Debt - Healthcare Royalty Financing Agreement Narrative (Details) - USD ($)			1 Months Ended		12 Months Ended
	May. 16, 2014	Jul. 18, 2011	Jul. 31, 2012	Jul. 31, 2011	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Warrant exercisable to Healthcare Royalty, shares				28,125
Warrant exercisable to Healthcare Royalty, (usd per share)				$ 72.00
Term of common stock warrant exercisable			5 years	10 years
Loss on extinguishment of debt	$ 1,254,000				$ 0	$ (1,254,000)	$ 0
Embedded Derivative Liabilities [Member]
Debt Instrument [Line Items]
Fair value of embedded derivatives	247,000
Healthcare Royalty Financing Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, outstanding		$ 30,000,000
Warrant exercisable to Healthcare Royalty, shares		28,125
Warrant exercisable to Healthcare Royalty, (usd per share)		$ 72.00
Term of common stock warrant exercisable		10 years
Repayments of Debt	$ 40,041,000
Healthcare Royalty Financing Agreement [Member] | Common Stock Warrant Liabilities [Member]
Debt Instrument [Line Items]
Change in fair value					$ 13,000	$ 378,000