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 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 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 |
As at 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 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 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 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||
| Equity |
440,000,000
SEK
|
9,074,000,000
SEK
|
8,957,000,000
SEK
|
— | — |
286,000,000
SEK
|
37,000,000
SEK
|
— | — | — | — |
1,429,000,000
SEK
|
6,234,000,000
SEK
|
34,000,000
SEK
|
— |
156,000,000
SEK
|
— |
4,684,000,000
SEK
|
— | — |
-
SEK
|
3,971,000,000
SEK
|
2,193,000,000
SEK
|
1,804,000,000
SEK
|
26,000,000
SEK
|
| Changes in equity [abstract] | |||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||
| Profit (loss) | — | — | — | — | — | — | — | — |
918,000,000
SEK
|
918,000,000
SEK
|
375,000,000
SEK
|
— | — | — |
375,000,000
SEK
|
— | — | — | — | — | — | — | — | — | — |
| Other comprehensive income | — | — | — |
442,000,000
SEK
|
— | — | — | — |
442,000,000
SEK
|
— |
156,000,000
SEK
|
— | — | — | — | — | — | — | — |
156,000,000
SEK
|
— | — | — | — | — |
| Comprehensive income | — | — | — |
442,000,000
SEK
|
— | — | — | — |
1,361,000,000
SEK
|
918,000,000
SEK
|
218,000,000
SEK
|
— | — | — |
375,000,000
SEK
|
— | — | — | — |
156,000,000
SEK
|
— | — | — | — | — |
| Issue of equity | — | — | — | — |
1,000,000
SEK
|
— | — |
1,457,000,000
SEK
|
1,458,000,000
SEK
|
— |
2,242,000,000
SEK
|
— | — | — | — | — |
2,234,000,000
SEK
|
— |
8,000,000
SEK
|
— | — | — | — | — | — |
| Increase (decrease) through other changes, equity | — | — | — | — | — | — | — |
8,000,000
SEK
|
8,000,000
SEK
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |