Income Taxes and Deferred Taxes - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Disclosure of Income Tax [Abstract]      
Statutory tax rate (blended at Group level) 8.50% 7.90%  
ObsEva Ireland Ltd [Member]      
Disclosure of Income Tax [Abstract]      
Current tax expense (income) $ 0 $ 0  
ObsEva USA Inc [Member]      
Disclosure of Income Tax [Abstract]      
Statutory tax rate (blended at Group level) 27.30% 27.30%  
Current tax expense (income) $ 212,000 $ 34,000  
Deferred taxes $ 0 0  
Switzerland [Member]      
Disclosure of Income Tax [Abstract]      
Tax loss carryforward period 7 years    
Current tax expense (income)   0 $ 0
Deferred taxes $ 0 $ 0  
Switzerland [Member] | Municipal and Cantonal Tax Rate [Member]      
Disclosure of Income Tax [Abstract]      
Statutory tax rate (blended at Group level) 14.00% 14.00%  
Switzerland [Member] | Federal Tax Rate [Member]      
Disclosure of Income Tax [Abstract]      
Statutory tax rate (blended at Group level) 8.50% 8.50%