Investments (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Oct. 28, 2017	Oct. 29, 2016	Jan. 28, 2017
Schedule of Investments, Reported Amounts, by Category [Line Items]
Short-term investments	$ 180,066	$ 78,512	$ 98,530
Long-term investments	0	76,126	77,904
Current available for sale Securities Unrecognized Holding Gain	47	156	101
Long-Term Available for Sale Securities Unrecognized Holding Gain	0	29	133
Current Available for Sale Securities Unrecognized Holding Loss	(512)	(141)	(364)
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax	0	(109)	(111)
Carrying value | Available-for-sale Securities [Member]
Schedule of Investments, Reported Amounts, by Category [Line Items]
Short-term investments	180,531	78,497	98,793
Long-term investments	$ 0	$ 76,206	$ 77,882