| Document and Entity Information | Feb. 21, 2020 |
| Document And Entity Information [Line Items] | |
| Entity Central Index Key | 0000010456 |
| Amendment Flag | false |
| Document Type | 8-K |
| Document Period End Date | Feb. 21, 2020 |
| Entity Registrant Name | Baxter International Inc |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-4448 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| 1.30% Senior Notes due May 2025 | |
| Document And Entity Information [Line Items] | |
| Trading Symbol | BAX 25 |
| Title of 12(b) Security | 1.3% Global Notes due 2025 |
| Security Exchange Name | NYSE |
| 1.3% Senior Notes Due in May 2029 | |
| Document And Entity Information [Line Items] | |
| Trading Symbol | BAX 29 |
| Title of 12(b) Security | 1.3% Global Notes due 2029 |
| Security Exchange Name | NYSE |
| 0.4% Senior Notes Due in May 2024 | |
| Document And Entity Information [Line Items] | |
| Trading Symbol | BAX 24 |
| Title of 12(b) Security | 0.4% Global Notes due 2024 |
| Security Exchange Name | NYSE |
| New York Stock Exchange | Common Stock | |
| Document And Entity Information [Line Items] | |
| Trading Symbol | BAX |
| Title of 12(b) Security | Common Stock, $1.00 par value |
| Security Exchange Name | NYSE |
| Chicago Stock Exchange | Common Stock | |
| Document And Entity Information [Line Items] | |
| No Trading Symbol Flag | true |
| Title of 12(b) Security | Common Stock, $1.00 par value |
| Security Exchange Name | CHX |
