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Treasury stock (Tables) | 12 Months Ended
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Dec. 31, 2019
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Movement of Treasury Stock | As of December 31, 2017 and 2018, the reasons for share repurchases and movements in the number of the Company’s treasury stock are as follows:
|  | 2017 |  |  | 2018 |
|  | Shares |  |  | Amount |  |  | Shares |  |  | Amount |
|  | in thousands |  |  | NT$000 |  |  | in thousands |  |  | NT$000 |
January 1 |  |  | 30,085 |  |  |  | 1,007,654 |  |  |  | 30,085 |  |  |  | 1,007,654 |
Capital reduction |  |  | — |  |  |  | — |  |  |  | (4,515 | ) |  |  | (45,151 | )
December 31 |  |  | 30,085 |  |  |  | 1,007,654 |  |  |  | 25,570 |  |  |  | 962,503 |

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- Definition Disclosure of detailed information of treasury shares. + References No definition available. + Details
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- Definition Text block [abstract] + References No definition available. + Details
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