Stockholders' Equity AOCI Disclosure (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Stockholders' Equity Attributable to Parent		$ 105,665	$ 106,502		$ 118,176		$ 116,540
Amortization of Intangible Assets		4,312	4,956		5,526
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		5,492	(9,209)		(4,153)
Interest Rate Swap
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Stockholders' Equity Attributable to Parent		(69)	(158)		(238)		(295)
OCI, before Reclassifications, Net of Tax, Attributable to Parent		12	(20)		(58)
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent	[1]	77	100		115
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		89	80		57
Accumulated Other Comprehensive (Loss) Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Stockholders' Equity Attributable to Parent		(11,317)	(16,809)		(7,600)		(3,447)
OCI, before Reclassifications, Net of Tax, Attributable to Parent		5,415	(9,309)		(4,268)
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent		77	100	[1]	115	[1]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		5,492	(9,209)		(4,153)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Stockholders' Equity Attributable to Parent		(11,247)	(16,651)		(7,363)		(3,156)
OCI, before Reclassifications, Net of Tax, Attributable to Parent		5,404	(9,288)		(4,207)
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent	[1]	0	0		0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		5,404	(9,288)		(4,207)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Stockholders' Equity Attributable to Parent		(1)	0		1		$ 4
OCI, before Reclassifications, Net of Tax, Attributable to Parent		(1)	(1)		(3)
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent	[1]	0	0		0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		$ (1)	$ (1)		$ (3)

[1] For additional information, see Note 2, "Marketable Securities", and see Note 15, "Derivative Instruments and Hedging Activities"