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, 2020	Mar. 31, 2019
Retirement Benefits [Abstract]
Service cost	$ 1,850	$ 1,750
Interest cost	600	700
Expected return on plan assets	(2,475)	(2,450)
Amortization of prior service cost	(100)	(100)
Defined Benefit Plan, Amortization of Gain (Loss)	525	475
Net periodic benefit cost (income)	$ 400	$ 375