Description of the Business and Basis of Presentation - Schedule of Net Revenues by Service Category (Detail) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Product Information [Line Items]
Revenues	$ 127,564,000	$ 63,452,000	$ 280,785,000	$ 167,964,000
Power Industry Services [Member]
Product Information [Line Items]
Revenues	125,660,000	61,103,000	275,902,000	160,392,000
Core Services [Member] | Power Industry Services [Member]
Product Information [Line Items]
Revenues	125,660,000	46,858,000	275,902,000	146,147,000
Project Development Services [Member] | Power Industry Services [Member]
Product Information [Line Items]
Revenues		$ 14,245,000		$ 14,245,000