Contractual Agreements (Details)	3 Months Ended		9 Months Ended			12 Months Ended							1 Months Ended			9 Months Ended			1 Months Ended		1 Months Ended								1 Months Ended
	Sep. 30, 2012 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2011 USD ($)	Nov. 28, 2012 Tekmira [Member] USD ($)	Dec. 31, 2009 Novartis [Member] USD ($)	Aug. 02, 2012 Novartis [Member] USD ($)	Mar. 31, 2009 Novartis [Member] USD ($)	May 03, 2012 Monsanto [Member] USD ($)	Mar. 13, 2012 ProNAi Therapeutics, Inc. [Member] USD ($)	Dec. 22, 2011 Mirna Therapeutics [Member] USD ($)	Feb. 28, 2011 Debiopharm S.A. [Member] USD ($)	Mar. 31, 2010 Valeant Pharmaceuticals [Member] USD ($)	Dec. 31, 2011 Novosom [Member] USD ($)	Jul. 31, 2010 Novosom [Member] USD ($)	Sep. 30, 2012 Novosom [Member]	Oct. 21, 2012 Roche [Member] USD ($)	Feb. 28, 2009 Roche [Member] USD ($)	May 31, 2008 University of Michigan [Member] USD ($)	Jun. 30, 2008 University of Helsinki [Member] EUR (€)	May 31, 2011 Ribotask ApS [Member] USD ($)	Mar. 31, 2011 Ribotask ApS [Member] USD ($)	Nov. 30, 2010 Ribotask ApS [Member] USD ($)	Jun. 30, 2010 Ribotask ApS [Member] USD ($)	Jun. 30, 2009 Ribotask ApS [Member] USD ($)	Feb. 28, 2009 Ribotask ApS [Member] USD ($)	Oct. 31, 2008 Ribotask ApS [Member] USD ($)	Aug. 31, 2010 Cypress Bioscience, Inc. [Member] USD ($)	Jan. 31, 2009 Amylin Pharmaceuticals, Inc. [Member] USD ($)	Dec. 31, 2006 Amylin Pharmaceuticals, Inc. [Member] USD ($)
Contractual Agreements [Line Items]
One-time, initial license fee					$ 300,000		$ 1,000,000	$ 7,250,000	$ 1,500,000								$ 1,000,000	$ 5,000,000										$ 750,000
Days notice required to terminate agreement					90					90	60		30																60
License revenue						300,000
Potential upfront revenue										14,000,000	63,000,000	24,000,000
Potential total revenue from agreement																												27,000,000	89,000,000	80,000,000
Possible milestone payment													5,000,000							275,000
Possible second milestone payment													2,000,000
Minimum earn-out payments needed													5,000,000
Conditional annual payments													50,000
Shares issued for intellectual property															1,419,490	340,906						11,377			15,152
Value of shares issued for intellectual property															3,800,000							80,000			1,000,000
Additional consideration for assets, percentage															30.00%
Maximum additional consideration for assets															3,300,000
Research and development expense	753,000	2,955,000	4,506,000	9,077,000									500,000	100,000
License issue fee																			120,000
Annual license fee payable																			25,000
Royalty advance																				250,000
Payments related to intellectual property																						400,000		750,000	1,000,000	250,000	500,000
Accelerated milestone revenue																													1,000,000
Installment payments amount																					$ 50,000		$ 250,000	$ 250,000	$ 250,000
Number of installment payments																						8		3	4