Convertible Notes - Promissory Notes Outstanding (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt discount	$ (18,088)		$ 0
Convertible Debt
Debt Instrument [Line Items]
Convertible promissory notes	18,088		0
Debt discount		$ (18,100)
Convertible promissory notes, net	0		0
Issued with September 2016 Convertible Notes
Debt Instrument [Line Items]
Debt discount	(9,643)	(9,600)	0
Compounded Bifurcated Derivatives
Debt Instrument [Line Items]
Debt discount	(1,273)	(1,300)	0
Beneficial Conversion Feature
Debt Instrument [Line Items]
Debt discount	$ (7,172)	$ (7,200)	$ 0