ACQUISITIONS (Details) $ in Thousands	Feb. 03, 2017 USD ($)	Oct. 24, 2016 USD ($) Branch Location
Merchants Bancshares, Inc. [Member]
Business Acquisition [Line Items]
Purchase price of acquisition		$ 335,000
Deposits to be acquired		1,500,000
Assets acquired		$ 2,000,000
Merchants Bancshares, Inc. [Member] | VERMONT [Member]
Business Acquisition [Line Items]
Number of branch locations to be added upon merger | Branch		31
Merchants Bancshares, Inc. [Member] | MASSACHUSETTS [Member]
Business Acquisition [Line Items]
Number of branch locations to be added upon merger | Location		1
Northeast Retirement Services, Inc. [Member]
Business Acquisition [Line Items]
Purchase price of acquisition	$ 148,556
Tangible assets, net	$ 36,400
Factor of straight-line rate of depreciation used in declining balance depreciation method	150.00%
Period of amortization	10 years
Deferred tax liability	$ 24,200
Revenues earned	5,100
Expenses incurred	$ 3,600