Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Fair Value Measurements (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 01, 2017	Jan. 01, 2017
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 12,461
Level 1 \| Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash equivalents	$ 4,173	$ 100,900
Common Stock Warrants - Issued May 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Exercise price (USD per share)		$ 4.00
Common Stock Warrants - Issued October 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Exercise price (USD per share)	$ 7.74	$ 7.74
Warrant \| Common Stock Warrants - Issued May 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Exercise price (USD per share)	$ 4.00