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	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Outstanding letters of credit under Senior Credit Facility	$ 36.2	$ 63.1
Unused portion of the Senior Credit Facility	432.3	553.6
Other letters of credit outstanding	$ 52.3	$ 52.2