REVENUE - Contract Balances (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Trade accounts receivable, net		$ 188,772	$ 194,066	[1]
Contract assets	[2]	1,602	5,242
Contract liabilities	[3]	313	$ 930
Change in Contract with Customer, Liability [Abstract]
Contract liability, decrease from beginning of period		$ (600)

[1] Includes billed and unbilled amounts, net of allowance for credit losses. See Note 3 for details.

[2] Included in the “Prepaid expenses and other current assets” line on the consolidated balance sheet.

[3] Included in the “Other accrued liabilities” line of the consolidated balance sheet.