RETIREMENT PLANS - Information Related to Pension and Postretirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized in Consolidated Balance Sheet:
Other assets			$ 33.0	$ 31.1
Postretirement health care and pension benefits			(1,226.2)	(1,084.4)
Amounts recognized in Accumulated Other Comprehensive Loss (Income):
Accumulated other comprehensive loss (income), net of tax			935.2	823.8
Change in Accumulated Other Comprehensive Loss (Income):
Other comprehensive loss (income)			78.1	251.6	$ (18.0)
Aggregate projected benefit obligation, accumulated benefit obligation and fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets:
Aggregate projected benefit obligation			4,155.4	3,970.3
Accumulated benefit obligation			4,098.6	3,877.4
Fair value of plan assets			3,085.2	3,040.5
Discontinued Operations
Defined Benefit Plan Disclosure
Accumulated Benefit Obligation, end of year				1.1
Projected Benefit Obligation
Projected benefit obligation, beginning of year			5.3
Service cost			2.5	7.8	7.1
Projected benefit obligation, end of year				5.3
Plan Assets
Fair value of plan assets, beginning of year			0.6
Fair value of plan assets, end of year				0.6
Amounts recognized in Accumulated Other Comprehensive Loss (Income):
Accumulated other comprehensive loss (income), net of tax				2.9
Aggregate projected benefit obligation, accumulated benefit obligation and fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets:
Fair value of plan assets				0.6
Non-qualified plan
Projected Benefit Obligation
Projected benefit obligation, beginning of year			127.0
Projected benefit obligation, end of year			134.0	127.0
United States | Pension
Defined Benefit Plan Disclosure
Accumulated Benefit Obligation, end of year			2,728.4	2,535.9
Projected Benefit Obligation
Projected benefit obligation, beginning of year			2,562.5	2,241.0
Service cost			68.4	72.8	74.5
Interest cost			70.3	89.0	83.1
Curtailments and settlements			(0.6)	3.4
Plan amendments	$ (40.4)
Actuarial (gain) loss			241.8	336.4
Benefits paid			(214.0)	(180.1)
Projected benefit obligation, end of year	2,241.0		2,728.4	2,562.5	2,241.0
Plan Assets
Fair value of plan assets, beginning of year			2,292.9	1,981.4
Actual returns on plan assets			281.3	366.9
Company contributions			13.3	129.0
Curtailments and settlements			(0.6)	(4.3)
Benefits paid			(214.0)	(180.1)
Fair value of plan assets, end of year	1,981.4		2,372.9	2,292.9	1,981.4
Funded Status, end of year			(355.5)	(269.6)
Amounts recognized in Consolidated Balance Sheet:
Other current liabilities			(14.7)	(12.5)
Postretirement health care and pension benefits			(340.8)	(257.1)
Net liability			(355.5)	(269.6)
Amounts recognized in Accumulated Other Comprehensive Loss (Income):
Unrecognized net actuarial loss (gain)			691.3	632.4
Unrecognized net prior service costs (benefits)			(32.7)	(40.0)
Tax (benefit) expense			(165.1)	(149.1)
Accumulated other comprehensive loss (income), net of tax			493.5	443.3
Change in Accumulated Other Comprehensive Loss (Income):
Amortization of net actuarial (gain) loss			(51.8)	(23.5)
Amortization of prior service costs			7.4	11.5
Current period net actuarial loss (gain)			113.3	119.0
Curtailments and settlements			(2.7)	(1.5)
Tax (benefit) expense			(16.0)	(25.7)
Other comprehensive loss (income)			50.2	79.8
Estimated amounts in accumulated other comprehensive loss expected to be reclassified to net period cost during 2021
Net actuarial loss (gain)			64.8
Net prior service costs (benefits)			(6.9)
Total			57.9
United States | Postretirement Health Care
Defined Benefit Plan Disclosure
Accumulated Benefit Obligation, end of year			172.4	165.7
Projected Benefit Obligation
Projected benefit obligation, beginning of year			165.7	147.3
