Pension and Severance Plans (Korean Severance Plan) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Compensation Liability, Current and Noncurrent [Roll Forward]
Non-current portion of severance obligation	$ 152,673	$ 165,073
Korean Severance Plan [Member]
Deferred Compensation Liability, Current and Noncurrent [Roll Forward]
Balance	145,373	126,762	106,715
Provision of severance benefits	17,593	26,550	19,667
Severance payments	(10,160)	(10,402)	(8,520)
(Gain) loss on foreign currency	(5,926)	2,463	8,900
Balance	146,880	145,373	126,762
Payments remaining with the National Pension Fund	(219)	(241)	(249)
Korean Severance Plan [Member]
Deferred Compensation Liability, Current and Noncurrent [Roll Forward]
Pension and Other Postretirement and Postemployment Benefit Plans, Liabilities	146,661	145,132	126,513
Less current portion of accrued severance obligation (Note 13)	13,226	11,197	9,516
Non-current portion of severance obligation	$ 133,435	$ 133,935	$ 116,997
Minimum [Member] \| Korean Severance Plan [Member]
Restructuring Cost and Reserve [Line Items]
Accrued Severance Plan Minimum Service Period	1 year

Name:	amkr_DeferredCompensationLiabilityCurrentAndNoncurrentRollForward
Namespace Prefix:	amkr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Lump-sum payments related to termination of employment (employees and directors), based on length of service, seniority and average monthly wages at the time of termination, which is not related to restructurings, pension plans or other post retirement benefit plans. Severance benefits are estimated assuming all eligible employees were to terminate their employment at the balance sheet date.

+ References

No definition available.

+ Details

Name:	amkr_PaymentsForEmployeeSeverance
Namespace Prefix:	amkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Payments remaining with the Korean National Pension Fund.

+ References

No definition available.

+ Details

Name:	amkr_PaymentsRemainingWithLocalPensionFund
Namespace Prefix:	amkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Provision related to lump-sum payment upon termination of employment (employees and directors), based on length of service, seniority and average monthly wages at the time of termination, which is not related to restructurings, pension plans or other post retirement benefit plans. Severance benefits are estimated assuming all eligible employees were to terminate their employment at the balance sheet date.

+ References

No definition available.

+ Details

Name:	amkr_ProvisionOfSeveranceBenefits
Namespace Prefix:	amkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Foreign currency translation adjustments related to the transactions for lump-sum payment upon termination of employment (employees and directors), based on length of service, seniority and average monthly wages at the time of termination, which is not related to restructurings, pension plans or other post retirement benefit plans. Severance benefits are estimated assuming all eligible employees were to terminate their employment at the balance sheet date.

+ References

No definition available.

+ Details

Name:	amkr_SeveranceBenefitsTranslationAdjustments
Namespace Prefix:	amkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 710

-SubTopic 10

-Section 55

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6409961&loc=d3e20487-108367

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualRequisiteServicePeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for deferred compensation arrangements. Represents currently earned compensation under cash arrangements (such as a profit-sharing plan, rabbi trust, and employee contract--excluding equity-based arrangements) that is not actually paid until a later date.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The current liability recognized in the balance sheet that is associated with defined benefit pension plans and other postretirement and postemployment benefit plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2410-114920

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=21915240&loc=d3e1703-114919

+ Details

Name:	us-gaap_PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This represents the entire liability recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement and postemployment benefit plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.15)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2410-114920

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=21915240&loc=d3e1703-114919

+ Details

Name:	us-gaap_PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrentAndNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This represents the noncurrent liability recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement and postemployment benefit plans.

+ References

+ Details

Name:	us-gaap_PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_RestructuringCostAndReserveLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	amkr_OtherDeferredCashCompensationAxis=amkr_KoreanSeverancePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=amkr_KoreanSeverancePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: