Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 29, 2016	Jan. 30, 2016	Oct. 31, 2015
Schedule of Investments, Reported Amounts, by Category [Line Items]
Short-term investments	$ 78,512	$ 226,027	$ 0
Long-term investments	76,126	71,953	306,483
Current available for sale Securities Unrecognized Holding Gain	156	477	0
Long-Term Available for Sale Securities Unrecognized Holding Gain	29	22	207
Current Available for Sale Securities Unrecognized Holding Loss	(141)	(435)	0
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax	(109)	(222)	(516)
Investment disclosure [Abstract]
Short-term investments(a)	78,512	226,027	0
Carrying value | Available-for-sale Securities [Member]
Schedule of Investments, Reported Amounts, by Category [Line Items]
Short-term investments	78,497	225,985	0
Long-term investments	$ 76,206	$ 72,153	$ 306,792