Stockholders' Equity (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended				94 Months Ended		0 Months Ended	9 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended		1 Months Ended	3 Months Ended					0 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Sep. 30, 2013	Jan. 17, 2013	Apr. 16, 2013 April 2013 Registered Direct Offering	Sep. 30, 2013 June 21, 2012 Equity sales agreement	Nov. 14, 2011 November 14, 2011 securities purchase agreements	Jun. 30, 2013 November 14, 2011 securities purchase agreements	Dec. 01, 2011 November 14, 2011 securities purchase agreements Selling agent	Oct. 18, 2012 CRO stock purchase agreement	Jan. 31, 2013 CRO stock purchase agreement	Dec. 31, 2012 CRO stock purchase agreement	Sep. 30, 2013 CRO stock purchase agreement	Mar. 31, 2013 CRO stock purchase agreement	Dec. 31, 2012 CRO stock purchase agreement	Oct. 17, 2012 CRO stock purchase agreement	Jan. 17, 2013 Callisto Merger Agreement
Stockholders' Equity
Number of authorized shares of common stock		100,000,000	200,000,000		100,000,000				200,000,000	200,000
Stockholder's Equity
Common stock issued (in shares)											16,375,000	758,093
Common stock price (in dollars per share)											$ 5.50	$ 6.16				$ 4.55
Gross proceeds from sale of common stock by the entity			$ 94,734,000	$ 51,750,000					$ 211,168,000		$ 90,000,000	$ 4,700,000
Stock issuance costs			5,623,000						12,346,000		5,500,000	100,000
Number of units sold													1,328,941
Number of units issued for services (in units)															77,750
Number of shares of common stock per unit													1
Number of warrants per unit													1
Number of common shares that can be acquired upon exercise of each warrant													1
Fair value of derivative liabilities reclassified to equity	3,575,000	169,000												3,600,000
Fair value of common stock issued for services rendered			250,000		93,000	341,000	18,000	2,000											250,000
Fair value of common stock issued for services rendered (in shares)																				55,000
Closing stock price (in dollars per share)																						$ 4.57
Percentage of services completed of total contract																		50.00%
Stock based compensation expense			3,258,000	1,345,000					8,742,000								125,000				125,000
Shares issued in connection with merger																							28,605,379
Exchange Ratio of shares																							0.1799
Cancellation of stock (in shares)																							22,294,976
Lock-up period																							24 months
Shares granted in connection with merger																							1,221,316
Assets
Security deposits																							74,000
Total assets acquired																							74,000
Liabilities
Accounts payable and other liabilities																							(1,400,000)
Net assumed liabilities																							(1,326,000)
Elimination of amounts due from Callisto																							(3,578,000)
Recapitalization of Synergy			$ (4,904,000)						$ (4,904,000)														$ (4,904,000)