INTANGIBLE ASSETS AND GOODWILL - Narrative (Details) - USD ($)					3 Months Ended									6 Months Ended	12 Months Ended
	Oct. 01, 2019	Oct. 01, 2018	Jan. 01, 2018	Oct. 01, 2017	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Mar. 01, 2018	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets															$ 58,000,000
Impairment of long-lived assets															8,000,000
Impairment of finite-lived intangible assets															5,000,000
Impairment of indefinite-lived intangible assets															4,000,000
Carrying value of intangible assets, net					$ 10,201,000,000				$ 12,001,000,000						10,201,000,000	$ 12,001,000,000
Finite-lived intangible assets					8,490,000,000				10,267,000,000						8,490,000,000	10,267,000,000
Net (loss) income attributable to Bausch Health Companies Inc.					$ (1,516,000,000)	$ (49,000,000)	$ (171,000,000)	$ (52,000,000)	$ (344,000,000)	$ (350,000,000)	$ (873,000,000)	$ (2,581,000,000)			(1,788,000,000)	(4,148,000,000)	$ 2,404,000,000
Decrease to earnings per share, basic and diluted (in dollars per share)					$ 4.30	$ 0.14	$ 0.49	$ 0.15	$ 0.98	$ 1.00	$ 2.49	$ 7.36
Goodwill reallocated into (out of)					$ 13,126,000,000				$ 13,142,000,000						13,126,000,000	13,142,000,000	15,593,000,000		$ 15,794,000,000
Goodwill impairments	$ 0														0	2,322,000,000	312,000,000
Accumulated goodwill impairment charges to date					3,711,000,000										3,711,000,000
Salix Reporting Unit
Finite-Lived Intangible Assets [Line Items]
Goodwill reallocated into (out of)				$ 5,127,000,000
Goodwill impairments				0
Total identifiable net assets				10,660,000,000
Aggregate purchase price, net				$ 13,404,000,000
Ortho Dermatologics Reporting Unit
Finite-Lived Intangible Assets [Line Items]
Goodwill impairments											$ 0					2,213,000,000
Percentage of fair value in excess of carrying value											5.00%			5.00%
Dentistry Reporting Unit
Finite-Lived Intangible Assets [Line Items]
Goodwill impairments		$ 109,000,000														109,000,000
Reporting Units Excluding Dentistry
Finite-Lived Intangible Assets [Line Items]
Goodwill impairments		$ 0
Reporting Units Excluding Ortho Dermatologics and Dentistry
Finite-Lived Intangible Assets [Line Items]
Percentage of fair value in excess of carrying value		15.00%
Baush and Lomb/International Segment | Scenario, Adjustment
Finite-Lived Intangible Assets [Line Items]
Goodwill reallocated into (out of)																			$ 264,000,000
Branded Rx Segment
Finite-Lived Intangible Assets [Line Items]
Goodwill impairments													$ 312,000,000
Branded Rx Segment | Scenario, Adjustment
Finite-Lived Intangible Assets [Line Items]
Goodwill reallocated into (out of)																		$ 115,000,000
Branded Rx Segment | Salix Reporting Unit
Finite-Lived Intangible Assets [Line Items]
Goodwill impairments			$ 1,970,000,000
Branded Rx Segment | Ortho Dermatologics Reporting Unit
Finite-Lived Intangible Assets [Line Items]
Goodwill impairments			$ 243,000,000
Bausch Lomb/International And U.S. Diversified Products Segments | Scenario, Adjustment
Finite-Lived Intangible Assets [Line Items]
Goodwill reallocated into (out of)												$ (115,000,000)
Maximum
Finite-Lived Intangible Assets [Line Items]
Reporting unit, impairment test, long-term growth rates	2.00%
Reporting unit, impairment test, estimated cash flows, discount rate	9.80%
Minimum
Finite-Lived Intangible Assets [Line Items]
Reporting unit, impairment test, long-term growth rates	1.50%
Reporting unit, impairment test, estimated cash flows, discount rate	9.00%
Product rights/patents
Finite-Lived Intangible Assets [Line Items]
Impairment of finite-lived intangible assets																55,000,000	95,000,000
Finite-lived intangible assets					410,000,000				634,000,000						$ 410,000,000	$ 634,000,000
Estimated useful lives															4 years
Product rights/patents | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives															15 years
Product rights/patents | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives															3 years
Certain Product Brands
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets																	$ 7,618,000,000
Estimated useful lives																4 years	7 years
Corporate brands
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets					592,000,000				$ 663,000,000						$ 592,000,000	$ 663,000,000
Estimated useful lives															8 years
Corporate brands | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives															20 years
Corporate brands | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives															7 years
Held For Sale
Finite-Lived Intangible Assets [Line Items]
Impairment of long-lived assets																5,000,000	$ 114,000,000
Held For Sale | Sprout
Finite-Lived Intangible Assets [Line Items]
Impairment of long-lived assets																	351,000,000
Acquired IPR&D
Finite-Lived Intangible Assets [Line Items]
Impairment of indefinite-lived intangible assets																28,000,000	3,000,000
Uceris
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets														$ 263,000,000		348,000,000
Carrying value of intangible assets, net					47,000,000										$ 47,000,000
Arestin
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets																$ 132,000,000
Other Product Lines
Finite-Lived Intangible Assets [Line Items]
Impairment of finite-lived intangible assets																	151,000,000
Salix | Corporate brands
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets																	$ 569,000,000
Estimated useful lives																10 years	17 years
Xifaxan
Finite-Lived Intangible Assets [Line Items]
Carrying value of intangible assets, net					$ 4,309,000,000										4,309,000,000
Xifaxan | Intangible Assets, Amortization Period
Finite-Lived Intangible Assets [Line Items]
Net (loss) income attributable to Bausch Health Companies Inc.															$ 473,000,000	$ 143,000,000
Decrease to earnings per share, basic and diluted (in dollars per share)															$ 1.34	$ 0.41