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Earnings Per Share - Income and Share Data Used in Basic and Diluted EPS Computations (Detail) $ / shares in Units, $ / shares in Units, shares in Thousands, $ in Thousands, $ in Thousands | 12 Months Ended
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Dec. 31, 2019 TWD ($) $ / shares shares | Dec. 31, 2019 USD ($) $ / shares shares | Dec. 31, 2018 TWD ($) $ / shares shares | Dec. 31, 2017 TWD ($) $ / shares shares
Basic earnings per share, amount after tax |  |  |  |
Equity holders of the Company - Continuing operations, amount after tax | $ 2,508,574 | $ 83,871 | $ 1,325,824 | $ 981,929
Equity holders of the Company - Discontinued operations, amount after tax |  |  |  | 1,814,953
Profit attributable to equity holders of the Company, amount after tax | 2,508,574 |  | 1,325,824 | 2,796,882
Diluted earnings per share, amount after tax |  |  |  |
Equity holders of the Company - Continuing operations, amount after tax | 2,508,574 | 83,871 | 1,325,824 | 981,929
Equity holders of the Company - Discontinued operations, amount after tax |  |  |  | 1,814,953
Equity holders of the Company, amount after tax | $ 2,508,574 |  | $ 1,325,824 | $ 2,796,882
Weighted-average number of ordinary shares outstanding | 727,111 | 727,111 | 802,725 | 846,686
Diluted earnings per share, weighted-average number of ordinary shares outstanding |  |  |  |
Employees' compensations | 9,879 | 9,879 | 7,626 | 14,034
Restricted shares | 126 | 126 | 3,356 | 5,075
Weighted-average number of ordinary shares outstanding | 737,116 | 737,116 | 813,707 | 865,795
Ordinary shares [member] |  |  |  |
Basic earnings per share |  |  |  |
Equity holders of the Company - Continuing operations, earnings per share | (per share) | $ 3.45 | $ 0.12 | $ 1.65 | $ 1.16
Equity holders of the Company - Discontinued operations, earnings per share | (per share) |  |  |  | 2.14
Equity holders of the Company - Earnings per share | (per share) | 3.45 | 0.12 | 1.65 | 3.30
Diluted earnings per share |  |  |  |
Equity holders of the Company - Continuing operations, earnings per share | (per share) | 3.40 | 0.11 | 1.63 | 1.13
Equity holders of the Company - Discontinued operations, earnings per share | (per share) |  |  |  | 2.10
Equity holders of the Company - Earnings per share | (per share) | $ 3.40 | $ 0.11 | $ 1.63 | $ 3.23

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- Definition The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 33 -IssueDate 2019-01-01 -Paragraph 66 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=33&code=ifrs-tx-2019-en-r&anchor=para_66&doctype=Standard -URIDate 2019-03-27 + Details
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