Statement Of Changes In Equity [Abstract]

SES FDR - Filing #887069

Concept	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Increase (decrease) through appropriation of retained earnings, equity	– EUR	– EUR	86,000,000 EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR	86,000,000 EUR	– EUR	– EUR	296,000,000 EUR	296,000,000 EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR
Increase (decrease) through exercise of options, equity	– EUR	6,000,000 EUR	6,000,000 EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR	7,000,000 EUR	7,000,000 EUR	– EUR	14,000,000 EUR	– EUR	– EUR	– EUR	– EUR	– EUR	7,000,000 EUR
Purchase of treasury shares	– EUR	119,000,000 EUR	– EUR	119,000,000 EUR	– EUR	– EUR	– EUR	– EUR	119,000,000 EUR	– EUR	10,000,000 EUR	10,000,000 EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR	10,000,000 EUR
Sale or issue of treasury shares	—	—	—	—	—	—	—	—	—	—	17,000,000 EUR	17,000,000 EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR	– EUR	17,000,000 EUR