REVENUE - Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Contract asset (current)	$ 16,878	$ 16,109
Increase / (decrease) in contract asset (current)	769
Contract liability (current)	86,340	87,188
Increase / (decrease) in contract liability (current)	(848)
Contract liability (long-term)	21,905	$ 21,584
Increase / (decrease) in contract liability (long-term)	321
Revenue recognized previously included in current contract liabilities	126,100
Revenue recognized previously included in current contract liabilities at the beginning of the year	$ 65,300