Community Bank System (CBU) 10-Q 10 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 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		53,529,607
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
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	Jun. 30, 2020	Dec. 31, 2019
Assets:
Cash and cash equivalents	$ 1,319,880	$ 205,030
Available-for-sale investment securities (cost of $3,129,978 and $3,011,551, respectively)	3,293,116	3,044,428
Equity and other securities (cost of $43,411 and $42,965, respectively)	44,343	43,915
Loans held for sale, at fair value	5,517	0
Loans	7,528,039	6,890,543
Allowance for credit losses	(64,437)	(49,911)
Net loans	7,463,602	6,840,632
Goodwill, net	792,715	773,810
Core deposit intangibles, net	16,565	16,418
Other intangibles, net	43,481	46,695
Intangible assets, net	852,761	836,923
Premises and equipment, net	167,301	164,638
Accrued interest and fees receivable	38,553	31,647
Other assets	259,144	243,082
Total assets	13,444,217	11,410,295
Liabilities:
Noninterest-bearing deposits	3,273,921	2,465,902
Interest-bearing deposits	7,572,752	6,529,065
Total deposits	10,846,673	8,994,967
Overnight Federal Home Loan Bank borrowings	0	8,300
Securities sold under agreement to repurchase, short-term	168,491	241,708
Other Federal Home Loan Bank borrowings	7,704	3,750
Subordinated notes payable	13,755	13,795
Subordinated debt held by unconsolidated subsidiary trusts	79,382	77,320
Accrued interest and other liabilities	246,897	215,221
Total liabilities	11,362,902	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; 53,673,335 and 51,974,726 shares issued, respectively	53,672	51,975
Additional paid-in capital	1,019,291	927,337
Retained earnings	915,392	882,851
Accumulated other comprehensive gain (loss)	90,031	(10,226)
Treasury stock, at cost (159,119 shares, including 157,897 shares held by deferred compensation arrangements at June 30, 2020 and 180,803 shares including 179,548 shares held by deferred compensation arrangements at December 31, 2019, respectively)	(6,066)	(6,823)
Deferred compensation arrangements (157,897 and 179,548 shares, respectively)	8,995	10,120
Total shareholders' equity	2,081,315	1,855,234
Total liabilities and shareholders' equity	$ 13,444,217	$ 11,410,295

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF CONDITION (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets:
Available-for-sale investment securities, cost	$ 3,129,978	$ 3,011,551
Equity and other securities, cost	$ 43,411	$ 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)	53,673,335	51,974,726
Treasury stock, shares at cost (in shares)	159,119	180,803
Shares held by deferred compensation arrangements (in shares)	157,897	179,548

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest income:
Interest and fees on loans	$ 78,720	$ 74,067	$ 157,285	$ 147,770
Interest and dividends on taxable investments	15,423	17,427	30,752	33,514
Interest and dividends on nontaxable investments	3,049	2,858	6,150	5,749
Total interest income	97,192	94,352	194,187	187,033
Interest expense:
Interest on deposits	4,173	4,560	9,718	8,667
Interest on borrowings	430	429	988	1,050
Interest on subordinated notes payable	184	0	369	0
Interest on subordinated debt held by unconsolidated subsidiary trusts	454	1,063	1,107	2,157
Total interest expense	5,241	6,052	12,182	11,874
Net interest income	91,951	88,300	182,005	175,159
Provision for credit losses	9,774	1,400	15,368	3,822
Net interest income after provision for credit losses	82,177	86,900	166,637	171,337
Noninterest revenues:
Deposit service fees	12,179	15,996	28,462	31,860
Mortgage banking	1,375	213	2,291	414
Other banking services	755	934	1,650	2,269
Employee benefit services	24,068	23,787	49,434	47,841
Insurance services	8,183	8,329	16,241	16,191
Wealth management services	6,366	6,578	13,500	12,927
Gain on sale of investment securities, net	0	4,882	0	4,882
Unrealized gain (loss) on equity securities	12	(13)	(18)	18
Total noninterest revenues	52,938	60,706	111,560	116,402
Noninterest expenses:
Salaries and employee benefits	54,721	54,008	112,972	107,387
Occupancy and equipment	9,754	9,619	20,493	19,907
Data processing and communications	10,833	10,401	21,246	19,800
Amortization of intangible assets	3,524	3,904	7,191	8,034
Legal and professional fees	3,061	2,684	6,212	5,404
Business development and marketing	1,504	3,140	4,017	5,928
Acquisition expenses	3,372	1,194	3,741	1,728
Other expenses	4,134	6,226	8,694	11,640
Total noninterest expenses	90,903	91,176	184,566	179,828
Income before income taxes	44,212	56,430	93,631	107,911
Income taxes	8,964	11,415	18,249	20,950
Net income	$ 35,248	$ 45,015	$ 75,382	$ 86,961
Basic earnings per share (in dollars per share)	$ 0.67	$ 0.87	$ 1.44	$ 1.68
Diluted earnings per share (in dollars per share)	$ 0.66	$ 0.86	$ 1.43	$ 1.66

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Pension and other post retirement obligations:
Amortization of actuarial losses included in net periodic pension cost, gross	$ 820	$ 652	$ 1,640	$ 1,303
Tax effect	(197)	(160)	(394)	(319)
Amortization of actuarial losses included in net periodic pension cost, net	623	492	1,246	984
Amortization of prior service cost included in net periodic pension cost, gross	16	(29)	31	(58)
Tax effect	(4)	8	(7)	15
Amortization of prior service cost included in net periodic pension cost, net	12	(21)	24	(43)
Other comprehensive income related to pension and other post-retirement obligations, net of taxes	635	471	1,270	941
Unrealized gains on available-for-sale securities:
Net unrealized holding gains arising during period, gross	7,832	33,547	130,260	57,452
Tax effect	(1,880)	(8,189)	(31,273)	(14,021)
Net unrealized holding gains arising during period, net	5,952	25,358	98,987	43,431
Reclassification adjustment for net gains included in net income, gross	0	(4,882)	0	(4,882)
Tax effect	0	1,194	0	1,194
Reclassification adjustment for net gains included in net income, net	0	(3,688)	0	(3,688)
Other comprehensive income related to unrealized gains on available-for-sale securities, net of taxes	5,952	21,670	98,987	39,743
Other comprehensive income, net of tax	6,587	22,141	100,257	40,684
Net income	35,248	45,015	75,382	86,961
Comprehensive income	41,835	$ 67,156	175,639	$ 127,645
Accumulated Other Comprehensive Income By Component:
Unrealized (loss) for pension and other post-retirement obligations	(44,504)		(44,504)		$ (46,175)
Tax effect	10,892		10,892		11,293
Net unrealized (loss) for pension and other post-retirement obligations	(33,612)		(33,612)		(34,882)
Unrealized gain on available-for-sale securities	163,137		163,137		32,877
Tax effect	(39,494)		(39,494)		(8,221)
Net unrealized gain on available-for-sale securities	123,643		123,643		24,656
Accumulated other comprehensive income (loss)	$ 90,031		$ 90,031		$ (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]	Accumulated Other Comprehensive (Loss) Income [Member]	Treasury Stock [Member]	Deferred Compensation Arrangements [Member]	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [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				86,961				86,961
Other comprehensive income, net of tax					40,684			40,684
Cash dividends declared:
Common				(39,236)				(39,236)
Common stock activity under employee stock ownership plan		229	992					1,221
Common stock activity under employee stock ownership plan (in shares)	228,585
Stock-based compensation			2,757					2,757
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			1,294			1,901	145	3,340
Treasury stock issued to benefit plans, net (in shares)	51,768
Balance at Jun. 30, 2019		51,806	917,855	843,288	(4,621)	(8,797)	9,979	1,809,510
Balance (in shares) at Jun. 30, 2019	51,570,608
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				45,015				45,015
Other comprehensive income, net of tax					22,141			22,141
Cash dividends declared:
Common				(19,660)				(19,660)
Common stock activity under employee stock ownership plan		78	1,987					2,065
Common stock activity under employee stock ownership plan (in shares)	77,666
Stock-based compensation			1,366					1,366
Treasury stock issued to benefit plans, net			585			804	66	1,455
Treasury stock issued to benefit plans, net (in shares)	21,571
Balance at Jun. 30, 2019		51,806	917,855	843,288	(4,621)	(8,797)	9,979	1,809,510
Balance (in shares) at Jun. 30, 2019	51,570,608
Balance at Dec. 31, 2019		51,975	927,337	882,851	(10,226)	(6,823)	10,120	1,855,234
Balance (ASU 2016-13 [Member]) at Dec. 31, 2019									$ 530	$ 530
Balance (in shares) at Dec. 31, 2019	51,793,923
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				75,382				75,382
Other comprehensive income, net of tax					100,257			100,257
Cash dividends declared:
Common				(43,371)				(43,371)
Common stock activity under employee stock ownership plan		334	12,689					13,023
Common stock activity under employee stock ownership plan (in shares)	333,556
Stock-based compensation			3,233					3,233
Stock issued for acquisition		1,363	75,579					76,942
Stock issued for acquisition (in shares)	1,363,259
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			38			(92)	139	85
Treasury stock issued to benefit plans, net (in shares)	981
Balance at Jun. 30, 2020		53,672	1,019,291	915,392	90,031	(6,066)	8,995	2,081,315
Balance (in shares) at Jun. 30, 2020	53,514,216
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				35,248				35,248
Other comprehensive income, net of tax					6,587			6,587
Cash dividends declared:
Common				(22,004)				(22,004)
Common stock activity under employee stock ownership plan		119	6,505					6,624
Common stock activity under employee stock ownership plan (in shares)	118,968
Stock-based compensation			1,281					1,281
Stock issued for acquisition		1,363	75,579					76,942
Stock issued for acquisition (in shares)	1,363,259
Treasury stock issued to benefit plans, net			2			(61)	65	6
Treasury stock issued to benefit plans, net (in shares)	897
Balance at Jun. 30, 2020		$ 53,672	$ 1,019,291	$ 915,392	$ 90,031	$ (6,066)	$ 8,995	$ 2,081,315
Balance (in shares) at Jun. 30, 2020	53,514,216

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cash dividends declared:
Dividends declared per common share (in dollars per share)	$ 0.41	$ 0.38	$ 0.82	$ 0.76

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net income	$ 75,382	$ 86,961
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,995	7,680
Amortization of intangible assets	7,191	8,034
Net accretion on securities, loans and borrowings	(5,902)	(3,462)
Stock-based compensation	3,233	2,757
Provision for credit losses	15,368	3,822
Amortization of mortgage servicing rights	166	188
Gain on sale of investment securities, net	0	(4,882)
Unrealized loss (gain) on equity securities	18	(18)
Income from bank-owned life insurance policies	(866)	(769)
Net (gain) loss on sale of loans and other assets	(529)	19
Change in other assets and other liabilities	(6,701)	(10,406)
Net cash provided by operating activities	95,355	89,924
Investing activities:
Proceeds from sales of available-for-sale investment securities	0	590,179
Proceeds from maturities, calls, and paydowns of available-for-sale investment securities	130,739	99,105
Proceeds from maturities and redemptions of equity and other investment securities	406	2,537
Purchases of available-for-sale investment securities	(65,211)	(60,826)
Purchases of equity and other securities	(24)	(144)
Net increase in loans	(296,873)	(8,457)
Cash received (paid) for acquisitions, net of cash acquired of $55,973 and $0, respectively	34,360	(1,200)
Purchases of premises and equipment, net	(4,641)	(3,963)
Real estate tax credit investments	(550)	(564)
Net cash (used in) provided by investing activities	(201,794)	616,667
Financing activities:
Net increase in deposits	1,335,437	165,834
Net decrease in borrowings	(83,563)	(171,453)
Issuance of common stock	13,023	1,221
Purchases of treasury stock	(139)	(145)
Sales of treasury stock	85	3,340
Increase in deferred compensation arrangements	139	145
Cash dividends paid	(42,609)	(39,381)
Withholding taxes paid on share-based compensation	(1,084)	(3,150)
Net cash provided by (used in) financing activities	1,221,289	(43,589)
Change in cash and cash equivalents	1,114,850	663,002
Cash and cash equivalents at beginning of period	205,030	211,834
Cash and cash equivalents at end of period	1,319,880	874,836
Supplemental disclosures of cash flow information:
Cash paid for interest	12,336	11,725
Cash paid for income taxes	10,459	21,775
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	22,104	19,663
Transfers from loans to other real estate	990	1,179
Acquisitions:
Common stock issued	76,942	0
Fair value of assets acquired, excluding acquired cash and intangibles	549,983	0
Fair value of liabilities assumed	$ 530,767	$ 0

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Investing activities:
Cash acquired from acquisition	$ 55,973	$ 0

