale, at fair value	3,272	0
Loans	6,866,092	6,890,543
Allowance for credit losses	(55,652)	(49,911)
Net loans	6,810,440	6,840,632
Goodwill, net	773,473	773,810
Core deposit intangibles, net	15,001	16,418
Other intangibles, net	44,445	46,695
Intangible assets, net	832,919	836,923
Premises and equipment, net	162,602	164,638
Accrued interest and fees receivable	36,724	31,647
Other assets	248,309	243,082
Total assets	11,808,983	11,410,295
Liabilities:
Noninterest-bearing deposits	2,491,720	2,465,902
Interest-bearing deposits	6,812,262	6,529,065
Total deposits	9,303,982	8,994,967
Overnight Federal Home Loan Bank borrowings	0	8,300
Securities sold under agreement to repurchase, short-term	204,991	241,708
Other Federal Home Loan Bank borrowings	3,727	3,750
Subordinated notes payable	13,775	13,795
Subordinated debt held by unconsolidated subsidiary trusts	77,320	77,320
Accrued interest and other liabilities	228,557	215,221
Total liabilities	9,832,352	9,555,061
Commitments and contingencies (See Note J)
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; 52,189,314 and 51,974,726 shares issued, respectively	52,190	51,975
Additional paid-in capital	935,924	927,337
Retained earnings	902,148	882,851
Accumulated other comprehensive income (loss)	83,444	(10,226)
Treasury stock, at cost (158,222 shares, including 158,092 shares held by deferred compensation arrangements at March 31, 2020 and 180,803 shares including 179,548 shares held by deferred compensation arrangements at December 31, 2019, respectively)	(6,005)	(6,823)
Deferred compensation arrangements (158,092 and 179,548 shares, respectively)	8,930	10,120
Total shareholders' equity	1,976,631	1,855,234
Total liabilities and shareholders' equity	$ 11,808,983	$ 11,410,295

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF CONDITION (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Available-for-sale investment securities, cost	$ 2,986,577	$ 3,011,551
Equity and other securities, cost	$ 42,579	$ 42,965
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)	52,189,314	51,974,726
Treasury stock, shares at cost (in shares)	158,222	180,803
Shares held by deferred compensation arrangements (in shares)	158,092	179,548

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest income:
Interest and fees on loans	$ 78,565	$ 73,703
Interest and dividends on taxable investments	15,329	16,087
Interest and dividends on nontaxable investments	3,101	2,891
Total interest income	96,995	92,681
Interest expense:
Interest on deposits	5,545	4,107
Interest on borrowings	558	621
Interest on subordinated notes payable	185	0
Interest on subordinated debt held by unconsolidated subsidiary trusts	653	1,094
Total interest expense	6,941	5,822
Net interest income	90,054	86,859
Provision for credit losses	5,594	2,422
Net interest income after provision for credit losses	84,460	84,437
Noninterest revenues:
Deposit service fees	16,283	15,864
Mortgage banking	916	201
Other banking services	895	1,335
Employee benefit services	25,366	24,054
Insurance services	8,058	7,862
Wealth management services	7,134	6,349
Unrealized (loss) gain on equity securities	(30)	31
Total noninterest revenues	58,622	55,696
Noninterest expenses:
Salaries and employee benefits	58,251	53,379
Occupancy and equipment	10,739	10,288
Data processing and communications	10,413	9,399
Amortization of intangible assets	3,667	4,130
Legal and professional fees	3,151	2,720
Business development and marketing	2,513	2,788
Acquisition expenses	369	534
Other expenses	4,560	5,414
Total noninterest expenses	93,663	88,652
Income before income taxes	49,419	51,481
Income taxes	9,285	9,535
Net income	$ 40,134	$ 41,946
Basic earnings per share (in dollars per share)	$ 0.77	$ 0.81
Diluted earnings per share (in dollars per share)	$ 0.76	$ 0.80

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Pension and other post retirement obligations:
Amortization of actuarial losses included in net periodic pension cost, gross	$ 820	$ 651
Tax effect	(197)	(159)
Amortization of actuarial losses included in net periodic pension cost, net	623	492
Amortization of prior service cost included in net periodic pension cost, gross	15	(29)
Tax effect	(3)	7
Amortization of prior service cost included in net periodic pension cost, net	12	(22)
Other comprehensive income related to pension and other post retirement obligations, net of taxes	635	470
Unrealized gains on available-for-sale securities:
Net unrealized holding gains arising during period, gross	122,428	23,905
Tax effect	(29,393)	(5,832)
Net unrealized holding gains arising during period, net	93,035	18,073
Other comprehensive income related to unrealized gains on available-for-sale securities, net of taxes	93,035	18,073
Other comprehensive income, net of tax	93,670	18,543
Net income	40,134	41,946
Comprehensive income	133,804	$ 60,489
Accumulated Other Comprehensive Income (Loss) By Component:
Unrealized (loss) for pension and other post-retirement obligations	(45,340)		$ (46,175)
Tax effect	11,093		11,293
Net unrealized (loss) for pension and other post-retirement obligations	(34,247)		(34,882)
Unrealized gain on available-for-sale securities	155,305		32,877
Tax effect	(37,614)		(8,221)
Net unrealized gain on available-for-sale securities	117,691		24,656
Accumulated other comprehensive income (loss)	$ 83,444		$ (10,226)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Common Stock Shares Outstanding [Member]	Common Stock Amount Issued [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Cumulative Effect of Change in Accounting Principle - Current Expected Credit Losses [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock [Member]	Deferred Compensation Arrangements [Member]	Total	Cumulative Effect of Change in Accounting Principle - Current Expected Credit Losses [Member]
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				41,946					41,946
Other comprehensive income, net of tax						18,543			18,543
Dividends declared:
Common				(19,576)					(19,576)
Common stock activity under employee stock plans		151	(995)						(844)
Common stock activity under employee stock plans (in shares)	150,919
Stock-based compensation			1,391						1,391
Distribution of stock under deferred compensation arrangements			1,064				830	(1,894)	0
Distribution of stock under deferred compensation arrangements (in shares)	32,431
Treasury stock issued to benefit plans, net			709				1,097	79	1,885
Treasury stock issued to benefit plans, net (in shares)	30,197
Balance at Mar. 31, 2019		51,728	913,917	817,933		(26,762)	(9,601)	9,913	1,757,128
Balance (in shares) at Mar. 31, 2019	51,471,371
Balance at Dec. 31, 2019		51,975	927,337	882,851	$ 530	(10,226)	(6,823)	10,120	1,855,234	$ 530
Balance (in shares) at Dec. 31, 2019	51,793,923
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				40,134					40,134
Other comprehensive income, net of tax						93,670			93,670
Dividends declared:
Common				(21,367)					(21,367)
Common stock activity under employee stock plans		215	6,184						6,399
Common stock activity under employee stock plans (in shares)	214,588
Stock-based compensation			1,952						1,952
Distribution of stock under deferred compensation arrangements			415				849	(1,264)	0
Distribution of stock under deferred compensation arrangements (in shares)	22,497
Treasury stock issued to benefit plans, net			36				(31)	74	79
Treasury stock issued to benefit plans, net (in shares)	84
Balance at Mar. 31, 2020		$ 52,190	$ 935,924	$ 902,148		$ 83,444	$ (6,005)	$ 8,930	$ 1,976,631
Balance (in shares) at Mar. 31, 2020	52,031,092

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Dividends declared:
Dividends declared per common share (in dollars per share)	$ 0.41	$ 0.38

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net income	$ 40,134	$ 41,946
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	4,079	3,830
Amortization of intangible assets	3,667	4,130
Net accretion on securities, loans and borrowings	(2,113)	(1,944)
Stock-based compensation	1,952	1,391
Provision for credit losses	5,594	2,422
Amortization of mortgage servicing rights	82	98
Unrealized loss (gain) on equity securities	30	(31)
Income from bank-owned life insurance policies	(408)	(391)
Net loss on sale of loans and other assets	9	22
Change in other assets and other liabilities	(26,332)	(16,864)
Net cash provided by operating activities	26,694	34,609
Investing activities:
Proceeds from maturities, calls, and paydowns of available-for-sale investment securities	61,753	52,520
Proceeds from maturities and redemptions of equity and other investment securities	404	2,460
Purchases of available-for-sale investment securities	(34,597)	(13,388)
Purchases of equity and other securities	(18)	(24)
Net decrease in loans	25,446	11,847
Cash paid for acquisitions, net of cash acquired of $0 and $0, respectively	0	(1,200)
Purchases of premises and equipment, net	(3,020)	(1,227)
Real estate tax credit investments	(550)	(564)
Net cash provided by investing activities	49,418	50,424
Financing activities:
Net increase in deposits	309,015	297,291
Net decrease in borrowings	(45,040)	(63,910)
Issuance of common stock	6,399	(844)
Purchases of treasury stock	(74)	(79)
Sales of treasury stock	79	1,885
Increase in deferred compensation arrangements	74	79
Cash dividends paid	(21,268)	(19,806)
Withholding taxes paid on share-based compensation	(991)	(3,119)
Net cash provided by financing activities	248,194	211,497
Change in cash and cash equivalents	324,306	296,530
Cash and cash equivalents at beginning of period	205,030	211,834
Cash and cash equivalents at end of period	529,336	508,364
Supplemental disclosures of cash flow information:
Cash paid for interest	6,888	5,684
Cash paid for income taxes	9,642	4,486
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	21,441	19,578
Transfers from loans to other real estate	$ 779	$ 412

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Investing activities:
Cash acquired from acquisition	$ 0	$ 0

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2020
BASIS OF PRESENTATION [Abstract]
BASIS OF PRESENTATION	NOTE A: BASIS OF PRESENTATION The interim financial data as of and for the three months ended March 31, 2020 is unaudited; however, in the opinion of Community Bank System, Inc. (the “Company”), the interim data includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the results for the interim periods in conformity with generally accepted accounting principles in the United States of America (“GAAP”). The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period.

ACQUISITIONS

ACQUISITIONS	3 Months Ended
	Mar. 31, 2020
ACQUISITIONS [Abstract]
ACQUISITIONS	NOTE B: ACQUISITIONS Pending Acquisition – Steuben Trust Corporation On October 21, 2019, the Company announced that it had entered into a definitive agreement to acquire Steuben Trust Corporation (“Steuben”), parent company of Steuben Trust Company, a New York State chartered bank headquartered in Hornell, New York. Based on the Company’s closing stock price on April 30, 2020 of $62.49, the transaction was valued at approximately $106.7 million in Company stock and cash. Steuben currently operates 14 branch locations in Western New York. The acquisition will extend the Company’s footprint into two new counties in Western New York State and enhance the Company’s presence in four Western New York State counties in which it currently operates. The Steuben shareholders approved the merger with the Company at its Special Meeting held on March 3, 2020. The acquisition is scheduled to close during the second quarter of 2020. However, due to the novel Coronavirus (“COVID-19”) On September 18, 2019, the Company, through its subsidiary, Community Investment Services, Inc. (“CISI”), completed its acquisition of certain assets of a practice engaged in the financial services business headquartered in Syracuse, New York. The Company paid $0.5 million in cash to acquire a customer list, and recorded a $0.5 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 July 12, 2019, the Company completed its merger with Kinderhook Bank Corp. (“Kinderhook”), parent company of The National Union Bank of Kinderhook, headquartered in Kinderhook, New York, for $93.4 million in cash. The merger added 11 branch locations across a five county area in the Capital District of Upstate New York. The merger resulted in the acquisition of $642.8 million of assets, including $479.9 million of loans and $39.8 million of investment securities, as well as $568.2 million of deposits and $40.0 million in goodwill. The effects of the acquired assets and liabilities have been included in the consolidated financial statements since that date. Revenues, excluding interest income on acquired investments, 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. The Company paid $1.2 million in cash to acquire a customer list from Wealth Resources, 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. 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 acquisitions, and were subject to adjustment based on updated information not available at the time of the acquisitions. During the fourth quarter of 2019, associated with the Kinderhook acquisition, the carrying amount of deposits increased by $0.08 million, loans decreased by $0.05 million, other liabilities increased by $0.04 million, other assets decreased by $0.04 million, and accrued interest and fees receivable increased by $0.01 million as a result of updated information not available at the time of acquisition. Goodwill associated with the Kinderhook acquisition increased by $0.2 million as a result of these adjustments. During the first quarter of 2020, the carrying amount of other liabilities associated with the Kinderhook acquisition decreased by $0.3 million as a result of an adjustment to accrued income taxes and deferred income taxes. Goodwill associated with the Kinderhook acquisition decreased $0.3 million as a result of this adjustment. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed after considering the measurement period adjustments described above: 2019 (000s omitted) Kinderhook Other (1) Total Consideration paid : Cash $ 93,384 $ 1,650 $ 95,034 Total net consideration paid 93,384 1,650 95,034 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 90,381 0 90,381 Investment securities 39,770 0 39,770 Loans 479,877 0 479,877 Premises and equipment 13,970 0 13,970 Accrued interest and fees receivable 1,130 0 1,130 Other assets 14,109 0 14,109 Core deposit intangibles 3,573 0 3,573 Other intangibles 0 1,650 1,650 Deposits (568,161 ) 0 (568,161 ) Other liabilities (2,922 ) 0 (2,922 ) Other Federal Home Loan Bank borrowings (2,420 ) 0 (2,420 ) Subordinated notes payable (13,831 ) 0 (13,831 ) Subordinated debt held by unconsolidated subsidiary trusts (2,062 ) 0 (2,062 ) Total identifiable assets, net 53,414 1,650 55,064 Goodwill $ 39,970 $ 0 $ 39,970 (1) completed by CISI in 2019. Under ASC 310-30, acquired On January 1, 2020, the Company adopted ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326) which replaces the ASC 310-30 acquired impaired loans methodology described above with the purchased credit deteriorated (“PCD”) methodology discussed in Note C: Accounting Policies. The following is a summary of the loans acquired from Kinderhook at the date of acquisition: (000s omitted) Acquired Impaired Loans Acquired Non-impaired Loans Total Acquired Loans Contractually required principal and interest at acquisition $ 13,350 $ 636,384 $ 649,734 Contractual cash flows not expected to be collected (4,176 ) (5,472 ) (9,648 ) Expected cash flows at acquisition 9,174 630,912 640,086 Interest component of expected cash flows (551 ) (159,658 ) (160,209 ) Fair value of acquired loans $ 8,623 $ 471,254 $ 479,877 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 fair value of subordinated notes payable was estimated using discounted cash flows and interest rates being offered on similar securities. Subordinated notes payable assumed with the Kinderhook acquisition included $3.0 million of subordinated notes with a fixed interest rate of 6.0% maturing in February 2028 November 2025 The core deposit intangibles and other intangibles related to both acquisitions completed by CISI in 2019 and the Direct costs related to the acquisitions were expensed as incurred. Merger and acquisition integration-related expenses amount to $0.4 million and $0.5 million during the three months ended March 31, 2020 and the three months ended March 31, 2019, respectively, and have been separately stated in the consolidated statements of income.

