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Commitments and Contingencies - Additional Information (Detail)					1 Months Ended	3 Months Ended	9 Months Ended
	Feb. 21, 2018 Defendant CoDefendant	Oct. 30, 2017 USD ($)	Oct. 16, 2017 USD ($)	Jul. 21, 2017 USD ($)	Feb. 28, 2018 USD ($)	Sep. 29, 2018 USD ($)	Sep. 29, 2018 USD ($) Employee
Concentration Risk [Line Items]
Accrual insurance and claims						$ 1,800,000	$ 1,800,000
Lawsuit filing date							June 11, 2015
Damages sought from debtor relating to unpaid freight charges							$ 1,900,000
Loss contingency damages value ignored		$ 1,900,000
United States, Canada and Colombia [Member] \| Workforce Subject to Collective Bargaining Arrangements [Member] \| Unionized Employees Concentration Risk [Member]
Concentration Risk [Line Items]
Percentage of revenues from major customers							27.00%
Number of employees subject to contracts that expire in 2018 \| Employee							0
Mexico [Member] \| Workforce Subject to Collective Bargaining Arrangements [Member] \| Unionized Employees Concentration Risk [Member]
Concentration Risk [Line Items]
Percentage of revenues from major customers							94.00%
Damages from Debtor Relating to Unpaid Freight Charges [Member]
Concentration Risk [Line Items]
Damages awarded value				$ 1,900,000
Dalton Logistics, Inc [Member]
Concentration Risk [Line Items]
Loss contingency damages awarded value to defendant		$ 5,700,000		$ 5,700,000
Minimum [Member]
Concentration Risk [Line Items]
Estimated possible range of financial exposure						2,000,000	$ 0
Maximum [Member]
Concentration Risk [Line Items]
Estimated possible range of financial exposure						$ 9,000,000	$ 5,700,000
Denton v. UACL, et al [Member]
Concentration Risk [Line Items]
Loss contingency damages awarded value to defendant			$ 54,200,000
Verdict compensatory damages			19,200,000
Verdict punitive damages			35,000,000
Insurance coverage available for reimbursement			1,000,000
Accrual insurance and claims			18,200,000
Denton v. UACL, et al [Member] \| Minimum [Member]
Concentration Risk [Line Items]
Estimated possible range of financial exposure			18,200,000
Denton v. UACL, et al [Member] \| Maximum [Member]
Concentration Risk [Line Items]
Estimated possible range of financial exposure			$ 53,200,000
Ford Motor Company [Member]
Concentration Risk [Line Items]
Damages awarded value					$ 76,000,000
Ford Motor Company [Member] \| Subsidiary Defendants [Member]
Concentration Risk [Line Items]
Loss contingency number of defendants \| Defendant	2
Ford Motor Company [Member] \| Other Parties [Member]
Concentration Risk [Line Items]
Loss contingency number of co-defendants \| CoDefendant	2