BASIS OF PRESENTATION

BASIS OF PRESENTATION	6 Months Ended
	Jun. 30, 2020
BASIS OF PRESENTATION [Abstract]
BASIS OF PRESENTATION	NOTE A: BASIS OF PRESENTATION The interim financial data as of and for the three and six months ended June 30, 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	6 Months Ended
	Jun. 30, 2020
ACQUISITIONS [Abstract]
ACQUISITIONS	NOTE B: ACQUISITIONS On June 12, 2020, the Company completed its merger with Steuben Trust Corporation (“Steuben”), parent company of Steuben Trust Company, a New York State chartered bank headquartered in Hornell, New York, for $98.6 million in Company stock and cash, comprised of $21.6 million in cash and the issuance of 1.36 million shares of common stock. The merger extends the Company’s footprint into new counties in Western New York State, and enhances the Company’s presence in Western New York State counties in which it currently operates. 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. Goodwill of $40.0 million was recognized as a result of the merger. 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. Prepaid pension, other real estate owned, accrued income taxes, and deferred taxes associated with the Steuben acquisition were recorded on a provisional basis and could vary from the actual recorded balance once finalized. 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 above referenced acquisitions generally expanded the Company’s geographical presence in New York and management expects that the Company will benefit from greater geographic diversity and the advantages of other synergistic business development opportunities. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed after considering the measurement period adjustments described above: 2020 2019 (000s omitted) Steuben Kinderhook Other (1) Total Consideration paid : Cash $ 21,613 $ 93,384 $ 1,650 $ 95,034 Community Bank System, Inc. common stock 76,942 0 0 0 Total net consideration paid 98,555 93,384 1,650 95,034 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 55,973 90,381 0 90,381 Investment securities 180,497 39,770 0 39,770 Loans, net of allowance for credit losses on PCD loans (2) 339,164 479,877 0 479,877 Premises and equipment, net 8,307 13,970 0 13,970 Accrued interest and fees receivable 2,712 1,130 0 1,130 Other assets 19,303 14,109 0 14,109 Core deposit intangibles 2,928 3,573 0 3,573 Other intangibles 1,196 0 1,650 1,650 Deposits (516,269 ) (568,161 ) 0 (568,161 ) Other liabilities (6,436 ) (2,922 ) 0 (2,922 ) Other Federal Home Loan Bank borrowings (6,000 ) (2,420 ) 0 (2,420 ) Subordinated notes payable 0 (13,831 ) 0 (13,831 ) Subordinated debt held by unconsolidated subsidiary trusts (2,062 ) (2,062 ) 0 (2,062 ) Total identifiable assets, net 79,313 53,414 1,650 55,064 Goodwill $ 19,242 $ 39,970 $ 0 $ 39,970 (1) completed by CISI in 2019. (2) Acquisition-related allowance for credit losses on purchased credit deteriorated (“PCD”) loans applicable beginning in 2020 Under ASC 310-30 , acquired On , the Company adopted ASU . , Financial Instruments – Credit Losses (Topic 326 ) which replaces the ASC acquired impaired loans methodology described above with the purchased credit deteriorated (“PCD”) methodology discussed in Note C: Accounting Policies. The Company has acquired loans from Steuben for which there was evidence of a more than insignificant deterioration in credit quality since origination. There were no investment securities acquired from Steuben for which there was evidence of a more than insignificant deterioration in credit quality since origination. The carrying amount of those loans is as follows at the date of acquisition: (000s omitted) PCD Loans Par value of PCD loans at acquisition $ 24,198 Allowance for credit losses at acquisition (528 ) Non-credit discount at acquisition (80 ) Fair value of PCD loans at acquisition $ 23,590 The following is a summary of the remaining loans acquired from Steuben for which there was no evidence of a more-than-insignificant deterioration in credit quality since origination at the date of acquisition: (000s omitted) Non-PCD Loans Contractually required principal and interest at acquisition $ 416,446 Contractual cash flows not expected to be collected (3,177 ) Expected cash flows at acquisition 413,269 Interest component of expected cash flows (97,695 ) Fair value of non-PCD loans at acquisition $ 315,574 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 the Company’s common stock issued for the Steuben acquisition was determined using the market close price of the stock on June 12, 2020. 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 the Steuben acquisition, 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 $3.4 million and $3.7 million during the three and six months ended June 30, 2020, respectively, and have been separately stated in the consolidated statements of income. Merger and acquisition integration-related expenses amount to $1.2 million and $1.7 million during the three and six months ended June 30, 2019, respectively, and have been separately stated in the consolidated statements of income. Supplemental Pro Forma Financial Information The following unaudited condensed pro forma information assumes the Steuben acquisition had been completed as of January 1, 2019 for the three and six months ended June 30, 2020 and June 30, 2019. The table below has been prepared for comparative purposes only and is not necessarily indicative of the actual results that would have been attained had the acquisition occurred as of the beginning of the year presented, nor is it indicative of the Company’s future results. Furthermore, the unaudited pro forma information does not reflect management’s estimate of any revenue-enhancing opportunities nor anticipated cost savings that may have occurred as a result of the integration and consolidation of the acquisitions. The pro forma information set forth below reflects the historical results of Steuben combined with the Company’s consolidated statements of income with adjustments related to (a) certain purchase accounting fair value adjustments and (b) amortization of customer lists and core deposit intangibles. Acquisition-related expenses totaling $3.3 million and $3.6 million for the three and six months ended June 30, 2020 related to Steuben were included in the pro forma information as if they were incurred in the first quarter of 2019. Pro Forma (Unaudited) Three Months Ended Pro Forma (Unaudited) Six Months Ended (000’s omitted) June 30, 2020 June 30, 2019 June 30, 2020 June 30, 2019 Total revenue, net of interest expense $ 149,576 $ 154,878 $ 304,088 $ 303,152 Net income 39,072 46,447 80,848 86,774

ACCOUNTING POLICIES

ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 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 of COVID-19 as of June 30, 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 June 30, 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 June 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 June 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 losses. 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 June 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 June 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. 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 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 Business lending Paycheck Protection Program 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 losses. 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 losses. 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 June 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 did not utilize 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	6 Months Ended
	Jun. 30, 2020
INVESTMENT SECURITIES [Abstract]
INVESTMENT SECURITIES	NOTE D: INVESTMENT SECURITIES The amortized cost and estimated fair value of investment securities as of June 30, 2020 and December 31, 2019 are as follows: June 30, 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 $ 2,048,199 $ 124,122 $ 18 $ 2,172,303 $ 2,030,060 $ 21,674 $ 7,975 $ 2,043,759 Obligations of state and political subdivisions 499,961 21,764 20 521,705 497,852 14,382 26 512,208 Government agency mortgage-backed securities 519,370 15,956 248 535,078 428,491 5,478 1,107 432,862 Corporate debt securities 4,509 68 0 4,577 2,527 1 0 2,528 Government agency collateralized mortgage obligations 57,939 1,520 6 59,453 52,621 482 32 53,071 Total available-for-sale portfolio $ 3,129,978 $ 163,430 $ 292 $ 3,293,116 $ 3,011,551 $ 42,017 $ 9,140 $ 3,044,428 Equity and other Securities: Equity securities, at fair value $ 251 $ 204 $ 22 $ 433 $ 251 $ 200 $ 0 $ 451 Federal Home Loan Bank common stock 7,576 0 0 7,576 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 4,662 750 0 5,412 4,546 750 0 5,296 Total equity and other securities $ 43,411 $ 954 $ 22 $ 44,343 $ 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 June 30, 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: U.S. Treasury and agency securities 8 $ 12,058 $ 18 0 $ 0 $ 0 8 $ 12,058 $ 18 Obligations of state and political subdivisions 52 20,145 20 0 0 0 52 20,145 20 Government agency mortgage-backed securities 142 87,290 248 2 15 0 144 87,305 248 Government agency collateralized mortgage obligations 17 5,346 6 1 0 0 18 5,346 6 Total available-for-sale investment portfolio 219 $ 124,839 $ 292 3 $ 15 $ 0 222 $ 124,854 $ 292 Equity and other Securities: Equity securities, at fair value 1 $ 79 $ 22 0 $ 0 $ 0 1 $ 79 $ 22 Total equity and other securities 1 $ 79 $ 22 0 $ 0 $ 0 1 $ 79 $ 22 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 secondary level of credit enhancement. The Company does not intend to sell these securities, nor is it more likely than not that the Company will be required to sell these securities prior to recovery of the amortized cost. 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 June 30, 2020 represents credit losses and no unrealized losses have been recognized into the provision for credit losses. Accordingly, there is no allowance for credit losses on the Company’s available-for-sale portfolio as of June 30, 2020. As of December 31, 2019, management did not believe any individual unrealized loss represents other-than-temporary impairment. The amortized cost and estimated fair value of debt securities at June 30, 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 $ 663,860 $ 670,059 Due after one through five years 925,191 971,561 Due after five years through ten years 466,983 509,723 Due after ten years 496,635 547,242 Subtotal 2,552,669 2,698,585 Government agency mortgage-backed securities 519,370 535,078 Government agency collateralized mortgage obligations 57,939 59,453 Total $ 3,129,978 $ 3,293,116 As of June 30, 2020, $177.4 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 June 30, 2020 have an overnight and continuous maturity. During the three and six months ended June 30, 2019, the Company sold $590.2 million of U.S. Treasury and agency securities, recognizing $5.0 million of gross realized gains and $0.1 million of gross realized losses.

LOANS

LOANS	6 Months Ended
	Jun. 30, 2020
LOANS [Abstract]
LOANS	NOTE E: LOANS The segments of the Company’s loan portfolio are summarized as follows: (000’s omitted) June 30, 2020 December 31, 2019 Business lending $ 3,455,343 $ 2,775,876 Consumer mortgage 2,428,060 2,430,902 Consumer indirect 1,056,865 1,113,062 Consumer direct 169,228 184,378 Home equity 418,543 386,325 Gross loans, including deferred origination costs 7,528,039 6,890,543 Allowance for credit losses (64,437 ) (49,911 ) Loans, net of allowance for credit losses $ 7,463,602 $ 6,840,632 The following table presents the aging of the amortized cost basis of the Company’s past due loans, including purchased credit deteriorated (“PCD”) loans, by segment as of June 30, 2020: (000’s omitted) Past Due 30 – 89 Days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Current Total Loans Business lending $ 2,495 $ 1,186 $ 5,001 $ 8,682 $ 3,446,661 $ 3,455,343 Consumer mortgage 13,539 3,651 13,544 30,734 2,397,326 2,428,060 Consumer indirect 8,116 744 2 8,862 1,048,003 1,056,865 Consumer direct 875 72 54 1,001 168,227 169,228 Home equity 2,562 410 2,096 5,068 413,475 418,543 Total $ 27,587 $ 6,063 $ 20,697 $ 54,347 $ 7,473,692 $ 7,528,039 The following is an aged analysis of the Company’s past due loans by segment 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 June 30, 2020 based on their delinquency status at the end of the first quarter, unless subsequent to March 31, 2020, the borrower made all required past due payments to bring the loan to current status. No interest income on nonaccrual loans was recognized during the three and six months ended June 30, 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 Doubtful The The following tables show the amount of business lending loans by credit quality category at June 30, 2020 and December 31, 2019: (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year Revolving Loans Amortized June 30, 2020 2020 2019 2018 2017 2016 Prior Cost Basis Total Business lending: Risk rating Pass $ 661,019 $ 390,621 $ 371,073 $ 273,598 $ 274,860 $ 634,379 $ 567,034 $ 3,172,584 Special mention 6,026 12,045 6,641 12,701 18,005 56,168 30,485 142,071 Classified 3,334 3,056 17,362 8,151 15,286 55,677 37,822 140,688 Doubtful 0 0 0 0 0 0 0 0 Total business lending $ 670,379 $ 405,722 $ 395,076 $ 294,450 $ 308,151 $ 746,224 $ 635,341 $ 3,455,343 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 June : (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year Revolving Loans Amortized June 30, 2020 2020 2019 2018 2017 2016 Prior Cost Basis Total Consumer mortgage: FICO AB Performing $ 111,491 $ 247,646 $ 186,686 $ 185,064 $ 178,459 $ 712,049 $ 454 $ 1,621,849 Nonperforming 0 155 151 408 317 3,449 0 4,480 Total FICO AB 111,491 247,801 186,837 185,472 178,776 715,498 454 1,626,329 FICO CDE Performing 47,370 108,296 85,917 83,641 91,733 362,287 9,772 789,016 Nonperforming 0 360 732 674 1,456 9,493 0 12,715 Total FICO CDE 47,370 108,656 86,649 84,315 93,189 371,780 9,772 801,731 Total consumer mortgage $ 158,861 $ 356,457 $ 273,486 $ 269,787 $ 271,965 $ 1,087,278 $ 10,226 $ 2,428,060 Consumer indirect: Performing $ 135,333 $ 372,290 $ 260,629 $ 118,119 $ 88,554 $ 81,194 $ 0 $ 1,056,119 Nonperforming 9 170 176 175 137 79 0 746 Total consumer indirect $ 135,342 $ 372,460 $ 260,805 $ 118,294 $ 88,691 $ 81,273 0 $ 1,056,865 Consumer direct: Performing $ 27,668 $ 60,954 $ 38,348 $ 18,528 $ 8,888 $ 7,892 $ 6,824 $ 169,102 Nonperforming 0 35 23 66 0 0 2 126 Total consumer direct $ 27,668 $ 60,989 $ 38,371 $ 18,594 $ 8,888 $ 7,892 $ 6,826 $ 169,228 Home equity: Performing $ 31,060 $ 53,585 $ 31,703 $ 26,694 $ 21,831 $ 40,438 $ 210,726 $ 416,037 Nonperforming 0 0 0 65 165 644 1,632 2,506 Total home equity $ 31,060 $ 53,585 $ 31,703 $ 26,759 $ 21,996 $ 41,082 $ 212,358 $ 418,543 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 loans as of June 30, 2020 and December 31, 2019 follows: (000’s omitted) June 30, 2020 December 31, 2019 Loans with allowance allocation $ 0 $ 0 Loans without allowance allocation 1,414 1,414 Carrying balance 1,414 1,414 Contractual balance 2,943 2,944 Specifically allocated allowance 0 0 The average carrying balance of individually evaluated impaired loans was $1.4 million and $5.1 million for the three months ended June 30, 2020 and June 30, 2019, respectively. The average carrying balance of individually evaluated impaired loans was $1.8 million and $5.6 million for the six months ended June 30, 2020 and June 30, 2019, respectively. No interest income was recognized on individually evaluated impaired loans for the three or six months ended June 30, 2020 and June 30, 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 and six months ended June 30, 2020 and 2019 was immaterial . TDRs that are less than $ million $ million are 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 six months 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 six months of 2020. 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 June 30, 2020 and December 31, 2019 is as follows: June 30, 2020 December 31, 2019 (000’s omitted) Nonaccrual Accruing Total Nonaccrual Accruing Total # Amount # Amount # Amount # Amount # Amount # Amount Business lending 8 $ 602 3 $ 195 11 $ 797 8 $ 681 3 $ 201 11 $ 882 Consumer mortgage 58 2,491 47 2,230 105 4,721 59 2,638 47 1,892 106 4,530 Consumer indirect 0 0 79 878 79 878 0 0 84 941 84 941 Consumer direct 0 0 23 99 23 99 0 0 23 101 23 101 Home equity 11 285 10 250 21 535 13 290 11 238 24 528 Total 77 $ 3,378 162 $ 3,652 239 $ 7,030 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 and six months ended June 30, 2020 and 2019. Of the loans noted in the table below, all consumer mortgage loans for the three months and six months ended June 30, 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 June 30, 2020 Three Months Ended June 30, 2019 (000’s omitted) Number of loans modified Outstanding Balance Number of loans modified Outstanding Balance Business lending 0 $ 0 2 $ 250 Consumer mortgage 3 174 4 283 Consumer indirect 3 47 4 33 Consumer direct 0 0 2 6 Home equity 1 28 3 71 Total 7 $ 249 15 $ 643 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (000’s omitted) Number of loans modified Outstanding Balance Number of loans modified Outstanding Balance Business lending 0 $ 0 2 $ 250 Consumer mortgage 9 738 11 861 Consumer indirect 14 151 12 98 Consumer direct 1 11 3 12 Home equity 1 28 4 75 Total 25 $ 928 32 $ 1,296 Allowance for Credit Losses The following presents by segment the activity in the allowance for credit losses: Three Months Ended June 30, 2020 (000’s omitted) Beginning balance Charge-offs Recoveries Steuben acquisition Provision Ending balance Business lending $ 19,489 $ (7 ) $ 84 $ 2,483 $ 2,155 $ 24,204 Consumer mortgage 12,430 (234 ) 36 146 710 13,088 Consumer indirect 13,694 (1,431 ) 833 183 2,587 15,866 Consumer direct 3,737 (341 ) 171 87 374 4,028 Home equity 2,484 (81 ) 12 235 40 2,690 Unallocated 772 0 0 0 228 1,000 Purchased credit deteriorated 3,046 0 48 528 (61 ) 3,561 Allowance for credit losses – loans 55,652 (2,094 ) 1,184 3,662 6,033 64,437 Liabilities for off-balance-sheet credit exposures 845 0 0 67 540 1,452 Total allowance for credit losses $ 56,497 $ (2,094 ) $ 1,184 $ 3,729 $ 6,573 $ 65,889 Three Months Ended June 30, 2019 (000’s omitted) Business Lending Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Unallocated Acquired Impaired Total Beginning balance $ 18,271 $ 10,317 $ 14,251 $ 3,056 $ 2,067 $ 990 $ 155 $ 49,107 Charge-offs (253 ) (587 ) (1,482 ) (445 ) (104 ) 0 0 (2,871 ) Recoveries 169 14 1,239 221 31 0 0 1,674 Provision (418 ) 1,019 337 352 109 1 0 1,400 Ending balance $ 17,769 $ 10,763 $ 14,345 $ 3,184 $ 2,103 $ 991 $ 155 $ 49,310 Six Months Ended June 30, 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 Steuben acquisition Provision Ending balance Business lending $ 19,426 $ 288 $ 19,714 $ (183 ) $ 222 $ 2,483 $ 1,968 $ 24,204 Consumer mortgage 10,269 (1,051 ) 9,218 (420 ) 44 146 4,100 13,088 Consumer indirect 13,712 (997 ) 12,715 (3,510 ) 1,996 183 4,482 15,866 Consumer direct 3,255 (643 ) 2,612 (874 ) 353 87 1,850 4,028 Home equity 2,129 808 2,937 (154 ) 18 235 (346 ) 2,690 Unallocated 957 43 1,000 0 0 0 0 1,000 Purchased credit deteriorated 0 3,072 3,072 0 48 528 (87 ) 3,561 Purchased credit impaired 163 (163 ) 0 0 0 0 0 0 Allowance for credit losses – loans 49,911 1,357 51,268 (5,141 ) 2,681 3,662 11,967 64,437 Liabilities for off-balance-sheet credit exposures 0 1,185 1,185 0 0 67 200 1,452 Total allowance for credit losses $ 49,911 $ 2,542 $ 52,453 $ (5,141 ) $ 2,681 $ 3,729 $ 12,167 $ 65,889 Six Months Ended June 30, 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 (1,469 ) (840 ) (3,305 ) (980 ) (178 ) 0 0 (6,772 ) Recoveries 303 36 2,201 400 36 0 0 2,976 Provision 413 1,443 1,083 669 101 (9 ) 122 3,822 Ending balance $ 17,769 $ 10,763 $ 14,345 $ 3,184 $ 2,103 $ 991 $ 155 $ 49,310 The decline in economic conditions associated with the COVID-19 pandemic have resulted in an allowance for credit losses to total loans ratio of 0.86% at June 30, 2020, eight basis points higher than the level at June 30, 2019 and 14 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 July 10, 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 a continued weakness in economic activity with peak unemployment ranging from 9% to 12% in the third quarter of 2021 and a general improvement in unemployment levels over the subsequent three 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 unemployment and 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. The following table presents the carrying amounts of loans purchased and sold during the six months ended June 30, 2020 by portfolio segment: (000’s omitted) Business lending Consumer mortgage Consumer indirect Consumer direct Home equity Total Purchases $ 253,469 $ 26,733 $ 13,926 $ 6,022 $ 39,542 $ 339,692 Sales 0 15,599 0 0 0 15,599 All the purchases during the six months ended June 30, 2020 were associated with the Steuben acquisition on June 12, 2020 and all the sales during the six months ended June 30, 2020 were sales of secondary market eligible residential mortgage loans.

