XML 50 R53.htm IDEA: XBRL DOCUMENT
v3.20.1

Income tax expense (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2019
Text block [abstract] |
Major Components of Income Tax Expense |
| (a) | Components of income tax expense:
|  | 2017 |  |  | 2018 |  |  | 2019 |
|  | NT$000 |  |  | NT$000 |  |  | NT$000 |
Current income tax: |  |  |  |  |  |  |  |  |  |  |  |
Current income tax on profits for the period |  |  | 125,376 |  |  |  | 326,057 |  |  |  | 408,788 |
Income tax on unappropriated retained earnings |  |  | 246,684 |  |  |  | 28,165 |  |  |  | 74,540 |
Prior year income tax under (over) estimation |  |  | 67,885 |  |  |  | 3,729 |  |  |  | (5,016 | )
Total current income tax |  |  | 439,945 |  |  |  | 357,951 |  |  |  | 478,312 |
Deferred income tax: |  |  |  |  |  |  |  |  |  |  |  |
Relating to origination and reversal of temporary differences |  |  | 110,542 |  |  |  | 101,441 |  |  |  | 35,367 |
Impact of change in tax rate |  |  | — |  |  |  | (2,774 | ) |  |  | — |
Total deferred income tax |  |  | 110,542 |  |  |  | 98,667 |  |  |  | 35,367 |
Income tax expense |  |  | 550,487 |  |  |  | 456,618 |  |  |  | 513,679 |
Deferred Tax Charged to Other Comprehensive Income |
| (b) | The income tax (charge)/credit relating to components of other comprehensive income is as follows:
|  | 2017 |  |  | 2018 |  |  | 2019 |
|  | NT$000 |  |  | NT$000 |  |  | NT$000 |
Unrealized gain (loss) on valuation of financial assets at fair value through other comprehensive income |  |  | — |  |  |  | 17,005 |  |  |  | (7,016 | )
Remeasurement of defined benefit obligations |  |  | 8,642 |  |  |  | (11,992 | ) |  |  | 4,183 |
Impact of change in tax rate |  |  | — |  |  |  | (887 | ) |  |  | — |
|  |  | 8,642 |  |  |  | 4,126 |  |  |  | (2,833 | )
Reconciliation of Income Tax Expense and Accounting Profit Before Income Tax |
| b) | Reconciliation of income tax expense and the accounting profit:
|  | 2017 |  |  | 2018 |  |  | 2019 |
|  | NT$000 |  |  | NT$000 |  |  | NT$000 |
Tax calculated based on profit before tax and statutory tax rate |  |  | 566,649 |  |  |  | 356,488 |  |  |  | 606,917 |
Expenses disallowed by tax regulation |  |  | 10,185 |  |  |  | 14,689 |  |  |  | 3,055 |
Tax exempted (income) expenses by tax regulation |  |  | (256,788 | ) |  |  | 66,353 |  |  |  | (165,979 | )
Temporary differences not recognized as deferred tax assets |  |  | (85,168 | ) |  |  | (10,951 | ) |  |  | (608 | )
Prior year income tax under (over) estimation |  |  | 67,885 |  |  |  | 3,729 |  |  |  | (5,016 | )
Income tax on unappropriated retained earnings |  |  | 246,684 |  |  |  | 28,165 |  |  |  | 74,540 |
Impact of change in tax rate |  |  | — |  |  |  | (2,774 | ) |  |  | — |
Effect of different tax rates in countries in which the Group operates |  |  | 1,040 |  |  |  | 919 |  |  |  | 770 |
Income tax expense |  |  | 550,487 |  |  |  | 456,618 |  |  |  | 513,679 |
Details of Deferred Tax Assets (Liabilities) |
| c) | The amounts of deferred tax assets or liabilities resulting from temporary differences and investment tax credits are as follows:
|  | 2018 |
|  | January 1 |  |  | Effects on initial application of IFRS 9 and IFRS 15 |  |  | Recognized in profit or loss |  |  | Recognized in other comprehensive income |  |  | December 31 |
|  | NT$000 |  |  | NT$000 |  |  | NT$000 |  |  | NT$000 |  |  | NT$000 |
Deferred tax assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on inventories |  |  | 9,132 |  |  |  | (770 | ) |  |  | (1,130 | ) |  |  | — |  |  |  | 7,232 |
Property, plant and equipment |  |  | 55,494 |  |  |  | — |  |  |  | 8,689 |  |  |  | — |  |  |  | 64,183 |
Provisions |  |  | 21,643 |  |  |  | — |  |  |  | (9,247 | ) |  |  | — |  |  |  | 12,396 |
Deferred revenue |  |  | 39,485 |  |  |  | — |  |  |  | (5,329 | ) |  |  | — |  |  |  | 34,156 |
Net defined benefit liability |  |  | 78,451 |  |  |  | — |  |  |  | 7,889 |  |  |  | 14,403 |  |  |  | 100,743 |
Unrealized exchange losses |  |  | 8,167 |  |  |  | 144 |  |  |  | (4,736 | ) |  |  | — |  |  |  | 3,575 |
Investment tax credit |  |  | — |  |  |  | — |  |  |  | 4,420 |  |  |  | — |  |  |  | 4,420 |
