Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	Apr. 21, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	1-4448
Entity Registrant Name	BAXTER INTERNATIONAL INC.
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-0781620
Entity Address, Address Line One	One Baxter Parkway,
Entity Address, City or Town	Deerfield,
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60015
City Area Code	224.
Local Phone Number	948.2000
Entity Central Index Key	0000010456
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		508,836,225
Common Stock, $1.00 per Value | NEW YORK STOCK EXCHANGE, INC.
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $1.00 par value
Trading Symbol	BAX (NYSE)
Security Exchange Name	NYSE
Common Stock, $1.00 per Value | CHICAGO STOCK EXCHANGE, INC
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $1.00 par value
Trading Symbol	BAX (NYSE)
Security Exchange Name	CHX
0.4% Global Notes due 2024 | NEW YORK STOCK EXCHANGE, INC.
Document Information [Line Items]
Title of 12(b) Security	0.4% Global Notes due 2024
Trading Symbol	BAX 24
Security Exchange Name	NYSE
1.3% Global Notes due 2025 | NEW YORK STOCK EXCHANGE, INC.
Document Information [Line Items]
Title of 12(b) Security	1.3% Global Notes due 2025
Trading Symbol	BAX 25
Security Exchange Name	NYSE
1.3% Global Notes due 2029 | NEW YORK STOCK EXCHANGE, INC.
Document Information [Line Items]
Title of 12(b) Security	1.3% Global Notes due 2029
Trading Symbol	BAX 29
Security Exchange Name	NYSE