Information Regarding Reportable Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Segment Reporting Information [Line Items]
External revenue from continuing operations	$ 3,184,790us-gaap_Revenues	$ 2,664,780us-gaap_Revenues	$ 2,770,799us-gaap_Revenues
Internal revenue	28,164us-gaap_RevenueFromRelatedParties	28,811us-gaap_RevenueFromRelatedParties	28,446us-gaap_RevenueFromRelatedParties
Investment income	1,381us-gaap_InterestIncomeOperating	1,475us-gaap_InterestIncomeOperating	1,563us-gaap_InterestIncomeOperating
Interest and debt expense from continuing operations	3,177us-gaap_InterestAndDebtExpense	3,211us-gaap_InterestAndDebtExpense	3,110us-gaap_InterestAndDebtExpense
Depreciation and amortization from continuing operations	27,575us-gaap_DepreciationAndAmortization	27,667us-gaap_DepreciationAndAmortization	25,213us-gaap_DepreciationAndAmortization
Operating income from continuing operations	224,372us-gaap_OperatingIncomeLoss	176,590us-gaap_OperatingIncomeLoss	200,739us-gaap_OperatingIncomeLoss
Expenditures on long-lived assets from continuing operations	10,539	6,373	5,388
Goodwill	31,134us-gaap_Goodwill	31,134us-gaap_Goodwill	57,470us-gaap_Goodwill
Capital lease additions	47,232us-gaap_CapitalLeaseObligationsIncurred	49,138us-gaap_CapitalLeaseObligationsIncurred	43,077us-gaap_CapitalLeaseObligationsIncurred
Total assets	1,044,212us-gaap_Assets	970,696us-gaap_Assets	879,421us-gaap_Assets
Transportation Logistics
Segment Reporting Information [Line Items]
External revenue from continuing operations	3,145,413	2,628,225	2,734,938
Interest and debt expense from continuing operations	3,177	3,211	3,110
Depreciation and amortization from continuing operations	27,575	27,667	25,213
Operating income from continuing operations	193,914	151,188	167,626
Expenditures on long-lived assets from continuing operations	10,539	6,373	5,388
Goodwill	31,134	31,134	57,470
Capital lease additions	47,232	49,138	43,077
Total assets	917,789	754,904	708,233
Insurance
Segment Reporting Information [Line Items]
External revenue from continuing operations	39,377	36,555	35,861
Internal revenue	28,164	28,811	28,446
Investment income	1,381	1,475	1,563
Operating income from continuing operations	30,458	25,402	33,113
Total assets	$ 126,423	$ 215,792	$ 171,188

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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The increase during the period in capital lease obligations due to entering into new capital leases.

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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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Interest and debt related expenses associated with nonoperating financing activities of the entity.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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