Income Taxes Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Holiday [Line Items]
Income tax provision (benefit)	$ 364	$ 527	$ (358)	$ 3,117
Cumulative valuation allowance	61,400		61,400
Decrease in deferred tax liability			(789)	$ (981)
Deferred tax liability recorded associated with unremitted earnings of foreign subsidiary no longer considered indefinitely reinvested	4,900		4,900
Undistributed earnings of Swiss subsidiary	97,600		97,600
Repatriation of Swiss accumulated earnings	$ 10,000		$ 10,000
Withholding tax percentage	5.00%		5.00%
Swiss Federal Tax Administration (FTA) [Member]
Income Tax Holiday [Line Items]
Decrease in deferred tax liability			$ 400