GOODWILL AND IDENTIFIABLE INTAN

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	6 Months Ended
	Jun. 30, 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: June 30, 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 $ 69,403 $ (52,838 ) $ 16,565 $ 66,475 $ (50,057 ) $ 16,418 Other intangibles 90,462 (46,981 ) 43,481 89,266 (42,571 ) 46,695 Total amortizing intangibles $ 159,865 $ (99,819 ) $ 60,046 $ 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) Jul - Dec 2020 $ 7,106 2021 12,640 2022 10,844 2023 9,082 2024 7,551 Thereafter 12,823 Total $ 60,046 Shown below are the components of the Company’s goodwill at December 31, 2019 and June 30, 2020: (000’s omitted) December 31, 2019 Activity June 30, 2020 Goodwill, net $ 773,810 $ 18,905 $ 792,715

MANDATORILY REDEEMABLE PREFERRE

MANDATORILY REDEEMABLE PREFERRED SECURITIES	6 Months Ended
	Jun. 30, 2020
MANDATORILY REDEEMABLE PREFERRED SECURITIES [Abstract]
MANDATORILY REDEEMABLE PREFERRED SECURITIES	NOTE G: MANDATORILY REDEEMABLE PREFERRED SECURITIES As of June 30, 2020, the Company sponsors business trusts, Community Capital Trust IV (“CCT IV”) and Steuben Statutory Trust II (“SST II”), of which of the common stock is owned by the Company. The common stock of Steuben Statutory Trust II was acquired in the Steuben acquisition. 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 June 30, 2020, the terms of the preferred securities of each trust are as follows: Trust Issuance Date Par Amount Interest Rate Maturity Date Call Price CCT IV 12/8/2006 $75.0 million 3 month LIBOR plus 1.65% (1.96%) 12/15/2036 Par SST II 07/16/2007 $2.0 million 3 month LIBOR plus 1.55% (1.86%) 09/15/2037 Par

BENEFIT PLANS

BENEFIT PLANS	6 Months Ended
	Jun. 30, 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 $ million contribution to its defined benefit pension plan in the second quarter of 2020 The net periodic benefit cost for the three and six months ended June 30, 2020 and 2019 is as follows: Pension Benefits Post-retirement Benefits Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (000’s omitted) 2020 2019 2020 2019 2020 2019 2020 2019 Service cost $ 1,438 $ 1,270 $ 2,875 $ 2,540 $ 0 $ 0 $ 0 $ 0 Interest cost 1,356 1,565 2,712 3,133 14 18 28 35 Expected return on plan assets (3,932 ) (3,578 ) (7,864 ) (7,155 ) 0 0 0 0 Amortization of unrecognized net loss 810 643 1,620 1,284 10 9 20 19 Amortization of prior service cost 60 16 120 31 (44 ) (45 ) (89 ) (89 ) Net periodic benefit $ (268 ) $ (84 ) $ (537 ) $ (167 ) $ (20 ) $ (18 ) $ (41 ) $ (35 )

EARNINGS PER SHARE

EARNINGS PER SHARE	6 Months Ended
	Jun. 30, 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 June 30, 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 (those where the average market price is greater than the exercise price) were exercised and the proceeds were used to repurchase common shares in the open market at the average market price for the applicable time period. There were approximately 0.6 million weighted-average anti-dilutive stock options outstanding for the three months and six months ended June 30, 2020, compared to million weighted-average anti-dilutive stock options outstanding for the three months and six months ended June 30, 2019 that were not included in the computation below. The following is a reconciliation of basic to diluted earnings per share for the three and six months ended June 30, 2020 and 2019: Three Months Ended Six Months Ended June 30, June 30, (000’s omitted, except per share data) 2020 2019 2020 2019 Net income $ 35,248 $ 45,015 $ 75,382 $ 86,961 Income attributable to unvested stock-based compensation awards (127 ) (146 ) (264 ) (255 ) Income available to common shareholders $ 35,121 $ 44,869 $ 75,118 $ 86,706 Weighted-average common shares outstanding – basic 52,487 51,659 52,262 51,590 Basic earnings per share $ 0.67 $ 0.87 $ 1.44 $ 1.68 Net income $ 35,248 $ 45,015 $ 75,382 $ 86,961 Income attributable to unvested stock-based compensation awards (127 ) (146 ) (264 ) (255 ) Income available to common shareholders $ 35,121 $ 44,869 $ 75,118 $ 86,706 Weighted-average common shares outstanding – basic 52,487 51,659 52,262 51,590 Assumed exercise of stock options 339 529 372 535 Weighted-average common shares outstanding – diluted 52,826 52,188 52,634 52,125 Diluted earnings per share $ 0.66 $ 0.86 $ 1.43 $ 1.66 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 six months of 2020 or 2019

COMMITMENTS, CONTINGENT LIABILI

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS	6 Months Ended
	Jun. 30, 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) June 30, 2020 December 31, 2019 Commitments to extend credit $ 1,142,557 $ 1,143,780 Standby letters of credit 39,466 37,872 Total $ 1,182,023 $ 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 June 30, 2020

FAIR VALUE

FAIR VALUE	6 Months Ended
	Jun. 30, 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. June 30, 2020 (000’s omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,989,069 $ 183,234 $ 0 $ 2,172,303 Obligations of state and political subdivisions 0 521,705 0 521,705 Government agency mortgage-backed securities 0 535,078 0 535,078 Corporate debt securities 0 4,577 0 4,577 Government agency collateralized mortgage obligations 0 59,453 0 59,453 Total available-for-sale investment securities 1,989,069 1,304,047 0 3,293,116 Equity securities 433 0 0 433 Mortgage loans held for sale 0 5,517 0 5,517 Commitments to originate real estate loans for sale 0 0 859 859 Forward sales commitments 0 83 0 83 Interest rate swap agreements asset 0 1,882 0 1,882 Interest rate swap agreements liability 0 (1,289 ) 0 (1,289 ) Total $ 1,989,502 $ 1,310,240 $ 859 $ 3,300,601 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 $4.3 million at June 30, 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. June 30, 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 3,186 3,186 0 0 1,270 1,270 Mortgage servicing rights 0 0 122 122 0 0 56 56 Total $ 0 $ 0 $ 4,156 $ 4,156 $ 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 credit losses. Such amounts are generally based on the fair value of the underlying collateral supporting the loan and, as a result, the carrying value of the loan less the calculated valuation amount does not necessarily represent the fair value of the loan. Real estate collateral is typically valued using independent appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace, adjusted for non-observable inputs. Thus, the resulting nonrecurring fair value measurements are generally classified as Level 3. Estimates of fair value used for other collateral supporting commercial loans generally are based on assumptions not observable in the marketplace and, therefore, such valuations are classified 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 9.4% to 85.7% at June 30, 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 June 30, 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 3,186 Fair value of collateral Estimated cost of disposal/market adjustment 9.4% - 85.7% (26.5 %) Commitments to originate real estate loans for sale 859 Discounted cash flow Embedded servicing value 1.0 % Mortgage servicing rights 122 Discounted cash flow Weighted average constant prepayment rate 52.8 % Weighted average discount rate 1.93 % 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 June 30, 2020 and December 31, 2019 are as follows: June 30, 2020 December 31, 2019 (000’s omitted) Carrying Value Fair Value Carrying Value Fair Value Financial assets: Net loans $ 7,463,602 $ 7,801,009 $ 6,840,632 $ 7,028,663 Financial liabilities: Deposits 10,846,673 10,864,309 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 168,491 168,491 241,708 241,708 Other Federal Home Loan Bank borrowings 7,704 7,860 3,750 3,755 Subordinated notes payable 13,755 13,755 13,795 13,795 Subordinated debt held by unconsolidated subsidiary trusts 79,382 79,382 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	6 Months Ended
	Jun. 30, 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 June 30, 2020 and December 31, 2019. The effect of the changes to these derivatives for the three and six months . The Company acquired interest rate swaps in 2017 with notional amounts with certain commercial customers which totaled $ million at June 30, 2020 and $ 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 $ million at June 30, 2020 and $ million at December 31, 2019. At June 30, 2020, the weighted average receive rate of these interest rate swaps was , the weighted average pay rate was and the weighted average maturity was years. At December 31, 2019, the weighted average receive rate of these interest rate swaps was , the weighted average pay rate was and the weighted average maturity was years. Hedge accounting has not been applied for these derivatives. The Company also acquired interest rate swaps in 2017 with notional amounts totaling $5.8 million at June 30, 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 condition. At June 30, 2020, the weighted average receive rate of these interest rate swaps was 1.45%, the weighted average pay rate was 3.11% and the weighted average maturity was 13.0 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 statements of income for the three and six months ended June 30, 2020 are immaterial. As of June 30, 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 June 30, 2020 December 31, 2019 June 30, 2020 December 31, 2019 Loans $ 5,653 $ 6,390 $ (593) $ (265) Fair values of derivative instruments as of June 30, 2020 and December 31, 2019 are as follows: (000’s omitted) June 30, 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 $ 593 Derivatives not designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets 1,289 Accrued interest and other liabilities $ 1,289 Commitments to originate real estate loans for sale Other assets 859 Forward sales commitments Other assets 83 Total derivatives $ 2,824 $ 1,289 (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 June 30, 2020 and December 31, 2019 and determined any credit risk inherent in our derivative contracts was not material. Information about the fair value of derivative financial instruments can be found in Note K to these consolidated financial statements.