ACCOUNTING POLICIES

ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2020
ACCOUNTING POLICIES [Abstract]
ACCOUNTING POLICIES	NOTE C: ACCOUNTING POLICIES The accounting policies of the Company, as applied in the consolidated interim financial statements presented herein, are substantially the same as those followed on an annual basis as presented on pages through of the Annual Report on Form -K for the year ended December filed with the Securities and Exchange Commission (“SEC”) on March except as noted below. The accounting policies of the Company effective for the comparative periods presented prior to the adoption of ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326) are presented on the Form 10-K referenced above. The extent to which COVID-19 impacts the Company’s business and financial results will depend on numerous evolving factors including, but not limited to: the magnitude and duration of COVID-19, the extent to which it will impact national and international macroeconomic conditions including interest rates, unemployment rates, the speed of the anticipated recovery, and governmental and business reactions to the pandemic. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts COVID-19 as of March 31, 2020 and through the date of this Quarterly Report on Form 10-Q. The accounting matters assessed included, but were not limited to, the Company’s allowance for credit losses, decrease in fee and interest income, and the carrying value of the goodwill and other long-lived assets. While there was not a material impact to the Company’s consolidated financial statements as of and for the quarter ended March 31, 2020, the Company’s future assessment of the magnitude and duration of COVID-19, as well as other factors, could result in material impacts to the Company’s consolidated financial statements in future reporting periods. 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 or through March 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 March or December Equity securities with a readily determinable fair value are reported at fair value with net unrealized gains and losses recognized in the consolidated statements of income. Certain equity securities that do not have a readily determinable fair value are stated at cost, 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. Allowance for Credit Losses – Debt Securities For held-to-maturity debt securities, the Company measures expected credit losses on a collective basis by major security type. The estimates of expected credit losses considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. Accrued interest receivable on held-to-maturity securities is excluded from the estimates of credit losses. For available-for-sale debt securities in an unrealized loss position, the Company assesses whether it intends to sell, or it more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through income. For available-for-sale debt securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the security structure, recent security collateral performance metrics, if applicable, external credit ratings, failure of the issuer to make scheduled interest or principal payments, judgment about and expectations of future performance, and relevant independent industry research, analysis, and forecasts. The severity of the impairment and the length of time the security has been impaired is also considered in the assessment. This assessment involves a high degree of subjectivity and judgment that is based on the information available to management at a point in time. If this assessment indicates that a credit loss exists, the present value of the cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected from the security is less than the amortized cost basis of the security, a credit loss exists and an allowance for credit losses is recorded, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. Changes in the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. Losses are charged against the allowance when management believes the uncollectibility of an available-for-sale security is confirmed or when either of the criteria regarding intent or requirement to sell is met. Accrued interest receivable on available-for-sale debt securities, included in accrued interest and fees receivable on the consolidated statements of condition, totaled at March and is excluded from the estimate of credit losses. Loans Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at amortized cost, net of allowance for credit losses. Amortized cost is the principal balance outstanding, net of purchase premiums and discounts, and deferred loan fees and costs. 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. Accrued interest receivable on loans, included in accrued interest and fees receivable on the consolidated statements of condition, totaled at March and is excluded from the estimate of credit losses and amortized cost basis of loans. An allowance for credit losses is not measured for accrued interest receivable on loans as the Company writes off the uncollectible accrued interest balance in a timely manner. 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 90 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. 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 Credit Losses – Loans The allowance for credit losses is a valuation account that is netted against the loans’ amortized cost basis to present the net amount expected to be collected on the loans. Loans are charged off against the allowance when management believes the uncollectibility of a loan balance is confirmed. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off. Management estimates the allowance balance using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. Historical credit loss experience provides the basis for the estimation of expected credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics such as differences in underwriting standards, portfolio mix, acquired loans, delinquency level, risk ratings or term of loans as well as changes in macroeconomic conditions, such as changes in unemployment rates, property values such as home prices, commercial real estate prices and automobile prices, gross domestic product, recession probability, and other relevant factors. The segments of the Company’s loan portfolio are disaggregated into the following classes that allow management to monitor risk and performance: • Business lending is comprised of general purpose commercial and industrial loans including, but not limited to agricultural-related and dealer floor plans, loans to not-for-profit enterprises, as well as mortgages on commercial property. The portfolio segment is further broken into portfolio classes based on risks associated with the collateral supporting the loans. Each class of business lending can also have different payment structures. Business lending loans are generally higher dollar loans and a large portion are risk rated at least annually. • Consumer mortgages consist primarily of fixed rate residential instruments, typically – years in contractual term, secured by liens on real property. FICO scores are used to monitor higher risks related to this type of lending with FICO AB referring to higher tiered loans with FICO scores greater than or equal to 720 as compared to FICO CDE with lower FICO scores less than 720 and potentially higher risk. • Consumer indirect consists primarily of installment loans originated through selected dealerships and are generally secured by automobiles, marine and other recreational vehicles. Collateral securing the loans was used to further disaggregate this portfolio as charge-offs can vary depending on the purpose of the loan. Non-auto loans often have longer terms, and generally have higher risk due to declines in collateral value given the nature of the property. • Consumer direct consists of all other loans to consumers such as personal installment loans and check credit lines of credit. • Home equity products are installment loans or lines of credit most often secured by a or lien position on residential real estate with terms up to years. The allowance for credit losses is measured on a collective (pool) basis when similar risk characteristics exist, including collateral type, credit ratings/scores, size, duration, interest rate structure, industry, geography, origination vintage, and payment structure. The Company has identified the following portfolio segments and classes and measures the allowance for credit losses using the following methods: Loan Portfolio Segment Loan Portfolio Class Allowance for Credit Losses Methodology Business lending Commercial real estate multi family Cumulative loss rate Business lending Commercial real estate non-owner occupied Cumulative loss rate Business lending Commercial real estate owner occupied Cumulative loss rate Business lending Commercial and industrial loans Vintage loss rate Business lending Commercial and industrial lines of credit Line loss Business lending Municipal Cumulative loss rate Business lending Other business Cumulative loss rate Consumer mortgage Consumer mortgage FICO AB Cumulative loss rate Consumer mortgage Consumer mortgage FICO CDE Cumulative loss rate Consumer indirect Indirect new auto Vintage loss rate Consumer indirect Indirect used auto Vintage loss rate Consumer indirect Indirect non-auto Vintage loss rate Consumer direct Consumer check credit Line loss Consumer direct Consumer direct Vintage loss rate Home equity Home equity fixed rate Vintage loss rate Home equity Home equity lines of credit Line loss The cumulative loss rate method uses historical loss data applied against multiple pools of loans and uses a quantitatively based management overlay in order to capture the risk for a loan’s entire expected life. These loss rates are then applied to current balances to achieve a required reserve before qualitative adjustments. The line loss method calculates the quantitative required reserve for lines of credit. This method contains several different underlying calculations including average annual loss rate, pay-down rate, cumulative loss, average draw , and undrawn liability reserve. The vintage loss rate method calculates annual loss rates by origination year. The results of this model are then applied to outstanding balances, which correspond to the origination period for each annual loss rate. In addition to the risk characteristics noted above, management considers the portion of acquired loans to the overall segment balance, as well as current delinquency and charge-off trends compared to historical time periods. Loans that do not share risk characteristics are evaluated on an individual basis. Loans evaluated individually are not also included in the collective evaluation. When management determines that foreclosure is probable or when the borrower is experiencing financial difficulty at the reporting date and repayment is expected to be provided substantially through the operation or sale of the collateral, expected credit losses are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. Expected credit losses are estimated over the contractual term of the loans and adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals, and modifications unless management has a reasonable expectation at the reporting date that a troubled debt restructuring will be executed with an individual borrower or the extension or renewal options are included in the original or modified contract at the reporting date and are not unconditionally cancellable by the Company. Certain business lending, consumer direct, and home equity loans do not have stated maturities. In determining the estimated life of these loans, management estimates the future cash flows expected to be received and then applies those expected future cash flows to the balance. Expected credit losses for lines of credit with no stated maturity are determined by estimating the amount and timing of all principal payments expected to be received after the reporting period and allocating those principal payments between the balance outstanding as of the reporting period and the balance of future receivables expected to be originated through subsequent usage of the unconditionally cancellable loan commitment associated with the account until the expected payments have been fully allocated. An additional allowance for credit loss is recorded for the excess of the balance outstanding as of the reporting period over the expected principal payments allocated to that balance. Troubled Debt Restructuring A loan for which the terms have been modified resulting in a concession, and for which the borrower is experiencing financial difficulties, is considered to be a troubled debt restructuring (“TDR”). The allowance for credit loss on a TDR is measured using the same method as all other loans, except when the value of a concession cannot be measured using a method other than the discounted cash flow method. When the value of a concession is measured using the discounted cash flow method, the allowance for credit loss is determined by discounting the expected future cash flows at the original interest rate of the loan. Allowance for Credit Losses – Off-balance-sheet credit exposures The Company estimates expected credit losses over the contractual period in which the Company is exposed to credit risk via a contractual obligation to extend credit, unless that obligation is unconditionally cancellable by the Company. There are unfunded commitments for lines of credit within each of the Company’s loan portfolio segments except consumer indirect. The allowance for credit losses on off-balance-sheet credit exposures is adjusted as a provision for (or reversal of) credit loss expense. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated life. Management estimates the allowance balance using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. Historical credit loss experience provides the basis for the estimation of expected credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics that are the same as the adjustments considered for the loan portfolio. Purchased Credit Deteriorated (PCD) Loans The Company has purchased loans, some of which have experienced more than insignificant credit deterioration since origination. The Company’s policy for reviewing what meets the threshold of the definition of a more than insignificant credit deterioration includes loans that are delinquent more than days, loans that have historical delinquencies of more than days at least times since origination, risk rating downgrades since origination, loans with multiple payment deferrals, loans considered to be troubled debt restructurings, specifically impaired loans or loans with certain documented policy exceptions, further refined based on loan-specific facts and circumstances. PCD loans are initially recorded at the amount paid. An allowance for credit losses is determined using the same methodology as other loans. The initial allowance for credit losses determined on a collective basis is allocated to individual loans. The sum of the loan’s purchase price and allowance for credit losses becomes its initial amortized cost basis. The difference between the initial amortized cost basis and the par value of the loan is a noncredit discount or premium, which is amortized into interest income over the life of the loan. Subsequent changes to the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. 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 March of accounts receivable, including of unbilled fee revenue, and of unearned revenue was recorded in the consolidated statements of condition. As of December of accounts receivable, including of unbilled fee revenue, and of unearned revenue was recorded in the consolidated statements of condition. Recently Adopted Accounting Pronouncements In June the FASB issued ASU No. - Financial Instruments – Credit Losses (Topic 326) (“ASU No. - ”). This new guidance significantly changes how entities measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. This ASU replaces the incurred loss methodology with a current expected credit loss (“CECL”) methodology for instruments measured at amortized cost, and requires entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount, as they do under the other-than-temporary impairment model. CECL simplifies the accounting model for purchased credit-impaired debt securities and loans and also applies to off-balance-sheet credit exposures not accounted for as insurance. CECL requires adoption through a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period in which the guidance is adopted. This new guidance is effective for fiscal years beginning after December including interim periods within those fiscal years. The Company adopted ASC on January using a modified retrospective approach for all financial assets measured at amortized cost and off-balance-sheet credit exposures. Results for reporting periods beginning after January are presented under ASC while prior period amounts continue to be reported in accordance with previously applicable GAAP. The Company recorded a net cumulative-effect adjustment that increased retained earnings by . This adjustment was a result of a increase in the allowance for credit losses and a adjustment to loans, partially offset by a increase in other liabilities related to the allowance for off-balance-sheet credit exposures. The adoption of ASU No. - did not result in a material allowance for credit losses on the Company’s available-for-sale debt securities or its other instruments carried at amortized cost. The Company’s regulators will permit financial institutions to “phase-in” the impact of CECL on its regulatory capital ratios for up to 5 years with transitional relief of incremental capital requirements. The Company has not utilized the phased-in approach and recorded the entire cumulative-effect adjustment against its regulatory capital at the time of adoption. The Company adopted ASC using the prospective transition approach for financial assets purchased with credit deterioration (“PCD”) that were previously classified as purchased credit impaired (“PCI”) and accounted for under ASC - In accordance with this standard, management did not reassess whether PCI assets met the criteria of PCD assets as of the date of adoption. On January the amortized cost basis of the PCD assets were adjusted to reflect the addition of of the allowance for credit losses. The remaining noncredit discount (based on the adjusted amortized cost basis) will be accreted into interest income at the effective interest rate beginning on January In January the FASB issued ASU No. - Intangibles-Goodwill and Other (Topic 350) . The amendments simplify how an entity is required to test goodwill for impairment by eliminating the requirement to measure a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Instead, an entity will perform its goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and recognize an impairment charge for the amount by which the carrying amount of the reporting unit exceeds its fair value. Impairment loss recognized under this new guidance will be limited to the goodwill allocated to the reporting unit. This ASU is effective prospectively for the Company for annual or interim goodwill impairment tests in fiscal years beginning after December The Company adopted this guidance on January and determined the adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. In August the FASB issued ASU No. - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurements (Topic 820) . The updated guidance removed the requirement to disclose the amount of and reasons for transfers between Level and Level of the fair value hierarchy, the policy for timing of transfers between levels of the fair value hierarchy, and the valuation processes for Level fair value measurements. The updated guidance clarifies that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurements as of the reporting date. Further, the updated guidance requires disclosure of changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level fair value measurements held at the end of the reporting period and how the weighted average of significant unobservable inputs used to develop Level fair value measurements was calculated. This new guidance is effective for fiscal years beginning after December including interim periods within those fiscal years. The Company adopted this guidance on January and determined the adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. New Accounting Pronouncements In August the FASB issued ASU No. - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans (Subtopic 715 - 20) . The updated guidance removed the requirements to identify amounts that are expected to be reclassified out of accumulated other comprehensive income and recognized as components of net periodic benefit cost in the next fiscal year, as well as the effects of a -percentage-point change in assumed health care cost trend rates on service and interest cost and on the postretirement benefit obligation. The updated guidance added disclosure requirements for the weighted-average interest crediting rates for cash balance plans and other plans with interest crediting rates, and explanations for significant gains and losses related to changes in the benefit obligation for the period. This new guidance is effective retrospectively for fiscal years beginning after December with early adoption permitted. The Company is currently evaluating the impacts the adoption of this guidance will have on the Company’s consolidated financial statements. In December the FASB issued ASU No. - Simplifying the Accounting for Income Taxes (Topic 740) . The updated guidance simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic and clarifying and amending existing guidance to improve consistent application. This new guidance is effective for fiscal years beginning after December including interim periods within those fiscal years. Early adoption is permitted in any interim periods for which financial statements have not been issued. The Company is currently evaluating the impact the adoption of this guidance will have on the Company’s consolidated financial statements.

INVESTMENT SECURITIES

INVESTMENT SECURITIES	3 Months Ended
	Mar. 31, 2020
INVESTMENT SECURITIES [Abstract]
INVESTMENT SECURITIES	NOTE D: INVESTMENT SECURITIES The amortized cost and estimated fair value of investment securities as of March 31, 2020 and December 31, 2019 are as follows: March 31, 2020 December 31, 2019 (000's omitted) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-Sale Portfolio: U.S. Treasury and agency securities $ 2,016,500 $ 122,579 $ 0 $ 2,139,079 $ 2,030,060 $ 21,674 $ 7,975 $ 2,043,759 Obligations of state and political subdivisions 485,755 15,955 2 501,708 497,852 14,382 26 512,208 Government agency mortgage-backed securities 433,129 15,129 10 448,248 428,491 5,478 1,107 432,862 Corporate debt securities 2,512 0 4 2,508 2,527 1 0 2,528 Government agency collateralized mortgage obligations 48,681 1,658 0 50,339 52,621 482 32 53,071 Total available-for-sale portfolio $ 2,986,577 $ 155,321 $ 16 $ 3,141,882 $ 3,011,551 $ 42,017 $ 9,140 $ 3,044,428 Equity and other Securities: Equity securities, at fair value $ 251 $ 198 $ 28 $ 421 $ 251 $ 200 $ 0 $ 451 Federal Home Loan Bank common stock 6,857 0 0 6,857 7,246 0 0 7,246 Federal Reserve Bank common stock 30,922 0 0 30,922 30,922 0 0 30,922 Other equity securities, at adjusted cost 4,549 750 0 5,299 4,546 750 0 5,296 Total equity and other securities $ 42,579 $ 948 $ 28 $ 43,499 $ 42,965 $ 950 $ 0 $ 43,915 A summary of investment securities that have been in a continuous unrealized loss position is as follows: As of March 31, 2020 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: Obligations of state and political subdivisions 9 $ 1,444 $ 2 0 $ 0 $ 0 9 $ 1,444 $ 2 Government agency mortgage-backed securities 1 1,154 10 3 304 0 4 1,458 10 Corporate debt securities 1 2,508 4 0 0 0 1 2,508 4 Government agency collateralized mortgage obligations 0 0 0 2 27 0 2 27 0 Total available-for-sale investment portfolio 11 $ 5,106 $ 16 5 $ 331 $ 0 16 $ 5,437 $ 16 Equity and other Securities: Equity securities, at fair value 1 $ 73 $ 28 0 $ 0 $ 0 1 $ 73 $ 28 Total equity and other securities 1 $ 73 $ 28 0 $ 0 $ 0 1 $ 73 $ 28 As of December 31, 2019 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 12 $ 592,678 $ 7,970 5 $ 25,998 $ 5 17 $ 618,676 $ 7,975 Obligations of state and political subdivisions 21 22,716 26 0 0 0 21 22,716 26 Government agency mortgage-backed securities 50 89,237 341 52 52,975 766 102 142,212 1,107 Government agency collateralized mortgage obligations 5 5,971 14 5 4,405 18 10 10,376 32 Total available-for-sale investment portfolio 88 $ 710,602 $ 8,351 62 $ 83,378 $ 789 150 $ 793,980 $ 9,140 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 ary level of credit enhancement. The Company holds corporate debt security which is currently rated A- or better and the issuer of the security shows no material negative trends over the last five quarters. 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. Timely principal and interest payments continue to be made on the securities. 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 March represents credit losses and no unrealized losses have been recognized into credit loss expense. Accordingly, there is allowance for credit losses on the Company’s available-for-sale portfolio as of March 31, 2020. As of December 31, 2019, management does not believe any individual unrealized loss represents other-than-temporary impairment. The amortized cost and estimated fair value of debt securities at March 31, 2020, 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 $ 662,404 $ 671,422 Due after one through five years 893,934 940,096 Due after five years through ten years 445,987 485,140 Due after ten years 502,442 546,637 Subtotal 2,504,767 2,643,295 Government agency mortgage-backed securities 433,129 448,248 Government agency collateralized mortgage obligations 48,681 50,339 Total $ 2,986,577 $ 3,141,882 As of March 31, 2020, $215.8 million of U.S. Treasury securities were pledged as collateral for securities sold under agreement to repurchase. All securities sold under agreement to repurchase as of March 31, 2020 have an overnight and continuous maturity.

