RESTRUCTURING, DIVESTITURES, AND IMPAIRMENTS - Additional Information (Detail) - USD ($) $ in Millions			1 Months Ended		3 Months Ended								12 Months Ended
	Dec. 01, 2020	Apr. 06, 2020	Aug. 31, 2020	Aug. 31, 2019	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charges															$ 9.1
Operational optimization charges													$ 3.1	$ 14.5	29.4
Gain (loss) on disposition of business					$ 42.6	$ (104.1)	$ (3.8)	$ (58.3)	$ (24.9)	$ (83.2)	$ (0.3)	$ 5.4	(123.6)	(103.0)	(12.8)
Proceeds from sale of business													498.9	86.6	25.2
Impairment charges and subsequent loss on disposal													123.6	103.0	12.8
H S A
Restructuring Cost and Reserve [Line Items]
Service agreement period		7 years
Proceeds from stock purchase agreement deferred		$ 17.7
Transmission Service Agreement
Restructuring Cost and Reserve [Line Items]
Service agreement period		6 months
Proceeds from stock purchase agreement deferred		$ 1.5
ESOL Disposal Group
Restructuring Cost and Reserve [Line Items]
Consideration for sale of business		$ 462.5
Revenue														559.6
Impairment of long-lived assets to be disposed of													53.8
Estimated deal costs													11.1
Argentina
Restructuring Cost and Reserve [Line Items]
Cumulative currency translation loss realized through disposition of operations													87.2	0.0	0.0
Mexico
Restructuring Cost and Reserve [Line Items]
Cumulative currency translation loss realized through disposition of operations													0.0	18.9	0.0
Chile
Restructuring Cost and Reserve [Line Items]
Cumulative currency translation loss realized through disposition of operations													0.0	16.8	0.0
Expert Solutions | Disposal group, disposed of by sale, not discontinued operations
Restructuring Cost and Reserve [Line Items]
Consideration for sale of business	$ 78.0
Revenue														75.4
Transaction costs	2.7
TAS
Restructuring Cost and Reserve [Line Items]
Transaction services agreement period		15 months
Allocated and deferred amount									5.1					5.1
TAS | North America
Restructuring Cost and Reserve [Line Items]
Consideration for sale of business									$ 36.4					36.4
Gain (loss) on disposition of business														(45.5)
Non-Core Clean Room Business | Disposal group, disposed of by sale, not discontinued operations
Restructuring Cost and Reserve [Line Items]
Proceeds from sale of business															17.0
Impairment charges and subsequent loss on disposal															6.9
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges															3.7
Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Impairment of long-lived assets to be disposed of													2.8	1.7	12.3
Selling, general and administrative expenses | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges														5.5
Cost of sales
Restructuring Cost and Reserve [Line Items]
Impairment of long-lived assets to be disposed of													0.0	5.6	0.0
North America
Restructuring Cost and Reserve [Line Items]
Operational optimization charges														3.8
Impairment charges and subsequent loss on disposal													15.0	45.5	6.9
North America | ESOL Disposal Group
Restructuring Cost and Reserve [Line Items]
Revenue														100.0
North America | Expert Solutions | Disposal group, disposed of by sale, not discontinued operations
Restructuring Cost and Reserve [Line Items]
Gain (loss) on disposition of business	38.8
North America | Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Impairment of long-lived assets to be disposed of													0.0	0.4	1.0
North America | Selling, general and administrative expenses | Customer Lists
Restructuring Cost and Reserve [Line Items]
Impairment of long-lived assets to be disposed of													1.7
North America | Cost of sales
Restructuring Cost and Reserve [Line Items]
Impairment of long-lived assets to be disposed of													0.0	2.0	0.0
North America | Cost of sales | Software
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charges															7.4
North America | Cost of sales | Other long-term assets
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charges															0.3
Other | Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charges															1.4
International
Restructuring Cost and Reserve [Line Items]
Operational optimization charges														10.7
Impairment charges and subsequent loss on disposal													108.6	57.5	5.9
International | Argentina | Disposal group, disposed of by sale, not discontinued operations
Restructuring Cost and Reserve [Line Items]
Gain (loss) on disposition of business														(112.4)
Proceeds from sale of business			$ 3.9
Cumulative currency translation loss realized through disposition of operations														$ 87.2
International | Argentina | Disposal group, disposed of by sale, not discontinued operations | Total Revenues
Restructuring Cost and Reserve [Line Items]
Customer concentration risk percentage, no more than														1.00%
International | United Kingdom
Restructuring Cost and Reserve [Line Items]
Operational optimization charges													3.1
Consideration for sale of business															11.5
Proceeds from sale of business															8.2
Impairment charges and subsequent loss on disposal														$ 0.7	16.5
Consideration from business sale held in escrow				$ 3.0
International | United Kingdom | Patient transport services
Restructuring Cost and Reserve [Line Items]
Gain (loss) on disposition of business														0.3
International | United Kingdom | Disposal group, disposed of by sale, not discontinued operations
Restructuring Cost and Reserve [Line Items]
Gain (loss) on disposition of business														5.1
Proceeds from sale of business														14.8
International | Mexico
Restructuring Cost and Reserve [Line Items]
Impairment charges and subsequent loss on disposal														43.2
Cumulative foreign currency translation adjustment														(18.9)
International | Chile
Restructuring Cost and Reserve [Line Items]
Gain (loss) on disposition of business														(19.0)
Proceeds from sale of business														30.7
Cumulative foreign currency translation adjustment														(16.8)
International | Expert Solutions | Disposal group, disposed of by sale, not discontinued operations
Restructuring Cost and Reserve [Line Items]
Gain (loss) on disposition of business	$ 4.0
International | Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Impairment of long-lived assets to be disposed of													2.8	1.3	11.3
International | Cost of sales
Restructuring Cost and Reserve [Line Items]
Impairment of long-lived assets to be disposed of													$ 0.0	$ 3.6	$ 0.0