SEGMENT INFORMATION

SEGMENT INFORMATION	6 Months Ended
	Jun. 30, 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, The Carta Group, Inc. and OneGroup Wealth Partners, 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 June 30, 2020 Net interest income $ 91,645 $ 246 $ 60 $ 0 $ 91,951 Provision for credit losses 9,774 0 0 0 9,774 Noninterest revenues 14,991 24,504 14,817 (1,374 ) 52,938 Amortization of intangible assets 1,364 1,411 749 0 3,524 Acquisition expenses 3,372 0 0 0 3,372 Other operating expenses 59,130 14,948 11,303 (1,374 ) 84,007 Income before income taxes $ 32,996 $ 8,391 $ 2,825 $ 0 $ 44,212 Assets $ 13,272,929 $ 216,122 $ 78,022 $ (122,856 ) $ 13,444,217 Goodwill $ 689,128 $ 83,275 $ 20,312 $ 0 $ 792,715 Core deposit intangibles & Other intangibles $ 16,565 $ 34,870 $ 8,611 $ 0 $ 60,046 Three Months Ended June 30, 2019 Net interest income $ 88,127 $ 131 $ 42 $ 0 $ 88,300 Provision for credit losses 1,400 0 0 0 1,400 Noninterest revenues 21,921 24,839 15,159 (1,213 ) 60,706 Amortization of intangible assets 1,375 1,669 860 0 3,904 Acquisition expenses 1,194 0 0 0 1,194 Other operating expenses 60,578 15,405 11,308 (1,213 ) 86,078 Income before income taxes $ 45,501 $ 7,896 $ 3,033 $ 0 $ 56,430 Assets $ 10,534,555 $ 206,178 $ 72,862 $ (68,207 ) $ 10,745,388 Goodwill $ 629,916 $ 83,275 $ 20,312 $ 0 $ 733,503 Core deposit intangibles & Other intangibles $ 15,738 $ 41,107 $ 10,167 $ 0 $ 67,012 (000’s omitted) Banking Employee Benefit Services All Other Eliminations Consolidated Total Six Months Ended June 30, 2020 Net interest income $ 181,409 $ 486 $ 110 $ 0 $ 182,005 Provision for credit losses 15,368 0 0 0 15,368 Noninterest revenues 33,672 50,429 30,352 (2,893 ) 111,560 Amortization of intangible assets 2,781 2,905 1,505 0 7,191 Acquisition expenses 3,741 0 0 0 3,741 Other operating expenses 123,330 30,079 23,118 (2,893 ) 173,634 Income before income taxes $ 69,861 $ 17,931 $ 5,839 $ 0 $ 93,631 Six Months Ended June 30, 2019 Net interest income $ 174,842 $ 239 $ 78 $ 0 $ 175,159 Provision for credit losses 3,822 0 0 0 3,822 Noninterest revenues 39,269 49,509 29,606 (1,982 ) 116,402 Amortization of intangible assets 2,858 3,438 1,738 0 8,034 Acquisition expenses 1,728 0 0 0 1,728 Other operating expenses 120,347 29,684 22,017 (1,982 ) 170,066 Income before income taxes $ 85,356 $ 16,626 $ 5,929 $ 0 $ 107,911

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	6 Months Ended
	Jun. 30, 2020
BASIS OF PRESENTATION [Abstract]
Basis of Presentation	The interim financial data as of and for the three and six months ended June 30, 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)	6 Months Ended
	Jun. 30, 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 June 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 June 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 losses. 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 June 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 June 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. 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 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 Business lending Paycheck Protection Program 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 losses. 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 losses.
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 June 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 did not utilize 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)	6 Months Ended
	Jun. 30, 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: 2020 2019 (000s omitted) Steuben Kinderhook Other (1) Total Consideration paid : Cash $ 21,613 $ 93,384 $ 1,650 $ 95,034 Community Bank System, Inc. common stock 76,942 0 0 0 Total net consideration paid 98,555 93,384 1,650 95,034 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash and cash equivalents 55,973 90,381 0 90,381 Investment securities 180,497 39,770 0 39,770 Loans, net of allowance for credit losses on PCD loans (2) 339,164 479,877 0 479,877 Premises and equipment, net 8,307 13,970 0 13,970 Accrued interest and fees receivable 2,712 1,130 0 1,130 Other assets 19,303 14,109 0 14,109 Core deposit intangibles 2,928 3,573 0 3,573 Other intangibles 1,196 0 1,650 1,650 Deposits (516,269 ) (568,161 ) 0 (568,161 ) Other liabilities (6,436 ) (2,922 ) 0 (2,922 ) Other Federal Home Loan Bank borrowings (6,000 ) (2,420 ) 0 (2,420 ) Subordinated notes payable 0 (13,831 ) 0 (13,831 ) Subordinated debt held by unconsolidated subsidiary trusts (2,062 ) (2,062 ) 0 (2,062 ) Total identifiable assets, net 79,313 53,414 1,650 55,064 Goodwill $ 19,242 $ 39,970 $ 0 $ 39,970 (1) completed by CISI in 2019. (2) Acquisition-related allowance for credit losses on purchased credit deteriorated (“PCD”) loans applicable beginning in 2020
Loans Acquired	The Company has acquired loans from Steuben for which there was evidence of a more than insignificant deterioration in credit quality since origination. There were no investment securities acquired from Steuben for which there was evidence of a more than insignificant deterioration in credit quality since origination. The carrying amount of those loans is as follows at the date of acquisition: (000s omitted) PCD Loans Par value of PCD loans at acquisition $ 24,198 Allowance for credit losses at acquisition (528 ) Non-credit discount at acquisition (80 ) Fair value of PCD loans at acquisition $ 23,590 The following is a summary of the remaining loans acquired from Steuben for which there was no evidence of a more-than-insignificant deterioration in credit quality since origination at the date of acquisition: (000s omitted) Non-PCD Loans Contractually required principal and interest at acquisition $ 416,446 Contractual cash flows not expected to be collected (3,177 ) Expected cash flows at acquisition 413,269 Interest component of expected cash flows (97,695 ) Fair value of non-PCD loans at acquisition $ 315,574 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
Pro Forma Financial Information	The pro forma information set forth below reflects the historical results of Steuben combined with the Company’s consolidated statements of income with adjustments related to (a) certain purchase accounting fair value adjustments and (b) amortization of customer lists and core deposit intangibles. Acquisition-related expenses totaling $3.3 million and $3.6 million for the three and six months ended June 30, 2020 related to Steuben were included in the pro forma information as if they were incurred in the first quarter of 2019. Pro Forma (Unaudited) Three Months Ended Pro Forma (Unaudited) Six Months Ended (000’s omitted) June 30, 2020 June 30, 2019 June 30, 2020 June 30, 2019 Total revenue, net of interest expense $ 149,576 $ 154,878 $ 304,088 $ 303,152 Net income 39,072 46,447 80,848 86,774

INVESTMENT SECURITIES (Tables)

INVESTMENT SECURITIES (Tables)	6 Months Ended
	Jun. 30, 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 June 30, 2020 and December 31, 2019 are as follows: June 30, 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 $ 2,048,199 $ 124,122 $ 18 $ 2,172,303 $ 2,030,060 $ 21,674 $ 7,975 $ 2,043,759 Obligations of state and political subdivisions 499,961 21,764 20 521,705 497,852 14,382 26 512,208 Government agency mortgage-backed securities 519,370 15,956 248 535,078 428,491 5,478 1,107 432,862 Corporate debt securities 4,509 68 0 4,577 2,527 1 0 2,528 Government agency collateralized mortgage obligations 57,939 1,520 6 59,453 52,621 482 32 53,071 Total available-for-sale portfolio $ 3,129,978 $ 163,430 $ 292 $ 3,293,116 $ 3,011,551 $ 42,017 $ 9,140 $ 3,044,428 Equity and other Securities: Equity securities, at fair value $ 251 $ 204 $ 22 $ 433 $ 251 $ 200 $ 0 $ 451 Federal Home Loan Bank common stock 7,576 0 0 7,576 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 4,662 750 0 5,412 4,546 750 0 5,296 Total equity and other securities $ 43,411 $ 954 $ 22 $ 44,343 $ 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 June 30, 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: U.S. Treasury and agency securities 8 $ 12,058 $ 18 0 $ 0 $ 0 8 $ 12,058 $ 18 Obligations of state and political subdivisions 52 20,145 20 0 0 0 52 20,145 20 Government agency mortgage-backed securities 142 87,290 248 2 15 0 144 87,305 248 Government agency collateralized mortgage obligations 17 5,346 6 1 0 0 18 5,346 6 Total available-for-sale investment portfolio 219 $ 124,839 $ 292 3 $ 15 $ 0 222 $ 124,854 $ 292 Equity and other Securities: Equity securities, at fair value 1 $ 79 $ 22 0 $ 0 $ 0 1 $ 79 $ 22 Total equity and other securities 1 $ 79 $ 22 0 $ 0 $ 0 1 $ 79 $ 22 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 June 30, 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 $ 663,860 $ 670,059 Due after one through five years 925,191 971,561 Due after five years through ten years 466,983 509,723 Due after ten years 496,635 547,242 Subtotal 2,552,669 2,698,585 Government agency mortgage-backed securities 519,370 535,078 Government agency collateralized mortgage obligations 57,939 59,453 Total $ 3,129,978 $ 3,293,116

LOANS (Tables)

LOANS (Tables)	6 Months Ended
	Jun. 30, 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) June 30, 2020 December 31, 2019 Business lending $ 3,455,343 $ 2,775,876 Consumer mortgage 2,428,060 2,430,902 Consumer indirect 1,056,865 1,113,062 Consumer direct 169,228 184,378 Home equity 418,543 386,325 Gross loans, including deferred origination costs 7,528,039 6,890,543 Allowance for credit losses (64,437 ) (49,911 ) Loans, net of allowance for credit losses $ 7,463,602 $ 6,840,632
Aged Analysis of Past Due Loans by Segment	The following table presents the aging of the amortized cost basis of the Company’s past due loans, including purchased credit deteriorated (“PCD”) loans, by segment as of June 30, 2020: (000’s omitted) Past Due 30 – 89 Days 90+ Days Past Due and Still Accruing Nonaccrual Total Past Due Current Total Loans Business lending $ 2,495 $ 1,186 $ 5,001 $ 8,682 $ 3,446,661 $ 3,455,343 Consumer mortgage 13,539 3,651 13,544 30,734 2,397,326 2,428,060 Consumer indirect 8,116 744 2 8,862 1,048,003 1,056,865 Consumer direct 875 72 54 1,001 168,227 169,228 Home equity 2,562 410 2,096 5,068 413,475 418,543 Total $ 27,587 $ 6,063 $ 20,697 $ 54,347 $ 7,473,692 $ 7,528,039 The following is an aged analysis of the Company’s past due loans by segment 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 loans as of June 30, 2020 and December 31, 2019 follows: (000’s omitted) June 30, 2020 December 31, 2019 Loans with allowance allocation $ 0 $ 0 Loans without allowance allocation 1,414 1,414 Carrying balance 1,414 1,414 Contractual balance 2,943 2,944 Specifically allocated allowance 0 0
Troubled Debt Restructurings on Financing Receivables	Information regarding TDRs as of June 30, 2020 and December 31, 2019 is as follows: June 30, 2020 December 31, 2019 (000’s omitted) Nonaccrual Accruing Total Nonaccrual Accruing Total # Amount # Amount # Amount # Amount # Amount # Amount Business lending 8 $ 602 3 $ 195 11 $ 797 8 $ 681 3 $ 201 11 $ 882 Consumer mortgage 58 2,491 47 2,230 105 4,721 59 2,638 47 1,892 106 4,530 Consumer indirect 0 0 79 878 79 878 0 0 84 941 84 941 Consumer direct 0 0 23 99 23 99 0 0 23 101 23 101 Home equity 11 285 10 250 21 535 13 290 11 238 24 528 Total 77 $ 3,378 162 $ 3,652 239 $ 7,030 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 and six months ended June 30, 2020 and 2019. Of the loans noted in the table below, all consumer mortgage loans for the three months and six months ended June 30, 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 June 30, 2020 Three Months Ended June 30, 2019 (000’s omitted) Number of loans modified Outstanding Balance Number of loans modified Outstanding Balance Business lending 0 $ 0 2 $ 250 Consumer mortgage 3 174 4 283 Consumer indirect 3 47 4 33 Consumer direct 0 0 2 6 Home equity 1 28 3 71 Total 7 $ 249 15 $ 643 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 (000’s omitted) Number of loans modified Outstanding Balance Number of loans modified Outstanding Balance Business lending 0 $ 0 2 $ 250 Consumer mortgage 9 738 11 861 Consumer indirect 14 151 12 98 Consumer direct 1 11 3 12 Home equity 1 28 4 75 Total 25 $ 928 32 $ 1,296
Allowance for Credit Losses by Class	The following presents by segment the activity in the allowance for credit losses: Three Months Ended June 30, 2020 (000’s omitted) Beginning balance Charge-offs Recoveries Steuben acquisition Provision Ending balance Business lending $ 19,489 $ (7 ) $ 84 $ 2,483 $ 2,155 $ 24,204 Consumer mortgage 12,430 (234 ) 36 146 710 13,088 Consumer indirect 13,694 (1,431 ) 833 183 2,587 15,866 Consumer direct 3,737 (341 ) 171 87 374 4,028 Home equity 2,484 (81 ) 12 235 40 2,690 Unallocated 772 0 0 0 228 1,000 Purchased credit deteriorated 3,046 0 48 528 (61 ) 3,561 Allowance for credit losses – loans 55,652 (2,094 ) 1,184 3,662 6,033 64,437 Liabilities for off-balance-sheet credit exposures 845 0 0 67 540 1,452 Total allowance for credit losses $ 56,497 $ (2,094 ) $ 1,184 $ 3,729 $ 6,573 $ 65,889 Three Months Ended June 30, 2019 (000’s omitted) Business Lending Consumer Mortgage Consumer Indirect Consumer Direct Home Equity Unallocated Acquired Impaired Total Beginning balance $ 18,271 $ 10,317 $ 14,251 $ 3,056 $ 2,067 $ 990 $ 155 $ 49,107 Charge-offs (253 ) (587 ) (1,482 ) (445 ) (104 ) 0 0 (2,871 ) Recoveries 169 14 1,239 221 31 0 0 1,674 Provision (418 ) 1,019 337 352 109 1 0 1,400 Ending balance $ 17,769 $ 10,763 $ 14,345 $ 3,184 $ 2,103 $ 991 $ 155 $ 49,310 Six Months Ended June 30, 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 Steuben acquisition Provision Ending balance Business lending $ 19,426 $ 288 $ 19,714 $ (183 ) $ 222 $ 2,483 $ 1,968 $ 24,204 Consumer mortgage 10,269 (1,051 ) 9,218 (420 ) 44 146 4,100 13,088 Consumer indirect 13,712 (997 ) 12,715 (3,510 ) 1,996 183 4,482 15,866 Consumer direct 3,255 (643 ) 2,612 (874 ) 353 87 1,850 4,028 Home equity 2,129 808 2,937 (154 ) 18 235 (346 ) 2,690 Unallocated 957 43 1,000 0 0 0 0 1,000 Purchased credit deteriorated 0 3,072 3,072 0 48 528 (87 ) 3,561 Purchased credit impaired 163 (163 ) 0 0 0 0 0 0 Allowance for credit losses – loans 49,911 1,357 51,268 (5,141 ) 2,681 3,662 11,967 64,437 Liabilities for off-balance-sheet credit exposures 0 1,185 1,185 0 0 67 200 1,452 Total allowance for credit losses $ 49,911 $ 2,542 $ 52,453 $ (5,141 ) $ 2,681 $ 3,729 $ 12,167 $ 65,889 Six Months Ended June 30, 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 (1,469 ) (840 ) (3,305 ) (980 ) (178 ) 0 0 (6,772 ) Recoveries 303 36 2,201 400 36 0 0 2,976 Provision 413 1,443 1,083 669 101 (9 ) 122 3,822 Ending balance $ 17,769 $ 10,763 $ 14,345 $ 3,184 $ 2,103 $ 991 $ 155 $ 49,310
Carrying Amounts of Loans Purchased and Sold	The following table presents the carrying amounts of loans purchased and sold during the six months ended June 30, 2020 by portfolio segment: (000’s omitted) Business lending Consumer mortgage Consumer indirect Consumer direct Home equity Total Purchases $ 253,469 $ 26,733 $ 13,926 $ 6,022 $ 39,542 $ 339,692 Sales 0 15,599 0 0 0 15,599
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 June 30, 2020 and December 31, 2019: (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year Revolving Loans Amortized June 30, 2020 2020 2019 2018 2017 2016 Prior Cost Basis Total Business lending: Risk rating Pass $ 661,019 $ 390,621 $ 371,073 $ 273,598 $ 274,860 $ 634,379 $ 567,034 $ 3,172,584 Special mention 6,026 12,045 6,641 12,701 18,005 56,168 30,485 142,071 Classified 3,334 3,056 17,362 8,151 15,286 55,677 37,822 140,688 Doubtful 0 0 0 0 0 0 0 0 Total business lending $ 670,379 $ 405,722 $ 395,076 $ 294,450 $ 308,151 $ 746,224 $ 635,341 $ 3,455,343 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	The following table details the balances in all other loan categories at June : (000 ’s omitted) Term Loans Amortized Cost Basis by Origination Year Revolving Loans Amortized June 30, 2020 2020 2019 2018 2017 2016 Prior Cost Basis Total Consumer mortgage: FICO AB Performing $ 111,491 $ 247,646 $ 186,686 $ 185,064 $ 178,459 $ 712,049 $ 454 $ 1,621,849 Nonperforming 0 155 151 408 317 3,449 0 4,480 Total FICO AB 111,491 247,801 186,837 185,472 178,776 715,498 454 1,626,329 FICO CDE Performing 47,370 108,296 85,917 83,641 91,733 362,287 9,772 789,016 Nonperforming 0 360 732 674 1,456 9,493 0 12,715 Total FICO CDE 47,370 108,656 86,649 84,315 93,189 371,780 9,772 801,731 Total consumer mortgage $ 158,861 $ 356,457 $ 273,486 $ 269,787 $ 271,965 $ 1,087,278 $ 10,226 $ 2,428,060 Consumer indirect: Performing $ 135,333 $ 372,290 $ 260,629 $ 118,119 $ 88,554 $ 81,194 $ 0 $ 1,056,119 Nonperforming 9 170 176 175 137 79 0 746 Total consumer indirect $ 135,342 $ 372,460 $ 260,805 $ 118,294 $ 88,691 $ 81,273 0 $ 1,056,865 Consumer direct: Performing $ 27,668 $ 60,954 $ 38,348 $ 18,528 $ 8,888 $ 7,892 $ 6,824 $ 169,102 Nonperforming 0 35 23 66 0 0 2 126 Total consumer direct $ 27,668 $ 60,989 $ 38,371 $ 18,594 $ 8,888 $ 7,892 $ 6,826 $ 169,228 Home equity: Performing $ 31,060 $ 53,585 $ 31,703 $ 26,694 $ 21,831 $ 40,438 $ 210,726 $ 416,037 Nonperforming 0 0 0 65 165 644 1,632 2,506 Total home equity $ 31,060 $ 53,585 $ 31,703 $ 26,759 $ 21,996 $ 41,082 $ 212,358 $ 418,543 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)	6 Months Ended
	Jun. 30, 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: June 30, 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 $ 69,403 $ (52,838 ) $ 16,565 $ 66,475 $ (50,057 ) $ 16,418 Other intangibles 90,462 (46,981 ) 43,481 89,266 (42,571 ) 46,695 Total amortizing intangibles $ 159,865 $ (99,819 ) $ 60,046 $ 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) Jul - Dec 2020 $ 7,106 2021 12,640 2022 10,844 2023 9,082 2024 7,551 Thereafter 12,823 Total $ 60,046
Components of Goodwill	Shown below are the components of the Company’s goodwill at December 31, 2019 and June 30, 2020: (000’s omitted) December 31, 2019 Activity June 30, 2020 Goodwill, net $ 773,810 $ 18,905 $ 792,715

