EQUITY (Changes in Equity) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended					6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Common Stock, Dividends, Per Share, Declared	$ 0.49	$ 0.49	$ 0.45	$ 0.45
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 3,400.0					$ 3,400.0		$ 4,400.0
Stock Repurchase Program, Authorized Amount	2,000.0				$ 7,000.0	2,000.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Value, Issued, Balance at Beginning of Period		$ 292.0				292.0
Common Stock, Value, Issued, Balance at End of Period	292.0					292.0
Capital in Excess of Par Value of Stock, Balance at Beginning of Period		44,325.0				44,325.0
Capital in Excess of Par Value of Stock, Balance at End of Period	44,064.0					44,064.0
Accumulated Other Comprehensive Loss, Balance at Beginning of Period		(1,839.0)				(1,839.0)
Other Comprehensive Income/(Loss)	26.0		$ (7.0)			321.0	$ (36.0)
Accumulated Other Comprehensive Loss, Balance at End of Period	(1,518.0)					(1,518.0)
Retained Earnings, Balance at Beginning of Period		21,281.0				21,281.0
Net Earnings/(Loss) Attributable to BMS	1,055.0		(85.0)			3,076.0	(860.0)
Treasury Stock, Value, Acquired, Cost Method			1,400.0
Retained Earnings, Balance at End of Period	22,168.0					22,168.0
Cost of Treasury Stock, Balance at Beginning of Period		(26,237.0)				(26,237.0)
Cost of Treasury Stock, Balance at End of Period	(28,198.0)					(28,198.0)
Noncontrolling interest		$ 60.0				60.0
Noncontrolling Interest	(6.0)		$ (5.0)			(14.0)	$ (14.0)
Noncontrolling interest	$ 66.0					$ 66.0
Stock repurchase program, Shares			16.0	1.4	99.0	47.0
Stock Repurchased During Period, Value			$ 81.0			$ 3,000.0
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares Issued, Balance at Beginning of Period	2,923.0	2,923.0	2,923.0	2,923.0		2,923.0	2,923.0
Common Stock, Shares Issued, Balance at End of Period	2,923.0	2,923.0	2,923.0	2,923.0	2,923.0	2,923.0	2,923.0
Common Stock, Value, Issued, Balance at Beginning of Period	$ 292.0	$ 292.0	$ 292.0	$ 292.0		$ 292.0	$ 292.0
Common Stock, Value, Issued, Balance at End of Period	292.0	292.0	292.0	292.0	$ 292.0	292.0	292.0
Capital in Excess of Par Value of Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital in Excess of Par Value of Stock, Balance at Beginning of Period	43,852.0	44,325.0	43,254.0	43,709.0		44,325.0	43,709.0
Stock compensation	212.0	(473.0)	(210.0)	(455.0)
Capital in Excess of Par Value of Stock, Balance at End of Period	44,064.0	43,852.0	44,444.0	43,254.0	43,709.0	44,064.0	44,444.0
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	(1,544.0)	(1,839.0)	(1,549.0)	(1,520.0)		(1,839.0)	(1,520.0)
Other Comprehensive Income/(Loss)	26.0	295.0	(7.0)	(29.0)
Accumulated Other Comprehensive Loss, Balance at End of Period	(1,518.0)	(1,544.0)	(1,556.0)	(1,549.0)	(1,520.0)	(1,518.0)	(1,556.0)
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Retained Earnings, Balance at Beginning of Period	22,204.0	21,281.0	32,671.0	34,474.0		21,281.0	34,474.0
Net Earnings/(Loss) Attributable to BMS	1,055.0	2,021.0	(85.0)	(775.0)
Cash dividends declared	(1,091.0)	(1,098.0)	(1,021.0)	(1,028.0)
Retained Earnings, Balance at End of Period	$ 22,168.0	$ 22,204.0	$ 31,565.0	$ 32,671.0	$ 34,474.0	$ 22,168.0	$ 31,565.0
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Shares, Balance at Beginning of Period	692.0	679.0	660.0	672.0		679.0	672.0
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	(10.0)	(15.0)	(7.0)	(13.0)
Treasury Stock, Shares, Balance at End of Period	701.0	692.0	669.0	660.0	672.0	701.0	669.0
Cost of Treasury Stock, Balance at Beginning of Period	$ (27,199.0)	$ (26,237.0)	$ (24,757.0)	$ (25,357.0)		$ (26,237.0)	$ (25,357.0)
Employee stock compensation plans, Cost	236.0	806.0	506.0	681.0
Cost of Treasury Stock, Balance at End of Period	$ (28,198.0)	$ (27,199.0)	$ (25,651.0)	$ (24,757.0)	$ (25,357.0)	(28,198.0)	(25,651.0)
Stock repurchase program, Shares	19.0	28.0	16.0	1.0
Stock Repurchased During Period, Value	$ 1,235.0	$ 1,768.0	$ 1,400.0	$ 81.0
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interest	68.0	60.0	66.0	100.0		60.0	100.0
Noncontrolling Interest	6.0	8.0	5.0	9.0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(8.0)		(5.0)	(43.0)
Noncontrolling interest	$ 66.0	$ 68.0	$ 66.0	$ 66.0	$ 100.0	$ 66.0	$ 66.0