| Document and Entity Information | Sep. 01, 2021 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | BAXTER INTERNATIONAL INC |
| Amendment Flag | false |
| Entity Central Index Key | 0000010456 |
| Document Type | 8-K |
| Document Period End Date | Sep. 1, 2021 |
| Entity Incorporation State 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 |
| Common Stock 100 Per Value [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Stock, $1.00 par value |
| Trading Symbol | BAX (NYSE) |
| Security Exchange Name | NYSE |
| M 0 [Member] | |
| Document And Entity Information [Line Items] | |
| Security Exchange Name | CHX |
| Global Notes 13 Due 2025 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 1.3% Global Notes due 2025 |
| Trading Symbol | BAX 25 |
| Security Exchange Name | NYSE |
| Global Notes 13 Due 2029 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 1.3% Global Notes due 2029 |
| Trading Symbol | BAX 29 |
| Security Exchange Name | NYSE |
| Global Notes 04 Due 2024 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 0.4% Global Notes due 2024 |
| Trading Symbol | BAX 24 |
| Security Exchange Name | NYSE |
| Global Notes 395 Due 2030 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 3.95% Global Notes due 2030 |
| Trading Symbol | BAX 30 |
| Security Exchange Name | NYSE |
| Global Notes 173 Due 2031 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 1.73% Global Notes due 2031 |
| Trading Symbol | BAX 31 |
| Security Exchange Name | NYSE |
