Information Regarding Reportable Business Segments (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Segment Reporting Information [Line Items]
External revenue	$ 1,202,081	$ 943,430	$ 3,432,793	$ 2,594,772
Internal revenue	7,496	7,335	30,413	29,773
Investment income	1,002	711	2,754	1,733
Operating income	87,068	60,567	245,647	173,919
Expenditures on long-lived assets	3,204	2,172	7,325	8,800
Goodwill	38,560	39,914	38,560	39,914	$ 39,065
Transportation Logistics
Segment Reporting Information [Line Items]
External revenue	1,188,737	931,692	3,394,298	2,559,847
Operating income	80,878	54,181	227,176	148,693
Expenditures on long-lived assets	3,204	2,172	7,325	8,800
Goodwill	38,560	39,914	38,560	39,914
Insurance
Segment Reporting Information [Line Items]
External revenue	13,344	11,738	38,495	34,925
Internal revenue	7,496	7,335	30,413	29,773
Investment income	1,002	711	2,754	1,733
Operating income	$ 6,190	$ 6,386	$ 18,471	$ 25,226

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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