Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 27, 2019	Jan. 26, 2019
Property, Plant and Equipment [Line Items]
Total	$ 1,117,600	$ 1,073,379
Less: accumulated depreciation	(695,336)	(648,628)
Property and equipment, net	422,264	424,751
Land
Property, Plant and Equipment [Line Items]
Total	4,024	4,359
Buildings
Property, Plant and Equipment [Line Items]
Total	$ 12,882	13,555
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	10 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	35 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total	$ 16,979	16,185
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	1 year
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	10 years
Vehicles
Property, Plant and Equipment [Line Items]
Total	$ 614,128	589,741
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	1 year
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	5 years
Computer hardware and software
Property, Plant and Equipment [Line Items]
Total	$ 147,524	140,327
Computer hardware and software | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	1 year
Computer hardware and software | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	7 years
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Total	$ 13,396	12,804
Office furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	1 year
Office furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	10 years
Equipment and machinery
Property, Plant and Equipment [Line Items]
Total	$ 308,667	$ 296,408
Equipment and machinery | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	1 year
Equipment and machinery | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (Years)	10 years