Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended								6 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	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 3,039	$ 2,851	$ 2,834	$ 2,638	$ 2,833	$ 2,761	$ 2,813	$ 2,692	$ 5,472	$ 5,505	$ 11,362	$ 11,099	$ 10,584
Cost of sales			1,681	1,558	1,650		1,590	1,571	3,239	3,161	6,601	6,340	6,110
Gross margin	1,298	1,230	1,153	1,080	1,183	1,232	1,223	1,121	2,233	2,344	4,761	4,759	4,474
Selling, general and administrative expenses			641	601	627		676	633	1,242	1,309	2,535	2,620	2,627
Research and development expenses			166	129	175		172	141	295	313	595	654	615
Other operating income (expense), net											141	99	56
Operating income			350	383	391		377	434	733	811	1,772	1,584	1,288
Interest expense, net			20	18	11		11	12	38	23	71	45	55
Other (income) expense, net			4	(21)	(33)		(38)	(6)	(17)	(44)	731	(78)	133
Income from continuing operations before income taxes			326	386	413		404	428	712	832	970	1,617	1,100
Income tax expense (benefit)			(13)	(44)	(102)		(63)	(46)	(57)	(109)	41	(65)	(491)
Income from continuing operations			313	342	311		341	382	655	723	1,011	1,552	609
Loss from discontinued operations, net of tax					(6)	0	0	0		0	0	(6)	(7)
Net income			313	342	305		341	382	655	723	1,011	1,546	602
Less: Net income attributable to noncontrolling interests											10	0	0
Net income attributable to Baxter stockholders	$ (23)	$ 369	$ 313	$ 342	$ 305	$ 518	$ 341	$ 382	$ 655	$ 723	$ 1,001	$ 1,546	$ 602
Earnings per share from continuing operations
Basic (in dollars per share)					$ 0.59	$ 0.97	$ 0.64	$ 0.71		$ 1.35	$ 1.97	$ 2.91	$ 1.12
Diluted (in dollars per share)					0.58	0.95	0.62	0.69		1.32	1.93	2.84	1.10
Loss per share from discontinued operations
Basic (in dollars per share)					(0.01)	0	0	0		0	0	(0.01)	(0.01)
Diluted (in dollars per share)					(0.01)	0	0	0		0	0	(0.01)	(0.02)
Earnings per share
Basic (in dollars per share)	$ (0.05)	$ 0.72	$ 0.61	$ 0.67	0.58	0.97	0.64	0.71	$ 1.28	1.35	1.97	2.90	1.11
Diluted (in dollars per share)	$ (0.05)	$ 0.71	$ 0.60	$ 0.66	$ 0.57	$ 0.95	$ 0.62	$ 0.69	$ 1.26	$ 1.32	$ 1.93	$ 2.83	$ 1.08
Weighted-average number of shares outstanding
Basic (in shares)			510	512	528		535	539	511	537	509	534	543
Diluted (in shares)			519	522	538		547	551	520	549	519	546	555