Major Customers, Partnerships and Strategic Alliances (Details Textual) (USD $)	3 Months Ended			1 Months Ended	3 Months Ended		1 Months Ended	3 Months Ended			1 Months Ended		3 Months Ended			1 Months Ended		3 Months Ended		1 Months Ended		3 Months Ended		1 Months Ended	3 Months Ended							1 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Oct. 31, 2009 California Institute for Regenerative Medicine [Member]	Mar. 31, 2013 California Institute for Regenerative Medicine [Member]	Mar. 31, 2012 California Institute for Regenerative Medicine [Member]	Apr. 30, 2011 CHDI Foundation, Inc. [Member]	Mar. 31, 2013 CHDI Foundation, Inc. [Member]	Mar. 31, 2012 CHDI Foundation, Inc. [Member]	Dec. 31, 2012 CHDI Foundation, Inc. [Member]	Mar. 31, 2012 Juvenile Diabetes Research Foundation International [Member]	Oct. 31, 2006 Juvenile Diabetes Research Foundation International [Member]	Mar. 31, 2013 Juvenile Diabetes Research Foundation International [Member]	Mar. 31, 2012 Juvenile Diabetes Research Foundation International [Member]	Mar. 31, 2010 Juvenile Diabetes Research Foundation International [Member]	Jun. 30, 2012 Shire AG [Member] Targets	Jan. 31, 2012 Shire AG [Member] Targets	Mar. 31, 2013 Shire AG [Member]	Mar. 31, 2012 Shire AG [Member]	Oct. 31, 2009 Sigma-Aldrich Corporation [Member]	Jul. 31, 2007 Sigma-Aldrich Corporation [Member]	Mar. 31, 2013 Sigma-Aldrich Corporation [Member]	Mar. 31, 2012 Sigma-Aldrich Corporation [Member]	Oct. 31, 2005 Dow AgroSciences [Member]	Mar. 31, 2013 Dow AgroSciences [Member]	Mar. 31, 2012 Dow AgroSciences [Member]	Mar. 31, 2013 License agreement terms [Member] California Institute for Regenerative Medicine [Member]	Mar. 31, 2012 License agreement terms [Member] California Institute for Regenerative Medicine [Member]	Mar. 31, 2013 License agreement terms [Member] Sigma-Aldrich Corporation [Member]	Mar. 31, 2012 License agreement terms [Member] Sigma-Aldrich Corporation [Member]	Oct. 31, 2009 License agreement terms [Member] Sigma-Aldrich Corporation [Member]	Oct. 31, 2005 License agreement terms [Member] Dow AgroSciences [Member]	Oct. 31, 2009 Upfront license fee [Member] Sigma-Aldrich Corporation [Member]	Oct. 31, 2005 Maximum [Member] Dow AgroSciences [Member]	Oct. 31, 2005 Minimum [Member] Dow AgroSciences [Member]
Major Customers, Partnerships and Strategic Alliances (Textual) [Abstract]
Aggregate number of gene targets																	7
Number of initial gene targets																	4
Number of gene targets																5
Number of additional gene targets																2
Research program to develop laboratory research reagents																		6 years			3 years			3 years
Upfront license fee																	$ 13,000,000			$ 20,000,000													$ 15,100,000
Expected amount to be received for research and development				5,200,000
Potential amount to be funded for certain Shire milestones																		213,500,000
IND or CTA submission amount																		8,500,000
Royalty revenues																		0				314,000	301,000	2,300,000								4,000,000
Deferred revenue	2,286,000		2,304,000															10,600,000
Collaboration Agreement Related Costs and Expenses					400,000	300,000		0	400,000										500,000
Public offering, common stock shares issued																				636,133
Common stock, valued																				4,900,000
Royalty revenues expected to be received																															5,000,000
Reduced royalty rate																				10.50%
Funding available under the amended agreement																				25,000,000
Related costs and expenses																		3,100,000							0	200,000			100,000	100,000
One time license fee earned on exercise of option																								6,000,000
Percentage of royalties to be received from sublicensing																								25.00%
Annual fees																																		3,000,000	250,000
Fee due																								25,300,000
Minimum sublicense annual fees specific reckoning period																								11 years
Revenue attributable to research and development																									0	400,000
Agreement date				2009-10			2011-04					2006-10
Funds due under the agreement				14,500,000
Agreement to receive				4 years			1 year
Receivables from sale against the grant funded to entity from sale of product					2
Revenues under the agreement								0	400,000				0	800,000													400,000	300,000
Funds due under agreement							1,300,000
Research grants	540,000	1,579,000
Funds due under agreement as per amendment										2,100,000
Contractual agreement termination date								Aug. 31, 2012
Grant funding amount maximum under amended agreement															3,000,000
Received for work performed under agreement											$ 800,000