Quarterly report pursuant to Section 13 or 15(d)

Debt - Additional Information (Details)

v3.21.2
Debt - Additional Information (Details)
1 Months Ended 3 Months Ended 8 Months Ended 9 Months Ended 12 Months Ended
Nov. 02, 2020
USD ($)
$ / shares
shares
Sep. 08, 2020
USD ($)
Debtinstrument
$ / shares
shares
Apr. 30, 2020
USD ($)
Jan. 21, 2020
USD ($)
Debtinstrument
$ / shares
shares
Apr. 27, 2018
USD ($)
$ / shares
shares
Dec. 31, 2020
USD ($)
Nov. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
$ / shares
shares
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
$ / shares
shares
Sep. 30, 2021
USD ($)
$ / shares
shares
Sep. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Debt Instrument [Line Items]                          
Number of warrants to purchase ordinary shares | shares               380,000   380,000 380,000    
Accretion of debt discounts and deferred financing costs                     $ 3,636,000 $ 7,818,000  
Debt instrument, outstanding principal               $ 15,961,000   $ 15,961,000 $ 15,961,000    
Fair value of derivative liability       $ 27,038,000                  
Financing transaction costs                 $ 685,000     2,815,000  
Ordinary Shares                          
Debt Instrument [Line Items]                          
Number of warrants to purchase ordinary shares | shares         19,890     19,890   19,890 19,890    
Loan and Security Agreement | Silicon Valley Bank (SVB)                          
Debt Instrument [Line Items]                          
Loan and security agreement entered date                     Apr. 27, 2018    
Funded amount under agreement         $ 15,000,000                
Remaining borrowing facility available date         Oct. 31, 2019                
Maximum amount available under agreement         $ 30,000,000                
Non-utilization fee percentage of undrawn principal amount         1.50%                
Frequency of amortization payments                     Monthly    
Date of first required payment of initial draw         Nov. 01, 2019                
Minimum fixed interest rate per annum         8.31%                
Final interest rate payment on outstanding principal         4.20%                
Principal and interest payment, maturity date         Mar. 01, 2022                
Final payment fee         $ 630,000                
Prepayment fee in first year         4.00%                
Prepayment fee in second year         3.00%                
Prepayment fee thereafter         2.00%                
Principal payment during the period                     $ 4,655,000    
Effective annual interest rate on outstanding debt               12.51%   12.51% 12.51%    
Interest expense               $ 116,000 315,000   $ 490,000 1,091,000  
Accretion of debt discounts and deferred financing costs               $ 28,000 95,000   $ 130,000 324,000  
Loan and Security Agreement | Silicon Valley Bank (SVB) | Wall Street Journal Prime Rate                          
Debt Instrument [Line Items]                          
Basis spread on interest rate         3.89%                
Loan and Security Agreement | Silicon Valley Bank (SVB) | Maximum                          
Debt Instrument [Line Items]                          
Maximum amount available under second draw         $ 15,000,000                
Silicon Valley Bank and Life Sciences Fund II LLC                          
Debt Instrument [Line Items]                          
Percentage of purchase additional ordinary shares equal to term loan divided by applicable exercise price         2.50%                
Silicon Valley Bank and Life Sciences Fund II LLC | Series B Convertible Preferred Shares                          
Debt Instrument [Line Items]                          
Number of warrants to purchase ordinary shares | shares         19,890     19,890   19,890 19,890    
Warrants to purchase ordinary shares, exercise price | $ / shares         $ 18.85     $ 18.85   $ 18.85 $ 18.85    
2025 Exchangeable Notes                          
Debt Instrument [Line Items]                          
Interest expense               $ 205,000 860,000   $ 873,000 2,339,000  
Accretion of debt discounts and deferred financing costs               591,000 $ 2,062,000   2,302,000 $ 5,665,000  
Aggregate principal amount       9,891,000                  
Debt instrument, outstanding principal               12,607,000   $ 12,607,000 $ 12,607,000    
Debt instrument, payment terms                     The Company will be required to pay the holder of the Exchangeable Notes the greater of three times the outstanding principal amount of such Exchangeable Note and the consideration that would be received by the holder of such Exchangeable Note in connection with such Fundamental Change if the holder had exchanged its note for ordinary shares immediately prior to the consummation of such Fundamental Change, plus any accrued and unpaid interest.    
Fair value of derivative liability       27,038,000                  
Fair value of derivative liability related to rights offering       82,000                  
Financing transaction costs                         $ 2,815,000
Financing transaction costs, capitalized           $ 2,814,000             $ 2,814,000
2025 Exchangeable Notes | Private Placement                          
Debt Instrument [Line Items]                          
Aggregate principal amount   $ 200,000   $ 51,600,000                  
Debt instrument interest rate   6.50%   6.50%                  
Debt instrument price per unit   $ 1,000   $ 1,000                  
Aggregate principal amount               39,200,000   $ 39,200,000 $ 39,200,000    
Notes exchanged for ordinary shares | shares                   53,888,331      
Debt instrument, outstanding principal               12,600,000   $ 12,600,000 12,600,000    
RLNs | Private Placement                          
Debt Instrument [Line Items]                          
Aggregate principal amount   $ 20,000.00   $ 100,000                  
Number of debt instruments within each notes | Debtinstrument   50   50                  
Securities | Private Placement                          
Debt Instrument [Line Items]                          
Debt instrument price per unit   $ 1,000   $ 1,000                  
Debt instrument, shares embedded within each unit, shares | shares 1,286.1845 1,000   1,000                  
Debt instrument, shares embedded within each unit, value $ 1,000 $ 1,000   $ 1,000                  
Debt instrument, shares embedded within each unit, exchange price | $ / shares $ 0.7775 $ 1.00   $ 1.00                  
Paycheck Protection Program | Silicon Valley Bank (SVB) | Iterum Therapeutics US Limited                          
Debt Instrument [Line Items]                          
Interest expense               $ 1,000     $ 1,000    
Aggregate principal amount     $ 744,000                    
Debt instrument interest rate     1.00%                    
Debt instrument maturity period     2 years                    
Debt instrument, description     Under the terms of the agreement, there shall be no payments due by the Company until the SBA remits the forgiveness amount to the Borrower or 10 months after the end of the six-month period beginning April 30, 2020 (the Deferral Period). Following the Deferral Period, equal monthly repayments of principal and interest will be due to fully amortize the principal amount outstanding on the PPP loan by the maturity date.               Under the terms of the agreement, there shall be no payments due by the Company until the SBA remits the forgiveness amount to the Borrower or until after the Deferral Period. Following the Deferral Period, equal monthly repayments of principal and interest will be due to fully amortize the principal amount outstanding on the PPP loan by the maturity date.    
Debt instrument, forgiveness loan             $ 340,000            
Debt instrument, remaining amount amortized           $ 404,000              
Debt Instrument, principal repayments                     $ 231,000