Note 3 - Business Combinations - Pro Forma Revenues and Net Income (Details) $ in Millions  | 
3 Months Ended | 
|---|---|
| 
 Mar. 31, 2021  
USD ($) 
 | |
| Revenues | $ 1,841 | 
| Net income | 88 | 
| Net income attributable to Huntsman Corporation | 71 | 
| Huntsman International LLC [Member] | |
| Revenues | 1,841 | 
| Net income | 90 | 
| Net income attributable to Huntsman Corporation | $ 73 | 
| X | ||||||||||
- Definition The pro forma net Income or Loss including noncontrolling interests for the period as if the business combination or combinations had been completed at the beginning of a period. No definition available. 
  | 
| X | ||||||||||
- Definition The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
  | 
| X | ||||||||||
- Definition The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
  | 
| X | ||||||||||
- Details 
  |