(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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income (loss) attributable to Bausch Health Companies Inc.	$ (344)	$ (350)	$ (873)	$ (2,581)	$ 513	$ 1,301	$ (38)	$ 628	$ (4,148)	$ 2,404	$ (2,409)
Basic weighted-average number of common shares outstanding (in shares)									351.3	350.2	347.3
Dilutive effect of stock options, RSUs and other (in shares)									0.0	1.6	0.0
Diluted weighted-average number of common shares outstanding (in shares)									351.3	351.8	347.3
(Loss) earnings per share attributable to Bausch Health Companies Inc.
Basic (in dollars per share)	$ (0.98)	$ (1.00)	$ (2.49)	$ (7.36)	$ 1.46	$ 3.71	$ (0.11)	$ 1.80	$ (11.81)	$ 6.86	$ (6.94)
Diluted (in dollars per share)	$ (0.98)	$ (1.00)	$ (2.49)	$ (7.36)	$ 1.45	$ 3.69	$ (0.11)	$ 1.79	$ (11.81)	$ 6.83	$ (6.94)