Debt (Subsequent event) (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Jul. 31, 2023	Jun. 30, 2023	Jun. 30, 2022
Debt
Aggregate principal amount to redeem		$ 1,380	$ 18
Aggregate cash payment		$ 1,402	$ 18
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Debt
Debt instrument interest rate stated percentage		2.50%
2.50% Senior Guaranteed Exchangeable Bonds due January 2027 | Subsequent Events
Debt
Aggregate principal amount to redeem	$ 25
2.50% Senior Guaranteed Exchangeable Bonds due January 2027 | Forecast
Debt
Aggregate cash payment	$ 25