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
	Mar. 31, 2019	Mar. 31, 2018
Retirement Benefits [Abstract]
Service cost	$ 1,750	$ 1,295
Interest cost	700	590
Expected return on plan assets	(2,450)	(2,460)
Amortization of prior service cost	(100)	(103)
Defined Benefit Plan, Amortization of Gain (Loss)	475	522
Net periodic benefit cost (income)	$ 375	$ (156)