Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage

No definition available.

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- Definition

Represents the amount of domestic unrestricted cash and cash equivalents that can be excluded from the ratio calculation.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Minimum Principal Amount Of Convertible Notes Outstanding That Triggers Maturity Acceleration.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Minimum Principal Amount Of Term Loans Outstanding That Triggers Maturity Acceleration.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Percentage of equity interests in direct foreign subsidiaries pledged as collateral for borrowing.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of equity interests in domestic subsidiaries pledged as collateral for borrowing.

+ References

No definition available.

+ Details

Name:	amag_DebtInstrumentPledgePercentageOfEquityInterestsInDomesticSubsidiaries
Namespace Prefix:	amag_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Prepayment Premium, Percentage Of Principal Amount Of Prepayment If Prepayment Made After 12 Months But Before 24 Months From Closing Date

+ References

No definition available.

+ Details

Name:	amag_PrepaymentPremiumPercentageOfPrincipalAmountOfPrepaymentIfPrepaymentMadeAfter12MonthsFromClosingDateButBefore24MonthsFromClosingDate
Namespace Prefix:	amag_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Prepayment Premium, Percentage Of Principal Amount Of Prepayment If Prepayment Made Before 12 Months From Closing Date

+ References

No definition available.

+ Details

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Namespace Prefix:	amag_
Data Type:	num:percentItemType
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- 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

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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

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Balance Type:	na
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- Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of the required periodic payments including both interest and principal payments.

+ 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

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

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Balance Type:	debit
Period Type:	duration

- Definition

Including the current and noncurrent portions, aggregate carrying value as of the balance sheet date of loans payable (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16(a)(2))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

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)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20, 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

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

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Indebtedness divided by net capital.

+ References

No definition available.

+ Details

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Debt (Details 2) (USD $)	3 Months Ended
Debt (Details 2) (USD $)	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2014	Nov. 30, 2014	Nov. 12, 2014
Debt
Interest rate (as a percent)		2.50%	2.50%
Long-term Debt, Total		$ 281,904,000us-gaap_LongTermDebt	$ 293,905,000us-gaap_LongTermDebt
Term Loan
Debt
Principal amount of debt issued				340,000,000
Term Loan \| Credit Facility
Debt
Principal amount of debt issued					340,000,000
Loans Payable		320,200,000
Installment payment amount	12,750,000	8,500,000
Prepayment Premium, Percentage Of Principal Amount Of Prepayment If Prepayment Made Before 12 Months From Closing Date		2.00%
Prepayment Premium, Percentage Of Principal Amount Of Prepayment If Prepayment Made After 12 Months But Before 24 Months From Closing Date		1.00%
Percentage of equity interests in domestic subsidiaries pledged as collateral for borrowing (as a percent)		100.00%
Percentage of equity interests in direct foreign subsidiaries pledged as collateral for borrowing (as a percent)		65.00%
Term Loan \| Credit Facility \| Excess Cash Flows, Range One
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage		75.00%
Total Net Leverage Ratio		2.00
Term Loan \| Credit Facility \| Excess Cash Flows, Range Two
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage		50.00%
Total Net Leverage Ratio		1.00
Term Loan \| Credit Facility \| Excess Cash Flows, Range Three
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage		25.00%
Total Net Leverage Ratio		0.50
Term Loan \| Credit Facility \| Excess Cash Flows, Range Four
Debt
Annual Mandatory Prepayment Of Term Loans From Excess Cash Flows Range Percentage		0.00%
Term Loan \| Credit Facility \| Forecast
Debt
Minimum Principal Amount Of Convertible Notes Outstanding That Triggers Maturity Acceleration		25,000,000
Minimum Principal Amount Of Term Loans Outstanding That Triggers Maturity Acceleration		50,000,000
Term Loan \| Maximum \| Credit Facility
Debt
Cash netted from ratio calculation		$ 25,000,000
Term Loan \| Maximum \| Credit Facility \| March 30, 2015
Debt
Total Net Leverage Ratio		4.60
Term Loan \| Maximum \| Credit Facility \| September 30, 2017
Debt
Total Net Leverage Ratio		1.00