Consolidated Statements of Preferred Stock and Stockholders' Equity (Deficit) (USD $) In Thousands, except Share data	Total USD ($)	Series A Convertible Preferred Stock USD ($)	Common Stock USD ($)	Additional Paid-in Capital USD ($)	Deficit Accumulated During Development Stage USD ($)	Issuance for Notes Payable and Related Accrued Interest on January 3, 2005 USD ($)	Issuance for Notes Payable and Related Accrued Interest on January 3, 2005 Common Stock	Issuance for Notes Payable and Related Accrued Interest on January 3, 2005 Additional Paid-in Capital USD ($)	Issuance for Intellectual Property License Rights on October 14, 2005 USD ($)	Issuance for Intellectual Property License Rights on October 14, 2005 Common Stock	Issuance for Intellectual Property License Rights on October 14, 2005 Additional Paid-in Capital USD ($)	Issuance for Notes Payable and Related Accrued Interest on October 14, 2005 USD ($)	Issuance for Notes Payable and Related Accrued Interest on October 14, 2005 Common Stock	Issuance for Notes Payable and Related Accrued Interest on October 14, 2005 Additional Paid-in Capital USD ($)	Issuance for Intellectual Property License Rights on February 21, 2006 USD ($)	Issuance for Intellectual Property License Rights on February 21, 2006 Common Stock	Issuance for Intellectual Property License Rights on February 21, 2006 Additional Paid-in Capital USD ($)	Issuance for Intellectual Property License Rights on February 22, 2006 USD ($)	Issuance for Intellectual Property License Rights on February 22, 2006 Common Stock	Issuance for Intellectual Property License Rights on February 22, 2006 Additional Paid-in Capital USD ($)	Issuance for Intellectual Property License Rights on June 23, 2006 USD ($)	Issuance for Intellectual Property License Rights on June 23, 2006 Common Stock	Issuance for Intellectual Property License Rights on June 23, 2006 Additional Paid-in Capital USD ($)	Issuance for Intellectual Property License Rights on November 7, 2006 Common Stock	Accretion of Series A USD ($)	Accretion of Series A Additional Paid-in Capital USD ($)	Accretion of Series B USD ($)	Accretion of Series B Additional Paid-in Capital USD ($)	Issuance for Intellectual Property License Rights on January 18, 2007 USD ($)	Issuance for Intellectual Property License Rights on January 18, 2007 Common Stock	Issuance for Intellectual Property License Rights on January 18, 2007 Additional Paid-in Capital USD ($)	Issuance for Intellectual Property License Rights on June 30, 2007 USD ($)	Issuance for Intellectual Property License Rights on June 30, 2007 Common Stock	Issuance for Intellectual Property License Rights on June 30, 2007 Additional Paid-in Capital USD ($)	Issuance of Common Stock for Commercial License Rights, on July 19, 2007 Common Stock	Issuance of Shares to Executive Subject to Repurchase Common Stock	Common Conversion USD ($)	Common Conversion Common Stock USD ($)	Common Conversion Additional Paid-in Capital USD ($)	Notes and Related Accrued Interest Common Stock	Cash, Net of Offering Costs USD ($)	Cash, Net of Offering Costs Series A Convertible Preferred Stock USD ($)	Cash, Net of Offering Costs Common Stock USD ($)	Cash, Net of Offering Costs Additional Paid-in Capital USD ($)	Cash, Net of Offering Costs Deficit Accumulated During Development Stage USD ($)	Series A USD ($)	Series A Series A offering costs USD ($)	Series A Issuance of Series A on February 22, 2006 USD ($)	Series A Third Issuance For Notes Payable And Related Accrued Interest USD ($)	Series A Redeemable Convertible Preferred Stock USD ($)	Series A Accretion of Series A USD ($)	Series A Common Conversion USD ($)	Series A Cash, Net of Offering Costs USD ($)	Series B USD ($)	Series B Third Issuance Of Series B Convertible Redeemable Preferred Stock USD ($)	Series B Issuance for Series B on December 28, 2007 USD ($)	Series B Accretion of Series B USD ($)	Series B Common Conversion USD ($)	Series B Cash, Net of Offering Costs USD ($)
Beginning Balance, value at Dec. 17, 2001
Beginning Balance, shares at Dec. 17, 2001
Issuance of equity for cash or intellectual property rights, value	1			1
Issuance of equity for cash or intellectual property rights, shares			2,588
