SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 9,688.6
Other comprehensive income (loss) before reclassifications:
Increase (decrease)	(4.2)	$ (133.8)	$ (41.0)
Income tax impact	3.8	(10.3)	(6.2)
Other comprehensive income (loss) before reclassifications, net of income taxes	(0.4)	(144.1)	(47.2)
Amounts reclassified from AOCI into income:
Increase (decrease)	0.1	3.6	4.3
Income tax impact	(0.1)	(0.2)	(1.0)
Amounts reclassified from AOCI into income, net of income taxes:	0.0	3.4	3.3
Total other comprehensive income (loss), net of income taxes	(0.4)	(140.7)	(43.9)
Ending balance	10,325.3	9,688.6
Foreign currency translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(301.4)	(122.7)	(54.0)
Other comprehensive income (loss) before reclassifications:
Increase (decrease)	9.7	(181.4)	(68.7)
Income tax impact	0.0	0.0	0.0
Other comprehensive income (loss) before reclassifications, net of income taxes	9.7	(181.4)	(68.7)
Amounts reclassified from AOCI into income:
Increase (decrease)	0.0	2.7	0.0
Income tax impact	0.0	0.0	0.0
Amounts reclassified from AOCI into income, net of income taxes:	0.0	2.7	0.0
Total other comprehensive income (loss), net of income taxes	9.7	(178.7)	(68.7)
Ending balance	(291.7)	(301.4)	(122.7)
Pension & post-retirement plan benefit adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(24.3)	(62.3)	(87.1)
Other comprehensive income (loss) before reclassifications:
Increase (decrease)	(13.9)	47.6	27.7
Income tax impact	3.8	(10.3)	(6.2)
Other comprehensive income (loss) before reclassifications, net of income taxes	(10.1)	37.3	21.5
Amounts reclassified from AOCI into income:
Increase (decrease)	0.1	0.9	4.3
Income tax impact	(0.1)	(0.2)	(1.0)
Amounts reclassified from AOCI into income, net of income taxes:	0.0	0.7	3.3
Total other comprehensive income (loss), net of income taxes	(10.1)	38.0	24.8
Ending balance	(34.4)	(24.3)	(62.3)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(325.7)	(185.0)	(141.1)
Amounts reclassified from AOCI into income:
Total other comprehensive income (loss), net of income taxes	(0.4)	(140.7)	(43.9)
Ending balance	$ (326.1)	$ (325.7)	$ (185.0)