REVENUES - Contract Balances (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Receivables	$ 572,373	$ 644,738
Contract assets (unbilled receivables)	44,761	56,326
Contract liabilities (deferred revenue)	$ 61,902	$ 73,370

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant