XML 155 R116.htm IDEA: XBRL DOCUMENT v3.21.1
Related party disclosures - Additional Information (Detail)
€ in Millions
12 Months Ended
Dec. 31, 2020
EUR (€)
shares
Dec. 31, 2019
EUR (€)
shares
Dec. 31, 2018
shares
Dec. 31, 2017
shares
Disclosure of transactions between related parties [line items]        
Accrued of key management compensation | € € 0.0 € 0.7    
Number of share options outstanding   103,469 74,401 31,880
ARYA [Member]        
Disclosure of transactions between related parties [line items]        
Number of Converted Stock Options In The Entity 417,415      
Number of matching stock option in the entity 750,076      
Service Options [Member] | Immatics GmbH [Member]        
Disclosure of transactions between related parties [line items]        
Number of share options outstanding 1,680,000      
Performance Based Options [Member] | Immatics GmbH [Member]        
Disclosure of transactions between related parties [line items]        
Number of share options outstanding 539,000      
Twenty Twenty Incentive Plan [Member] | Service Options [Member]        
Disclosure of transactions between related parties [line items]        
Percentage of stock vested over the period of four-year time-based vesting schedule 25.00%      
Twenty Twenty Incentive Plan [Member] | Performance Based Options [Member]        
Disclosure of transactions between related parties [line items]        
Percentage of stock vested over the period of four-year time-based vesting schedule 25.00%      
Key management personnel of entity or parent [member]        
Disclosure of transactions between related parties [line items]        
Payment of Payroll Tax of the employees | € € 3.4