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Share Capital - Additional Information (Detail) SFr / shares in Units, $ / shares in Units, $ in Thousands		1 Months Ended		3 Months Ended	6 Months Ended		12 Months Ended
	May 19, 2025 SFr / shares shares	Oct. 31, 2025 USD ($)	Jan. 31, 2021 USD ($)	Jun. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2026 USD ($) $ / shares shares	Jun. 30, 2025 USD ($) $ / shares shares	Dec. 31, 2025 USD ($) $ / shares	Jun. 30, 2026 SFr / shares shares	Jun. 30, 2026 $ / shares shares	Dec. 31, 2025 SFr / shares shares	Jun. 08, 2023 CHF (SFr) SFr / shares
Class of Stock [Line Items]
Common shares, nominal value \| SFr / shares								SFr 0.03		SFr 0.03	SFr 0.03
Proceeds from issuance of common shares					$ (722)	$ 8,494
Registered share capital \| shares								98,599,444	98,599,444
Registered common shares \| shares								9,366,947	9,366,947
Common shares employee equity incentive plans \| shares								17,686,403	17,686,403
2021 ATM [Member]
Class of Stock [Line Items]
Average issue price of common shares \| $ / shares							$ 74.77
Proceeds from issuance of common shares							$ 592,200
Equity issuance costs							7,800
Common shares issued \| shares										8,000,000
Stamp taxes on issuance of common stock							$ 5,900
Number of remaining common shares available \| shares										0
Capital Band [Member]
Class of Stock [Line Items]
Common shares issued \| shares								18,795,173	18,795,173
Maximum [Member]
Class of Stock [Line Items]
Common stock share capital value \| SFr											SFr 3,521,838.51
Sales Agreement With Jefferies LLC [Member] \| 2021 ATM [Member]
Class of Stock [Line Items]
Average issue price of common shares \| $ / shares				$ 54.33		$ 54.33
Proceeds from issuance of common shares				$ 8,700		$ 8,700
Equity issuance costs				$ 100		$ 100
Issuance of common shares \| shares				200,000		200,000
Stamp taxes on issuance of common stock				$ 100		$ 100
Sales Agreement With Jefferies LLC [Member] \| 2025 ATM [Member]
Class of Stock [Line Items]
Aggregate estimated gross proceeds					$ 557,200
Average issue price of common shares \| $ / shares					$ 60.81
Proceeds from issuance of common shares					$ 42,300
Equity issuance costs					500
Common shares issued \| shares								0	0
Common shares issued \| shares								700,000	700,000
Stamp taxes on issuance of common stock					$ 400
Sales Agreement With Jefferies LLC [Member] \| Maximum [Member] \| 2021 ATM [Member]
Class of Stock [Line Items]
Aggregate estimated gross proceeds			$ 600,000
Sales Agreement With Jefferies LLC [Member] \| Maximum [Member] \| 2025 ATM [Member]
Class of Stock [Line Items]
Aggregate estimated gross proceeds		$ 600,000
Sirius Therapeutics [Member]
Class of Stock [Line Items]
Common shares, nominal value \| SFr / shares	SFr 0.03
Share price \| $ / shares									$ 38
Issuance of common shares \| shares	1,842,105				1,842,105