Consolidated Statements of Cash Flows (Parentheticals) - USD ($)		12 Months Ended
Dec. 24, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Issuance costs	$ 200,000	$ 200,000

The cash outflow for cost incurred directly with the issuance of an equity security.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration