|
Fair Value Measurements (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified |
Oct. 31, 2012
|
Jan. 31, 2012
|
|---|---|---|
| Fair Value Measurements | ||
| Preferred stock warrants | $ (2,133) | |
| Assets: | ||
| Restricted cash | 514 | |
| Liabilities: | ||
| Preferred stock warrants | (2,133) | |
| Net asset value per share of money market funds (in dollars per share) | $ 1 | |
|
Recurring basis | Level 1
|
||
| Fair Value Measurements | ||
| Money market funds | 250,732 | 20,142 |
| Assets: | ||
| Total | 250,732 | 20,142 |
|
Recurring basis | Level 3
|
||
| Fair Value Measurements | ||
| Preferred stock warrants | (2,133) | |
| Liabilities: | ||
| Preferred stock warrants | (2,133) | |
|
Recurring basis | Total
|
||
| Fair Value Measurements | ||
| Money market funds | 250,732 | 20,142 |
| Preferred stock warrants | (2,133) | |
| Assets: | ||
| Cash and cash equivalents | 250,732 | 19,499 |
| Prepaid expenses and other current assets | 129 | |
| Restricted cash | 514 | |
| Total | 250,732 | 20,142 |
| Liabilities: | ||
| Preferred stock warrants | $ (2,133) |