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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Retirement Benefits [Abstract]
Service cost	$ 1,649	$ 1,736	$ 4,944	$ 4,766
Interest cost	694	601	2,083	1,792
Expected return on plan assets	(2,429)	(2,450)	(7,288)	(7,360)
Amortization of prior service cost	(104)	(104)	(310)	(310)
Defined Benefit Plan, Amortization of Gain (Loss)	451	556	1,352	1,633
Net periodic benefit cost (income)	$ 261	$ 339	$ 781	$ 521