LOANS

LOANS	3 Months Ended
	Mar. 31, 2020
LOANS [Abstract]
LOANS	NOTE E: LOANS The segments of the Company’s loan portfolio are summarized as follows: (000's omitted) March 31, 2020 December 31, 2019 Business lending $ 2,789,130 $ 2,775,876 Consumer mortgage 2,424,656 2,430,902 Consumer indirect 1,087,879 1,113,062 Consumer direct 177,844 184,378 Home equity 386,583 386,325 Gross loans, including deferred origination costs 6,866,092 6,890,543 Allowance for credit losses (55,652 ) (49,911 ) Loans, net of allowance for credit losses $ 6,810,440 $ 6,840,632 The following table presents the aging of the amortized cost basis of the Company’s past due loans, by class as of March 31, 2020: (000’s omitted) Past Due 30 – 89 Days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Purchased Credit Deteriorated (“PCD”) (1) Current Total Loans Business lending $ 13,157 $ 10,111 $ 4,394 $ 27,662 $ 9,781 $ 2,751,687 $ 2,789,130 Consumer mortgage 15,614 1,821 12,674 30,109 0 2,394,547 2,424,656 Consumer indirect 11,343 418 0 11,761 0 1,076,118 1,087,879 Consumer direct 1,197 62 52 1,311 0 176,533 177,844 Home equity 2,951 324 1,926 5,201 0 381,382 386,583 Total $ 44,262 $ 12,736 $ 19,046 $ 76,044 $ 9,781 $ 6,780,267 $ 6,866,092 (1) PCD loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 326-10. As a result, the noncredit discount, after the adjustment for the allowance for credit losses, is being accreted into interest income on all PCD loans. The following is an aged analysis of the Company’s past due loans by class as of December 31, 2019: 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 $ 3,936 $ 126 $ 3,840 $ 7,902 $ 1,848,683 $ 1,856,585 Consumer mortgage 10,990 2,052 10,131 23,173 1,973,543 1,996,716 Consumer indirect 12,673 125 0 12,798 1,094,510 1,107,308 Consumer direct 1,455 76 0 1,531 174,445 175,976 Home equity 1,508 328 1,444 3,280 310,727 314,007 Total $ 30,562 $ 2,707 $ 15,415 $ 48,684 $ 5,401,908 $ 5,450,592 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 $ 8,518 $ 2,173 $ 570 $ 11,261 $ 11,797 $ 896,233 $ 919,291 Consumer mortgage 890 277 2,386 3,553 0 430,633 434,186 Consumer indirect 79 31 0 110 0 5,644 5,754 Consumer direct 59 0 52 111 0 8,291 8,402 Home equity 744 238 412 1,394 0 70,924 72,318 Total $ 10,290 $ 2,719 $ 3,420 $ 16,429 $ 11,797 $ 1,411,725 $ 1,439,951 (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 delinquency status for loans on payment deferment due to COVID-19 financial hardship were reported at March 31, 2020 based on their delinquency status as of March 20, 2020, the date most borrowers were impacted by COVID-19 due to stay at home orders in various states. No interest income on nonaccrual loans was recognized during the three months ended March 31, 2020. An immaterial amount of accrued interest was written off on nonaccrual loans by reversing interest income. 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. Loss may be incurred at some future date, if conditions deteriorate further. Classified The condition of the borrower has significantly deteriorated and the performance of the loan could further deteriorate and incur loss, 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 and loss is likely. The following tables show the amount of business lending loans by credit quality category at March 31, 2020 and December 31, 2019: (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year March 31, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Business lending: Risk rating Pass $ 81,301 $ 386,281 $ 333,585 $ 239,020 $ 276,171 $ 606,390 $ 593,830 $ 2,516,578 Special mention 4,128 12,290 6,887 13,213 4,516 52,457 31,223 124,714 Classified 665 1,933 17,241 9,993 12,790 59,750 45,466 147,838 Doubtful 0 0 0 0 0 0 0 0 Total business lending $ 86,094 $ 400,504 $ 357,713 $ 262,226 $ 293,477 $ 718,597 $ 670,519 $ 2,789,130 December 31, 2019 (000’s omitted) Legacy Acquired Total Pass $ 1,655,280 $ 832,693 $ 2,487,973 Special mention 98,953 45,324 144,277 Classified 102,352 29,477 131,829 Doubtful 0 0 0 Acquired impaired 0 11,797 11,797 Total $ 1,856,585 $ 919,291 $ 2,775,876 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 loans classified as current as well as those classified as - days past due. Nonperforming loans include + days past due and still accruing and nonaccrual loans. The following table details the balances in all other loan categories at March : (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year March 31, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Consumer mortgage: FICO AB Risk rating Performing $ 47,527 $ 252,841 $ 194,612 $ 190,316 $ 187,254 $ 651,314 $ 0 $ 1,523,864 Nonperforming 0 0 153 299 193 2,862 0 3,507 Total FICO AB 47,527 252,841 194,765 190,615 187,447 654,176 0 1,527,371 FICO CDE Risk rating Performing 22,589 111,126 89,451 88,630 94,419 467,433 12,649 886,297 Nonperforming 0 0 142 524 1,327 8,995 0 10,988 Total FICO CDE 22,589 111,126 89,593 89,154 95,746 476,428 12,649 897,285 Total consumer mortgage $ 70,116 $ 363,967 $ 284,358 $ 279,769 $ 283,193 $ 1,130,604 $ 12,649 $ 2,424,656 Consumer indirect: Risk rating Performing $ 74,581 $ 397,442 $ 284,899 $ 133,402 $ 102,849 $ 94,288 $ 0 $ 1,087,461 Nonperforming 0 98 78 63 99 80 0 418 Total consumer indirect $ 74,581 $ 397,540 $ 284,977 $ 133,465 $ 102,948 $ 94,368 0 $ 1,087,879 Consumer direct: Risk rating Performing $ 20,080 $ 66,306 $ 42,399 $ 21,144 $ 11,049 $ 9,121 $ 7,631 $ 177,730 Nonperforming 0 14 1 66 3 0 30 114 Total consumer direct $ 20,080 $ 66,320 $ 42,400 $ 21,210 $ 11,052 $ 9,121 $ 7,661 $ 177,844 Home equity: Risk rating Performing $ 14,521 $ 51,149 $ 28,687 $ 23,194 $ 19,318 $ 35,395 $ 212,069 $ 384,333 Nonperforming 0 0 0 73 118 461 1,598 2,250 Total home equity $ 14,521 $ 51,149 $ 28,687 $ 23,267 $ 19,436 $ 35,856 $ 213,667 $ 386,583 The following table details the balances in all other loan categories at December 31, 2019: Legacy Loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 1,984,533 $ 1,107,183 $ 175,900 $ 312,235 $ 3,579,851 Nonperforming 12,183 125 76 1,772 14,156 Total $ 1,996,716 $ 1,107,308 $ 175,976 $ 314,007 $ 3,594,007 Acquired Loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 431,523 $ 5,723 $ 8,350 $ 71,668 $ 517,264 Nonperforming 2,663 31 52 650 3,396 Total $ 434,186 $ 5,754 $ 8,402 $ 72,318 $ 520,660 All loan classes are collectively evaluated for impairment except business lending. A summary of individually evaluated impaired business loans as of March 31, 2020 and December 31, 2019 follows: (000’s omitted) March 31, 2020 December 31, 2019 Loans with allowance allocation $ 0 $ 0 Loans without allowance allocation 1,771 1,414 Carrying balance 1,771 1,414 Contractual balance 3,305 2,944 Specifically allocated allowance 0 0 The average carrying balance of individually evaluated impaired loans was $2.2 million and $6.2 million for the three months ended March 31, 2020 and March 31, 2019, respectively. No interest income was recognized on individually evaluated impaired loans for the three months ended March 31, 2020 and March 31, 2019. 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. In accordance with the clarified guidance issued by the Office of the Comptroller of the Currency (“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 the three months ended March 31, 2020 and 2019 was immaterial. TDRs that are less than $0.5 million are collectively included in the allowance for credit loss estimate. TDRs that are commercial loans and greater than $0.5 million are individually evaluated for impairment, and if necessary, a specific allocation of the allowance for credit losses is provided. As a result, the determination of the amount of allowance for credit losses related to TDRs is the same as detailed in the critical accounting policies. With respect to the Company’s lending activities, the Company implemented a customer payment deferral program for deferrals up to three months during the first quarter of 2020 to assist both consumer and business borrowers that may be experiencing financial hardship due to COVID-19 related challenges. Business lending, consumer direct, and consumer indirect loans in deferment status will continue to accrue interest on the deferred principal during the deferment period unless otherwise classified as nonaccrual. Consumer mortgage and home equity loans will not accrue interest on the deferred payments during the deferment period. Consistent with industry regulatory guidance, borrowers that were otherwise current on loan payments that were granted COVID-19 related financial hardship payment deferrals will continue to be reported as current loans throughout the agreed upon deferral period. These payment deferrals were also deemed to be an insignificant borrower concession, and therefore, not classified as troubled-debt restructured loans during the first quarter. Borrowers that were delinquent in their payments to the Bank, prior to requesting a COVID-19 related financial hardship payment deferral were reviewed on a case by case basis for troubled debt restructure classification and non-performing loan status. Information regarding TDRs as of March 31, 2020 and December 31, 2019 is as follows: March 31, 2020 December 31, 2019 (000’s omitted) Nonaccrual Accruing Total Nonaccrual Accruing Total # Amount # Amount # Amount # Amount # Amount # Amount Business lending 8 $ 644 3 $ 197 11 $ 841 8 $ 681 3 $ 201 11 $ 882 Consumer mortgage 60 2,646 47 2,160 107 4,806 59 2,638 47 1,892 106 4,530 Consumer indirect 0 0 89 935 89 935 0 0 84 941 84 941 Consumer direct 0 0 23 106 23 106 0 0 23 101 23 101 Home equity 13 298 11 233 24 531 13 290 11 238 24 528 Total 81 $ 3,588 173 $ 3,631 254 $ 7,219 80 $ 3,609 168 $ 3,373 248 $ 6,982 The following table presents information related to loans modified in a TDR during the three months ended March 31, 2020 and 2019. Of the loans noted in the table below, all consumer mortgage loans for the three months ended March 31, 2020 and 2019 were modified due to a Chapter 7 bankruptcy as described previously. The financial effects of these restructurings were immaterial Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 (000’s omitted) Number of loans modified Outstanding Balance Number of loans modified Outstanding Balance Business lending 0 $ 0 0 $ 0 Consumer mortgage 7 617 8 665 Consumer indirect 14 127 11 98 Consumer direct 1 12 0 0 Home equity 0 0 1 4 Total 22 $ 756 20 $ 767 Allowance for Credit Losses The following presents by segment the activity in the allowance for credit losses: Three Months Ended March 31, 2020 (000’s omitted) Beginning balance, prior to the adoption of ASC 326 Impact of ASC 326 Beginning balance, after adoption of ASC 326 Charge-offs Recoveries Provision Ending balance Business lending $ 19,426 $ 288 $ 19,714 $ (176 ) $ 138 $ (187 ) $ 19,489 Consumer mortgage 10,269 (1,051 ) 9,218 (186 ) 8 3,390 12,430 Consumer indirect 13,712 (997 ) 12,715 (2,079 ) 1,163 1,895 13,694 Consumer direct 3,255 (643 ) 2,612 (533 ) 182 1,476 3,737 Home equity 2,129 808 2,937 (73 ) 6 (386 ) 2,484 Unallocated 957 43 1,000 0 0 (228 ) 772 Purchased credit deteriorated 0 3,072 3,072 0 0 (26 ) 3,046 Purchased credit impaired 163 (163 ) 0 0 0 0 0 Allowance for credit losses – loans 49,911 1,357 51,268 (3,047 ) 1,497 5,934 55,652 Liabilities for off-balance-sheet credit exposures 0 1,185 1,185 0 0 (340 ) 845 Total allowance for credit losses $ 49,911 $ 2,542 $ 52,453 $ (3,047 ) $ 1,497 $ 5,594 $ 56,497 Three Months Ended March 31, 2019 (000’s omitted) Business Lending Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Unallocated Acquired Impaired Total Beginning balance $ 18,522 $ 10,124 $ 14,366 $ 3,095 $ 2,144 $ 1,000 $ 33 $ 49,284 Charge-offs (1,216 ) (253 ) (1,823 ) (535 ) (74 ) 0 0 (3,901 ) Recoveries 134 22 962 179 5 0 0 1,302 Provision 831 424 746 317 (8 ) (10 ) 122 2,422 Ending balance $ 18,271 $ 10,317 $ 14,251 $ 3,056 $ 2,067 $ 990 $ 155 $ 49,107 The decline in economic conditions associated with the COVID-19 pandemic have resulted in an allowance for credit losses to total loans ratio of 0.81% at March 31, 2020, three basis points higher than the level at March 31, 2019 and nine basis points higher than the level at December 31, 2019. Under CECL, the Company utilizes the historical loss rate on its loan portfolio as the initial basis for the estimate of credit losses using the cumulative loss, vintage loss and line loss methods which is derived from the Company’s historical loss experience from January 1, 2012 to December 31, 2019. Adjustments to historical loss experience were made for differences in current loan-specific risk characteristics and to address current period delinquencies, charge-off rates, risk ratings, lack of loan level data through an entire economic cycle, changes in loan sizes and underwriting standards as well as the addition of acquired loans which were not underwritten by the Company. The Company considered historical losses immediately prior, through and following the Great Recession of 2008 compared to the historical period used for modeling to adjust the historical information to account for longer-term expectations for loan credit performance. Under CECL, the Company is required to consider future economic conditions to determine expected losses under a life of loan concept. Management selected an eight quarter reasonable and supportable forecast period with a four quarter reversion to the historical mean to use as part of the economic forecast. Management determined that these qualitative adjustments were needed to adjust historical information to reflect changes as a result of current conditions. The Company uses third party forecasted economic data scenarios utilizing a base scenario and two alternative scenarios that were weighted based on guidance from the third party provider, with forecasts available as of March 31, 2020. These forecasts included the impact of COVID-19 and were factored into the qualitative portion of the calculation of the estimated credit losses. The scenarios utilized outline an immediate and precipitous decrease in economic activity in the second quarter of 2020 with peak unemployment ranging from 8% to 13% in that quarter and a general improvement in unemployment levels over the subsequent seven quarters. In addition to the economic forecast, the Company also considered additional qualitative adjustments as a result of COVID-19 and the impact on all industries, loan deferrals, delinquencies and downgrades, the Paycheck Protection Program and the Federal stimulus package. Management developed expected loss estimates considering factors for segments as outlined below: • Business lending – non real estate: The Company considered projected unemployment and GDP as possible indicators of forecasted losses related to business lending. The Company also considered delinquencies, risk rating changes, recent charge-off history and acquired loans as part of the review of estimated losses. • Business lending – real estate: The Company considered projected real estate values as possible indicators of forecasted losses related to commercial real estate loans in addition to the factors noted in business lending – non real estate. • Consumer mortgages and home equity: The Company considered projected unemployment and real estate values as possible indicators of forecasted losses related to mortgage lending. In addition, current delinquencies, charge-offs and acquired loans were considered. • Consumer indirect: The Company considered projected unemployment and vehicle valuation indices as possible indicators of forecasted losses related to indirect lending. In addition, current delinquencies, charge-offs and acquired loans were considered. • Consumer direct: The Company considered projected unemployment as a possible indicator of forecasted losses related to direct lending. In addition, current delinquencies, charge-offs and acquired loans were considered.

GOODWILL AND IDENTIFIABLE INTAN

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2020
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: March 31, 2020 December 31, 2019 (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 $ 66,475 $ (51,474 ) $ 15,001 $ 66,475 $ (50,057 ) $ 16,418 Other intangibles 89,266 (44,821 ) 44,445 89,266 (42,571 ) 46,695 Total amortizing intangibles $ 155,741 $ (96,295 ) $ 59,446 $ 155,741 $ (92,628 ) $ 63,113 The estimated aggregate amortization expense for each of the five succeeding fiscal years ended December 31 is as follows: (000's omitted) Apr - Dec 2020 $ 10,133 2021 11,786 2022 10,105 2023 8,457 2024 7,041 Thereafter 11,924 Total $ 59,446 Shown below are the components of the Company’s goodwill at December 31, 2019 and March 31, 2020: (000’s omitted) December 31, 2019 Activity March 31, 2020 Goodwill $ 778,634 $ (337 ) $ 778,297 Accumulated impairment (4,824 ) 0 (4,824 ) Goodwill, net $ 773,810 $ (337 ) $ 773,473

MANDATORILY REDEEMABLE PREFERRE

MANDATORILY REDEEMABLE PREFERRED SECURITIES	3 Months Ended
	Mar. 31, 2020
MANDATORILY REDEEMABLE PREFERRED SECURITIES [Abstract]
MANDATORILY REDEEMABLE PREFERRED SECURITIES	NOTE G: MANDATORILY REDEEMABLE PREFERRED SECURITIES As of March 31, 2020, the Company sponsors business trust, Community Capital Trust IV (“CCT IV”), of which of the common stock is owned by the Company. The Company previously sponsored MBVT Statutory Trust I (“MBVT I”) and Kinderhook Capital Trust (“KCT”) until September when the Company exercised its right to redeem all of the MBVT I and KCT debentures and associated preferred securities for a total of and , respectively. The common stock of MBVT I was acquired in the Merchants Bancshares, Inc. (“Merchants”) acquisition and the common stock of KCT was acquired in the Kinderhook Bank Corp. (“Kinderhook”) acquisition. The trusts were formed for the purpose of issuing company-obligated mandatorily redeemable preferred securities to -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. As of March 31, 2020, the terms of the preferred securities of CCT IV are as follows: Issuance Par Maturity Trust Date Amount Interest Rate Date Call Price CCT IV 12/8/2006 $75.0 million 3 month LIBOR plus 1.65% (2.39%) 12/15/2036 Par

BENEFIT PLANS

BENEFIT PLANS	3 Months Ended
	Mar. 31, 2020
BENEFIT PLANS [Abstract]
BENEFIT PLANS	NOTE H: BENEFIT 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. The Company accrues for the estimated cost of these benefits through charges to expense during the years that employees earn these benefits. The service cost component of net periodic benefit income is included in the salaries and employee benefits line of the consolidated statements of income, while the other components of net periodic benefit income are included in other expenses. The Company made a $7.3 million contribution to its defined benefit pension plan in the first quarter of 2019. The Company did not make a contribution to its defined benefit pension plan in the first quarter of 2020. The net periodic benefit cost for the three months ended March 31, 2020 and 2019 is as follows: Pension Benefits Post-retirement Benefits Three Months Ended March 31, Three Months Ended March 31, (000's omitted) 2020 2019 2020 2019 Service cost $ 1,438 $ 1,270 $ 0 $ 0 Interest cost 1,356 1,566 14 18 Expected return on plan assets (3,932 ) (3,577 ) 0 0 Amortization of unrecognized net loss 810 642 10 9 Amortization of prior service cost 60 16 (45 ) (45 ) Net periodic benefit $ (268 ) $ (83 ) $ (21 ) $ (18 )

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2020
EARNINGS PER SHARE [Abstract]
EARNINGS PER SHARE	NOTE I: 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 March 31, 2020. 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 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 0.2 million weighted-average anti-dilutive stock options outstanding for the three months ended March 31, 2020, compared to approximately 0.5 million weighted-average anti-dilutive stock options outstanding for the three months ended March 31, 2019 that were not included in the computation below. The following is a reconciliation of basic to diluted earnings per share for the three months ended March 31, 2020 and 2019: Three Months Ended March 31, (000's omitted, except per share data) 2020 2019 Net income $ 40,134 $ 41,946 Income attributable to unvested stock-based compensation awards (146 ) (109 ) Income available to common shareholders $ 39,988 $ 41,837 Weighted-average common shares outstanding – basic 52,036 51,520 Basic earnings per share $ 0.77 $ 0.81 Net income $ 40,134 $ 41,946 Income attributable to unvested stock-based compensation awards (146 ) (109 ) Income available to common shareholders $ 39,988 $ 41,837 Weighted-average common shares outstanding – basic 52,036 51,520 Assumed exercise of stock options 420 541 Weighted-average common shares outstanding – diluted 52,456 52,061 Diluted earnings per share $ 0.76 $ 0.80 Stock Repurchase Program At its December 2018 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, 2019. At its December 2019 meeting, the Board approved a similar program for 2020, authorizing the repurchase of up to 2.6 million shares of the Company’s common stock through December 31, 2020. 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. The Company did not repurchase any shares under the authorized plan during the first three months of 2020 or 2019.

COMMITMENTS, CONTINGENT LIABILI

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS	3 Months Ended
	Mar. 31, 2020
COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS [Abstract]
COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS	NOTE J: 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: (000's omitted) March 31, 2020 December 31, 2019 Commitments to extend credit $ 1,033,133 $ 1,143,780 Standby letters of credit 39,284 37,872 Total $ 1,072,417 $ 1,181,652 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 March 31, 2020, 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 believed to be 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.

