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 |
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 |
As at 2020-12-31 |
As at 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 |
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 2019-12-31 |
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 |
3 076
SEK
|
57,000,000
SEK
|
1 844
SEK
|
— | — |
5 844
SEK
|
5 844
SEK
|
867,000,000
SEK
|
— | — | — |
1 405
SEK
|
42,000,000
SEK
|
1 844
SEK
|
0
SEK
|
3 972
SEK
|
867,000,000
SEK
|
0
SEK
|
— |
42,000,000
SEK
|
14 4
SEK
|
— |
3 972
SEK
|
— |
3 044
SEK
|
23,000,000
SEK
|
1 844
SEK
|
3 044
SEK
|
357,000,000
SEK
|
867,000,000
SEK
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||
| Profit (loss) | — | — | — | — |
1 508
SEK
|
— | — | — |
1 508
SEK
|
1 508
SEK
|
1 259
SEK
|
— | — | — | — | — | — | — |
1 259
SEK
|
— | — | — | — |
1 259
SEK
|
— | — | — | — | — | — |
| Other comprehensive income | — | — | — |
15 7
SEK
|
905,000,000
SEK
|
— | — | — |
90 5
SEK
|
74 8
SEK
|
3 2
SEK
|
— | — | — | — | — | — | — |
88,000,000
SEK
|
— | — |
12 1
SEK
|
— |
3 2
SEK
|
— | — | — | — | — | — |
| Comprehensive income | — | — | — |
15 7
SEK
|
2 413
SEK
|
— | — | — |
2 413
SEK
|
2 256
SEK
|
1 226
SEK
|
— | — | — | — | — | — | — |
1 347
SEK
|
— | — |
12 1
SEK
|
— |
1 226
SEK
|
— | — | — | — | — | — |
| Dividends recognised as distributions to owners | — | — | — | — |
5 38
SEK
|
— | — | — |
5 3 8
SEK
|
5 38
SEK
|
2 6 9
SEK
|
— | — | — | — | — | — | — |
26 9
SEK
|
— | — | — | — |
26 9
SEK
|
— | — | — | — | — | — |
| Increase (decrease) through treasury share transactions, equity | — | — | — | — |
13,000,000
SEK
|
— | — | — |
13,000,000
SEK
|
13,000,000
SEK
|
3 4
SEK
|
— | — | — | — | — | — | — |
3 4
SEK
|
— | — | — | — |
3 4
SEK
|
— | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — | — | — | — |
10,000,000
SEK
|
— | — | — |
10,000,000
SEK
|
10,000,000
SEK
|
4,000,000
SEK
|
— | — | — | — | — | — | — |
4,000,000
SEK
|
— | — | — | — |
4,000,000
SEK
|
— | — | — | — | — | — |