v3.8.0.1
Investments - Summary of Investments (Details) - USD ($)
$ in Thousands
May 05, 2018
Feb. 03, 2018
Available-for-sale:    
Amortized Cost $ 714,465 $ 955,113
Estimated Fair Value 712,054 952,790
Held-to-maturity:    
Amortized Cost 714,465 955,112
Gross Unrealized Gains 478 521
Gross Unrealized Losses (2,890) (2,843)
Estimated Fair Value 712,053 952,790
Short-term, highly liquid investments 392,100 267,600
Total short-term investments    
Held-to-maturity:    
Amortized Cost 714,465 955,112
Gross Unrealized Gains 478 521
Gross Unrealized Losses (2,890) (2,843)
Estimated Fair Value 712,053 952,790
U.S. government and agency debt    
Available-for-sale:    
Amortized Cost 194,192 248,336
Gross Unrealized Gains 32 49
Gross Unrealized Losses (521) (644)
Estimated Fair Value 193,703 247,741
Foreign government and agency debt    
Available-for-sale:    
Amortized Cost 1,810 7,004
Gross Unrealized Gains 0 0
Gross Unrealized Losses (14) (17)
Estimated Fair Value 1,796 6,987
Municipal debt securities    
Available-for-sale:    
Amortized Cost 1,315 2,734
Gross Unrealized Gains 0 0
Gross Unrealized Losses (1) (6)
Estimated Fair Value 1,314 2,728
Corporate debt securities    
Available-for-sale:    
Amortized Cost 388,194 504,609
Gross Unrealized Gains 446 469
Gross Unrealized Losses (2,158) (1,999)
Estimated Fair Value 386,482 503,079
Asset backed securities    
Available-for-sale:    
Amortized Cost 28,954 42,429
Gross Unrealized Gains 0 3
Gross Unrealized Losses (196) (177)
Estimated Fair Value 28,758 42,255
Time deposits    
Held-to-maturity:    
Amortized Cost 100,000 150,000
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Value $ 100,000 $ 150,000