Information Regarding Reportable Business Segments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Segment Reporting Information [Line Items]
External revenue from continuing operations	$ 3,321,091	$ 3,184,790	$ 2,664,780
Internal revenue	31,342	28,164	28,811
Investment income	1,396	1,381	1,475
Interest and debt expense from continuing operations	2,949	3,177	3,211
Depreciation and amortization from continuing operations	29,102	27,575	27,667
Operating income from continuing operations	241,706	224,372	176,590
Expenditures on long-lived assets from continuing operations	4,804	10,539	6,373
Goodwill	31,134	31,134	31,134
Capital lease additions	49,491	47,232	49,138
Total assets	998,070	1,044,212	970,696
Transportation Logistics
Segment Reporting Information [Line Items]
External revenue from continuing operations	3,276,677	3,145,413	2,628,225
Interest and debt expense from continuing operations	2,949	3,177	3,211
Depreciation and amortization from continuing operations	29,102	27,575	27,667
Operating income from continuing operations	207,883	193,914	151,188
Expenditures on long-lived assets from continuing operations	4,804	10,539	6,373
Goodwill	31,134	31,134	31,134
Capital lease additions	49,491	47,232	49,138
Total assets	849,102	917,789	754,904
Insurance
Segment Reporting Information [Line Items]
External revenue from continuing operations	44,414	39,377	36,555
Internal revenue	31,342	28,164	28,811
Investment income	1,396	1,381	1,475
Operating income from continuing operations	33,823	30,458	25,402
Total assets	$ 148,968	$ 126,423	$ 215,792