Subsequent Events - Additional Information (Details) $ / shares in Units, $ in Millions			9 Months Ended
	Sep. 05, 2017 USD ($) $ / shares shares	Aug. 29, 2017 USD ($) MW	Jul. 31, 2017
Subsequent Event [Line Items]
Stockholders' equity, reverse stock split			1-for-12
Hercules Capital, Inc. [Member]
Subsequent Event [Line Items]
Debt Instrument, Covenant Description			The loan contains a financial covenant whereby the Company is required to maintain an unrestricted cash balance of at least (a) 75% of the outstanding Loan balance plus (b) the amount of accounts payable (as defined under GAAP) not paid within 90 days of the date payment was issued.
Series C Preferred Stock [Member] | Convertible Preferred Offering [Member] | Hercules Capital, Inc. [Member]
Subsequent Event [Line Items]
Debt Instrument, Covenant Description			to require us to maintain an unrestricted blocked cash balance of at least the greater of (x) (a) $20.0 million plus (b) the amount of accounts payable not paid within 90 days of the date payment was issued and (y) (a) 100% of the outstanding loan balance plus (b) the amount of accounts payable not paid within 90 days of the date payment was issued
Subsequent Event [Member] | Series C Preferred Stock [Member] | Convertible Preferred Offering [Member]
Subsequent Event [Line Items]
Underwritten offering of convertible preferred stock | shares	33,500
Preferred stock dividend rate	0.00%
Conversion of stock conversion price | $ / shares	$ 1.84
Stock price per share | $ / shares	$ 895.52
Gross proceeds from sale of preferred stock	$ 30.0
Offering closed date	Sep. 08, 2017
Subsequent Event [Member] | Series C Preferred Stock [Member] | Convertible Preferred Offering [Member] | Hercules Capital, Inc. [Member]
Subsequent Event [Line Items]
Minimum unrestricted blocked cash balance	$ 20.0
Subsequent Event [Member] | Hanyang Industrial Development Company Ltd. [Member]
Subsequent Event [Line Items]
Contract to sell fuel cell plants | MW		20
Project represent in excess of product revenue		$ 60.0