REVENUE RECOGNITION - Summary of Contract Assets and Contract Liabilities from Contracts with Customers (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Receivables	$ 81,715	$ 78,938
Short-term contract assets (Prepaid expenses and other assets)	13,595	13,516
Long-term contract assets (Other assets)	34,683	34,148
Short-term contract liabilities (Deferred revenues)	32,916	33,119
Long-term contract liabilities (Deferred revenues)	$ 78,393	$ 76,911

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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