Leases - Lease Cost and Supplemental Balance Sheet Information (Details) $ in Thousands	3 Months Ended
	Apr. 27, 2019 USD ($)
Leases [Abstract]
Lease cost under long-term operating leases	$ 8,331
Lease cost under short-term operating leases	8,406
Variable lease cost under short-term and long-term operating leases	1,210
Total lease cost	$ 17,947
Operating Lease, Weighted Average Remaining Lease Term	3 years 4 months 24 days
Weighted average discount rate (percent)	5.30%