| Fair Value Measurements |
Fair Value Measurements Fair value is the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability, in an orderly transaction between market participants at the measurement date. We minimize the use of unobservable inputs and use observable market data, if available, when determining fair value. We classify our inputs to measure fair value using the following three-level hierarchy: | | Level 1: | Quoted prices in active markets at the measurement date for identical assets and liabilities. |
| | Level 2: | Prices may be based upon quoted prices in active markets or inputs not quoted on active markets but are corroborated by market data. |
| | Level 3: | Unobservable inputs are used when little or no market data is available and reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. |
Financial assets and liabilities carried at fair value are classified below: | | | | | | | | | | | | | | | September 30, 2011 | | Level 1 | Level 2 | Level 3 | Total | | (in thousands) | Assets: | | | | | Investments held in supplemental retirement plan (1) | $ | 1,891 |
| $ | — |
| $ | — |
| $ | 1,891 |
| Money market funds (2) | 142,038 |
| — |
| — |
| 142,038 |
| Corporate bonds (3) | — |
| 176,958 |
| — |
| 176,958 |
| Municipal debt securities (3) | — |
| 472,201 |
| — |
| 472,201 |
| U.S. agency securities (2), (3) | 29,919 |
| — |
| — |
| 29,919 |
| Total | $ | 173,848 |
| $ | 649,159 |
| $ | — |
| $ | 823,007 |
|
| | (1) | These assets are included within prepaid expenses and other current assets and within other non-current assets. |
| | (2) | These assets are included within cash and cash equivalents. |
| | (3) | These assets are included within short-term investments and within long-term investments. |
| | | | | | | | | | | | | | | September 30, 2011 | | Level 1 | Level 2 | Level 3 | Total | | (in thousands) | Liabilities: | | | | | Investments held in supplemental retirement plan (1) | $ | 1,891 |
| $ | — |
| $ | — |
| $ | 1,891 |
| Total | $ | 1,891 |
| $ | — |
| $ | — |
| $ | 1,891 |
|
| | (1) | These liabilities are included within accrued compensation and benefits and within other non-current liabilities. |
| | | | | | | | | | | | | | | March 30, 2012 | | Level 1 | Level 2 | Level 3 | Total | | (in thousands) | Assets: | | | | | Investments held in supplemental retirement plan (1) | $ | 2,137 |
| $ | — |
| $ | — |
| $ | 2,137 |
| Money market funds (2) | 264,366 |
| — |
| — |
| 264,366 |
| Commercial paper (3) | — |
| 20,984 |
| — |
| 20,984 |
| Corporate bonds (4) | — |
| 125,092 |
| — |
| 125,092 |
| Municipal debt securities (4) | — |
| 389,371 |
| — |
| 389,371 |
| U.S. agency securities (4) | 25,092 |
| — |
| — |
| 25,092 |
| Total | $ | 291,595 |
| $ | 535,447 |
| $ | — |
| $ | 827,042 |
|
| | (1) | These assets are included within prepaid expenses and other current assets and within other non-current assets. |
| | (2) | These assets are included within cash and cash equivalents. |
| | (3) | These assets are included within short-term investments. |
| | (4) | These assets are included within short-term investments and within long-term investments. |
| | | | | | | | | | | | | | | March 30, 2012 | | Level 1 | Level 2 | Level 3 | Total | | (in thousands) | Liabilities: | | | | | Investments held in supplemental retirement plan (1) | $ | 2,137 |
| $ | — |
| $ | — |
| $ | 2,137 |
| Total | $ | 2,137 |
| $ | — |
| $ | — |
| $ | 2,137 |
|
| | (1) | These liabilities are included within accrued compensation and benefits and within other non-current liabilities. |
We base the fair value of our Level 1 financial instruments, which are traded in active markets, using quoted market prices for identical instruments. Our Level 1 financial instruments include money market funds, U.S. agency securities, U.S. government bonds, and mutual fund investments held in our supplemental retirement plan. We obtain the fair value of our Level 2 financial instruments from a professional pricing service, which may use quoted market prices for identical or comparable instruments, or model driven valuations using observable market data or inputs corroborated by observable market data. To validate the fair value determination provided by our primary pricing service, we perform quality controls over values received which include comparing our pricing service provider’s assessment of the fair values of our investment securities against the fair values of our investment securities obtained from another independent source, reviewing the pricing movement in the context of overall market trends, and reviewing trading information from our investment managers. In addition, we assess the inputs and methods used in determining the fair value in order to determine the classification of securities in the fair value hierarchy. We did not own any Level 3 financial assets or liabilities as of September 30, 2011 or March 30, 2012. |