Acquired Business and Noncontrolling Interests - Additional Information (Detail) - USD ($)	9 Months Ended
Sep. 29, 2018	Dec. 30, 2017	Sep. 30, 2017
Goodwill	$ 38,560,000	$ 39,065,000	$ 39,914,000
Fletes Avella \| Landstar Metro
Business combination, recognized identifiable assets acquired and liabilities assumed, liabilities		$ 1,900,000
Approximate ownership interest acquired by affiliates	21.00%
Goodwill	$ 7,900,000
Percentage of goodwill estimated to be deductible after purchase of noncontrolling interests by the company	100.00%
Fletes Avella \| Landstar Servicios
Approximate ownership interest acquired by affiliates	21.00%

Percentage of goodwill estimated to be deductible after purchase of noncontrolling interests by the company.

No definition available.

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- Definition

Amount of liabilities assumed at the acquisition date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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