The company's share of the net profit (loss) from the commercial sale of a product under a collaboration agreement.

No definition available.

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

- Definition

Represents the percentage of net loss from commercialization.

+ References

No definition available.

+ Details

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Namespace Prefix:	irwd_
Data Type:	num:percentItemType
Balance Type:	na
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- Definition

Represents the percentage of net profit from commercialization.

+ References

No definition available.

+ Details

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Namespace Prefix:	irwd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount represents 50% of product net sales as well as cost of revenue and selling and marketing cost-sharing settlement payments to the company from its collaboration partner.

+ References

No definition available.

+ Details

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

- Definition

Represents the revenue recognized from the sale of linaclotide API.

+ References

No definition available.

+ Details

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

- Definition

Represents the revenue recognized in royalty payments.

+ References

No definition available.

+ Details

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

- Definition

The royalty percentages to be applied per license agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	irwd_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the cumulative amount of license fees and milestone payments received to date.

+ References

No definition available.

+ Details

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Namespace Prefix:	irwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount to be received by the company upon completion of milestone.

+ References

No definition available.

+ Details

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Namespace Prefix:	irwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents net cost sharing offset amounts related to collaborative arrangement where a cost sharing agreement exists for research and development expenses. Amounts may net to either a reduction of expense, or may net to increased expense.

+ References

No definition available.

+ Details

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

- Definition

Represents the total number of milestone payments to be received once all milestones have been achieved.

+ References

No definition available.

+ Details

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Namespace Prefix:	irwd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Proceeds from issuance of capital stock which provides for a specific dividend that is paid to the shareholders before any dividends to common stockholders and which takes precedence over common stockholders in the event of liquidation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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

- Definition

The amount of consideration recognized during the period for the milestone or milestones.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 28
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=68058744&loc=SL6892177-166501

+ Details

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

- Definition

The aggregate total amount of expenses directly related to the marketing or selling of products or services.

+ References

No definition available.

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=us-gaap_CollaborativeArrangementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=us-gaap_CollaborativeArrangementProductAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	irwd_AchievementOfMilestoneAxis=irwd_DevelopmentMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	irwd_AchievementOfMilestoneAxis=irwd_CommercializationMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
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- Details

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Collaboration, License, Co-Promotion and Other Commercial Agreements - North America (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Sep. 30, 2007	Mar. 31, 2017 USD ($) item	Mar. 31, 2016 USD ($)
AstraZeneca \| Licensing agreement
Collaboration, License and Co-Promotion Agreements
Royalty percentage per agreement		single digits
North America \| Collaborative arrangement
Collaboration, License and Co-Promotion Agreements
Revenue recognized from sale of API		$ 0	$ 3,000
North America \| Allergan \| Product related collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Equity investment in the entity's capital stock		25,000
Net cost sharing offset or incremental expense related to research and development expense		400	2,000
North America \| Allergan \| Product related collaborative arrangements \| Development milestones
Collaboration, License and Co-Promotion Agreements
Cumulative license fees and development milestone payments received		$ 205,000
Number of milestone payments \| item		6
North America \| Allergan \| Product related collaborative arrangements \| Commercialization milestone
Collaboration, License and Co-Promotion Agreements
Percentage of net profit from commercialization		50.00%
Percentage of net loss from commercialization		50.00%
North America \| Future payments \| Product related collaborative arrangements \| Maximum \| Sales milestones
Collaboration, License and Co-Promotion Agreements
Milestone payment to be received by company upon milestone achievement		$ 100,000
U.S. \| Allergan \| Collaborative arrangement
Collaboration, License and Co-Promotion Agreements
Collaborative arrangements revenue related to sales of LINZESS in the U.S.		49,452	46,647
Revenue recognized from sale of API			3,017
Royalty revenue		499	309
Total collaborative arrangements revenue		49,951	49,973
U.S. \| Allergan \| Product related collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Collaborative arrangements revenue related to sales of LINZESS in the U.S.		49,452	46,647
Selling, general and administrative costs incurred by the Company		(11,109)	(9,153)
The Company's share of net profit (loss)		38,343	37,494
Canada and Mexico \| Allergan \| Product related collaborative arrangements
Collaboration, License and Co-Promotion Agreements
Royalty percentage per agreement	mid-teens
Royalty revenue		$ 500	$ 300