Others |  |  | — |  |  |  | — |  |  |  | 11 |  |  |  | — |  |  |  | 11 |
Total |  |  | 212,372 |  |  |  | (626 | ) |  |  | 567 |  |  |  | 14,403 |  |  |  | 226,716 |
Deferred tax liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Property, plant and equipment |  |  | (174,293 | ) |  |  | — |  |  |  | (107,301 | ) |  |  | — |  |  |  | (281,594 | )
Contract assets |  |  | — |  |  |  | (8,067 | ) |  |  | 8,067 |  |  |  | — |  |  |  | — |
Financial assets at fair value through other comprehensive income |  |  | — |  |  |  | (8,636 | ) |  |  | — |  |  |  | (18,529 | ) |  |  | (27,165 | )
Total |  |  | (174,293 | ) |  |  | (16,703 | ) |  |  | (99,234 | ) |  |  | (18,529 | ) |  |  | (308,759 | )
Information presented on statements of financial position: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred tax assets |  |  | 212,372 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 226,716 |
Deferred tax liabilities |  |  | (174,293 | ) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (308,759 | )
|  | 2019 |
|  | January 1 |  |  | Recognized in profit or loss |  |  | Recognized in other comprehensive income |  |  | December 31 |
|  | NT$000 |  |  | NT$000 |  |  | NT$000 |  |  | NT$000 |
Deferred tax assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on inventories |  |  | 7,232 |  |  |  | 5,468 |  |  |  | — |  |  |  | 12,700 |
Property, plant and equipment |  |  | 64,183 |  |  |  | (25,515 | ) |  |  | — |  |  |  | 38,668 |
Provisions |  |  | 12,396 |  |  |  | (6,796 | ) |  |  | — |  |  |  | 5,600 |
Deferred revenue |  |  | 34,156 |  |  |  | (6,506 | ) |  |  | — |  |  |  | 27,650 |
Net defined benefit liability |  |  | 100,743 |  |  |  | (3,948 | ) |  |  | (4,183 | ) |  |  | 92,612 |
Unrealized exchange losses |  |  | 3,575 |  |  |  | 13,721 |  |  |  | — |  |  |  | 17,296 |
Investment tax credit |  |  | 4,420 |  |  |  | (4,420 | ) |  |  | — |  |  |  | — |
Others |  |  | 11 |  |  |  | 15 |  |  |  | — |  |  |  | 26 |
Total |  |  | 226,716 |  |  |  | (27,981 | ) |  |  | (4,183 | ) |  |  | 194,552 |
Deferred tax liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Property, plant and equipment |  |  | (281,594 | ) |  |  | (7,386 | ) |  |  | — |  |  |  | (288,980 | )
Financial assets at fair value through other comprehensive income |  |  | (27,165 | ) |  |  | — |  |  |  | 7,016 |  |  |  | (20,149 | )
Total |  |  | (308,759 | ) |  |  | (7,386 | ) |  |  | 7,016 |  |  |  | (309,129 | )
Information presented on statements of financial position |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred tax assets |  |  | 226,716 |  |  |  |  |  |  |  |  |  |  |  | 194,552 |
Deferred tax liabilities |  |  | (308,759 | ) |  |  |  |  |  |  |  |  |  |  | (309,129 | )

X
- Definition The disclosure of deferred taxes. [Refer: Deferred tax liabilities; Deferred tax assets] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 10 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_10_e&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_DisclosureOfDeferredTaxesExplanatory
Namespace Prefix: | ifrs-full_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of deferred tax charged to other comprehensive income. + References No definition available. + Details
Name: | imos_DisclosureOfDeferredTaxChargedToOtherComprehensiveIncomeExplanatory
Namespace Prefix: | imos_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of income tax (expense) benefit. + References No definition available. + Details
Name: | imos_DisclosureOfIncomeTaxExpenseBenefitExplanatory
Namespace Prefix: | imos_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of reconciliation of effective and applicable income tax expenses. + References No definition available. + Details
Name: | imos_DisclosureOfReconciliationOfEffectiveAndApplicableIncomeTaxExpensesExplanatory
Namespace Prefix: | imos_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Text block [abstract] + References No definition available. + Details
Name: | imos_TextBlockAbstract
Namespace Prefix: | imos_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration