Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) (Fair Value, Measurements, Recurring, USD $) In Thousands, unless otherwise specified	Apr. 30, 2015	Jan. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	$ 3,068	$ 4,563
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	$ 3,068	$ 4,563