v3.3.1.900
Investments (Details) - USD ($)
$ in Thousands
12 Months Ended
Jan. 30, 2016
Jan. 31, 2015
Schedule of Investments, Reported Amounts, by Category [Line Items]    
Available-for-sale Securities, Amortized Cost Basis $ 71,953  
Current available for sale Securities Unrecognized Holding Gain 477 $ 0
Current Available for Sale Securities Unrecognized Holding Loss (435) 0
Short-term investments 226,027 171,201
Long-term investments 71,953 216,756
Long-Term Available for Sale Securities Unrecognized Holding Gain 22 0
Long-Term Available for Sale Securities Unrecognized Holding Loss (222) 0
Held-to-maturity Securities, Fair Value   216,810
Investments, Fair Value Disclosure 226,027 171,268
Investment disclosure [Abstract]    
Gross unrealized gains on short-term investments 0 117
Gross unrealized losses on short-term investments 0 (50)
Gross unrealized gains from long-term held-to-maturity investments 0 371
Gross unrealized losses on long-term held-to-maturity investments 0 (317)
Held-to-maturity Securities [Member] | Amortized cost    
Schedule of Investments, Reported Amounts, by Category [Line Items]    
Short-term investments 0 154,054
Long-term investments 0 216,756
Available-for-sale Securities [Member] | Carrying value    
Schedule of Investments, Reported Amounts, by Category [Line Items]    
Short-term investments 225,985 17,147
Long-term investments $ 72,153 $ 0