DEBT - Schedule of Outstanding Letters of Credit, Unused Portion of Senior Credit Facility And Other Letters of Credit Outstanding (Detail) - Senior credit facility - Line of credit - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Outstanding letters of credit under senior credit facility	$ 50.4	$ 63.1
Unused portion of the revolving credit facility	515.7	553.6
Other letters of credit outstanding	$ 52.2	$ 52.2