Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		12 Months Ended
	Feb. 06, 2017	Jan. 31, 2017	May 06, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Net proceeds from private placement				$ 121,951	$ 0
Proceeds from exercise of warrants						$ 11,300
Warrants
Debt Instrument [Line Items]
Exercise of warrants (in shares)						2,430,657
Private Placement
Debt Instrument [Line Items]
Shares sold in private placement (in shares)			29,948,334
Shares issued (in dollars per share)			$ 3.00
Net proceeds from private placement			$ 89,800
Public Stock Offering
Debt Instrument [Line Items]
Shares sold in private placement (in shares)		20,325,204
Shares issued (in dollars per share)		$ 6.15
Net proceeds from private placement	$ 121,600