MANDATORILY REDEEMABLE PREFER_2

MANDATORILY REDEEMABLE PREFERRED SECURITIES (Tables)	6 Months Ended
	Jun. 30, 2020
MANDATORILY REDEEMABLE PREFERRED SECURITIES [Abstract]
Terms of Preferred Securities	As of June 30, 2020, the Company sponsors business trusts, Community Capital Trust IV (“CCT IV”) and Steuben Statutory Trust II (“SST II”), of which of the common stock is owned by the Company. The common stock of Steuben Statutory Trust II was acquired in the Steuben acquisition. 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 June 30, 2020, the terms of the preferred securities of each trust are as follows: Trust Issuance Date Par Amount Interest Rate Maturity Date Call Price CCT IV 12/8/2006 $75.0 million 3 month LIBOR plus 1.65% (1.96%) 12/15/2036 Par SST II 07/16/2007 $2.0 million 3 month LIBOR plus 1.55% (1.86%) 09/15/2037 Par

BENEFIT PLANS (Tables)

BENEFIT PLANS (Tables)	6 Months Ended
	Jun. 30, 2020
BENEFIT PLANS [Abstract]
Net Periodic Benefit Cost	The net periodic benefit cost for the three and six months ended June 30, 2020 and 2019 is as follows: Pension Benefits Post-retirement Benefits Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (000’s omitted) 2020 2019 2020 2019 2020 2019 2020 2019 Service cost $ 1,438 $ 1,270 $ 2,875 $ 2,540 $ 0 $ 0 $ 0 $ 0 Interest cost 1,356 1,565 2,712 3,133 14 18 28 35 Expected return on plan assets (3,932 ) (3,578 ) (7,864 ) (7,155 ) 0 0 0 0 Amortization of unrecognized net loss 810 643 1,620 1,284 10 9 20 19 Amortization of prior service cost 60 16 120 31 (44 ) (45 ) (89 ) (89 ) Net periodic benefit $ (268 ) $ (84 ) $ (537 ) $ (167 ) $ (20 ) $ (18 ) $ (41 ) $ (35 )

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	6 Months Ended
	Jun. 30, 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 and six months ended June 30, 2020 and 2019: Three Months Ended Six Months Ended June 30, June 30, (000’s omitted, except per share data) 2020 2019 2020 2019 Net income $ 35,248 $ 45,015 $ 75,382 $ 86,961 Income attributable to unvested stock-based compensation awards (127 ) (146 ) (264 ) (255 ) Income available to common shareholders $ 35,121 $ 44,869 $ 75,118 $ 86,706 Weighted-average common shares outstanding – basic 52,487 51,659 52,262 51,590 Basic earnings per share $ 0.67 $ 0.87 $ 1.44 $ 1.68 Net income $ 35,248 $ 45,015 $ 75,382 $ 86,961 Income attributable to unvested stock-based compensation awards (127 ) (146 ) (264 ) (255 ) Income available to common shareholders $ 35,121 $ 44,869 $ 75,118 $ 86,706 Weighted-average common shares outstanding – basic 52,487 51,659 52,262 51,590 Assumed exercise of stock options 339 529 372 535 Weighted-average common shares outstanding – diluted 52,826 52,188 52,634 52,125 Diluted earnings per share $ 0.66 $ 0.86 $ 1.43 $ 1.66

COMMITMENTS, CONTINGENT LIABI_2

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS (Tables)	6 Months Ended
	Jun. 30, 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) June 30, 2020 December 31, 2019 Commitments to extend credit $ 1,142,557 $ 1,143,780 Standby letters of credit 39,466 37,872 Total $ 1,182,023 $ 1,181,652

FAIR VALUE (Tables)

FAIR VALUE (Tables)	6 Months Ended
	Jun. 30, 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. June 30, 2020 (000’s omitted) Level 1 Level 2 Level 3 Total Fair Value Available-for-sale investment securities: U.S. Treasury and agency securities $ 1,989,069 $ 183,234 $ 0 $ 2,172,303 Obligations of state and political subdivisions 0 521,705 0 521,705 Government agency mortgage-backed securities 0 535,078 0 535,078 Corporate debt securities 0 4,577 0 4,577 Government agency collateralized mortgage obligations 0 59,453 0 59,453 Total available-for-sale investment securities 1,989,069 1,304,047 0 3,293,116 Equity securities 433 0 0 433 Mortgage loans held for sale 0 5,517 0 5,517 Commitments to originate real estate loans for sale 0 0 859 859 Forward sales commitments 0 83 0 83 Interest rate swap agreements asset 0 1,882 0 1,882 Interest rate swap agreements liability 0 (1,289 ) 0 (1,289 ) Total $ 1,989,502 $ 1,310,240 $ 859 $ 3,300,601 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. June 30, 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 3,186 3,186 0 0 1,270 1,270 Mortgage servicing rights 0 0 122 122 0 0 56 56 Total $ 0 $ 0 $ 4,156 $ 4,156 $ 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 June 30, 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 3,186 Fair value of collateral Estimated cost of disposal/market adjustment 9.4% - 85.7% (26.5 %) Commitments to originate real estate loans for sale 859 Discounted cash flow Embedded servicing value 1.0 % Mortgage servicing rights 122 Discounted cash flow Weighted average constant prepayment rate 52.8 % Weighted average discount rate 1.93 % 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 June 30, 2020 and December 31, 2019 are as follows: June 30, 2020 December 31, 2019 (000’s omitted) Carrying Value Fair Value Carrying Value Fair Value Financial assets: Net loans $ 7,463,602 $ 7,801,009 $ 6,840,632 $ 7,028,663 Financial liabilities: Deposits 10,846,673 10,864,309 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 168,491 168,491 241,708 241,708 Other Federal Home Loan Bank borrowings 7,704 7,860 3,750 3,755 Subordinated notes payable 13,755 13,755 13,795 13,795 Subordinated debt held by unconsolidated subsidiary trusts 79,382 79,382 77,320 77,320

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	6 Months Ended
	Jun. 30, 2020
DERIVATIVE INSTRUMENTS [Abstract]
Amounts Related to Cumulative Basis Adjustments for Fair Value Hedges	As of June 30, 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 June 30, 2020 December 31, 2019 June 30, 2020 December 31, 2019 Loans $ 5,653 $ 6,390 $ (593) $ (265)
Fair Value of Derivative Instruments	Fair values of derivative instruments as of June 30, 2020 and December 31, 2019 are as follows: (000’s omitted) June 30, 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 $ 593 Derivatives not designated as hedging instruments under Subtopic 815-20 Interest rate swaps Other assets 1,289 Accrued interest and other liabilities $ 1,289 Commitments to originate real estate loans for sale Other assets 859 Forward sales commitments Other assets 83 Total derivatives $ 2,824 $ 1,289 (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)	6 Months Ended
	Jun. 30, 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 June 30, 2020 Net interest income $ 91,645 $ 246 $ 60 $ 0 $ 91,951 Provision for credit losses 9,774 0 0 0 9,774 Noninterest revenues 14,991 24,504 14,817 (1,374 ) 52,938 Amortization of intangible assets 1,364 1,411 749 0 3,524 Acquisition expenses 3,372 0 0 0 3,372 Other operating expenses 59,130 14,948 11,303 (1,374 ) 84,007 Income before income taxes $ 32,996 $ 8,391 $ 2,825 $ 0 $ 44,212 Assets $ 13,272,929 $ 216,122 $ 78,022 $ (122,856 ) $ 13,444,217 Goodwill $ 689,128 $ 83,275 $ 20,312 $ 0 $ 792,715 Core deposit intangibles & Other intangibles $ 16,565 $ 34,870 $ 8,611 $ 0 $ 60,046 Three Months Ended June 30, 2019 Net interest income $ 88,127 $ 131 $ 42 $ 0 $ 88,300 Provision for credit losses 1,400 0 0 0 1,400 Noninterest revenues 21,921 24,839 15,159 (1,213 ) 60,706 Amortization of intangible assets 1,375 1,669 860 0 3,904 Acquisition expenses 1,194 0 0 0 1,194 Other operating expenses 60,578 15,405 11,308 (1,213 ) 86,078 Income before income taxes $ 45,501 $ 7,896 $ 3,033 $ 0 $ 56,430 Assets $ 10,534,555 $ 206,178 $ 72,862 $ (68,207 ) $ 10,745,388 Goodwill $ 629,916 $ 83,275 $ 20,312 $ 0 $ 733,503 Core deposit intangibles & Other intangibles $ 15,738 $ 41,107 $ 10,167 $ 0 $ 67,012 (000’s omitted) Banking Employee Benefit Services All Other Eliminations Consolidated Total Six Months Ended June 30, 2020 Net interest income $ 181,409 $ 486 $ 110 $ 0 $ 182,005 Provision for credit losses 15,368 0 0 0 15,368 Noninterest revenues 33,672 50,429 30,352 (2,893 ) 111,560 Amortization of intangible assets 2,781 2,905 1,505 0 7,191 Acquisition expenses 3,741 0 0 0 3,741 Other operating expenses 123,330 30,079 23,118 (2,893 ) 173,634 Income before income taxes $ 69,861 $ 17,931 $ 5,839 $ 0 $ 93,631 Six Months Ended June 30, 2019 Net interest income $ 174,842 $ 239 $ 78 $ 0 $ 175,159 Provision for credit losses 3,822 0 0 0 3,822 Noninterest revenues 39,269 49,509 29,606 (1,982 ) 116,402 Amortization of intangible assets 2,858 3,438 1,738 0 8,034 Acquisition expenses 1,728 0 0 0 1,728 Other operating expenses 120,347 29,684 22,017 (1,982 ) 170,066 Income before income taxes $ 85,356 $ 16,626 $ 5,929 $ 0 $ 107,911

