Analysis Of Income And Expense [Abstract]

Alten - Filing #2816643

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	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
Analysis of income and expense [abstract]
Material income and expense [abstract]
Other finance income	—	—	—	—	—	—	—	13 718 EUR	—	32 601 EUR	—	—	—	—	—	—
Other finance cost	—	—	—	—	—	—	—	12 460 EUR	—	16 173 EUR	—	—	—	—	—	—
Expenses by nature [abstract]
Classes of employee benefits expense [abstract]
Expense from share-based payment transactions with employees	—	—	—	—	—	—	—	21 929 EUR	—	7 902 EUR	—	—	—	—	—	—
Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss [abstract]
Depreciation and amortisation expense [abstract]
Depreciation and amortisation expense	—	—	—	—	—	—	—	72 469 EUR	—	66 555 EUR	—	—	—	—	—	—
Tax expense other than income tax expense	—	—	—	—	—	—	—	13 081 EUR	—	11 336 EUR	—	—	—	—	—	—
Other expenses, by nature	—	—	—	—	—	—	—	182 802 EUR	—	157 863 EUR	—	—	—	—	—	—
Disclosure of attribution of expenses by nature to their function [text block]	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
Disclosure of attribution of expenses by nature to their function [abstract]
Disclosure of attribution of expenses by nature to their function [line items]
Miscellaneous other comprehensive income [abstract]
Other comprehensive income, net of tax, exchange differences on translation of foreign operations and hedges of net investments in foreign operations [abstract]
Other comprehensive income, net of tax, exchange differences on translation of foreign operations	—	—	—	—	—	—	—	21 185 EUR	—	16 425 EUR	—	—	—	—	—	—
Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract]
Share of profit (loss) of associates accounted for using equity method	—	—	—	—	—	—	—	62,000 EUR	—	1 420 EUR	—	—	—	—	—	—
Comprehensive income, continuing and discontinued operations [abstract]
Comprehensive income	5 080 EUR	49,000 EUR	207 837 EUR	4,000 EUR	21 188 EUR	223 945 EUR	53,000 EUR	223 994 EUR	98 011 EUR	92 940 EUR	16 436 EUR	12,000 EUR	224,000 EUR	213,000 EUR	93 154 EUR	11 580 EUR
Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract]
Comprehensive income, attributable to owners of parent	—	—	—	—	—	—	—	223 945 EUR	—	93 154 EUR	—	—	—	—	—	—
Comprehensive income attributable to non-controlling interests, continuing and discontinued operations [abstract]
Comprehensive income, attributable to non-controlling interests	—	—	—	—	—	—	—	49,000 EUR	—	213,000 EUR	—	—	—	—	—	—