Net loss	(116)				(116)
Ending Balance, value at Dec. 31, 2003	(115)			1	(116)
Ending Balance, shares at Dec. 31, 2003			2,588
Issuance of equity for cash or intellectual property rights, value	7			7
Issuance of equity for cash or intellectual property rights, shares			19,720
Net loss	(511)				(511)
Ending Balance, value at Dec. 31, 2004	(619)			8	(627)
Ending Balance, shares at Dec. 31, 2004			22,308
Issuance of equity for cash or intellectual property rights, value	1			1		1		1	44		44	1,354		1,354
Issuance of equity for cash or intellectual property rights, shares			2,922				2,978			903			31,095
Net loss	(1,459)				(1,459)
Ending Balance, value at Dec. 31, 2005	(678)			1,408	(2,086)
Ending Balance, shares at Dec. 31, 2005			60,206
Issuance of equity for cash or intellectual property rights, value															75		75	60		60	15		15																									9,316		5,000
Issuance of equity for cash or intellectual property rights, shares																17,372			13,907			2,505		38																								5,727,354		3,074,086
Share-based compensation	39			39
Net loss	(5,241)				(5,241)
Offering Costs	(17)			(17)																																										17	(98)
Issuance of preferred stock upon conversion of note payable and accrued interest, value																																																	684
Issuance of preferred stock upon conversion of note payable and accrued interest, shares																																																	420,817
Issuance of common stock upon exercise of stock options, for cash, value	3			3
Issuance of common stock upon exercise of stock options, for cash, shares			8,019
Ending Balance, value at Dec. 31, 2006	(5,744)			1,583	(7,327)																																									14,919
Ending Balance, shares at Dec. 31, 2006			102,047																																											9,222,257
Issuance of equity for cash or intellectual property rights, value																													13		13	7		7																					9,000	9,000
Issuance of equity for cash or intellectual property rights, shares																														1,303			642		2,783	13,915																			3,688,902	2,766,677
Share-based compensation	50			50
Net loss	(13,994)				(13,994)
Offering Costs																									(19)	(19)	(18)	(18)																							19			(147)			18
Issuance of common stock upon exercise of stock options, for cash, value	16			16
Issuance of common stock upon exercise of stock options, for cash, shares			2,227
Ending Balance, value at Dec. 31, 2007	(19,689)			1,632	(21,321)																																									14,938								17,871
Ending Balance, shares at Dec. 31, 2007			122,917																																											9,222,257								6,455,579
Share-based compensation	545			545
Net loss	(19,431)				(19,431)
Offering Costs																									(20)	(20)	(36)	(36)																							20						36
Issuance of common stock upon exercise of stock options, for cash, value	54			54
Issuance of common stock upon exercise of stock options, for cash, shares			36,154
Estimated fair value of warrants issued in connection with convertible notes payable	399			399
Ending Balance, value at Dec. 31, 2008	(38,178)			2,574	(40,752)																																									14,958								17,907
Ending Balance, shares at Dec. 31, 2008			159,071																																											9,222,257								6,455,579
Adjustment for fractional shares			(102)																																			(7)
Deemed preferred stock dividend for additional common shares issuable under anti-dilution provision	(781)			(781)																																																		781
Conversion of convertible securities																																					33,781	1	33,780													(15,000)						(18,781)
Conversion of convertible notes, shares																																								145,465
Merger with Nuvelo, Inc., value	11,913			11,913
Merger with Nuvelo, Inc., shares			447,826
Issuance of common stock under employee stock purchase plan and upon vesting of restricted stock units, value	2			2
Issuance of common stock under employee stock purchase plan and upon vesting of restricted stock units, shares			177
Share-based compensation				845
