Inventory (Schedule of Inventory Allowance) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Inventory Valuation Reserves [Roll Forward]
Beginning balance	$ (19)	$ (15)	$ (15)
Accruals	(3,758)	(4)	(273)
Write-offs	3,753	0	273
Ending balance	$ (24)	$ (19)	$ (15)

Amount of valuation reserve for inventory.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant