NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Deferred Financing Fees (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2017	Feb. 28, 2017
NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Deferred Financing Fees		$ 11.4	$ 16.2
Amortization of deferred financing fees		3.5	2.9	$ 1.8
Amortization and write-off of unamortized deferred financing fees		3.5	$ 2.9	1.8
Deferred finance charges					$ 4.8	$ 14.2
Write-off of unamortized deferred financing fees	$ 2.3	2.3		$ 3.9
Unamortized deferred financing fees expensed		$ 3.9