Annual report pursuant to Section 13 and 15(d)

Significant Strategic Drug Development Collaborations - Additional Information (Detail)

Significant Strategic Drug Development Collaborations - Additional Information (Detail)		1 Months Ended	12 Months Ended		174 Months Ended
	Jan. 23, 2014 shares	Jan. 30, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($) Product shares	Dec. 31, 2011 USD ($)
Subsequent Event [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Company issued new shares of common stock, Shares \| shares	132,545,504
Baxter Healthcare Sa And Baxter Healthcare Corporation [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development service fees recognized as revenue			$ 0	$ 0	$ 5,000,000
Supply agreement amended period			2010-09
Research and development recognized as revenue			$ 1,000,000	0	$ 3,000,000
Royalties expiration period			10 years
Royalties expiration description			The Company's right to receive these royalties in any particular country will expire upon the later of ten years after the first commercial sale of the product in that country or the expiration of patent rights in that particular country.
Agreement amended period			2014-01
Baxter Healthcare Sa And Baxter Healthcare Corporation [Member] \| Subsequent Event [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Company issued new shares of common stock value		$ 10,000,000
Baxter Healthcare Sa And Baxter Healthcare Corporation [Member] \| Scenario Forecast [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Development receipts			$ 18,000,000
Regulatory receipts			16,000,000
Sales target receipts			$ 66,000,000
Serum Institute Of India Limited [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Company issued new shares of common stock value				$ 1,100,000
Share ownership percentage			10.60%	10.60%
Description and terms of license and arrangements			In the period from 2004 through 2011, the Company entered into and amended certain license and supply agreements with Serum Institute. The original license agreement with Serum Institute was a collaborative Development and Manufacturing Arrangement ("DMA") to develop agreed upon potential commercial product candidates using the Company's PolyXen technology.
Company issued new shares of common stock, Shares \| shares				2,880,000
In-process research and development expense				$ 1,100,000
Number of potential commercial product \| Product				14
License amendment description			Following the 2011 amendment, Serum Institute retained an exclusive license to use the Company’s PolyXen® technology to research and develop one potential commercial product, Polysialylated Erythropoietin (“PSA-EPO”). Serum Institute will be responsible for conducting all pre-clinical and clinical trials required to achieve regulatory approvals within the certain predetermined territories at Serum Institute’s own expense. The royalty payment schedule based on net revenues on the future commercial sales of PSA-EPO under the DMA was also modified as a result of the 2011 amendment.
Percentage of royalty payments of net sales			25.00%
Royalty revenue or expense			$ 0	$ 0
Common stock shares, subscribed \| shares				800,000
Common stock value, subscribed				$ 421,163
Synbio Llc [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development supply service revenues			$ 0	$ 100,000
Royalties receivable percentage			10.00%
Royalties payment percentage			10.00%
Share ownership percentage			45.30%	45.30%
Minimum [Member] \| Baxter Healthcare Sa And Baxter Healthcare Corporation [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Percentage of royalties			2.00%
Minimum [Member] \| Serum Institute Of India Limited [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Percentage of royalties			2.00%
Maximum [Member] \| Baxter Healthcare Sa And Baxter Healthcare Corporation [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Percentage of royalties			3.50%
Maximum [Member] \| Serum Institute Of India Limited [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Percentage of royalties			8.00%
Development And Manufacturing Arrangement [Member] \| Serum Institute Of India Limited [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestone or other research-related payments due under the DMA			$ 0