FAIR VALUE

FAIR VALUE	3 Months Ended
	Mar. 31, 2020
FAIR VALUE [Abstract]
FAIR VALUE	NOTE K: FAIR VALUE 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. March 31, 2020 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,986,718 $ 152,361 $ 0 $ 2,139,079 Obligations of state and political subdivisions 0 501,708 0 501,708 Government agency mortgage-backed securities 0 448,248 0 448,248 Corporate debt securities 0 2,508 0 2,508 Government agency collateralized mortgage obligations 0 50,339 0 50,339 Total available-for-sale investment securities 1,986,718 1,155,164 0 3,141,882 Equity securities 421 0 0 421 Mortgage loans held for sale 0 3,272 0 3,272 Commitments to originate real estate loans for sale 0 0 530 530 Forward sales commitments 0 26 0 26 Interest rate swap agreements asset 0 1,825 0 1,825 Interest rate swap agreements liability 0 (1,261 ) 0 (1,261 ) Total $ 1,987,139 $ 1,159,026 $ 530 $ 3,146,695 December 31, 2019 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,878,705 $ 165,054 $ 0 $ 2,043,759 Obligations of state and political subdivisions 0 512,208 0 512,208 Government agency mortgage-backed securities 0 432,862 0 432,862 Corporate debt securities 0 2,528 0 2,528 Government agency collateralized mortgage obligations 0 53,071 0 53,071 Total available-for-sale investment securities 1,878,705 1,165,723 0 3,044,428 Equity securities 451 0 0 451 Interest rate swap agreements asset 0 851 0 851 Interest rate swap agreements liability 0 (586 ) 0 (586 ) Total $ 1,879,156 $ 1,165,988 $ 0 $ 3,045,144 The valuation techniques used to measure fair value for the items in the table above are as follows: • Available-for-sale investment securities and equity securities – The fair values of available-for-sale investment securities are 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 D for further disclosure of the fair value of investment securities. • Mortgage loans held for sale – The Company has elected to value 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. The fair value of mortgage loans held for sale is determined using quoted secondary-market prices of loans with similar characteristics and, as such, has been classified as a Level 2 valuation. The unpaid principal value of mortgage loans held for sale was approximately $3.0 million at March 31, 2020. The Company did not have any mortgage loans held for sale at December 31, 2019. The unrealized gain on mortgage loans held for sale was recognized in mortgage banking revenues in the consolidated statements of income and is 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 swaps – The interest rate swaps are reported at their fair value utilizing Level 2 inputs from third parties. The fair value of the 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. The fair value information of assets and liabilities measured on a non-recurring basis presented below is not as of the period-end, but rather as of the date the fair value adjustment was recorded closest to the date presented. March 31, 2020 December 31, 2019 (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 $ 848 $ 848 $ 0 $ 0 $ 848 $ 848 Other real estate owned 0 0 1,469 1,469 0 0 1,270 1,270 Mortgage servicing rights 0 0 52 52 0 0 56 56 Total $ 0 $ 0 $ 2,369 $ 2,369 $ 0 $ 0 $ 2,174 $ 2,174 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 loan 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 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 9.0% to 85.7% at March 31, 2020 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 a valuation allowance of approximately $ million 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. The significant unobservable inputs used in the determination of fair value of assets classified as Level 3 on a recurring or non-recurring basis are as follows: (000's omitted) Fair Value at March 31, 2020 Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Impaired loans $ 848 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 35.0% (27.9 %) Other real estate owned 1,469 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 85.7% (35.5 %) Commitments to originate real estate loans for sale 530 Discounted cash flow Embedded servicing value 1 % Mortgage servicing rights 52 Discounted cash flow Weighted average constant prepayment rate 43.0 % Weighted average discount rate 1.90 % Adequate compensation $7/loan (000's omitted) Fair Value at December 31, 2019 Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Impaired loans $ 848 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 35.0% (27.9 %) Other real estate owned 1,270 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 85.7% (37.1 %) Mortgage servicing rights 56 Discounted cash flow Weighted average constant prepayment rate 52.8 % Weighted average discount rate 3.00 % Adequate compensation $7/loan The significant unobservable inputs used in the determination of the fair value of assets classified as Level 3 have an inherent measurement uncertainty that if changed could result in higher or lower fair value measurements of these assets as of the reporting date. The weighted average of the estimated cost of disposal/market adjustment for impaired loans was calculated by dividing the total of the book value of the collateral of the impaired loans classified as Level 3 by the total of the fair value of the collateral of the impaired loans classified as Level 3. The weighted average of the estimated cost of disposal/market adjustment for other real estate owned was calculated by dividing the total of the differences between the appraisal values of the real estate and the book values of the real estate divided by the totals of the appraisal values of the real estate. 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 March 31, 2020 and December 31, 2019 are as follows: March 31, 2020 December 31, 2019 (000's omitted) Carrying Value Fair Value Carrying Value Fair Value Financial assets: Net loans $ 6,810,440 $ 7,063,785 $ 6,840,632 $ 7,028,663 Financial liabilities: Deposits 9,303,982 9,319,783 8,994,967 8,997,551 Overnight Federal Home Loan Bank borrowings 0 0 8,300 8,300 Securities sold under agreement to repurchase, short-term 204,991 204,991 241,708 241,708 Other Federal Home Loan Bank borrowings 3,727 3,789 3,750 3,755 Subordinated notes payable 13,775 13,775 13,795 13,795 Subordinated debt held by unconsolidated subsidiary trusts 77,320 77,320 77,320 77,320 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 short-term borrowings and securities sold under agreement to repurchase, short-term, is the amount payable on demand at the reporting date. Fair values for long-term debt 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	3 Months Ended
	Mar. 31, 2020
DERIVATIVE INSTRUMENTS [Abstract]
DERIVATIVE INSTRUMENTS	NOTE L: 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 March 31, 2020 and December 31, 2019. The effect of the changes to these derivatives for the three months ended March 31, 2020 and March 31, 2019 was also immaterial. The Company acquired interest rate swaps in 2017 with notional amounts with certain commercial customers which totaled $16.0 million at March 31, 2020 and $16.4 million at December 31, 2019. 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 $16.0 million at March 31, 2020 and $16.4 million at December 31, 2019. At March 31, 2020, the weighted average receive rate of these interest rate swaps was 2.88%, the weighted average pay rate was 4.39% and the weighted average maturity was 5.9 years. At December 31, 2019, the weighted average receive rate of these interest rate swaps was 3.72%, the weighted average pay rate was 4.39% and the weighted average maturity was 6.1 years. Hedge accounting has not been applied for these derivatives. Since the terms of the swaps with the Company’s 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 the Company’s results of operations. The Company also acquired interest rate swaps in 2017 with notional amounts totaling $6.2 million at March 31, 2020, and $6.2 million at December 31, 2019, that were designated as fair value hedges of certain fixed rate loans with municipalities which are recorded in loans in the consolidated statements of financial condition. At March 31, 2020, the weighted average receive rate of these interest rate swaps was 1.92%, the weighted average pay rate was 3.11% and the weighted average maturity was 13.3 years. At December 31, 2019, the weighted average receive rate of these interest rate swaps was 2.47%, the weighted average pay rate was 3.11% and the weighted average maturity was 13.5 years. The Company includes the gain or loss on the hedged items in interest and fees on loans, the same line item as the offsetting gain or loss on the related interest rate swaps. The effects of fair value accounting in the consolidated statement of income for the three months ended March 31, 2020 and March 31, 2019 are immaterial. As of March 31, 2020 and December 31, 2019, the following amounts were recorded in the consolidated statement of condition related to cumulative basis adjustments for fair value hedges: (000’s omitted) Line Item in the Consolidated Statement of Condition in Which the Hedged Item Is Included Carrying Amount of the Hedged Assets Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Loans $ 6,091 $ 6,390 $ (564) $ (265) Fair values of derivative instruments as of March 31, 2020 and December 31, 2019 are as follows: (000’s omitted) March 31, 2020 Derivative Assets Derivative Liabilities Consolidated Statement of Condition Location Fair Value Consolidated Statement of Condition Location Fair Value Derivatives designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets $ 564 Derivatives not designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets 1,261 Accrued interest and other liabilities $ 1,261 Commitments to originate real estate loans for sale Other assets 530 Forward sales commitments Other assets 26 Total derivatives $ 2,381 $ 1,261 (000’s omitted) December 31, 2019 Derivative Assets Derivative Liabilities Consolidated Statement of Condition Location Fair Value Consolidated Statement of Condition Location Fair Value Derivatives designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets $ 265 Derivatives not designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets 586 Accrued interest and other liabilities $ 586 Total derivatives $ 851 $ 586 The Company assessed its counterparty risk at March 31, 2020 and December 31, 2019 and determined any credit risk inherent in our derivative contracts was not material. Further information about the fair value of derivative financial instruments can be found in Note K to these consolidated financial statements.

SEGMENT INFORMATION

SEGMENT INFORMATION	3 Months Ended
	Mar. 31, 2020
SEGMENT INFORMATION [Abstract]
SEGMENT INFORMATION	NOTE M: 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. Community Bank, N.A. (the “Bank” or “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 the operating subsidiaries Benefit Plans Administrative Services, LLC, BPAS Actuarial and Pension Services, LLC, BPAS Trust Company of Puerto Rico, Northeast Retirement Services, LLC (“NRS”), Global Trust Company, Inc. (“GTC”), and Hand Benefits & Trust Company, provides employee benefit trust, collective investment fund, retirement plan administration, fund administration, transfer agency, actuarial, VEBA/HRA, and health and welfare consulting services. The All Other segment is comprised of: (a) wealth 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, Inc., as well as asset management provided by Nottingham Advisors, Inc., 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, Summary of Significant Accounting Policies 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 Three Months Ended March 31, 2020 Net interest income $ 89,763 $ 240 $ 51 $ 0 $ 90,054 Provision for credit losses 5,594 0 0 0 5,594 Noninterest revenues 18,680 25,925 15,536 (1,519 ) 58,622 Amortization of intangible assets 1,417 1,494 756 0 3,667 Acquisition expenses 369 0 0 0 369 Other operating expenses 64,200 15,130 11,816 (1,519 ) 89,627 Income before income taxes $ 36,863 $ 9,541 $ 3,015 $ 0 $ 49,419 Assets $ 11,633,330 $ 213,768 $ 76,525 $ (114,640 ) $ 11,808,983 Goodwill $ 669,886 $ 83,275 $ 20,312 $ 0 $ 773,473 Core deposit intangibles & Other intangibles $ 15,001 $ 36,281 $ 8,164 $ 0 $ 59,446 Three Months Ended March 31, 2019 Net interest income $ 86,715 $ 108 $ 36 $ 0 $ 86,859 Provision for credit losses 2,422 0 0 0 2,422 Noninterest revenues 17,348 24,670 14,447 (769 ) 55,696 Amortization of intangible assets 1,483 1,769 878 0 4,130 Acquisition expenses 534 0 0 0 534 Other operating expenses 59,769 14,279 10,709 (769 ) 83,988 Income before income taxes $ 39,855 $ 8,730 $ 2,896 $ 0 $ 51,481 Assets $ 10,699,384 $ 199,345 $ 71,047 $ (53,309 ) $ 10,916,467 Goodwill $ 629,916 $ 83,275 $ 20,312 $ 0 $ 733,503 Core deposit intangibles & Other intangibles $ 17,113 $ 42,777 $ 11,026 $ 0 $ 70,916

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	3 Months Ended
	Mar. 31, 2020
BASIS OF PRESENTATION [Abstract]
Basis of Presentation	The interim financial data as of and for the three months ended March 31, 2020 is unaudited; however, in the opinion of Community Bank System, Inc. (the “Company”), the interim data includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the results for the interim periods in conformity with generally accepted accounting principles in the United States of America (“GAAP”). The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period.

ACCOUNTING POLICIES (Policies)

ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2020
ACCOUNTING POLICIES [Abstract]
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 or through March 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 March or December Equity securities with a readily determinable fair value are reported at fair value with net unrealized gains and losses recognized in the consolidated statements of income. Certain equity securities that do not have a readily determinable fair value are stated at cost, 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.
Allowance for Credit Losses - Debt Securities	Allowance for Credit Losses – Debt Securities For held-to-maturity debt securities, the Company measures expected credit losses on a collective basis by major security type. The estimates of expected credit losses considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. Accrued interest receivable on held-to-maturity securities is excluded from the estimates of credit losses. For available-for-sale debt securities in an unrealized loss position, the Company assesses whether it intends to sell, or it more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through income. For available-for-sale debt securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the security structure, recent security collateral performance metrics, if applicable, external credit ratings, failure of the issuer to make scheduled interest or principal payments, judgment about and expectations of future performance, and relevant independent industry research, analysis, and forecasts. The severity of the impairment and the length of time the security has been impaired is also considered in the assessment. This assessment involves a high degree of subjectivity and judgment that is based on the information available to management at a point in time. If this assessment indicates that a credit loss exists, the present value of the cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected from the security is less than the amortized cost basis of the security, a credit loss exists and an allowance for credit losses is recorded, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. Changes in the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. Losses are charged against the allowance when management believes the uncollectibility of an available-for-sale security is confirmed or when either of the criteria regarding intent or requirement to sell is met. Accrued interest receivable on available-for-sale debt securities, included in accrued interest and fees receivable on the consolidated statements of condition, totaled at March and is excluded from the estimate of credit losses.
Loans	Loans Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at amortized cost, net of allowance for credit losses. Amortized cost is the principal balance outstanding, net of purchase premiums and discounts, and deferred loan fees and costs. 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. Accrued interest receivable on loans, included in accrued interest and fees receivable on the consolidated statements of condition, totaled at March and is excluded from the estimate of credit losses and amortized cost basis of loans. An allowance for credit losses is not measured for accrued interest receivable on loans as the Company writes off the uncollectible accrued interest balance in a timely manner. 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 90 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. 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 Credit Losses - Loans	Allowance for Credit Losses – Loans The allowance for credit losses is a valuation account that is netted against the loans’ amortized cost basis to present the net amount expected to be collected on the loans. Loans are charged off against the allowance when management believes the uncollectibility of a loan balance is confirmed. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off. Management estimates the allowance balance using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. Historical credit loss experience provides the basis for the estimation of expected credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics such as differences in underwriting standards, portfolio mix, acquired loans, delinquency level, risk ratings or term of loans as well as changes in macroeconomic conditions, such as changes in unemployment rates, property values such as home prices, commercial real estate prices and automobile prices, gross domestic product, recession probability, and other relevant factors. The segments of the Company’s loan portfolio are disaggregated into the following classes that allow management to monitor risk and performance: • Business lending is comprised of general purpose commercial and industrial loans including, but not limited to agricultural-related and dealer floor plans, loans to not-for-profit enterprises, as well as mortgages on commercial property. The portfolio segment is further broken into portfolio classes based on risks associated with the collateral supporting the loans. Each class of business lending can also have different payment structures. Business lending loans are generally higher dollar loans and a large portion are risk rated at least annually. • Consumer mortgages consist primarily of fixed rate residential instruments, typically – years in contractual term, secured by liens on real property. FICO scores are used to monitor higher risks related to this type of lending with FICO AB referring to higher tiered loans with FICO scores greater than or equal to 720 as compared to FICO CDE with lower FICO scores less than 720 and potentially higher risk. • Consumer indirect consists primarily of installment loans originated through selected dealerships and are generally secured by automobiles, marine and other recreational vehicles. Collateral securing the loans was used to further disaggregate this portfolio as charge-offs can vary depending on the purpose of the loan. Non-auto loans often have longer terms, and generally have higher risk due to declines in collateral value given the nature of the property. • Consumer direct consists of all other loans to consumers such as personal installment loans and check credit lines of credit. • Home equity products are installment loans or lines of credit most often secured by a or lien position on residential real estate with terms up to years. The allowance for credit losses is measured on a collective (pool) basis when similar risk characteristics exist, including collateral type, credit ratings/scores, size, duration, interest rate structure, industry, geography, origination vintage, and payment structure. The Company has identified the following portfolio segments and classes and measures the allowance for credit losses using the following methods: Loan Portfolio Segment Loan Portfolio Class Allowance for Credit Losses Methodology Business lending Commercial real estate multi family Cumulative loss rate Business lending Commercial real estate non-owner occupied Cumulative loss rate Business lending Commercial real estate owner occupied Cumulative loss rate Business lending Commercial and industrial loans Vintage loss rate Business lending Commercial and industrial lines of credit Line loss Business lending Municipal Cumulative loss rate Business lending Other business Cumulative loss rate Consumer mortgage Consumer mortgage FICO AB Cumulative loss rate Consumer mortgage Consumer mortgage FICO CDE Cumulative loss rate Consumer indirect Indirect new auto Vintage loss rate Consumer indirect Indirect used auto Vintage loss rate Consumer indirect Indirect non-auto Vintage loss rate Consumer direct Consumer check credit Line loss Consumer direct Consumer direct Vintage loss rate Home equity Home equity fixed rate Vintage loss rate Home equity Home equity lines of credit Line loss The cumulative loss rate method uses historical loss data applied against multiple pools of loans and uses a quantitatively based management overlay in order to capture the risk for a loan’s entire expected life. These loss rates are then applied to current balances to achieve a required reserve before qualitative adjustments. The line loss method calculates the quantitative required reserve for lines of credit. This method contains several different underlying calculations including average annual loss rate, pay-down rate, cumulative loss, average draw , and undrawn liability reserve. The vintage loss rate method calculates annual loss rates by origination year. The results of this model are then applied to outstanding balances, which correspond to the origination period for each annual loss rate. In addition to the risk characteristics noted above, management considers the portion of acquired loans to the overall segment balance, as well as current delinquency and charge-off trends compared to historical time periods. Loans that do not share risk characteristics are evaluated on an individual basis. Loans evaluated individually are not also included in the collective evaluation. When management determines that foreclosure is probable or when the borrower is experiencing financial difficulty at the reporting date and repayment is expected to be provided substantially through the operation or sale of the collateral, expected credit losses are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. Expected credit losses are estimated over the contractual term of the loans and adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals, and modifications unless management has a reasonable expectation at the reporting date that a troubled debt restructuring will be executed with an individual borrower or the extension or renewal options are included in the original or modified contract at the reporting date and are not unconditionally cancellable by the Company. Certain business lending, consumer direct, and home equity loans do not have stated maturities. In determining the estimated life of these loans, management estimates the future cash flows expected to be received and then applies those expected future cash flows to the balance. Expected credit losses for lines of credit with no stated maturity are determined by estimating the amount and timing of all principal payments expected to be received after the reporting period and allocating those principal payments between the balance outstanding as of the reporting period and the balance of future receivables expected to be originated through subsequent usage of the unconditionally cancellable loan commitment associated with the account until the expected payments have been fully allocated. An additional allowance for credit loss is recorded for the excess of the balance outstanding as of the reporting period over the expected principal payments allocated to that balance.
Troubled Debt Restructuring	Troubled Debt Restructuring A loan for which the terms have been modified resulting in a concession, and for which the borrower is experiencing financial difficulties, is considered to be a troubled debt restructuring (“TDR”). The allowance for credit loss on a TDR is measured using the same method as all other loans, except when the value of a concession cannot be measured using a method other than the discounted cash flow method. When the value of a concession is measured using the discounted cash flow method, the allowance for credit loss is determined by discounting the expected future cash flows at the original interest rate of the loan.
Allowance for Credit Losses - Off-balance-sheet credit exposures	Allowance for Credit Losses – Off-balance-sheet credit exposures The Company estimates expected credit losses over the contractual period in which the Company is exposed to credit risk via a contractual obligation to extend credit, unless that obligation is unconditionally cancellable by the Company. There are unfunded commitments for lines of credit within each of the Company’s loan portfolio segments except consumer indirect. The allowance for credit losses on off-balance-sheet credit exposures is adjusted as a provision for (or reversal of) credit loss expense. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated life. Management estimates the allowance balance using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. Historical credit loss experience provides the basis for the estimation of expected credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics that are the same as the adjustments considered for the loan portfolio.
Purchased Credit Deteriorated (PCD) Loans	Purchased Credit Deteriorated (PCD) Loans The Company has purchased loans, some of which have experienced more than insignificant credit deterioration since origination. The Company’s policy for reviewing what meets the threshold of the definition of a more than insignificant credit deterioration includes loans that are delinquent more than days, loans that have historical delinquencies of more than days at least times since origination, risk rating downgrades since origination, loans with multiple payment deferrals, loans considered to be troubled debt restructurings, specifically impaired loans or loans with certain documented policy exceptions, further refined based on loan-specific facts and circumstances. PCD loans are initially recorded at the amount paid. An allowance for credit losses is determined using the same methodology as other loans. The initial allowance for credit losses determined on a collective basis is allocated to individual loans. The sum of the loan’s purchase price and allowance for credit losses becomes its initial amortized cost basis. The difference between the initial amortized cost basis and the par value of the loan is a noncredit discount or premium, which is amortized into interest income over the life of the loan. Subsequent changes to the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense.
Contract Balances	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 March of accounts receivable, including of unbilled fee revenue, and of unearned revenue was recorded in the consolidated statements of condition. As of December of accounts receivable, including of unbilled fee revenue, and of unearned revenue was recorded in the consolidated statements of condition.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June the FASB issued ASU No. - Financial Instruments – Credit Losses (Topic 326) (“ASU No. - ”). This new guidance significantly changes how entities measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. This ASU replaces the incurred loss methodology with a current expected credit loss (“CECL”) methodology for instruments measured at amortized cost, and requires entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount, as they do under the other-than-temporary impairment model. CECL simplifies the accounting model for purchased credit-impaired debt securities and loans and also applies to off-balance-sheet credit exposures not accounted for as insurance. CECL requires adoption through a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period in which the guidance is adopted. This new guidance is effective for fiscal years beginning after December including interim periods within those fiscal years. The Company adopted ASC on January using a modified retrospective approach for all financial assets measured at amortized cost and off-balance-sheet credit exposures. Results for reporting periods beginning after January are presented under ASC while prior period amounts continue to be reported in accordance with previously applicable GAAP. The Company recorded a net cumulative-effect adjustment that increased retained earnings by . This adjustment was a result of a increase in the allowance for credit losses and a adjustment to loans, partially offset by a increase in other liabilities related to the allowance for off-balance-sheet credit exposures. The adoption of ASU No. - did not result in a material allowance for credit losses on the Company’s available-for-sale debt securities or its other instruments carried at amortized cost. The Company’s regulators will permit financial institutions to “phase-in” the impact of CECL on its regulatory capital ratios for up to 5 years with transitional relief of incremental capital requirements. The Company has not utilized the phased-in approach and recorded the entire cumulative-effect adjustment against its regulatory capital at the time of adoption. The Company adopted ASC using the prospective transition approach for financial assets purchased with credit deterioration (“PCD”) that were previously classified as purchased credit impaired (“PCI”) and accounted for under ASC - In accordance with this standard, management did not reassess whether PCI assets met the criteria of PCD assets as of the date of adoption. On January the amortized cost basis of the PCD assets were adjusted to reflect the addition of of the allowance for credit losses. The remaining noncredit discount (based on the adjusted amortized cost basis) will be accreted into interest income at the effective interest rate beginning on January In January the FASB issued ASU No. - Intangibles-Goodwill and Other (Topic 350) . The amendments simplify how an entity is required to test goodwill for impairment by eliminating the requirement to measure a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Instead, an entity will perform its goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount, and recognize an impairment charge for the amount by which the carrying amount of the reporting unit exceeds its fair value. Impairment loss recognized under this new guidance will be limited to the goodwill allocated to the reporting unit. This ASU is effective prospectively for the Company for annual or interim goodwill impairment tests in fiscal years beginning after December The Company adopted this guidance on January and determined the adoption of this guidance did not have a material impact on the Company’s consolidated financial statements. In August the FASB issued ASU No. - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurements (Topic 820) . The updated guidance removed the requirement to disclose the amount of and reasons for transfers between Level and Level of the fair value hierarchy, the policy for timing of transfers between levels of the fair value hierarchy, and the valuation processes for Level fair value measurements. The updated guidance clarifies that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurements as of the reporting date. Further, the updated guidance requires disclosure of changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level fair value measurements held at the end of the reporting period and how the weighted average of significant unobservable inputs used to develop Level fair value measurements was calculated. This new guidance is effective for fiscal years beginning after December including interim periods within those fiscal years. The Company adopted this guidance on January and determined the adoption of this guidance did not have a material impact on the Company’s consolidated financial statements.
New Accounting Pronouncements	New Accounting Pronouncements In August the FASB issued ASU No. - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans (Subtopic 715 - 20) . The updated guidance removed the requirements to identify amounts that are expected to be reclassified out of accumulated other comprehensive income and recognized as components of net periodic benefit cost in the next fiscal year, as well as the effects of a -percentage-point change in assumed health care cost trend rates on service and interest cost and on the postretirement benefit obligation. The updated guidance added disclosure requirements for the weighted-average interest crediting rates for cash balance plans and other plans with interest crediting rates, and explanations for significant gains and losses related to changes in the benefit obligation for the period. This new guidance is effective retrospectively for fiscal years beginning after December with early adoption permitted. The Company is currently evaluating the impacts the adoption of this guidance will have on the Company’s consolidated financial statements. In December the FASB issued ASU No. - Simplifying the Accounting for Income Taxes (Topic 740) . The updated guidance simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic and clarifying and amending existing guidance to improve consistent application. This new guidance is effective for fiscal years beginning after December including interim periods within those fiscal years. Early adoption is permitted in any interim periods for which financial statements have not been issued. The Company is currently evaluating the impact the adoption of this guidance will have on the Company’s consolidated financial statements.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	3 Months Ended
	Mar. 31, 2020
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: 2019 (000s omitted) Kinderhook Other (1) Total Consideration paid : Cash $ 93,384 $ 1,650 $ 95,034 Total net consideration paid 93,384 1,650 95,034 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 90,381 0 90,381 Investment securities 39,770 0 39,770 Loans 479,877 0 479,877 Premises and equipment 13,970 0 13,970 Accrued interest and fees receivable 1,130 0 1,130 Other assets 14,109 0 14,109 Core deposit intangibles 3,573 0 3,573 Other intangibles 0 1,650 1,650 Deposits (568,161 ) 0 (568,161 ) Other liabilities (2,922 ) 0 (2,922 ) Other Federal Home Loan Bank borrowings (2,420 ) 0 (2,420 ) Subordinated notes payable (13,831 ) 0 (13,831 ) Subordinated debt held by unconsolidated subsidiary trusts (2,062 ) 0 (2,062 ) Total identifiable assets, net 53,414 1,650 55,064 Goodwill $ 39,970 $ 0 $ 39,970 (1) completed by CISI in 2019.
Loans Acquired	The following is a summary of the loans acquired from Kinderhook at the date of acquisition: (000s omitted) Acquired Impaired Loans Acquired Non-impaired Loans Total Acquired Loans Contractually required principal and interest at acquisition $ 13,350 $ 636,384 $ 649,734 Contractual cash flows not expected to be collected (4,176 ) (5,472 ) (9,648 ) Expected cash flows at acquisition 9,174 630,912 640,086 Interest component of expected cash flows (551 ) (159,658 ) (160,209 ) Fair value of acquired loans $ 8,623 $ 471,254 $ 479,877

