Fair Value Measurement Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	$ 3,990	$ 0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	3,990
Contingent consideration	4,571	6,016
Assets and liabilities net fair value disclosure	(581)
Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	0
Contingent consideration	0	0
Assets and liabilities net fair value disclosure	0
Level 2 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	3,990
Contingent consideration	0	0
Assets and liabilities net fair value disclosure	3,990
Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Short-term investments	0
Contingent consideration	4,571	6,016
Assets and liabilities net fair value disclosure	$ (4,571)