EMPLOYEE BENEFITS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pension Benefits
Components of net periodic benefit cost and other amounts recognized in Other Comprehensive Income
Service cost	$ 293	$ 286	$ 585	$ 577
Interest cost	185	201	370	397
Expected return on plan assets	(520)	(510)	(1,040)	(965)
Amortization of net loss	112	104	225	203
Amortization of prior service credit	(19)	(19)	(38)	(38)
Amortization of transition obligation
Net periodic benefit cost	51	62	102	174
SERP Benefits
Components of net periodic benefit cost and other amounts recognized in Other Comprehensive Income
Service cost	52	44	105	88
Interest cost	26	26	52	52
Expected return on plan assets
Amortization of net loss	13	7	26	14
Amortization of prior service credit
Amortization of transition obligation	7	7	14	14
Net periodic benefit cost	$ 98	$ 84	$ 197	$ 168