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Equity Transaction with Non-controlling Interests - Additional Information (Detail) $ / shares in Units, $ / shares in Units, ¥ in Thousands, shares in Thousands, $ in Thousands, $ in Thousands | 1 Months Ended | 12 Months Ended |  |  |  |  |
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Jan. 31, 2018 $ / shares shares | Jan. 31, 2017 TWD ($) | Jan. 31, 2017 USD ($) | Feb. 29, 2016 shares | Feb. 28, 2016 TWD ($) $ / shares shares | Jan. 31, 2016 | Apr. 30, 2015 CNY (¥) shares | Mar. 31, 2015 | Dec. 31, 2017 TWD ($) $ / shares shares | Dec. 31, 2017 USD ($) | Dec. 31, 2017 USD ($) shares | Oct. 13, 2017 shares | Jul. 13, 2017 shares | Dec. 31, 2016 TWD ($) | Jun. 30, 2015 TWD ($)
Sale of shares |  |  |  |  |  |  |  |  |  |  |  | 323,094 | 101,164 |  |
Proceeds from issuance of shares |  |  |  |  |  |  |  |  | $ 10,290,000 | $ 347,166 |  |  |  |  |
Cash capital increase [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of shares |  |  |  |  |  |  |  |  | 300,000 |  | 300,000 |  |  |  |
Sale of shares per share | $ / shares |  |  |  |  |  |  |  |  | $ 34.3 |  |  |  |  |  |
USI Enterprise Limited [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase (decrease) in capital surplus | $ |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (1,912,887) | $ 7,197,510
Number of shares repurchased |  |  |  | 4,501 |  |  |  |  |  |  |  |  |  |  |
Percentage of increase in shareholdings |  |  |  | 98.80% |  | 96.70% |  |  |  |  |  |  |  |  |
Number of shares approved for repurchase | 3,738,420 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares repurchase price per share | $ / shares | $ 17.49 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Universal Scientific Industrial (Shanghai) Co., Ltd [member] | USI Enterprise Limited [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of shares | ¥ |  |  |  |  |  |  | ¥ 1,992,060 |  |  |  |  |  |  |  |
Universal Scientific Industrial (Shanghai) Co., Ltd [member] | USI Enterprise Limited [member] | Ordinary shares [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of shares |  |  |  |  |  |  | 54,000 |  |  |  |  |  |  |  |
Percentage of decrease in shareholdings |  |  |  |  |  |  | 77.20% | 82.10% |  |  |  |  |  |  |
Universal Global Scientific Industrial Co., Ltd. [member] | USI [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of shares |  |  |  |  | 39,603 |  |  |  |  |  |  |  |  |  |
Percentage of decrease in shareholdings |  |  |  |  | 76.50% | 99.00% |  |  |  |  |  |  |  |  |
Increase (decrease) in capital surplus | $ |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (20,552) |
Sale of shares per share | $ / shares |  |  |  |  | $ 20 |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of shares | $ |  |  |  |  | $ 792,064 |  |  |  |  |  |  |  |  |  |
USI [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Increase (decrease) in capital surplus |  |  |  |  |  |  |  |  | $ 3,055 |  | $ 103 |  |  |  |
Percentage of increase in shareholdings |  | 75.20% | 75.20% |  |  |  |  |  |  |  |  |  |  |  |
Cash capital increase amount |  | $ 1,000,000 | $ 33,738 |  |  |  |  |  |  |  |  |  |  |  |
USI [member] | Cash capital increase [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of increase in shareholdings |  | 75.70% | 75.70% |  |  |  |  |  |  |  |  |  |  |  |

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