Patents Cost and Accumulated Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Patents [Line Items]
Patent cost, disposals	$ 0	$ 500	$ 3,000
Accumulated amortization, disposals	0	120	298
Proceeds from Sale of Intangible Assets	$ 0	$ 750	$ 3,500

The cash inflow from disposal of asset without physical form usually arising from contractual or other legal rights, excluding goodwill.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3179-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration