Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2016	Jan. 30, 2016	May. 02, 2015
Schedule of Investments, Reported Amounts, by Category [Line Items]
Short-term investments	$ 97,612	$ 226,027	$ 128,705
Long-term investments	80,456	71,953	120,724
Current available for sale Securities Unrecognized Holding Gain	411	477	38
Long-Term Available for Sale Securities Unrecognized Holding Gain	22	22	38
Current Available for Sale Securities Unrecognized Holding Loss	(35)	(435)	(112)
Available-for-sale Securities, Change in Net Unrealized Holding Gain (Loss), Net of Tax	(314)	(222)	(325)
Investment disclosure [Abstract]
Short-term investments(a)	97,612	226,027	128,705
Carrying value | Available-for-sale Securities [Member]
Schedule of Investments, Reported Amounts, by Category [Line Items]
Short-term investments	97,236	225,985	128,779
Long-term investments	$ 80,748	$ 72,153	$ 121,011