v3.26.1
Borrowings - Schedule of Interest Bearing Borrowings (Detail) - EUR (€)
€ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 5,507 € 4,247
Amounts outstanding, carried at amortised cost, Current 798 273
Current [member]    
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Current 798 273
Non-Current [member]    
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 5,507 € 4,247
Euro Private Placement 2027 (EUR 140 million under EMTN) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 4.00% 4.00%
Maturity May 2027 May 2027
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 140 € 140
Eurobond 2027 (EUR 500 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 0.875% 0.875%
Maturity November 2027 November 2027
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 499 € 499
Eurobond 2028 (EUR 400 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 2.00% 2.00%
Maturity July 2028 July 2028
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 398 € 398
Eurobond 2029 (EUR 750 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 3.50% 3.50%
Maturity January 2029 January 2029
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 748 € 746
Eurobond 2030 (EUR 500 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 4.125%  
Maturity June 2030  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 497  
Eurobond 2033 (EUR 500 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 4.875%  
Maturity June 2033  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 496  
Fixed Term Loan (LuxGovSat), non-listed [member] | Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 3.30%  
Maturity December 2027 December 2027
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Current € 16 € 17
Fixed Term Loan (LuxGovSat), non-listed [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 3.30% 3.30%
Maturity December 2027 December 2027
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 16 € 32
German bond (EUR 50 million), non-listed [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 4.00% 4.00%
Maturity November 2032 November 2032
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 50 € 50
US Bond (USD 250 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 5.30% 5.30%
Maturity April 2043 April 2043
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 208 € 235
US Bond (USD 500 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 5.30% 5.30%
Maturity March 2044 March 2044
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 414 € 468
Hybrid Bond NC5.25 (EUR 500 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 5.50%  
Maturity September 2054  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 495 494
Hybrid Bond NC8 (EUR 500 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 6.00%  
Maturity September 2054  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 496 € 496
Floating Term Loan with European Investment Bank (EUR 300 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 0.867%  
Borrowings, interest rate basis EURIBOR 6M + 0.867  
Maturity June 2032  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 300  
Term Loan Agreement (USD 1,000 million) [member] | Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 2.125%  
Borrowings, interest rate basis SOFR 3M + 2.125  
Maturity June 2029  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Current € 124  
Term Loan Agreement (USD 1,000 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 2.125%  
Borrowings, interest rate basis SOFR 3M + 2.125  
Maturity June 2029  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 711  
Fixed Term Loan (SES Astra 1P Sarl), non-listed [member] | Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 3.15% 3.15%
Maturity March 2031 March 2031
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Current € 8 € 6
Fixed Term Loan (SES Astra 1P Sarl), non-listed [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 3.15%  
Maturity March 2031  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 19 28
Floating Term Loan Facility (SES Satellites Ventures Sarl), non-listed [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 2.20%  
Borrowings, interest rate basis SOFR 3M + 2.2  
Maturity March 2030  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current € 20 € 10
Eurobond 2026 (EUR 650 million) [member] | Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate 1.625%  
Maturity March 2026  
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Current € 650  
Eurobond 2026 (EUR 650 million) [member] | Non-Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate   1.625%
Maturity   March 2026
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Non-current   € 651
German bond (EUR 250 million) [member] | Current [member]    
Disclosure of detailed information about borrowings [line items]    
Effective interest rate   1.71%
Maturity   December 2025
Amounts outstanding, carried at amortised cost, Non-current and Current    
Amounts outstanding, carried at amortised cost, Current   € 250