Shareholders' equity Dividends Declared (Details)	3 Months Ended				6 Months Ended
	Jun. 30, 2025 SFr / shares	Jun. 30, 2025 $ / shares	Jun. 30, 2024 SFr / shares	Jun. 30, 2024 $ / shares	Jun. 30, 2025 SFr / shares	Jun. 30, 2025 $ / shares	Jun. 30, 2024 SFr / shares	Jun. 30, 2024 $ / shares
Equity, Class of Treasury Stock [Line Items]
Common Stock, Dividends, Per Share, Declared | (per share)	SFr 0.81	$ 0.97	SFr 0.82	$ 0.91	SFr 1.62	$ 1.88	SFr 1.57	$ 1.77