ACQUISITIONS (Details)

ACQUISITIONS (Details) shares in Thousands, $ in Thousands	Jun. 12, 2020USD ($)BranchCountyshares	Sep. 18, 2019USD ($)	Jul. 12, 2019USD ($)BranchCounty	Jan. 02, 2019USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)
Acquisitions [Abstract]
Cash		$ 500	$ 95,034
Loans acquired								$ 339,692
Investment securities			39,770
Increase in deposits								1,335,437	$ 165,834
Customer Lists [Member]
Acquisitions [Abstract]
Intangibles		$ 500
Steuben [Member]
Acquisitions [Abstract]
Issuance of common shares (in shares) | shares	1,360
Cash	$ 21,613
Assets acquired	610,100
Loans acquired	339,700
Investment securities	$ 180,497
Revenues					$ 600			600
Direct expenses					300			300
Steuben [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	11
Kinderhook Bank Corp [Member]
Acquisitions [Abstract]
Cash			$ 93,384
Number of branch locations | Branch			11
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					4,400			8,900
Direct expenses					$ 1,700			$ 3,600
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		Jun. 12, 2020	Sep. 18, 2019	Jul. 12, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Consideration paid [Abstract]
Cash			$ 500	$ 95,034
Community Bank System, Inc. common stock				0
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, net of allowance for credit losses on PCD loans	[1]			479,877
Premises and equipment, net				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	$ 792,715	$ 773,810	$ 733,503
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
Steuben [Member]
Consideration paid [Abstract]
Cash		$ 21,613
Community Bank System, Inc. common stock		76,942
Total net consideration paid		98,555
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents		55,973
Investment securities		180,497
Loans, net of allowance for credit losses on PCD loans	[1]	339,164
Premises and equipment, net		8,307
Accrued interest and fees receivable		2,712
Other assets		19,303
Deposits		(516,269)
Other liabilities		(6,436)
Other Federal Home Loan Bank borrowings		(6,000)
Subordinated notes payable		0
Subordinated debt held by unconsolidated subsidiary trusts		(2,062)
Total identifiable assets, net		79,313
Goodwill		19,242
Steuben [Member] | Core Deposit Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles		2,928
Steuben [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles		$ 1,196
Kinderhook Bank Corp [Member]
Consideration paid [Abstract]
Cash				93,384
Community Bank System, Inc. common stock				0
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, net of allowance for credit losses on PCD loans	[1]			479,877
Premises and equipment, net				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	[2]			1,650
Community Bank System, Inc. common stock	[2]			0
Total net consideration paid	[2]			1,650
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Cash and cash equivalents	[2]			0
Investment securities	[2]			0
Loans, net of allowance for credit losses on PCD loans	[1],[2]			0
Premises and equipment, net	[2]			0
Accrued interest and fees receivable	[2]			0
Other assets	[2]			0
Deposits	[2]			0
Other liabilities	[2]			0
Other Federal Home Loan Bank borrowings	[2]			0
Subordinated notes payable	[2]			0
Subordinated debt held by unconsolidated subsidiary trusts	[2]			0
Total identifiable assets, net	[2]			1,650
Goodwill	[2]			0
Other [Member] | Core Deposit Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles	[2]			0
Other [Member] | Other Intangibles [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed [Abstract]
Intangibles	[2]			$ 1,650
[1]	Acquisition-related allowance for credit losses on purchased credit deteriorated (“PCD”) loans applicable beginning in 2020.
[2]	Includes amounts related to both acquisitions completed by CISI in 2019.

ACQUISITIONS, Summary of Loans

ACQUISITIONS, Summary of Loans Acquired (Details) - USD ($) $ in Thousands	Jun. 12, 2020	Jul. 12, 2019
Kinderhook Bank Corp [Member]
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
Kinderhook Bank Corp [Member] | 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
Kinderhook Bank Corp [Member] | 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
Steuben [Member] | PCD Loans [Member]
Summary of loans acquired [Abstract]
Par value of loans at acquisition	$ 24,198
Allowance for credit losses at acquisition	(528)
Non-credit discount at acquisition	(80)
Fair value of acquired loans	23,590
Steuben [Member] | Non-PCD Loans [Member]
Summary of loans acquired [Abstract]
Contractually required principal and interest at acquisition	416,446
Contractual cash flows not expected to be collected	(3,177)
Expected cash flows at acquisition	413,269
Interest component of expected cash flows	(97,695)
Fair value of acquired loans	$ 315,574

ACQUISITIONS, Intangible Asset,

ACQUISITIONS, Intangible Asset, Goodwill and Acquisition-related Expenses (Details) - USD ($) $ in Thousands	Jul. 12, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Fair Value of Subordinated Notes Payable [Abstract]
Subordinated notes payable		$ 13,755		$ 13,755		$ 13,795
Summary of loans acquired [Abstract]
Acquisition-related expenses		3,372	$ 1,194	$ 3,741	$ 1,728
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
Steuben [Member]
Summary of loans acquired [Abstract]
Acquisition-related expenses		$ 3,300		$ 3,600
Steuben [Member] | Core Deposits [Member]
Intangible Assets [Abstract]
Estimated useful life				8 years
Steuben [Member] | Other Intangibles [Member]
Intangible Assets [Abstract]
Estimated useful life				8 years

ACQUISITIONS, Supplemental Pro

ACQUISITIONS, Supplemental Pro Forma Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Supplemental Pro Forma Financial Information [Abstract]
Acquisition-related expenses	$ 3,372	$ 1,194	$ 3,741	$ 1,728
Steuben [Member]
Supplemental Pro Forma Financial Information [Abstract]
Acquisition-related expenses	3,300		3,600
Total revenue, net of interest expense, pro forma	149,576	154,878	304,088	303,152
Net income, pro forma	$ 39,072	$ 46,447	$ 80,848	$ 86,774

ACCOUNTING POLICIES (Details)

ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2020
Allowance for Credit Losses - Debt Securities [Abstract]
Accrued interest receivable on available-for-sale debt securities		$ 11,400
Loans [Abstract]
Accrued interest receivable on loans		$ 23,700
Number of days past due for loans to be placed on nonaccrual status		90 days
Contract Balances [Abstract]
Accounts receivable	$ 26,800	$ 25,300
Unbilled fee revenue	7,500	7,600
Unearned revenue	1,800	1,600
New Accounting Pronouncements [Abstract]
Retained earnings	882,851	$ 915,392
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] | 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
Addition to allowance for credit losses	$ 3,100

INVESTMENT SECURITIES, Availabl

INVESTMENT SECURITIES, Available-for-Sale Portfolio (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Available-for-Sale Portfolio [Abstract]
Amortized cost	$ 3,129,978	$ 3,011,551
Gross unrealized gains	163,430	42,017
Gross unrealized losses	292	9,140
Fair value	3,293,116	3,044,428
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	3,129,978
Fair value	3,293,116
U.S. Treasury and Agency Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	2,048,199	2,030,060
Gross unrealized gains	124,122	21,674
Gross unrealized losses	18	7,975
Fair value	2,172,303	2,043,759
Obligations of State and Political Subdivisions [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	499,961	497,852
Gross unrealized gains	21,764	14,382
Gross unrealized losses	20	26
Fair value	521,705	512,208
Government Agency Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	519,370	428,491
Gross unrealized gains	15,956	5,478
Gross unrealized losses	248	1,107
Fair value	535,078	432,862
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	4,509	2,527
Gross unrealized gains	68	1
Gross unrealized losses	0	0
Fair value	4,577	2,528
Government Agency Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized cost	57,939	52,621
Gross unrealized gains	1,520	482
Gross unrealized losses	6	32
Fair value	$ 59,453	$ 53,071

INVESTMENT SECURITIES, Equity a

INVESTMENT SECURITIES, Equity and Other Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Equity and Other Securities [Abstract]
Amortized cost	$ 43,411	$ 42,965
Gross unrealized gains	954	950
Gross unrealized losses	22	0
Equity and other securities (cost of $42,965 and $44,678, respectively)	44,343	43,915
Equity Securities, at Fair Value [Abstract]
Amortized cost	251	251
Gross unrealized gains	204	200
Gross unrealized losses	22	0
Fair value	433	451
Federal Home Loan Bank Common Stock [Member]
Other Equity Securities, at Adjusted Cost [Abstract]
Amortized cost	7,576	7,246
Fair value	7,576	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	4,662	4,546
Gross unrealized gains	750	750
Fair value	$ 5,412	$ 5,296

INVESTMENT SECURITIES, Investme

INVESTMENT SECURITIES, Investment Securities in a Continuous Unrealized Loss Position (Details)	Jun. 30, 2020USD ($)Position	Dec. 31, 2019USD ($)Position
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	219	88
12 months or longer | Position	3	62
Total | Position	222	150
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 124,839,000	$ 710,602,000
12 months or longer	15,000	83,378,000
Total	124,854,000	793,980,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	292,000	8,351,000
12 months or longer	0	789,000
Total	$ 292,000	$ 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	$ 79,000
12 months or longer	0
Total	79,000
Equity and Other Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	22,000
12 months or longer	0
Total	22,000
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	8	12
12 months or longer | Position	0	5
Total | Position	8	17
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 12,058,000	$ 592,678,000
12 months or longer	0	25,998,000
Total	12,058,000	618,676,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	18,000	7,970,000
12 months or longer	0	5,000
Total	$ 18,000	$ 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	52	21
12 months or longer | Position	0	0
Total | Position	52	21
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 20,145,000	$ 22,716,000
12 months or longer	0	0
Total	20,145,000	22,716,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	20,000	26,000
12 months or longer	0	0
Total	$ 20,000	$ 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	142	50
12 months or longer | Position	2	52
Total | Position	144	102
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 87,290,000	$ 89,237,000
12 months or longer	15,000	52,975,000
Total	87,305,000	142,212,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	248,000	341,000
12 months or longer	0	766,000
Total	$ 248,000	$ 1,107,000
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-Sale Portfolio in Unrealized Loss Positions, Number of Positions [Abstract]
Less than 12 months | Position	17	5
12 months or longer | Position	1	5
Total | Position	18	10
Available-for-Sale Securities, in Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 5,346,000	$ 5,971,000
12 months or longer	0	4,405,000
Total	5,346,000	10,376,000
Available-for-Sale Portfolio, Debt Maturities, Gross Unrealized Losses [Abstract]
Less than 12 months	6,000	14,000
12 months or longer	0	18,000
Total	$ 6,000	$ 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	$ 79,000
12 months or longer	0
Total	79,000
Equity and Other Securities, Continuous Unrealized Loss Position, Gross Unrealized Losses [Abstract]
Less than 12 months	22,000
12 months or longer	0
Total	$ 22,000

INVESTMENT SECURITIES, Amortize

INVESTMENT SECURITIES, Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Due in one year or less	$ 663,860
Due after one through five years	925,191
Due after five years through ten years	466,983
Due after ten years	496,635
Subtotal	2,552,669
Amortized cost	3,129,978
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Due in one year or less	670,059
Due after one through five years	971,561
Due after five years through ten years	509,723
Due after ten years	547,242
Subtotal	2,698,585
Fair value	3,293,116
Government Agency Mortgage-Backed Securities [Member]
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	519,370
Amortized cost	519,370	$ 428,491
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Without single maturity date	535,078
Fair value	535,078	432,862
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-Sale, Debt Maturities, Amortized Cost [Abstract]
Without single maturity date	57,939
Amortized cost	57,939	52,621
Available-for-Sale, Debt Maturities, Fair Value [Abstract]
Without single maturity date	59,453
Fair value	$ 59,453	$ 53,071

INVESTMENT SECURITIES, Invest_2

INVESTMENT SECURITIES, Investment Securities Pledged as Collateral (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Investment Securities Pledged as Collateral [Abstract]
Proceeds from sales of securities		$ 0	$ 590,179
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		$ 177,400
Proceeds from sales of securities	$ 590,200		590,200
Gross realized gains	5,000		5,000
Gross realized losses	$ 100		$ 100

LOANS, Loan Summary (Details)

LOANS, Loan Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 7,528,039		$ 6,890,543
Allowance for credit losses	(64,437)	$ (55,652)	(49,911)	$ (49,310)	$ (49,107)	$ (49,284)
Net loans	7,463,602		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	3,455,343		2,775,876
Allowance for credit losses	(24,204)	(19,489)	(19,426)	(17,769)	(18,271)	(18,522)
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	2,428,060		2,430,902
Allowance for credit losses	(13,088)	(12,430)	(10,269)	(10,763)	(10,317)	(10,124)
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	1,056,865		1,113,062
Allowance for credit losses	(15,866)	(13,694)	(13,712)	(14,345)	(14,251)	(14,366)
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	169,228		184,378
Allowance for credit losses	(4,028)	(3,737)	(3,255)	(3,184)	(3,056)	(3,095)
Consumer Portfolio Segment [Member] | Home Equity [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	418,543		386,325
Allowance for credit losses	$ (2,690)	$ (2,484)	$ (2,129)	$ (2,103)	$ (2,067)	$ (2,144)

