Statement Of Cash Flows [Abstract]
| Concept | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||||
| Cash flows from (used in) operating activities [abstract] | |||||||
| Profit (loss) | 
                                                71 879
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | 
                                                71 879
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
                                                125 774
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | 
                                                125 774
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | 
| Adjustments to reconcile profit (loss) [abstract] | |||||||
| Adjustments for depreciation and amortisation expense | 
                                                55 250
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                112 810
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Adjustments for provisions | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                116,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) operations | 
                                                21 573
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                21 082
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Interest paid, classified as operating activities | 
                                                2 855
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                2 446
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid (refund), classified as operating activities | 
                                                37,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                3 905
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Other inflows (outflows) of cash, classified as operating activities | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                683,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) operating activities | 
                                                19 546
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                13 495
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) investing activities [abstract] | |||||||
| Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                3 000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Purchase of property, plant and equipment, classified as investing activities | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Purchase of other long-term assets, classified as investing activities | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                116,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) investing activities | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                3 116
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) financing activities [abstract] | |||||||
| Proceeds from issuing shares | 
                                                51 318
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Payments of other equity instruments | 
                                                4 082
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Proceeds from borrowings, classified as financing activities | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                20 000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Repayments of borrowings, classified as financing activities | 
                                                2 083
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                -
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Payments of lease liabilities, classified as financing activities | 
                                                4 908
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                4 707
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Cash flows from (used in) financing activities | 
                                                32 236
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                12 223
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||||
| Effect of exchange rate changes on cash and cash equivalents | 
                                                100,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                222,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in cash and cash equivalents after effect of exchange rate changes | 
                                                12 690
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                1 844
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                14 931
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | — | 
                                                2 341
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | 
                                                4 406
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             |