Income Taxes Other information (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax (Textual) [Abstract]
Income taxes paid		$ 300	$ 200	$ 100
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	$ 4,600
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	18,000	18,000
Undistributed Earnings of Foreign Subsidiaries	(8,400)	(8,400)
Goodwill	19,614	19,614	5,520	319
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year		3,249	3,136
Additions for tax positions of current year		865	544
Additions for tax positions of prior years		141	116
Reductions for tax positions of prior years		0	(547)
Balance at end of year	4,255	4,255	$ 3,249	$ 3,136
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	23,400	23,400
US Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 28,800	$ 28,800