REVENUE RECOGNITION - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Current deferred revenue	$ 386,943	$ 360,000	$ 360,015
Noncurrent deferred revenue	1,500	$ 1,700
Deferred revenue recognized during period	234,800
Noncurrent capitalized sales commissions	$ 42,300		$ 40,500

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 noncurrent.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
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-Publisher FASB
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-Topic 606
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=82913815&loc=SL49130531-203044

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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