Leases - Lease Cost and Supplemental Balance Sheet Information (Details) $ in Thousands	12 Months Ended
	Jan. 25, 2020 USD ($)
Leases [Abstract]
Lease cost under long-term operating leases	$ 33,799
Lease cost under short-term operating leases	34,111
Variable lease cost under short-term and long-term operating leases	4,183
Total lease cost	$ 72,093
Weighted average remaining lease term	3 years 3 months 18 days
Weighted average discount rate	5.20%