Business Combinations (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 26, 2020	Sep. 28, 2019	Dec. 31, 2019
Investment in businesses	$ 5,240	$ 5,527
Liabilities assumed	380	402	$ 1,479
Debt issued for purchases of businesses	1,034	1,322	2,612
Payments to Acquire Businesses, Gross	3,826		8,529
Cash	0		3
Receivables	0		2,332
Operating supplies	23		84
Prepaid expense	0		27
Equipment	623		1,837
Deposits and other	0		96
Intangibles	2,018		4,067
Goodwill	$ 2,576	$ 1,798	$ 4,174
Tradenames [Member]
Finite-Lived Intangible Asset, Useful Life	6 years
Customer lists [Member]
Finite-Lived Intangible Asset, Useful Life	6 years
Noncompete Agreements [Member]
Finite-Lived Intangible Asset, Useful Life	5 years

Fair value of acquired receivable from business combination, excluding certain loans and debt securities acquired in transfer.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment, acquired at the acquisition date.

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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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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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