EMPLOYEE BENEFITS (Change in Fair Value of Pension Plan Assets) (Details) - Pension Benefits - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 199,466	$ 164,819
Fair value of plan assets at end of year	248,735	199,466
U.S. property separate account fund
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	22,114
Fair value of plan assets at end of year	22,269	22,114
U.S. property separate account fund | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	22,114	20,841
Unrealized gains	155	1,273
Fair value of plan assets at end of year	$ 22,269	$ 22,114