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[Line Items] for Significant Accounting Policies [Table]

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Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

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Amount 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation.

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No definition available.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value.

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Amount of interest capitalized during the period.

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Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

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Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

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Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

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The charge against earnings resulting from the aggregate write down of tangible assets from their carrying value to their fair value.

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Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 28, 2019 USD ($)	Dec. 28, 2019 USD ($) reporting_unit	Dec. 28, 2019 USD ($) segment	Dec. 28, 2019 USD ($)	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)
Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 60,694,000	$ 60,694,000	$ 60,694,000	$ 60,694,000	$ 43,579,000
Cash deposits in excess of FDIC insured limit	60,400,000	60,400,000	60,400,000	60,400,000	43,400,000
Inventory write-downs				0	0
Capitalized interest				0	0	$ 0
Impairment of intangibles				0	0	0
Impairment of long-lived assets				0	0
Research and development expense				200,000	400,000	500,000
Advertising expense				400,000	400,000	500,000
Self insurance stop loss limit				300,000
Self insurance reserve	2,000,000.0	$ 2,000,000.0	$ 2,000,000.0	2,000,000.0	1,200,000
Expenses incurred for healthcare benefits				17,600,000	13,300,000	11,900,000
Number of reporting units		2	2
Goodwill	$ 32,997,000	$ 32,997,000	$ 32,997,000	32,997,000	34,123,000	31,580,000
Software
Significant Accounting Policies [Line Items]
Software, estimated useful life	9 years
Software \| Minimum
Significant Accounting Policies [Line Items]
Software, estimated useful life	5 years
Software \| Maximum
Significant Accounting Policies [Line Items]
Software, estimated useful life	10 years
Buildings and Storage Tanks \| Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	10 years
Buildings and Storage Tanks \| Maximum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	39 years
Machinery, Vehicles and Equipment \| Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Machinery, Vehicles and Equipment \| Maximum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	25 years
Leasehold Improvements \| Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	5 years
Equipment at Customers \| Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	7 years
Equipment at Customers \| Maximum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	15 years
Oil Business
Significant Accounting Policies [Line Items]
Goodwill	$ 0	0	0	0	0	$ 0
Outside the United States of America
Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 100,000	$ 100,000	$ 100,000	$ 100,000	$ 200,000