Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 29, 2020	Jun. 28, 2019
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-4448
Entity Registrant Name	Baxter International Inc.
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 Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
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 Public Float			$ 42
Entity Common Stock, Shares Outstanding		507,263,731
Documents Incorporated by Reference	Portions of the registrant’s definitive 2020 proxy statement for use in connection with its Annual Meeting of Stockholders expected to be held on May 5, 2020 are incorporated by reference into Part III of this report.
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0000010456
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Fiscal Year Focus	2019
CHICAGO STOCK EXCHANGE, INC. | Common Stock, $1.00 per Value [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common stock, $1.00 par value
Trading Symbol	BAX (NYSE)
Security Exchange Name	CHX
NEW YORK STOCK EXCHANGE, INC. | Common Stock, $1.00 per Value [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common stock, $1.00 par value
Trading Symbol	BAX (NYSE)
Security Exchange Name	NYSE
NEW YORK STOCK EXCHANGE, INC. | Global Notes 0.4% due 2024 [Member]
Entity Information [Line Items]
Title of 12(b) Security	0.4% Global Notes due 2024
Trading Symbol	BAX 24
Security Exchange Name	NYSE
NEW YORK STOCK EXCHANGE, INC. | Global Notes 1.3% due 2025 [Member]
Entity Information [Line Items]
Title of 12(b) Security	1.3% Global Notes due 2025
Trading Symbol	BAX 25
Security Exchange Name	NYSE
NEW YORK STOCK EXCHANGE, INC. | Global Notes 1.3% due 2029 [Member]
Entity Information [Line Items]
Title of 12(b) Security	1.3% Global Notes due 2029
Trading Symbol	BAX 29
Security Exchange Name	NYSE