Share-based Compensation - Movements in Number of Stock-options Outstanding Under 2017 EIP (Detail) - Employee 2017 EIP [Member] |
12 Months Ended | |
|---|---|---|
|
Dec. 31, 2021
USD ($)
shares
$ / shares
|
Dec. 31, 2020
USD ($)
shares
$ / shares
|
|
| Disclosure of terms and conditions of share-based payment arrangement [Line Items] | ||
| At January 1, | 7,035,388 | 4,626,385 |
| Granted | 3,050,340 | 4,543,952 |
| Forfeited/Expired | (1,148,255) | (2,134,949) |
| At December 31, | 8,937,473 | 7,035,388 |
| At January 1, average exercise price | $ / shares | $ 6.49 | $ 10.51 |
| Granted, average exercise price | $ / shares | $ 3.29 | $ 2.93 |
| Forfeited/Expired, average exercise price | $ | $ 8.42 | $ 7.62 |
| At December 31, average exercise price | $ / shares | $ 5.15 | $ 6.49 |