LOSS PER SHARE - Schedule of Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net loss attributable to Bausch Health Companies Inc.	$ (610)	$ (152)
Basic weighted-average common shares (in shares)	356.8	353.4
Diluted weighted-average common shares (in shares)	356.8	353.4
Basic loss per share attributable to Bausch Health Companies Inc. (in usd per share)	$ (1.71)	$ (0.43)
Diluted loss per share attributable to Bausch Health Companies Inc. (in usd per share)	$ (1.71)	$ (0.43)