REVENUE AND RECEIVABLES - Contract Acquisition Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Contract Acquisition Costs
Amortization of contract acquisition cost	$ 2.8	$ 2.1
Prepayments and other current assets
Contract Acquisition Costs
Short-term contract acquisition costs	2.2	1.9
Other Assets
Contract Acquisition Costs
Long-term contract acquisition costs	$ 2.3	$ 1.2