Fair Value Measurements (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	6 Months Ended								6 Months Ended
	Oct. 31, 2013	Oct. 31, 2013 Carrying Value [Member]	Jan. 31, 2013 Carrying Value [Member]		Oct. 31, 2013 Fair Value Measurements [Member] Fair Value Measurements - Level 1 [Member]	Jan. 31, 2013 Fair Value Measurements [Member] Fair Value Measurements - Level 1 [Member]		Jan. 31, 2013 Fair Value Measurements [Member] Fair Value Measurements - Level 2 [Member]		Oct. 31, 2013 Fair Value Measurements [Member] Fair Value Measurements - Level 3 [Member]	Jan. 31, 2013 Fair Value Measurements [Member] Fair Value Measurements - Level 3 [Member]
Financial Assets:
Restricted deposits held at fair value		$ 2,869	$ 2,861		$ 2,869	$ 2,861
Preferred units of SolmeteX, LLC	432	455								455
Financial Liabilities:
Contingent earnout of acquired businesses				[1]			[1]		[1]			[1]

[1] The fair value of the contingent earnout of acquired businesses was determined using a mark-to-market modeling technique based on significant unobservable inputs calculated using a discounted future cash flows approach. Key assumptions include a discount rate of 41.2% and annual revenues of acquired businesses ranging from $1.5 million to $6.1 million over the life of the earnout. On July 31, 2012, the contingent earnout was reassessed and, based on our estimates of the likelihood of future revenues subject to the earnout provisions, assigned no value. Our conclusions have not changed since that time.