Related party transactions (Details) - SEK (kr) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Joint Venture Polar Charge A Band Its Subsidiaries [Member] | ||
| IfrsStatementLineItems [Line Items] | ||
| Sales to related party | kr (907) | kr 35,846 |
| Purchases from related party | 7,058 | 5,943 |
| Amounts owed by related party | 213 | 1,904 |
| Amounts owed to related party | 122 | 1,848 |
| Right-of-use asset | 99,132 | 95,065 |
| Lease liability | 107,205 | 100,274 |
| Board Members Board Fees [Member] | ||
| IfrsStatementLineItems [Line Items] | ||
| Sales to related party | ||
| Purchases from related party | 1,315 | 946 |
| Amounts owed by related party | ||
| Amounts owed to related party | 23 | |
| Right-of-use asset | ||
| Lease liability | ||
| Board Members Consultancy [Member] | ||
| IfrsStatementLineItems [Line Items] | ||
| Sales to related party | ||
| Purchases from related party | 6,663 | 249 |
| Amounts owed by related party | ||
| Amounts owed to related party | ||
| Right-of-use asset | ||
| Lease liability | ||