Income Taxes - Reconciliation of the Provision for Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 29, 2018	Jan. 27, 2019	Jan. 28, 2018	Jan. 29, 2017
Income Tax Disclosure [Abstract]
Federal income tax at statutory rate		$ 13,223	$ 20,222	$ 25,571
State income taxes, net of federal benefit		(55)	(159)	0
Foreign taxes differential		2,910	(8,698)	(12,074)
Tax credits generated		(3,344)	(3,278)	(2,864)
Changes in valuation allowance	$ (15,800)	(23,029)	(41,911)	5,578
Non-taxable gain on sale		0	0	(2,978)
Changes in uncertain tax positions		2,219	1,538	1,047
Equity compensation		1,849	(8,333)	2,553
Permanent differences		0	264	448
Revaluation of deferred tax assets and liabilities		1,164	299	266
Impact of US Tax Reform		1,904	65,442	0
Other		3,075	(2,195)	852
(Benefit) Provision for income taxes		(84)	$ 23,191	$ 18,399
Increase to general business credits		5,000
Reduction to foreign tax credits		6,900
Expense due to the estimated impact of the transition tax, net of foreign tax credits generated		$ 66,500