Segment Information - Summary of Long-Lived Assets by Geographical Areas (Detail) - USD ($) $ in Thousands |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|---|---|---|
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||||
| Property, plant and equipment | $ 16,256 | $ 20,447 | $ 21,718 | $ 25,475 | $ 26,568 |
| Right of use assets | 37 | 92 | 9,695 | ||
| Net book value | 343,233 | 344,653 | 348,045 | 380,592 | 318,962 |
| PRC (excluding Hong Kong) | |||||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||||
| Real estate properties under development | 191,549 | 180,514 | 174,692 | 184,603 | 190,492 |
| Property, plant and equipment | 16,250 | 20,447 | 21,718 | 25,475 | 26,389 |
| Real estate properties held for lease | 135,428 | $ 143,692 | 151,598 | 170,422 | 92,207 |
| Right of use assets | $ 37 | $ 92 | 9,511 | ||
| Hong Kong | |||||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||||
| Property, plant and equipment | $ 6 | 179 | |||
| Right of use assets | $ 184 |