Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 26, 2020 USD ($) Segment $ / shares shares	Dec. 28, 2019 USD ($) $ / shares shares	Dec. 29, 2018 USD ($) shares
Significant Accounting Policies [Line Items]
Number of reporting units | Segment	2
Stock options excluded from calculation of diluted earnings per share, antidilutive | shares	0	0	0
Dividends payable per share | $ / shares	$ 2.00	$ 2.00
Dividend payable date	Jan. 22, 2021	Jan. 24, 2020
Dividend record date	Jan. 08, 2021	Jan. 10, 2020
Dividends payable	$ 76,770,000	$ 78,947,000
Dividend announced date	Dec. 08, 2020	Dec. 10, 2019
Self Insurance Reserve, Current	$ 149,774,000	$ 44,532,000
Retained earnings	$ 2,046,238,000	$ 1,962,161,000
Accounting Standards Update 2014-09 | Retained Earnings | Revision of Prior Period, Accounting Standards Update, Adjustment [Member]
Significant Accounting Policies [Line Items]
Retained earnings			$ 773,000
Buildings And Improvements
Significant Accounting Policies [Line Items]
Depreciated life	30 years
Trailing Equipment | Maximum
Significant Accounting Policies [Line Items]
Depreciated life	10 years
Trailing Equipment | Minimum
Significant Accounting Policies [Line Items]
Depreciated life	7 years
Hardware And Software | Maximum
Significant Accounting Policies [Line Items]
Depreciated life	7 years
Hardware And Software | Minimum
Significant Accounting Policies [Line Items]
Depreciated life	3 years
Commercial Trucking Claims
Significant Accounting Policies [Line Items]
Company retained aggregate liability	$ 10,000,000
Self insurance excess value maintain third party	5,000,000
Increase decrease in the provision for third party insurance premium	$ 14,000,000
Percentage increase decrease in the third party insurance premiums	170.00%
Self Insurance Reserve, Current	$ 104,000,000
Commercial Trucking Claims | Initial Excess Policy [Member]
Significant Accounting Policies [Line Items]
Company retained liability per claim	5,000,000
Additional premium	3,500,000
Commercial Trucking Claims | Third Party Insurance [Member]
Significant Accounting Policies [Line Items]
Company retained aggregate liability	104,000,000
Self insurance excess value maintain third party	5,000,000
Commercial Trucking Claims | Third Party Insurance [Member] | Excess Coverage Policy [Member]
Significant Accounting Policies [Line Items]
Self insurance excess value maintain third party	10,000,000
Commercial Trucking Claims | Retained Liability Maximum In Aggregate For Three Year Policy From May 1 2019 To April 30 2022 [Member] | Initial Excess Policy [Member]
Significant Accounting Policies [Line Items]
Company retained aggregate liability	10,000,000
Commercial Trucking Claims | Maximum
Significant Accounting Policies [Line Items]
Company retained liability per claim	10,000,000
Commercial Trucking Claims | Maximum | Initial Excess Policy [Member]
Significant Accounting Policies [Line Items]
Company retained aggregate liability	15,000,000
Commercial Trucking Claims | Maximum | Additional Retained Liability, Maximum in Aggregate, for three year policy that goes May 1, 2019 through April 30, 2022
Significant Accounting Policies [Line Items]
Company retained term aggregate	20,000,000
Commercial Trucking Claims | Minimum
Significant Accounting Policies [Line Items]
Company retained liability per claim	5,000,000
Commercial Trucking Claims | Minimum | Initial Excess Policy [Member]
Significant Accounting Policies [Line Items]
Company retained aggregate liability	5,000,000
Commercial Trucking Claims | Minimum | Third Party Insurance [Member]
Significant Accounting Policies [Line Items]
Company retained liability per claim	5,000,000
Commercial Trucking Claims | Other Assets [Member]
Significant Accounting Policies [Line Items]
Claims receivable from third party insurance companies in excess of self insurance retention	104,000,000
General Liability Claim
Significant Accounting Policies [Line Items]
Company retained liability per claim	1,000,000
Workers' Compensation Claim
Significant Accounting Policies [Line Items]
Company retained liability per claim	250,000
Workers' Compensation Claim | BCO Independent Contractor
Significant Accounting Policies [Line Items]
Company retained liability per claim	750,000
Cargo Claim
Significant Accounting Policies [Line Items]
Company retained liability per claim	250,000
Occupational Reinsurance Claims One [Member] | BCO Independent Contractor
Significant Accounting Policies [Line Items]
Company retained liability per claim	500,000
Occupational Reinsurance Claims Two [Member] | BCO Independent Contractor
Significant Accounting Policies [Line Items]
Company retained liability per claim	1,000,000
Occupational Reinsurance Claims Three [Member] | BCO Independent Contractor
Significant Accounting Policies [Line Items]
Company retained liability per claim	$ 2,000,000