GOODWILL, OTHER INTANGIBLE ASSETS AND MORTGAGE SERVICING RIGHTS (Mortgage Servicing Rights) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Servicing Asset at Amortized Value, Balance [Roll Forward]
Servicing Asset at Amortized Cost, Additions		$ 166		$ 94		$ 0
Serviced Loans
Servicing Assets at Amortized Value [Line Items]
Loans serviced for others		2,360,000		2,190,000
Mortgage Servicing Rights
Servicing Assets at Amortized Value [Line Items]
Custodial accounts		11,100		10,200
Servicing Asset at Amortized Value, Balance [Roll Forward]
Balance, beginning of the year		14,738	[1]	15,249	[1]	13,295
Amounts capitalized		3,623		3,361		5,965
Amortization		(3,889)		(3,966)		(4,011)	[2]
Valuation adjustments in the period		0
Balance, end of the year	[1]	14,638		14,738		15,249
Valuation Allowance		$ 0		$ 0		$ 0

[1] (2) There was no valuation allowance as of December 31, 2018 and 2017.

[2] Amortization of mortgage servicing rights is recorded as a reduction of loan servicing income and any unamortized balance is fully written off if the loan repays in full.