Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||||||
| Property, plant and equipment [abstract] | ||||||
| Property, plant and equipment |
667,059,000
EUR
|
604,711,000
EUR
|
664,644,000
EUR
|
600,532,000
EUR
|
— | — |
| Intangible assets and goodwill [abstract] | ||||||
| Intangible assets and goodwill |
220,116,000
EUR
|
180,251,000
EUR
|
190,033,000
EUR
|
141,451,000
EUR
|
— | — |
| Investment property [abstract] | ||||||
| Investment property |
4,545,000
EUR
|
7,641,000
EUR
|
1,258,000
EUR
|
4,230,000
EUR
|
— | — |
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements [abstract] | ||||||
| Investments in subsidiaries reported in separate financial statements |
0
EUR
|
38,276,000
EUR
|
0
EUR
|
37,001,000
EUR
|
— | — |
| Trade and other non-current receivables [abstract] | ||||||
| Other non-current receivables |
18,300,000
EUR
|
18,294,000
EUR
|
17,081,000
EUR
|
17,639,000
EUR
|
— | — |
| Non-current prepayments and non-current accrued income including non-current contract assets [abstract] | ||||||
| Non-current accrued income including non-current contract assets [abstract] | ||||||
| Non-current contract assets |
2,854,000
EUR
|
2,469,000
EUR
|
2,668,000
EUR
|
2,337,000
EUR
|
— | — |
| Trade and other current receivables [abstract] | ||||||
| Trade and other current receivables |
156,152,000
EUR
|
148,378,000
EUR
|
162,936,000
EUR
|
159,360,000
EUR
|
— | — |
| Current prepayments and current accrued income including current contract assets [abstract] | ||||||
| Current accrued income including current contract assets [abstract] | ||||||
| Current contract assets |
17,263,000
EUR
|
17,167,000
EUR
|
23,527,000
EUR
|
23,263,000
EUR
|
— | — |
| Classes of current inventories [abstract] | ||||||
| Current inventories |
22,478,000
EUR
|
19,603,000
EUR
|
26,175,000
EUR
|
21,811,000
EUR
|
— | — |
| Classes of current inventories, alternative [abstract] | ||||||
| Cash and cash equivalents [abstract] | ||||||
| Cash and cash equivalents |
15,935,000
EUR
|
3,754,000
EUR
|
8,167,000
EUR
|
2,086,000
EUR
|
1,153,000
EUR
|
13,219,000
EUR
|
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | ||||||
| Non-current assets or disposal groups classified as held for sale |
799,000
EUR
|
799,000
EUR
|
214,000
EUR
|
214,000
EUR
|
— | — |
| Miscellaneous current assets [abstract] | ||||||
| Current investments |
740,000
EUR
|
12,177,000
EUR
|
512,000
EUR
|
17,414,000
EUR
|
— | — |
| Borrowings [abstract] | ||||||
| Non-current portion of non-current borrowings |
309,023,000
EUR
|
309,023,000
EUR
|
184,221,000
EUR
|
184,221,000
EUR
|
— | — |
| Current borrowings and current portion of non-current borrowings [abstract] | ||||||
| Current borrowings and current portion of non-current borrowings |
40,015,000
EUR
|
41,415,000
EUR
|
32,080,000
EUR
|
45,095,000
EUR
|
— | — |
| Non-current portion of non-current borrowings, by type [abstract] | ||||||
| Current borrowings and current portion of non-current borrowings, by type [abstract] | ||||||
| Trade and other non-current payables [abstract] | ||||||
| Non-current accruals and non-current deferred income including non-current contract liabilities [abstract] | ||||||
| Non-current deferred income including non-current contract liabilities [abstract] | ||||||
| Non-current contract liabilities [abstract] | ||||||
| Non-current contract liabilities |
14,278,000
EUR
|
13,752,000
EUR
|
14,955,000
EUR
|
14,301,000
EUR
|
— | — |
| Accruals classified as non-current |
891,000
EUR
|
713,000
EUR
|
817,000
EUR
|
673,000
EUR
|
— | — |
| Other non-current payables |
18,455,000
EUR
|
12,281,000
EUR
|
38,896,000
EUR
|
20,856,000
EUR
|
— | — |
| Trade and other current payables [abstract] | ||||||
| Current accruals and current deferred income including current contract liabilities [abstract] | ||||||
| Current deferred income including current contract liabilities [abstract] | ||||||
| Current contract liabilities [abstract] | ||||||
| Current contract liabilities |
12,318,000
EUR
|
8,452,000
EUR
|
12,656,000
EUR
|
8,707,000
EUR
|
— | — |
| Accruals classified as current |
28,786,000
EUR
|
26,463,000
EUR
|
41,857,000
EUR
|
40,521,000
EUR
|
— | — |
| Trade and other current payables |
130,955,000
EUR
|
116,381,000
EUR
|
119,058,000
EUR
|
109,755,000
EUR
|
— | — |
| Issued capital [abstract] | ||||||
| Issued capital |
272,721,000
EUR
|
272,721,000
EUR
|
272,721,000
EUR
|
272,721,000
EUR
|
— | — |
| Retained earnings [abstract] | ||||||
| Retained earnings |
41,938,000
EUR
|
55,515,000
EUR
|
33,305,000
EUR
|
50,359,000
EUR
|
— | — |
| Accumulated other comprehensive income [abstract] | ||||||
| Reserve of exchange differences on translation |
9,000
EUR
|
0
EUR
|
25,000
EUR
|
0
EUR
|
— | — |
| Reserve of remeasurements of defined benefit plans |
2,139,000
EUR
|
1,863,000
EUR
|
2,988,000
EUR
|
2,733,000
EUR
|
— | — |
| Miscellaneous equity [abstract] | ||||||
| Statutory reserve |
54,854,000
EUR
|
54,544,000
EUR
|
54,854,000
EUR
|
54,544,000
EUR
|
— | — |
| Capital reserve |
181,489,000
EUR
|
180,956,000
EUR
|
181,489,000
EUR
|
180,956,000
EUR
|
— | — |
| Net assets (liabilities) [abstract] | ||||||
| Assets |
1,250,339,000
EUR
|
1,237,941,000
EUR
|
1,227,839,000
EUR
|
1,226,566,000
EUR
|
— | — |
| Liabilities |
649,908,000
EUR
|
625,700,000
EUR
|
637,355,000
EUR
|
620,782,000
EUR
|
— | — |
| Net current assets (liabilities) [abstract] | ||||||
| Current assets |
217,133,000
EUR
|
205,028,000
EUR
|
225,781,000
EUR
|
227,912,000
EUR
|
— | — |
| Current liabilities |
225,304,000
EUR
|
207,213,000
EUR
|
317,160,000
EUR
|
316,975,000
EUR
|
— | — |
| Assets less current liabilities [abstract] |