|
Fair Value (Details) (USD $)
In Thousands, unless otherwise specified |
Apr. 30, 2013
|
Jan. 31, 2013
|
|---|---|---|
| Assets: | ||
| Total assets measured at fair value | $ 56,314 | $ 66,269 |
|
Money market funds
|
||
| Assets: | ||
| Total assets measured at fair value | 28,080 | 32,522 |
|
Commercial paper
|
||
| Assets: | ||
| Total assets measured at fair value | 21,845 | 24,092 |
|
Corporate debt securities
|
||
| Assets: | ||
| Total assets measured at fair value | 6,389 | 9,655 |
|
Quoted Prices in Active Markets for Identical Instruments (Level 1)
|
||
| Assets: | ||
| Total assets measured at fair value | 28,080 | 32,522 |
|
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Money market funds
|
||
| Assets: | ||
| Total assets measured at fair value | 28,080 | 32,522 |
|
Significant Other Observable Inputs (Level 2)
|
||
| Assets: | ||
| Total assets measured at fair value | 28,234 | 33,747 |
|
Significant Other Observable Inputs (Level 2) | Commercial paper
|
||
| Assets: | ||
| Total assets measured at fair value | 21,845 | 24,092 |
|
Significant Other Observable Inputs (Level 2) | Corporate debt securities
|
||
| Assets: | ||
| Total assets measured at fair value | 6,389 | 9,655 |
|
Total
|
||
| Assets: | ||
| Total assets measured at fair value | 56,314 | 66,269 |
|
Total | Money market funds
|
||
| Assets: | ||
| Total assets measured at fair value | 28,080 | 32,522 |
|
Total | Commercial paper
|
||
| Assets: | ||
| Total assets measured at fair value | 21,845 | 24,092 |
|
Total | Corporate debt securities
|
||
| Assets: | ||
| Total assets measured at fair value | $ 6,389 | $ 9,655 |