SUPPLEMENTAL CASH FLOW AND OTHER DATA (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow and Other Data [Line Items]
Amortization expense	$ 27	$ 25	$ 30	$ 29	$ 28	$ 27	$ 26	$ 26	$ 96	$ 90	$ 74
Depreciation expense									233	219	196
Depreciation and amortization expense									329	309	270
Interest expense									(180)	(169)	(153)
Interest income									5	2	2
Interest expense, net									(175)	(167)	(151)
Interest paid									192	174	159
Income taxes paid									202	84	243
Accounts payable associated with capital expenditures									26	11	26
Accounts payable associated with purchases of treasury stock	0				3				0	3	0
Dividend payable	71				71				71	71	61
Fair value of assets acquired									63	453	657
Fair value of liabilities assumed									0	7	58
Fair value of net assets acquired									63	446	599
Merger consideration payable									(5)	(19)	(6)
Cash paid for business acquisitions									58	427	593
Less: cash acquired										6	12
Business acquisitions, net of cash acquired									58	421	581
Leases:
Operating cash flows from operating leases									180
Operating cash flows from finance leases									3
Financing cash flows from finance leases									4
Leased assets obtained in exchange for new operating lease liabilities									164
Leased assets obtained in exchange for new finance lease liabilities									1
Leased assets obtained in exchange for new finance lease liabilities										1	7
Intangible Assets
Supplemental Cash Flow and Other Data [Line Items]
Amortization expense	$ 24	$ 23	$ 25	$ 24	$ 24	$ 22	$ 22	$ 22	$ 96	$ 90	$ 74