ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Accumulated Other Comprehensive Loss (Parenthetical) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Reclassification to net income	[1]	$ 1,661	$ 1,370	$ 1,084

[1] The Company reclassified amortization of plan amendment cost, prior service cost, and actuarial loss for its retirement plan from accumulated other comprehensive loss to net income of $1.7 million, $1.4 million and $1.1 million for the years ended December 31, 2018, 2017 and 2016, respectively.