(LOSS) EARNINGS PER SHARE - Schedule of Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ 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
Earnings Per Share [Abstract]
Net (loss) income attributable to Bausch Health Companies Inc.	$ (1,516)	$ (49)	$ (171)	$ (52)	$ (344)	$ (350)	$ (873)	$ (2,581)	$ (1,788)	$ (4,148)	$ 2,404
Basic weighted-average number of common shares outstanding (in shares)									352.1	351.3	350.2
Dilutive effect of stock options, RSUs and other (in shares)									0.0	0.0	1.6
Diluted weighted-average number of common shares outstanding (in shares)									352.1	351.3	351.8
(Loss) earnings per share attributable to Bausch Health Companies Inc.
Basic (in dollars per share)									$ (5.08)	$ (11.81)	$ 6.86
Diluted (in dollars per share)									$ (5.08)	$ (11.81)	$ 6.83