RESTRICTED CASH - Restatement (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Jan. 01, 2017
Cash, restricted cash and cash equivalents
Net cash used in investing activities	$ (65.7)	$ (13.8)
Cash, cash equivalents, and restricted cash at beginning of period	217.2	169.4
Cash, cash equivalents, and restricted cash at end of period	126.3	147.1
Restricted cash	$ 0.0	8.6	$ 9.1	$ 9.1
As Reported
Cash, restricted cash and cash equivalents
Net cash used in investing activities		(13.3)
Cash, cash equivalents, and restricted cash at beginning of period		160.3
Cash, cash equivalents, and restricted cash at end of period		138.5
Adjustments
Cash, restricted cash and cash equivalents
Net cash used in investing activities		(0.5)
Cash, cash equivalents, and restricted cash at beginning of period		9.1
Cash, cash equivalents, and restricted cash at end of period		$ 8.6