Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 26, 2020
Leases [Abstract]
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other assets	Other assets
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued liabilities	Accrued liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other long-term liabilities	Other long-term liabilities
Right-of-use assets	$ 16,337	$ 10,958
Lease liabilities	3,975	3,273
Operating lease liabilities in "Other long-term liabilities"	13,172	8,185
Total operating lease liabilities	$ 17,147	$ 11,458