INVESTMENT SECURITIES (Tables)

INVESTMENT SECURITIES (Tables)	3 Months Ended
	Mar. 31, 2020
INVESTMENT SECURITIES [Abstract]
Amortized Cost and Estimated Fair Value of Investment Securities	The amortized cost and estimated fair value of investment securities as of March 31, 2020 and December 31, 2019 are as follows: March 31, 2020 December 31, 2019 (000's omitted) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-Sale Portfolio: U.S. Treasury and agency securities $ 2,016,500 $ 122,579 $ 0 $ 2,139,079 $ 2,030,060 $ 21,674 $ 7,975 $ 2,043,759 Obligations of state and political subdivisions 485,755 15,955 2 501,708 497,852 14,382 26 512,208 Government agency mortgage-backed securities 433,129 15,129 10 448,248 428,491 5,478 1,107 432,862 Corporate debt securities 2,512 0 4 2,508 2,527 1 0 2,528 Government agency collateralized mortgage obligations 48,681 1,658 0 50,339 52,621 482 32 53,071 Total available-for-sale portfolio $ 2,986,577 $ 155,321 $ 16 $ 3,141,882 $ 3,011,551 $ 42,017 $ 9,140 $ 3,044,428 Equity and other Securities: Equity securities, at fair value $ 251 $ 198 $ 28 $ 421 $ 251 $ 200 $ 0 $ 451 Federal Home Loan Bank common stock 6,857 0 0 6,857 7,246 0 0 7,246 Federal Reserve Bank common stock 30,922 0 0 30,922 30,922 0 0 30,922 Other equity securities, at adjusted cost 4,549 750 0 5,299 4,546 750 0 5,296 Total equity and other securities $ 42,579 $ 948 $ 28 $ 43,499 $ 42,965 $ 950 $ 0 $ 43,915
Summary of 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 is as follows: As of March 31, 2020 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: Obligations of state and political subdivisions 9 $ 1,444 $ 2 0 $ 0 $ 0 9 $ 1,444 $ 2 Government agency mortgage-backed securities 1 1,154 10 3 304 0 4 1,458 10 Corporate debt securities 1 2,508 4 0 0 0 1 2,508 4 Government agency collateralized mortgage obligations 0 0 0 2 27 0 2 27 0 Total available-for-sale investment portfolio 11 $ 5,106 $ 16 5 $ 331 $ 0 16 $ 5,437 $ 16 Equity and other Securities: Equity securities, at fair value 1 $ 73 $ 28 0 $ 0 $ 0 1 $ 73 $ 28 Total equity and other securities 1 $ 73 $ 28 0 $ 0 $ 0 1 $ 73 $ 28 As of December 31, 2019 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 12 $ 592,678 $ 7,970 5 $ 25,998 $ 5 17 $ 618,676 $ 7,975 Obligations of state and political subdivisions 21 22,716 26 0 0 0 21 22,716 26 Government agency mortgage-backed securities 50 89,237 341 52 52,975 766 102 142,212 1,107 Government agency collateralized mortgage obligations 5 5,971 14 5 4,405 18 10 10,376 32 Total available-for-sale investment portfolio 88 $ 710,602 $ 8,351 62 $ 83,378 $ 789 150 $ 793,980 $ 9,140
Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity	The amortized cost and estimated fair value of debt securities at March 31, 2020, 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 $ 662,404 $ 671,422 Due after one through five years 893,934 940,096 Due after five years through ten years 445,987 485,140 Due after ten years 502,442 546,637 Subtotal 2,504,767 2,643,295 Government agency mortgage-backed securities 433,129 448,248 Government agency collateralized mortgage obligations 48,681 50,339 Total $ 2,986,577 $ 3,141,882

LOANS (Tables)

LOANS (Tables)	3 Months Ended
	Mar. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Loans Receivable, Net	The segments of the Company’s loan portfolio are summarized as follows: (000's omitted) March 31, 2020 December 31, 2019 Business lending $ 2,789,130 $ 2,775,876 Consumer mortgage 2,424,656 2,430,902 Consumer indirect 1,087,879 1,113,062 Consumer direct 177,844 184,378 Home equity 386,583 386,325 Gross loans, including deferred origination costs 6,866,092 6,890,543 Allowance for credit losses (55,652 ) (49,911 ) Loans, net of allowance for credit losses $ 6,810,440 $ 6,840,632
Aged Analysis of Past Due Loans by Class	The following table presents the aging of the amortized cost basis of the Company’s past due loans, by class as of March 31, 2020: (000’s omitted) Past Due 30 – 89 Days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Purchased Credit Deteriorated (“PCD”) (1) Current Total Loans Business lending $ 13,157 $ 10,111 $ 4,394 $ 27,662 $ 9,781 $ 2,751,687 $ 2,789,130 Consumer mortgage 15,614 1,821 12,674 30,109 0 2,394,547 2,424,656 Consumer indirect 11,343 418 0 11,761 0 1,076,118 1,087,879 Consumer direct 1,197 62 52 1,311 0 176,533 177,844 Home equity 2,951 324 1,926 5,201 0 381,382 386,583 Total $ 44,262 $ 12,736 $ 19,046 $ 76,044 $ 9,781 $ 6,780,267 $ 6,866,092 (1) PCD loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 326-10. As a result, the noncredit discount, after the adjustment for the allowance for credit losses, is being accreted into interest income on all PCD loans. The following is an aged analysis of the Company’s past due loans by class as of December 31, 2019: 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 $ 3,936 $ 126 $ 3,840 $ 7,902 $ 1,848,683 $ 1,856,585 Consumer mortgage 10,990 2,052 10,131 23,173 1,973,543 1,996,716 Consumer indirect 12,673 125 0 12,798 1,094,510 1,107,308 Consumer direct 1,455 76 0 1,531 174,445 175,976 Home equity 1,508 328 1,444 3,280 310,727 314,007 Total $ 30,562 $ 2,707 $ 15,415 $ 48,684 $ 5,401,908 $ 5,450,592 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 $ 8,518 $ 2,173 $ 570 $ 11,261 $ 11,797 $ 896,233 $ 919,291 Consumer mortgage 890 277 2,386 3,553 0 430,633 434,186 Consumer indirect 79 31 0 110 0 5,644 5,754 Consumer direct 59 0 52 111 0 8,291 8,402 Home equity 744 238 412 1,394 0 70,924 72,318 Total $ 10,290 $ 2,719 $ 3,420 $ 16,429 $ 11,797 $ 1,411,725 $ 1,439,951 (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	All loan classes are collectively evaluated for impairment except business lending. A summary of individually evaluated impaired business loans as of March 31, 2020 and December 31, 2019 follows: (000’s omitted) March 31, 2020 December 31, 2019 Loans with allowance allocation $ 0 $ 0 Loans without allowance allocation 1,771 1,414 Carrying balance 1,771 1,414 Contractual balance 3,305 2,944 Specifically allocated allowance 0 0
Troubled Debt Restructurings on Financing Receivables	Information regarding TDRs as of March 31, 2020 and December 31, 2019 is as follows: March 31, 2020 December 31, 2019 (000’s omitted) Nonaccrual Accruing Total Nonaccrual Accruing Total # Amount # Amount # Amount # Amount # Amount # Amount Business lending 8 $ 644 3 $ 197 11 $ 841 8 $ 681 3 $ 201 11 $ 882 Consumer mortgage 60 2,646 47 2,160 107 4,806 59 2,638 47 1,892 106 4,530 Consumer indirect 0 0 89 935 89 935 0 0 84 941 84 941 Consumer direct 0 0 23 106 23 106 0 0 23 101 23 101 Home equity 13 298 11 233 24 531 13 290 11 238 24 528 Total 81 $ 3,588 173 $ 3,631 254 $ 7,219 80 $ 3,609 168 $ 3,373 248 $ 6,982 The following table presents information related to loans modified in a TDR during the three months ended March 31, 2020 and 2019. Of the loans noted in the table below, all consumer mortgage loans for the three months ended March 31, 2020 and 2019 were modified due to a Chapter 7 bankruptcy as described previously. The financial effects of these restructurings were immaterial Three Months Ended March 31, 2020 Three Months Ended March 31, 2019 (000’s omitted) Number of loans modified Outstanding Balance Number of loans modified Outstanding Balance Business lending 0 $ 0 0 $ 0 Consumer mortgage 7 617 8 665 Consumer indirect 14 127 11 98 Consumer direct 1 12 0 0 Home equity 0 0 1 4 Total 22 $ 756 20 $ 767
Allowance for Loan Losses by Class	The following presents by segment the activity in the allowance for credit losses: Three Months Ended March 31, 2020 (000’s omitted) Beginning balance, prior to the adoption of ASC 326 Impact of ASC 326 Beginning balance, after adoption of ASC 326 Charge-offs Recoveries Provision Ending balance Business lending $ 19,426 $ 288 $ 19,714 $ (176 ) $ 138 $ (187 ) $ 19,489 Consumer mortgage 10,269 (1,051 ) 9,218 (186 ) 8 3,390 12,430 Consumer indirect 13,712 (997 ) 12,715 (2,079 ) 1,163 1,895 13,694 Consumer direct 3,255 (643 ) 2,612 (533 ) 182 1,476 3,737 Home equity 2,129 808 2,937 (73 ) 6 (386 ) 2,484 Unallocated 957 43 1,000 0 0 (228 ) 772 Purchased credit deteriorated 0 3,072 3,072 0 0 (26 ) 3,046 Purchased credit impaired 163 (163 ) 0 0 0 0 0 Allowance for credit losses – loans 49,911 1,357 51,268 (3,047 ) 1,497 5,934 55,652 Liabilities for off-balance-sheet credit exposures 0 1,185 1,185 0 0 (340 ) 845 Total allowance for credit losses $ 49,911 $ 2,542 $ 52,453 $ (3,047 ) $ 1,497 $ 5,594 $ 56,497 Three Months Ended March 31, 2019 (000’s omitted) Business Lending Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Unallocated Acquired Impaired Total Beginning balance $ 18,522 $ 10,124 $ 14,366 $ 3,095 $ 2,144 $ 1,000 $ 33 $ 49,284 Charge-offs (1,216 ) (253 ) (1,823 ) (535 ) (74 ) 0 0 (3,901 ) Recoveries 134 22 962 179 5 0 0 1,302 Provision 831 424 746 317 (8 ) (10 ) 122 2,422 Ending balance $ 18,271 $ 10,317 $ 14,251 $ 3,056 $ 2,067 $ 990 $ 155 $ 49,107
Business Lending [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans by Credit Quality Indicator	The following tables show the amount of business lending loans by credit quality category at March 31, 2020 and December 31, 2019: (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year March 31, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Business lending: Risk rating Pass $ 81,301 $ 386,281 $ 333,585 $ 239,020 $ 276,171 $ 606,390 $ 593,830 $ 2,516,578 Special mention 4,128 12,290 6,887 13,213 4,516 52,457 31,223 124,714 Classified 665 1,933 17,241 9,993 12,790 59,750 45,466 147,838 Doubtful 0 0 0 0 0 0 0 0 Total business lending $ 86,094 $ 400,504 $ 357,713 $ 262,226 $ 293,477 $ 718,597 $ 670,519 $ 2,789,130 December 31, 2019 (000’s omitted) Legacy Acquired Total Pass $ 1,655,280 $ 832,693 $ 2,487,973 Special mention 98,953 45,324 144,277 Classified 102,352 29,477 131,829 Doubtful 0 0 0 Acquired impaired 0 11,797 11,797 Total $ 1,856,585 $ 919,291 $ 2,775,876
All Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans by Credit Quality Indicator	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 loans classified as current as well as those classified as - days past due. Nonperforming loans include + days past due and still accruing and nonaccrual loans. The following table details the balances in all other loan categories at March : (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year March 31, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Consumer mortgage: FICO AB Risk rating Performing $ 47,527 $ 252,841 $ 194,612 $ 190,316 $ 187,254 $ 651,314 $ 0 $ 1,523,864 Nonperforming 0 0 153 299 193 2,862 0 3,507 Total FICO AB 47,527 252,841 194,765 190,615 187,447 654,176 0 1,527,371 FICO CDE Risk rating Performing 22,589 111,126 89,451 88,630 94,419 467,433 12,649 886,297 Nonperforming 0 0 142 524 1,327 8,995 0 10,988 Total FICO CDE 22,589 111,126 89,593 89,154 95,746 476,428 12,649 897,285 Total consumer mortgage $ 70,116 $ 363,967 $ 284,358 $ 279,769 $ 283,193 $ 1,130,604 $ 12,649 $ 2,424,656 Consumer indirect: Risk rating Performing $ 74,581 $ 397,442 $ 284,899 $ 133,402 $ 102,849 $ 94,288 $ 0 $ 1,087,461 Nonperforming 0 98 78 63 99 80 0 418 Total consumer indirect $ 74,581 $ 397,540 $ 284,977 $ 133,465 $ 102,948 $ 94,368 0 $ 1,087,879 Consumer direct: Risk rating Performing $ 20,080 $ 66,306 $ 42,399 $ 21,144 $ 11,049 $ 9,121 $ 7,631 $ 177,730 Nonperforming 0 14 1 66 3 0 30 114 Total consumer direct $ 20,080 $ 66,320 $ 42,400 $ 21,210 $ 11,052 $ 9,121 $ 7,661 $ 177,844 Home equity: Risk rating Performing $ 14,521 $ 51,149 $ 28,687 $ 23,194 $ 19,318 $ 35,395 $ 212,069 $ 384,333 Nonperforming 0 0 0 73 118 461 1,598 2,250 Total home equity $ 14,521 $ 51,149 $ 28,687 $ 23,267 $ 19,436 $ 35,856 $ 213,667 $ 386,583 The following table details the balances in all other loan categories at December 31, 2019: Legacy Loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 1,984,533 $ 1,107,183 $ 175,900 $ 312,235 $ 3,579,851 Nonperforming 12,183 125 76 1,772 14,156 Total $ 1,996,716 $ 1,107,308 $ 175,976 $ 314,007 $ 3,594,007 Acquired Loans (000’s omitted) Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Total Performing $ 431,523 $ 5,723 $ 8,350 $ 71,668 $ 517,264 Nonperforming 2,663 31 52 650 3,396 Total $ 434,186 $ 5,754 $ 8,402 $ 72,318 $ 520,660

