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Note 3 - Discontinued Operations (Details Textual) - USD ($) $ in Thousands		12 Months Ended
	Dec. 26, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Escrow Deposits Related to Property Sales		$ 4,465
Restructuring Charges		$ 881	$ 990
Atchison Facility [Member]
Disposal Group, Including Discontinued Operation, Consideration	$ 37,200
Restructuring Charges				600
Atchison Facility [Member] | Cost of Sales [Member]
Restructuring Charges				500
Atchison Facility [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Charges				$ 100
Atchison Facility [Member] | Until Receipt by Buyer [Member]
Escrow Deposits Related to Property Sales	750
Atchison Facility [Member] | To Secure Indemnification Obligations [Member]
Escrow Deposits Related to Property Sales	$ 3,700

X

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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X

- Definition

Escrow deposits related to property sales in noncash investing and financing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586

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-Section 50
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-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

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X

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747

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