Acquisitions and Stockholders’ Equity (Deficit) (Details)								1 Months Ended	3 Months Ended				12 Months Ended
	May 06, 2016 USD ($) $ / shares shares	Mar. 18, 2016 USD ($) $ / shares shares	Mar. 05, 2014 USD ($) $ / shares	Feb. 18, 2014 USD ($) shares	Feb. 06, 2014 $ / shares	Feb. 04, 2014 USD ($) $ / shares shares	Jan. 28, 2014 shares	Nov. 30, 2016 USD ($) shares	Dec. 31, 2016 USD ($) $ / shares shares	Mar. 31, 2016 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Jul. 02, 2015 USD ($)	Jun. 08, 2015 shares	Nov. 03, 2014 USD ($) $ / shares	Feb. 05, 2014 $ / shares	Dec. 31, 2013 shares
Debt Instrument [Line Items]
Class of warrant or right exercise price of warrants or rights decrease (in dollars per share) | $ / shares					$ 0.011
Common stock, par value (in dollars per share) | $ / shares									$ 0.0001				$ 0.0001	$ 0.0001
Net proceeds from private placement													$ 89,845,000	$ 14,672,000	$ 30,700,000
Common stock, shares authorized (in shares) | shares									350,000,000				350,000,000	350,000,000			350,000,000			200,000,000
Common stock issued in connection with exercise of stock options													$ 222,000	$ 1,142,000	36,000
Debt conversion amount													137,941,000	40,989,000	0
Common stock issued for interest on Notes													2,445,000	0	0
Proceeds of sale of common stock — ContraVir													0	0	3,224,000
Derivative financial instruments, at estimated fair value-warrants									$ 216,000				$ 216,000	$ 322,000
Noncontrolling interest, decrease from redemptions or purchase of interests															$ 1,622,000
Contra Vir Pharmaceuticals Inc | Spinoff
Net Assets Eliminated in Connection with Spin-off [Abstract]
Cash				$ 3,230,000
Prepaid expense				6,000
Total assets				3,236,000
Accounts payable and other liabilities				(107,000)
Note Payable to Synergy				(455,000)
Due to Synergy				(54,000)
Derivative financial instruments, at estimated fair value-warrants				(880,000)
Total Liabilities				(1,496,000)
Spinoff Net Asset				$ 1,740,000
Common Shares
Debt Instrument [Line Items]
Shares sold in private placement (in shares) | shares													29,948,334
Common stock issued in connection with exercise of warrants (in shares) | shares													2,430,656	189,412
Common stock issued in connection with exercise of stock options (in shares) | shares													70,185	269,720	9,999
Debt conversion expense (in shares) | shares		9,600,000											12,161,671
Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Aggregate principal amount (not exceeding)									23,500,000				$ 23,500,000	$ 159,000,000	$ 200,000,000			$ 200,000,000
Debt conversion amount		$ 79,800,000						$ 55,700,000	$ 55,668,000	$ 79,829,000	$ 18,776,000	$ 22,213,000
Percent of principal converted		50.00%						70.00%
Number of shares issued on conversion of debt (in shares) | shares		35,300,000						20,500,000					56,600,000
Number of shares issued on conversion price excluding share issued for accrued interest (in shares) | shares		25,600,000						17,900,000
Conversion price (in dollars per share) | $ / shares		$ 3.11																$ 3.11
Number of shares issued for accrued interest (in shares) | shares		872,000
Five day average conversion price for accrued interest (in dollars per share) | $ / shares		$ 2.81
Common stock issued for interest on Notes		$ 2,400,000
Debt conversion expense (in shares) | shares									2,600,000
Debt conversion, recognized expense								$ 14,500,000		$ 25,600,000
Percent of outstanding aggregate principal amount converted								70.00%
Shares issued, representing conversion price pursuant to existing terms (in shares) | shares								17,900,000
Additional interest expense from acceleration of deferred debt costs								$ 2,000,000					$ 6,700,000	12,900,000
Debt conversion, recognized expense (in shares) | shares								2,600,000
Debt conversion													135,500,000
June 2012 Equity Sales Agreement
Debt Instrument [Line Items]
Net proceeds from private placement													$ 11,300,000	$ 1,000,000
Common stock issued in connection with exercise of warrants (in shares) | shares													2,430,657	189,412
Common stock issued in connection with exercise of stock options (in shares) | shares														269,720
Common stock issued in connection with exercise of stock options														$ 1,100,000
Shelf Registration
Debt Instrument [Line Items]
Aggregate principal amount (not exceeding)																$ 250,000,000
Private Placement
Debt Instrument [Line Items]
Shares sold in private placement (in shares) | shares	29,948,334
Net proceeds from private placement	$ 89,800,000
Shares issued (in dollars per share) | $ / shares	$ 3.00
February 2014 Securities Purchase Agreement | Contra Vir Pharmaceuticals Inc
Debt Instrument [Line Items]
Proceeds of sale of common stock — ContraVir						$ 3,200,000
Private placement expenses						$ 15,000
Number of units sold (in shares) | shares						9,485,294
Number of common shares for each unit (in shares) | shares						1
Number of warrants for each unit (in shares) | shares						1
Number of common shares that can be acquired upon exercise of each warrant (in shares) | shares						0.5
Purchase price per unit (in dollars per share) | $ / shares						$ 0.34
February 2014 Securities Purchase Agreement | Warrants | Contra Vir Pharmaceuticals Inc
Debt Instrument [Line Items]
Balance of warrants outstanding (in shares) | shares						4,700,000
Exercise price of warrants or rights (in dollars per share) | $ / shares						$ 0.37
Class of warrant or right expiration period						6 years
Derivative financial instruments, at estimated fair value-warrants						$ 880,000
Cantor Fitzgerald & Co.
Debt Instrument [Line Items]
Common stock, par value (in dollars per share) | $ / shares			$ 0.0001
Cantor Fitzgerald & Co. | June 2012 Equity Sales Agreement
Debt Instrument [Line Items]
Aggregate additional maximum issue amount			$ 50,000,000
Issuance costs (up to)			0.03
Shares sold in private placement (in shares) | shares													3,435,998		6,417,650
Net proceeds from private placement													$ 14,700,000		$ 30,700,000
Share price, average (in dollars per share) | $ / shares													$ 4.27		$ 4.78
Attorney fees													$ 400,000		$ 800,000
Public Company
Debt Instrument [Line Items]
Balance of warrants outstanding (in shares) | shares									919,690				919,690
Public Company | Weighted Average
Debt Instrument [Line Items]
Exercise price of warrants or rights (in dollars per share) | $ / shares									$ 5.22				$ 5.22						$ 5.24
Contra Vir Pharmaceuticals Inc
Debt Instrument [Line Items]
Related party potential distribution of common stock (in shares) | shares							9,000,000
Dividend declared, number of shares of subsidiary to be distributed for each share of common stock held by stockholders of entity (in shares) | shares							0.0986
Dividend distributed number of shares of subsidiary distributed for each share of common stock held by stockholders of entity (in shares) | shares				0.0986
Contra Vir Pharmaceuticals Inc | Spinoff
Debt Instrument [Line Items]
Noncontrolling interest, decrease from redemptions or purchase of interests				$ 1,600,000