SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Revenue Recognition (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Jan. 01, 2018	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Enacted Corporate Tax			35.00%
New Enacted Corporate Tax Rate			21.00%
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				$ 0
Services Revenues [Member]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 11,100
Deferred Revenue [Domain]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				$ 41,800
Minimum [Member]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 95,000
Maximum [Member]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 115,000