SUPPLEMENTARY DATA (UNAUDITED) - Schedule of Unaudited Quarterly Consolidated Financial Data (Details) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 2,121	$ 2,136	$ 2,128	$ 1,995	$ 2,163	$ 2,219	$ 2,233	$ 2,109	$ 8,380	$ 8,724	$ 9,674
Expenses	2,096	2,019	2,373	4,276	2,485	2,181	2,058	1,898	10,764	8,622	10,240
Operating (loss) income	25	117	(245)	(2,281)	(322)	38	175	211	(2,384)	102	(566)
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)
Earnings (loss) 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)
Net cash provided by operating activities	$ 319	$ 522	$ 222	$ 438	$ 578	$ 490	$ 268	$ 954	$ 1,501	$ 2,290	$ 2,087