RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans to Related Parties [Roll Forward]
Balance at beginning of year	$ 36,911	$ 37,802
New loans or additional advances	5,742	7,116
Repayments	(7,184)	(8,007)
Balance at end of year	35,469	36,911	$ 37,802
Deposit liabilities	10,300	11,800
Legal services	1,200	0	4,250
Fee income	$ 49,677	48,271	47,139
Minimum
Related Party Transactions [Line Items]
Related party principal ownership threshold (in hundredths)	10.00%
Director
Loans to Related Parties [Roll Forward]
Legal services	$ 36	88	67
7 Southside Drive, Clifton Park, New York \| Director
Loans to Related Parties [Roll Forward]
Monthly rent expense	4
25 Park Avenue, Clifton Park, New York \| Director
Loans to Related Parties [Roll Forward]
Monthly rent expense	11
1365 New Scotland Road, Slingerlands, New York \| Director
Loans to Related Parties [Roll Forward]
Monthly rent expense	4
Rent expense	169	90	73
127 Court Street, Binghamton, New York \| Director
Loans to Related Parties [Roll Forward]
Monthly rent expense	5
Rent expense	62
Participating mortgage loans, amount sold	1,900
Participating mortgage loans, participation liabilities, amount	4,700
Participating mortgage loans, income(loss) From Insurance Products	2
WMG \| Operating Segments
Loans to Related Parties [Roll Forward]
Legal services			4,250
WMG \| Operating Segments \| Trust Services \| Management
Loans to Related Parties [Roll Forward]
Fee income	$ 328	$ 904	$ 1,000

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Participating Mortgage Loans, Amount Sold

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Participating Mortgage Loans, Income(Loss) From Insurance Products

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For a designation as a related party, the threshold percentage of principal ownership in an entity, above which the party is considered a related party..

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The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

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Reflects the amount of new advances made to related parties in the form of loan and lease receivables.

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Amount of cash inflow from related parties which reduce the amount of loans and leases receivable due from related parties.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay.

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The aggregate amount of the participation liability at the end of the accounting period.

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Amount of deposits held by the entity for a related party (entity, shareholder, employee).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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