Nature of Business - Overview (Details)	3 Months Ended
Mar. 31, 2017
Overview
Treatment of ulcerative	2 years

Duration for which the company is appointed to promote the approved treatment for ulcerative proctitis.

No definition available.

Name:	irwd_DurationForWhichCompanyIsAppointedToPromoteApprovedTreatmentForUlcerativeProctitis
Namespace Prefix:	irwd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration