Collaborations - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 9 Months Ended 12 Months Ended
Jul. 31, 2018
Mar. 31, 2019
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Jul. 31, 2021
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Payment of stock issuance costs     $ 232   $ 394  
Related party transactions revenue recognized     39,917 $ 26,749 9,514  
Contract with customers liability current     71,255 84,090    
Contract with customers liability non current       3,374    
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Aggregate receivables by the company pursuant to the agreement   $ 400,000     400,000  
Temporary equity fair value   272,700     272,700  
Performance obligation transaction price   127,300     127,300  
Cumulative payments received     75,000      
Related party transactions revenue recognized     39,900 26,700 9,500  
Contract with customers liability current     30,100 41,700    
Contract with customers liability non current     0 3,400    
Performance obligation revenue recognized       2,600    
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Accounts Payable and Accrued Liabilities [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Payable towards reimbursement of shared costs     11,500 7,800    
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Research and Development Expense [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Expenditure Incurred Pursuant To Cost Sharing Agreements     18,700 19,100 6,300  
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Cost of Sales [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Expenditure Incurred Pursuant To Cost Sharing Agreements     $ (1,400) $ 1,000 (200)  
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Annual Payment One [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Annual payment receivable by the company   25,000     25,000  
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Annual Payment Two [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Annual payment receivable by the company   25,000     25,000  
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Annual Payment Three [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Annual payment receivable by the company   25,000     25,000  
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Annual Payment Four [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Annual payment receivable by the company   25,000     25,000 $ 25,000
Glaxosmithkline Agreement [Member] | Glaxosmith Kline [Member] | Series F Redeemable Preferred Stock [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Temporary equity shares issued during the period shares 17,291,066          
Proceeds from redeemable preferred stock net $ 299,600          
Temporary equity issue price per share $ 17.35          
Payment of stock issuance costs $ 400          
Proceeds from redeemable preferred stock net   300,000        
Almirall Agreement [Member] | Almirall [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Performance obligation transaction price   2,700     2,700  
Almirall Agreement [Member] | Almirall [Member] | One Time Payment [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Performance obligation transaction price   2,500     2,500  
Almirall Agreement [Member] | Almirall [Member] | Payment Over Agreement Term [Member]            
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]            
Performance obligation transaction price   $ 200     $ 200