Statement Of Changes In Equity [Abstract]
| Concept |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | ||||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||||
| Equity |
5,515,000,000
SEK
|
5,324,000,000
SEK
|
9,000,000
SEK
|
— |
200,000,000
SEK
|
— | — | — |
4,303,000,000
SEK
|
4,132,000,000
SEK
|
— |
200,000,000
SEK
|
29,000,000
SEK
|
— |
3,182,000,000
SEK
|
48,000,000
SEK
|
3,430,000,000
SEK
|
200,000,000
SEK
|
| Changes in equity [abstract] | ||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||
| Other comprehensive income | — | — | — |
20,000,000
SEK
|
— |
20,000,000
SEK
|
— | — | — | — |
77,000,000
SEK
|
— | — |
77,000,000
SEK
|
— | — | — | — |
| Dividends recognised as distributions to owners | — | — | — | — | — |
475,000,000
SEK
|
475,000,000
SEK
|
— | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through other changes, equity | — | — | — | — | — | — | — |
4,000,000
SEK
|
— | — |
4,000,000
SEK
|
— | — | — | — | — | — | — |