Summary of Significant Accounting Policies - Schedule of Net Revenues by Service Category (Detail) (USD $)	3 Months Ended								12 Months Ended
	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Product Information [Line Items]
Revenues	$ 59,491,000	$ 63,452,000	$ 57,864,000	$ 46,648,000	$ 57,840,000	$ 74,486,000	$ 82,619,000	$ 63,690,000	$ 227,455,000	$ 278,635,000	$ 141,850,000
Power Industry Services [Member]
Product Information [Line Items]
Revenues									218,649,000	261,327,000	132,519,000
Core Services [Member] | Power Industry Services [Member]
Product Information [Line Items]
Revenues									191,597,000	261,327,000	132,519,000
Project Development Services [Member] | Power Industry Services [Member]
Product Information [Line Items]
Revenues									$ 27,052,000