GOODWILL AND IDENTIFIABLE INT_2

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2020
GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS [Abstract]
Gross Carrying Amount and Accumulated Amortization of Identifiable Intangible Assets	The gross carrying amount and accumulated amortization for each type of identifiable intangible asset are as follows: March 31, 2020 December 31, 2019 (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 $ 66,475 $ (51,474 ) $ 15,001 $ 66,475 $ (50,057 ) $ 16,418 Other intangibles 89,266 (44,821 ) 44,445 89,266 (42,571 ) 46,695 Total amortizing intangibles $ 155,741 $ (96,295 ) $ 59,446 $ 155,741 $ (92,628 ) $ 63,113
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: (000's omitted) Apr - Dec 2020 $ 10,133 2021 11,786 2022 10,105 2023 8,457 2024 7,041 Thereafter 11,924 Total $ 59,446
Components of Goodwill	Shown below are the components of the Company’s goodwill at December 31, 2019 and March 31, 2020: (000’s omitted) December 31, 2019 Activity March 31, 2020 Goodwill $ 778,634 $ (337 ) $ 778,297 Accumulated impairment (4,824 ) 0 (4,824 ) Goodwill, net $ 773,810 $ (337 ) $ 773,473

MANDATORILY REDEEMABLE PREFER_2

MANDATORILY REDEEMABLE PREFERRED SECURITIES (Tables)	3 Months Ended
	Mar. 31, 2020
MANDATORILY REDEEMABLE PREFERRED SECURITIES [Abstract]
Terms of Preferred Securities	As of March 31, 2020, the Company sponsors business trust, Community Capital Trust IV (“CCT IV”), of which of the common stock is owned by the Company. The Company previously sponsored MBVT Statutory Trust I (“MBVT I”) and Kinderhook Capital Trust (“KCT”) until September when the Company exercised its right to redeem all of the MBVT I and KCT debentures and associated preferred securities for a total of and , respectively. The common stock of MBVT I was acquired in the Merchants Bancshares, Inc. (“Merchants”) acquisition and the common stock of KCT was acquired in the Kinderhook Bank Corp. (“Kinderhook”) acquisition. The trusts were formed for the purpose of issuing company-obligated mandatorily redeemable preferred securities to -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. As of March 31, 2020, the terms of the preferred securities of CCT IV are as follows: Issuance Par Maturity Trust Date Amount Interest Rate Date Call Price CCT IV 12/8/2006 $75.0 million 3 month LIBOR plus 1.65% (2.39%) 12/15/2036 Par

BENEFIT PLANS (Tables)

BENEFIT PLANS (Tables)	3 Months Ended
	Mar. 31, 2020
BENEFIT PLANS [Abstract]
Net Periodic Benefit Cost	The net periodic benefit cost for the three months ended March 31, 2020 and 2019 is as follows: Pension Benefits Post-retirement Benefits Three Months Ended March 31, Three Months Ended March 31, (000's omitted) 2020 2019 2020 2019 Service cost $ 1,438 $ 1,270 $ 0 $ 0 Interest cost 1,356 1,566 14 18 Expected return on plan assets (3,932 ) (3,577 ) 0 0 Amortization of unrecognized net loss 810 642 10 9 Amortization of prior service cost 60 16 (45 ) (45 ) Net periodic benefit $ (268 ) $ (83 ) $ (21 ) $ (18 )

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2020
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 three months ended March 31, 2020 and 2019: Three Months Ended March 31, (000's omitted, except per share data) 2020 2019 Net income $ 40,134 $ 41,946 Income attributable to unvested stock-based compensation awards (146 ) (109 ) Income available to common shareholders $ 39,988 $ 41,837 Weighted-average common shares outstanding – basic 52,036 51,520 Basic earnings per share $ 0.77 $ 0.81 Net income $ 40,134 $ 41,946 Income attributable to unvested stock-based compensation awards (146 ) (109 ) Income available to common shareholders $ 39,988 $ 41,837 Weighted-average common shares outstanding – basic 52,036 51,520 Assumed exercise of stock options 420 541 Weighted-average common shares outstanding – diluted 52,456 52,061 Diluted earnings per share $ 0.76 $ 0.80

COMMITMENTS, CONTINGENT LIABI_2

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS (Tables)	3 Months Ended
	Mar. 31, 2020
COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS [Abstract]
Off Balance Sheet Financial Instruments Contract Amounts	The contract amounts of commitments and contingencies are as follows: (000's omitted) March 31, 2020 December 31, 2019 Commitments to extend credit $ 1,033,133 $ 1,143,780 Standby letters of credit 39,284 37,872 Total $ 1,072,417 $ 1,181,652

FAIR VALUE (Tables)

FAIR VALUE (Tables)	3 Months Ended
	Mar. 31, 2020
FAIR VALUE [Abstract]
Fair Value Measured on a Recurring Basis	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. March 31, 2020 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,986,718 $ 152,361 $ 0 $ 2,139,079 Obligations of state and political subdivisions 0 501,708 0 501,708 Government agency mortgage-backed securities 0 448,248 0 448,248 Corporate debt securities 0 2,508 0 2,508 Government agency collateralized mortgage obligations 0 50,339 0 50,339 Total available-for-sale investment securities 1,986,718 1,155,164 0 3,141,882 Equity securities 421 0 0 421 Mortgage loans held for sale 0 3,272 0 3,272 Commitments to originate real estate loans for sale 0 0 530 530 Forward sales commitments 0 26 0 26 Interest rate swap agreements asset 0 1,825 0 1,825 Interest rate swap agreements liability 0 (1,261 ) 0 (1,261 ) Total $ 1,987,139 $ 1,159,026 $ 530 $ 3,146,695 December 31, 2019 (000's omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,878,705 $ 165,054 $ 0 $ 2,043,759 Obligations of state and political subdivisions 0 512,208 0 512,208 Government agency mortgage-backed securities 0 432,862 0 432,862 Corporate debt securities 0 2,528 0 2,528 Government agency collateralized mortgage obligations 0 53,071 0 53,071 Total available-for-sale investment securities 1,878,705 1,165,723 0 3,044,428 Equity securities 451 0 0 451 Interest rate swap agreements asset 0 851 0 851 Interest rate swap agreements liability 0 (586 ) 0 (586 ) Total $ 1,879,156 $ 1,165,988 $ 0 $ 3,045,144
Assets and Liabilities Measured on a Non-Recurring Basis	The fair value information of assets and liabilities measured on a non-recurring basis presented below is not as of the period-end, but rather as of the date the fair value adjustment was recorded closest to the date presented. March 31, 2020 December 31, 2019 (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 $ 848 $ 848 $ 0 $ 0 $ 848 $ 848 Other real estate owned 0 0 1,469 1,469 0 0 1,270 1,270 Mortgage servicing rights 0 0 52 52 0 0 56 56 Total $ 0 $ 0 $ 2,369 $ 2,369 $ 0 $ 0 $ 2,174 $ 2,174
Significant Unobservable Inputs, Fair Value Valuation Techniques	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. The significant unobservable inputs used in the determination of fair value of assets classified as Level 3 on a recurring or non-recurring basis are as follows: (000's omitted) Fair Value at March 31, 2020 Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Impaired loans $ 848 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 35.0% (27.9 %) Other real estate owned 1,469 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 85.7% (35.5 %) Commitments to originate real estate loans for sale 530 Discounted cash flow Embedded servicing value 1 % Mortgage servicing rights 52 Discounted cash flow Weighted average constant prepayment rate 43.0 % Weighted average discount rate 1.90 % Adequate compensation $7/loan (000's omitted) Fair Value at December 31, 2019 Valuation Technique Significant Unobservable Inputs Significant Unobservable Input Range (Weighted Average) Impaired loans $ 848 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 35.0% (27.9 %) Other real estate owned 1,270 Fair value of collateral Estimated cost of disposal/market adjustment 9.0% - 85.7% (37.1 %) Mortgage servicing rights 56 Discounted cash flow Weighted average constant prepayment rate 52.8 % Weighted average discount rate 3.00 % Adequate compensation $7/loan
Carrying Amounts and Estimated Fair Values of Other Financial Instruments	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 March 31, 2020 and December 31, 2019 are as follows: March 31, 2020 December 31, 2019 (000's omitted) Carrying Value Fair Value Carrying Value Fair Value Financial assets: Net loans $ 6,810,440 $ 7,063,785 $ 6,840,632 $ 7,028,663 Financial liabilities: Deposits 9,303,982 9,319,783 8,994,967 8,997,551 Overnight Federal Home Loan Bank borrowings 0 0 8,300 8,300 Securities sold under agreement to repurchase, short-term 204,991 204,991 241,708 241,708 Other Federal Home Loan Bank borrowings 3,727 3,789 3,750 3,755 Subordinated notes payable 13,775 13,775 13,795 13,795 Subordinated debt held by unconsolidated subsidiary trusts 77,320 77,320 77,320 77,320

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	3 Months Ended
	Mar. 31, 2020
DERIVATIVE INSTRUMENTS [Abstract]
Amounts Related to Cumulative Basis Adjustments for Fair Value Hedges	As of March 31, 2020 and December 31, 2019, the following amounts were recorded in the consolidated statement of condition related to cumulative basis adjustments for fair value hedges: (000’s omitted) Line Item in the Consolidated Statement of Condition in Which the Hedged Item Is Included Carrying Amount of the Hedged Assets Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets March 31, 2020 December 31, 2019 March 31, 2020 December 31, 2019 Loans $ 6,091 $ 6,390 $ (564) $ (265)
Fair Value of Derivative Instruments	Fair values of derivative instruments as of March 31, 2020 and December 31, 2019 are as follows: (000’s omitted) March 31, 2020 Derivative Assets Derivative Liabilities Consolidated Statement of Condition Location Fair Value Consolidated Statement of Condition Location Fair Value Derivatives designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets $ 564 Derivatives not designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets 1,261 Accrued interest and other liabilities $ 1,261 Commitments to originate real estate loans for sale Other assets 530 Forward sales commitments Other assets 26 Total derivatives $ 2,381 $ 1,261 (000’s omitted) December 31, 2019 Derivative Assets Derivative Liabilities Consolidated Statement of Condition Location Fair Value Consolidated Statement of Condition Location Fair Value Derivatives designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets $ 265 Derivatives not designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets 586 Accrued interest and other liabilities $ 586 Total derivatives $ 851 $ 586

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2020
SEGMENT INFORMATION [Abstract]
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 Three Months Ended March 31, 2020 Net interest income $ 89,763 $ 240 $ 51 $ 0 $ 90,054 Provision for credit losses 5,594 0 0 0 5,594 Noninterest revenues 18,680 25,925 15,536 (1,519 ) 58,622 Amortization of intangible assets 1,417 1,494 756 0 3,667 Acquisition expenses 369 0 0 0 369 Other operating expenses 64,200 15,130 11,816 (1,519 ) 89,627 Income before income taxes $ 36,863 $ 9,541 $ 3,015 $ 0 $ 49,419 Assets $ 11,633,330 $ 213,768 $ 76,525 $ (114,640 ) $ 11,808,983 Goodwill $ 669,886 $ 83,275 $ 20,312 $ 0 $ 773,473 Core deposit intangibles & Other intangibles $ 15,001 $ 36,281 $ 8,164 $ 0 $ 59,446 Three Months Ended March 31, 2019 Net interest income $ 86,715 $ 108 $ 36 $ 0 $ 86,859 Provision for credit losses 2,422 0 0 0 2,422 Noninterest revenues 17,348 24,670 14,447 (769 ) 55,696 Amortization of intangible assets 1,483 1,769 878 0 4,130 Acquisition expenses 534 0 0 0 534 Other operating expenses 59,769 14,279 10,709 (769 ) 83,988 Income before income taxes $ 39,855 $ 8,730 $ 2,896 $ 0 $ 51,481 Assets $ 10,699,384 $ 199,345 $ 71,047 $ (53,309 ) $ 10,916,467 Goodwill $ 629,916 $ 83,275 $ 20,312 $ 0 $ 733,503 Core deposit intangibles & Other intangibles $ 17,113 $ 42,777 $ 11,026 $ 0 $ 70,916

ACQUISITIONS (Details)

ACQUISITIONS (Details) $ / shares in Units, $ in Thousands	Oct. 21, 2019USD ($)CountyBranch	Sep. 18, 2019USD ($)	Jul. 12, 2019USD ($)BranchCounty	Jan. 02, 2019USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Mar. 31, 2019USD ($)	Apr. 30, 2020$ / shares
Acquisitions [Abstract]
Purchase price of acquisition			$ 95,034
Cash		$ 500	95,034		$ 0		$ 1,200
Goodwill			39,970		773,473	$ 773,810	733,503
Investment securities			39,770
Increase in deposits					309,015		$ 297,291
Customer Lists [Member]
Acquisitions [Abstract]
Intangibles		$ 500
Steuben Trust Corporation [Member]
Acquisitions [Abstract]
Purchase price of acquisition	$ 106,700
Steuben Trust Corporation [Member] | Subsequent Event [Member]
Acquisitions [Abstract]
Closing stock price (in dollars per share) | $ / shares								$ 62.49
Steuben Trust Corporation [Member] | Western New York State [Member]
Acquisitions [Abstract]
Number of counties where the bank has facilities | County	4
Number of new counties where the bank has extended footprints | County	2
Number of branch locations | Branch	14
Kinderhook Bank Corp [Member]
Acquisitions [Abstract]
Purchase price of acquisition			93,384
Cash			$ 93,384
Number of branch locations | Branch			11
Goodwill			$ 39,970
Investment securities			$ 39,770
Increase in deposits						80
Decrease in loans						(50)
Increase (decrease) in other liabilities as a result of reclassification and adjustment					(300)	40
Decrease in other assets						(40)
Increased in accrued interest and fees receivable						10
Increase (decrease) in goodwill as a result of fair value adjustment					$ (300)	$ 200
Kinderhook Bank Corp [Member] | Upstate New York [Member]
Acquisitions [Abstract]
Number of counties where the bank has facilities | County			5
Assets acquired			$ 642,800
Investment securities			39,800
Revenues			4,500
Direct expenses			$ 1,900
Wealth Resources Network, Inc [Member]
Acquisitions [Abstract]
Cash				$ 1,200
Wealth Resources Network, Inc [Member] | Customer Lists [Member]
Acquisitions [Abstract]
Intangibles				$ 1,200

ACQUISITIONS, Estimated Fair Va

ACQUISITIONS, Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands		Sep. 18, 2019	Jul. 12, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Consideration paid [Abstract]
Cash		$ 500	$ 95,034	$ 0	$ 1,200
Total net consideration paid			95,034
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents			90,381
Investment securities			39,770
Loans			479,877
Premises and equipment			13,970
Accrued interest and fees receivable			1,130
Other assets			14,109
Deposits			(568,161)
Other liabilities			(2,922)
Other Federal Home Loan Bank borrowings			(2,420)
Subordinated notes payable			(13,831)
Subordinated debt held by unconsolidated subsidiary trusts			(2,062)
Total identifiable assets, net			55,064
Goodwill			39,970	$ 773,473	$ 733,503	$ 773,810
Core Deposit Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles			3,573
Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles			1,650
Kinderhook Bank Corp [Member]
Consideration paid [Abstract]
Cash			93,384
Total net consideration paid			93,384
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents			90,381
Investment securities			39,770
Loans			479,877
Premises and equipment			13,970
Accrued interest and fees receivable			1,130
Other assets			14,109
Deposits			(568,161)
Other liabilities			(2,922)
Other Federal Home Loan Bank borrowings			(2,420)
Subordinated notes payable			(13,831)
Subordinated debt held by unconsolidated subsidiary trusts			(2,062)
Total identifiable assets, net			53,414
Goodwill			39,970
Kinderhook Bank Corp [Member] | Core Deposit Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles			3,573
Kinderhook Bank Corp [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles			0
Other [Member]
Consideration paid [Abstract]
Cash	[1]		1,650
Total net consideration paid	[1]		1,650
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents	[1]		0
Investment securities	[1]		0
Loans	[1]		0
Premises and equipment	[1]		0
Accrued interest and fees receivable	[1]		0
Other assets	[1]		0
Deposits	[1]		0
Other liabilities	[1]		0
Other Federal Home Loan Bank borrowings	[1]		0
Subordinated notes payable	[1]		0
Subordinated debt held by unconsolidated subsidiary trusts	[1]		0
Total identifiable assets, net	[1]		1,650
Goodwill	[1]		0
Other [Member] | Core Deposit Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles	[1]		0
Other [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles	[1]		$ 1,650
[1]	Includes amounts related to both acquisitions completed by CISI in 2019.

ACQUISITIONS, Summary of Loans

ACQUISITIONS, Summary of Loans Acquired (Details) - Kinderhook Bank Corp [Member] $ in Thousands	Jul. 12, 2019USD ($)
Summary of loans acquired [Abstract]
Contractually required principal and interest at acquisition	$ 649,734
Contractual cash flows not expected to be collected	(9,648)
Expected cash flows at acquisition	640,086
Interest component of expected cash flows	(160,209)
Fair value of acquired loans	479,877
Acquired Impaired Loans [Member]
Summary of loans acquired [Abstract]
Contractually required principal and interest at acquisition	13,350
Contractual cash flows not expected to be collected	(4,176)
Expected cash flows at acquisition	9,174
Interest component of expected cash flows	(551)
Fair value of acquired loans	8,623
Acquired Non Impaired Loans [Member]
Summary of loans acquired [Abstract]
Contractually required principal and interest at acquisition	636,384
Contractual cash flows not expected to be collected	(5,472)
Expected cash flows at acquisition	630,912
Interest component of expected cash flows	(159,658)
Fair value of acquired loans	$ 471,254

ACQUISITIONS, Intangible Asset,

ACQUISITIONS, Intangible Asset, Goodwill and Acquisition-related Expenses (Details) - USD ($) $ in Thousands	Jul. 12, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Fair Value of Subordinated Notes Payable [Abstract]
Subordinated notes payable		$ 13,775		$ 13,795
Summary of loans acquired [Abstract]
Merger and acquisition integration related (recoveries) expenses		$ 369	$ 534
Subordinated Notes Maturing in February 2028 [Member]
Fair Value of Subordinated Notes Payable [Abstract]
Subordinated notes payable	$ 3,000
Fixed interest rate percentage	6.00%
Maturity date	Feb. 29, 2028
Subordinated Notes Maturing in November 2025 [Member]
Fair Value of Subordinated Notes Payable [Abstract]
Subordinated notes payable	$ 10,000
Fixed interest rate percentage	6.375%
Maturity date	Nov. 30, 2025
Kinderhook Bank Corp [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life		8 years
Kinderhook Bank Corp [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life		8 years

ACCOUNTING POLICIES (Details)

ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Allowance for Credit Losses - Debt Securities [Abstract]
Accrued interest receivable on available-for-sale debt securities	$ 13,900
Loans [Abstract]
Accrued interest receivable on loans	$ 19,300
Number of days past due for loans to be placed on nonaccrual status	90 days
Contract Balances [Abstract]
Accounts receivable	$ 25,200	$ 26,800
Unbilled fee revenue	8,700	7,500
Unearned revenue	3,100	1,800
New Accounting Pronouncements [Abstract]
Retained earnings	$ 902,148	882,851
Allowance for credit losses		49,911
Consumer Installment Loans [Member]
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 [Member]
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
Consumer Mortgage [Member] | Minimum [Member]
New Accounting Pronouncements [Abstract]
Typical contract term	10 years
Consumer Mortgage [Member] | Maximum [Member]
New Accounting Pronouncements [Abstract]
Typical contract term	30 years
Home Equity [Member]
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 [Member] | Maximum [Member]
New Accounting Pronouncements [Abstract]
Typical contract term	30 years
ASU 2016-13 [Member]
New Accounting Pronouncements [Abstract]
Allowance for credit losses	$ 56,497	52,453
ASU 2016-13 [Member] | Cumulative Effect Adjustment [Member]
New Accounting Pronouncements [Abstract]
Retained earnings		500
Increase in allowance for credit losses		1,400
Adjustment to loans		3,100
Increase in other liabilities		1,200
Allowance for credit losses		$ 3,100

