Long-Term Borrowing (Details) - USD ($) $ in Thousands			12 Months Ended
	Dec. 23, 2016	Dec. 22, 2016	Dec. 31, 2016	Jun. 27, 2016
Debt Instrument [Line Items]
Repayments of Long-term Debt			$ 25,000
Amortization and accelerated recognition of debt issuance costs			1,760
NY Green Bank
Debt Instrument [Line Items]
Loan Amount	$ 25,000
Long-term borrowings	25,000		25,000
Debt issuance costs	$ 1,200
Interest rate spread (as a percent)	6.00%
Effective interest rate (as a percent)	11.30%
Term of loan agreement	3 years
2017			3,000
2018			8,400
2019			13,600
End of term charge			$ 1,000
Percent of securities in foreign subsidiaries guaranteed to secure debt			65.00%
Hercules Capital, Inc.
Debt Instrument [Line Items]
Loan Amount				$ 40,000
Long-term borrowings				25,000
Debt issuance costs				$ 1,400
Repayments of Long-term Debt		$ 25,000
End of term charge		4,000
Amortization and accelerated recognition of debt issuance costs		$ 1,100