SUMMARY OF SIGNIFICANT ACCOUNTING AND BUSINESS POLICIES, Revenue Recognition (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue Recognition [Abstract]
Revenues recognized on contracts in process	$ 40.6	$ 31.5	$ 47.5
Minimum [Member]
Deferred Revenue Arrangement [Line Items]
Service revenue contract term	1 year
Maximum [Member]
Deferred Revenue Arrangement [Line Items]
Service revenue contract term	2 years