INVESTMENT SECURITIES, Availabl

INVESTMENT SECURITIES, Available-for-Sale Portfolio (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Available-for-Sale Portfolio [Abstract]
Amortized cost	$ 2,986,577	$ 3,011,551
Gross unrealized gains	155,321	42,017
Gross unrealized losses	16	9,140
Fair value	3,141,882	3,044,428
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	2,986,577
Fair value	3,141,882
U.S. Treasury and Agency Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	2,016,500	2,030,060
Gross unrealized gains	122,579	21,674
Gross unrealized losses	0	7,975
Fair value	2,139,079	2,043,759
Obligations of State and Political Subdivisions [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	485,755	497,852
Gross unrealized gains	15,955	14,382
Gross unrealized losses	2	26
Fair value	501,708	512,208
Government Agency Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	433,129	428,491
Gross unrealized gains	15,129	5,478
Gross unrealized losses	10	1,107
Fair value	448,248	432,862
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	2,512	2,527
Gross unrealized gains	0	1
Gross unrealized losses	4	0
Fair value	2,508	2,528
Government Agency Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	48,681	52,621
Gross unrealized gains	1,658	482
Gross unrealized losses	0	32
Fair value	$ 50,339	$ 53,071

INVESTMENT SECURITIES, Equity a

INVESTMENT SECURITIES, Equity and Other Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Equity and Other Securities [Abstract]
Amortized cost	$ 42,579	$ 42,965
Gross unrealized gains	948	950
Gross unrealized losses	28	0
Equity and other securities (cost of $42,965 and $44,678, respectively)	43,499	43,915
Equity Securities, at Fair Value [Abstract]
Amortized cost	251	251
Gross unrealized gains	198	200
Gross unrealized losses	28	0
Fair value	421	451
Federal Home Loan Bank Common Stock [Member]
Other Equity Securities, at Adjusted Cost [Abstract]
Amortized cost	6,857	7,246
Fair value	6,857	7,246
Federal Reserve Bank Common Stock [Member]
Other Equity Securities, at Adjusted Cost [Abstract]
Amortized cost	30,922	30,922
Fair value	30,922	30,922
Other Equity Securities [Member]
Other Equity Securities, at Adjusted Cost [Abstract]
Amortized cost	4,549	4,546
Gross unrealized gains	750	750
Fair value	$ 5,299	$ 5,296

INVESTMENT SECURITIES, Investme

INVESTMENT SECURITIES, Investment Securities in a Continuous Unrealized Loss Position (Details)	Mar. 31, 2020USD ($)Position	Dec. 31, 2019USD ($)Position
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	11	88
12 months or longer | Position	5	62
Total | Position	16	150
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 5,106,000	$ 710,602,000
12 months or longer	331,000	83,378,000
Total	5,437,000	793,980,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	16,000	8,351,000
12 months or longer	0	789,000
Total	$ 16,000	$ 9,140,000
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	$ 73,000
12 months or longer	0
Total	73,000
Equity and Other Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	28,000
12 months or longer	0
Total	28,000
Available-for-sale, allowance for credit losses	$ 0
U.S. Treasury and Agency Securities [Member]
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position		12
12 months or longer | Position		5
Total | Position		17
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months		$ 592,678,000
12 months or longer		25,998,000
Total		618,676,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months		7,970,000
12 months or longer		5,000
Total		$ 7,975,000
Obligations of State and Political Subdivisions [Member]
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	9	21
12 months or longer | Position	0	0
Total | Position	9	21
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 1,444,000	$ 22,716,000
12 months or longer	0	0
Total	1,444,000	22,716,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	2,000	26,000
12 months or longer	0	0
Total	$ 2,000	$ 26,000
Government Agency Mortgage-Backed Securities [Member]
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	1	50
12 months or longer | Position	3	52
Total | Position	4	102
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 1,154,000	$ 89,237,000
12 months or longer	304,000	52,975,000
Total	1,458,000	142,212,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	10,000	341,000
12 months or longer	0	766,000
Total	$ 10,000	$ 1,107,000
Corporate Debt Securities [Member]
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	1
12 months or longer | Position	0
Total | Position	1
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 2,508,000
12 months or longer	0
Total	2,508,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	4,000
12 months or longer	0
Total	$ 4,000
Corporate Debt Securities [Member] | A- or Better [Member]
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Total | Position	1
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	0	5
12 months or longer | Position	2	5
Total | Position	2	10
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 5,971,000
12 months or longer	27,000	4,405,000
Total	27,000	10,376,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	0	14,000
12 months or longer	0	18,000
Total	$ 0	$ 32,000
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	$ 73,000
12 months or longer	0
Total	73,000
Equity and Other Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	28,000
12 months or longer	0
Total	$ 28,000

INVESTMENT SECURITIES, Amortize

INVESTMENT SECURITIES, Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Due in one year or less	$ 662,404
Due after one through five years	893,934
Due after five years through ten years	445,987
Due after ten years	502,442
Subtotal	2,504,767
Amortized cost	2,986,577
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Due in one year or less	671,422
Due after one through five years	940,096
Due after five years through ten years	485,140
Due after ten years	546,637
Subtotal	2,643,295
Fair value	3,141,882
Government Agency Mortgage-Backed Securities [Member]
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	433,129
Amortized cost	433,129	$ 428,491
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Without single maturity date	448,248
Fair value	448,248	432,862
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	48,681
Amortized cost	48,681	52,621
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Without single maturity date	50,339
Fair value	$ 50,339	$ 53,071

INVESTMENT SECURITIES, Invest_2

INVESTMENT SECURITIES, Investment Securities Pledged as Collateral (Details) $ in Millions	Mar. 31, 2020USD ($)
U.S. Treasury Securities [Member] | Securities Sold under Agreements to Repurchase [Member]
Investment Securities Pledged as Collateral [Abstract]
Investment securities pledged to collateralize certain deposits and borrowings	$ 215.8

LOANS, Loan Summary (Details)

LOANS, Loan Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 6,866,092	$ 6,890,543
Allowance for credit losses	(55,652)	(49,911)	$ (49,107)	$ (49,284)
Net loans	6,810,440	6,840,632
Business Lending [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs		2,775,876
Commercial Portfolio Segment [Member] | Business Lending [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	2,789,130	2,775,876
Allowance for credit losses		(19,426)	(18,271)	(18,522)
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	2,424,656	2,430,902
Allowance for credit losses		(10,269)	(10,317)	(10,124)
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	1,087,879	1,113,062
Allowance for credit losses		(13,712)	(14,251)	(14,366)
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	177,844	184,378
Allowance for credit losses		(3,255)	(3,056)	(3,095)
Consumer Portfolio Segment [Member] | Home Equity [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 386,583	386,325
Allowance for credit losses		$ (2,129)	$ (2,067)	$ (2,144)

LOANS, Credit Quality By Past D

LOANS, Credit Quality By Past Due Status (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		$ 12,736
Nonaccrual		19,046
Total past due		76,044
Current		6,780,267
Total loans		6,866,092	$ 6,890,543
Interest income on nonaccrual loans		0
Purchased Credit Deteriorated ("PCD") [Member]
Aged analysis of the company's loans [Abstract]
Total loans	[1]	9,781
Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		44,262
Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing			2,707
Nonaccrual			15,415
Total past due			48,684
Current			5,401,908
Total loans			5,450,592
Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due			30,562
Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing			2,719
Nonaccrual			3,420
Total past due			16,429
Impaired	[2]		11,797
Current			1,411,725
Total loans			1,439,951
Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due			10,290
Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans			2,775,876
Business Lending [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			1,856,585
Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			919,291
Consumer Mortgage [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			1,996,716
Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			434,186
Consumer Indirect [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			1,107,308
Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			5,754
Consumer Direct [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			175,976
Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			8,402
Home Equity [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			314,007
Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans			72,318
Commercial Portfolio Segment [Member] | Business Lending [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		10,111
Nonaccrual		4,394
Total past due		27,662
Current		2,751,687
Total loans		2,789,130	2,775,876
Commercial Portfolio Segment [Member] | Business Lending [Member] | Purchased Credit Deteriorated ("PCD") [Member]
Aged analysis of the company's loans [Abstract]
Total loans	[1]	9,781
Commercial Portfolio Segment [Member] | Business Lending [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		13,157
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing			126
Nonaccrual			3,840
Total past due			7,902
Current			1,848,683
Total loans			1,856,585
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due			3,936
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			2,173
Nonaccrual			570
Total past due			11,261
Impaired	[2]		11,797
Current			896,233
Total loans			919,291
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			8,518
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		1,821
Nonaccrual		12,674
Total past due		30,109
Current		2,394,547
Total loans		2,424,656	2,430,902
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Purchased Credit Deteriorated ("PCD") [Member]
Aged analysis of the company's loans [Abstract]
Total loans	[1]	0
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		15,614
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing			2,052
Nonaccrual			10,131
Total past due			23,173
Current			1,973,543
Total loans			1,996,716
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due			10,990
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			277
Nonaccrual			2,386
Total past due			3,553
Impaired	[2]		0
Current			430,633
Total loans			434,186
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			890
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		418
Nonaccrual		0
Total past due		11,761
Current		1,076,118
Total loans		1,087,879	1,113,062
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Purchased Credit Deteriorated ("PCD") [Member]
Aged analysis of the company's loans [Abstract]
Total loans	[1]	0
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		11,343
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing			125
Nonaccrual			0
Total past due			12,798
Current			1,094,510
Total loans			1,107,308
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due			12,673
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			31
Nonaccrual			0
Total past due			110
Impaired	[2]		0
Current			5,644
Total loans			5,754
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			79
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		62
Nonaccrual		52
Total past due		1,311
Current		176,533
Total loans		177,844	184,378
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Purchased Credit Deteriorated ("PCD") [Member]
Aged analysis of the company's loans [Abstract]
Total loans	[1]	0
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,197
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing			76
Nonaccrual			0
Total past due			1,531
Current			174,445
Total loans			175,976
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due			1,455
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			0
Nonaccrual			52
Total past due			111
Impaired	[2]		0
Current			8,291
Total loans			8,402
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			59
Consumer Portfolio Segment [Member] | Home Equity [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		324
Nonaccrual		1,926
Total past due		5,201
Current		381,382
Total loans		386,583	386,325
Consumer Portfolio Segment [Member] | Home Equity [Member] | Purchased Credit Deteriorated ("PCD") [Member]
Aged analysis of the company's loans [Abstract]
Total loans	[1]	0
Consumer Portfolio Segment [Member] | Home Equity [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		$ 2,951
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing			328
Nonaccrual			1,444
Total past due			3,280
Current			310,727
Total loans			314,007
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due			1,508
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			238
Nonaccrual			412
Total past due			1,394
Impaired	[2]		0
Current			70,924
Total loans			72,318
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			$ 744
[1]	PCD loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 326-10. As a result, the noncredit discount, after the adjustment for the allowance for credit losses, is being accreted into interest income on all PCD loans.
[2]	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	Mar. 31, 2020	Dec. 31, 2019
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans	$ 6,866,092	$ 6,890,543
Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		5,450,592
Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,439,951
Business Lending [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	86,094
2019	400,504
2018	357,713
2017	262,226
2016	293,477
Prior	718,597
Revolving loans amortized cost basis	670,519
Total	2,789,130
Loans		2,775,876
Business Lending [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,856,585
Business Lending [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		919,291
Business Lending [Member] | Pass [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	81,301
2019	386,281
2018	333,585
2017	239,020
2016	276,171
Prior	606,390
Revolving loans amortized cost basis	593,830
Total	2,516,578
Loans		2,487,973
Business Lending [Member] | Pass [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,655,280
Business Lending [Member] | Pass [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		832,693
Business Lending [Member] | Special Mention [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	4,128
2019	12,290
2018	6,887
2017	13,213
2016	4,516
Prior	52,457
Revolving loans amortized cost basis	31,223
Total	124,714
Loans		144,277
Business Lending [Member] | Special Mention [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		98,953
Business Lending [Member] | Special Mention [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		45,324
Business Lending [Member] | Classified [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	665
2019	1,933
2018	17,241
2017	9,993
2016	12,790
Prior	59,750
Revolving loans amortized cost basis	45,466
Total	147,838
Loans		131,829
Business Lending [Member] | Classified [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		102,352
Business Lending [Member] | Classified [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		29,477
Business Lending [Member] | Doubtful [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans amortized cost basis	0
Total	0
Loans		0
Business Lending [Member] | Doubtful [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		0
Business Lending [Member] | Doubtful [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		0
Business Lending [Member] | Acquired Impaired [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		11,797
Business Lending [Member] | Acquired Impaired [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		0
Business Lending [Member] | Acquired Impaired [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		11,797
All Other Loans [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		3,594,007
All Other Loans [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		520,660
All Other Loans [Member] | Performing [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		3,579,851
All Other Loans [Member] | Performing [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		517,264
All Other Loans [Member] | Nonperforming [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		14,156
All Other Loans [Member] | Nonperforming [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		3,396
Consumer Mortgage [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	70,116
2019	363,967
2018	284,358
2017	279,769
2016	283,193
Prior	1,130,604
Revolving loans amortized cost basis	12,649
Total	2,424,656
Consumer Mortgage [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,996,716
Consumer Mortgage [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		434,186
Consumer Mortgage [Member] | Performing [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,984,533
Consumer Mortgage [Member] | Performing [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		431,523
Consumer Mortgage [Member] | Nonperforming [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		12,183
Consumer Mortgage [Member] | Nonperforming [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		2,663
Consumer Mortgage [Member] | FICO AB [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	47,527
2019	252,841
2018	194,765
2017	190,615
2016	187,447
Prior	654,176
Revolving loans amortized cost basis	0
Total	1,527,371
Consumer Mortgage [Member] | FICO AB [Member] | Performing [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	47,527
2019	252,841
2018	194,612
2017	190,316
2016	187,254
Prior	651,314
Revolving loans amortized cost basis	0
Total	1,523,864
Consumer Mortgage [Member] | FICO AB [Member] | Nonperforming [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	0
2018	153
2017	299
2016	193
Prior	2,862
Revolving loans amortized cost basis	0
Total	3,507
Consumer Mortgage [Member] | FICO CDE [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	22,589
2019	111,126
2018	89,593
2017	89,154
2016	95,746
Prior	476,428
Revolving loans amortized cost basis	12,649
Total	897,285
Consumer Mortgage [Member] | FICO CDE [Member] | Performing [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	22,589
2019	111,126
2018	89,451
2017	88,630
2016	94,419
Prior	467,433
Revolving loans amortized cost basis	12,649
Total	886,297
Consumer Mortgage [Member] | FICO CDE [Member] | Nonperforming [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	0
2018	142
2017	524
2016	1,327
Prior	8,995
Revolving loans amortized cost basis	0
Total	10,988
Consumer Indirect [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	74,581
2019	397,540
2018	284,977
2017	133,465
2016	102,948
Prior	94,368
Revolving loans amortized cost basis	0
Total	1,087,879
Consumer Indirect [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,107,308
Consumer Indirect [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		5,754
Consumer Indirect [Member] | Performing [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	74,581
2019	397,442
2018	284,899
2017	133,402
2016	102,849
Prior	94,288
Revolving loans amortized cost basis	0
Total	1,087,461
Consumer Indirect [Member] | Performing [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,107,183
Consumer Indirect [Member] | Performing [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		5,723
Consumer Indirect [Member] | Nonperforming [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	98
2018	78
2017	63
2016	99
Prior	80
Revolving loans amortized cost basis	0
Total	418
Consumer Indirect [Member] | Nonperforming [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		125
Consumer Indirect [Member] | Nonperforming [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		31
Consumer Direct [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	20,080
2019	66,320
2018	42,400
2017	21,210
2016	11,052
Prior	9,121
Revolving loans amortized cost basis	7,661
Total	177,844
Consumer Direct [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		175,976
Consumer Direct [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		8,402
Consumer Direct [Member] | Performing [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	20,080
2019	66,306
2018	42,399
2017	21,144
2016	11,049
Prior	9,121
Revolving loans amortized cost basis	7,631
Total	177,730
Consumer Direct [Member] | Performing [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		175,900
Consumer Direct [Member] | Performing [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		8,350
Consumer Direct [Member] | Nonperforming [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	14
2018	1
2017	66
2016	3
Prior	0
Revolving loans amortized cost basis	30
Total	114
Consumer Direct [Member] | Nonperforming [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		76
Consumer Direct [Member] | Nonperforming [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		52
Home Equity [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	14,521
2019	51,149
2018	28,687
2017	23,267
2016	19,436
Prior	35,856
Revolving loans amortized cost basis	213,667
Total	386,583
Home Equity [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		314,007
Home Equity [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		72,318
Home Equity [Member] | Performing [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	14,521
2019	51,149
2018	28,687
2017	23,194
2016	19,318
Prior	35,395
Revolving loans amortized cost basis	212,069
Total	384,333
Home Equity [Member] | Performing [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		312,235
Home Equity [Member] | Performing [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		71,668
Home Equity [Member] | Nonperforming [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	0
2018	0
2017	73
2016	118
Prior	461
Revolving loans amortized cost basis	1,598
Total	$ 2,250
Home Equity [Member] | Nonperforming [Member] | Legacy Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		1,772
Home Equity [Member] | Nonperforming [Member] | Acquired Loans [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans		$ 650

LOANS, Summary of Impaired Loan

LOANS, Summary of Impaired Loans, Excluding Purchased Impaired (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Impaired loans [Abstract]
Loans with allowance allocation	$ 0		$ 0
Loans without allowance allocation	1,771		1,414
Carrying balance	1,771		1,414
Contractual balance	3,305		2,944
Specifically allocated allowance	0		$ 0
Average carrying balance of individually evaluated impaired loans	2,200	$ 6,200
Interest income on individually evaluated impaired loans	$ 0	$ 0

LOANS, Troubled Debt Restructur

LOANS, Troubled Debt Restructurings (TDRs) (Details)	3 Months Ended
	Mar. 31, 2020USD ($)Loan	Mar. 31, 2019USD ($)Loan	Dec. 31, 2019USD ($)Loan
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	254		248
TDRs, amount	$ 7,219,000		$ 6,982,000
Loans modified in TDR during the year, number | Loan	22	20
Loans modified in TDR during the year, amount	$ 756,000	$ 767,000
Maximum [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
Threshold balance of TDR loans collectively included in general loan loss allocation and qualitative review	$ 500,000
Deferral period under customer payment deferral program	3 months
Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	81		80
TDRs, amount	$ 3,588,000		$ 3,609,000
Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	173		168
TDRs, amount	$ 3,631,000		$ 3,373,000
Commercial Portfolio Segment [Member] | Minimum [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
Threshold balance of loans individually evaluated for impairment	$ 500,000
Commercial Portfolio Segment [Member] | Business Lending [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	11		11
TDRs, amount	$ 841,000		$ 882,000
Loans modified in TDR during the year, number | Loan	0	0
Loans modified in TDR during the year, amount	$ 0	$ 0
Commercial Portfolio Segment [Member] | Business Lending [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	8		8
TDRs, amount	$ 644,000		$ 681,000
Commercial Portfolio Segment [Member] | Business Lending [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	3		3
TDRs, amount	$ 197,000		$ 201,000
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	107		106
TDRs, amount	$ 4,806,000		$ 4,530,000
Loans modified in TDR during the year, number | Loan	7	8
Loans modified in TDR during the year, amount	$ 617,000	$ 665,000
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	60		59
TDRs, amount	$ 2,646,000		$ 2,638,000
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	47		47
TDRs, amount	$ 2,160,000		$ 1,892,000
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	89		84
TDRs, amount	$ 935,000		$ 941,000
Loans modified in TDR during the year, number | Loan	14	11
Loans modified in TDR during the year, amount	$ 127,000	$ 98,000
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	89		84
TDRs, amount	$ 935,000		$ 941,000
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	23		23
TDRs, amount	$ 106,000		$ 101,000
Loans modified in TDR during the year, number | Loan	1	0
Loans modified in TDR during the year, amount	$ 12,000	$ 0
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	23		23
TDRs, amount	$ 106,000		$ 101,000
Consumer Portfolio Segment [Member] | Home Equity [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	24		24
TDRs, amount	$ 531,000		$ 528,000
Loans modified in TDR during the year, number | Loan	0	1
Loans modified in TDR during the year, amount	$ 0	$ 4,000
Consumer Portfolio Segment [Member] | Home Equity [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	13		13
TDRs, amount	$ 298,000		$ 290,000
Consumer Portfolio Segment [Member] | Home Equity [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	11		11
TDRs, amount	$ 233,000		$ 238,000

