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 Earnings Attributable to BMS	$ (1,056)	$ 1,353	$ 1,432	$ 1,710	$ 1,160	$ 1,901	$ 373	$ 1,486	$ 3,439	$ 4,920	$ 1,007
Weighted-average common shares outstanding - basic									1,705	1,633	1,645
Incremental shares attributable to share-based compensation plans									7	4	7
Weighted-average common shares outstanding - diluted									1,712	1,637	1,652
Earnings per Share - Basic	$ (0.55)	$ 0.83	$ 0.88	$ 1.05	$ 0.71	$ 1.16	$ 0.23	$ 0.91	$ 2.02	$ 3.01	$ 0.61
Earnings per Share - Diluted	$ (0.55)	$ 0.83	$ 0.87	$ 1.04	$ 0.71	$ 1.16	$ 0.23	$ 0.91	$ 2.01	$ 3.01	$ 0.61