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 Earnings Attributable to BMS	$ 1,160	$ 1,901	$ 373	$ 1,486	$ (2,328)	$ 845	$ 916	$ 1,574	$ 4,920	$ 1,007	$ 4,457
Weighted-average common shares outstanding - basic									1,633	1,645	1,671
Incremental shares attributable to share-based compensation plans									4	7	9
Weighted-average common shares outstanding - diluted									1,637	1,652	1,680
Earnings per Share - Basic	$ 0.71	$ 1.16	$ 0.23	$ 0.91	$ (1.42)	$ 0.52	$ 0.56	$ 0.95	$ 3.01	$ 0.61	$ 2.67
Earnings per Share - Diluted	$ 0.71	$ 1.16	$ 0.23	$ 0.91	$ (1.42)	$ 0.51	$ 0.56	$ 0.94	$ 3.01	$ 0.61	$ 2.65