Financial Instruments - Schedule of Gross Unrealized Losses and Fair Values for Investments that were in Continuous Unrealized Loss Position for Less Than 12 Months, Aggregated by Investments Category (Details) - USD ($)	12 Months Ended
	Feb. 02, 2020	Jan. 31, 2019	Jan. 31, 2021
Fair Value Disclosures [Abstract]
Impairment charge for unrealized losses	$ 0	$ 0
Credit losses			$ 0
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less then 12 months	14,689,000		41,297,000
Unrealized Loss, Less then 12 months	(4,000)		(34,000)
Fair Value Greater then 12 months	1,000,000		0
Unrealized Loss, Greater then 12 months	0		0
Fair Value Total	15,689,000		41,297,000
Unrealized Loss Total	(4,000)		(34,000)
US Government Debt Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less then 12 months	0		8,301,000
Unrealized Loss, Less then 12 months	0		(1,000)
Fair Value Greater then 12 months	1,000,000		0
Unrealized Loss, Greater then 12 months	0		0
Fair Value Total	1,000,000		8,301,000
Unrealized Loss Total	0		(1,000)
U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less then 12 months	4,998,000
Unrealized Loss, Less then 12 months	(3,000)
Fair Value Greater then 12 months	0
Unrealized Loss, Greater then 12 months	0
Fair Value Total	4,998,000
Unrealized Loss Total	(3,000)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less then 12 months	9,691,000		32,996,000
Unrealized Loss, Less then 12 months	(1,000)		(33,000)
Fair Value Greater then 12 months	0		0
Unrealized Loss, Greater then 12 months	0		0
Fair Value Total	9,691,000		32,996,000
Unrealized Loss Total	$ (1,000)		$ (33,000)