Information Regarding Reportable Business Segments (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 29, 2025	Mar. 30, 2024	Dec. 28, 2024
Segment Reporting Information [Line Items]
Revenue		$ 1,152,502	$ 1,171,043
Gross revenue		1,164,081	1,183,112
Investment income		3,598	3,412
Purchased transportation		897,878	905,521
Commissions to agents		93,314	97,282
Other operating costs, net of gains on asset sales/dispositions		11,829	14,859
Insurance and claims		51,431	38,337
Selling, general and administrative		61,582	56,422
Depreciation and amortization		12,226	14,142
Operating income		39,419	59,961
Interest and debt (income) expense	[1]	(159)	(1,611)
Income before income taxes		39,578	61,572
Goodwill		40,881	42,381	$ 40,933
Related Party [Member]
Segment Reporting Information [Line Items]
Revenue		11,579	12,069
Transportation Logistics
Segment Reporting Information [Line Items]
Revenue		1,137,745	1,154,532
Gross revenue		1,137,745	1,154,532
Purchased transportation		897,878	905,521
Commissions to agents		93,314	97,282
Other operating costs, net of gains on asset sales/dispositions		11,829	14,859
Insurance and claims		33,856	26,853
Selling, general and administrative		59,426	53,194
Depreciation and amortization		12,226	14,142
Operating income		29,216	42,681
Goodwill		40,881	42,381
Transportation Logistics | Related Party [Member]
Segment Reporting Information [Line Items]
Revenue		0	0
Insurance
Segment Reporting Information [Line Items]
Revenue		14,757	16,511
Gross revenue		26,336	28,580
Investment income		3,598	3,412
Insurance and claims		17,575	11,484
Selling, general and administrative		2,156	3,228
Operating income		10,203	17,280
Insurance | Related Party [Member]
Segment Reporting Information [Line Items]
Revenue		$ 11,579	$ 12,069

[1] Interest and debt (income) expense includes (1) interest income earned on cash balances held by the transportation logistics segment of $1,668 and $2,500 in the 2025 and 2024 thirteen-week periods, respectively and (2) consolidated total interest expense of $1,509 and $889 in the 2025 and 2024 thirteen-week periods, respectively.