Fair Value Measurements - Fair Value Hierarchy for Financial Assets and Liabilities Measured at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Oct. 31, 2013	Jan. 31, 2013
Assets:
Money market funds	$ 15,007
Other assets - certificate of deposit	525	525
Level 1 [Member]
Assets:
Money market funds	15,007
Other assets - certificate of deposit	525	525
Level 2 [Member]
Assets:
Money market funds
Other assets - certificate of deposit
Level 3 [Member]
Assets:
Money market funds
Other assets - certificate of deposit