Leases - Lease Cost and Supplemental Balance Sheet Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jul. 27, 2019 USD ($)	Jul. 27, 2019 USD ($)
Leases [Abstract]
Lease cost under long-term operating leases	$ 8,292	$ 16,712
Lease cost under short-term operating leases	8,608	16,994
Variable lease cost under short-term and long-term operating leases	1,131	2,272
Total lease cost	$ 18,031	$ 35,978
Operating Lease, Weighted Average Remaining Lease Term	3 years 4 months 24 days	3 years 4 months 24 days
Weighted average discount rate (percent)	5.30%	5.30%