| Intangible assets, net | 9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sep. 30, 2017 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intangible assets, net | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intangible assets, net | 
 Note 7 — Intangible assets, net 
 Intangible assets, net consisted of the following (in thousands): 
 
 
 Amortization expense was $108,000 and $40,000 for the three months ended September 30, 2017 and 2016, respectively, and $267,000 and $122,000 for the nine months ended September 30, 2017 and 2016, respectively. 
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