COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Outstanding letters of credit	$ 15.4		$ 15.4		$ 15.3
Amount of outstanding surety bonds	211.3		211.3		$ 101.2
Rent expense	2.0	$ 2.3	4.1	$ 5.0
Guarantee Obligations | Downtown Columbia
Lessor, Lease, Description [Line Items]
Loss contingency guaranteed amount limit	$ 1.0		$ 1.0