Acquisition and Stockholders' Equity (Deficit) (Details 3) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended					98 Months Ended			0 Months Ended				0 Months Ended	1 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended	12 Months Ended	0 Months Ended	2 Months Ended		0 Months Ended
	Jan. 29, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2013	Jan. 15, 2013	Nov. 20, 2009	Feb. 06, 2014 Subsequent Event	Jan. 28, 2014 ContraVir Subsidiary Subsequent Event	Dec. 31, 2013 Weighted average	Feb. 06, 2014 Weighted average Subsequent Event	Oct. 18, 2012 CRO stock purchase agreement	Jan. 31, 2013 CRO stock purchase agreement	Dec. 31, 2012 CRO stock purchase agreement	Mar. 31, 2013 CRO stock purchase agreement	Oct. 17, 2012 CRO stock purchase agreement	Apr. 16, 2013 April 2013 Registered Direct Offering	Dec. 31, 2012 June 21, 2012 Equity sales agreement	Dec. 31, 2013 June 21, 2012 Equity sales agreement	Mar. 14, 2014 June 21, 2012 Equity sales agreement Subsequent Event	Feb. 27, 2014 June 21, 2012 Equity sales agreement Subsequent Event	Dec. 31, 2013 June 21, 2012 Equity sales agreement Weighted average	Jan. 17, 2013 Callisto Merger Agreement
Fair value of common stock issued for services rendered		$ 92,663	$ 250,000	$ 93,000	$ 341,295	$ 18,000	$ 2,000								$ 250,000
Common stock issued for services rendered (in shares)	26,272				79,000													55,000
Closing stock price (in dollars per share)																			$ 4.57						$ 6.16
Percentage of services completed of total contract																	50.00%
Stock based compensation expense			4,614,000	2,515,000	822,000			10,098,000								125,000	125,000
Number of authorized shares of common stock			200,000,000	100,000,000				200,000,000	200,000,000	100,000,000
Shares approved for distribution												9,000,000
Shares of subsidiary to be distributed for each share of entity's shares outstanding												0.0986
Decrease in exercise price (in dollars per share)											$ 0.011
Warrants outstanding			5,647,203					5,647,203
Exercise price of warrants (in dollars per share)													$ 5.37	$ 5.359
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)
Common stock issued (in shares)																				16,375,000	815,654	758,093	107,808	3,644,143
Common stock price (in dollars per share)															$ 4.55					$ 5.50	$ 5.04		$ 6.09	$ 5.82
Gross proceeds from sale of common stock by the entity			94,734,000	55,862,000	34,369,000			211,168,000												90,000,000	4,111,802	4,700,000	656,238	21,216,860
Stock issuance costs			$ 5,623,000	$ 3,774,000	$ 2,148,000			$ 12,346,000												$ 5,500,000		$ 100,000