INCOME TAXES, Components of Net Deferred Tax Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Components of net deferred tax liability [Abstract]
Allowance for loan losses	$ 17,791	$ 17,476
Employee benefits	6,633	6,834
Debt extinguishment	613	904
Other, net	9,704	10,725
Deferred tax asset	34,741	35,939
Investment securities	38,314	37,527
Tax-deductible goodwill	39,724	35,842
Loan origination costs	7,295	6,792
Depreciation	886	3,722
Mortgage servicing rights	565	419
Pension	14,807	16,845
Deferred tax liability	101,591	101,147
Net deferred tax liability	$ (66,850)	$ (65,208)