Pension and Other Postretirement Benefit Plans (Net periodic pension cost (income) and other amounts recognized in other comprehensive income (loss) before taxes) (Details) - USD ($) $ in Thousands	8 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Swiss Pension Plan
Components of net periodic pension cost:
Service cost			$ 982	$ 1,171	$ 958
Interest cost			230	246	332
Expected return on plan assets			(1,009)	(1,175)	(1,551)
Prior service cost amortization			151	150	136
Deferred loss amortization			0	243	45
Settlement cost			0	0	492
Net periodic pension cost			354	635	412
Other amounts recognized in other comprehensive income (loss) before income taxes are as follows:
Prior service cost amortization			(151)	(150)	(136)
(Gain) loss on value of plan assets			(2,118)	(476)	1,131
Actuarial loss before taxes			119	(2,425)	1,262
Plan change			0	0	83
Settlement			0	0	(492)
Deferred loss amortization			0	(243)	(45)
Total (income) loss recognized in other comprehensive income, before taxes			(2,150)	(3,294)	1,803
Total (income) recognized in net periodic pension cost and other comprehensive income, before taxes			(1,796)	$ (2,659)	$ 2,215
Korea Defined Benefit Plan
Components of net periodic pension cost:
Service cost	$ 361	$ 361
Interest cost	55	$ 55
Net periodic pension cost	416
Other amounts recognized in other comprehensive income (loss) before income taxes are as follows:
Actuarial loss before taxes	(174)		$ 174
Total (income) loss recognized in other comprehensive income, before taxes	174
Total (income) recognized in net periodic pension cost and other comprehensive income, before taxes	$ 590