BUSINESS ACQUISITIONS, DISPOSITIONS, GOODWILL AND INTANGIBLE ASSETS - Finite and Indefinite-lived Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 2,502	$ 2,462
Accumulated Amortization	(2,019)	(1,913)
Indefinite-lived Intangible Assets [Line Items]
Total intangible assets, gross (excluding goodwill)	3,043	2,996
Trademarks and other
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets (excluding goodwill)	541	534
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Amount	1,506	1,479
Accumulated Amortization	(1,223)	(1,154)
Patents and trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Amount	293	287
Accumulated Amortization	(213)	(201)
Monitoring lines
Finite-Lived Intangible Assets [Line Items]
Gross Amount	67	67
Accumulated Amortization	(55)	(52)
Service portfolios and other
Finite-Lived Intangible Assets [Line Items]
Gross Amount	636	629
Accumulated Amortization	$ (528)	$ (506)