EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS - Employee benefit plan amounts recognized in the Consolidated Balance Sheets and Consolidated Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Retirement Benefits [Abstract]
Service cost	$ 1,239	$ 1,309	$ 2,477	$ 2,617
Interest cost	589	581	1,178	1,162
Expected return on plan assets	(2,481)	(2,432)	(4,962)	(4,863)
Amortization of prior service cost	(104)	(104)	(207)	(207)
Defined Benefit Plan, Amortization of Gain (Loss)	439	421	877	841
Net periodic benefit cost (income)	$ (318)	$ (225)	$ (637)	$ (450)