Line of Credit Facility, Step Down Provision

No definition available.

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

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Balance Type:	na
Period Type:	duration

- Definition

Payments of Debt Exchange Costs

+ References

No definition available.

+ Details

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

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

+ Details

Name:	us-gaap_DebtConversionOriginalDebtAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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 price per share of the conversion feature embedded in the debt instrument.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ 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 FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

- Definition

Maximum contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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

- Definition

Minimum 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)(2))

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

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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

- Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
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

Description of the credit facility's borrowing capacity including discussion of how the borrowing capacity is determined (for example, borrowing capacity based on the amount of current assets).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

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

- 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

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
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Debt (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	12 Months Ended			1 Months Ended		3 Months Ended	1 Months Ended	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 30, 2014	Jun. 30, 2013	Dec. 31, 2014	Jan. 31, 2012	Sep. 30, 2012	Apr. 30, 2009	Mar. 31, 2013	Mar. 31, 2014	Apr. 30, 2013	Sep. 30, 2014	Jun. 30, 2012
Debt Instruments [Abstract]
Payments of Debt Exchange Costs	$ 0amkr_PaymentsofDebtExchangeCosts	$ 11,619,000amkr_PaymentsofDebtExchangeCosts	$ 0amkr_PaymentsofDebtExchangeCosts
Letter of Credit [Member]
Debt Instruments [Abstract]
Credit facility, borrowing capacity	25,000,000					25,000,000
Convertible Subordinated Debt [Member] \| 6.0% Convertible senior subordinated notes, due April 2014 (2)
Debt Instruments [Abstract]
Debt Instrument, Face Amount									250,000,000
Interest rate	6.00%					6.00%			6.00%
Debt Instrument, Convertible, Conversion Price									$ 3.02
Debt Conversion, Converted Instrument, Shares Issued				18.6	64.0
Payments of Debt Exchange Costs					11,600,000
Common stock issuance for conversion of related party 6.25% convertible subordinated notes				56,400,000	193,700,000
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, foreign currency funding-linked base rate plus 1.75%, due September 2017 (7)
Debt Instruments [Abstract]
Credit facility, borrowing capacity										150,000,000
Debt Instrument, Basis Spread on Variable Rate	1.75%
Debt Instrument, Periodic Payment, Principal						5,000,000
Line of Credit Facility, Current Borrowing Capacity	140,000,000					140,000,000
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, LIBOR plus 3.70%, due July 2017 (6)
Debt Instruments [Abstract]
Debt Instrument, Basis Spread on Variable Rate	3.70%
Interest rate	3.70%					3.70%
Debt Instrument Term	5 years
Repayments of Debt				60,000,000
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, foreign currency funding-linked base rate plus 2.00%, due March 2017 (5)
Debt Instruments [Abstract]
Debt Instrument, Basis Spread on Variable Rate	2.00%
Debt Instrument, Unused Borrowing Capacity, Amount											80,000,000
Interest rate	1.80%					1.80%
Subsidiary Term Loans [Member] \| KOREA, REPUBLIC OF \| Term loan, LIBOR plus 3.70%, due June 2016 (4)
Debt Instruments [Abstract]
Credit facility, borrowing capacity												150,000,000
Debt Instrument, Basis Spread on Variable Rate	3.70%
Line of Credit Facility, Current Borrowing Capacity	80,000,000					80,000,000
Line of Credit [Member] \| Revolving Credit Facility [Member] \| $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 (1)
Debt Instruments [Abstract]
Credit facility, borrowing capacity	200,000,000					200,000,000							150,000,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum						1.25%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum						1.75%
Line of Credit Facility, Borrowing Capacity, Description	borrowing base for the revolving credit facility is based on the amount of our eligible accounts receivable, which exceeded $200.0 million
Line of Credit [Member] \| Revolving Credit Facility [Member] \| KOREA, REPUBLIC OF
Debt Instruments [Abstract]
Debt Instrument Term							12 months
Line of Credit [Member] \| Revolving Credit Facility [Member] \| KOREA, REPUBLIC OF \| $41 million revolving credit facility, foreign currency funding-linked base rate plus 2.00%, due June 2016 (3)
Debt Instruments [Abstract]
Credit facility, borrowing capacity	41,000,000					41,000,000								41,000,000
Debt Instrument, Basis Spread on Variable Rate	2.00%
Line of Credit Facility, Current Borrowing Capacity	41,000,000					41,000,000
Line of Credit [Member] \| Revolving Credit Facility [Member] \| TAIWAN, PROVINCE OF CHINA \| Revolving credit facility, TAIFX plus a bank-determined spread, due April 2015 (Taiwan) (8)
Debt Instruments [Abstract]
Credit facility, borrowing capacity	44,000,000					44,000,000
Line of Credit Facility, Current Borrowing Capacity	19,000,000					19,000,000
Step down provision	$ 5,000,000					$ 5,000,000
Line of Credit Facility, Step Down Provision, Step Down Period								6 months
Minimum [Member] \| Line of Credit [Member] \| Revolving Credit Facility [Member] \| $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 (1)
Debt Instruments [Abstract]
Debt Instrument, Basis Spread on Variable Rate						0.00%
Interest rate	1.25%					1.25%
Maximum [Member] \| Line of Credit [Member] \| Revolving Credit Facility [Member] \| $200 million revolving credit facility, LIBOR plus 1.25%-1.75%, due December 2019 (1)
Debt Instruments [Abstract]
Debt Instrument, Basis Spread on Variable Rate						0.50%
Interest rate	1.75%					1.75%