Going concern - Additional Information (Detail) |
1 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
|
Oct. 31, 2021
USD ($)
Tranche
$ / shares
|
Dec. 31, 2021
USD ($)
|
Dec. 31, 2020
USD ($)
|
Dec. 31, 2019
USD ($)
|
Dec. 31, 2018
USD ($)
|
|
| Disclosure Of Going Concern [Line Items] | |||||
| Net loss | $ 58,377,000 | $ 82,966,000 | $ 108,790,000 | ||
| Accumulated losses | 467,800,000 | ||||
| Share premium offset from accumulated losses | 30,600,000 | ||||
| Cash and cash equivalents | $ 54,734,000 | 31,183,000 | $ 69,370,000 | $ 138,640,000 | |
| Securities Purchase Agreement With JGB Management, Inc. [Member] | |||||
| Disclosure Of Going Concern [Line Items] | |||||
| Maximum borrowing capacity of financing agreement | $ 135,000,000 | ||||
| Number of tranches | Tranche | 9 | ||||
| Weighted average share price | $ / shares | $ 3.00 | ||||
| First tranche funded closing date | Oct. 31, 2021 | ||||
| Second tranche funded closing date | Jan. 31, 2022 | ||||
| Description of minimum stock price | The Securities Purchase Agreement is structured to provide USD 135 million in borrowing capacity, available in nine tranches, with the first tranche funded at the initial closing in October 2021 and the second tranche funded in January 2022 in connection with certain amendments to the Securities Purchase Agreement as described in Note 24. The subsequent tranches under the Securities Purchase Agreement will be available subject to the Company meeting certain conditions, including, among others, that the Company’s volume-weighted average price is not below USD 3.00 per share for five or more trading days during the 30 days prior to a tranche funding date (the “Minimum Stock Price”). | ||||
| COVID-19 pandemic [Member] | |||||
| Disclosure Of Going Concern [Line Items] | |||||
| Cash and cash equivalents | $ 54,700,000 | ||||