LOANS, Credit Quality By Past D

LOANS, Credit Quality By Past Due Status (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
		Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		$ 6,063	$ 6,063
Nonaccrual		20,697	20,697
Total past due		54,347	54,347
Current		7,473,692	7,473,692
Total loans		7,528,039	7,528,039	$ 6,890,543
Interest income on nonaccrual loans		0	0
Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		27,587	27,587
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	[1]			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		1,186	1,186
Nonaccrual		5,001	5,001
Total past due		8,682	8,682
Current		3,446,661	3,446,661
Total loans		3,455,343	3,455,343	2,775,876
Commercial Portfolio Segment [Member] | Business Lending [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		2,495	2,495
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	[1]			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		3,651	3,651
Nonaccrual		13,544	13,544
Total past due		30,734	30,734
Current		2,397,326	2,397,326
Total loans		2,428,060	2,428,060	2,430,902
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		13,539	13,539
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	[1]			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		744	744
Nonaccrual		2	2
Total past due		8,862	8,862
Current		1,048,003	1,048,003
Total loans		1,056,865	1,056,865	1,113,062
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		8,116	8,116
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	[1]			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		72	72
Nonaccrual		54	54
Total past due		1,001	1,001
Current		168,227	168,227
Total loans		169,228	169,228	184,378
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		875	875
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	[1]			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		410	410
Nonaccrual		2,096	2,096
Total past due		5,068	5,068
Current		413,475	413,475
Total loans		418,543	418,543	386,325
Consumer Portfolio Segment [Member] | Home Equity [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		$ 2,562	$ 2,562
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	[1]			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]	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	Jun. 30, 2020	Dec. 31, 2019
Term Loans Amortized Cost Basis by Origination Year [Abstract]
Loans	$ 7,528,039	$ 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	670,379
2019	405,722
2018	395,076
2017	294,450
2016	308,151
Prior	746,224
Revolving loans amortized cost basis	635,341
Total	3,455,343
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	661,019
2019	390,621
2018	371,073
2017	273,598
2016	274,860
Prior	634,379
Revolving loans amortized cost basis	567,034
Total	3,172,584
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	6,026
2019	12,045
2018	6,641
2017	12,701
2016	18,005
Prior	56,168
Revolving loans amortized cost basis	30,485
Total	142,071
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	3,334
2019	3,056
2018	17,362
2017	8,151
2016	15,286
Prior	55,677
Revolving loans amortized cost basis	37,822
Total	140,688
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	158,861
2019	356,457
2018	273,486
2017	269,787
2016	271,965
Prior	1,087,278
Revolving loans amortized cost basis	10,226
Total	2,428,060
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	111,491
2019	247,801
2018	186,837
2017	185,472
2016	178,776
Prior	715,498
Revolving loans amortized cost basis	454
Total	1,626,329
Consumer Mortgage [Member] | FICO AB [Member] | Performing [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	111,491
2019	247,646
2018	186,686
2017	185,064
2016	178,459
Prior	712,049
Revolving loans amortized cost basis	454
Total	1,621,849
Consumer Mortgage [Member] | FICO AB [Member] | Nonperforming [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	155
2018	151
2017	408
2016	317
Prior	3,449
Revolving loans amortized cost basis	0
Total	4,480
Consumer Mortgage [Member] | FICO CDE [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	47,370
2019	108,656
2018	86,649
2017	84,315
2016	93,189
Prior	371,780
Revolving loans amortized cost basis	9,772
Total	801,731
Consumer Mortgage [Member] | FICO CDE [Member] | Performing [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	47,370
2019	108,296
2018	85,917
2017	83,641
2016	91,733
Prior	362,287
Revolving loans amortized cost basis	9,772
Total	789,016
Consumer Mortgage [Member] | FICO CDE [Member] | Nonperforming [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	0
2019	360
2018	732
2017	674
2016	1,456
Prior	9,493
Revolving loans amortized cost basis	0
Total	12,715
Consumer Indirect [Member]
Term Loans Amortized Cost Basis by Origination Year [Abstract]
2020	135,342
2019	372,460
2018	260,805
2017	118,294
2016	88,691
Prior	81,273
Revolving loans amortized cost basis	0
Total	1,056,865
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	135,333
2019	372,290
2018	260,629
2017	118,119
2016	88,554
Prior	81,194
Revolving loans amortized cost basis	0
Total	1,056,119
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	9
2019	170
2018	176
2017	175
2016	137
Prior	79
Revolving loans amortized cost basis	0
Total	746
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	27,668
2019	60,989
2018	38,371
2017	18,594
2016	8,888
Prior	7,892
Revolving loans amortized cost basis	6,826
Total	169,228
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	27,668
2019	60,954
2018	38,348
2017	18,528
2016	8,888
Prior	7,892
Revolving loans amortized cost basis	6,824
Total	169,102
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	35
2018	23
2017	66
2016	0
Prior	0
Revolving loans amortized cost basis	2
Total	126
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	31,060
2019	53,585
2018	31,703
2017	26,759
2016	21,996
Prior	41,082
Revolving loans amortized cost basis	212,358
Total	418,543
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	31,060
2019	53,585
2018	31,703
2017	26,694
2016	21,831
Prior	40,438
Revolving loans amortized cost basis	210,726
Total	416,037
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	65
2016	165
Prior	644
Revolving loans amortized cost basis	1,632
Total	$ 2,506
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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Impaired loans [Abstract]
Loans with allowance allocation	$ 0		$ 0		$ 0
Loans without allowance allocation	1,414		1,414		1,414
Carrying balance	1,414		1,414		1,414
Contractual balance	2,943		2,943		2,944
Specifically allocated allowance	0		0		$ 0
Average carrying balance of individually evaluated impaired loans	1,400	$ 5,100	1,800	$ 5,600
Interest income on individually evaluated impaired loans	$ 0	$ 0	$ 0	$ 0

LOANS, Troubled Debt Restructur

LOANS, Troubled Debt Restructurings (TDRs) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)Loan	Jun. 30, 2019USD ($)Loan	Jun. 30, 2020USD ($)Loan	Jun. 30, 2019USD ($)Loan	Dec. 31, 2019USD ($)Loan
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	239		239		248
TDRs, amount	$ 7,030,000		$ 7,030,000		$ 6,982,000
Loans modified in TDR during the year, number | Loan	7	15	25	32
Loans modified in TDR during the year, amount	$ 249,000	$ 643,000	$ 928,000	$ 1,296,000
Maximum [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
Threshold balance of TDR loans collectively included in general loan loss allocation and qualitative review	$ 500,000		$ 500,000
Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	77		77		80
TDRs, amount	$ 3,378,000		$ 3,378,000		$ 3,609,000
Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	162		162		168
TDRs, amount	$ 3,652,000		$ 3,652,000		$ 3,373,000
Commercial Portfolio Segment [Member] | Minimum [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
Threshold balance of loans individually evaluated for impairment	$ 500,000		$ 500,000
Commercial Portfolio Segment [Member] | Business Lending [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	11		11		11
TDRs, amount	$ 797,000		$ 797,000		$ 882,000
Loans modified in TDR during the year, number | Loan	0	2	0	2
Loans modified in TDR during the year, amount	$ 0	$ 250,000	$ 0	$ 250,000
Commercial Portfolio Segment [Member] | Business Lending [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	8		8		8
TDRs, amount	$ 602,000		$ 602,000		$ 681,000
Commercial Portfolio Segment [Member] | Business Lending [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	3		3		3
TDRs, amount	$ 195,000		$ 195,000		$ 201,000
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	105		105		106
TDRs, amount	$ 4,721,000		$ 4,721,000		$ 4,530,000
Loans modified in TDR during the year, number | Loan	3	4	9	11
Loans modified in TDR during the year, amount	$ 174,000	$ 283,000	$ 738,000	$ 861,000
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	58		58		59
TDRs, amount	$ 2,491,000		$ 2,491,000		$ 2,638,000
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	47		47		47
TDRs, amount	$ 2,230,000		$ 2,230,000		$ 1,892,000
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	79		79		84
TDRs, amount	$ 878,000		$ 878,000		$ 941,000
Loans modified in TDR during the year, number | Loan	3	4	14	12
Loans modified in TDR during the year, amount	$ 47,000	$ 33,000	$ 151,000	$ 98,000
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	0		0		0
TDRs, amount	$ 0		$ 0		$ 0
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	79		79		84
TDRs, amount	$ 878,000		$ 878,000		$ 941,000
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	23		23		23
TDRs, amount	$ 99,000		$ 99,000		$ 101,000
Loans modified in TDR during the year, number | Loan	0	2	1	3
Loans modified in TDR during the year, amount	$ 0	$ 6,000	$ 11,000	$ 12,000
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	0		0		0
TDRs, amount	$ 0		$ 0		$ 0
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	23		23		23
TDRs, amount	$ 99,000		$ 99,000		$ 101,000
Consumer Portfolio Segment [Member] | Home Equity [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	21		21		24
TDRs, amount	$ 535,000		$ 535,000		$ 528,000
Loans modified in TDR during the year, number | Loan	1	3	1	4
Loans modified in TDR during the year, amount	$ 28,000	$ 71,000	$ 28,000	$ 75,000
Consumer Portfolio Segment [Member] | Home Equity [Member] | Nonaccrual [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	11		11		13
TDRs, amount	$ 285,000		$ 285,000		$ 290,000
Consumer Portfolio Segment [Member] | Home Equity [Member] | Accruing [Member]
Troubled Debt Restructurings (TDRs) [Abstract]
TDRs, number | Loan	10		10		11
TDRs, amount	$ 250,000		$ 250,000		$ 238,000

LOANS, Allowance for Credit Los

LOANS, Allowance for Credit Losses (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 30, 2021	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)
Allowance for credit losses - loans [Roll Forward]
Beginning balance		$ 55,652	$ 49,107	$ 49,911	$ 49,284
Charge-offs		(2,094)	(2,871)		(6,772)
Recoveries		1,184	1,674		2,976
Steuben acquisition		3,662
Provision		6,033	1,400		3,822
Ending balance		64,437	49,310	64,437	49,310
Liabilities for off-balance-sheet credit exposures [Roll Forward]
Beginning balance		845		0
Charge-offs		0
Recoveries		0
Steuben acquisition		67
Provision		540
Ending balance		1,452		1,452
Total allowance for credit losses [Roll Forward]
Beginning balance		56,497		49,911
Charge-offs		(2,094)
Recoveries		1,184
Steuben acquisition		3,729
Provision		6,573
Ending balance		$ 65,889		$ 65,889
Allowance for Credit Losses [Abstract]
Allowance for credit losses to total loans ratio		0.0086		0.0086
Increase in allowance for credit losses to total loans ratio over the same quarter in prior year				800.00%
Increase in allowance for credit losses to total loans ratio over the prior year end				0.14%
Forecast [Member] | Minimum [Member] | COVID-19 [Member]
Allowance for Credit Losses [Abstract]
Percentage of peak unemployment	9.00%
Forecast [Member] | Maximum [Member] | COVID-19 [Member]
Allowance for Credit Losses [Abstract]
Percentage of peak unemployment	12.00%
Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				$ 51,268
Charge-offs				(5,141)
Recoveries				2,681
Steuben acquisition				3,662
Provision				11,967
Ending balance		$ 64,437		64,437
Liabilities for off-balance-sheet credit exposures [Roll Forward]
Beginning balance				1,185
Charge-offs				0
Recoveries				0
Steuben acquisition				67
Provision				200
Ending balance		1,452		1,452
Total allowance for credit losses [Roll Forward]
Beginning balance				52,453
Charge-offs				(5,141)
Recoveries				2,681
Steuben acquisition				3,729
Provision				12,167
Ending balance		65,889		65,889
Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [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			155	163	33
Charge-offs			0		0
Recoveries			0		0
Provision			0		122
Ending balance			155		155
Purchased Credit Impaired [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				0
Charge-offs				0
Recoveries				0
Steuben acquisition				0
Provision				0
Ending balance		0		0
Purchased Credit Impaired [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				(163)
Purchased Credit Deteriorated [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance		3,046		0
Charge-offs		0
Recoveries		48
Steuben acquisition		528
Provision		(61)
Ending balance		3,561		3,561
Purchased Credit Deteriorated [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				3,072
Charge-offs				0
Recoveries				48
Steuben acquisition				528
Provision				(87)
Ending balance		3,561		3,561
Purchased Credit Deteriorated [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [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		19,489	18,271	19,426	18,522
Charge-offs		(7)	(253)		(1,469)
Recoveries		84	169		303
Steuben acquisition		2,483
Provision		2,155	(418)		413
Ending balance		24,204	17,769	24,204	17,769
Commercial Portfolio Segment [Member] | Business Lending [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				19,714
Charge-offs				(183)
Recoveries				222
Steuben acquisition				2,483
Provision				1,968
Ending balance		24,204		24,204
Commercial Portfolio Segment [Member] | Business Lending [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [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		12,430	10,317	10,269	10,124
Charge-offs		(234)	(587)		(840)
Recoveries		36	14		36
Steuben acquisition		146
Provision		710	1,019		1,443
Ending balance		13,088	10,763	13,088	10,763
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				9,218
Charge-offs				(420)
Recoveries				44
Steuben acquisition				146
Provision				4,100
Ending balance		13,088		13,088
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [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		13,694	14,251	13,712	14,366
Charge-offs		(1,431)	(1,482)		(3,305)
Recoveries		833	1,239		2,201
Steuben acquisition		183
Provision		2,587	337		1,083
Ending balance		15,866	14,345	15,866	14,345
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				12,715
Charge-offs				(3,510)
Recoveries				1,996
Steuben acquisition				183
Provision				4,482
Ending balance		15,866		15,866
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [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		3,737	3,056	3,255	3,095
Charge-offs		(341)	(445)		(980)
Recoveries		171	221		400
Steuben acquisition		87
Provision		374	352		669
Ending balance		4,028	3,184	4,028	3,184
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				2,612
Charge-offs				(874)
Recoveries				353
Steuben acquisition				87
Provision				1,850
Ending balance		4,028		4,028
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [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		2,484	2,067	2,129	2,144
Charge-offs		(81)	(104)		(178)
Recoveries		12	31		36
Steuben acquisition		235
Provision		40	109		101
Ending balance		2,690	2,103	2,690	2,103
Consumer Portfolio Segment [Member] | Home Equity [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				2,937
Charge-offs				(154)
Recoveries				18
Steuben acquisition				235
Provision				(346)
Ending balance		2,690		2,690
Consumer Portfolio Segment [Member] | Home Equity [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				808
Unallocated Financing Receivables [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance		772	990	957	1,000
Charge-offs		0	0		0
Recoveries		0	0		0
Steuben acquisition		0
Provision		228	1		(9)
Ending balance		1,000	$ 991	1,000	$ 991
Unallocated Financing Receivables [Member] | Topic ASC 326 [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				1,000
Charge-offs				0
Recoveries				0
Steuben acquisition				0
Provision				0
Ending balance		$ 1,000		1,000
Unallocated Financing Receivables [Member] | Topic ASC 326 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Allowance for credit losses - loans [Roll Forward]
Beginning balance				$ 43

