XML 181 R160.htm IDEA: XBRL DOCUMENT v3.24.1.u1

Segment Information - Financial Segment Information for Operating Segments (Detail) $ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 TWD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 TWD ($)	Dec. 31, 2021 TWD ($)
Revenue
Revenue	$ 21,356,228	$ 697,460	$ 23,517,064	$ 27,400,035
Operating profit (loss)	1,908,452	62,327	3,216,679	5,562,389
Depreciation expenses	(4,779,333)		(4,751,902)	(4,634,112)
Share of profit of associates	219,891	7,182	453,715	625,733
Interest income	193,189	$ 6,309	57,199	9,980
Interest expense	(265,957)		(142,439)	(120,998)
Purchase of property, plant and equipment	3,228,471		4,918,482	6,552,702
External [member]
Revenue
Revenue	21,356,228		23,517,064	27,400,035
Operating segments [member] | Testing [member]
Revenue
Revenue	4,394,726		5,243,997	5,899,600
Operating profit (loss)	514,707		1,253,477	1,814,021
Depreciation expenses	(1,065,689)		(1,042,455)	(921,999)
Purchase of property, plant and equipment	749,158		1,086,682	1,841,359
Operating segments [member] | Testing [member] | External [member]
Revenue
Revenue	4,394,726		5,243,997	5,899,600
Operating segments [member] | Assembly [member]
Revenue
Revenue	4,629,430		6,705,898	7,963,714
Operating profit (loss)	(1,180,481)		(93,585)	857,304
Depreciation expenses	(722,462)		(694,835)	(576,138)
Purchase of property, plant and equipment	568,289		957,790	1,553,475
Operating segments [member] | Assembly [member] | External [member]
Revenue
Revenue	4,629,430		6,705,898	7,963,714
Operating segments [member] | LCDD [member]
Revenue
Revenue	7,821,640		7,288,642	8,211,099
Operating profit (loss)	2,058,285		1,795,741	2,336,394
Depreciation expenses	(2,547,253)		(2,505,297)	(2,579,150)
Purchase of property, plant and equipment	1,756,590		2,677,489	2,748,697
Operating segments [member] | LCDD [member] | External [member]
Revenue
Revenue	7,821,640		7,288,642	8,211,099
Operating segments [member] | Bumping [member]
Revenue
Revenue	4,510,432		4,278,527	5,325,622
Operating profit (loss)	522,386		268,159	561,642
Depreciation expenses	(435,709)		(500,863)	(549,020)
Purchase of property, plant and equipment	152,908		196,521	408,751
Operating segments [member] | Bumping [member] | External [member]
Revenue
Revenue	4,510,432		4,278,527	5,325,622
Operating segments [member] | Others [member]
Revenue
Revenue	59,481		50,600	43,808
Operating profit (loss)	(6,194)		(6,821)	(6,987)
Depreciation expenses	(8,220)		(8,452)	(7,805)
Share of profit of associates	420,393		884,555	1,211,177
Interest income	193,189		57,199	9,980
Interest expense	(265,957)		(142,439)	(120,998)
Purchase of property, plant and equipment	1,526			420
Operating segments [member] | Others [member] | Intersegment [member]
Revenue
Revenue	59,481		50,600	43,808
Elimination [member]
Revenue
Revenue	(59,481)		(50,600)	(43,808)
Operating profit (loss)	(251)		(292)	15
Share of profit of associates	(200,502)		(430,840)	585,444
Elimination [member] | Intersegment [member]
Revenue
Revenue	$ (59,481)		$ (50,600)	$ (43,808)

X

- Definition

The amount of additions to property, plant and equipment other than those acquired through business combinations. [Refer: Business combinations [member]; Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2023-01-01
-Paragraph 73
-Subparagraph e
-Clause i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2023-en-r&anchor=para_73_e_i&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipment
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of depreciation expense. Depreciation is the systematic allocation of depreciable amounts of tangible assets over their useful lives.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_DepreciationExpense
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of expense arising from interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 28
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_28_e&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2023-01-01
-Paragraph B13
-Subparagraph f
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2023-en-r&anchor=para_B13_f&doctype=Appendix&subtype=B
-URIDate 2023-03-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 23
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_23_d&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_InterestExpense
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The profit (loss) from operating activities of the entity. [Refer: Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 32
-IssueDate 2023-01-01
-Paragraph IE33
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=32&code=ifrs-tx-2023-en-r&anchor=para_IE33&doctype=Illustrative%20Examples
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 85
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_85&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_ProfitLossFromOperatingActivities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 28
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_28_a&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 23
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_23_a&doctype=Standard
-URIDate 2023-03-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 32
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_32&doctype=Standard
-URIDate 2023-03-23

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 5
-IssueDate 2023-01-01
-Paragraph 33
-Subparagraph b
-Clause i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2023-en-r&anchor=para_33_b_i&doctype=Standard
-URIDate 2023-03-23

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 33
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_33_a&doctype=Standard
-URIDate 2023-03-23

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 34
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_34&doctype=Standard
-URIDate 2023-03-23

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2023-01-01
-Paragraph B12
-Subparagraph b
-Clause v
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2023-en-r&anchor=para_B12_b_v&doctype=Appendix&subtype=B
-URIDate 2023-03-23

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 12
-IssueDate 2023-01-01
-Paragraph B10
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2023-en-r&anchor=para_B10_b&doctype=Appendix&subtype=B
-URIDate 2023-03-23

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 82
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_82_a&doctype=Standard
-URIDate 2023-03-23

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 103
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_103&doctype=Standard
-URIDate 2023-03-23

Reference 11: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 102
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_102&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_Revenue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	ifrs-full_RevenueAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of income arising from interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 23
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_23_c&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 28
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_28_e&doctype=Standard
-URIDate 2023-03-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2023-01-01
-Paragraph B13
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2023-en-r&anchor=para_B13_e&doctype=Appendix&subtype=B
-URIDate 2023-03-23

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_RevenueFromInterest
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- 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 2023-01-01
-Paragraph 28
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_28_e&doctype=Standard
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2023-01-01
-Paragraph 23
-Subparagraph g
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_23_g&doctype=Standard
-URIDate 2023-03-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 82
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_82_c&doctype=Standard
-URIDate 2023-03-23

+ Details

Name:	ifrs-full_ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	ifrs-full_TypesOfCustomersAxis=imos_ExternalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentConsolidationItemsAxis=ifrs-full_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentsAxis=imos_TestingSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentsAxis=imos_AssemblySegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentsAxis=imos_LCDDSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentsAxis=imos_BumpingSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentsAxis=ifrs-full_AllOtherSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_TypesOfCustomersAxis=imos_IntersegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_SegmentConsolidationItemsAxis=ifrs-full_EliminationOfIntersegmentAmountsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: