Debt Instrument Face Amount Related Party

No definition available.

Name:	amkr_DebtInstrumentFaceAmountRelatedParty
Namespace Prefix:	amkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Step Down Provision

+ References

No definition available.

+ Details

Name:	amkr_LineOfCreditFacilityStepDownProvision
Namespace Prefix:	amkr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the time period between step downs under the step down provision for a line of credit.

+ References

No definition available.

+ Details

Name:	amkr_LineofCreditFacilityStepDownProvisionStepDownPeriod
Namespace Prefix:	amkr_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

Amount of the required periodic payments applied to principal.

+ 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 210.5-02.22)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

Name:	us-gaap_DebtInstrumentPeriodicPaymentPrincipal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ 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 210.5-02.22(b))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Subparagraph b

-Article 5

+ Details

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

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ 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 210.5-02.19(b),22(b))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ 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 210.5-02.19(b),22(b))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(f))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph f

-Article 4

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=amkr_SubsidiaryTermLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt (Details) (USD $)	3 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended
Debt (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Feb. 28, 2015	Sep. 30, 2012	Apr. 30, 2015	Apr. 30, 2013	Mar. 31, 2013	Nov. 30, 2012	Jun. 30, 2012
Debt Instrument [Line Items]
Borrowings under revolving credit facilities	$ 30,000,000us-gaap_ProceedsFromLinesOfCredit	$ 0us-gaap_ProceedsFromLinesOfCredit
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, LIBOR plus 3.70%, due June 2016 (2)
Debt Instrument [Line Items]
Credit facility, borrowing capacity						150,000,000.0
Debt Instrument, Basis Spread on Variable Rate	3.70%
Debt, interest rate description	LIBOR plus 3.70%
Total effective rate (percentage)	3.97%
Current borrowing capacity	80,000,000.0
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, foreign currency funding-linked base rate plus 1.80%, due March 2017 (3)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.80%
Debt, interest rate description	foreign currency funding-linked base rate plus 1.80%
Debt Instrument, Unused Borrowing Capacity, Amount		80,000,000.0
Total effective rate (percentage)	3.08%
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, LIBOR plus 3.70%, due July 2017 (1)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.70%
Debt, interest rate description	LIBOR plus 3.70%
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, foreign currency funding-linked base rate plus 1.75%, due September 2017 (4)
Debt Instrument [Line Items]
Credit facility, borrowing capacity							150,000,000.0
Debt Instrument, Basis Spread on Variable Rate	1.75%
Debt Instrument, Periodic Payment, Principal	5,000,000.0
Debt, interest rate description	foreign currency funding-linked base rate plus 1.75%
Total effective rate (percentage)	3.20%
Current borrowing capacity	140,000,000.0
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, LIBOR plus 3.70%, due December 2019 (5)
Debt Instrument [Line Items]
Credit facility, borrowing capacity								100,000,000
Debt Instrument, Basis Spread on Variable Rate	3.70%
Debt, interest rate description	LIBOR plus 3.70%
Total effective rate (percentage)	3.94%
Senior notes (Level 1) \| 7.375% Senior notes, due May 2018
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.375%
Senior notes (Level 1) \| 6.625% Senior notes, due June 2021, $75 million related party
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.625%
Face amount for related party	75,000,000
Senior notes (Level 1) \| 6.375% Senior notes, due October 2022
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.375%
Revolving Credit Facility [Member] \| Line of Credit [Member] \| $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019
Debt Instrument [Line Items]
Credit facility, borrowing capacity	200,000,000
Debt, interest rate description	LIBOR plus 1.25%-1.75%
Revolving Credit Facility [Member] \| Line of Credit [Member] \| $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.25%
Revolving Credit Facility [Member] \| Line of Credit [Member] \| $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Revolving Credit Facility [Member] \| Line of Credit [Member] \| KOREA, REPUBLIC OF \| Revolving credit facility due June 2016 [Member]
Debt Instrument [Line Items]
Credit facility, borrowing capacity	41,000,000								41,000,000
Debt Instrument, Basis Spread on Variable Rate	1.60%
Debt, interest rate description	foreign currency funding-linked base rate plus 1.60%
Borrowings under revolving credit facilities			30,000,000
Total effective rate (percentage)	3.05%
Current borrowing capacity	11,000,000
Revolving Credit Facility [Member] \| Line of Credit [Member] \| TAIWAN, PROVINCE OF CHINA \| Revolving credit facility, TAIFX plus a bank-determined spread, due April 2015 (Taiwan) (6)
Debt Instrument [Line Items]
Credit facility, borrowing capacity	44,000,000.0
Debt, interest rate description	TAIFX plus a bank-determined spread
Current borrowing capacity	19,000,000
Line of Credit Facility, Step Down Provision	$ 5,000,000.0
Line of Credit Facility, Step Down Provision, Step Down Period				6 months
Subsequent Event [Member] \| Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, LIBOR plus 3.70%, due December 2019 (5)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate					2.70%