Share-based compensation and employee benefit plans - Plan asset allocation (Details)	Dec. 31, 2021
International equities
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Plan asset allocation	15.00%
Swedish equities
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Plan asset allocation	12.70%
Swedish nominal bonds
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Plan asset allocation	33.90%
Real estate
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Plan asset allocation	8.90%
Private equity
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Plan asset allocation	14.60%
Other
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Plan asset allocation	14.90%