Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.22.1
Summary of Significant Accounting Policies - Additional Information (Details)
$ / shares in Units, € in Thousands
 1 Months Ended 12 Months Ended
Jun. 30, 2017
USD ($)
Dec. 31, 2021
USD ($)
Segment
$ / shares
Dec. 31, 2020
USD ($)
$ / shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2021
EUR (€)
Jan. 28, 2021
$ / shares
Jun. 10, 2020
$ / shares
Mar. 13, 2018
$ / shares
Mar. 12, 2018
$ / shares
May 18, 2017
$ / shares
Nov. 18, 2015
$ / shares
Oct. 14, 2015
$ / shares
Accounting Policies [Line Items]                            
Ordinary shares, par value | $ / shares   $ 0.01 $ 0.01         $ 0.01 $ 0.01 $ 0.001 $ 0.0001 $ 0.01 $ 0.01 $ 0.01
Research and development funding arrangement, sub award granted $ 1,500,000                          
Cost reimbursement arrangement recognition period 20 months                          
Cost reimbursement arrangement recognition beginning period 2017-08                          
Revenue   $ 0 $ 0 $ 37,000                    
Revenue, Product and Service [Extensible Enumeration]   us-gaap:GrantMember us-gaap:GrantMember us-gaap:GrantMember                    
Recognized income tax positions measured at largest amount greater than percentage of being realized   50.00%                        
Number of business segments | Segment   1                        
Defined Contribution Plan, Tax Status [Extensible Enumeration]   us-gaap:QualifiedPlanMember                        
Inventory   $ 0 $ 0                      
Milestone payments   $ 0                        
U.S. Tax Authority                            
Accounting Policies [Line Items]                            
Federal statutory tax rate   21.00% 21.00% 21.00% 21.00% 34.00%                
October Offering                            
Accounting Policies [Line Items]                            
Ordinary shares, par value | $ / shares   $ 0.01 $ 0.01                      
June 3 SPA                            
Accounting Policies [Line Items]                            
Ordinary shares, par value | $ / shares   0.01 0.01                      
June 30 SPA                            
Accounting Policies [Line Items]                            
Ordinary shares, par value | $ / shares   $ 0.01 $ 0.01                      
Certificates Of Deposit                            
Accounting Policies [Line Items]                            
Restricted cash   $ 30,000 $ 90,000                      
Warrants Issued | October Offering                            
Accounting Policies [Line Items]                            
Restricted cash   11,000 182,000                      
Warrants Issued | June 3 SPA                            
Accounting Policies [Line Items]                            
Restricted cash   17,000 17,000                      
Warrants Issued | June 30 SPA                            
Accounting Policies [Line Items]                            
Restricted cash   6,000 $ 19,000                      
Maximum                            
Accounting Policies [Line Items]                            
Cash, FDIC insured amount   250,000                        
Cash, DGS insured amount   $ 114,000         € 100              
Defined contribution plan, employee minimum percentage of total plan assets   60.00%                        
Defined contribution plan, maximum deferral rate   3.00%