LOANS, Allowance for Credit Los

LOANS, Allowance for Credit Losses (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Mar. 31, 2021USD ($)
Allowance for credit losses - loans [Roll Forward]
Beginning balance	$ 49,911	$ 49,284	$ 55,652
Charge-offs		(3,901)
Recoveries		1,302
Provision		2,422
Ending balance	55,652	49,107
Liabilities for off-balance-sheet credit exposures [Roll Forward]
Beginning balance	0
Total allowance for credit losses [Roll Forward]
Beginning balance	49,911
Provision	$ 5,594	2,422
Allowance for Credit Losses [Abstract]
Allowance for credit losses to total loans ratio	0.0081
Increase in allowance for credit losses to total loans ratio over the same quarter in prior year	300.00%
Increase in allowance for credit losses to total loans ratio over the prior year end	900.00%
Forecast [Member] | Minimum [Member] | COVID-19 [Member]
Allowance for Credit Losses [Abstract]
Percentage of peak unemployment			8.00%
Forecast [Member] | Maximum [Member] | COVID-19 [Member]
Allowance for Credit Losses [Abstract]
Percentage of peak unemployment			13.00%
ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	$ 51,268		$ 55,652
Charge-offs	(3,047)
Recoveries	1,497
Provision	5,934
Ending balance	55,652
Liabilities for off-balance-sheet credit exposures [Roll Forward]
Beginning balance	1,185		845
Charge-offs	0
Recoveries	0
Provision	(340)
Ending balance	845
Total allowance for credit losses [Roll Forward]
Beginning balance	52,453		56,497
Charge-offs	(3,047)
Recoveries	1,497
Provision	5,594
Ending balance	56,497
ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	1,357
Liabilities for off-balance-sheet credit exposures [Roll Forward]
Beginning balance	1,185
Total allowance for credit losses [Roll Forward]
Beginning balance	2,542
Purchased Credit Impaired [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	163	33
Charge-offs		0
Recoveries		0
Provision		122
Ending balance		155
Purchased Credit Impaired [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	0		0
Charge-offs	0
Recoveries	0
Provision	0
Ending balance	0
Purchased Credit Impaired [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	(163)
Purchased Credit Deteriorated [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	0
Purchased Credit Deteriorated [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	3,072		3,046
Charge-offs	0
Recoveries	0
Provision	(26)
Ending balance	3,046
Purchased Credit Deteriorated [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	3,072
Commercial Portfolio Segment [Member] | Business Lending [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	19,426	18,522
Charge-offs		(1,216)
Recoveries		134
Provision		831
Ending balance		18,271
Commercial Portfolio Segment [Member] | Business Lending [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	19,714		19,489
Charge-offs	(176)
Recoveries	138
Provision	(187)
Ending balance	19,489
Commercial Portfolio Segment [Member] | Business Lending [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	288
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	10,269	10,124
Charge-offs		(253)
Recoveries		22
Provision		424
Ending balance		10,317
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	9,218		12,430
Charge-offs	(186)
Recoveries	8
Provision	3,390
Ending balance	12,430
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	(1,051)
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	13,712	14,366
Charge-offs		(1,823)
Recoveries		962
Provision		746
Ending balance		14,251
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	12,715		13,694
Charge-offs	(2,079)
Recoveries	1,163
Provision	1,895
Ending balance	13,694
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	(997)
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	3,255	3,095
Charge-offs		(535)
Recoveries		179
Provision		317
Ending balance		3,056
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	2,612		3,737
Charge-offs	(533)
Recoveries	182
Provision	1,476
Ending balance	3,737
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	(643)
Consumer Portfolio Segment [Member] | Home Equity [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	2,129	2,144
Charge-offs		(74)
Recoveries		5
Provision		(8)
Ending balance		2,067
Consumer Portfolio Segment [Member] | Home Equity [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	2,937		2,484
Charge-offs	(73)
Recoveries	6
Provision	(386)
Ending balance	2,484
Consumer Portfolio Segment [Member] | Home Equity [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	808
Unallocated Financing Receivables [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	957	1,000
Charge-offs		0
Recoveries		0
Provision		(10)
Ending balance		$ 990
Unallocated Financing Receivables [Member] | ASU 2016-13 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	1,000		$ 772
Charge-offs	0
Recoveries	0
Provision	(228)
Ending balance	772
Unallocated Financing Receivables [Member] | ASU 2016-13 [Member] | Impact of ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance	$ 43

GOODWILL AND IDENTIFIABLE INT_3

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Identifiable Intangible Assets [Abstract]
Gross carrying amount	$ 155,741	$ 155,741
Accumulated amortization	(96,295)	(92,628)
Net carrying amount	59,446	63,113
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Apr - Dec 2020	10,133
2021	11,786
2022	10,105
2023	8,457
2024	7,041
Thereafter	11,924
Net carrying amount	59,446	63,113
Components of goodwill [Abstract]
Goodwill, beginning of period	778,634
Goodwill, activity	(337)
Goodwill, end of period	778,297
Accumulated impairment, beginning of period	(4,824)
Accumulated impairment, activity	0
Accumulated impairment, end of period	(4,824)
Goodwill, net, beginning of period	773,810
Goodwill, net, activity	(337)
Goodwill, net, end of period	773,473
Core Deposit Intangibles [Member]
Identifiable Intangible Assets [Abstract]
Gross carrying amount	66,475	66,475
Accumulated amortization	(51,474)	(50,057)
Net carrying amount	15,001	16,418
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Net carrying amount	15,001	16,418
Other Intangibles [Member]
Identifiable Intangible Assets [Abstract]
Gross carrying amount	89,266	89,266
Accumulated amortization	(44,821)	(42,571)
Net carrying amount	44,445	46,695
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Net carrying amount	$ 44,445	$ 46,695

MANDATORILY REDEEMABLE PREFER_3

MANDATORILY REDEEMABLE PREFERRED SECURITIES (Details) $ in Millions	Sep. 16, 2019USD ($)	Mar. 31, 2020USD ($)Trust
Mandatorily Redeemable Preferred Securities [Abstract]
Number of unconsolidated subsidiary business trusts owned | Trust		1
Business Trust [Member]
Mandatorily Redeemable Preferred Securities [Abstract]
Percent ownership of unconsolidated subsidiary trusts		100.00%
MBVT Statutory Trust I [Member]
Mandatorily Redeemable Preferred Securities [Abstract]
Redemption of debentures and associated preferred securities	$ 20.6
Kinderhook Capital Trust [Member]
Mandatorily Redeemable Preferred Securities [Abstract]
Redemption of debentures and associated preferred securities	$ 2.1
Preferred Debt [Member] | Community Capital Trust IV [Member]
Terms of preferred securities for each trust [Abstract]
Issuance date		Dec. 8, 2006
Par amount		$ 75
Effective interest rate		2.39%
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%

BENEFIT PLANS (Details)

BENEFIT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Pension Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	$ 1,438	$ 1,270
Interest cost	1,356	1,566
Expected return on plan assets	(3,932)	(3,577)
Amortization of unrecognized net loss	810	642
Amortization of prior service cost	60	16
Net periodic benefit	(268)	(83)
Pension Benefits [Member] | Nonqualified Plan [Member] | Unfunded Plan [Member]
Pension Plans [Abstract]
Contribution made to defined benefit pension plan by employer	0	7,300
Post-retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	0	0
Interest cost	14	18
Expected return on plan assets	0	0
Amortization of unrecognized net loss	10	9
Amortization of prior service cost	(45)	(45)
Net periodic benefit	$ (21)	$ (18)

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
EARNINGS PER SHARE [Abstract]
Weighted-average anti-dilutive stock options outstanding (in shares)	200,000	500,000
Basic earnings per share [Abstract]
Net income	$ 40,134	$ 41,946
Income attributable to unvested stock-based compensation awards	(146)	(109)
Income available to common shareholders	$ 39,988	$ 41,837
Weighted-average common shares outstanding - basic (in shares)	52,036,000	51,520,000
Basic earnings per share (in dollars per share)	$ 0.77	$ 0.81
Diluted earnings per share [Abstract]
Net income	$ 40,134	$ 41,946
Income attributable to unvested stock-based compensation awards	(146)	(109)
Income available to common shareholders	$ 39,988	$ 41,837
Weighted-average common shares outstanding - basic (in shares)	52,036,000	51,520,000
Assumed exercise of stock options (in shares)	420,000	541,000
Weighted-average common shares outstanding - diluted (in shares)	52,456,000	52,061,000
Diluted earnings per share (in dollars per share)	$ 0.76	$ 0.80
Stock Repurchase Program [Abstract]
Number of common shares authorized to be repurchased (in shares)			2,600,000	2,500,000
Number of common shares repurchased (in shares)	0	0

COMMITMENTS, CONTINGENT LIABI_3

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Commitments, Contingent Liabilities and Restrictions [Abstract]
Contract amount of commitments and contingencies	$ 1,072,417	$ 1,181,652
Minimum [Member]
Commitments, Contingent Liabilities and Restrictions [Abstract]
Range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability	0
Maximum [Member]
Commitments, Contingent Liabilities and Restrictions [Abstract]
Range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability	1,000
Commitments to Extend Credit [Member]
Commitments, Contingent Liabilities and Restrictions [Abstract]
Contract amount of commitments and contingencies	1,033,133	1,143,780
Standby Letters of Credit [Member]
Commitments, Contingent Liabilities and Restrictions [Abstract]
Contract amount of commitments and contingencies	$ 39,284	$ 37,872

FAIR VALUE, Financial Assets an

FAIR VALUE, Financial Assets and Liabilities Accounted for at Fair Value On a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	$ 3,141,882
Equity securities	421	$ 451
Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	530
U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,139,079	2,043,759
Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	501,708	512,208
Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	448,248	432,862
Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,508	2,528
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	50,339	53,071
Recurring [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	3,141,882	3,044,428
Equity securities	421	451
Mortgage loans held for sale	3,272
Total	3,146,695	3,045,144
Recurring [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	530
Recurring [Member] | Forward Sales Commitments [Member]
Available-for-sale investment securities [Abstract]
Derivative liability	26
Recurring [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	1,825	851
Derivative liability	(1,261)	(586)
Recurring [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,139,079	2,043,759
Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	501,708	512,208
Recurring [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	448,248	432,862
Recurring [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,508	2,528
Recurring [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	50,339	53,071
Recurring [Member] | Level 1 [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	1,986,718	1,878,705
Equity securities	421	451
Mortgage loans held for sale	0
Total	1,987,139	1,879,156
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 liability	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	1,986,718	1,878,705
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]
Available-for-sale investment securities	1,155,164	1,165,723
Equity securities	0	0
Mortgage loans held for sale	3,272
Total	1,159,026	1,165,988
Mortgage loans held for sale, at principal value	3,000	0
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 liability	26
Recurring [Member] | Level 2 [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	1,825	851
Derivative liability	(1,261)	(586)
Recurring [Member] | Level 2 [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	152,361	165,054
Recurring [Member] | Level 2 [Member] | Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	501,708	512,208
Recurring [Member] | Level 2 [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	448,248	432,862
Recurring [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,508	2,528
Recurring [Member] | Level 2 [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	50,339	53,071
Recurring [Member] | Level 3 [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	0	0
Equity securities	0	0
Mortgage loans held for sale	0
Total	530	0
Recurring [Member] | Level 3 [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	530
Recurring [Member] | Level 3 [Member] | Forward Sales Commitments [Member]
Available-for-sale investment securities [Abstract]
Derivative liability	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	Mar. 31, 2020	Dec. 31, 2019
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	$ 848	$ 848
Other real estate owned	1,469	1,270
Mortgage servicing rights	52	56
Valuation allowance	0	0
Mortgage Servicing Rights [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Valuation allowance	200	300
Non-recurring [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	848	848
Other real estate owned	1,469	1,270
Mortgage servicing rights	52	56
Total	2,369	2,174
Non-recurring [Member] | Level 1 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	0	0
Other real estate owned	0	0
Mortgage servicing rights	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
Mortgage servicing rights	0	0
Total	0	0
Non-recurring [Member] | Level 3 [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	848	848
Other real estate owned	1,469	1,270
Mortgage servicing rights	52	56
Total	$ 2,369	$ 2,174

FAIR VALUE, Significant Unobser

FAIR VALUE, Significant Unobservable Inputs (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Impaired loans	$ 848	$ 848
Other real estate owned	$ 1,469	$ 1,270
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
Mortgage servicing rights	$ 52	$ 56
us-gaap_ValuationTechniqueDiscountedCashFlowMember | Weighted Average Constant Prepayment Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	0.430	0.528
us-gaap_ValuationTechniqueDiscountedCashFlowMember | Weighted Average Discount Rate [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	0.0190	0.0300
us-gaap_ValuationTechniqueDiscountedCashFlowMember | Adequate Compensation [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Mortgage servicing rights, measurement input	7	7
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	0.090
Other real estate owned, measurement input	0.090	0.090
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	0.350	0.350
Other real estate owned, measurement input	0.857	0.857
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	0.279	0.279
Other real estate owned, measurement input	0.355	0.371
Commitments to Originate Real Estate Loans for Sale [Member]
Significant Unobservable Inputs used in determination of Fair Value of Assets Classified as Level 3 [Abstract]
Commitments to originate real estate loans for sale	$ 530
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 [Extensible List]	cbu:MeasurementInputEmbeddedServicingValueMember
Commitments to originate real estate loans for sale, measurement input	0.01

FAIR VALUE, Carrying Amounts an

FAIR VALUE, Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Carrying Value [Member]
Financial assets [Abstract]
Net loans	$ 6,810,440	$ 6,840,632
Financial liabilities [Abstract]
Deposits	9,303,982	8,994,967
Overnight Federal Home Loan Bank borrowings	0	8,300
Securities sold under agreement to repurchase, short-term	204,991	241,708
Other Federal Home Loan Bank borrowings	3,727	3,750
Subordinated notes payable	13,775	13,795
Subordinated debt held by unconsolidated subsidiary trusts	77,320	77,320
Fair Value [Member]
Financial assets [Abstract]
Net loans	7,063,785	7,028,663
Financial liabilities [Abstract]
Deposits	9,319,783	8,997,551
Overnight Federal Home Loan Bank borrowings	0	8,300
Securities sold under agreement to repurchase, short-term	204,991	241,708
Other Federal Home Loan Bank borrowings	3,789	3,755
Subordinated notes payable	13,775	13,795
Subordinated debt held by unconsolidated subsidiary trusts	$ 77,320	$ 77,320

DERIVATIVE INSTRUMENTS (Details

DERIVATIVE INSTRUMENTS (Details) - Interest Rate Swaps [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Derivative Instruments [Abstract]
Derivative, notional amount	$ 16	$ 16.4
Derivative weighted average receive rate	2.88%	3.72%
Derivative weighted average pay rate	4.39%	4.39%
Weighted average maturity period	5 years 10 months 24 days	6 years 1 month 6 days
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative Instruments [Abstract]
Derivative, notional amount	$ 6.2	$ 6.2
Derivative weighted average receive rate	1.92%	2.47%
Derivative weighted average pay rate	3.11%	3.11%
Weighted average maturity period	13 years 3 months 18 days	13 years 6 months

DERIVATIVE INSTRUMENTS, Cumulat

DERIVATIVE INSTRUMENTS, Cumulative Basis Adjustments for Fair Value Hedges (Details) - Loans [Member] - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Cumulative Basis Adjustments for Fair Value Hedges [Abstract]
Carrying amount of the hedged assets	$ 6,091	$ 6,390
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets	$ (564)	$ (265)

DERIVATIVE INSTRUMENTS, Fair Va

DERIVATIVE INSTRUMENTS, Fair Values of Derivative Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Values of Derivative Instruments [Abstract]
Derivative assets	$ 2,381	$ 851
Derivative liabilities	1,261	586
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative assets	564	265
Interest Rate Swaps [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative assets	1,261	586
Interest Rate Swaps [Member] | Not Designated as Hedging Instrument [Member] | Accrued Interest and Other Liabilities [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative liabilities	1,261	$ 586
Commitments to Originate Real Estate Loans for Sale [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative assets	530
Forward Sales Commitments [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative assets	$ 26

SEGMENT INFORMATION (Details)

SEGMENT INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Jul. 12, 2019
Information about reportable segments [Abstract]
Net interest income	$ 90,054	$ 86,859
Provision for credit losses	5,594	2,422
Noninterest revenues	58,622	55,696
Amortization of intangible assets	3,667	4,130
Acquisition expenses	369	534
Other operating expenses	89,627	83,988
Income before income taxes	49,419	51,481
Assets	11,808,983	10,916,467	$ 11,410,295
Goodwill	773,473	733,503	$ 773,810	$ 39,970
Core deposit intangibles & Other intangibles	59,446	70,916
Eliminations [Member]
Information about reportable segments [Abstract]
Net interest income	0	0
Provision for credit losses	0	0
Noninterest revenues	(1,519)	(769)
Amortization of intangible assets	0	0
Acquisition expenses	0	0
Other operating expenses	(1,519)	(769)
Income before income taxes	0	0
Assets	(114,640)	(53,309)
Goodwill	0	0
Core deposit intangibles & Other intangibles	0	0
Banking [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	89,763	86,715
Provision for credit losses	5,594	2,422
Noninterest revenues	18,680	17,348
Amortization of intangible assets	1,417	1,483
Acquisition expenses	369	534
Other operating expenses	64,200	59,769
Income before income taxes	36,863	39,855
Assets	11,633,330	10,699,384
Goodwill	669,886	629,916
Core deposit intangibles & Other intangibles	15,001	17,113
Employee Benefit Services [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	240	108
Provision for credit losses	0	0
Noninterest revenues	25,925	24,670
Amortization of intangible assets	1,494	1,769
Acquisition expenses	0	0
Other operating expenses	15,130	14,279
Income before income taxes	9,541	8,730
Assets	213,768	199,345
Goodwill	83,275	83,275
Core deposit intangibles & Other intangibles	36,281	42,777
All Other [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	51	36
Provision for credit losses	0	0
Noninterest revenues	15,536	14,447
Amortization of intangible assets	756	878
Acquisition expenses	0	0
Other operating expenses	11,816	10,709
Income before income taxes	3,015	2,896
Assets	76,525	71,047
Goodwill	20,312	20,312
Core deposit intangibles & Other intangibles	$ 8,164	$ 11,026