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Fair Value Measurements - Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) (USD $)
In Thousands, unless otherwise specified |
Jul. 31, 2014
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Jan. 31, 2014
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|---|---|---|
| Financial assets: | ||
| Cash and cash equivalents | $ 95,047 | $ 112,271 |
| Available for sale marketable securities: | ||
| Marketable securities, short-term | 6,038 | 5,555 |
| Non-current marketable securities: | ||
| Marketable securities, long-term | 8,279 | 6,814 |
| Total | 110,872 | 128,103 |
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Money Market Accounts [Member]
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| Financial assets: | ||
| Cash and cash equivalents | 1,508 | 3,463 |
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U.S. Treasury Notes and Bonds Conventional [Member]
|
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| Available for sale marketable securities: | ||
| Marketable securities, short-term | 2,511 | 3,545 |
| Non-current marketable securities: | ||
| Marketable securities, long-term | 2,006 | |
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U.S. Government Agency Issues Short Term [Member]
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| Available for sale marketable securities: | ||
| Marketable securities, short-term | 3,527 | 2,010 |
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U.S. Government Agency Issues Long Term [Member]
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| Non-current marketable securities: | ||
| Marketable securities, long-term | 6,273 | 6,814 |
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Fair Value, Inputs, Level 1 [Member]
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| Financial assets: | ||
| Cash and cash equivalents | 95,047 | 112,271 |
| Non-current marketable securities: | ||
| Total | 101,072 | 119,279 |
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Fair Value, Inputs, Level 1 [Member] | Money Market Accounts [Member]
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| Financial assets: | ||
| Cash and cash equivalents | 1,508 | 3,463 |
|
Fair Value, Inputs, Level 1 [Member] | U.S. Treasury Notes and Bonds Conventional [Member]
|
||
| Available for sale marketable securities: | ||
| Marketable securities, short-term | 2,511 | 3,545 |
| Non-current marketable securities: | ||
| Marketable securities, long-term | 2,006 | |
|
Fair Value, Inputs, Level 1 [Member] | U.S. Government Agency Issues Short Term [Member]
|
||
| Available for sale marketable securities: | ||
| Marketable securities, short-term | ||
|
Fair Value, Inputs, Level 1 [Member] | U.S. Government Agency Issues Long Term [Member]
|
||
| Non-current marketable securities: | ||
| Marketable securities, long-term | ||
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Fair Value, Inputs, Level 2 [Member]
|
||
| Financial assets: | ||
| Cash and cash equivalents | ||
| Non-current marketable securities: | ||
| Total | 9,800 | 8,824 |
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Fair Value, Inputs, Level 2 [Member] | Money Market Accounts [Member]
|
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| Financial assets: | ||
| Cash and cash equivalents | ||
|
Fair Value, Inputs, Level 2 [Member] | U.S. Treasury Notes and Bonds Conventional [Member]
|
||
| Available for sale marketable securities: | ||
| Marketable securities, short-term | ||
| Non-current marketable securities: | ||
| Marketable securities, long-term | ||
|
Fair Value, Inputs, Level 2 [Member] | U.S. Government Agency Issues Short Term [Member]
|
||
| Available for sale marketable securities: | ||
| Marketable securities, short-term | 3,527 | 2,010 |
|
Fair Value, Inputs, Level 2 [Member] | U.S. Government Agency Issues Long Term [Member]
|
||
| Non-current marketable securities: | ||
| Marketable securities, long-term | 6,273 | 6,814 |
|
Fair Value, Inputs, Level 3 [Member]
|
||
| Financial assets: | ||
| Cash and cash equivalents | ||
| Non-current marketable securities: | ||
| Total | ||
|
Fair Value, Inputs, Level 3 [Member] | Money Market Accounts [Member]
|
||
| Financial assets: | ||
| Cash and cash equivalents | ||
|
Fair Value, Inputs, Level 3 [Member] | U.S. Treasury Notes and Bonds Conventional [Member]
|
||
| Available for sale marketable securities: | ||
| Marketable securities, short-term | ||
| Non-current marketable securities: | ||
| Marketable securities, long-term | ||
|
Fair Value, Inputs, Level 3 [Member] | U.S. Government Agency Issues Short Term [Member]
|
||
| Available for sale marketable securities: | ||
| Marketable securities, short-term | ||
|
Fair Value, Inputs, Level 3 [Member] | U.S. Government Agency Issues Long Term [Member]
|
||
| Non-current marketable securities: | ||
| Marketable securities, long-term |