Service cost			1.2	1.4	2.7
Interest cost			4.4	5.6	5.6
Participant contributions			3.8	3.4
Curtailments and settlements				0.6
Plan amendments		$ (18.9)
Actuarial (gain) loss			12.2	22.2
Benefits paid			(14.9)	(14.8)
Projected benefit obligation, end of year	147.3		172.4	165.7	147.3
Plan Assets
Fair value of plan assets, beginning of year			6.1	6.0
Actual returns on plan assets			0.8	1.1
Company contributions			13.7	13.8
Benefits paid			(14.9)	(14.8)
Fair value of plan assets, end of year	6.0		5.7	6.1	6.0
Funded Status, end of year			(166.7)	(159.6)
Amounts recognized in Consolidated Balance Sheet:
Other current liabilities			(5.5)	(5.2)
Postretirement health care and pension benefits			(161.2)	(154.4)
Net liability			(166.7)	(159.6)
Amounts recognized in Accumulated Other Comprehensive Loss (Income):
Unrecognized net actuarial loss (gain)			1.3	(10.5)
Unrecognized net prior service costs (benefits)				(11.0)
Tax (benefit) expense			(2.0)	3.4
Accumulated other comprehensive loss (income), net of tax			(0.7)	(18.1)
Change in Accumulated Other Comprehensive Loss (Income):
Amortization of net actuarial (gain) loss			(0.1)	4.1
Amortization of prior service costs			11.0	23.2
Current period net actuarial loss (gain)			11.9	21.4
Curtailments and settlements				0.2
Tax (benefit) expense			(5.4)	(11.7)
Other comprehensive loss (income)			17.4	37.2
Estimated amounts in accumulated other comprehensive loss expected to be reclassified to net period cost during 2021
Net actuarial loss (gain)			0.7
Total			0.7
International | Pension
Defined Benefit Plan Disclosure
Accumulated Benefit Obligation, end of year			1,759.8	1,585.5
Projected Benefit Obligation
Projected benefit obligation, beginning of year			1,667.6	1,436.7
Service cost			30.8	30.2	33.2
Interest cost			22.3	31.2	29.1
Participant contributions			2.6	3.0
Curtailments and settlements			(34.3)	(18.6)
Plan amendments			(1.7)	0.1
Actuarial (gain) loss			83.6	235.8
Other events			0.3	0.6
Benefits paid			(39.6)	(37.6)
Foreign currency translation			102.6	(13.8)
Projected benefit obligation, end of year	1,436.7		1,834.2	1,667.6	1,436.7
Plan Assets
Fair value of plan assets, beginning of year			1,027.1	925.6
Actual returns on plan assets			87.7	110.5
Company contributions			41.3	43.3
Participant contributions			2.6	3.0
Curtailments and settlements			(25.7)	(17.6)
Benefits paid			(39.6)	(37.6)
Foreign currency translation			54.6	(0.1)
Fair value of plan assets, end of year	$ 925.6		1,148.0	1,027.1	$ 925.6
Funded Status, end of year			(686.2)	(640.5)
Amounts recognized in Consolidated Balance Sheet:
Other assets			37.0	31.1
Other current liabilities			(24.0)	(23.6)
Postretirement health care and pension benefits			(699.2)	(647.8)
Net liability			(686.2)	(640.3)
Amounts recognized in Accumulated Other Comprehensive Loss (Income):
Unrecognized net actuarial loss (gain)			595.6	527.7
Unrecognized net prior service costs (benefits)			(1.2)	0.6
Tax (benefit) expense			(151.9)	(129.6)
Accumulated other comprehensive loss (income), net of tax			442.5	398.7
Change in Accumulated Other Comprehensive Loss (Income):
Amortization of net actuarial (gain) loss			(29.5)	(17.3)
Amortization of prior service costs			(0.2)	1.1
Current period net actuarial loss (gain)			66.4	185.8
Current period prior service costs			(1.7)	0.1
Curtailments and settlements			(2.2)	1.8
Tax (benefit) expense			(22.3)	(36.9)
Foreign currency translation			33.3	(5.2)
Other comprehensive loss (income)			43.8	$ 129.4
Estimated amounts in accumulated other comprehensive loss expected to be reclassified to net period cost during 2021
Net actuarial loss (gain)			28.5
Net prior service costs (benefits)			(0.2)
Total			$ 28.3