Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 30, 2016	Sep. 30, 2016	Jan. 01, 2016
Property, plant and equipment, accumulated depreciation	$ 125,286	$ 123,921	$ 119,171
Class A [Member]
Common stock, shares issued	8,773,175	8,778,028	8,805,489
Common stock, shares outstanding	8,773,175	8,778,028	8,805,489
Treasury stock, shares	79,071	64,323	37,015
Class B [Member]
Common stock, shares issued	1,212,006	1,212,006	1,212,382
Common stock, shares outstanding	1,212,006	1,212,006	1,212,382

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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