Information Regarding Reportable Business Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
External revenue	$ 892,829	$ 787,938	$ 775,223	$ 711,644	$ 848,602	$ 841,726	$ 868,383	$ 762,380	$ 3,167,634	$ 3,321,091	$ 3,184,790
Internal revenue									36,118	31,342	28,164
Investment income									1,502	1,396	1,381
Interest and debt expense									3,794	2,949	3,177
Depreciation and amortization									35,796	29,102	27,575
Operating income	63,765	$ 58,461	$ 53,093	$ 47,932	62,648	$ 63,980	$ 66,033	$ 49,045	223,251	241,706	224,372
Expenditures on long-lived assets									22,645	4,804	10,539
Goodwill	31,134				31,134				31,134	31,134	31,134
Capital lease additions									61,504	49,491	47,232
Total assets	1,096,591				991,518				1,096,591	991,518	1,037,616
Transportation Logistics
Segment Reporting Information [Line Items]
External revenue									3,121,210	3,276,677	3,145,413
Interest and debt expense									3,794	2,949	3,177
Depreciation and amortization									35,796	29,102	27,575
Operating income									187,813	207,883	193,914
Expenditures on long-lived assets									22,645	4,804	10,539
Goodwill	31,134				31,134				31,134	31,134	31,134
Capital lease additions									61,504	49,491	47,232
Total assets	913,667				842,550				913,667	842,550	911,193
Insurance
Segment Reporting Information [Line Items]
External revenue									46,424	44,414	39,377
Internal revenue									36,118	31,342	28,164
Investment income									1,502	1,396	1,381
Operating income									35,438	33,823	30,458
Total assets	$ 182,924				$ 148,968				$ 182,924	$ 148,968	$ 126,423