Collaboration and License Agreements (Details) (USD $)	3 Months Ended		15 Months Ended	0 Months Ended	1 Months Ended			12 Months Ended
	Mar. 31, 2015 item	Mar. 31, 2014	Sep. 30, 2011 item	Apr. 16, 2015	Jul. 31, 2006	Feb. 28, 2015	Oct. 31, 2014	Dec. 31, 2013
Collaboration revenues:
Product revenue	$ 2,722,000	$ 4,812,000
Research and development revenue
Amortization of upfront payments	1,686,000	1,042,000
Research and development services and external costs	4,154,000	4,931,000
Total research and development revenue	5,840,000	5,973,000
Total collaboration revenue	8,562,000	10,785,000
Operating expenses:
Research and Development Expense	787,000	5,132,000
General and Administrative Expense	593,000	182,000
Total Operating expenses	1,380,000	5,314,000
Reduction in number of significant deliverables identified in arrangement	1
2003 Sandoz Collaboration
Collaboration revenues:
Product revenue	2,722,000	4,812,000
Research and development revenue
Research and development services and external costs	251,000	323,000
Total research and development revenue	251,000	323,000
Total collaboration revenue	2,973,000	5,135,000
Operating expenses:
Research and Development Expense	31,000	19,000
General and Administrative Expense	110,000	9,000
Total Operating expenses	141,000	28,000
Percentage of contractual profits earned under collaborative arrangement	45.00%
Percentage of royalty for net sales up to pre-defined sales threshold	10.00%
Percentage of royalty for net sales above pre-defined sales threshold	12.00%
Maximum percentage of reduction of profit-share, royalty and milestone payments from Sandoz at each quarter	50.00%
Number of significant deliverables identified in arrangement	2
Number of third-party competitors			0
Second Sandoz Collaboration Agreement
Research and development revenue
Amortization of upfront payments		239,000
Research and development services and external costs	684,000	190,000
Total research and development revenue	684,000	429,000
Total collaboration revenue	684,000	429,000
Operating expenses:
Research and Development Expense	148,000	296,000
General and Administrative Expense	77,000	143,000
Total Operating expenses	225,000	439,000
Number of shares sold					4,708,679
Per share price of shares sold					$ 15.93
Closing price of the company's common stock on the NASDAQ Global Market (in dollars per share)					$ 13.05
Aggregate purchase price of shares sold					75,000,000
Premium paid					13,600,000
Regulatory milestone payment earned				10,000,000
Second Sandoz Collaboration Agreement | Maximum
Operating expenses:
Milestone payments possible per agreement	153,000,000
Regulatory milestone payment possible per agreement	10,000,000
Sales-based and commercial milestone payments possible per agreement	120,000,000.00000
U.S.-based milestone payments possible per agreement	23,000,000.00000
Second Sandoz Collaboration Agreement | Novartis Pharma AG
Operating expenses:
Percentage of contractual profits earned under collaborative arrangement	50.00%
Baxter Agreement
Research and development revenue
Amortization of upfront payments	1,686,000	803,000
Research and development services and external costs	3,219,000	4,418,000
Total research and development revenue	4,905,000	5,221,000
Total collaboration revenue	4,905,000	5,221,000
Operating expenses:
Research and Development Expense	608,000	4,817,000
General and Administrative Expense	406,000	30,000
Total Operating expenses	1,014,000	4,847,000
Upfront payment paid by Baxter to the company	33,000,000
Number of additional biosimilars under the agreement	4
Option payments agreed to be paid by Baxter with respect to additional product candidates	12,000,000
Option payment which the entity is no longer eligible to receive	7,000,000
Remaining payment obligation	0
Baxter Agreement | Accounting Standards Update 2009 to 2013 Member
Operating expenses:
Number of significant deliverables identified in arrangement	7
Current number of significant deliverables identified in arrangement	6
Total arrangement consideration	61,000,000
Portion of arrangement consideration allocated to the first initial product license	10,300,000
Portion of arrangement consideration allocated to each of the four additional product licenses	10,300,000
Portion of arrangement consideration allocated to the second initial product license	9,400,000
Portion of arrangement consideration allocated to the joint steering committee unit of accounting	114,000
Reduction in total arrangement consideration							7,000,000	7,000,000
Portion of revised arrangement consideration reallocated to the remaining deliverables						40,000,000	61,000,000	54,000,000
Portion of revised arrangement consideration allocated to the first initial product license as a result of termination of product						39,600,000	12,400,000	11,000,000
Portion of revised arrangement consideration allocated to each of the three additional product licenses as a result of termination of product						400,000	12,400,000	11,000,000
Portion of revised arrangement consideration allocated to the second initial product license as a result of termination of product							11,300,000	10,000,000
Portion of revised arrangement consideration allocated to the joint steering committee unit of accounting as a result of termination of product							137,000,000,000	122,000
Decrease in portion of revised arrangement consideration reallocated to the remaining deliverables	40,000,000
Number of follow-on biologic products for development and product licenses	2
Number of additional follow-on biologic products for development and product licenses	4
Deferred revenue	29,300,000
Deferred revenue included in current liabilities	9,800,000
Deferred revenue included in non-current liabilities	19,500,000
Number of follow-on biologic products for research and development services	2
Number of additional follow-on biologic products for research and development services	4
Number of vendors selling similar, competing products on a stand-alone basis	0
Number of license agreements	6
Baxter Agreement | Maximum
Operating expenses:
Aggregate regulatory milestone to be paid by Baxter	$ (50,000,000)