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Business Combinations - Additional Information (Detail) $ / shares in Units, $ / shares in Units, $ in Thousands, $ in Thousands | 1 Months Ended | 12 Months Ended |  |
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May 31, 2018 $ / shares | May 31, 2018 $ / shares | Dec. 31, 2018 USD ($) | Dec. 31, 2018 TWD ($) | Dec. 31, 2018 TWD ($) | May 31, 2016 TWD ($)
Disclosure of subsidiaries [Line Items] |  |  |  |  |  |
Significant unobservable inputs discount rate |  |  | 25.00% | 25.00% |  |
Revenue from continuing operations |  |  | $ 12,978,159 | $ 397,261,461 |  |
Profit from continuing operations |  |  | $ 838,766 | $ 25,674,641 |  |
TLJ Intertech Inc. [member] |  |  |  |  |  |
Disclosure of subsidiaries [Line Items] |  |  |  |  |  |
Percentage of shareholdings acquired by subsidiary |  |  | 60.00% |  | 60.00% | 60.00%
Total consideration was paid to key management personnel and related parties |  |  |  |  | $ 89,998 |
TLJ Intertech Inc. [member] | Related parties [member] |  |  |  |  |  |
Disclosure of subsidiaries [Line Items] |  |  |  |  |  |
Total consideration was paid to key management personnel and related parties |  |  |  |  |  | $ 41,739
Siliconware Precision Industries Co., Ltd. [member] |  |  |  |  |  |
Disclosure of subsidiaries [Line Items] |  |  |  |  |  |
Percentage of shareholdings acquired by subsidiary | 100.00% | 100.00% | 100.00% |  | 100.00% |
Total consideration was paid to key management personnel and related parties |  |  | $ 5,502,796 |  | $ 168,440,585 |
Cash consideration | (per share) | $ 51.2 | $ 1.7 |  |  |  |

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- Definition The fair value, at acquisition date, of the consideration transferred in a business combination. [Refer: Business combinations [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 3 -IssueDate 2018-01-01 -Paragraph B64 -Subparagraph f -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=3&date=2018-03-01&anchor=para_B64_f&doctype=Appendix&seq=2 -URIDate 2018-03-16 + Details
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