DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents		$ 87.3	$ 87.1
Restricted cash		0.2	0.3
Total cash, cash equivalents and restricted cash	[1]	$ 87.5	$ 87.4	$ 186.8

[1] These amounts include restricted cash of $0.2 million and $0.3 million as of December 31, 2018 and 2017, respectively, which represent cash on deposit to support the Company's outstanding undrawn letters of credit and were included within other assets in the Company's consolidated balance sheets.