ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive Loss (Parenthetical) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Reclassification to net income	[1]	$ 2,556	$ 2,548	$ 1,661

[1] The Company reclassified amortization of prior service cost, actuarial loss and plan amendment cost for its retirement plan from accumulated other comprehensive loss to net income of $2.6 million, $2.5 million and $1.7 million for the years ended December 31, 2020, 2019 and 2018, respectively.