Annual report pursuant to Section 13 and 15(d)

Note 19 - Employee Benefit Plans (Details Textual)

v3.20.4
Note 19 - Employee Benefit Plans (Details Textual)
shares in Thousands, $ in Millions
 12 Months Ended
Dec. 31, 2020
USD ($)
shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
May 05, 2016
shares
Deferred Compensation Arrangement with Individual, Percentage of Salary, Maximum Defer 75.00%      
Deferred Compensation Plan Assets $ 44 $ 39    
Deferred Compensation Arrangement, Compensation Expense $ 1 1 $ 1  
Huntsman Corporation 2016 Stock Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | shares       8,200
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) | shares 7,000      
Huntsman Corporation Stock Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) | shares       0
UNITED STATES        
Defined Contribution Plan, Cost $ 17 17 16  
Foreign Plan [Member]        
Defined Contribution Plan, Cost $ 3 4 4  
Money Purchase Pension Plan [Member] | UNITED STATES        
Defined Contribution Plan, Employer Non-discretionary Contribution, Percent 8.00%      
Huntsman UK Pension Plan [Member] | UNITED KINGDOM        
Transition Period for Defined Contributions (Year) 5 years      
Maximum [Member] | Salary Deferral Plan for New Hires [Member] | UNITED STATES        
Defined Contribution Plan, Employer Non-discretionary Contribution, Percent 6.00%      
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 4.00%      
Defined Contribution Plan, Employer Contribution, Percent of Employees' Gross Pay 10.00%      
Maximum [Member] | Salary Deferral Plan [Member] | UNITED STATES        
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 4.00%      
Maximum [Member] | Huntsman UK Pension Plan [Member] | UNITED KINGDOM        
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 15.00%      
Maximum [Member] | Huntsman UK Pension Plan, New Hires [Member] | UNITED KINGDOM        
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 12.00%      
Pension Plan [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 3,100 2,800    
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate and Other [Member]        
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Assets Transferred into (out of) Level 3 11 0    
Defined Benefit Plan, Plan Assets, Amount, Ending Balance 138 124 121  
Pension Plan [Member] | UNITED STATES        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 866 $ 790 $ 697  
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets 7.52% 7.52% 7.52%  
Pension Plan [Member] | UNITED STATES | Real Estate and Other [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 62 $ 67    
Pension Plan [Member] | UNITED STATES | Fair Value, Inputs, Level 3 [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance 62 67    
Pension Plan [Member] | UNITED STATES | Fair Value, Inputs, Level 3 [Member] | Real Estate and Other [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance 62 67    
Pension Plan [Member] | Foreign Plan [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 2,225 $ 1,960 $ 1,751  
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets 5.89% 5.89% 5.88%  
Pension Plan [Member] | Foreign Plan [Member] | Real Estate and Other [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 628 $ 505    
Pension Plan [Member] | Foreign Plan [Member] | Fair Value, Inputs, Level 3 [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance 76 57    
Pension Plan [Member] | Foreign Plan [Member] | Fair Value, Inputs, Level 3 [Member] | Real Estate and Other [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 76 57    
Pension Plan [Member] | Minimum [Member]        
Defined Benefit Plan, Cash Balance, Plan Annual Pay Credits, Percentage of Eligible Pay 6.00%      
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets 5.68%      
Pension Plan [Member] | Maximum [Member]        
Defined Benefit Plan, Cash Balance, Plan Annual Pay Credits, Percentage of Eligible Pay 12.00%      
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets 7.53%      
Other Postretirement Benefits Plan [Member]        
Number Of Fully Insured Medicare Part D Plans 2      
Other Postretirement Benefits Plan [Member] | UNITED STATES        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 0 0 $ 0  
Other Postretirement Benefits Plan [Member] | Foreign Plan [Member]        
Defined Benefit Plan, Plan Assets, Amount, Ending Balance $ 0 $ 0 $ 0