EQUITY (Changes in Equity) (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	Jan. 01, 2019	Jan. 01, 2018	Jan. 01, 2017	Dec. 31, 2016
Equity [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.45	$ 0.41	$ 0.41	$ 0.41	$ 0.41	$ 0.40	$ 0.40	$ 0.40	$ 1.68	$ 1.61	$ 1.57
Common Stock, Value, Issued, Balance at January 1,				$ 221					$ 221
Common Stock, Value, Issued, Balance at December 31,	$ 292				$ 221				292	$ 221
Capital in Excess of Par Value of Stock, Balance at January 1,				2,081					2,081
Capital in Excess of Par Value of Stock, Balance at December 31,	43,709				2,081				43,709	2,081
Accumulated Other Comprehensive Loss, Balance at January 1				(2,762)					(2,762)
Other Comprehensive Income (Loss), Net of Tax									1,242	(156)	$ 214
Accumulated Other Comprehensive Loss, Balance at December 31	(1,520)				(2,762)				(1,520)	(2,762)
Retained Earnings, Balance at January 1,				34,065					34,065
Net Earnings/(Loss) Attributable to BMS	(1,056)	$ 1,353	$ 1,432	$ 1,710	1,160	$ 1,901	$ 373	$ 1,486	3,439	4,920	1,007
Retained Earnings, Balance at December 31,	$ 34,474				$ 34,065				$ 34,474	$ 34,065
Treasury Stock, Shares, Balance at January 1,				576					576
Treasury Stock, Shares, Balance at December 31,	672				576				672	576
Cost of Treasury Stock, Balance at January 1,				$ (19,574)					$ (19,574)
Cost of Treasury Stock, Balance at December 31,	$ (25,357)				$ (19,574)				(25,357)	$ (19,574)
Noncontrolling interest, Balance at January 1,				96					96
Net Income (Loss) Attributable to Noncontrolling Interest	(4)	$ 13	$ 7	$ 5	(2)	$ 11	$ 9	$ 9	21	27	$ (32)
Noncontrolling interest, Balance at December 31,	$ 100				$ 96				$ 100	$ 96
Document Period End Date									Dec. 31, 2019
Common Stock [Member]
Equity [Line Items]
Common Stock, Shares Issued, Balance at January 1,				2,208				2,208	2,208	2,208	2,208
Common Stock, Shares Issued, Balance at December 31,	2,923				2,208				2,923	2,208	2,208
Common Stock, Value, Issued, Balance at January 1,				$ 221				$ 221	$ 221	$ 221	$ 221
Common Stock, Value, Issued, Balance at December 31,	$ 292				$ 221				$ 292	221	221
Stock Issued During Period, Shares, New Issues									715
Stock Issued During Period, Value, New Issues									$ 71
Capital in Excess of Par Value of Stock [Member]
Equity [Line Items]
Capital in Excess of Par Value of Stock, Balance at January 1,				2,081				1,898	2,081	1,898	1,725
Capital in Excess of Par Value of Stock, Balance at December 31,	43,709				2,081				43,709	2,081	1,898
Stock compensation									307	183	173
Stock Issued During Period, Value, New Issues									42,721
Stock repurchase program, Cost of Treasury Stock									1,400
Accumulated Other Comprehensive Loss [Member]
Equity [Line Items]
Accumulated Other Comprehensive Loss, Balance at January 1				(2,762)				(2,289)	(2,762)	(2,289)	(2,503)
Other Comprehensive Income (Loss), Net of Tax									1,242	(156)	214
Accounting change - cumulative effect					(283)					(283)			$ (34)
Accumulated Other Comprehensive Loss, Balance at December 31	(1,520)				(2,762)				(1,520)	(2,762)	(2,289)
Retained Earnings, adjusted balance at January 1,					(2,762)					(2,762)	(2,323)				$ (2,503)
Retained Earnings [Member]
Equity [Line Items]
Accounting change - cumulative effect					283					283		$ 5	$ 332	$ (787)
Retained Earnings, Balance at January 1,				$ 34,065				$ 31,160	34,065	31,160	33,513
Net Earnings/(Loss) Attributable to BMS									3,439	4,920	1,007
Cash dividends declared									(3,035)	(2,630)	(2,573)
Retained Earnings, adjusted balance at January 1,					34,070					34,070	31,492				$ 32,726
Retained Earnings, Balance at December 31,	$ 34,474				$ 34,065				$ 34,474	$ 34,065	$ 31,160
Treasury Stock [Member]
Equity [Line Items]
Treasury Stock, Shares, Balance at January 1,				576				575	576	575	536
Stock repurchase program, Treasury Stock									105	5	44
Employee stock compensation plans, Shares									(9)	(4)	(5)
Treasury Stock, Shares, Balance at December 31,	672				576				672	576	575
Cost of Treasury Stock, Balance at January 1,				$ (19,574)				$ (19,249)	$ (19,574)	$ (19,249)	$ (16,779)
Stock repurchase program, Cost of Treasury Stock									(5,900)	(313)	(2,477)
Employee stock compensation plans, Cost									117	(12)	7
Cost of Treasury Stock, Balance at December 31,	$ (25,357)				$ (19,574)				(25,357)	(19,574)	(19,249)
Noncontrolling Interest [Member]
Equity [Line Items]
Noncontrolling interest, Balance at January 1,				$ 96				$ 106	96	106	170
Net Income (Loss) Attributable to Noncontrolling Interest									(21)	(27)	(27)
Noncontrolling Interest, Period Increase (Decrease)											(59)
Distributions									(17)	(37)	(32)
Noncontrolling interest, Balance at December 31,	$ 100				$ 96				$ 100	$ 96	$ 106