LOANS, Carrying Amounts of Loan

LOANS, Carrying Amounts of Loans Purchased and Sold (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)
Carrying Amounts of Loans Purchased and Sold [Abstract]
Purchases	$ 339,692
Sales	15,599
Commercial Portfolio Segment [Member] | Business Lending [Member]
Carrying Amounts of Loans Purchased and Sold [Abstract]
Purchases	253,469
Sales	0
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Carrying Amounts of Loans Purchased and Sold [Abstract]
Purchases	26,733
Sales	15,599
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Carrying Amounts of Loans Purchased and Sold [Abstract]
Purchases	13,926
Sales	0
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Carrying Amounts of Loans Purchased and Sold [Abstract]
Purchases	6,022
Sales	0
Consumer Portfolio Segment [Member] | Home Equity [Member]
Carrying Amounts of Loans Purchased and Sold [Abstract]
Purchases	39,542
Sales	$ 0

GOODWILL AND IDENTIFIABLE INT_3

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Identifiable Intangible Assets [Abstract]
Gross carrying amount	$ 159,865	$ 155,741
Accumulated amortization	(99,819)	(92,628)
Net carrying amount	60,046	63,113
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Jul - Dec 2020	7,106
2021	12,640
2022	10,844
2023	9,082
2024	7,551
Thereafter	12,823
Net carrying amount	60,046	63,113
Components of goodwill [Abstract]
Goodwill, net, beginning of period	773,810
Goodwill, net, activity	18,905
Goodwill, net, end of period	792,715
Core Deposit Intangibles [Member]
Identifiable Intangible Assets [Abstract]
Gross carrying amount	69,403	66,475
Accumulated amortization	(52,838)	(50,057)
Net carrying amount	16,565	16,418
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Net carrying amount	16,565	16,418
Other Intangibles [Member]
Identifiable Intangible Assets [Abstract]
Gross carrying amount	90,462	89,266
Accumulated amortization	(46,981)	(42,571)
Net carrying amount	43,481	46,695
Estimated aggregate amortization expense for each of five succeeding fiscal years [Abstract]
Net carrying amount	$ 43,481	$ 46,695

MANDATORILY REDEEMABLE PREFER_3

MANDATORILY REDEEMABLE PREFERRED SECURITIES (Details) $ in Millions	Sep. 16, 2019USD ($)	Jun. 30, 2020USD ($)Trust
Mandatorily Redeemable Preferred Securities [Abstract]
Number of unconsolidated subsidiary business trusts owned | Trust		2
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		1.96%
Maturity date		Dec. 15, 2036
Call price		Par
Preferred Debt [Member] | Community Capital Trust IV [Member] | LIBOR [Member]
Terms of preferred securities for each trust [Abstract]
Term of variable rate		3 months
Variable interest rate, basis spread		1.65%
Preferred Debt [Member] | Steuben Statutory Trust II [Member]
Terms of preferred securities for each trust [Abstract]
Issuance date		Jul. 16, 2007
Par amount		$ 2
Effective interest rate		1.86%
Maturity date		Sep. 15, 2037
Call price		Par
Preferred Debt [Member] | Steuben Statutory Trust II [Member] | LIBOR [Member]
Terms of preferred securities for each trust [Abstract]
Term of variable rate		3 months
Variable interest rate, basis spread		1.55%

BENEFIT PLANS (Details)

BENEFIT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	$ 1,438	$ 1,270		$ 2,875	$ 2,540
Interest cost	1,356	1,565		2,712	3,133
Expected return on plan assets	(3,932)	(3,578)		(7,864)	(7,155)
Amortization of unrecognized net loss	810	643		1,620	1,284
Amortization of prior service cost	60	16		120	31
Net periodic benefit	(268)	(84)		(537)	(167)
Pension Benefits [Member] | Nonqualified Plan [Member] | Unfunded Plan [Member]
Pension Plans [Abstract]
Contribution made to defined benefit pension plan by employer	3,900		$ 7,300
Post-retirement Benefits [Member]
Net periodic benefit cost [Abstract]
Service cost	0	0		0	0
Interest cost	14	18		28	35
Expected return on plan assets	0	0		0	0
Amortization of unrecognized net loss	10	9		20	19
Amortization of prior service cost	(44)	(45)		(89)	(89)
Net periodic benefit	$ (20)	$ (18)		$ (41)	$ (35)

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
EARNINGS PER SHARE [Abstract]
Weighted-average anti-dilutive stock options outstanding (in shares)	600,000	500,000	600,000	500,000
Basic earnings per share [Abstract]
Net income	$ 35,248	$ 45,015	$ 75,382	$ 86,961
Income attributable to unvested stock-based compensation awards	(127)	(146)	(264)	(255)
Income available to common shareholders	$ 35,121	$ 44,869	$ 75,118	$ 86,706
Weighted-average common shares outstanding - basic (in shares)	52,487,000	51,659,000	52,262,000	51,590,000
Basic earnings per share (in dollars per share)	$ 0.67	$ 0.87	$ 1.44	$ 1.68
Diluted earnings per share [Abstract]
Net income	$ 35,248	$ 45,015	$ 75,382	$ 86,961
Income attributable to unvested stock-based compensation awards	(127)	(146)	(264)	(255)
Income available to common shareholders	$ 35,121	$ 44,869	$ 75,118	$ 86,706
Weighted-average common shares outstanding - basic (in shares)	52,487,000	51,659,000	52,262,000	51,590,000
Assumed exercise of stock options (in shares)	339,000	529,000	372,000	535,000
Weighted-average common shares outstanding - diluted (in shares)	52,826,000	52,188,000	52,634,000	52,125,000
Diluted earnings per share (in dollars per share)	$ 0.66	$ 0.86	$ 1.43	$ 1.66
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	Jun. 30, 2020	Dec. 31, 2019
Commitments, Contingent Liabilities and Restrictions [Abstract]
Contract amount of commitments and contingencies	$ 1,182,023	$ 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	1,142,557	1,143,780
Standby Letters of Credit [Member]
Commitments, Contingent Liabilities and Restrictions [Abstract]
Contract amount of commitments and contingencies	$ 39,466	$ 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	Jun. 30, 2020	Dec. 31, 2019
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	$ 3,293,116
Equity securities	433	$ 451
Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	859
U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,172,303	2,043,759
Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	521,705	512,208
Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	535,078	432,862
Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	4,577	2,528
Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	59,453	53,071
Recurring [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	3,293,116	3,044,428
Equity securities	433	451
Mortgage loans held for sale	5,517
Total	3,300,601	3,045,144
Recurring [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	859
Recurring [Member] | Forward Sales Commitments [Member]
Available-for-sale investment securities [Abstract]
Derivative liability	83
Recurring [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	1,882	851
Derivative liability	(1,289)	(586)
Recurring [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	2,172,303	2,043,759
Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	521,705	512,208
Recurring [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	535,078	432,862
Recurring [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	4,577	2,528
Recurring [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	59,453	53,071
Recurring [Member] | Level 1 [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	1,989,069	1,878,705
Equity securities	433	451
Mortgage loans held for sale	0
Total	1,989,502	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	1,989,069	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	1,304,047	1,165,723
Equity securities	0	0
Mortgage loans held for sale	5,517
Total	1,310,240	1,165,988
Mortgage loans held for sale, at principal value	4,300	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	83
Recurring [Member] | Level 2 [Member] | Interest Rate Swap Agreements [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	1,882	851
Derivative liability	(1,289)	(586)
Recurring [Member] | Level 2 [Member] | U.S. Treasury and Agency Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	183,234	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	521,705	512,208
Recurring [Member] | Level 2 [Member] | Government Agency Mortgage-Backed Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	535,078	432,862
Recurring [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	4,577	2,528
Recurring [Member] | Level 2 [Member] | Government Agency Collateralized Mortgage Obligations [Member]
Available-for-sale investment securities [Abstract]
Available-for-sale investment securities	59,453	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	859	0
Recurring [Member] | Level 3 [Member] | Commitments to Originate Real Estate Loans for Sale [Member]
Available-for-sale investment securities [Abstract]
Derivative asset	859
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	Jun. 30, 2020	Dec. 31, 2019
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	$ 848	$ 848
Other real estate owned	3,186	1,270
Mortgage servicing rights	122	56
Valuation allowance	0	0
Mortgage Servicing Rights [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Valuation allowance	400	300
Non-recurring [Member]
Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impaired loans	848	848
Other real estate owned	3,186	1,270
Mortgage servicing rights	122	56
Total	4,156	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	3,186	1,270
Mortgage servicing rights	122	56
Total	$ 4,156	$ 2,174

FAIR VALUE, Significant Unobser

FAIR VALUE, Significant Unobservable Inputs (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 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	$ 3,186	$ 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	$ 122	$ 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	0.528	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	0.0193	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	0.094	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	0.265	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	$ 859
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	0.010

FAIR VALUE, Carrying Amounts an

FAIR VALUE, Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Carrying Value [Member]
Financial assets [Abstract]
Net loans	$ 7,463,602	$ 6,840,632
Financial liabilities [Abstract]
Deposits	10,846,673	8,994,967
Overnight Federal Home Loan Bank borrowings	0	8,300
Securities sold under agreement to repurchase, short-term	168,491	241,708
Other Federal Home Loan Bank borrowings	7,704	3,750
Subordinated notes payable	13,755	13,795
Subordinated debt held by unconsolidated subsidiary trusts	79,382	77,320
Fair Value [Member]
Financial assets [Abstract]
Net loans	7,801,009	7,028,663
Financial liabilities [Abstract]
Deposits	10,864,309	8,997,551
Overnight Federal Home Loan Bank borrowings	0	8,300
Securities sold under agreement to repurchase, short-term	168,491	241,708
Other Federal Home Loan Bank borrowings	7,860	3,755
Subordinated notes payable	13,755	13,795
Subordinated debt held by unconsolidated subsidiary trusts	$ 79,382	$ 77,320

DERIVATIVE INSTRUMENTS (Details

DERIVATIVE INSTRUMENTS (Details) - Interest Rate Swaps [Member] - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Derivative Instruments [Abstract]
Derivative, notional amount	$ 15.6	$ 16.4
Derivative weighted average receive rate	2.14%	3.72%
Derivative weighted average pay rate	4.40%	4.39%
Weighted average maturity period	5 years 7 months 6 days	6 years 1 month 6 days
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative Instruments [Abstract]
Derivative, notional amount	$ 5.8	$ 6.2
Derivative weighted average receive rate	1.45%	2.47%
Derivative weighted average pay rate	3.11%	3.11%
Weighted average maturity period	13 years	13 years 6 months

DERIVATIVE INSTRUMENTS, Cumulat

DERIVATIVE INSTRUMENTS, Cumulative Basis Adjustments for Fair Value Hedges (Details) - Loans [Member] - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Cumulative Basis Adjustments for Fair Value Hedges [Abstract]
Carrying amount of the hedged assets	$ 5,653	$ 6,390
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets	$ (593)	$ (265)

DERIVATIVE INSTRUMENTS, Fair Va

DERIVATIVE INSTRUMENTS, Fair Values of Derivative Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Values of Derivative Instruments [Abstract]
Derivative assets	$ 2,824	$ 851
Derivative liabilities	1,289	586
Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative assets	593	265
Interest Rate Swaps [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative assets	1,289	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	1,289	$ 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	859
Forward Sales Commitments [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member]
Fair Values of Derivative Instruments [Abstract]
Derivative assets	$ 83

SEGMENT INFORMATION (Details)

SEGMENT INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Jul. 12, 2019
Information about reportable segments [Abstract]
Net interest income	$ 91,951	$ 88,300	$ 182,005	$ 175,159
Provision for credit losses	9,774	1,400	15,368	3,822
Noninterest revenues	52,938	60,706	111,560	116,402
Amortization of intangible assets	3,524	3,904	7,191	8,034
Acquisition expenses	3,372	1,194	3,741	1,728
Other operating expenses	84,007	86,078	173,634	170,066
Income before income taxes	44,212	56,430	93,631	107,911
Assets	13,444,217	10,745,388	13,444,217	10,745,388	$ 11,410,295
Goodwill	792,715	733,503	792,715	733,503	$ 773,810	$ 39,970
Core deposit intangibles & Other intangibles	60,046	67,012	60,046	67,012
Eliminations [Member]
Information about reportable segments [Abstract]
Net interest income	0	0	0	0
Provision for credit losses	0	0	0	0
Noninterest revenues	(1,374)	(1,213)	(2,893)	(1,982)
Amortization of intangible assets	0	0	0	0
Acquisition expenses	0	0	0	0
Other operating expenses	(1,374)	(1,213)	(2,893)	(1,982)
Income before income taxes	0	0	0	0
Assets	(122,856)	(68,207)	(122,856)	(68,207)
Goodwill	0	0	0	0
Core deposit intangibles & Other intangibles	0	0	0	0
Banking [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	91,645	88,127	181,409	174,842
Provision for credit losses	9,774	1,400	15,368	3,822
Noninterest revenues	14,991	21,921	33,672	39,269
Amortization of intangible assets	1,364	1,375	2,781	2,858
Acquisition expenses	3,372	1,194	3,741	1,728
Other operating expenses	59,130	60,578	123,330	120,347
Income before income taxes	32,996	45,501	69,861	85,356
Assets	13,272,929	10,534,555	13,272,929	10,534,555
Goodwill	689,128	629,916	689,128	629,916
Core deposit intangibles & Other intangibles	16,565	15,738	16,565	15,738
Employee Benefit Services [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	246	131	486	239
Provision for credit losses	0	0	0	0
Noninterest revenues	24,504	24,839	50,429	49,509
Amortization of intangible assets	1,411	1,669	2,905	3,438
Acquisition expenses	0	0	0	0
Other operating expenses	14,948	15,405	30,079	29,684
Income before income taxes	8,391	7,896	17,931	16,626
Assets	216,122	206,178	216,122	206,178
Goodwill	83,275	83,275	83,275	83,275
Core deposit intangibles & Other intangibles	34,870	41,107	34,870	41,107
All Other [Member] | Operating Segments [Member]
Information about reportable segments [Abstract]
Net interest income	60	42	110	78
Provision for credit losses	0	0	0	0
Noninterest revenues	14,817	15,159	30,352	29,606
Amortization of intangible assets	749	860	1,505	1,738
Acquisition expenses	0	0	0	0
Other operating expenses	11,303	11,308	23,118	22,017
Income before income taxes	2,825	3,033	5,839	5,929
Assets	78,022	72,862	78,022	72,862
Goodwill	20,312	20,312	20,312	20,312
Core deposit intangibles & Other intangibles	$ 8,611	$ 10,167	$ 8,611	$ 10,167