Fair Value Measurements - Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified
|
Oct. 31, 2013
|
Jan. 31, 2013
|
Financial assets: |
|
|
Cash and cash equivalents |
$ 109,648
|
$ 104,109
|
Available for sale marketable securities: |
|
|
U.S. government agency issues - Current |
3,021
|
6,104
|
Non-current marketable securities: |
|
|
U.S. government agency issues - Non current |
8,360
|
7,169
|
Total |
125,488
|
119,994
|
Other liabilities: |
|
|
Acquisition-related consideration |
|
5,656
|
Money Market Accounts [Member]
|
|
|
Financial assets: |
|
|
Cash and cash equivalents |
4,459
|
2,612
|
U.S. Government Agency Issues Short Term [Member]
|
|
|
Available for sale marketable securities: |
|
|
U.S. government agency issues - Current |
3,021
|
6,104
|
U.S. Government Agency Issues Long Term [Member]
|
|
|
Non-current marketable securities: |
|
|
U.S. government agency issues - Non current |
8,360
|
7,169
|
Fair Value, Inputs, Level 1 [Member]
|
|
|
Financial assets: |
|
|
Cash and cash equivalents |
109,648
|
104,109
|
Non-current marketable securities: |
|
|
Total |
125,488
|
119,994
|
Other liabilities: |
|
|
Acquisition-related consideration |
|
|
Fair Value, Inputs, Level 1 [Member] | Money Market Accounts [Member]
|
|
|
Financial assets: |
|
|
Cash and cash equivalents |
4,459
|
2,612
|
Fair Value, Inputs, Level 1 [Member] | U.S. Government Agency Issues Short Term [Member]
|
|
|
Available for sale marketable securities: |
|
|
U.S. government agency issues - Current |
3,021
|
6,104
|
Fair Value, Inputs, Level 1 [Member] | U.S. Government Agency Issues Long Term [Member]
|
|
|
Non-current marketable securities: |
|
|
U.S. government agency issues - Non current |
8,360
|
7,169
|
Fair Value, Inputs, Level 2 [Member]
|
|
|
Financial assets: |
|
|
Cash and cash equivalents |
|
|
Non-current marketable securities: |
|
|
Total |
|
|
Other liabilities: |
|
|
Acquisition-related consideration |
|
|
Fair Value, Inputs, Level 2 [Member] | Money Market Accounts [Member]
|
|
|
Financial assets: |
|
|
Cash and cash equivalents |
|
|
Fair Value, Inputs, Level 2 [Member] | U.S. Government Agency Issues Short Term [Member]
|
|
|
Available for sale marketable securities: |
|
|
U.S. government agency issues - Current |
|
|
Fair Value, Inputs, Level 2 [Member] | U.S. Government Agency Issues Long Term [Member]
|
|
|
Non-current marketable securities: |
|
|
U.S. government agency issues - Non current |
|
|
Fair Value, Inputs, Level 3 [Member]
|
|
|
Financial assets: |
|
|
Cash and cash equivalents |
|
|
Non-current marketable securities: |
|
|
Total |
|
|
Other liabilities: |
|
|
Acquisition-related consideration |
|
5,656
|
Fair Value, Inputs, Level 3 [Member] | Money Market Accounts [Member]
|
|
|
Financial assets: |
|
|
Cash and cash equivalents |
|
|
Fair Value, Inputs, Level 3 [Member] | U.S. Government Agency Issues Short Term [Member]
|
|
|
Available for sale marketable securities: |
|
|
U.S. government agency issues - Current |
|
|
Fair Value, Inputs, Level 3 [Member] | U.S. Government Agency Issues Long Term [Member]
|
|
|
Non-current marketable securities: |
|
|
U.S. government agency issues - Non current |
|
|