Defined Benefit Plans (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Swiss Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 134	$ 155	$ 400	$ 500
Additional employer contributions expected to be paid during the remainder of fiscal year	113		113
Korea Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	1	$ 2	6	$ 4
Additional employer contributions expected to be paid during the remainder of fiscal year	$ 1		$ 1
Minimum years of service			1 year