Net loss	(9,138)				(9,138)
Offering Costs																									(42)	(42)	(93)	(93)																							42						93
Issuance of common stock upon exercise of stock options, for cash, value	114			114
Issuance of common stock upon exercise of stock options, for cash, shares			10,521
Conversion of preferred stock, shares			507,123																																											(9,222,257)								(6,455,579)
Restricted stock release from restriction	75			75
Conversion of convertible notes and related accrued interest	8,501			8,501
Conversion of warrants for preferred stock	36			36
Estimated fair value of warrants issued in connection with lease termination	377			377
Ending Balance, value at Dec. 31, 2009	7,412		1	57,301	(49,890)
Ending Balance, shares at Dec. 31, 2009			1,270,074
Issuance of equity for cash or intellectual property rights, value																																									7,182			7,182
Issuance of equity for cash or intellectual property rights, shares																																											194,100
Share-based compensation	458			458
Net loss	(8,420)				(8,420)
Issuance of common stock upon exercise of stock options, for cash, value	139			139
Issuance of common stock upon exercise of stock options, for cash, shares			8,248
Ending Balance, value at Dec. 31, 2010	6,771		1	65,080	(58,310)
Ending Balance, shares at Dec. 31, 2010			1,472,422
Issuance of equity for cash or intellectual property rights, value																																									4,017		1	4,016
Issuance of equity for cash or intellectual property rights, shares																																											557,890
Share-based compensation	308			308
Net loss	(5,364)				(5,364)
Issuance of common stock upon exercise of stock options, for cash, value
Issuance of common stock upon exercise of stock options, for cash, shares			188
Ending Balance, value at Dec. 31, 2011	5,732		2	69,404	(63,674)
Ending Balance, shares at Dec. 31, 2011			2,030,500
Issuance of equity for cash or intellectual property rights, value	1,189		1	1,188
Issuance of equity for cash or intellectual property rights, shares																																											629,815
Share-based compensation	306			306
Net loss	(4,320)				(4,320)
Issuance of common stock upon exercise of stock options, for cash, value
Ending Balance, value at Dec. 31, 2012	2,907		3	70,898	(67,994)
Ending Balance, shares at Dec. 31, 2012			2,660,315
Adjustment for fractional shares																																						(64)
Conversion of convertible securities																																					(20)	13	(33)
Issuance of equity for cash or intellectual property rights, value																																									1,421			1,421
Issuance of equity for cash or intellectual property rights, shares																																											521,066
Share-based compensation	283			283
Net loss	(6,939)				(6,939)
Conversion of preferred stock, shares		(125,000)	12,500,000
Issuance of common stock upon exercise of warrants for cash, value	12			12
Issuance of common stock upon exercise of warrants for cash, share			4,245
Issuance of Series A convertible preferred stock, net of offering costs, Shares	17,917	125,000		17,917
Issuance of Series A convertible preferred stock, net of offering costs, Value
Deemed preferred stock dividend for beneficial conversion feature	2,026			2,026
Impact of deemed preferred stock dividend for beneficial conversion feature on common stockholders	(2,026)			(2,026)
Ending Balance, value at Dec. 31, 2013	15,581		16	90,498	(74,933)
Ending Balance, shares at Dec. 31, 2013			15,685,562
Issuance of equity for cash or intellectual property rights, value																																									7,866		5	7,861
Issuance of equity for cash or intellectual property rights, shares																																											5,116,228
Share-based compensation	158			158
Net loss	(2,389)				(2,389)
Issuance of common stock upon exercise of stock options, for cash, value	318			318
Issuance of common stock upon exercise of stock options, for cash, shares			199,900
Ending Balance, value at Mar. 31, 2014	$ 21,534		$ 21	$ 98,835	$ (77,322)
Ending Balance, shares at Mar. 31, 2014			21,001,690