Schedule II - Valuation And Qualifying Accounts (Details) - USD ($)	12 Months Ended
	Jan. 26, 2020	Jan. 27, 2019	Jan. 28, 2018
Change in Valuation Allowances and Reserves [Roll Forward]
Accrued liabilities	$ 50,632,000	$ 68,462,000
Allowance for doubtful accounts and other sales allowances
Change in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	774,000	9,089,000	$ 8,230,000
Additions	4,000	129,000	11,366,000
Deductions	(145,000)	(2,055,000)	(10,507,000)
Balance at End of Year	633,000	774,000	9,089,000
ASU 2014-09 | Allowance for doubtful accounts and other sales allowances
Change in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year		2,700,000
Balance at End of Year			$ 2,700,000
Previously Reported | Allowance for doubtful accounts and other sales allowances
Change in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	774,000
Balance at End of Year		$ 774,000
Restatement Adjustment | ASU 2014-09
Change in Valuation Allowances and Reserves [Roll Forward]
Accrued liabilities	7,400,000
Restatement Adjustment | ASU 2014-09 | Allowance for doubtful accounts and other sales allowances
Change in Valuation Allowances and Reserves [Roll Forward]
Balance at End of Year	$ (6,400,000)