COMPREHENSIVE INCOME (LOSS) - ADDITIONAL INFORMATION (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Cumulative foreign currency translation adjustment gain (loss)	$ 4,690.2	$ 5,094.9	$ 5,109.5	$ 5,133.0
Foreign Currency Translation Gain (Loss)
Derivative [Line Items]
Foreign currency tax adjustment	166.9	173.0
Cumulative foreign currency translation adjustment gain (loss)	(487.0)	(368.3)	$ (346.0)	$ (284.7)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest, Translation Gain (Loss)
Derivative [Line Items]
Cumulative foreign currency translation adjustment gain (loss)	(383.2)	(260.2)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest, Net Investment Hedges
Derivative [Line Items]
Cumulative foreign currency translation adjustment gain (loss)	$ (103.8)	$ (108.1)