EQUITY (Changes in Equity) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Common Stock, Dividends, Per Share, Declared	$ 0.41	$ 0.41	$ 0.41	$ 0.40	$ 0.40	$ 0.40	$ 0.41	$ 0.40
Stock Repurchased During Period, Value	$ 300
Stock Repurchase Program, Remaining Authorized Repurchase Amount	1,000						$ 1,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Value, Issued, Balance at Beginning of Period			$ 221				221
Common Stock, Value, Issued, Balance at End of Period	221						221
Capital in Excess of Par Value of Stock, Balance at Beginning of Period			2,081				2,081
Capital in Excess of Par Value of Stock, Balance at End of Period	2,206						2,206
Accumulated Other Comprehensive Loss, Balance at Beginning of Period			(2,762)				(2,762)
Other Comprehensive Income/(Loss)	1,158			$ 8			1,299	$ (3)
Accumulated Other Comprehensive Loss, Balance at End of Period	(1,463)						(1,463)
Retained Earnings, Balance at Beginning of Period			34,065				34,065
Net Earnings Attributable to BMS	1,353			1,901			4,495	3,760
Retained Earnings, Balance at End of Period	$ 36,555						36,555
Stock repurchase program, Shares	6.5
Cost of Treasury Stock, Balance at Beginning of Period			(19,574)				(19,574)
Cost of Treasury Stock, Balance at End of Period	$ (19,871)						(19,871)
Noncontrolling interest, Balance at Beginning of Period			$ 96				96
Net Income (Loss) Attributable to Noncontrolling Interest	(13)			$ (11)			(25)	$ (29)
Noncontrolling interest, Balance at End of Period	$ 106						$ 106
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares Issued, Balance at Beginning of Period	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0
Common Stock, Shares Issued, Balance at End of Period	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0	2,208.0
Common Stock, Value, Issued, Balance at Beginning of Period	$ 221	$ 221	$ 221	$ 221	$ 221	$ 221	$ 221	$ 221
Common Stock, Value, Issued, Balance at End of Period	221	221	221	221	221	221	221	221
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	2,150	2,103	2,081	1,966	1,916	1,898	2,081	1,898
Stockholders' Equity, Other	56	47	22	63	50	18
Capital in Excess of Par Value of Stock, Balance at End of Period	2,206	2,150	2,103	2,029	1,966	1,916	2,206	2,029
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	(2,621)	(2,644)	(2,762)	(2,334)	(2,234)	(2,289)	(2,762)	(2,289)
Cumulative effect of an accounting change on retained earnings												$ (34)
Retained Earnings, Adjusted balance at Beginning of Period											$ (2,762)		$ (2,323)
Other Comprehensive Income/(Loss)	1,158	23	118	8	(100)	89
Accumulated Other Comprehensive Loss, Balance at End of Period	(1,463)	(2,621)	(2,644)	(2,326)	(2,334)	(2,234)	(1,463)	(2,326)
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of an accounting change on retained earnings										$ 5		$ 332
Retained Earnings, Adjusted balance at Beginning of Period											$ 34,070		$ 31,492
Retained Earnings, Balance at Beginning of Period	35,870	35,109	34,065	32,044	32,323	31,160	34,065	31,160
Net Earnings Attributable to BMS	1,353	1,432	1,710	1,901	373	1,486
Cash dividends declared	(668)	(671)	(671)	(653)	(652)	(655)
Retained Earnings, Balance at End of Period	$ 36,555	$ 35,870	$ 35,109	$ 33,292	$ 32,044	$ 32,323	$ 36,555	$ 33,292
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Shares, Acquired	7.0				2.0	3.0
Treasury Stock, Shares, Balance at Beginning of Period	572.0	572.0	576.0	576.0	574.0	575.0	576.0	575.0
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	0.0	0.0	(4.0)	0.0	0.0	(4.0)
Treasury Stock, Shares, Balance at End of Period	579.0	572.0	572.0	576.0	576.0	574.0	579.0	576.0
Cost of Treasury Stock, Balance at Beginning of Period	$ (19,571)	$ (19,571)	$ (19,574)	$ (19,580)	$ (19,433)	$ (19,249)	$ (19,574)	$ (19,249)
Stock repurchase program, Cost	(300)				(147)	(166)
Employee stock compensation plans, Cost	0	0	3	4	0	(18)
Cost of Treasury Stock, Balance at End of Period	(19,871)	(19,571)	(19,571)	(19,576)	(19,580)	(19,433)	(19,871)	(19,576)
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interest, Balance at Beginning of Period	102	99	96	101	113	106	96	106
Net Income (Loss) Attributable to Noncontrolling Interest	13	7	5	11	9	9
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(9)	(4)	(2)	(2)	(21)	(2)
Noncontrolling interest, Balance at End of Period	$ 106	$ 102	$ 99	$ 110	$ 101	$ 113	$ 106	$ 110
Forecast [Member]
Stock Repurchase Program, Authorized Amount									$ 7,000