Commitments and Contingencies (Details) $ in Thousands				1 Months Ended					9 Months Ended	12 Months Ended
	Sep. 10, 2014 patent	Feb. 05, 2013 USD ($) ft² item	Aug. 31, 2008 item	Oct. 31, 2011 USD ($)	Sep. 30, 2011 item	Apr. 30, 2010 item	Aug. 31, 2008 item	Sep. 30, 2004 ft²	Sep. 30, 2015 USD ($) item	Dec. 31, 2011 USD ($) ft²	May. 01, 2011 USD ($)	Nov. 30, 2005 ft²
Operating leases disclosures
2016									$ 9,189
2017									4,924
Operating lease commitments
October 1, 2015 through December 31, 2015									2,820
2016									9,189
2017									4,924
2018									1,608
Total future minimum lease payments									$ 18,541
Legal Contingencies
Number of patents infringed | item					2		4
Orange Book-listed patents for Copaxone | item			7				7
Orange Book-listed patents for 40 mg/ml Copaxone | patent	2
Number of patents certifications that generic manufacturer's ANDA must include | item									1
Additional Number of patents infringed | item			2
Non Orange Book-listed patent with September 1,2015 expiration | item									1
Amount of security bond required to be posted by company and Sandoz in connection with the litigation				$ 100,000
Maximum amount of security bond for which the entity shall be responsible in the event of loss of case									$ 35,000
West Kendall Sublease
Operating leases disclosures
Square feet of office and laboratory space leased | ft²								53,323				25,131
Initial lease term								80 months
Number of additional lease terms exercised | item						1
Extended lease term						48 months
Increase in annual lease payments during the extension term											$ 1,200
Annual rental payments due under the sublease									$ 4,800
320 Bent Sublease
Operating leases disclosures
Square feet of office and laboratory space leased | ft²		104,678								68,575
Initial lease term										18 months
Extended lease term		1 year
Annual rental payments due under the sublease										$ 2,300
2015		$ 6,100
2016		6,200
2017		6,300
Tenant improvement allowance		$ 700
Number of times for which extension of lease term is available | item		2
Additional number of times extension of lease term is available | item		2
Additional extended lease term		5 years
Operating lease commitments
2016		$ 6,200
2017		$ 6,300