Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Changes in accumulated other comprehensive income (loss) by component
Balance	$ 265,431
Balance	247,836
Unrealized Gain (Loss) on Marketable Securities, net of tax
Changes in accumulated other comprehensive income (loss) by component
Balance	(55)	$ (289)
Other comprehensive income before reclassifications	21	380
Net current-period other comprehensive income	21	380
Balance	(34)	91
Foreign Currency Items
Changes in accumulated other comprehensive income (loss) by component
Balance	2,596	2,596
Balance	2,596	2,596
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss) by component
Amounts reclassified from other comprehensive income	0	0
Balance	2,541	2,307
Other comprehensive income before reclassifications	21	380
Net current-period other comprehensive income	21	380
Balance	$ 2,562	$ 2,687

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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