REVENUE RECOGNITION - Schedule of Assets and Liabilities Associated with Contracts from Customers (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Accounts receivable	$ 82,261	$ 60,452
Short-term deferred revenue	105,215	97,333
Long-term deferred revenue	57,086	$ 47,529
Other Current Assets [Member]
Disaggregation Of Revenue [Line Items]
Short-term unbilled receivables	6,659
Other Assets [Member]
Disaggregation Of Revenue [Line Items]
Long-term unbilled receivables	$ 3,770