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Operating Segments Information - Summary of Segment Information (Detail) $ in Thousands, $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 TWD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 TWD ($) | Dec. 31, 2017 TWD ($) | Dec. 31, 2019 USD ($)
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | $ 413,182,184 | $ 13,814,182 | $ 371,092,421 | $ 290,441,208 |
Interest income | 549,681 | 18,378 | 466,211 | 306,871 |
Interest expense | (4,186,855) | (139,982) | (3,535,886) | (1,774,886) |
Depreciation and amortization | (50,466,841) | (1,687,290) | (42,688,903) | (29,205,184) |
Share of the profit or loss of associates and joint ventures | 182,275 | 6,094 | (480,244) | 525,782 |
Impairment loss | (601,207) | (20,100) | (654,081) | (764,881) |
Segment profit before income tax | 23,279,811 | 778,328 | 31,937,678 | 31,020,663 |
Expenditures for segment assets | 63,073,887 | 2,108,789 | 39,092,238 | 23,677,682 |
Investments accounted for using the equity method | 12,085,207 |  | 9,312,308 | 48,753,751 | $ 404,052
Contract assets | 5,897,316 |  | 4,488,500 |  | 197,169
Packaging segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 198,916,897 | 6,650,515 | 178,308,222 | 126,225,119 |
Interest income | 186,291 | 6,228 | 166,761 | 43,744 |
Interest expense | (3,403,475) | (113,791) | (3,647,601) | (1,969,562) |
Depreciation and amortization | (33,456,831) | (1,118,583) | (29,491,977) | (19,105,457) |
Share of the profit or loss of associates and joint ventures | 75,303 | 2,518 | (456,846) | 568,291 |
Impairment loss | (601,066) | (20,096) | (654,081) | (218,214) |
Segment profit before income tax | 7,572,763 | 253,185 | 17,866,431 | 12,065,304 |
Expenditures for segment assets | 35,462,305 | 1,185,634 | 22,787,190 | 17,769,612 |
Investments accounted for using the equity method | 8,867,316 |  | 9,152,290 | 48,566,333 | 296,467
Contract assets | 4,162,124 |  | 3,488,372 |  | 139,155
Testing segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 42,658,686 | 1,426,235 | 35,903,202 | 26,157,277 |
Interest income | 90,091 | 3,012 | 55,108 | 48,532 |
Interest expense | (545,609) | (18,242) | (101,338) | (11,920) |
Depreciation and amortization | (12,379,703) | (413,899) | (9,560,610) | (6,476,743) |
Share of the profit or loss of associates and joint ventures | 39,852 | 1,332 | (23,398) | (42,509) |
Impairment loss | (141) | (4) |  | (72,798) |
Segment profit before income tax | 10,321,537 | 345,086 | 7,952,484 | 6,904,067 |
Expenditures for segment assets | 23,966,051 | 801,272 | 12,991,023 | 4,507,097 |
Investments accounted for using the equity method | 1,123,490 |  | 160,018 | 187,418 | 37,562
Contract assets | 1,735,192 |  | 1,000,128 |  | 58,014
EMS segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 165,789,479 | 5,542,945 | 151,890,384 | 133,948,016 |
Interest income | 249,487 | 8,341 | 354,343 | 269,640 |
Interest expense | (255,404) | (8,539) |  |  |
Depreciation and amortization | (2,534,825) | (84,748) | (2,065,590) | (2,133,253) |
Share of the profit or loss of associates and joint ventures | 67,120 | 2,244 |  |  |
Segment profit before income tax | 6,082,106 | 203,348 | 6,225,984 | 6,883,327 |
Expenditures for segment assets | 2,770,129 | 92,615 | 2,529,771 | 850,235 |
Investments accounted for using the equity method | 2,094,401 |  |  |  | $ 70,023
All other segments [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 5,817,122 | 194,487 | 4,990,613 | 4,110,796 |
Interest income | 284,458 | 9,511 | 352,232 | 214,265 |
Interest expense | (243,013) | (8,124) | (249,180) | (62,714) |
Depreciation and amortization | (2,095,482) | (70,060) | (1,570,726) | (1,489,731) |
Impairment loss |  |  |  | (473,869) |
Segment profit before income tax | (696,595) | (23,291) | (107,221) | 5,167,965 |
Expenditures for segment assets | 875,402 | 29,268 | 784,254 | 550,738 |
Adjustments and Eliminations [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Interest income | (260,646) | (8,714) | (462,233) | (269,310) |
Interest expense | 260,646 | 8,714 | 462,233 | 269,310 |
Inter-group revenues [member] | Packaging segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 5,370,963 | 179,571 | 3,531,431 | 4,911,026 |
Inter-group revenues [member] | Testing segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 231,399 | 7,736 | 212,310 | 184,707 |
Inter-group revenues [member] | EMS segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 60,638,567 | 2,027,368 | 58,836,465 | 47,119,404 |
Inter-group revenues [member] | All other segments [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 7,431,399 | 248,459 | 7,637,053 | 8,383,640 |
Inter-group revenues [member] | Adjustments and Eliminations [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | (73,672,328) | (2,463,134) | (70,217,259) | (60,598,777) |
Operating segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 486,854,512 | 16,277,316 | 441,309,680 | 351,039,985 |
Operating segment [member] | Packaging segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 204,287,860 | 6,830,086 | 181,839,653 | 131,136,145 |
Operating segment [member] | Testing segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 42,890,085 | 1,433,971 | 36,115,512 | 26,341,984 |
Operating segment [member] | EMS segment [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | 226,428,046 | 7,570,313 | 210,726,849 | 181,067,420 |
Operating segment [member] | All other segments [member] |  |  |  |  |
Disclosure of operating segments [line items] |  |  |  |  |
Operating revenue | $ 13,248,521 | $ 442,946 | $ 12,627,666 | $ 12,494,436 |

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- Definition The entity's share of the profit (loss) of associates and joint ventures accounted for using the equity method. [Refer: Associates [member]; Investments accounted for using equity method; Joint ventures [member]; Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2019-01-01 -Paragraph 23 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_23_g&doctype=Standard -URIDate 2019-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2019-01-01 -Paragraph 28 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_28_e&doctype=Standard -URIDate 2019-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Note Effective on first application of IFRS 9 -Name IFRS -Number 4 -IssueDate 2019-01-01 -Paragraph 39M -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2019-en-b&anchor=para_39M_b&doctype=Standard -URIDate 2019-03-27 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 82 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_82_c&doctype=Standard -URIDate 2019-03-27 + Details
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