REVENUES (Contract Balances) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Revenue from Contract with Customer [Abstract]
Receivables	$ 608,645	$ 528,924	$ 531,696	$ 496,226
Contract Assets (Unbilled Receivables)	63,964	35,922	40,933	36,190
Contract Liabilities (Deferred Revenue)	$ 65,172	$ 67,822	$ 69,236	$ 64,397

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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	instant