Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Lease expense	$ 417	$ 157	$ 175
Future lease payments for operating leases with initial or remaining noncancelable term of one year or more [Abstract]
2018	297
2019	297
2020	80
2021 and thereafter	6
Total minimum payments required	$ 680