Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of Minimum Lease Payments Under Non-cancelable Operating Leases

The minimum lease payments under the non-cancelable operating leases are payable in the following amounts over the following years.

	2018		2019		2020		2021		Total
Operating lease obligations	$	883	$	403	$	375	$	312	$	1,973
	$883		$403		$375		$312		$1,973