Commitments and Contingencies (Details) (USD $)	0 Months Ended		1 Months Ended			3 Months Ended	1 Months Ended		0 Months Ended	12 Months Ended
	Sep. 10, 2014 patent	Aug. 31, 2008 item	Oct. 31, 2011	Sep. 30, 2011 item	Aug. 31, 2008 item	Mar. 31, 2015 item	Apr. 30, 2010 item	Sep. 30, 2004 sqft	Feb. 05, 2013 item sqft	Dec. 31, 2011 sqft	May 01, 2011	Nov. 30, 2005 sqft
Operating leases disclosures
2016						$ 9,189,000
2017						4,924,000
Operating lease commitments
April 1, 2015 through December 31, 2015						8,406,000
2016						9,189,000
2017						4,924,000
2018						1,608,000
Total future minimum lease payments						24,127,000
Legal Contingencies
Number of patents infringed				2	4
Orange Book-listed patents for Copaxone		7			7
Orange Book-listed patents for 40 mg/ml Copaxone	2
Number of patents certifications that generic manufacturer's ANDA must include						1
Additional Number of patents infringed		2
Non Orange Book-listed patent with September 1,2015 expiration						1
Amount of security bond required to be posted by company and Sandoz in connection with the litigation			100,000,000
Maximum amount of security bond for which the entity shall be responsible in the event of loss of case						35,000,000
West Kendall Sublease
Operating leases disclosures
Square feet of office and laboratory space leased								53,323				25,131
Initial lease term								80 months
Number of additional lease terms exercised							1
Extended lease term							48 months
Increase in annual lease payments during the extension term											1,200,000
Annual rental payments due under the sublease						4,800,000
320 Bent Sublease
Operating leases disclosures
Square feet of office and laboratory space leased									104,678	68,575
Initial lease term										18 months
Extended lease term									1 year
Annual rental payments due under the sublease										2,300,000
2015									6,100,000
2016									6,200,000
2017									6,300,000
Tenant improvement allowance									700,000
Number of times for which extension of lease term is available									2
Additional number of times extension of lease term is available									2
Additional extended lease term									5 years
Operating lease commitments
2016									6,200,000
2017									$ 6,300,000