INCOME TAXES, Components of Net Deferred Tax Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Components of net deferred tax liability [Abstract]
Allowance for loan losses	$ 12,059	$ 12,131
Employee benefits	5,393	4,479
Operating lease liabilities	9,801	0
Other, net	837	541
Deferred tax asset	28,090	17,151
Investment securities	21,547	14,451
Goodwill and intangibles	39,189	39,540
Operating lease right-of-use assets	9,566	0
Loan origination costs	7,639	6,851
Depreciation	2,736	3,098
Mortgage servicing rights	162	277
Pension	13,769	11,078
Deferred tax liability	94,608	75,295
Net deferred tax liability	$ (66,518)	$ (58,144)