Debt (Details) € in Thousands, $ in Thousands	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 EUR (€)
Line of Credit Facility [Line Items]
Long-term Debt, Gross	$ 6,012	$ 3,274
Loan Fees and Original Issue Discount	(1,470)
Less current portion of long-term debt	(83)	(3,214)
Long-term debt	4,459	60
Hannoversech Volksbank Credit line 1 [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	0	1,321
Hannoversech Volksbank Credit line 2 [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	0	397
Hannoversech Volksbank term loan 3 [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	0	117
Secured Promissory Note [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	83	650
DZ Equity Partners Participation rights [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	0	$ 789
GPB convertible note payable [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	5,356		€ 0
Subordinated convertible notes payable [Member]
Line of Credit Facility [Line Items]
Long-term Debt, Gross	$ 573		€ 0