| Investments |
Investments The following tables summarize the Company’s investments (in thousands): | | | | | | | | | | | | | | | | | | May 5, 2018 | | Amortized Cost | | Gross Unrealized Gains | | Gross Unrealized Losses | | Estimated Fair Value | Short-term investments: | | | | | | | | Available-for-sale: | | | | | | | | U.S. government and agency debt | $ | 194,192 |
| | $ | 32 |
| | $ | (521 | ) | | $ | 193,703 |
| Foreign government and agency debt | 1,810 |
| | — |
| | (14 | ) | | 1,796 |
| Municipal debt securities | 1,315 |
| | — |
| | (1 | ) | | 1,314 |
| Corporate debt securities | 388,194 |
| | 446 |
| | (2,158 | ) | | 386,482 |
| Asset backed securities | 28,954 |
| | — |
| | (196 | ) | | 28,758 |
| Held-to-maturity: | | | | | | | | Time deposits | 100,000 |
| | — |
| | — |
| | 100,000 |
| Total short-term investments | 714,465 |
| | 478 |
| | (2,890 | ) | | 712,053 |
| Total investments | $ | 714,465 |
| | $ | 478 |
| | $ | (2,890 | ) | | $ | 712,053 |
|
| | | | | | | | | | | | | | | | | | February 3, 2018 | | Amortized Cost | | Gross Unrealized Gains | | Gross Unrealized Losses | | Estimated Fair Value | Short-term investments: | | | | | | | | Available-for-sale: | | | | | | | | U.S. government and agency debt | $ | 248,336 |
| | $ | 49 |
| | $ | (644 | ) | | $ | 247,741 |
| Foreign government and agency debt | 7,004 |
| | — |
| | (17 | ) | | 6,987 |
| Municipal debt securities | 2,734 |
| | — |
| | (6 | ) | | 2,728 |
| Corporate debt securities | 504,609 |
| | 469 |
| | (1,999 | ) | | 503,079 |
| Asset backed securities | 42,429 |
| | 3 |
| | (177 | ) | | 42,255 |
| Held-to-maturity: | | | | | | | | Time deposits | 150,000 |
| | — |
| | — |
| | 150,000 |
| Total short-term investments | 955,112 |
| | 521 |
| | (2,843 | ) | | 952,790 |
| Total investments | $ | 955,112 |
| | $ | 521 |
| | $ | (2,843 | ) | | $ | 952,790 |
|
Short-term, highly liquid investments of $392.1 million and $267.6 million as of May 5, 2018 and February 3, 2018, respectively, included in cash and cash equivalents on the accompanying consolidated balance sheets, are not included in the tables above because the gross unrealized gains and losses were immaterial as the carrying values approximate fair value due to the short term maturity of such investments. Gross realized gains and gross realized losses on sales of available-for-sale securities are presented in the following tables (in thousands): | | | | | | | | | | Three Months Ended | | May 5,
2018 | | April 29,
2017 | Gross realized gains | $ | 2 |
| | $ | 69 |
| Gross realized losses | (862 | ) | | (44 | ) | Total net realized gains (losses) | $ | (860 | ) | | $ | 25 |
|
The contractual maturities of available-for-sale securities are presented in the following tables (in thousands): | | | | | | | | | | | | | | | | | | May 5, 2018 | | February 3, 2018 | | Amortized Cost | | Estimated Fair Value | | Amortized Cost | | Estimated Fair Value | Due in one year or less | $ | 445,026 |
| | $ | 444,314 |
| | $ | 554,247 |
| | $ | 553,866 |
| Due between one and five years | 269,439 |
| | 267,740 |
| | 400,866 |
| | 398,924 |
| Due over five years | — |
| | — |
| | — |
| | — |
| | $ | 714,465 |
| | $ | 712,054 |
| | $ | 955,113 |
| | $ | 952,790 |
|
For individual securities that have been in a continuous unrealized loss position, the fair value and gross unrealized loss for these securities, aggregated by investment category and length of time in an unrealized position, are presented in the following tables (in thousands): | | | | | | | | | | | | | | | | | | | | | | | | | | May 5, 2018 | | Less than 12 months | | 12 months or more | | Total | | Fair Value | | Unrealized Loss | | Fair Value | | Unrealized Loss | | Fair Value | | Unrealized Loss | U.S. government and agency debt | $ | 123,181 |
| | $ | (219 | ) | | $ | 45,137 |
| | $ | (302 | ) | | $ | 168,318 |
| | $ | (521 | ) | Foreign government and agency debt | — |
| | — |
| | 1,796 |
| | (13 | ) | | 1,796 |
| | (13 | ) | Municipal debt securities | 1,314 |
| | (1 | ) | | — |
| | — |
| | 1,314 |
| | (1 | ) | Corporate debt securities | 195,971 |
| | (1,660 | ) | | 39,594 |
| | (498 | ) | | 235,565 |
| | (2,158 | ) | Asset backed securities | 26,146 |
| | (158 | ) | | 2,161 |
| | (39 | ) | | 28,307 |
| | (197 | ) | Total securities | $ | 346,612 |
| | $ | (2,038 | ) | | $ | 88,688 |
| | $ | (852 | ) | | $ | 435,300 |
| | $ | (2,890 | ) | | | | | | | | | | | | | | | | | | | | | | | | | | February 3, 2018 | | Less than 12 months | | 12 months or more | | Total | | Fair Value | | Unrealized Loss | | Fair
Value | | Unrealized
Loss | | Fair
Value | | Unrealized
Loss | U.S. government and agency debt | $ | 148,538 |
| | $ | (298 | ) | | $ | 51,332 |
| | $ | (346 | ) | | $ | 199,870 |
| | $ | (644 | ) | Foreign government and agency debt | 3,993 |
| | (1 | ) | | 2,994 |
| | (16 | ) | | 6,987 |
| | (17 | ) | Municipal debt securities | 1,969 |
| | (6 | ) | | — |
| | — |
| | 1,969 |
| | (6 | ) | Corporate debt securities | 253,380 |
| | (1,514 | ) | | 46,805 |
| | (485 | ) | | 300,185 |
| | (1,999 | ) | Asset backed securities | 37,636 |
| | (145 | ) | | 2,167 |
| | (32 | ) | | 39,803 |
| | (177 | ) | Total securities | $ | 445,516 |
| | $ | (1,964 | ) | | $ | 103,298 |
| | $ | (879 | ) | | $ | 548,814 |
| | $ | (2,843 | ) |
As of May 5, 2018, for fixed income securities that were in unrealized loss positions, the Company has determined that (i) it does not have the intent to sell these investments, and (ii) it is not more likely than not that it will be required to sell any of these investments before recovery of the amortized cost basis. In addition, as of May 5, 2018, the Company anticipates that it will recover the amortized cost basis of such fixed income securities and has determined that no other-than-temporary impairments associated with credit losses were required to be recognized during the three months ended May 5, 2018. |