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Principles of Consolidation (Details) - USD ($) $ in Thousands			1 Months Ended	3 Months Ended	6 Months Ended
	May 03, 2017	Apr. 13, 2016	Dec. 30, 2017	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Sale of GNU interest
Purchase price received						$ 250
GNU gain on sale of business assets				$ 250		$ 250
Disposal Group, Disposed of by Sale, Not Discontinued Operations | GNU
Sale of GNU interest
Purchase price		$ 1,350
Purchase price received	$ 250	$ 1,100
GNU gain on sale of business assets				140
GNU partial distribution gain received on sale of business assets			$ 600
GNU | Disposal Group, Disposed of by Sale, Not Discontinued Operations | GNU
Sale of GNU interest
GNU gain on sale of business assets				$ 250
GNU
GNU Interest
Percentage of ownership interest held by the entity					55.89%

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- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2443-110228

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84176398&loc=d3e2941-110230

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
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-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

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