ACCUMULATED OTHER COMPREHENSIVE INCOME, NET (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
AOCI Rollforward
Beginning balance	$ 3,355.6	$ 3,241.0
Other comprehensive income (loss)	(37.5)	14.7
Ending balance	3,310.1	3,285.4
Accumulated Other Comprehensive Income, net
AOCI Rollforward
Beginning balance	37.6	11.5
Other comprehensive income (loss)	(37.5)	14.7
Ending balance	0.1	$ 26.2
Foreign Currency Translation
AOCI Rollforward
Beginning balance	38.2
Other comprehensive income (loss)	(37.5)
Ending balance	0.7
Unrealized Investment Gain/Loss
AOCI Rollforward
Beginning balance	0.2
Ending balance	0.2
Post-Retirement Benefits
AOCI Rollforward
Beginning balance	(0.8)
Ending balance	$ (0.8)