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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Retirement Benefits [Abstract]
Service cost	$ 2,234	$ 2,079	$ 6,895	$ 5,855
Interest cost	549	624	1,607	1,831
Expected return on plan assets	(2,515)	(2,443)	(7,603)	(7,382)
Amortization of prior service cost	(105)	(106)	(307)	(308)
Defined Benefit Plan, Amortization of Gain (Loss)	672	625	1,938	1,709
Net periodic benefit cost (income)	$ 835	$ 779	$ 2,530	$ 1,705