| Cash Equivalents and Marketable Securities | | | | | | | | | | | | | | | | | | | October 30, 2011 | | Amortized Cost | | Unrealized Gain | | Unrealized Loss | | Estimated Fair Value | | (In thousands) | Debt securities of United States government agencies | $ | 607,828 |
| | $ | 1,134 |
| | $ | (330 | ) | | $ | 608,632 |
| Corporate debt securities | 1,105,438 |
| | 2,840 |
| | (531 | ) | | 1,107,747 |
| Mortgage backed securities issued by United States government-sponsored enterprises | 141,189 |
| | 5,005 |
| | (31 | ) | | 146,163 |
| Money market funds | 36,296 |
| |
|
| |
|
| | 36,296 |
| Debt securities issued by United States Treasury | 430,233 |
| | 2,019 |
| | (505 | ) | | 431,747 |
| Total | $ | 2,320,984 |
| | $ | 10,998 |
| | $ | (1,397 | ) | | $ | 2,330,585 |
| Classified as: | |
| | |
| | |
| | |
| Cash equivalents | |
| | |
| | |
| | $ | 149,047 |
| Marketable securities | |
| | |
| | |
| | 2,181,538 |
| Total | |
| | |
| | |
| | $ | 2,330,585 |
|
| | | | | | | | | | | | | | | | | | January 30, 2011 | | Amortized Cost | | Unrealized Gain | | Unrealized Loss | | Estimated Fair Value | | (In thousands) | Debt securities of United States government agencies | $ | 531,789 |
| | $ | 1,034 |
| | $ | (226 | ) | | $ | 532,597 |
| Corporate debt securities | 925,226 |
| | 3,354 |
| | (208 | ) | | 928,372 |
| Mortgage backed securities issued by United States government-sponsored enterprises | 140,844 |
| | 4,599 |
| | (21 | ) | | 145,422 |
| Money market funds | 132,586 |
| | — |
| | — |
| | 132,586 |
| Debt securities issued by United States Treasury | 435,091 |
| | 1,939 |
| | (18 | ) | | 437,012 |
| Total | $ | 2,165,536 |
| | $ | 10,926 |
| | $ | (473 | ) | | $ | 2,175,989 |
| Classified as: | | | | | | | | Cash equivalents | | | | | | | $ | 350,787 |
| Marketable securities | | | | | | | 1,825,202 |
| Total | | | | | | | $ | 2,175,989 |
|
|
| Schedule of Cash Equivalents and Marketable Securities Available for Sale | | | | | | | | | | | | | | | | | | | October 30, 2011 | | January 30, 2011 | | Amortized Cost | | Estimated Fair Value | | Amortized Cost | | Estimated Fair Value | Less than one year | $ | 1,236,291 |
| | $ | 1,237,962 |
| | $ | 1,176,046 |
| | $ | 1,178,733 |
| Due in 1 - 5 years | 984,387 |
| | 988,574 |
| | 899,993 |
| | 904,926 |
| Mortgage-backed securities issued by government-sponsored enterprises not due at a single maturity date | 100,306 |
| | 104,049 |
| | 89,497 |
| | 92,330 |
| Total | $ | 2,320,984 |
| | $ | 2,330,585 |
| | $ | 2,165,536 |
| | $ | 2,175,989 |
|
|