Information Regarding Reportable Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 24, 2011	Jun. 25, 2011	Mar. 26, 2011	Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
Segment Reporting Information [Line Items]
External revenue	$ 691,256	$ 717,168	$ 735,973	$ 649,023	$ 717,522	$ 684,013	$ 675,561	$ 571,986	$ 2,793,420	$ 2,649,082	$ 2,400,170
Internal revenue									28,446	27,544	27,535
Investment income									1,563	1,705	1,558
Interest and debt expense									3,104	3,112	3,623
Depreciation and amortization									27,456	25,814	24,804
Operating income	49,535	54,379	58,789	43,150	50,950	49,533	48,670	34,092	205,853	183,245	139,971
Expenditures on long-lived assets									7,072	4,337	27,505
Goodwill	57,470				57,470				57,470	57,470	57,470
Capital lease additions									43,077	34,044	14,986
Total assets	879,421				808,449				879,421	808,449	683,882
Transportation Logistics
Segment Reporting Information [Line Items]
External revenue									2,757,559	2,614,739	2,366,032
Interest and debt expense									3,104	3,112	3,623
Depreciation and amortization									27,456	25,814	24,804
Operating income									172,740	156,354	116,512
Expenditures on long-lived assets									7,072	4,337	27,505
Goodwill	57,470				57,470				57,470	57,470	57,470
Capital lease additions									43,077	34,044	14,986
Total assets	708,233				647,002				708,233	647,002	576,334
Insurance
Segment Reporting Information [Line Items]
External revenue									35,861	34,343	34,138
Internal revenue									28,446	27,544	27,535
Investment income									1,563	1,705	1,558
Operating income									33,113	26,891	23,459
Total assets	$ 171,188				$ 161,447				$ 171,188	$ 161,447	$ 107,548