RESTRUCTURING AND OTHER COSTS - RESTRUCTURING ACCRUALS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 32.5	$ 41.2
Provisions and adjustments	59.8	25.7
Amounts applied	(28.1)	(29.5)
Change in estimates	(3.9)	(4.9)
Ending Balance	60.3	32.5
Severances
Restructuring Reserve [Roll Forward]
Beginning Balance	28.8	36.1
Provisions and adjustments	51.2	16.1
Amounts applied	(20.4)	(22.1)
Change in estimates	(3.7)	(1.3)
Ending Balance	55.9	28.8
Severances | 2015 and Prior Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	20.6
Provisions and adjustments	0.6
Amounts applied	(10.4)
Change in estimates	(4.8)
Ending Balance	6.0	20.6
Severances | 2016 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	8.2	0.0
Provisions and adjustments	0.0	11.4
Amounts applied	(5.8)	(2.8)
Change in estimates	(0.7)	(0.4)
Ending Balance	1.7	8.2
Severances | 2017 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.0
Provisions and adjustments	50.6
Amounts applied	(4.2)
Change in estimates	1.8
Ending Balance	48.2	0.0
Severances | 2014 and Prior Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.6	1.5
Provisions and adjustments		0.0
Amounts applied		(0.8)
Change in estimates		(0.1)
Ending Balance		0.6
Severances | 2015 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	20.0	34.6
Provisions and adjustments		4.7
Amounts applied		(18.5)
Change in estimates		(0.8)
Ending Balance		20.0
Lease/Contract Terminations
Restructuring Reserve [Roll Forward]
Beginning Balance	3.0	4.2
Provisions and adjustments	1.2	5.9
Amounts applied	(2.9)	(3.9)
Change in estimates	(0.7)	(3.2)
Ending Balance	0.6	3.0
Lease/Contract Terminations | 2015 and Prior Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	2.7
Provisions and adjustments	0.7
Amounts applied	(2.3)
Change in estimates	(0.5)
Ending Balance	0.6	2.7
Lease/Contract Terminations | 2016 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.3	0.0
Provisions and adjustments	0.0	0.5
Amounts applied	(0.3)	(0.2)
Change in estimates	(0.2)	0.0
Ending Balance	(0.2)	0.3
Lease/Contract Terminations | 2017 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.0
Provisions and adjustments	0.5
Amounts applied	(0.3)
Change in estimates	0.0
Ending Balance	0.2	0.0
Lease/Contract Terminations | 2014 and Prior Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.2	0.8
Provisions and adjustments		0.0
Amounts applied		(0.4)
Change in estimates		(0.2)
Ending Balance		0.2
Lease/Contract Terminations | 2015 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	2.5	3.4
Provisions and adjustments		5.4
Amounts applied		(3.3)
Change in estimates		(3.0)
Ending Balance		2.5
Other Restructuring Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	0.7	0.9
Provisions and adjustments	7.4	3.7
Amounts applied	(4.8)	(3.5)
Change in estimates	0.5	(0.4)
Ending Balance	3.8	0.7
Other Restructuring Costs | 2015 and Prior Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.5
Provisions and adjustments	2.4
Amounts applied	(1.5)
Change in estimates	0.5
Ending Balance	1.9	0.5
Other Restructuring Costs | 2016 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.2	0.0
Provisions and adjustments	2.0	0.5
Amounts applied	(2.0)	(0.3)
Change in estimates	0.0	0.0
Ending Balance	0.2	0.2
Other Restructuring Costs | 2017 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.0
Provisions and adjustments	3.0
Amounts applied	(1.3)
Change in estimates	0.0
Ending Balance	1.7	0.0
Other Restructuring Costs | 2014 and Prior Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	0.2	0.3
Provisions and adjustments		0.1
Amounts applied		(0.2)
Change in estimates		0.0
Ending Balance		0.2
Other Restructuring Costs | 2015 Plans
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 0.3	0.6
Provisions and adjustments		3.1
Amounts applied		(3.0)
Change in estimates		(0.4)
Ending Balance		$ 0.3