Stockholders' Equity - Summary of Warrant Activity (Details)	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Common Shares Issuable upon Exercise
Outstanding, beginning balance (in shares) | shares	2,317,846
Issued (in shares) | shares	5,199,138
Cancelled (in shares) | shares	(246,914)
Outstanding, ending balance (in shares) | shares	7,270,070
Exercisable at balance sheet date (in shares) | shares	7,270,070
Weighted Average Exercise Price
Outstanding, beginning balance (in usd per share) | $ / shares	$ 15.19
Issued (in usd per share) | $ / shares	1.60
Cancelled (in usd per share) | $ / shares	52.50
Outstanding, ending balance (in usd per share) | $ / shares	3.85
Exercisable at balance sheet date (in dollars per share) | $ / shares	$ 3.85