Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

Future minimum lease payments under non-cancelable leases, by year and in the aggregate, as of December 31, 2016 (in thousands) are as follows:

Years Ending December 31,
2017	$	646
2018		760
2019		784
2020		687
2021		345
Thereafter		380
Total minimum lease payments	$	3,602