Cash, Cash Equivalents and Available for Sale Securities - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Changes in accumulated other comprehensive income (loss)
Beginning balance			$ (94,618)
Current period changes in fair value before reclassifications, net of tax	$ 36	$ (122)	26	$ 355
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0	0	0	0
Other comprehensive income (loss)	36	(122)	26	355
Ending balance	(148,820)		(148,820)
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss)
Beginning balance	(222)	4	(212)	(473)
Ending balance	$ (186)	$ (118)	$ (186)	$ (118)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

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

+ References

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-Publisher FASB
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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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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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